Communicable Diseases Epidemiology

Dr. Mohamed Hassan Nour
East Africa UniversityEast Africa University
Communicable diseasesCommunicable diseases
Dr. Mohamed Hassan

What are communicableWhat are communicable
diseases?diseases?
Communicable diseases refer to the
diseases that can be transmitted and
make people ill. They are caused by
infective agents (pathogens) that
invade human body or release toxins
to cause damages to normal body
cells and their functions. In severe
cases, they may lead to death.

Definition of EpidemiologyDefinition of Epidemiology
Epidemiology is the study of the
distribution and determinants of
health-related states and events
in populations, and the
application of this study to
control health problems

Importance of StudyingImportance of Studying
Communicable DiseasesCommunicable Diseases
EpidemiologyEpidemiology
Changes of the pattern of infectious
diseases
Discovery of new infections
The possibility that some chronic
diseases have an infective origin.

Critical world healthCritical world health
problemsproblems
 Critical world health problems still
exist and include:
1. Communicable diseases such as
tuberculosis, measles, mumps,
rubella, and polio.
2. Maternal and Child Health
3. Diarrheal diseases
4. Nutritional deficits
5. Malaria Dr. Mohamed Hassan Nour

Infectious Disease ModelInfectious Disease Model
Host
Pathogen
Environment
disease

Nursing ResponsibilitiesNursing Responsibilities
Assessment:
Identify recent exposure
Identify prodromal symptoms
–s/s occur early in disease
Locate immunization history
Confirm history of having the
disease

ImplementationImplementation
 prevent spread-isolation
 reduce risk of cross
contamination
 prevent complications
 provide comfort

Routes of transmissionRoutes of transmission
• Direct
 Skin-skin
 Herpes type 1
 Mucous-mucous
 STI
 Across placenta
 toxoplasmosis
 Through breast
milk
 HIV
 Sneeze-cough
 Influenza
• Indirect
 Food-borne
 Salmonella
 Water-borne
 Hepatitis A
 Vector-borne
 Malaria
 Air-borne
 Chickenpox

Dr. Mohamed Hassan NourDr. Mohamed Hassan Nour
No. Infectious agents Diseases
1. Viruses Common cold, Influenza, Measles, Mumps,
Chicken pox, AIDS, Hepatits-B etc.
2. Bacteria Cholera, Typhoid, Tuberculosis, Tetanus,
Anthrax, Food poisoning etc.
3. Fungi Skin infections.
4. Protozoans Malaria, Kala-azar, Amoebic dysentry,
Sleeping sickness.
5. Worms Intestinal infections, Elephantiasis.

Chicken poxChicken pox
Chicken pox is a common disease
caused by the varicella zoster virus
(VZV) which is a member of the
herpes virus family.
Usually occurs during childhood, but
you can get it at any time in your
life.

Symptoms:Symptoms:
 Fever
 Body aches
 loss of appetite.
Within 1or 2 day, the rash appears,
begins as red spots which then form
blisters and spreads to the rest of
the body.

Chicken boxChicken box

PreventionPrevention
There are no actual cures for it ,but
you can get a vaccine shot to help
prevent it.
Antiviral drugs such as Acyclovir may
be prescribed
Also you can give pain relief such as
parecatamol
If very dehydrated correct the
dehydration

ComplicationsComplications
Encephalitis
A) cerebellar involvement with ataxia
is the most common form , the
prognosis is good
B) cerebral involvement in the form of
meningoencephalitis may occur.
clinical picture: fever , headache, stiff
neck disturbed consciousness ,
convulsions , coma , and paralysis

Cont……Cont……
Heart
 pericarditis
 mycorditis
 endocarditis
Respiratory
 laryngitis
 varicella pneumonia
 Eye keratitisDr. Mohamed Hassan Nour

DiphtheriaDiphtheria
It is caused by bacteria
Corynebacterium diphtheriae
Symptoms
 Sore throat
 Low fever
 Bull neck appearance due to
enlarged cervical nodes
 Airway obstruction and breathing
difficulty
 Shock. Dr. Mohamed Hassan Nour

Contin……..Contin……..
 Airway obstruction and breathing
difficulty
 Shock
 Red throat
 Grey pharyngeal membrane

Cont….Cont….
Modes of Transmission:
spread by
 droplets
 Secretions
 Direct contact
 Poor nutrition
 Low vaccine coverage among infants
children.

Reduce carrier rate by use of
vaccine.
Immunological: A vaccine (DPT)
Chemotherapeutic
 Penicillin
 Erythromycin or
 Gentamicin are drugs of choice.

DiphtheriaDiphtheria

FFilariasisilariasis
Infection caused by 3 closely related
Nematodes-
 “Wuchereria bancrofti”
 “Brugia malayi”
 “Brugia timori

Cont….Cont….
Symptoms
 Filarial fever
 Lymphangitis
 Lymphadenitis
 Elephantiasis of genitals/legs/arm,
 Filarial arthritis
 Chyluria.

Contin…….Contin…….
Mode of transmission
Transmitted by the bite of infected
mosquito responsible for
considerable sufferings

Treating the infection by Cooling the
leg, drying, exersice.
Treatment and prevention of
Lymphoedema.
Drugs effective against filarial
parasites-
1.Diethyl Carbamazine citrate (DEC)
2.Ivermectin
3.Albendazole
4.Coumarins compound

AIDSAIDS
Acquired Immunodeficiency
Syndrome”
 HIV (Human immunodeficiency
virus) is the virus that causes AIDS
 Disease limits the body’s ability to
fight infection due to markedly
reduced helper T cells.
Patients have a very weak immune
system (defense mechanism)

SymptomsSymptoms
Fever
 Headache
 Neuropathy
 Sores
 Rashes
Nausea
Vomitting.

Cont…Cont…
Mode of Transmission:
 Sharing Needles
 Unsterilized blades,
 Unprotected Intercourse,
 Mother to Baby
 Fluids ex. Blood transfusion

Protected Sex
 Sterile needles
New shaving/cutting blades
Avoiding any fluid that can lead to
risk
Anti-retroviral drugs are used-
 AZT (Zidovudine).
 Viramune (Nevirapine).
 Norvir (Ritonavir).Dr. Mohamed Hassan Nour

MeaselesMeaseles
Etiology measles virus (rubeolla): RNA
virus
Mode of infection: transmitted by droplet
and contact with articles freshly soiled by
nose and throat secretions of an infected
person in the prodromal phase
Period of infectivity: the patients are
contagious for at least seven days after
the onset of the first symptoms
Incubation period : 7-14days (ussually ten
days) Dr. Mohamed Hassan Nour

Cont….Cont….
Symptoms
 Diarrhea
 Pneumonia
 Convulsions, SSPE (sub acute
sclerosing panencephalitis)
 Fever
 Rash
 Conjunctives
 Kopliks spots

MeaslesMeasles

Laboratory findingsLaboratory findings
Leucopenia ( decreased number of
white cells)
 leucocytosis , if secondry bacterial
infections occurs
Prevention
Live attenuated measles virus
Measles vaccine has to be given at 9
months

TreatmentTreatment
General
isolation of the patient for one week from
the onset of the rash
Rest until a febrile and antipyretics as
salicylates for fever
Cough depressants ( codeine) for irritant
cough
Give metronidazole if oral ulcer
Give Vitamin A
If secondary bacterial infection give
antibiotis Dr. Mohamed Hassan Nour

TuberculosisTuberculosis
Tuberculosis is defined as an
infectious disease caused by a
bacterium Mycobacterium T.B. ; that
most commonly affects he lungs.
Symptoms
 Slight fever
 Night sweats
 Weight loss fatigue
 Caugh with productive.

ContinousContinous
Modes of transmission: tuberculosis
is an airborne disease able to be
passed from one person to another.

Prevention & TxPrevention & Tx
Avoid with active TB patients
If you contract TB of the abdominal
or of the extra- pulmonary you may
have the choice of a mainstay
therapy that takes a course of 9-12
months in order to complete.
Surgery is generally reserved for
patients with obstruction of vital
organs.

Cont….Cont….
The medication of T.B include
 Isonized
 Rifamicin
 Ethambutol
 Pyrazinamide
 Strepomycin

TetanusTetanus
A Neurological disease characterised
by increased muscle tone & spasms
Caused by CLOSTRIDIUM TETANI.
It is found worldwide in soil, in inanimate
environment, in animal faeces &
occasionally human faeces.

Symptoms
 Muscle rigidity
 Dysphagia
 Rigidity
 Spasm
 Hyperpyrexia.
Mode of transmission: Infection is
acquired by contamination of wounds with
tetanus spores.

Goal is to eliminate the source of
toxin
prevent muscle spasm & providing
support
Admit in a quiet room in ICU
Continuous careful observation &
cardiopulmonary monitoring
Protect airway
toxoid tetanus vaccine

RabiesRabies
Rabies is a viral disease that causes
acute encephalitis in warm blooded
animals, it can be transmitted to
humans from other species.
The rabies virus infects the CNS,
cause disease in brain & death.
If bitten by an animal, washing the
wound with soap and water for 10 to
15 minutes and contacting a
healthcare provider

SSymptomsymptoms
Partialparalysis
Anxiety
Insomnia
confusion
Agitation
 Abnormalbehavior,
Terror
Hallucinations
Prevention by
avoiding infected
animals or Not
handling wild
animals

MalariaMalaria
It is caused by four Plasmodium
species
P. falciparum
P. vivax
P. malariae
P. ovale
Symptoms
 Chills
 Fever
 Internal fever
 Body ache.

Cont…..Cont…..
Mode of transmission: It is
transmitted by female anopheles
mosquito, sporozoites injected with
saliva & enter circulation then
infected person.

Life cycle of malaria parasiteLife cycle of malaria parasite
 sporozoites injected
during mosquito feeding.
 invade liver cells.
 merozoites invade RBCs.
 gametocytes infective
for mosquito.
 fusion of gametes in
gut.
 sporozoites invade
salivary glands.

Using mosquito net
Using spray for insect killer
Cleaning water area
Malaria prophylaxis are taken

Erythema infectiousumErythema infectiousum
Fifth’s DiseaseFifth’s Disease
Etiology : it is viral disease caused
by parvovirus B19
It is transmitted by droplet
infection ; incubation periods :7-14
days

SymptomsSymptoms
Rash of erythema on
face (cheeks),
“slapped face
appearance

Cont…Cont…
After 4 days , the previous rash
disappears and another
maculopapular rash first appears on
the shoulder and extensors surface
of the extremities . In 3 days , it
extends to involve the flexor surface
and the trunk.

Cont…..Cont…..
The rash gives a typical lacelike
pattern of geographic lines . The
palms and soles are rarely involved .
average 10-12 days and has a
tendency to recur with exercise
warms baths , rubbing of the skin ,
exposure to sunlight or the extremes
of heat and cold.

Lace pattern of fifth diseaseLace pattern of fifth disease

Arthritis , aplastic crises in patient
with chronic hemolytic anemias as
sickle cell anemias and
encephalopathy( rare)
laboratory findings: WBCs count is
normal
Treatment : none specific
intravenous
immunoglobulins(IVIG) , for episodes
of anemia and bone marrow failure
in immunocompromisedDr. Mohamed Hassan Nour

Roseala infantum(exanthemRoseala infantum(exanthem
subitum)subitum)
Etiology : human herpes virus (6)
Incubation periods: 1-2 weeks
The clinical picture
age : mostly in infancy : but can
occur in any age

SymptomsSymptoms
 High fever
Malaise
Irritability
Convulsions
However , the
infant does not
look ill despite of
high temperature
Then drop in fever
to normal => rash
appears
rose-pink macules
first on trunk,
spread to neck,
face, extremities,
not itchy, lasts 1-2
days

ManagementManagement
antipyretics, analgesics, isolation not
necessary
Follow up for vital sings and checking
regulary.

PPertussisertussis
(Whooping cough)(Whooping cough)
Bacterial infection
Vaccine available
Transmitted by direct contact,
droplet
Communicable for up to 4 weeks

SymptomsSymptoms
Dry
Hacking cough that becomes severe,
worse at night
Eyes bulge
 Tongue protrudes
Vomits
Sick for 4-6 weeks

TxTx
Admit to the hospital the patient
Check for dehydration status
Give fluid if dehydrated
Monitor for airway
Monitor vital signs regulary
Follow up.

Sexually transmittedSexually transmitted
diseasedisease
STDs are diseases and infections which
are capable of being spread from person
to person through:
– sexual intercourse
– oral-genital contact or in non-sexual
ways.
– IV drug

Cont…..Cont…..
Some STD’s are:
 Chlamydia
 Gonorrhea
 Genital Herpes
 Syphilis
 HIV/AIDS

ChlamydiaChlamydia
A group of infections that attack the
reproductive system
Most common type of STD in the US
Symptoms : often there are no
symptoms, however, sometimes
there will be pain and an unusual
liquid coming from the penis or
vagina

Cont…Cont…
If detected, it can be cured with
antibiotics
If undetected, it can lead to damage
to the reproductive organs

GonorrheaGonorrhea
An STD caused by bacteria that live
in warm, moist body areas
Symptoms include a burning feeling
during urination and an unusual
liquid coming from the penis or
vagina

Cont…Cont…
• If treated, it can be cured with the
use of antibiotics

Herpes simplex virusHerpes simplex virus
HSV are large DNA virus of 2 types:
Modes of transmission:
 Skin to skin contact
 Mucous
 Saliva
Type I found in the oral and type II
found in genital area .

Cont….Cont….
Incubation periods 2-21 days
Clinical manifestation: primary
herpes: as
 Acute herpetic gingivostomatitis
 Skin and mucous mebrane :
dessiminated vesicles e.g in neonates
 Occular lesions e.g
keratoconjunctivitis
 Reccurent genital herpes

Secondary (or reccurent)Secondary (or reccurent)
herpesherpes
Reccurent stomatitis (cold sores)
 Reccurent papulovesicular rash
 Reccurent herpetic
keratoconjunctivitis
 Reccurent genital herpes

AcuteAcute
gingivostomatitisgingivostomatitis
Herpetic
keratoconjunctiva
Cold sores in a child

TreatmentTreatment
No treatment
Acyclovir is used in neonatal
infection, encephalitis, genital herpes
and occular lessions

Abstinence
Know your partner
Limit your partners
Visit your doctor
Always look
Keep clean

PoliomyelitisPoliomyelitis
Poliomyelitis is a highly infectious
disease caused by three serotypes of
poliovirus.
Symptoms
 Febrile illness
 Aseptic meningitis
 Paralytic disease
 death

Cont….Cont….
Modes of Transmission:
 Oral-oral infection
- direct droplet infection
 Faeco-oral infection
– Food-borne (ingestion)
– Hand to mouth infection

General prevention:
 Health promotion through
environmental sanitation.
 Health education (modes of spread,
protective value of vaccination).

Scarlet feverScarlet fever
Bacterial infection (strep), often
sequela to strep throat
No vaccine available
Transmission by direct contact,
droplet
Communicable for 10 days to 2
weeks

The symptoms
 Fever
 Vomiting
 Sore throat in the first 24 hours.
 Febrile convulsions may occur in
young children
 Exudative tonsilitis
 Exanthem ( rash )

Cont……Cont……
 White strawberry tongue
 desquamate in plaques esp. in
the hands and feet.
 red strawberry tongue

Conti…….Conti…….
Red strawberry tongue
White strawberry tongue
Desquamation of
the hand

Labarotary findingsLabarotary findings
 Leucocytosis
Antistreptolysin O (ASOT) titre more
than 250todds units( in the second
week )
Positive throat culture for the
organism

Immediate complications :
Otitis media , adenitis esp . Cervical
Laryngitis ,
laryngotracheobronchitis , empyema
Metastatic infection as :
meningitis , arthritis, osteomyolitis,
pericarditis ,septicemia

Delayed complicationsDelayed complications
Acute glemorunephritis
Rheumatic fever in susciptle

TreatmentTreatment
General : antipyretics
Specific: procaine penicillin is the
drug of choice , its given I.M 400000
IU per day , for ten days .
If the patient is sensitive to penicillin
, erthromycin can be used
( 40mg/kg/day)
Orally in four divided doses for ten
days

Hand-foot andHand-foot and
mouth Diseasemouth Disease
Is an acute self-limiting contagious
viral infection transmitted from one
individual to another. Caused by
Coxsackie virus Group A.
Mucosa, tongue, and labial mucosa
are the most commonly affected
sites.

Conti…..Conti…..
Age: Children and young adults.
 Clinical Features:
 Oral manifestations are always
present, and are characterized by
small vesicles (5–30 in number) that
rapidly rupture, leaving painful,
shallow ulcers (2–6 mm in diameter)
surrounded by a red halo.

Cont…..Cont…..
The buccal mucosa, tongue, and
labial mucosa are the most
commonly affected sites.
Skin lesions are not constant, and
present as small vesicles with a
narrow red halo. The lateral borders
and the dorsal surfaces of the fingers
and toes are the most common areas
involved.

Conti…Conti…
Lesions may appear on the palms,
soles, and buttocks. The disease
lasts five to eight days. The
diagnosis is made on the basis of
clinical criteria
 Management: Supportive.

Communicable Diseases Epidemiology

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