Pneumococcal pneumonia after a preceding respiratory viral illness is associated with morbidity and mortality in infants. Our study sought to determine how pneumococcal carriage impacted illness severity due to respiratory syncytial virus (RSV) or human metapneumovirus (hMPV) in infants 0-6 months in a low resource setting in South Asia without pneumococcal vaccination. Previous studies in this population found an overall 79.4% prevalence of pneumococcal carriage in ages 1-36 months with higher rates of carriage among healthy controls as compared to those with respiratory illness.
Infants were enrolled at time of birth in a maternal influenza immunization trial conducted in rural Nepal from 2011-2014. Weekly household-based active surveillance was performed from birth to six months to assess for infant respiratory illness, defined as fever, cough, difficulty breathing, wheeze, or otorrhea. Mid-nasal swabs were collected and tested by PCR for RSV, hMPV and streptococcus pneumoniae with inclusion of first illness episode in the surveillance period. Disease severity was defined using the World Health Organization Integrated Management of Childhood Illness criteria.
Altogether, 247 (73.5%) of 336 infants with RSV and 154 (83.7%) of 184 infants with hMPV had S. pneumoniae detected. Mean age at RSV illness with concurrent pneumococcal carriage was 97.0 days (91.3-102.6) versus 72.8 days (63.3-82.4) for infants without carriage (P<0.001). Mean age at hMPV illness with concurrent pneumococcal carriage was 101.3 days (93.9-108.7) versus 77.2 days (56.5-98.0) for infants without carriage (P=0.01). Frequency of reported lower respiratory tract infection did not differ with or without carriage (RSV: 64.4% vs. 65.2% respectively; p=0.89, hMPV: 52.6% vs. 50.0% p=0.79). S. pneumoniae PCR cycle threshold value did not differ by duration or severity of RSV or hMPV illness episode.
High rates of pneumococcal carriage were observed with RSV and hMPV illness episodes in a birth cohort of infants in rural Nepal. The majority of infants with RSV or hMPV illness had pneumococcus detected at the time of first observed illness. However, no increase in RSV or hMPV illness severity or duration was seen with pneumococcal carriage.
J. Kuypers, None
J. Tielsch, None
J. Katz, None
L. Shrestha, None
S. Khatry, None
S. C. Leclerq, None
M. C. Steinhoff, None
H. Y. Chu, Sanofi Pasteur: Grant Investigator , Grant recipient . Novavax: Grant Investigator , Grant to co-investigator's institution .