Extant interspecific hybridization among trematodes within the Schistosoma haematobium species complex in Nigeria.

BACKGROUND: Natural interspecific hybridization between the human parasite (Schistosoma haematobium [Sh]) and bovine parasites (Schistosoma bovis [Sb], Schistosoma curassoni [Sc]) is increasingly reported in Africa. We developed a multi-locus PCR DNA-Seq strategy that amplifies two unlinked nuclear (transITS, BF) and two linked organellar genome markers (CO1, ND5) to genotype S. haematobium eggs collected from infected people in Ile Oluji/Oke Igbo, Ondo State (an agrarian community) and Kachi, Jigawa State (a pastoral community) in Southwestern and Northern Nigeria, respectively. PRINCIPAL FINDINGS: Out of a total of 219 urine samples collected, 57 were positive for schistosomes. All patients from Jigawa state possessed an Sh mitochondrial genome and were infected with a genetic profile consistent with an Sh x Sb hybrid based on sequences obtained at CO1, ND5, transITS and BF nuclear markers. Whereas samples collected from Ondo state were more varied. Mitonuclear discordance was observed in all 17 patients, worms possessed an Sb mitochondrial genome but one of four different genetic profiles at the nuclear markers, either admixed (heterozygous between Sh x Sc or Sh x Sb) at both markers (n = 10), Sh at BF and admixed at transITS (Sh x Sc) (n = 5), admixed (Sh x Sc) at BF and homozygous Sc at transITS (n = 1) or homozygous Sh at BF and homozygous Sc at transITS (n = 1). SIGNIFICANCE: Previous work suggested that zoonotic transmission of S. bovis in pastoral communities, where humans and animals share a common water source, is a driving factor facilitating interspecific hybridization. However, our data showed that all samples were hybrids, with greater diversity identified in Southwestern Nigeria, a non-pastoral site. Further, one patient possessed an S. bovis mitochondrial genome but was homozygous for S. haematobium at BF and homozygous for S. curassoni at transITS supporting at least two separate backcrosses in its origin, suggesting that interspecific hybridization may be an ongoing process.

Giardia intestinalis reshapes mucosal immunity toward a Type 2 response that attenuates inflammatory bowel-like diseases.

Diarrheal diseases are the second leading cause of death in children worldwide. Epidemiological studies show that co-infection with Giardia intestinalis decreases the severity of diarrhea. Here, we show that Giardia is highly prevalent in the stools of asymptomatic school-aged children. It orchestrates a Th2 mucosal immune response, characterized by increased antigen-specific Th2 cells, IL-25, Type 2-associated cytokines, and goblet cell hyperplasia. Giardia infection expanded IL-10-producing Th2 and GATA3+ Treg cells that promoted chronic carriage, parasite transmission, and conferred protection against Toxoplasma gondii-induced lethal ileitis and DSS-driven colitis by downregulating proinflammatory cytokines, decreasing Th1/Th17 cell frequency, and preventing collateral tissue damage. Protection was dependent on STAT6 signaling, as Giardia-infected STAT6-/- mice no longer regulated intestinal bystander inflammation. Our findings demonstrate that Giardia infection reshapes mucosal immunity toward a Type 2 response, which confers a mutualistic protection against inflammatory disease processes and identifies a critical role for protists in regulating mucosal defenses.

Urogenital schistosomiasis in Nigeria post receipt of the largest single praziquantel donation in Africa.

Schistosomiasis control efforts in Nigeria received a boost in 2016 when Merck Group made the largest single donation of praziquantel to an African country. We examined urine samples from 2,023 school age children from 15 locations in 10 states and an Internally Displaced Person's (IDP) camp in Nigeria. We recorded an overall Schistosoma haematobium prevalence of 10.4% in the 10 states that ranged between 6 - 37%, while prevalence in the IDP camp was 2.9%. The highest infection prevalence (37%) recorded was from the population in Wasai Dam area in Minjibir (Kano State), while five locations had no positive urine samples. We observed heavy intensity of infection (≥ 50 eggs/10 ml urine) in 87.9% of infected samples and co-occurrence of the eggs of S. haematobium and S. mansoni in urine for two participants. The overall prevalence we recorded is slightly above the national average (9.5%) reported in 2015. Our findings indicate that despite the ongoing administration of praziquantel in Nigeria, urogenital schistosomiasis is still prevalent with heavy intensity of infection. Large-scale epidemiological monitoring is required to monitor the efficacy of schistosomiasis control in Nigeria.

Performance evaluation of a popular malaria RDT in Nigeria compared with microscopy.

Malaria remains a public health problem in Sub-Saharan Africa. Prompt diagnosis and effective treatment are important in reducing morbidity and mortality associated with malaria especially among high-risk groups. This study evaluated the diagnostic performance of one of the popular malaria rapid diagnostic test (RDT) kit in Nigerian market which has not been investigated before in field-condition compared with microscopy as the gold standard. A total number of 250 children of 10 years and below were examined for malaria parasites using both microscopy and RDT in Uhogua community in Edo state and data were analysed using SPSS version 22. The prevalence of malaria by microscopy was 99.2% while only 55.2% were positive by RDT. Majority of the study populations were asymptomatic for malaria infection. RDT sensitivity and specificity compared to light microscopy was 69.08% and 66.67% respectively while the positive predictive value and negative predictive value were 99.6% and 1.77% respectively. The RDT accuracy was less than 70%. RDT cannot be relied upon alone for malaria diagnosis. Microscopy remains the gold standard for malaria diagnosis.

Prevalence and risk of malaria, anemia and malnutrition among children in IDPs camp in Edo State, Nigeria.

BACKGROUND: Malaria, anemia and malnutrition are global health challenges with significant morbidity and mortality, with higher rates among children particularly in Africa. Recently there has been displacement of over a million people due to different crisis in Nigeria. However, there is limited study on the public health issues facing these vulnerable populations. This study evaluated the prevalence and risk factors for malaria infection, anemia and malnutrition among children living in internally displaced persons (IDP) camp in Edo state, Nigeria. METHOD: A total of 250 children up to 10 years old were included in the study in the year 2018. Malaria infection was confirmed by rapid diagnostic tests. The hematocrit level was obtained using a centrifuge microhaematocrit and converted to haemoglobin using standard conversion while nutritional status was determined from anthropometric measurements collected, and demographic characteristics were obtained by the use of questionnaire. Anemia and malnutrition were defined according to World Health Organization standards. The logistic regression analysis was used to determine associations between predictor variables and primary outcomes. RESULT: Malaria infection and anemia were recorded for 55.2% and 54.0% of the children, respectively while malnutrition prevalence was 41.2% with wasting, underweight and stunting occurring in 0.04%, 11.2% and 39.2% respectively. Age was a significant risk factor for malaria with higher odds of having malaria infection in children 6-10 years of age [odds ratio (OR) = 2.032, P = 0.021] than in younger children. Being 6-10 years (OR = 2.307, P = 0.015) and having malaria infection (OR = 1.693, P = 0.048) were identified as significant risk factors of anemia while being in the age group of up to 5 years was the only significant risk factor (OR for the older age group = 0.251, P ≤ 0.001) associated with malnutrition. Specific attention needs to be paid to children in IDP camps. CONCLUSION: Anemia and malnutrition control should be integrated with existing malaria control and should include children above five years of age.

Modeling the risk of transmission of schistosomiasis in Akure North Local Government Area of Ondo State, Nigeria using satellite derived environmental data.

Schistosomiasis is a parasitic disease and its distribution, in space and time, can be influenced by environmental factors such as rivers, elevation, slope, land surface temperature, land use/cover and rainfall. The aim of this study is to identify the areas with suitable conditions for schistosomiasis transmission on the basis of physical and environmental factors derived from satellite imagery and spatial analysis for Akure North Local Government Area (LGA) of Ondo State. Nigeria. This was done through methodology multicriteria evaluation (MCE) using Saaty's analytical hierarchy process (AHP). AHP is a multi-criteria decision method that uses hierarchical structures to represent a problem and makes decisions based on priority scales. In this research AHP was used to obtain the mapping weight or importance of each individual schistosomiasis risk factor. For the purpose of identifying areas of schistosomiasis risk, this study focused on temperature, drainage, elevation, rainfall, slope and land use/land cover as the factors controlling schistosomiasis incidence in the study area. It is by reclassifying and overlaying these factors that areas vulnerable to schistosomiasis were identified. The weighted overlay analysis was done after each factor was given the appropriate weight derived through the analytical hierarchical process. The prevalence of urinary schistosomiasis in the study area was also determined by parasitological analysis of urine samples collected through random sampling. The results showed varying risk of schistosomiasis with a larger portion of the area (82%) falling under the high and very high risk category. The study also showed that one community (Oba Ile) had the lowest risk of schistosomiasis while the risk increased in the four remaining communities (Iju, Igoba, Ita Ogbolu and Ogbese). The predictions made by the model correlated strongly with observations from field study. The high risk zones corresponded to known endemic communities. This study revealed that environmental factors can be used in identifying and predicting the transmission of schistosomiasis as well as effective monitoring of disease risk in newly established rural and agricultural communities.

Environmental factors and the risk of urinary schistosomiasis in Ile Oluji/Oke Igbo local government area of Ondo State.

Geographic information systems are being increasingly used to show the distributions of disease where data for specific environmental risk factors are available. For successful transmission of schistosomiasis, suitable climatic conditions and biological events must coincide; hence its distribution and prevalence are greatly influenced by environmental factors affecting the population of snail intermediate hosts and human hosts. Prevalence and demographic data was obtained by parasitological examination of urine samples and questionnaire administration. The mean values of environmental factors corresponding to the local government area were obtained from remotely sensed images and data from climate research unit. The effects of the environmental factors were determined by using regression analysis to analyse the correlation of environmental factors to prevalence of schistosomiasis. There was a negative correlation between infection and elevation. There was a positive correlation between vegetation, rainfall, slope, temperature and prevalence of infection. There was also a weak negative correlation between proximity to water body and prevalence. The result shows the study area to be at low to high risk of infection.