systemic change due to viral infection

1. VIRAL INFECTIONS ON SKIN,
RESPIRATORY,
GASTROINTESTINAL, OTHERS.

2. Viral infections of the skin:

3. 1= Herpes simplex virus 1 and 2
• Herpes simplex viruses (HSVs) cause recurrent
mucocutaneous infection.
• HSV-1 typically involves the mucocutaneous surfaces of the
head and neck.
• HSV-2 predominantly involves the genital mucosa.
• Clinical features:
 Initally: Fever and regional lymphadenopathy.
 Gingivostomatitis, pharyngitis.
 Recurrent HSV genital disease is a common cause of
recurrent painful ulceration.
• Recurrent attacks occur throughout life.
• Oral lesion “herpes labialis”.
• lesion on the finger “Herpetic whitlow”.

5. • Complications:
A. Skin: eczema (eczema herpeticum).
B. Eye: Herpes keratitis (pain and blurring of vision, corneal
scarring and permanent visual impairment).
C. Nervous: meningitis or transverse myelitis, encephalitis,
temporal lobe epilepsy and altered consciousness/coma.
D. Neonatal: cutaneous lesions, hepatitis, pneumonitis and
frequently encephalitis.
E. Immunocompromised hosts: oesophagitis, hepatitis,
pneumonitis, encephalitis or retinitis.
• Diagnosis:
• Vesicular fluids - Direct immunofluorescence or PCR.
• CSF - HSV encephalitis by a positive PCR.
• Management:
• Oral lesions - topical aciclovir.
• HSV encephalopathy - Aciclovir if resistance [foscarnet].

6. 2= Human herpesvirus 8
• Human herpesvirus 8 (HHV-8) causes Kaposi’s sarcoma in
both AIDS-related and non-AIDS-related forms.
• HHV-8 is spread via saliva, and men – men intercourse.
• Highest in sub-Saharan Africa.
• HHV-8 also causes two rare haematological malignancies:
1. Primary effusion lymphoma.
2. Multicentric Castleman’s disease (a condition resembling
lymphoma but without recognizable malignant cells
usually seen in abdominal or mediastinal).
• Current antivirals are not effective.

7. 3= Enterovirus infections
• Systemic infection is caused by Coxsackie viruses
usually, or occasionally by Echoviruses.
• It affects children and occasionally adults, resulting in
local or household outbreaks.
• Incubation period of 10 days.
• Clinical features:
• Fever and lymphadenopathy during incubation
period.
• 2–3 days later:
• Painful papular or vesicular rash appears on
palmoplantar surfaces of hands and feet.
• Oral lesions on the buccal mucosa and tongue that
ulcerate rapidly.

8. • A papular erythematous rash on buttocks and
thighs.
• Management:
• Symptom relief with analgesics.

9. 4= Poxviruses:
• These DNA viruses are rare but potentially
important pathogens.
• Smallpox (variola).
• Monkeypox.
• Cowpox.
• Others: orf and molluscum contagiosum.

10. A) Smallpox (variola):
• High mortality, was eradicated worldwide
• Spread by the respiratory route or contact with
lesions, and is highly infectious.
• The incubation period is 7–17 days.
• Clinical feature:
• A prodrome with fever, headache.
• Rash on the face and distal extremities (macules and
papules to vesicles and pustules).
• National public health authorities must be
contacted.
• Electron micrography and DNA detection tests (PCR).

11. B) Monkeypox:
• Caused by small squirrels and rodents.
• Central Africa.
• Vesicular rash + lymphadenopathy.
• Little person-to-person transmission occurs.
• Diagnosis :
• Electron micrography or DNA detection (PCR).

12. C) Cowpox:
• Humans in contact with infected cows.
• Fever and regional lymphadenitis.
• Large vesicles on the hands or arms and
associated.

13. • Molluscum contagiosum is caused by a DNA poxvirus
• It is most common in children over the age of 1 year,
particularly those with atopic dermatitis. It also occurs frequently
in immunosuppressed patients, including those with HIV (p. 306).
• Clinical feature:
• Lesions are dome-shaped, ‘umbilicated’, skin-coloured papules
with central punctum (Fig. 29.25). They are often multiple and
found at sites of apposition, such as the side of the chest and
the inner arm. Spontaneous resolution occurs but can take
months. Prior to resolution, they often become inflamed and
may leave small, atrophic scars. Destructive therapies may
be painful and risk scarring, and the decision not to treat is
often sensible. Gentle squeezing with forceps after bathing can
hasten resolution. Topical salicylic acid, podophyllin, cantharidin,
trichloroacetic acid, cryotherapy and curettage are alternatives.
Efficacy with imiquimod has also been reported
C) Molluscum contagiosum:

15. Gastrointestinal viral infections

16. 1= Norovirus (Norwalk agent)
• Outbreaks in hospital wards, cruise ships and military
camps.
• Food handlers, relatively resistant to decontamination
procedures.
• The incubation period is 24–48 hours.
• Clinical feature:
• Prominent vomiting and Gastroenteritis.
• Diagnosis:
• Electron microscopy.
• Antigen or DNA detection (PCR) in stool samples.
• Management:
1. Patient isolation.
2. Cleaning environmental surfaces with detergents and
disinfected with bleach.

17. 2= Rotavirus
• Occurs in young children worldwide.
• Winter epidemics in developed countries, particularly in
nurseries.
• Rotaviruses infect enterocytes.
• Incubation period is 48 hours.
• Clinical feature:
1. Watery diarrhoea, vomiting, fever and abdominal pain.
2. Prominent dehydration.
• Diagnosis:
• Enzyme immunoassay kits which require fresh or
refrigerated stool samples.
• Vaccination Monovalent and multivalent.

18. Respiratory viral infections

19. • Multiple viral diseases causes upper & lower
respiratory diseases:
• Adenoviruses, rhinoviruses and enteroviruses
(Coxsackie viruses and echoviruses):
Often produce non-specific upper respiratory tract
symptoms but may cause viral pneumonia.
• Parainfluenza and respiratory syncytial viruses:
Cause upper respiratory tract disease, croup and
bronchiolitis in small children and pneumonia in the
immunocompromised & nursing home.
• Metapneumovirus and bocavirus:
Cause upper and occasionally lower respiratory tract
infection.

20. 1= Middle East respiratory syndrome
coronavirus (MERS-CoV)
• In 2012, a several deaths connected with
pneumonia are caused by novel coronavirus & SARS
(severe acute respiratory syndrome) coronavirus.
• History of travel to Saudi Arabia.
• Zoonosis [bats to camels and then to humans].
• Person-to-person transmission.
• Incubation period 2–14 days.
• Clinical features:
• Fever, chills, headache, myalgia, dry cough and
dyspnoea.
• Abdominal pain and diarrhoea may be prominent.

21. • Complication:
• ARDS and multi-organ failure.
• Diagnosis:
o Lymphopenia, thrombocytopenia and raised lactate
dehydrogenase (LDH).
o PCR of serum.
o Nasopharyngeal or other respiratory samples.
• Management:
• Supportive.
• Patients should be managed in an airborne infection
isolation room.
• Health-care workers should wear protective
equipment.

22. Viral infections with
neurological involvement

23. 1= Japanese B encephalitis
• This flavivirus, are endemic in Japan, China, Russia, South-
east Asia, India and Pakistan;
• Pigs and aquatic birds reservior, and transmission is by
mosquitoes.
• Exposure to rice paddies is a recognised risk factor.
• Incubation period is 4–21 days.
• Clinical features:
• Subclinical.
• Fever, malaise and anorexia is followed by headache,
photophobia, vomiting and changes in brainstem function.
• Meningism, seizures, cranial nerve palsies, flaccid or spastic
paralysis and extrapyramidal syndromes.

24. • Diagnosis:
• Neutrophilia, hyponatraemia.
• CSF - lymphocytosis and elevated protein.
• Management and Prevention:
• Treatment is supportive.
• Vaccination is recommended for travellers to
endemic areas during the monsoon.
• Some endemic countries include vaccination in
their childhood schedules.

25. 2= West Nile virus
• This flavivirus cause disease in Australia, India and
Russia through Africa and Southern Europe and
across to North America.
• Avian reservoir and a mosquito vector.
• Older people are at increased risk of neurological
disease.
• Incubation period 2-6 days.
• Clinical features:
• Asymptomatic.
• Mild febrile illness and arthralgia.
• Children may develop a maculopapular rash.
• Neurological disease encephalitis, meningitis or
asymmetric flaccid paralysis.

26. • Diagnosis:
• Detection of viral RNA in blood or CSF.
• Serological tests may show cross-reactivity with
other flaviviruses.
• Management:
• is supportive.

27. 3= Enterovirus 71:
• Globe of enteroviral disease with hand, foot and
mouth disease aseptic meningitis.
• Complication:
• Encephalitis with flaccid paralysis or by
brainstem involvement and death.
• Diagnosis:
• Vesicle fluid, stool or CSF, and viral RNA can be
detected in CSF by RT-PCR.

28. 4= Human T-cell lymphotropic virus
type I (HTLV-1):
• Chronic infection with development of adult T-cell
leukaemia/lymphoma (ATL) or HTLV-1-associated
myelopathy (HAM).
• Japan, the Caribbean, Central and South America, and the
Seychelles.
• Clinical feature:
A. HAM infection: spastic paraparesis with gait disturbance,
spasticity of the lower extremities, urinary incontinence,
impotence and sensory disturbance.
B. HTLV-1 infection: Myositis and uveitis.
• Diagnosis: PCR.
• Management: is usually supportive.

29. Rheumatological viral infection:

30. • Variety of viral infections causes
rheumatological disease (rubella, parvovirus
B19, Hepatitis B Virus, HIV-1, Ebola virus
disease.

31. 1= Chikungunya virus:
• Chikungunya is an alphavirus.
• Africa and Asia, vector Aedes aegypti mosquito.
• Incubation period is 2–12 days.
• Clinical feature:
• Fever and rash.
• Arthritis in adults.
• Management:
• symptomatic.