Study Population
A detailed report on the methods and protocol used for the Nicaraguan
Pediatric Influenza Cohort (NPICS) has been described
previously20,21. Briefly, the primary aim of the NPICS
study is to assess the burden, incidence, and seasonality of influenza
in Nicaragua. However, while most infectious disease studies focus on a
single pathogen or syndrome, NPICS was developed with the goal of
assessing multiple respiratory pathogens and can test stored samples for
additional pathogens. The NPICS study is an ongoing prospective cohort
study initiated in 2011 and includes children aged 0–14 years,
residing in District II in Managua, Nicaragua. Legal guardians are
encouraged to bring their children to the Health Center Sócrates Flores
Vias (HCSFV), at the first sign of illness and receive free medical care
and are thus incentivized to use this health outpost as opposed to
seeking care at other medical clinics. Initial enrollment for the cohort
study was conducted in 2011 by randomly sampling children aged 3–11
years who were enrolled in a previous cohort study for influenza within
District II, and additional children aged 0-2 were recruited through
house-to-house visits within the catchment area. The age distribution of
the NPICS cohort is representative of children of
Nicaragua20 and spatially representative of district
II in Managua20. Additional children aged 0–2 years
were recruited from houses throughout the study catchment area. Children
≤ 4 weeks old are enrolled monthly into NPICS and age out of the study
on their 15th birthday. In this study, we assess those
enrolled in NPICS from 2011–2016.