Epidemiological and clinical implications of asymptomatic malaria and schistosomiasis co-infections in a rural community in western Kenya

Abstract

Background Malaria and schistosomiasis present considerable disease burden in tropical and sub-tropical areas and severity is worsened by co-infections in areas where both diseases are endemic. Although pathogenesis of these infections separately is well studied, there is limited information on the pathogenic disease mechanisms and clinical disease outcomes in co-infections. In this study, we investigated the prevalence of malaria and schistosomiasis co-infections, and the hematologic and blood chemistry abnormalities in asymptomatic adults in a rural fishing community in western Kenya. Methods This sub-study used samples and data collected at enrollment from a prospective observational cohort study (RV393) conducted in Kisumu County, Kenya. The presence of malaria parasites was determined using microscopy and real-time-PCR, and schistosomiasis infection by urine antigen analysis (CCA). Hematological analysis and blood chemistries were performed using standard methods. Statistical analyses were performed to compare demographic and infection data distribution, and hematologic and blood chemistry parameters based on different groups of infection categories. Clinically relevant hematologic conditions were analyzed using general linear and multivariable Poisson regression models. Results From February 2017 to May 2018, we enrolled 671 participants. The prevalence of asymptomatic Plasmodium falciparum was 28.2% (157/556) and schistosomiasis 41.2% (229/562), with 18.0% (100/556) of participants co-infected. When we analyzed hematological parameters using Wilcoxon rank sum test to evaluate median (IQR) distribution based on malarial parasites and/or schistosomiasis infection status, there were significant differences in platelet counts (p = 0.0002), percent neutrophils, monocytes, eosinophils, and basophils (p < 0.0001 each). Amongst clinically relevant hematological abnormalities, eosinophilia was the most prevalent at 20.6% (116/562), whereas thrombocytopenia was the least prevalent at 4.3% (24/562). In univariate model, Chi-Square test performed for independence between participant distribution in different malaria parasitemia/schistosomiasis infection categories within each clinical hematological condition revealed significant differences for thrombocytopenia and eosinophilia (p = 0.006 and p < 0.0001, respectively), which was confirmed in multivariable models. Analysis of the pairwise mean differences of liver enzyme (ALT) and kidney function (Creatinine Clearance) indicated the presence of significant differences in ALT across the infection groups (parasite + /CCA + vs all other groups p < .003), but no differences in mean Creatinine Clearance across the infection groups. Conclusions Our study demonstrates the high burden of asymptomatic malaria parasitemia and schistosomiasis infection in this rural population in Western Kenya. Asymptomatic infection with malaria or schistosomiasis was associated with laboratory abnormalities including neutropenia, leukopenia and thrombocytopenia. These abnormalities could be erroneously attributed to other diseases processes during evaluation of diseases processes. Therefore, evaluating for co-infections is key when assessing individuals with laboratory abnormalities. Additionally, asymptomatic infection needs to be considered in control and elimination programs given high prevalence documented here.

Effect of Malaria and Schistosoma mansoni Coinfection on Selected Biochemical Profiles among Patients Attending Selected Health Institutions at Dembiya, Northwest Ethiopia

“…This finding was similar to studies conducted in Ethiopia that found significantly higher values of ALT, AST, direct bilirubin, and lower values of glucose and total protein in the S. mansoni monoinfected participants as compared to healthy participants [ 39 , 40 ]. In addition, this finding was similar with a study conducted in Western Kenya that found significantly higher median value of ALT in the malaria and S. mansoni -coinfected participants as compared to healthy participants [ 23 ]. This finding was also consistent with a study conducted in Yemen, which found significantly higher levels of AST, ALT, total bilirubin, and direct bilirubin in malaria patients compared to healthy individuals [ 9 ].…”

Schistosoma mansoni coinfection is associated with high Plasmodium falciparum infection intensity among 10 -15 year old children living along the Albert Nile in Uganda

“…Parasitic coinfections have been reported in several studies, as recently reviewed [8], among which are P. falciparum and S. mansoni coinfection [6][7][8]. In this study, we present ndings of a cross-sectional analysis set out to ascertain the association between S. mansoni infection and P. falciparum infection.…”

“…Additionally, WHO estimated 249 million malaria cases in the endemic areas [3]. Malaria and schistosomiasis coinfection has been reported in areas with high occurrence of both infections [6][7][8]. Additionally stunting among children has been shown in S. mansoni as well as P. falciparum [9] infection Coinfection of malaria and schistosomiasis is particularly common in sub Saharan Africa (SSA) [10].…”

Cloning, characterization, and inhibition of the novel β-carbonic anhydrase from parasitic blood fluke, Schistosoma mansoni

“… 1 , 2 It causes schistosomiasis and has been rated as the second most harmful parasite in the world; only malaria has been stated to cause more mortality. 3 , 4 Schistosoma mansoni is endemic in Africa, South America, the Caribbean, and the Middle East. 5 Schistosomiasis is an intestinal infection that produces acute symptoms of diarrhoea, 6 abdominal pain, 6 and fever.…”