BACKGROUND: Possible severe bacterial infections (pSBI) continue to be a leading cause of global neonatal mortality annually. With the recent publications of simplified antibiotic regimens for treatment of pSBI where referral is not possible, it is important to know how and where to target these regimens, but data on the incidence and outcomes of pSBI are limited. METHODS: We used data prospectively collected at 7 rural community-based sites in 6 low and middle income countries participating in the NICHD Global Network's Maternal and Newborn Health Registry, between January 1, 2010 and December 31, 2013. Participants included pregnant women and their live born neonates followed for 6 weeks after delivery and assessed for maternal and infant outcomes. RESULTS: In a cohort of 248,539 infants born alive between 2010 and 2013, 32,088 (13 %) neonates met symptomatic criteria for pSBI. The incidence of pSBI during the first 6 weeks of life varied 10 fold from 3 % (Zambia) to 36 % (Pakistan), and overall case fatality rates varied 8 fold from 5 % (Kenya) to 42 % (Zambia). Significant variations in incidence of pSBI during the study period, with proportions decreasing in 3 sites (Argentina, Kenya and Nagpur, India), remaining stable in 3 sites (Zambia, Guatemala, Belgaum, India) and increasing in 1 site (Pakistan), cannot be explained solely by changing rates of facility deliveries. Case fatality rates did not vary over time. CONCLUSIONS: In a prospective population based registry with trained data collectors, there were wide variations in the incidence and case fatality of pSBI in rural communities and in trends over time. Regardless of these variations, the burden of pSBI is still high and strategies to implement timely diagnosis and treatment are still urgently needed to reduce neonatal mortality. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov ( NCT01073475 ).
