Undereporting of acute pesticide poisoning in Tanzania: modelling results from two cross-sectional studies.

Elikana E Lekei,Leslie London,Aiwerasia V Ngowi

doi:10.1186/s12940-016-0203-3

Abstract

BackgroundAcute pesticide poisoning (APP) is known to cause serious injuries to end users globally but the magnitude of this problem in Tanzania is not well known. This study aimed to determine the extent and pattern of underreporting of APP in Tanzania to inform the development of a surveillance system and appropriate interventions.MethodsThis study integrates findings from two recent Tanzanian studies. A household survey established the proportion of poisoned farmers in a typical rural area who reported to hospital for a pesticide poisoning. Only 5 of the 112 farmers who reported attending hospital due to poisonings could be traced in medical records at the facilities they claimed to have attended. The 95% confidence interval for this ratio (5/112) was used to generate a high and low boundary for the estimates. Three under-estimation factors were generated for sensitivity analysis to adjust for under-reporting. A review of health facilities in three regions of Tanzania collected prospective data on admissions for APP in 2006 to generate population-based APP incidence rates stratified by circumstances of poisoning (occupational, accidental, suicide, and unknown). Sensitivity analysis was conducted involving adjustment for high and low boundaries of the under-reporting of occupational APP and an adjustment for different scenario allocations of cases with ‘unknown’ circumstances to different combinations of known circumstances.ResultsThe study estimated the rate of occupational poisoning as ranging from 11.3–37.7 cases/million to 84.3–279.9 cases per million. The rate of all poisonings (occupational and non-occupational) ranged from 24.45–48.01 cases per million to 97.37–290.29 cases per million. Depending on the choice of scenario and under-reporting correction factor used, occupational APP could comprise from 52.2 to 96% of all APP cases.ConclusionThe study confirms that data on APP in Tanzanian hospitals are poorly reported and that occupational circumstances are particularly overlooked in routine facility-based surveillance. Occupational APP needs to be taken more seriously in addressing prevention measures. A comprehensive surveillance system for APP should consider multiple data sources including community self-reporting in order to achieve better coverage.

Highlights

Acute pesticide poisoning (APP) is known to cause serious injuries to end users globally but the magnitude of this problem in Tanzania is not well known
Of the total 230 cases of APP recorded over the year, 8% were recorded as occupational circumstances and 19% were of unknown circumstances (Table 2)
12.21 a The baseline rates were obtained in a prospective follow-up of 10 facilities in four regions of Tanzania over 12 months in 2006 bThe 44 cases of APP were allocated in equal proportion to suicide, occupational circumstances and accident/homicide cThe 44 cases of APP with were allocated in proportion to the baseline rates of APP for suicide, occupational circumstances and accident/homicide (6.71: 1.18: 3.67, respectively) occupational APP in routine health information systems

Summary

Introduction

Acute pesticide poisoning (APP) is known to cause serious injuries to end users globally but the magnitude of this problem in Tanzania is not well known. Studies in different parts of the world report incidence rates of acute pesticide poisoning of 20/100,000 in Central America [1], 2300/100,000 in Nicaragua [3], 180 per 100,000 in Sri Lanka [4] and 4.2/100,000 in South Africa [5] These differences in rates reflect differences in use conditions, toxicity of agents and, most likely, sources used to compile the data [6]. Most published studies rely on data from cases presenting to health facilities and recorded in national registries or health information systems and include only the most obvious poisonings such as those requiring hospitalization This means that the real toll from pesticides, including milder and non-hospitalised cases, is likely to be greater than reported. Despite the apparent magnitude of this problem, accurate data to inform public health decision-making about the risks of pesticide poisoning is lacking

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