Assessing the burden and risk factors of sudden infant death syndrome (SIDS) and other sleep related infant deaths in Africa: a case study of Zambia

BACKGROUND: In wealthier countries, sudden infant death syndrome (SIDS) is consistently mentioned as a leading preventable cause of infant mortality. However, in Africa, little is known about SIDS. The general view in the Global Health community is that SIDS is not a significant cause of infant mortality in low resource settings. But is this assumption correct? It seems illogical that SIDS would only be confined to high-income settings. An alternative hypothesis is that we are in a situation where SIDS in Africa has historically not been a priority area for research. Consequently, we may have fallen into the common trap where the absence of evidence is misconstrued as evidence of absence. The focus of this thesis is to challenge these assumptions. METHODS: We do this in stages. First, we present results of a systematic review of published studies about SIDS in Africa. Second, we analyze a recently collected unique data set consisting of verbal autopsy data from the next of kin of several hundred deceased infants to attempt to quantify the burden of apparent SIDS deaths. Third, we assess the burden of canonical risk factors for SIDS using prospectively collected survey data. And fourth, we analyze individual attitudes, knowledge, and experience with SIDS collected via focus groups and in-depth interviews to better understand awareness of SIDS and its risk factors, and the potential that these could be modified. RESULTS: The systematic review confirmed that SIDS is poorly studied in Africa. Most of the research on SIDS in Africa comes from South Africa. The incidence of SIDS was high, with reported incidence rates of between 3.01 to 3.70 per 1000 live births in South Africa compared to 0.3 per 1000 live births in the U.S. Bedsharing and prone/lateral sleeping were universally prevalent in countries where these were assessed. In Zambia, 7.4% of decedent infants who died at home died suddenly and unexpectedly, with 5.4% presumably dying of SIDS. In surveys, nearly all infants (89.5%) shared a bed with an adult during sleep, and nearly two-thirds slept (73%) in the lateral position. Infants rarely slept in the recommended supine/back position. In focus group discussions, mothers indicated that they felt the supine sleep position posed an aspiration risk to the infant. Most cited health care workers and experienced women in the community as sources of information on sleep practices. CONCLUSION: Contrary to the prevailing view of SIDS in low to middle-income countries, in Africa and Zambia specifically, SIDS may be a significant cause of infant mortality, but it is going unrecognized or unreported. Public health interventions in Africa and Zambia are overlooking SIDS as an important cause of infant mortality. Interventions to prevent SIDS, such as laying the infant to sleep on the back, are low cost and will be worthwhile in reducing the high infant mortality rates in these settings