Aaron Remkes (Hamburg / DE), Ralf Krumkamp (Hamburg / DE), Tahinamandranto Rasamoelina (Antananarivo / MG), Ravo Razafindrakoto (Antananarivo / MG), N. Matthieu Nantenaina (Antananarivo / MG), Jacques Hainasoa (Fianarantsoa / MG), Nicolas Jouanard (Massy / FR), Philippe Martel (Massy / FR), Dr Valentina Marchese (Hamburg / DE), Nathalie Fischer (Hamburg / DE), Johanna Saalfrank (Hamburg / DE), Prof. Jürgen May (Hamburg / DE), Raphael Rakotozandrindrainy (Antananarivo / MG), prof Rivo Andry Rakotoarivelo (Fianarantsoa / MG), Dr. Daniela Fusco (Hamburg / DE)
Abstract text
Introduction: Schistosomiasis is a parasitic disease of poverty spread by freshwater snails. Humans become infected through contact with contaminated freshwater. Therefore, occupational activities such as rice cultivation are believed to be a risk factor due to long and regular contact with contaminated water. It is to be noted that 70 percent of Madagascar's population is engaged in agriculture, mainly rice cultivation.
Objectives: The present study aims to investigate the prevalence of schistosomiasis and its risk factors in rural Madagascar.
Patients & Methods: A cross-sectional study was conducted in 44 villages in the Vatomandry District. 1204 households were randomly selected based on their accessibility and agricultural profile, with a maximum of 5 participants per household. A total of 5199 participants were included meeting following inclusion criteria: voluntary consent, age over 5 years, no fever or Covid vaccination in the last 2 weeks, and no pregnancy. Door-to-door surveying was used to obtain sociodemographic background and dietary behaviour data based on the "UN Guidelines for Measuring Household and Individual Dietary Diversity". 5196 urine and 995 blood samples were collected for Schistosome infection analysis by means of urine based rapid diagnostic tests (RDT) and PCR.
Results: A total of 1204 households with a median household size of 5 members (IQR=5-6) were surveyed. Among participants (n=5199), 56.1% were female. The mean age was 27 years (IQR=15-44), with 29.8% under 18. 58.1% of the total sample tested positive for schistosomiasis by RDT. 45.5% of adults work in agriculture. 58.5% of women and 57.6% of men tested positive. 45.4% of those under 18 tested positive, whereas 63.5% of adults did. Among adults who reported being farmers, 73.4% tested positive, 56.1% of non-farmers, and 43.5% of unemployed. 14.2% reported having been treated against schistosomiasis in the past, of whom 74.2% reported having been treated more than 12 months ago.
Conclusion: Our preliminary data show that a high proportion of the population tested positive by RDT for schistosomiasis. The highest proportion of individuals testing positive was among farmers, who were also by far the largest occupational group. The positive rate among men and women was almost identical. Additional analysis is underway to further identify the most common species and risk factors for infection. This study will help improve preventive measures to control schistosomiasis.