Description of 3,180 Courses of Chelation with Dimercaptosuccinic Acid in Children ≤5 y with Severe Lead Poisoning in Zamfara,Northern Nigeria: A Retrospective Analysis of Programme Data

In 2010,médecins sans frontières (msf) discovered extensive lead poisoning impacting several thousand children in rural northern nigeria. an estimated 400 fatalities had occurred over 3 mo. the us centers for disease control and prevention (cdc) confirmed widespread contamination from lead-rich ore being processed for gold,and environmental management was begun. msf commenced a medical management programme that included treatment with the oral chelating agent 2,3-dimercaptosuccinic acid (dmsa,succimer). here we describe and evaluate the changes in venous blood lead level (vbll) associated with dmsa treatment in the largest cohort of children ≤5 y of age with severe paediatric lead intoxication reported to date to our knowledge.in a retrospective analysis of programme data,we describe change in vbll after dmsa treatment courses in a cohort of 1,156 children ≤5 y of age who underwent between one and 15 courses of chelation treatment. courses of dmsa of 19 or 28 d duration administered to children with vbll ≥ 45 µg/dl were included. impact of dmsa was calculated as end-course vbll as a percentage of pre-course vbll (ecp). mixed model regression with nested random effects was used to evaluate the relative associations of covariates with ecp. of 3,180 treatment courses administered,36% and 6% of courses commenced with vbll ≥ 80 µg/dl and ≥ 120 µg/dl,respectively. overall mean ecp was 74.5% (95% ci 69.7%–79.7%); among 159 inpatient courses,ecp was 47.7% (95% ci 39.7%–57.3%). ecp after 19-d courses (n = 2,262) was lower in older children,first-ever courses,courses with a longer interval since a previous course,courses with more directly observed doses,and courses with higher pre-course vblls. low haemoglobin was associated with higher ecp. twenty children aged ≤5 y who commenced chelation died during the period studied,with lead poisoning a primary factor in six deaths. monitoring of alanine transaminase (alt),creatinine,and full blood count revealed moderate alt elevation in <2.5% of courses. no clinically severe adverse drug effects were observed,and no laboratory findings required discontinuation of treatment. limitations include that this was a retrospective analysis of clinical data,and unmeasured variables related to environmental exposures could not be accounted for.oral dmsa was a pharmacodynamically effective chelating agent for the treatment of severe childhood lead poisoning in a resource-limited setting. re-exposure to lead,despite efforts to remediate the environment,and non-adherence may have influenced the impact of outpatient treatment.please see later in the article for the editors' summary.