Prevalence and factors associated with human Taenia solium taeniosis and cysticercosis in twelve remote villages of Ranomafana rainforest, Madagascar

Abstract

Background Infections with the tapeworm Taenia solium (taeniosis and cysticercosis) are Neglected Tropical Diseases (NTD) highly endemic in Madagascar. These infections are however underdiagnosed, underreported and their burden at the community level remains unknown especially in rural remote settings. This study aims at assessing the prevalence of T. solium infections and associated risk factors in twelve remote villages surrounding Ranomafana National Park (RNP), Ifanadiana District, Madagascar. Methodology A community based cross-sectional survey was conducted in June 2016. Stool and serum samples were collected from participants. Tapeworm carriers were identified by stool examination. Taenia species and T. solium genotypes were characterised by PCR and sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Detection of specific anti-cysticercal antibodies (IgG) or circulating cysticercal antigens was performed by ELISA or EITB/Western blot assays. Principal findings Of the 459 participants with paired stool and blood samples included ten participants from seven distinct villages harbored Taenia spp. eggs in their stools samples DNA sequencing of the cox1 gene revealed a majority of T. solium Asian genotype (9/10) carriage. The overall seroprevalences of anti-cysticercal IgGs detected by ELISA and EITB were quite similar (27.5% and 29.8% respectively). A prevalence rate of 12.4% of circulating cysticercal antigens was observed reflecting cysticercosis with viable cysts. Open defecation (Odds Ratio, OR = 1.5, 95% CI: 1.0–2.3) and promiscuity with households of more than 4 people (OR = 1.9, 95% CI: 1.1–3.1) seem to be the main risk factors associated with anticysticercal antibodies detection. Being over 15 years of age would be a risk factor associated with an active cysticercosis (OR = 1.6, 95% CI: 1.0–2.7). Females (OR = 0.5, 95% CI: 0.3–0.9) and use of river as house water source (OR = 0.3, 95% CI: 0.1–1.5) were less likely to have cysticercosis with viable cysts. Conclusions/Significance This study indicates a high exposure of the investigated population to T. solium infections with a high prevalence of cysticercosis with viable cysts. These data can be useful to strengthen public health interventions in these remote settings.

The epidemiology of humanTaenia soliuminfections: a systematic review of the distribution in Eastern and Southern Africa

“…Thus, cases reported as either taeniosis or taenia spp could not for instance be differentiated from cases due to T. saginata which is also widely distributed in ESA [27]. Only two studies, one from Madagascar and another from Zambia were able to confirm the T. solium species after collecting tapeworm proglottids [20,21].…”

“…Regarding human cysticercosis cases, tapeworm carriers are the sole cause of infection in both rural and urban areas of the ESA region [10,35]. Tapeworm carriers, if not treated, pose a risk to themselves if they ingest infective eggs leading to cysticercosis but can also pose a risk to other people in contact [21,36]. A study in Madagascar found at a household level, the overall seroprevalence of IgG detected by Ab-ELISA and EITB within the same household in which a tapeworm carrier has been detected was 46% and 34% respectively [21].…”

“…Tapeworm carriers, if not treated, pose a risk to themselves if they ingest infective eggs leading to cysticercosis but can also pose a risk to other people in contact [21,36]. A study in Madagascar found at a household level, the overall seroprevalence of IgG detected by Ab-ELISA and EITB within the same household in which a tapeworm carrier has been detected was 46% and 34% respectively [21]. Individual human cysticercosis cases were identified from a third of the 27 ESA countries.…”

“…(Table 6) without specifying the type of species. In only two records from Madagascar and Zambia, T. solium was confirmed using PCR [20,21]. Microscopy only was employed for 53 studies, and copro Ag-ELISA only in three studies.…”

A Marked Decline in Taenia solium Taeniasis and Cysticercosis Infections in China: Possible Reasons from the Ecological Determinants Perspective

“…These changes can successfully cut off the T. solium transmission route. Although these two factors have often been described in the literature [2,58,59], those articles have not adequately covered the fundamental importance of decreasing human cysticercosis by halting disease transmission.…”