Epidemiology of soil transmitted helminth and Strongyloides stercoralis infections in remote rural villages of Ranomafana National Park, Madagascar

Abstract

Soil-transmitted helminth (STH) infections carry the highest number of disability adjusted life years among all neglected tropical diseases, disproportionately affecting low-income countries such as Madagascar. This study describes the epidemiology of STH and S. stercoralis infections in twelve remote villages surrounding Ranomafana National Park (RNP), Ifanadiana, Madagascar. Questionnaires and stool samples were collected from 574 subjects from random households. The Kato-Katz method and spontaneous sedimentation technique were used to examine stool samples for evidence of infection. Infection prevalence rates were 71.4% for Ascaris lumbricoides (95% CI: 67.7-75.1), 74.7% for Trichuris trichiura (95% CI: 71.1-78.2), 33.1% for hookworm (95% CI: 29.2-36.9), and 3.3% for Strongyloides stercoralis (95% CI: 1.84-4.77). Participants who were older in age (OR = 0.96; 95% CI: 0.95-0.99) and who had a high school education (OR = 0.17; 95% CI: 0.04-0.77) were less likely to be infected with a STH. Females were less likely to be infected with A. lumbricoides (OR = 0.52; 95% CI: 0.33-0.82). Participants living in villages further from the main road were more likely to be infected with a STH (F = 4.00, p = 0.02). Overall, this study found that 92.5% (95% CI: 90.3-94.6) of the people living in rural regions near RNP have at least one STH infection. This calls into question the current preventative chemotherapy (PC) program in place and suggests that further medical, socioeconomic, and infrastructural deveopments are needed to reduce STH prevalence rates among this underserved population.

High prevalence of intestinal parasite infestations among stunted and control children aged 2 to 5 years old in two neighborhoods of Antananarivo, Madagascar

“…trichiura and A . lumbricoides , respectively [ 14 ], although helminth infestations are rare in other places, such as the city of Mahajunga (≤3%), where protozoans are dominant (such as Blastocystis sp. 69.8%) [ 44 ].The majority of intestinal parasites, mostly intestinal helminths, are acquired via fecal-oral transmission.…”

“…trichiura was the most commonly encountered parasite (84.6%) followed by A . lumbricoides (72.4%) [ 14 ]. Three different types of IPs were identified in 14 districts of Madagascar in 2008–2009 from children under five years of age suffering or not of diarrheal disease.…”

Immunoglobulin recognition of fecal bacteria in stunted and non-stunted children: findings from the Afribiota study

“…However, as has been observed previously, IgA-targeting tended not to correlate with taxonomic abundance [ 19 , 21 ]. One notable difference between the two study populations is the burden of intestinal helminths, which are almost absent in CAR due to successful deworming campaigns but are widespread in Madagascar [ 41 ]. Helminths are known to elicit robust IgA responses, and some of this induced IgA has off-target specificity to the bacterial microbiota [ 42 ], offering a possible explanation for the increased IgA-targeting in Madagascar.…”

Kankanet: An artificial neural network-based object detection smartphone application and mobile microscope as a point-of-care diagnostic aid for soil-transmitted helminthiases

“…lumbricoides 71.3% (95% CI 67.7–75.1); T . trichiura 74.7% (95% CI 71.1–78.2); hookworm 33.1% (95% CI 29.2–36.9) [28]. Following the calculations for a binary diagnostic test for the species with the lowest prevalence, hookworm, with a predicted sensitivity of the test of 90% and a 10% margin of error, the required sample size to have adequate power was determined to be 115.…”