Pneumococcal serotypes associated with invasive disease in under five children in India & implications for vaccine policy

Background & objectives: Streptococcus pneumoniae is a major cause of morbidity and mortality especially in children less than five years, particularly in India. We present data on S. pneumoniae infections in children less than five years age group, with response to its serotype distribution, antibiotic resistance profile and available vaccines expected coverage. Methods: Children aged less than five, who were suspected for invasive pneumococcal disease were included in the study and their sterile body fluids were investigated for the presence of S. pneumoniae. Invasive S. pneumoniae isolates from sterile body fluids were identified by bile solubility and optochin susceptibility test. Pneumococcal serotyping was performed with co-agglutination technique and reconfirmed with multiplex PCR. Results: The most common pneumococcal serotypes causing invasive infections in children less than five years of age were 14, 19F, 5, 6A and 6B. Of the 114 S. pneumoniae isolates studied, 110 (96.4%) were non-susceptible to co-trimoxazole and 30 per cent were non-susceptible to erythromycin, 5.2 per cent of the isolates were non-susceptible to penicillin and only 0.8 per cent was non-susceptible to cefotaxime. Interpretation & conclusions: Our results indicate that PCV-10 can protect against 64 per cent of serotypes causing invasive pneumococcal infections. Use of PCV-13 in this region can provide increase in protection upto 74.6 per cent against serotypes causing invasive pneumococcal infections. Incorporating PCV-13 in the Universal Immunization Programme may provide incremental protection against IPD serotypes in the southern region of the country.