Abstract:
Development and spread of resistance to current antimalarial strategies underline the necessity to develop innovative strategies. Recent studies suggest that ivermectin has a mosquitocidal effect and ivermectin mass administration might become an effective and complementary strategy in malaria elimination and eradication. However, ivermectin has been in use in many African Countries for over 25 years in Mass Drug Administration for onchocerciasis and lymphatic filariasis control.
The purpose of the current study was to investigate whether there has been a change in malaria prevalence in the months following ivermectin mass administration during the past three years.
A retrospective study was undertaken in the Navrongo War Memorial Hospital between May and June 2015. Data from 2,652 randomly selected patients were extracted from consulting room registers and admission and discharge books for the past three years. Variable of interest included date of visit, diagnoses, age, sex and area of residence. Dates of ivermectin mass drug administration were considered as point of reference. Malaria prevalence was compared three months before and after ivermectin MDA using two-group test of proportions. Pearson Chi-square and logistic regression were used to determine factors associated with malaria prevalence and strength of association.
On the whole, malaria prevalence was 24.8% (329/1,327, 95% CI: 22.5 - 27.1) before ivermectin mass administration and 26.3% (349/1,325, 95% CI: 24.0 - 28.8) after ivermectin mass administration with not statistically significant difference (-1.5%, 95% CI: -4.9 - 1.8; p = 0.361). On annual basis, malaria prevalence after ivermectin mass administration significantly increased during the year 2013 from 27 to 42% (p < 0.001) 0.016). Sex, age groups, source of data and year of ivermectin mass administration were found to be significantly associated with malaria prevalence (p < 0.01). A stabilization or decrease was observed when malaria baseline prevalence during the month preceding ivermectin mass administration was low and lasted for about two months.
We hypothesize that ivermectin administered in MDA can be used as an effective tool to reduce malaria prevalence. But its effectiveness will depend on the baseline prevalence before ivermectin distribution and may last about two months. Further studies are needed to confirm these findings.
