MRCP Infectious disease notes.

MRCP Infectious Disease
Notes
BY DR. SHERIF ELBADRAWY
MRCP Infectious Disease Revision notes
Dr.Sherif Elbadrawy

Causes of Bacterial meningitis ? - Streptococcus pneumoniae
- Neisserie meningitidis
- Listeria rnonocytogenes
Causes of Otitis media ? - Streptococcus pneumonia
Causes of Community-acquired-
Pneumonia ?
- Streptococcus pneumonae
- Haemophitus inﬂuenzae
- Staphylococcus aureus
Causes of Atypical Pneumonia ? - Mycoptasma pneumoniae
- Chlamydia pneumoniae
- Legioneiia pneumophiia
Causes of Eye infections ? - Staphylococcus aureus
- Neissoria gonorrhoeae
- Chlamydia trachomatis
Dr.Sherif Elbadrawy
Dr. Sherif
Elbadrawy
Digitally signed by Dr. Sherif Elbadrawy
DN: cn=Dr. Sherif Elbadrawy, o=Westmead
Hospital, ou,
email=sherif_badrawy@yahoo.com, c=AU
Date: 2017.01.18 19:30:37 +11'00'

Causes of Sexually transmitted
diseases ?
- Chlamydia trachomatis
- Neisseria gonorrhoeae
- Treponema pallidum
- Ureaplasma urealyticum
- Haemophilus ducreyi
Causes of Skin infections ? - Staphylococcus aureus
- Streptococcus pyogenes
- Pseudomonas aeruginosa
Causes of Urinary tract infections ?
- Escherichia col
- Other Enterobactedaceae
- Staphylococcus saprophyticus
- Pseudomonas aeruginosa
Gram (P)ositive cocci ? sta(P)hylococci + stre(P)tococci
(including enterococci)
Gram (N)egative cocci ? (N)eisseria meningitidis +(N)eisseria
gonorrhoeae, also Moraxella
Dr.Sherif Elbadrawy

Gram positive bacilli ?
☀ Actinomyces
☀ Bacillus antracis (anthrax)
☀ Clostridium
☀ Diphtheria: Corynebacterium
diphtheriae
☀ Listeria monocytogenes
Antibiotics with anti-anaerobic
activity ?
☆ Penicillins
☆ Cephalosporins (except ceftazidime)
☆ Metronidazole
☆ Clindamycin
☆ Erythromycin
☆ Tetracycline
Antibiotics with NO anti-anaerobic
activity ?
☆ Gentamicin
☆ Ciprofloxacin
☆ Ceftazidime
Incubation Period Longer than 3
weeks ?
☆ Infectious mononucleosis
☆ Cytomegalovirus
☆ Viral hepatitis
☆ HIV
Incubation Period 2 - 3 weeks ? ☆ Mumps
☆ Rubella
☆ Chickenpox
Dr.Sherif Elbadrawy

Incubation Period 1 - 2 weeks ?
☆ Malaria
☆ Measles
☆ Dengue fever
☆ Typhoid
Incubation Period Less than 1 week ?
☆ Scarlet fever
☆ Influenza
☆ Diphtheria
☆ Meningococcus
Vaccine using Fragment/Extracts of
the organism or virus ?(recombinant
DNA technology)
✰ diphtheria
✰ pertussis ('acellular' vaccine)
✰ heptitis B
✰ meningococcus, pneumococcus,
hemophilus
Composition of cholera Vaccine ?
inactivated Inaba and Ogawa strains of
Vibrio cholerae together with
recombinant B-subunit of the cholera
toxin
Post-Exposure Prophylaxis in
Hepatitis A ?
IV IG or hepatitis A vaccine
Dr.Sherif Elbadrawy

Hepatitis B ?
☠ HBsAg positive source :-
✾ a known responder to HBV vaccine→ a booster dose should be given.
✾ If in the process of being vaccinated or are a nonresponder→
IV IG + vaccine
☠ Unknown source :-
✾ a known responder to HBV vaccine→a booster dose of
HBV vaccine.
✾ If a nonresponder→ IV IG + vaccine
✾ If in the process of being vaccinated →an accelerated course of HBV
vaccine
Hepatitis C ?
Monthly PCR - if seroconversion ➜
interferon +/- ribavirin
Post-Exposure Prophylaxis in HIV ?
✿ A combination of oral antiretrovirals (e.g.
Tenofovir, emtricitabine, lopinavir and ritonavir)
ASAP (i.e. Within 1-2 hours, but may be started up to
72 hours following exposure) for 4 weeks
✿ Serological testing at 12 weeks following
completion of post-exposure prophylaxis
✿ ↓ risk of transmission by 80%
Varicella zoster ?
✿ Antibody Testing
✿ VZIG for IgG negative pregnant
women /immunosuppressed
Indictions of Tetanus vaccine ?
✿ given in the UK as part of the routine
immunisation
☀ high-risk wounds (e.g. compound fractures, delayed
surgical intervention, severely devitalised tissue) :-
✿ Vaccinated➜ IM IG.
✿ Incomplete or unknown vaccination history ➜ IM
IG + a dose of tetanus vaccine.
Dr.Sherif Elbadrawy

Indictions of Meningococcal Vaccine
?
Meningococcal vaccine is routinely indicated at the age 11
visit. The vaccine is also indicated for adults with the
following circumstances:
• Asplenia
• Terminal complement deficiency
• Military recruits
• Residents of college dormitories
• Travelers to Mecca or Medina in Saudi Arabia for the
Hajj (pilgrimage)
Tetanus ➜ Causative organism,Mode
of infection, mechanism of toxicity ?
Clostridium tetani➜Tetanus spores
in soil → introduced into the body
from a wound➜tetanospasmin
exotoxin➜prevents release of GABA
Clinical picture of Tetanus ?
❒ Prodrome fever, lethargy, headache
❒ Trismus (lockjaw)
❒ Risus sardonicus
❒ Opisthotonus (arched back,
hyperextended neck)
❒ Spasms (e.g. Dysphagia)
Rx of Tetanus ?
❁ MV & ms relaxants
❁ IM IG. for high-risk wounds (e.g.
Compound fractures, severely
devitalised tissue)
❁ Metronidazole is DOCH
When to suspect HIV seroconversion
?
☹ a glandular fever 3-12 weeks after infection
☹ symptomatic in 60-80% of patients (Man returns
from trip abroad with maculopapular rash and flu-
like illness - think HIV seroconversion).
☹ For questions involving businessmen always
consider sexually transmitted infections.
Dr.Sherif Elbadrawy

Clinical picture of HIV
seroconversion (glandular fever)?
☆ HIV seroconversion resembles infection with cytomegalovirus,
toxoplasmosis and the Epstein-Barr virus
◥ Lymphadenopathy
◥ Diarrhoea
◥ Maculopapular rash
◥ Sore throat
◥ Malaise, myalgia, arthralgia
◥ Mouth ulcers
◥ Rarely meningoencephalitis
Dx of HIV seroconversion ?
◥ ELISA, conﬁrmed by Western blotting
◥ Antibodies to HIV may not be present
◥ HIV PCR and p24 antigen tests can
confirm diagnosis
◥ The CD4+ count is not used for
diagnostic purposes
immunological changes in
progressive HIV ?
❀ Reduction in CD4 count
❀ Increase B2-Microglobulin (IBM)
❀ Decrease IL-2 production (DIL=DELL) 〘
IBM & DELL 〙
❀ Polyclonal B-cell activation
❀ ↓ NK cell function
❀ ↓ delayed hypersensitivity responses
Contraindicated Vaccines in HIV +ve
pt ? (Cholera
SABIN's Beautiful, INcredible!) (all
are live attenuated except for
cholera)
❀ Cholera
❀ SABIN's = Sabin's polio virus
(oral)
❀ B = BCG
❀ IN = influenza (intranasal)
Vaccines that can be used if CD4 >
200 in HIV +ve pt ? (Varicella Yellow
MMR)
❀ Varicella
❀ Yellow Fever
❀ MMR
Dr.Sherif Elbadrawy

Causes of Diarrhea in HIV +ve pt ?
❂ CRYPTOSPORIDIUM (most common)+
other protozoa.
❂ Effects of the virus itself (HIV enteritis)
❂ Cytomegalovirus
❂ Mycobacterium avium intracellulare
❂ Giardia
Cryptosporidium infection in HIV
+ve pt ?
☆ MCC of DIARRHEA in HIV patients.
☆ incubation period of 7 days.
☆ Ziehl-Neelsen stain of the stool ➜
characteristic red cysts of
Cryptosporidium.
☆ Difficult to Rx (supportive therapy)
Mycobacterium avium intracellulare
infection in HIV +ve pt ?
❐ CD4 < 50.
❐ fever, sweats, abdominal pain &
DIARRHEA ± hepatomegaly and ↑LFTs
❐ Dx ➜ blood cultures and BM aspiration
❐ Rx ➜ rifampicin, ethambutol and
clarithromycin
Factors which ↓ vertical transmission
of HIV ?
✪ Maternal antiretroviral therapy
✪ Neonatal antiretroviral therapy
✪ Mode of delivery (caesarean
section)
✪ Infant feeding (bottle feeding)
Should pregnant women do
screening for HIV ?
【YES】
NICE guidelines recommend offering
HIV screening to all pregnant women
Dr.Sherif Elbadrawy

Whom should be offered
antiretroviral therapy in pregnant
HIV +ve pt ?
✪ 【ALL】pregnant HIV +ve pt
✪ If not using before ➜ start at 28
and 32 weeks of gestation ➜
continue intrapartum.
Mode of delivery in pregnant HIV
+ve pt ?
✪ Elective CS
✪ zidovudine infusion before CS
✪【Zidovudine 】 orally to the
neonate for 4 to 6 weeks.
✪ AVOID breast feed
Best Neonatal antiretroviral therapy
to protect against HIV of the baby in
HIV +ve mother ?
✪【Zidovudine 】 orally to the
neonate for 4 to 6 weeks.
✪ AVOID breast feed
Etiology of Kaposi's sarcoma ?
HHV-8 (Human Herpes Virus 8)
【purple papules】 or plaques on the:-
✿ skin➜ ± ulcerate
✿ mucosa (e.g. GIT and respiratory tract)➜ massive
hemoptysis and pleural effusion
✿ HAART➜ ↑CD4 count ➜ improves Kaposi's sarcoma
✿ Radiotherapy + Surgical resection may be used
✿ Intralesional injections of vincristine or interferon
Clinical picture of Kaposi's sarcoma ?
【purple papules】 or plaques on the:-
✿ skin➜ ± ulcerate
✿ mucosa (e.g. GIT and respiratory
tract)➜ massive
hemoptysis and pleural effusion
Dr.Sherif Elbadrawy

Rx of Kaposi Sarcoma ?
✿ HAART➜ ↑CD4 count ➜ improves
Kaposi's sarcoma
✿ Radiotherapy + Surgical resection may
be used
✿ Intralesional injections of vincristine or
interferon
most common opportunistic infection
in AIDS ?
PCP
Which HIV pt. to give PCP
prophylaxis ?
All patients with a CD4 count <
200/mm³
Dx of PCP ?
✿ most common opportunistic infection in AIDS
✿ All patients with a CD4 count < 200 ➜ PCP prophylaxis
✿ Clinical pulmonary ➜ non-specific(Dyspnea,Dry cough,Fever,Very
few chest signs) Exercise-induced desaturation
✿ Extrapulmonary ➜ hepatosplenomegaly ,Lymphadenopathy ,Choroid
lesions
✿ CXR ➜ typically【 B/L INTERSTITIAL PULMONARY
INFILTRATES】 but can present with other x-ray findings e.g. lobar
consolidation. May be normal
✿ Sputum ➜ fails to Dx PCP
✿ BAL➜Dx PCP (SILVER STAIN)
Rx of PCP ?
✿ Co-trimoxazole
✿ IV pentamidine in severe cases
✿ Steroids if hypoxic (if pO2 <
9.3kpa)
Dr.Sherif Elbadrawy

The most common cause of biliary
disease in patients with HIV is ?
【sclerosing cholangitis】 due to
infections such as CMV,
Cryptosporidium and Microsporidia
Pancreatitis é HIV infection dt ? anti-retroviral treatment
【didanosine】or by opportunistic
infections e.g. CMV.
Definition of Immune reconstitution
inflammatory syndrome (IRIS) ? ( ‫ﻋ‬‫ﺎ‬‫د‬
‫ﻟ‬‫ﯾ‬‫ﻧ‬‫ﺗ‬‫ﻘ‬‫م‬ )
when the immune system begins to recover (few
weeks after starting Anti-retroviral Rx)➜ responds
to a previously acquired opportunistic infection with
an overwhelming inflammatory response
➜paradoxically makes the symptoms of infection
worse.
✼【TB】 and cryptococcal meningitis.
Infections most commonly associated
with IRIS ?
【TB】 and cryptococcal meningitis.
Bacterial Meningitis CSF ?
✯ Cloudy
✯ Low Glucose (< 1/2 plasma)
✯ High Protein (> 1 g/l)
✯ 10 - 5,000 POLYMORPHS
Dr.Sherif Elbadrawy

Viral Meningitis CSF ?
✯ Clear/cloudy
✯ Normal Glucose ➜ mumps & herpes
encephalitis ± low glucose
✯ Normal/raised Protein
✯ 15 - 1,000 LYMPHOCYTES
TB Meningitis CSF ?
✯ Fibrin web
✯ Low Glucose (< 1/2 plasma)
✯ High Protein (> 1 g/l)
✯ 15 - 1,000 LYMPHOCYTES
✯ PCR > better than Ziehl-Neelsen stain
Contraindications to LP ?
● Possible ↑ ICP
●Thrombocytopenia or other
bleeding diathesis (including
ongoing anticoagulant therapy)
●Suspected spinal epidural abscess
The most important α hemolytic
Streptococcus ?
● Streptococcus pneumoniae
(pneumococcus).
● a common cause of ➜ pneumonia,
meningitis and otitis media. Another
example is Strept viridans.
● Penicillin is the antibiotic of choice
The most important Group A β
hemolytic Streptococcus ?
● Streptococcus pyogenes
● erysipelas, impetigo, cellulitis, type 2
necrotizing fasciitis & pharyngitis/tonsillitis
● Immunological reactions➜ rheumatic fever
or post-streptococcal glomerulonephritis
● Erythrogenic toxins ➜ scarlet fever
● Penicillin is the antibiotic of choice
Dr.Sherif Elbadrawy

The most important Group B β
hemolytic Streptococcus ?
Streptococcus agalactiae ➜ neonatal
meningitis and septicemia
CDC diagnostic criteria for
Staphylococcal toxic shock syndrome
?
✰ Fever: temperature > 38.9ºc
✰ Hypotension: SBP < 90 mmHg
✰ RASH Diffuse erythematous
✰ ±infected tampons
✰ Desquamation of rash, esp of the palms &
soles
✰ ≥ 3 organ systems
Types of Necrotising fasciitis
according to causative organism ?
✰ Type 1 is caused by mixed aerobes
& anaerobes (often occurs post-
surgery in diabetics)
✰ Type 2 is caused by Streptococcus
pyogenes
Clinical picture of Necrotising
fasciitis ?
✿ progressive destruction of fascia and SC
fat; ms is frequently spared dt ↑ blood
supply.
Acute ➜ skin color from red-purple to
patches of blue-gray ➜Extremely tender ➜
skin breakdown with bullae ➜ frank
gangrene
Rx of Necrotising fasciitis ? ✿ Urgent surgical debridement
✿ IV antibiotics
Dr.Sherif Elbadrawy

Listeria monocytogenes mode of
infection ?
via CONTAMINATED
FOOD,unpasteurised dairy products
Vertical transmission➜ miscarriage
Clinical picture of Listeria infection ?
❂ CONTAMINATED FOOD,unpasteurised dairy products
➜【meningitis, meningoencephalitis, or bacteremia】in
IMMUNOSUPPRESSED PATIENTS, EXTREMES OF AGE (neonates
and elderly) and PREGNANT.
♞ diarrhoea, flu-like illness
♞ pneumonia , meningoencephalitis
♞ ataxia and seizures
❂ blood cultures. CSF may reveal a pleocytosis, with 'tumbling motility'
on wet mounts
❂ IV amoxicillin/ampicillin and gentamicin (resistant to
cephalosporins)
Dx of Listeria meningitis ? blood cultures. CSF may reveal a
pleocytosis, with 'tumbling motility'
on wet mounts
Rx of Listeria meningitis ?
Listeria meningitis should be treated
with IV amoxicillin/ampicillin and
gentamicin (resistant to
cephalosporins)
Clinical picture of Anthrax ?
❂ 【painless black eschar】 (cutaneous
'malignant pustule', but no pus)
❂ May cause marked edema
❂ Anthrax can cause gastrointestinal
bleeding
✿ ciprofloxacin
Dr.Sherif Elbadrawy

Rx of Anthrax ? ✿ ciprofloxacin
Who should be screened for MRSA?
✿ All elective admissions except (day
patients➜ terminations
of pregnancy & ophthalmic surgery.
Patients admitted to mental health trusts)
✿ all emergency admissions
How should a patient be screened for
MRSA?
Nasal swab and skin lesions or
wounds
Treatment of invasive MRSA
infections in adults ?
✿ VANCOMYCIN
✿ DAPTOMYCIN
✿ TEICOPLANIN
✿ TIGECYCLINE
✿ QUINUPRISTIN & DALFOPRISTIN
✿ TELAVANCIN a semisynthetic lipoglycopeptide (-) cell wall
synthesis
✿ ARBEKACIN a semisynthetic aminoglycoside antibiotic
✿ CEFTAROLINE, a fifth generation cephalosporin
✿ Adjunctive agents → Rifampin & Fusidic acid
Etiology of Legionnaire's disease ?
✿ Legionella pneumophilia (intracellular
bacteria)
✿ colonizes water tanks and hence
questions may hint at air-conditioning
systems or foreign holidays. Person-to-
person transmission is not seen
Dr.Sherif Elbadrawy

Clinical picture of Legionnaire's
disease ?
✿ Flu-like symptoms
✿ Dry cough
✿ Lymphopenia
✿ SIADH➜ Hyponatremia
✿ Deranged LFTs
✿ Urinary antigen
✿ Erythromycin
Dx of Legionnaire's disease ? Urinary antigen
Rx of Legionnaire's disease ? Erythromycin
Etiology of Leptospirosis (Weil's
disease) ?
❂ spirochaete Leptospira ➜spread by
contact with infected rat urine.( ‫ا‬‫ﻟ‬‫ﻔ‬‫ﺎ‬‫ر‬ ‫ﺑ‬‫و‬‫ل‬ )
❂ questions referring to sewage workers,
farmers, vets or people who work in abattoir.
Clinical picture of Leptospirosis ?
✿ Fever
✿ Flu-like symptoms ,no productive cough
✿ Jaundice
✿ (hepatorenal syndrome)(seen in 50% of patients)
✿ Weil's disease = Jaundice + Renal failure.
✿ Subconjunctival hemorrhage
✿ ±meningitis
❏ LP Dx meningitis
❏ High-dose 【benzylpenicillin or doxycycline】
Dr.Sherif Elbadrawy

Rx of Leptospirosis ? ❏ Do LP 1st to Dx meningitis
❏ High-dose benzylpenicillin or
doxycycline
Etiology of Acute epiglottitis ? Hemophilus influenzae type B.
Clinical picture of Acute epiglottitis ?
❊ Hemophilus influenzae type B.
❊ children bw 2 and 6 years.
✿ Rapid onset
✿ Unwell, toxic child
✿ Stridor
✿ Drooling of saliva
✿ Rapid Dx & Rx is essential to prevent airway
obstruction
Etiology of Lyme Disease ? ✰ Borrelia burgdorferi (USA)
✰ Borrelia afzelii (EUROPE)
✰ Borrelia garinii(EUROPE)
Clinical picture of Lyme Disease ?
【Early features】
☆ ERYTHEMA CHRONICUM MIGRANS (small papule often at
site of the tick bite which develops into a larger annular lesion with
central
clearing, occurs in 70% of patients)
☆ Systemic symptoms: malaise, fever, arthralgia
【Later features】
☆ CVS: heart block, myocarditis
☆ Neurological: cranial nerve palsies, meningitis
☆ Polyarthritis
Dr.Sherif Elbadrawy

Rx of Lyme Disease ?
☆【 Doxycycline】 (Should not be used for children <
8 years or pregnant or lactating women).
☆ ceftriaxone if disseminated disease
☆ Jarisch-Herxheimer reaction sometimes seen :
fever, rash, tachycardia after first dose of antibiotic
(> seen in syphilis, another spirochaetal disease) ➜
spontaneously settle after around four hours
screening for TB ? Heaf test & Mantoux test (more
accurate) ➜ to see if BCG is needed
Interpretation of Mantoux test ? Erythema & induration > 10mm =
positive result ➜ previous exposure
including BCG
Interpretation of Mantoux test ?
(details)
False negative Heaf & Mantoux tests
in ?
✪ Miliary TB
✪ Sarcoidosis
✪ HIV
✪ Lymphoma
✪ Very young age (e.g. < 6 months)
Dr.Sherif Elbadrawy

Rx of active tuberculosis ?
❑ Initial phase - first 2 months (RIPE)
❁ Rifampicin
❁ Isoniazid
❁ Pyrazinamide
❁ Ethambutol
❑ Continuation phase - next 4 months
❁ Rifampicin
❁ Isoniazid
Rx of Latent tuberculosis ? isoniazid alone for 6 months
Meningeal tuberculosis ? prolonged period (at least 12 months)
with the addition of steroids
What's Directly observed therapy for
TB ?
❑ 3 per week dosing regimen may be
indicated in certain groups, including:
❁ Homeless people with active tuberculosis
❁ Patients who are likely to have poor
concordance
❁ All prisoners with active or latent
tuberculosis
SEs of Anti-TB medications ?
☠ All of them cause HEPATOTOXICITY 〖 + 〗
❏ Rifampin ➜ enzyme inducer [Revs up] , Red urine
❏ Isoniazid ➜ PERIPHERAL NEUROPATHY➜ Rx by
PYRIDOXINE, Enzyme INHibitor [INH = INHibits]
❏ Pyrazinamide ➜HYPERURICEMIA
❏ Ethambutol ➜ EYE ➜Optic neuritis/color vision
Dr.Sherif Elbadrawy

Use of Streptomycin in TB ? aminogycoside used in resistant TB
Rx of Asymptomatic patient with Hx
of TB exposure and Heaf Test
positive ?
dual therapy (RI) for 5 months or
INH for 6 months.
Etiology of Leprosy ? Mycobacterium leprae
Mycobacterium lepromatosis.
Clinical picture of Leprosy ?
Initially asymptomatic for 5 to 20
years. ➜ granulomas of the nerves,
respiratory tract, skin (Nodular skin
lesions), and eyes, hypopigmented
skin lesions with reduced sensation.
Dx of Leprosy ?
Skin biopsy and needle test in cold area (ear
lobule & elbow) ➜ Lepromatous leprosy
➜slowly growing.【ACID ALCOHOL FAST
BACELLI】
tuberculoid leprosy ➜strong T cell immune
response with no bacelli in the affected area
skin biopsy.
Dr.Sherif Elbadrawy

Rx of Leprosy ?
☯ Pauci-bacillary leprosy (<5 lesions)
rifampicin & dapsone for 6 months
☯ Multi-bacillary leprosy (>5 lesions)
rifampicin, dapsone & clofazimine for 12
months
Feature of severe malaria ? STAPH +
Complications
▼ S➜ Schizonts on a blood film
▼ T➜ Temperature > 39 °c
▼ A➜ Anemia (severe)
▼ P➜ Parasitemia > 2%
▼ H➜ Hypoglycemia
▼ + ANY Complication
Complications of malaria ?
▼ Brain➜ seizures, coma
▼ Lungs➜ ARDS
▼ Kidney➜ ARF: blackwater fever dt
intravascular
hemolysis
▼ Blood➜ DIC
▼ Pancreas➜ Hypoglycemia
Rx of Uncomplicated falciparum
malaria ?
✫ Strains resistant to chloroquine are prevalent in
Asia and Africa
✫ artemisinin ➜ first-line therapy
❐ artemether plus lumefantrine,
❐ artesunate plus amodiaquine, or mefloquine,or
sulfadoxine-pyrimethamine,
❐ dihydroartemisinin plus piperaquine
❐ Pregnant + malaria ➜ Quinine
Rx of Severe falciparum malaria ?
❂ A parasite counts >2% IV Rx 【IV
ARTESUNATE】
❂ If parasite count > 10% ➜ exchange
transfusion
❂ Shock may indicate coexistent bacterial
septicemia - malaria rarely causes
hemodynamic collapse
Dr.Sherif Elbadrawy

the most common cause of Non-
falciparum malaria ?
【Plasmodium vivax】 ➜ Central
America & India
other causes ➜Plasmodium ovale &
Plasmodium malariae➜Africa
Rx of Non-falciparum malaria ? almost always chloroquine sensitive
destroy liver hypnozoites ➜ by
Primaquine (vivax & ovale)
prophylaxis of malaria ?
⓵ Atovaquone + proguanil (Malarone) ➜ GI upset
⓶ Chloroquine ➜ CI in epilepsy
⓷ Doxycycline ➜ Photosensitivity, Oesophagitis
⓸ Mefloquine ➜ Dizziness, Neuropsychiatric
disturbance, CI in epilepsy
✪ Pregnant ➜ chloroquine, proguanil + folate,
Atovaquone + proguanil (Malarone) + folate
✪ children over 2 months ➜ diethyltoluamide (DEET)
✪ children over 12 years ➜ doxycycline
Etiology of Leishmaniasis ?
intracellular protozoa
LEISHMANIA➜to humans by sand
flies➜incubation period up to 10
years.
Types of Leishmaniasis ? ✫ Cutaneous leishmaniasis
✫ Mucocutaneous leishmaniasis
✫ Visceral leishmaniasis (kala-azar)
Dr.Sherif Elbadrawy

Clinical picture of Cutaneous
leishmaniasis ?
✫ Leishmania tropica or Leishmania
mexicana
✫ Crusted lesion at site of bite➜
ulcer
Clinical picture of Mucocutaneous
leishmaniasis ?
✫ Leishmania brasiliensis
✫ Skin lesions➜ spread to involve
mucosae of nose, pharynx
Clinical picture of Visceral
leishmaniasis (kala-azar) ?
✫ Leishmania donovani
✫ Mediterranean, Asia, South America, Africa
✫ Massive splenomegaly, hepatomegaly➜
Pancytopenia
✫ ↑ Fever,Typically ↓ appetite➜ weight loss (may be
paradoxical ↑ appetite + weight loss )
Types of Trypanosomiasis ?
African trypanosomiasis (sleeping
sickness)
American trypanosomiasis (Chagas'
disease)
Clinical picture of African
trypanosomiasis(sleeping sickness)?
✱ Trypanosoma gambiense in West Africa
✱ Trypanosoma rhodesiense in East Africa.
➜Both spread by 【tsetse fly】.
❂ rhodesiense ➜acute course➜Trypanosoma
chancre - tender SC nodule ➜post Cx
lymphadenopathy➜ Meningoencephalitis
Dr.Sherif Elbadrawy

Rx of African
trypanosomiasis(sleeping sickness)?
Early disease: IV pentamidine or
suramin
Later disease or CNS involvement: IV
melarsoprol
Clinical picture of American
trypanosomiasis (Chagas' disease) ?
✱ Trypanosoma cruzi.
❁ Acute Chagas' disease ➜95% asymptomatic ±
CHAGOMA (an erythematous nodule at site of infection)
+ periorbital edema
❁ Chronic Chagas' disease:-
❅ HEART➜ Myocarditis ➜ HF & arrhythmias ➜ (leading
cause of death)
❅ GIT ➜ megaesophagus ➜dysphagia & megacolon ➜
constipation.
Rx of American trypanosomiasis
(Chagas' disease) ?
❍ Benznidazole or nifurtimox
❍ Chronic Rx the complications e.g.
heart failure
Etiology of Schistosomiasis ?
♕ Schistosoma Hematobium➜ urinary
schistosomiasis
【hematobium = hematuria】
Schistosomiasis is the most common cause of bladder
calcification worldwide
♕ Schistosoma mansoni➜ intestinal schistosomiasis
NB: Schistosoma mansoni & japonicum ➜ mesentric
veins is the final distenation ➜ GIT symptoms.
Clinical picture of Schistosoma
Hematobium ?
a 'swimmer's itch' in patients who have recently
returned from Africa.
Schistosoma Hematobium➜Frequency,Hematuria
&Bladder calcification.
a risk factor for squamous cell bladder cancer
Single oral dose of 【PRAZIQUANTEL】
Dr.Sherif Elbadrawy

Rx of Schistosoma Hematobium ? Single oral dose of
【PRAZIQUANTEL】
Clinical picture of Rabies ?
Prodrome: headache, fever, agitation
HYDROPHOBIA: water-provoking
muscle spasms
Hypersalivation
What to do after an animal bite in at
risk countries ?
❊ If immunised➜ 2 doses of vaccine
❊ If not immunised ➜ (HRIG) + full
vaccination
❊ Cleanse wound
❊ CO-AMOXICLAV (DOCH)
❊ If penicillin-allergic ➜ doxycycline +
metronidazole is recommended
Etiology of Cat scratch disease ? Bartonella henselae Gram negative
rod
Clinical picture of Cat scratch disease
?
❍ Bartonella henselae Gram negative
rod
❍ fever ,headache, malaise
❍ regional lymphadenopathy
Dr.Sherif Elbadrawy

Etiology of Chickenpox ? primary infection with VZV
shingles is reactivation of dormant
virus in dorsal root ganglion
MOST CONTAGIOUS ORGANISM ? VZV
Mode of transmission of VZV ?
✱ respiratory route
✱ Through shingles
✱ Infectivity = 4 days before rash, until 5
days after the rash(till all lesions had
scabbed over)
✱ Incubation period = 11-21 days
Clinical picture of VZV ?
✬ Fever initially
✬ Itchy, rash starting on head/trunk
➜ spread.1st macular then papular
then vesicular
✬ Systemic upset is usually mild
Rx of VZV ?
❂ Keep cool, trim nails
❂ Calamine lotion
❂ School exclusion:5 days from start of rash,
until all lesions are crusted & dry.
❂ VZIG (for Immunocompromised patients
and newborns with peripartum exposure)➜
If chickenpox develops ➜ IV aciclovir
Dr.Sherif Elbadrawy

complications of VZV ?
❂ Secondary bacterial infection of the
lesions
❂ Pneumonia➜ MC & serious ➜ IV
acyclovir
❂ Encephalitis ± cerebellar
❂ Disseminated hemorrhagic chickenpox
Dx of VZV infection In pregnancy ?
❂ first step is to check antibodies
❂ both mother & fetus can be affected, a
syndrome called fetal varicella syndrome
✺ not immune ➜ VZIG ASAP
✺ oral aciclovir if pregnant women with
chickenpox present within 24 h of rash
Clinical picture of FVS {Fetal
varicella syndrome} ?
✯ before 20 weeks
✯ skin scarring,microphthalmia,
microcephaly & learning disabilities,
limb hypoplasia,
Rx of VZV infection In pregnancy ? ✺ not immune to varicella ➜ VZIG ASAP
✺ oral aciclovir if pregnant women with
chickenpox present within 24 h of rash
Etiology of Measles ?
✺ RNA paramyxovirus
✺ Spread by droplets
✺ Infective from prodrome until 5
days after rash starts
Dr.Sherif Elbadrawy

Clinical picture of Measles ?
✺ Prodrome: irritable, conjunctivitis, fever
✺ Koplik spots (before rash): white spots
('grain of salt') on buccal mucosa
✺ Rash: starts behind ears then to whole
body, discrete maculopapular rash becoming
blotchy & confluent
Complications of Measles ?
[NB:Pancreatitis and infertility may
follow mumps infection]
✺ Encephalitis: 1-2 weeks after the onset of the illness.
✺ Febrile convulsions
✺ Pneumonia, tracheitis
✺ Keratoconjunctivitis, corneal ulceration
✺ Diarrhoea
✺ ↑ incidence of appendicitis
✺ Myocarditis
✺ Subacute sclerosing panencephalitis: very rare, may
present 5-10 years following the illness
Management of contacts of Measles ?
✺ a child not immunized + contact
with measles then MMR (vaccine-
induced measles antibody > rapid
than natural infection)
✺ Use within 72 hours
Etiology of Gonorrhoea ?
Gram negative diplococcus Neisseria
gonorrhoea
Acute infection can occur on any MM
surface, typically genitourinary but
also rectum and pharynx
Clinical picture of Gonorrhoea ?
✺ ♂ urethral discharge, dysuria
✺ ♀ cervicitis ➜ vaginal discharge
✺ Rectal and pharyngeal infection is usually
asymptomatic, but may present as rectal bleeding
✺ Local complications➜ urethral strictures,
epididymitis and salpingitis ➜ (infertility).
Disseminated infection may occur
Dr.Sherif Elbadrawy

Rx of Gonorrhoea ?
✺ Cephalosporins ("Oral" Cefixime or
Ceftriaxone "single dose IM") ➜ DOC
✺ Ciprofloxacin is no more DOC dt ↑
resistance to ciprofloxacin
Etiology of Disseminated gonococcal
infection ?
✩ Hematogenous spread from asymptomatic genital
infection.
✩ Triad : 【tenosynovitis, migratory polyarthritis
and dermatitis】 (maculopapular or vesicular)
✩ Later complications ➜ septic arthritis(MCC of
septic arthritis in young adults), endocarditis and
perihepatitis
Etiology of Genital warts ?
(condylomata accuminata)
human papilloma virus HPV
especially types 6 & 11
Which types of human papilloma
virus predispose to cervical cancer ?
(16, 18 & 33)
Clinical picture of Genital warts ?
(condylomata accuminata)
HPV, Small (2 - 5 mm) fleshy
protuberances on the genital regions
+ slightly pigmented
bleeding or itching.
Dr.Sherif Elbadrawy

Rx of Genital warts ? (condylomata
accuminata)
★ Topical podophyllum or cryotherapy➜ first-line
★ Multiple, non-keratinised warts ➜ Topical
podophyllum
★ solitary keratinised warts ➜ cryotherapy,
Imiquimod
★ recurrence is common
★ HPV clear without intervention within 1-2 years
Etiology of Genital Ulcers ?
Syphilis➜Painless
Lymphogranuloma venereum➜Painless
Granuloma inguinale➜Painless
Herpes Simplex Virus➜Painful
Chancroid➜Painful
Dx of Syphilis ?
Treponema pallidum is a very sensitive
organism can't grow on artificial media.
The diagnosis is therefore usually based
on clinical features; serological tests and
microscopic examination of infected
tissue
Serological tests for Dx of Syphilis ?
✾ Cardiolipin tests (not treponeme specific)
✷ VDRL & RPR
✷ Insensitive in late syphilis
✷ Becomes negative after treatment
✾ Treponemal specific antibody tests
✷ TPHA
✷ Remains positive after treatment
Causes of false positive cardiolipin
tests
❂ pregnancy
❂ SLE, anti-phospholipid syndrome
❂ TB
❂ leprosy
❂ malaria
❂ HIV
Dr.Sherif Elbadrawy

Etiology of Lymphogranuloma
venereum ?
Chlamydia trachomatis.
Clinical picture of Lymphogranuloma
venereum ?
Chlamydia trachomatis.
✾ Stage 1: painless pustule ➜ ulcerate
✾ Stage 2: painful inguinal
lymphadenopathy
✾ Stage 3: proctocolitis
Types of Herpes Simplex Virus ?
HSV-1 and HSV-2
it was thought HSV-1 ➜ oral lesions (cold
sores) & HSV-2 ➜genital herpes it is now
known there is considerable overlap
Clinical picture of Herpes Simplex
Virus ?
❂ Cold sores
❂ Painful genital ulceration
❂ Primary infection ➜ ±
gingivostomatitis
Rx of Herpes Simplex Virus ?
❂ Gingivostomatitis: oral aciclovir,
chlorhexidine MW
❂ Cold sores: topical aciclovir
❂ Genital herpes: oral aciclovir,
↑exacerbations ➜ longer term aciclovir
Dr.Sherif Elbadrawy

Etiology of Chancroid ? Hemophilus ducreyi
Clinical picture of Chancroid ?
❃ Hemophilus ducreyi
❃ painful genital ulcers
❃ inguinal lymphadenopathy.
❃ Grey or yellow purulent exudate⇔ Syphilis
is Non-exudative
❃ Soft edge ⇔ Syphilis is Hard (indurated)
edge
Common causes of Vaginal discharge
?
✯ Physiological
✯ Candida➜'Cottage cheese' discharge Vulvitis Itch
✯ Trichomonas vaginalis➜ Offensive, yellow/green,
frothy discharge, Vulvovaginitis Strawberry cervix
✯ Bacterial vaginosis ➜Offensive, thin, white/grey,
'FISHY' discharge
Less common causes of Vaginal
discharge ?
✯ cervical infections such as Chlamydia
and Gonorrhoea ➜rarely the presenting
symptoms
✯ Ectropion
✯ Foreign body
✯ Cervical cancer
Etiology of Bacterial vaginosis (BV) ?
✯ overgrowth of anaerobic organisms➜
【Gardnerella vaginalis】 ➜ ↓ lactobacilli
➜↓ Lactic acid ➜↑ vaginal pH. not a STD
but seen almost exclusively in sexually active
women.
✯ Asymptomatic in 50%
Dr.Sherif Elbadrawy

Amsel's criteria for diagnosis of
Bacterial vaginosis (BV) ?
【Gardnerella vaginalis】
❃ 3 of the following 4 points
✴ Thin, white homogenous discharge
✴ Clue cells on microscopy
✴ Vaginal pH > 4.5
✴ Positive whiff test (addition of
potassium hydroxide ➜ fishy odour)
Complications of Bacterial vaginosis
in pregnancy ?
✯ preterm labour
✯ low birth weight
✯ chorioamnionitis
✯ late miscarriage
✯ oral metronidazole is used throughout
pregnancy.
Rx of Bacterial vaginosis (BV) ?
✯ Oral metronidazole for 5-7 days
✯ 70-80% initial cure rate
✯ Relapse rate > 50% within 3
months
most common sexually transmitted
infection in the UK ?
✯ Chlamydia
✯ caused by Chlamydia trachomatis,
an obligate intracellular pathogen
✯ ≅ 10 % in UK women.
Clinical picture of Genital Chlamydia
infection ?
Asymptomatic in around 70% of
women
Women: cervicitis (discharge,
bleeding), dysuria
Men: urethral discharge, dysuria
Dr.Sherif Elbadrawy

complications of Genital Chlamydia
infection ?
✯ Epididymitis
✯ Pelvic inflammatory disease
✯ Endometritis ➜ 【1st 3 causes➜
Infertility】
✯ ↑ incidence of ectopic pregnancies
✯ Reactive arthritis
✯ Perihepatitis (Fitz-Hugh-Curtis syndrome)
Dx of Genital Chlamydia infection ?
✯ no Traditional cell culture
✯ Ix of choice➜Nuclear Acid Amplification Tests
(NAATs)➜Use Urine (first void urine sample),
vulvovaginal swab or cervical swab
✯ NB: Neisseria Gonorrhoea ➜ Gram stain➜ Gram -
ve diplococci ➜ If the swab showed non-specific
urethritis ➜ Chlamydia is most likely. Both many
times infect together
Screening of Genital Chlamydia
infection ?
screening all sexually active patients
aged 15-24 years
Rx of Genital Chlamydia infection ?
✿ 【 Azithromycin 】〖first-line〗➜single dose➜better compliance
✿ Doxycycline 7 day course ➜may be used but Azithromycin is better dt
better compliance.
✿ pregnant➜ erythromycin or amoxicillin
✿ in ♂ with symptomatic infection partner notification➜ (all partners
from 4 weeks prior to symptoms)
✿ in ♀& asymptomatic ♂ partner notification ➜ ( last 6 months or the
most recent sexual partner)
✿ partners of confirmed Chlamydia Pt ➜treat then test
✿ A test of cure following treatment.
Clinical picture of Chlamydia psittaci
(psittacosis)(parrot disease, parrot
fever) ?
malaise, fever, myalgias and
pneumonia
Exposure to an ill bird and a rash
(Horder's spots) are pathognomonic.
Dr.Sherif Elbadrawy

Rx of Chlamydia psittaci (psittacosis)
?
Erythromycin or tetracyclines are the
drugs of choice.
Rx of Asymptomatic bacteruria in
pregnant women ?
amoxicillin or cephalosporin
Rx of Lower urinary tract infections
in women (cystitis) ?
trimethoprim or nitrofurantoin for 3
days
Rx of acute lower urinary tract
infections in pregnant women ?
amoxicillin or an oral cephalosporin
for 7 days
Rx of acute pyelonephritis ?
✼ hospital admission
✼ a broad-spectrum cephalosporin or a
quinolone for 10-14 days
✼ ciprofloxacin for 7 days or co-
amoxiclav for 14 days
Dr.Sherif Elbadrawy

most common congenital infection in
the UK ?
Cytomegalovirus 〚Maternal
infection is usually asymptomatic〛
congenital Rubella infection ?
PDA = (P)atent DA, (D)eafness,
(A)nterior chamber
【CATARACTS & Glaucoma】 ➜
Anterior chamber
【heart disease (PDA)】
【Sensorineural deafness】
congenital Toxoplasma infection ?
【CEREBRAL CALCIFICATION➜
Hydrocephalus】
【CHORIORETINITIS】 ➜ Posterior
chamber
congenital CMV infection ? 【Growth retardation】
【Purpuric skin lesions】
Less diagnostic features of congenital
Toxoplasmosis, Rubella & CMV ?
〖All of them〗➜ Hepatosplenomegaly,Cerebral
palsy
【Toxoplasmosis】➜ Anemia
【Rubella】➜ Purpuric skin lesions 'Salt and pepper'
,chorioretinitis
Microphthalmia ,Growth retardation
【CMV】➜ Anemia, Sensorineural deafness,
Encephalitiis ,Pneumonitis, Jaundice
Dr.Sherif Elbadrawy

Etiology of Toxoplasmosis ?
Toxoplasma Gondii➜ a protozoa➜ infection via GIT, lung or
broken skin➜the oocysts release trophozoites ➜migrate widely
around the body including to the eye, brain and muscle.
The usual animal reservoir is the CAT
± rats may carry the disease.
Clinical picture of Toxoplasmosis ?
✾ mostly asymptomatic
✾ If symptomatic➜ self-limiting infection
✾ same as infectious mononucleosis
(fever, malaise, and lymphadenopathy).
✾ meningioencephalitis and myocarditis.
(< common)
Dx of Toxoplasmosis ? Antibody test
Sabin-Feldman dye test
Rx of Toxoplasmosis ? Pyrimethamine + Sulphadiazine for
at least 6 weeks.
Mnemonic for Infectious Causes of
Bloody Diarrhea ?
CHESS
Campylobacter
Hemorrhagic E. coli (O157:H7)
Entamoeba histolytica
Salmonella
Shigella
Dr.Sherif Elbadrawy

The most common cause of
Travellers' diarrhea ?
Escherichia coli
at least 3 loose to watery stools in 24
h
± Abdominal pain, fever, nausea,
vomiting or blood in the stool
most common infection from
reheated rice ?
Bacillus cereus infection
Etiology of 'acute food poisoning' ?
Staphylococcus aureus,
Bacillus cereus
Clostridium perfringens.
sudden onset of nausea, vomiting and
diarrhea after the ingestion of a toxin.
Clinical picture of Cholera diarrhea ?
Vibro cholerae - Gram negative bacteria
Profuse rice watery diarrhea
Severe dehydration ➜ weight loss
Not common amongst travellers
Clinical picture of Campylobacter
diarrhea ?
✯ A flu-like prodrome ➜ abdominal pains➜
Fever and diarrhoea ± blood
✯ may be complicated by Guillain-Barre
syndrome
Dr.Sherif Elbadrawy

Campylobacter Rx ?
✯ usually self-limiting
✯ immunocompromised ➜ antibiotics if
severe symptoms [bloody diarrhoea, > 8
stools / day] ➜ clarithromycin
Clinical picture of Amoebiasis
diarrhea ?
Gradual onset bloody diarrhea
Abdominal pain and tenderness
May last for several weeks
Differnt Incubation periods of
Diarrhea ?
✯ 1-6 hrs: Staphylococcus aureus,
Bacillus cereus
✯ 12-48 hrs: Salmonella, Escherichia coli
✯ 48-72 hrs: Shigella, Campylobacter
✯ > 7 days: Giardiasis, Amoebiasis
Rx of Cholera diarrhea ? ✯ Oral rehydration therapy
✯ doxycycline, ciprofloxacin
Etiology of Giardiasis ? flagellate protozoan Giardia lamblia.
It is spread by the faeco-oral route
Dr.Sherif Elbadrawy

Clinical picture of Giardiasis ?
✯ Often asymptomatic
✯ Lethargy, bloating, abdominal pain
✯ Non-bloody diarrhoea
✯ Chronic/prolonged diarrhoea,
malabsorption and lactose intolerance
Dx of Giardiasis ?
Stool microscopy for trophozoite and
cysts are CLASSICALLY NEGATIVE
➜ duodenal fluid aspirates or 'string
tests' (fluid absorbed onto swallowed
string) are sometimes needed.
Rx of Giardiasis ? Metronidazole
Loa Loa CP
▩ CP ➜ pruritus, urticaria, Calabar swellings: transient, swelling
of soft-tissue around joints, 'eye worm' - the dramatic presentation
of subconjuctival migration of the adult worm.
♕ Rx ➜ diethylcarbamazine (DEC),
high loa loa microfilaraemia is associated with encephalopathy
following Rx with either Ivermectin or DEC. dt death of vast
numbers of blood microfilaria.
Both of these drugs are CI if loa loa microfilaraemia > 2500 mf/ml.
Most common E -coli infections in
humans ?
✯ Diarrhoeal illnesse
✯ UTIs
✯ Neonatal meningitis
Dr.Sherif Elbadrawy

Clinical picture of EHEC (E coli
O157:H7) infection ?
✯ Diahrrea
✯ Renal Failure or Impairment
✯ Thrombocytopenia
✯ hemolytic uremic syndrome
✯ hemorrhage➜ ↓ Hb
hemolytic uremic syndrome can be
caused by which bacteria ?
EHEC (E coli O157:H7) infection
spread by contaminated ground beef.
Which disease Can Body louse
transmit ?
✯ Body lice can spread epidemic typhus, trench fever, and louse-
borne relapsing fever.
✯ louse-borne (epidemic) typhus is no longer widespread,
✯ outbreaks of this disease still occur during overcrowedness with
low sanitation:-
◌ times of war,
◌ civil unrest,
◌ natural or man-made disasters,
◌ in prisons
◌ chronic poverty
Clinical picture of Salmonella
infection (Typhoid) ?
❂ headache,fever, and arthralgia
❂ Relative bradycardia
❂ Abdominal pain, distension
❂ Constipation: > in typhoid
❂ Rose spots: > in paratyphoid
complications of Salmonella
infection (Typhoid) ?
❂ Osteomyelitis (Salmonella is MCC in
sickle cell disease Osteomyelitis )
❂ GI bleed/perforation
❂ Meningitis
❂ chronic carriage (1%, more likely if
adult females)
Dr.Sherif Elbadrawy

Types of Shigella bacterial diarrhea ?
S sonnei (e.g. from UK) may be mild,
S flexneri or S dysenteriae
from abroad may cause severe
disease
Rx of Shigella bacterial diarrhea ? Ciprofloxacin
Definition of Pyrexia of Unkown
Origin ?
a fever of > 3 weeks which
undiagnosed after a week in hospital
Etiology of Pyrexia of Unkown Origin
?《 Infections Can Make
Undergraduates Die》 ?
〖Infection (20-40%)〗
❂ TB
❂ endocarditis
❂ EBV
❂ CMV
〖Connective tissue disorders (20%)〗
❂ RA
❂ SLE
❂ Adult-onset Still's disease
❂ Temporal arteritis
〖Malignancy (10-20%)〗
❂ Lymphoma
❂ Leukaemia
❂ HCC
❂ RCC
❂ Atrial myxoma
〖Undiagnosed (20%)〗
〖Drugs〗phenytoin
Clinical picture of African Tick
Typhus ?
dt Rickettsiae conorii
BLACK SPOTS ON THIGH
Hx of tick bites
Low grade fever
Faint macular rash
Dr.Sherif Elbadrawy

Etiology of Rocky Mountain Spotted
Fever ?
Rickettsia,spreads by ticks, common
in USA.
Clinical picture of Rocky Mountain
Spotted Fever ?
❀ Rickettsia,spreads by ticks, common in
USA.
❀ Fever
❀ Rash on hands, feet ➜ peel
❀ Tachycardia with no hypotension (unlike
Staphy Toxic Shock Syndrome)
❀ Rx Doxycycline
Rx of Rocky Mountain Spotted Fever
?(Rickettsia)
Doxycycline
Etiology of Mediterranean Spotted
Fever ?(Boutonneuse fever)
Rickettsia conorii and transmitted by
the dog tick Rhipicephalus
sanguineus
Clinical picture of Mediterranean
Spotted Fever ?(Boutonneuse fever)
↑ FEVERS, MYALGIA and joints pain, severe
headache, photophobia and diarrhea.
bite site ➜ black spots or ulcerous crust
(tache noire).4th day ➜
widespread rash appears, first macular ➜
maculopapular ± petechial.
Dr.Sherif Elbadrawy

Rx of Mediterranean Spotted Fever ? Doxycycline.
Etiology of viral hemorrhagic fever ?
❂ Dengue fever
❂ yellow fever
❂ Lassa fever
❂ Ebola
Given the current outbreak in West Africa, this group
of infections must be considered as a differential in
returning travellers presenting with a fever.
Etiology of Dengue fever ? dengue virus Transmitted by the
Aedes aegypti mosquito
Clinical picture of Dengue fever ?
❀ Dengue virus (Aedes aegypti mosquito)
❀ incubation period of 7 days
❀ Headache (often retro-orbital)
❀ Facial flushing (dengue)
❀ Maculopapular rash (resembling measles)
❀ Thrombocytopenia &↑ LFTs
❀ DIC
❀ Rx ➜ symptomatic ➜ fluid resuscitation, blood
transfusion
Rx of Dengue fever ? symptomatic ➜fluid resuscitation,
blood transfusion
Dr.Sherif Elbadrawy

Etiology of Infectious mononucleosis
(glandular fever) ?
❀ Epstein-Barr virus ( HHV-4).
❀ adolescents and young adults.
Clinical picture of Infectious
mononucleosis (glandular fever) ?
❀ Sore throat,Fever.Palatal petechiae
❀ Lymphadenopathy
❀ Splenomegaly in 50% of patients ➜ ± splenic
rupture
❀ Hepatitis
❀ Malaise, anorexia, headache
❀ lymphocytosis
❀ Hemolytic anaemia
Rx of Infectious mononucleosis
(glandular fever) ?
❀ symptomatic ➜fluid resuscitation,Rest
during the early stages,avoid alcohol
❀ analgesics
❀ avoid contact sports for 8 weeks
➜↓risk of splenic rupture
Malignancies associated with EBV
infection ?
Burkitt's lymphoma
Hodgkin's lymphoma
Nasopharyngeal carcinoma
Criteria Hepatitis E infection ?
RNA virus
faecal-oral route
Common in Asia, Africa & Mexico
significant mortality (about 20%) during
pregnancy
Does not cause chronic disease
no vaccine
Dr.Sherif Elbadrawy

Etiology of Swine Flu ?
influenza A virus and the most
common cause of flu in humans. The
2009 pandemic was caused by a new
strain of the H1N1 virus.
Pts at risk of swine flu ?
Patients with chronic Disease + Pts
on immunosuppressants
Pregnant women
Young children < 5 years old
Clinical picture of swine flu ?
Fever > 38ºC
Myalgia
Lethargy
Headache
Rhinitis
Sore throat
Cough
Diarrhoea and vomiting
may be complicated by ARDS.
Rx of swine flu ? (H1N1) (ARDS)
❀ Oseltamivir (Tamiflu):-
Oral medication, A neuraminidase inhibitor
SEs ➜ NVD & headaches
❀ Zanamivir (Relenza)
Inhaled or IV for acutely ill pts.
A neuraminidase inhibitor
SEs ➜ bronchospasm in asthmatics
Etiology of Erythema infectiosum
(fifth disease or 'slapped-cheek
syndrome') ?
Parvovirus B19
Dr.Sherif Elbadrawy

Clinical picture of Erythema
infectiosum (fifth disease or 'slapped-
cheek syndrome') ?
❂ Parvovirus B19
❂ may be Asymptomatic
❂ lethargy, fever, headache
❂ 'slapped-cheek' rash spreading to proximal
arms and extensor surfaces
❂ Pancytopenia in immunosuppressed
❂ Aplastic crises in sickle-cell disease
Etiology of Orf ?
parapox virus
a condition found in sheep and goats
although it can be transmitted to
humans.
Clinical picture of Orf ?
❂ parapox virus
❂ a condition found in sheep and goats
❂ small, raised,papules ( red-blue)in the
hands and arms ➜↑ in size,become flat-
topped and hemorrhagic
Most common cause of cutaneous
larva migrans ?
ancylostoma braziliense
Common in Central and Southern
America
Strongyloides stercoralis causes what
?
✾ larva currens - similar appearance to cutaneous larva
migrans but moves through the skin at a far greater rate
✾ Acquired percutaneously (e.g. Walking barefoot)
✾ EOSINOPHILIA
✾ pruritus
✾ Abdominal pain, diarrhoea, pneumonitis
✾ May cause gram negative septicemia due to carrying of
bacteria into bloodstream
Dr.Sherif Elbadrawy

Rx of Strongyloides stercoralis ? thiabendazole, albendazole.
Ivermectin also used, particularly in
chronic infections.
Commonest cause of visceral larva
migrans ?
TOXOCARA CANIS
dt ingesting eggs from soil
contaminated by dog faeces
eye granulomas, liver/lung
involvement
Etiology of Cysticercosis ? Taenia solium (from pork) and
Taenia saginata (from beef).
Rx niclosamide
Rx of Cysticercosis ? niclosamide
Etiology of Hydatid disease ?
dog tapeworm Echinococcus
granulosus
Often seen in farmers
May cause liver cysts
Rx Albendazole
Dr.Sherif Elbadrawy

Rx of Hydatid disease ? Albendazole
The most common infecting
organism after a dog bite ?
Anaerobic mouth flora pasteurella
multocida
capnocytophaga & strept pyogenes may be
present
Commonest cause of viral
gastroenteritis ?
✬ Norwalk virus (norovirus) ➜Watery
diarrhea
✬ sporadic & epidemic diarrhea
✬ Dx by ELISA ➜ viral Ag detection
✬ (other viral causes of watery diarrhea
include Rotavirus and Adenovirus)
The rapid development of focal
neurological signs, in the context of
severe immunosuppression with HIV and
the
presence of multiple ring-enhancing
lesions in the brain ?
✬ toxoplasmosis
Tuberculosis, progressive multifocal
leucoencephalopathy (hyperintense signal on
T2-weighted images,cerebellar), lymphoma a
(solitary lesion) & HIV encephalopathy are
also possible diagnoses in the present case.
Definition of Tropical sprue ?
a malabsorption disease commonly found
in the tropical regions, marked with
abnormal flattening of the villi and
inflammation of the lining of the small
intestine.
Dr.Sherif Elbadrawy

pigment producing bacteria:
"ISRAEL has YELLOW SAND" ?
actinomyces israeli - yellow "sulfur"
granules
primary affect face & neck➜usually
present as abscess.
HIV-positive. Her CD4 count is > 200 and she
presented with salmonella gastroenteritis. Rx successfully.
In addition to (HAART), we should give prophylaxis
against which one of the following organisms ?
Toxoplasma gondii
Cytomegalovirus
Pneumocystis jiroveci
Salmonellae
Clyptococci
✬ SALMONELLAE
✬ prophylaxis for (P. jiroveci, cytomegalovirus, Toxopiasma and
cryptococcal infections) can be D/C in patients with CD4 > 200.
Long-term therapy ➜to prevent a recurrence in people diagnosed
with salmonellosis. ➜ despite HAART, patients infected with HIV
appear to mount an ineffective antibody response to salmonella
infection.
✬ Ciproﬂoxacin is usually the ﬁrst choice
Which one of the following options is true with respect to
prophylaxis against pneumococcal infection in post splenectomy
pt.?
☆ Penicillin is not indicated
☆ Penicillin prophylaxis 500 mg bd is indicated for at least a 2-
year period
☆ Penicillin prophylaxis 250 mg bd is indicated for a 2-year period
☆ They should be immediately revaccinated against pneumococcus
☆ Pneumococcal vaccination should be repeated every 10 years
☆ Penicillin prophylaxis 500 mg bd
is indicated for at least a 2-year
period !!
☆ Pneumococcal vaccination should
be repeated every 5 years
risk of developing various infections
and oppertunistic diseases at
different CD4 counts landmarks in
HIV infected patients ?
☆ CD4 count above 700 ➜Normal
☆ CD4 count 200-500 ➜ Oral thrush, Kaposi sarcoma,
TB, Zoster, and lymphoma
☆ CD4 count 100-200 ➜ PCP pneumonia, PML,
Dementia, Histoplasmosis, and Coccidiomycosis
☆ CD4 count 50-100 ➜ Toxoplasmosis, Cryptococcosis,
and Cryptosporodiosis
☆ CD4 count less than 50 ➜ CMV, Mycobacterium avium
complex, CNS lymphoma
characteristic diseases in AIDS
patients ?
☆ Hairy Leukoplakia
☆ Kaposi Sarcoma (CD Count: 200 - 500 cells/ml)
☆ High-grade B-Cell Lymphomas
☆ Cervical cancer
☆ Wasting syndrome
☆ Nephropathy
☆ Dementia (CD Count: 100 - 200 cells/ml)
Dr.Sherif Elbadrawy

AIDS Oppurtunistic Infections ?
✪ LUNG -
✷ PCP - pneumonia, also in bone marrow (CD100 - 200 )
✷ Mycobacterium TB - (CD : 200 - 500)
✷ Mycobacterium avium-intracellulare - also in GI tract (CD: <50)
✷ Coccidioidomycosis
✷ Histoplasmosis
✷ CMV - also affect retina, adrenals and GI tract (CD: <50)
✷ Cryptococcus
✪ Esophagus -
✷ HSV - also cause CNS encephalitis (CD : 200 - 500)
✷ Candida - oral thrush in oral pharynx (CD: 200 - 500)
✪ GI Tract -
✷ Giardia Lamblia
✷ Cryptosporidium
✪ CNS -
✷ Aspergillus - spores can also affect lungs and blood vessels
✷ Toxoplasmosis - MC opportunistic infection of brain (CD : <100)
✷ Cryptococcus -meningitis(most common presentation for cryptococcus "also in the lung") (chronic only, not acute) (CD
:<100 )
✷ JC virus - progressive multifocal leukoencephalopathy (CD: <50)
When should the patient in a pre splenectomy case
receive conjugate pneumococcal vaccination?
✬ 1 week before operation
✬ 5 days before operation
✬ 2 weeks before operation
✬ 1 month after operation
✬ Postoperatively
2 weeks before operation
also Hib & meningococal vaccine
A throat swab reveals diphtheria Which one of the
following options is the next most appropriate
action?
✬ Examine the cerebrospinal ﬂuid (CSF)
✬ Blood cultures
✬ Ceftriaxone
✬ Antitoxin
✬ Hydrocortisone
Antitoxin
Clinical picture of Herpes simplex
virus kerariris ?
- Herpes simplex virus (HSV) keratitis is
characterised by the acute onset of pain,
blurred vision, conjunctival injection and
DENDRITIC ULCERATION of the cornea
- HSV keratitis can cause corneal blindness
and its treatment is urgent
Which one of the following options is the
most common side-effect of pyrazinamide?
Hepatitic dysfunction
Hyperuricaemia
Colour vision changes
Dizziness
Neurotoxicity
Hepatitic dysfunction
Hyperuricaemia is a characteristic SE
but not the most common.
Dr.Sherif Elbadrawy

Clinical picture of chickenpox ?
highly contagious disease caused by primary infection
with varicella zoster virus (VZV)
prodrome of constitutional symptoms ➜ characteristic
vesicular rash all over the body and/or oral sores ➜ blister
stage, intense itching is usually present. Blisters may also
occur on the palms, soles, and genital area. ± oral cavity
& tonsil areas in the form of small ulcers which can be
painful or itchy or both
Can Interferon administration in the
acute phase of infection prevents the
development of the chronic hepatitis
B carrier state ?
【NO】
Interferon administration in the
acute phase of infection has not
shown any benifit.but it's effective in
the Rx of chronic hepatitis B.
Etiology of Yellow fever ?
ﬂavivirus, and can vary in severity from a
mild illness to the severe classical form.
present in TROPICAL areas➜ Africa and
South America ➜ transmitted to human
by mosquito.
Clinical picture of Yellow fever ?
⌘ Aedes mosquitos
⌘ incubation period = 2 - 14 days
⌘ severe ﬂu-like illness with fever up to 40 ± epigastric pain and
vomiting
⌘ Relative bradycardia
⌘ a recovery phase and the patient feels well for several days
⌘ severe fever again+ jaundiced, hepatomegaly, ➜ haematemesis,
bleeding gums ➜ DIC.
⌘ Councilman bodies (inclusion bodies) may be seen in the
hepatocytes
Rx of Yellow fever ? Supportive therapy only
Mortality up to 40%
Dr.Sherif Elbadrawy

Dx of malaria ?
❂ Three separate blood films should be sent to r/o
malaria when it is suspected.
❂ Thick & thin film blood smear ➜ film is +ve ➜
send the other blood samples.. if the pt is severely ill
or deteriorating ➜ start antimalarial Rx ASAP before
C&S result.
❂ Although the patient may use malaria prophylaxis,
they're still at risk of malaria infection
Clinical picture of Cerebral
toxoplasmosis in AIDS ?
❊ most common infection of the CNS in
AIDS when the CD4 < 200
❊ focal neurological disturbance,
headache, confusion, fever and
convulsions
Dx of Cerebral toxoplasmosis in
AIDS ?
Toxoplasma cysts in the brain➜
multiple ring-enhancing masses with
surrounding oedema
Rx of Cerebral toxoplasmosis in
AIDS ?
Pyrimethamine — an antimalarial
medication
Sulfadiazine — an antibiotic used in
combination with pyrimethamine to treat
toxoplasmosis
+ Folic acid
What Is the Difference between HIV
and AIDS?
When a person is infected with the human immunodeficiency virus
(HIV) we say that he or she is "HIV positive" .A person who has
HIV is classified as having AIDS if one of two things happens:
❊ if the CD4 count has dropped below 200/cc, or
❊ if an HIV-related infection or HIV-related cancer develops.
A patient may have 200 CD4 cells or less and feel very healthy, but
he or she still has AIDS by definition.
Dr.Sherif Elbadrawy

F Pt. returns from South Africa with confusion and
headache, no neck stiffness. She has a purpuric rash.
Malaria prophylaxis included mefloquine.most important
Ix ?
Lumbar puncture
Computed tomography (CT) scan
Multiple blood cultures
Malaria films
Clotting
Malaria films
Although the patient in the present
case has used malaria prophylaxis,
she is still at risk of malaria infection
Bacterial endocarditis is treated with penicillin. What
single additional step is undertaken to prevent penicillin
resistance?
Double the penicillin dose
Give a suitable B-lactam combination
Add macrolides
Add aminoglycosides
Interrupt penicillin treatment
Add aminoglycosides
Homosexual male with a lesion on his penis that was initially
nodular and painless➜ a heaped-up ulcer. Sampling ➜Biopsy:
large infected mononuclear cells
containing many Donovan bodies. What diagnosis fits best with
this clinical picture?
Penile carcinoma
Lymphogranuloma venereum
Chancroid
Genital herpes
Granuloma inguinaie
Granuloma inguinaie
Caused by➜ Klebsiella granulomatis
key features➜ painless indurated nodule➜heaped-
up ulcer + infected mononuclear cells containing
many Donovan bodies
Rx➜ tetracycline or ampicillin
25 y woman gives birth at full term to an otherwise well baby with
UNILATERAL MICROPHTHALMIA. She recalls a rash during the
first trimester of her pregnancy, but cannot remember any other
details of the rash. Which one of the following options is the most
likely causative agent?
☆ Syphilis
☆ Varicella zoster virus (VZV)
☆ Rubella
☆ Cytomegalovirus (CMV)
☆ Parvovirus B19
✱ Varicella zoster virus (VZV)
☆ The fetus develops episodes of shingles
that affect development of the involved
dermatome
☆ Congenital syphilis, CMV and rubella tend
to cause symmetrical problems
Etiology of mumps ? Paramyxovirus
Dr.Sherif Elbadrawy

Etiology of Q fever ?
Coxiella burnetii
obligate intracellular bacteria & doesn't grow
on standard culture media.
man infection by inhalation or drinking
unpasteurized milk.
Criteria of Mycobacterium avium
complex (MAC) infection ?
✬ opportunist mycobacterium found in soil, water, dust, milk
✬ usually attacks patients with pre-existing lung disease ➜ COPD ,
bronchiectasis or immunosuppressed
✬ Dx➜ X-ray ➜cavitation,sputum C&S
✬ Rx➜ rifampicin and ethambutol for 24 months ± lsoniazid .
✬ if Rx failure ➜ add Ciproﬂoxacin or clarithromycin
✬ surgical resection of the disease area is an option in fit pts.
Etiology of Paragonimiasis ?
Paragonimus westermani is in the genus of
flatworms,( an infectious lung fluke).
lower lobe cavitating lesions, an eosinophilia
A granulomatous response to the eggs may
occur
DD from TB ➜lack of systemic symptoms
(fever, weight loss),-ve acid-fast bacilli
most common cause of failure of
antiretroviral Rx ?
Poor compliance to Rx.
Human T-cell lymphotrophic virus
type I is associated with which type of
cancer ?
acute T-cell lymphoma/leukaemia
Dr.Sherif Elbadrawy

Human papilloma virus is associated
with which type of cancer ?
carcinoma of anal canal in
homosexual men
A 7-y boy who has come from lndia ➜ mild fever (37.5 °C),
maculopapular rash and pharyngitis. difﬁculty swallowing, even
his own saliva+ greyish membrane surrounding the tonsils+
regional lymphadenopathy. most likely diagnosis?
◆ Infectious mononucleosis
◆ Diphtheria
◆ Rubella
◆ Measles
◆ Streptococcus pyogenes
◆ Diphtheria
Which one of the following antigens is involved in
the entry of Plasmodium vivax into red cells?
Anti-D
Anti-S
Duffy
Kell
Kidd
Duffy
Constipation, mucopurulent anal
discharge, perianal pruritis and anal
bleeding and pain while opening
bowels in homosexual man ?
Think of Gonorrhoea (Smear reveals
intracellular diplococci).
Risk of vertical transmission in Fully
controlled HIV ?
perinatal transmission<1% and most
likelihood of transmission is
during delivery (risk minimized by
intrapartum zidovudine and 6 weeks
after birth to baby).
Dr.Sherif Elbadrawy

Clinical picture of Tapeworm
infection ?
✼ Tape worms are made up of repeated segments
called proglottids (actively motile, elongating and
contracting)
✼ often present in faeces and are useful diagnostically
✼ Taenia solium (pork tapeworm) and Taenia
saginata (beef tapeworm) infection『Cysticercosis』
✼ niclosamide or praziquantel.
The larvae of which one of the following helminth species
undertakes a symptomatic travel through
the LUNG before the adult worms reside in the intestine?
Enterobfus vermfcularfs
Trfchfnella spfralfs
Ascaris lumbricoides
Trfchurfs trfchurfa
Taenfa sagfnat
Ascaris lumbricoides
Rx of choice for cryptococcus
neoformans ?
Amphotrecin B
Definition of Multidrug-resistant
tuberculosis ?
✪ resistance to rifampicin and isoniazid,
with or without resistance to other anti-TB
drugs.
✪ Rx at least 3 drugs to which the organism
is sensitive in-vitro for at least 9 months and
perhaps up to or beyond 24 months
Rx of Multidrug-resistant
tuberculosis ?
✪ has to be planned on an individual basis
✪ should only be carried out by physicians with
substantial experience in managing complex resistant
cases
✪ at least 3 drugs to which the organism is sensitive
in-vitro for at least 9 months and perhaps up to or
beyond 24 months
Dr.Sherif Elbadrawy

percentages of untreated pts that will develop late
stages CNS & CVS complications ?
80%
90%
10%
30%
0%
30%
Difference Dengue and Malaria Fever
?
✷ Both spread by MOSQUITOES. Malaria is dt a parasite plasmodium whereas dengue is dt a
flavivirus (Dengue virus)
✷ Dengue is the fever é sudden onset and remains for long duration. It is reaches to the
temperature level of ≅ 40 ℃
✷ SEVERE HEADACHE mostly in the back portion of the eyes head is CHARACTERISTIC FOR
DENGUE.
✷ The dengue fever may disappear after the few days but sudden rise again with the problem of
SKIN RASHES (rash of Dengue isn't dependant on thrombocytopenia)(similar to measles)
✷ in malaria, fever is for shorter period. The symptoms of malaria are anemia, pain in the joints,
vomiting, sweating etc. There are 3 stages for the malaria symptoms. They are Cold stage,
Sweating stage and the last is again cold stage.
✷ Incubation period 10-15 days for malaria & 4-5 days for dengue.
in Dengue Lymphocytosis is seen although the total WBCs may be normal.
Selective serotonin reuptake inhibitor
(SSRI) withdrawal ?
SSRI withdrawal appears to be a particular
problem with paroxetine, which can lead to
symptoms of psychomotor agitation, poor
sleep and anxiety, vertigo and light
headedness. ± GIT symptoms.
avoided by slow tapering down the drug.
Dx of Schistosoma Hematobium ? a mid-day urine sample ➜ look for
the parasite
Clinical picture of Acute
schistosomiasis (Katayama's fever) ?
may occur weeks after the initial infection, especially by S.
mansoni and S. japonicum. Manifestations include:
Abdominal pain
Cough
Diarrhea
↟ Eosinophilia
Fever
Fatigue
Hepatosplenomegaly
Dr.Sherif Elbadrawy

Elderly + orbital cellulitis +maxillary
sinusitis + C&S ➜ irregularly
branching septate hyphae ,Dx ?
Aspergillus
Clinical picture of Mucor mycosis ?
DM is the ppt factor.
Rhinocerebral Mucor mycosis is the most
common form.
necrotic black nasal turbinate, nasal
stufiness,facial pain & edema are
characteristic.
35 sailor ,painless swelling in the
sole of his foot , increase in
size,ulceration + yellow, white grains
on the surface Gm stain ➜Gm +ve
branching organism
Nocardia brasiliens
Mucocutaneous ulceration following
travel?
Leishmania brasiliensis
Start anti-retrovirals in HIV when
CD4
< 350
Dr.Sherif Elbadrawy

Management of contacts of
meningococcal meningitis
ciprofloxacin is the drug of choice as
it is widely available and only
requires one dose, rifampicin may be
used
Management of contacts of
pneumococcal meninigitis
no prophylaxis is generally needed
Management of Meningococcal
Meningitis
pre-hospital (for example a GP surgery) and
meningococcal disease is suspected then
intramuscular benzylpenicillin , as long as
this doesn't delay transit to hospital ➜ If
immediate hypersensitivity reaction to
penicillin or to cephalosporins ➜ Give
Chloramphenicol.
Rx of Cellulitis
✯ Penicillin is the antibiotic of choice for group A streptococcal
infections.
✯ flucloxacillin is first-line treatment for mild/moderate cellulitis. [ stop
flucloxacillin if streptococcal infection is confirmed in patients with
cellulitis, dt the high sensitivity & change it with Penicillin]
✯ Clarithromycin or clindamycin is recommend in patients allergic to
penicillin.
Brucellosis
✯ > in Middle East and in farmers
✯ fever, malaise
✯ leukopenia
✯ hepatosplenomegaly
✯ sacroilitis: spinal tenderness
✯ osteomyelitis, infective endocarditis, orchitis,
meningoencephalitis
✯ screening ➜ Rose Bengal plate test
✯ Brucella serology is the best test for diagnosis
✯ Rx ➜ doxycycline and streptomycin
Dr.Sherif Elbadrawy

Organisms which may colonise CF
patients
✯ Staphylococcus aureus
✯ Pseudomonas aeruginosa
✯ Burkholderia cepacia ➜
Pseudomonas cepacia
✯ Aspergillus
Bacteriostatic antibiotics
✯ chloramphenicol
✯ macrolides
✯ tetracyclines
✯ sulphonamides
✯ trimethoprim
Epididymo-orchitis
✯ infection of the epididymis ± testes ➜ pain and
swelling
✯ dt local spread of infections from the genital tract
(Chlamydia trachomatis and Neisseria gonorrhoeae) or
the bladder.
✯ U/L testicular pain and swelling ±urethral discharge
✯ DD is testicular torsion ➜ Pt < 20 years, severe pain
and acute onset
✯ Rx ➜ IM ceftriaxone stat + oral doxycyline for 2 weeks
HIV drugs, rule of thumb: NRTIs end in 'ine'
Pis: end in 'vir'
NNRTIs: nevirapine, efavirenz
Dr.Sherif Elbadrawy

MRCP Infectious disease notes.

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MRCP Infectious disease notes.