Epidemiological investigation on envenomation: from theory to practice

a better understanding of the epidemiology of envenoming would improve care, provided that the survey is representative, reliable and accurate. several types of surveys could help to clarify the incidence, severity, circumstances, factors and determinants of envenomations. the relevant information may be collected and analyzed from hospital records or case report forms (for retrospective studies) or established from a protocol of longitudinal observation of cases attended at health facilities during a given period (prospective study). the household survey includes interviewing all or part of the population of a locality with a standardized questionnaire to obtain information on the circumstances of the accident. finally, standardized questionnaires can be administered to health workers in order to ascertain the circumstances and procedures of care, the availability and use of treatment and the level of knowledge of agents. correctly performed, these surveys should promote the organization of the management of snakebites or scorpion stings because they identify the location of envenomation and quantify the needs. however, the surveyed localities should be chosen for relevance to be representative of the territory, just as methodology and analysis should be rigorous in order to give useful results.