Extent of morbidity associated with schistosomiasis infection in Malawi: a review paper

Abstract

Data on the extent of the burden due to schistosomiasis is sparse in most Sub-Saharan African countries. However, this data is crucial for triggering medical attention. A review of extent of morbidity and determinants associated with schistosomiasis in Malawi was therefore conducted to quantify the infection in order to concretise the need for medical intervention. A systematic and traditional search strategy was used to find literature for the review, whilst exclusion and inclusion criteria were used to identify appropriate articles. Logistic regression curves of epidemiological model Y = (a + bxc)/(1 + bxc) and the recommendation that schistosomiasis prevalence can be used to estimate morbidity were employed to quantify morbidity at various infection stages. Morbidity was quantified as a direct proportion of the population and the respective national schistosomiasis prevalence. Findings showed that both S. mansoni and S. haematobium are present in Malawi with the latter highly prevalent (50%). Furthermore, out of the estimated population of 16,829 million, approximately 8.4 million have schistosomiasis, with about 4.4 million of these aged 18 years and below. The most frequent manifestation is Katayama syndrome, while ascites is the lowest, impacting about 3.0 million and 960 individuals, respectively. Localised studies on association of schistosomiasis infection to risk factors such as occupation, age and gender found odds ratio (OR) ranging from 1.29 to 5.37. Morbidity due to schistosomiasis is high in Malawi. It is therefore recommended that a more detailed study on the determinants of high schistosomiasis and re-evaluation of the current control measures be conducted if the current morbidity statistics are to be remarkably reduced.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-015-0053-1) contains supplementary material, which is available to authorized users.

Biomphalaria pfeifferiSnails and Intestinal Schistosomiasis, Lake Malawi, Africa, 2017–2018

“…This finding highlights emergence of intestinal schistosomiasis, not previously documented here ( 5 , 7 , 8 ) or detected in this region by the most recent national survey (F. Fleming, Schistosomiasis Control Initiative, Imperial College London; 2017 Dec 20; pers. comm).…”

“…Absence of cox 1 genetic diversity in the B. pfeifferi snails we sampled implies a limited number or even a single founder event, but as conditions for autochthonous transmission became favorable, after introduction of S. mansoni flukes, intestinal schistosomiasis in local schoolchildren has emerged. This finding is of substantial public health concern in light of current control efforts, which consist only of annual praziquantel distribution in schools ( 7 , 8 ). We recommend increased surveillance of snails and characterization of schistosomes, along with intensified control interventions to arrest further spread of intestinal schistosomiasis.…”

An outbreak of intestinal schistosomiasis, alongside increasing urogenital schistosomiasis prevalence, in primary school children on the shoreline of Lake Malawi, Mangochi District, Malawi

“…Intensity of S. mansoni infection as eggs per gram (epg) was classi ed as: light (1-99 epg), medium (100-399 epg) and heavy (≥ 400 epg) according to WHO guidelines [11]. To assess putative pathology associated with intestinal schistosomiasis [5], stools were screened for FOB using ALLTEST ® cassettes (Access Diagnostic Tests UK Ltd, Aylsham, UK).…”

“…MDA is typically guided upon country-wide mapping information which is usually developed from inspection of ve schools per district [3]. By contrast, intestinal schistosomiasis, caused by Schistosoma mansoni, is not considered endemic within the lake, as being congruent with the absence of Biomphalariapfeifferi, an obligatory intermediate snail host and keystone snail species for parasite transmission [1,4,5].…”

Toward Health Management of Major Labour Force Generation by Using Infection Control Countermeasures for Haematobium Schistosomiasis –assumed to be related to occupational risk- in the Republic of Malawi

“…MDA, however, may be a more promising approach to disease control in Malawi [29]. The Malawi National Schistosomiasis Control Programme does not have well-documented evidence of the universal drug treatment [30]. As the first step in breaking the chain of chronic and repetitive infection, the first year of school enrollment is considered an appropriate time for the first MDA after birth.…”