COVID-19 INFECTION

Despite the lesser incidence and severity, SARS- CoV-2 (COVID-19) infection in children posed unique challenges during the pandemic due to large pool of asymptomatic cases to facilitate spread of infection, different modes of presentation, e.g.

Children lt;19 years of age contributed to ~10% of reported COVID-19 cases but with lt;5% of hospitalizations and lt;0.5% of mortality, globally as well as in India.

Infectious mononucleosis is a clinical illness characte­rized by acute fever, sore throat and generalized lympha­denopathy, along with presence of atypical lymphocytes in blood. Over 90% cases are caused by Epstein-Barr virus (EBV). Remaining may be due to other viruses, e.g. CMV, adenovirus, rubella, HIV, etc. or parasites, e.g. toxoplasma.

Epidemiology: EBV is intermittently excreted in oro­pharyngeal secretions of the infected person (reservoir) and transmitted by close contact, e.g. kissing. Primary infection is common in children lt;3 years and usually remains dormant except intermittent viral shedding throughout life. Clinical disease denotes either primary infection or reactivation of latent infection.

On entry, EBV replicates in oral epithelial cells and salivary glands, followed by viremia with disseminated infection of B-lymphocytes and lymphoreticular system. Characteristic atypical lymphocytes in these cases are actually CD₈ lymphocytes, formed to prevent the spread of infected B-cells. Infection persists life-long in oropharyngeal cells and B-cells, to re-activate any time, specially in immunocompromised states.

Clinically EBV infection is mostly asymptomatic, though symptomatic disease, i.e. infectious mononucleosis presents after an incubation period of 4-6 weeks, with:

• Prodromal phase with mild fever, malaise, headache, myalgia, sore throat and abdominal pain for 1-2 weeks.

[****] Characteristic phase with—(i) progressively rising fever, (ii) sore throat, (iii) generalized lymphadenopathy (90%), (iv) splenohepatomegaly, and (v) maculopapular rash (5-15%). Epitrochlear lymphadenopathy and development of rash on ampicillin therapy are useful indicators of infectious mononucleosis.

12.3.3