Abstract
BACKGROUND: Sri Lanka introduced national bans restricting access to highly hazardous pesticides (HHPs) in 2008-11, and in 2013-16. An immediate drop in pesticide poisoning cases was observed after the introduction of the first ban, but there was a simultaneous rise in hospital admissions due to drugs, medicines and biological substances. However, the long-term trends in hospital admissions and deaths due to poisoning in Sri Lanka have not been investigated. We aimed to determine whether there have been changes in types of poisoning presenting to hospitals and their associated case fatality (CF) following two distinct periods of implementation of national bans of HHPs in Sri Lanka. METHODS: We conducted a retrospective observational study using routinely collected national-level hospital admissions data from Sri Lanka between 2004 and 2019 to examine trends in hospital admissions, deaths, and CF of different poisoning types. We included the following types: drugs, medicines and biological substances; pesticides; and non-medicinal products; and an additional group for other external causes. We calculated type-specific number of in-hospital cases and deaths per 100,000 population and annual CF, stratified by sex and age group. RESULTS: We found a reduction in hospital admission cases from both pesticide poisoning (58.5% between 2012 and 2017) and drugs, medicine, and biological substances following the implementation of the first HHPs bans in 2011. There was an increase in hospital admissions due to non-medicinal products and other external causes, but this did not translate into an increase in hospital deaths or CF. We observed a sharp decrease in CF due to pesticide poisoning following the first ban (50% between 2008 and 2012), with no concurrent rise in CF due to other types of poisoning and non-poisoning substances, which remained low throughout the study period. CONCLUSIONS: The implementation of national bans of HHPs led to a reduction in number of admissions as well as CF due to pesticide poisoning in hospitals in Sri Lanka, with no evidence of substitution to other types of poisonings. The reversal of the upward trend in hospital admissions due to pesticide and medicinal poisonings suggests that the bans contributed to a reduction in admissions from these types of poisoning.