Intestinal parasitic infections and risk factors for infection in Kenyan children with and without HIV infection.

It has been reported that HIV infection is not a risk factor for Entamoeba species infection but is for Giardia intestinalis assemblage B in children living in Western Kenya. This study aimed to investigate the prevalence of and the risk factors for Entamoeba spp. and G. intestinalis infection in children living in Nairobi, Kenya. This cross-sectional study included 87 children with HIV [HIV(+)] and 85 without HIV [HIV(-)]. Stool and blood samples were collected for the detection of the parasites by PCR and immunological analyses using flow cytometry. Sociobehavioral and hygienic data were collected using questionnaires and analyzed statistically. The prevalence of Entamoeba spp. infection was significantly lower in the HIV(+) than in the HIV(-) children (63.2% vs. 78.8%, P = 0.024), whereas the prevalence of G. intestinalis infection was not (27.6% vs. 32.9%, P = 0.445). "Not boiling drinking water" (adjusted odds ratio [aOR]: 3.8, P = 0.044) and "helping in nursery care" (aOR: 2.8, P = 0.009) were related to G. intestinalis assemblage B infection, and "CD4/CD8 ratio ≥1" was related to Entamoeba spp. infection (aOR: 3.3, P = 0.005). In stratified regression analyses, HIV infection was negatively associated with G. intestinalis assemblage B infection in females (aOR: 0.3, P = 0.022), but positively associated in males (aOR 3.8, P = 0.04). These results suggest that G. intestinalis assemblage B infection is related to hygienic conditions, while Entamoeba spp. infection is an indicator of better immunological status, and that the role of HIV infection in Giardia infection may differ between Kenyan boys and girls.

Entamoeba species infection in patients seeking treatment for diarrhea and abdominal discomfort in Mukuru informal settlement in Nairobi, Kenya.

Entamoeba histolytica is the only pathogenic species of the Entamoeba genus and is morphologically identical to E. dispar/E. moshkovskii (Entamoeba complex) hence cannot be microscopically differentiated. The other Entamoeba spp. found in humans (E. hartmanni, E. polecki, and E. coli) can be differentiated morphologically from this Entamoeba complex. However, some of their morphologic features overlap making differential diagnosis difficult. This study aimed at determining the occurrence of Entamoeba spp. in patients seeking treatment for diarrhea and/or abdominal discomfort at two clinics in Mukuru informal settlement in Nairobi, Kenya. Faecal samples were collected from 895 patients, examined microscopically following direct wet smear and formal-ether concentration methods. Entamoeba spp. positive faecal samples were subjected to DNA extraction and species-specific nested polymerase chain reaction of the 18S ribosomal RNA (rRNA). By microscopy, Entamoeba spp. cysts or trophozoites were detected in 114/895 (12.7%, 95% Confidence Interval (CI) 10.6-15.1) faecal samples. By nested PCR, the prevalence was: E. histolytica (7.5%, 95% CI 5.9-9.4, 67/895) and E. dispar (8.2%, 95% CI 6.5-10.2, 73/895). Among the Entamoeba spp. complex positive samples, nested PCR detected E. coli and E. hartmanni DNA in 63/114 (55.3%) and 37/114 (32.5%), samples respectively. Among the E. histolytica/E. dispar PCR negative samples (32.5%), 21 (18.4%) contained cysts of either E. coli (19) or E. hartmanni (2) by nested PCR. Entamoeba spp. infections were most common among participants aged 21-30 years; however it was not significant (P = 0.7). Entamoeba spp. infections showed an inverse relationship with diarrhea being most common among participants without diarrhea (P = 0.0). The difference was significant for E. histolytica (P = 0.0) but not significant for E. dispar (P = 0.1). Only E. dispar infections were significantly associated with sex (P = 0.0). This study highlights the need for differentiation of E. histolytica from other Entamoeba spp. by molecular tools for better management of amoebiasis.

The prevalence of intestinal parasites and associated risk factors in school-going children from informal settlements in Nakuru town, Kenya.

BACKGROUND: Intestinal parasites are a major public health problem in the developing world and have attracted increasing levels of interest from health researchers over the past decade. Epidemiology-based studies have shown that the prevalence of intestinal parasites is high and they frequently recur in regions with poor sanitation and inadequate sewerage facilities. In this study, we determined the prevalence of intestinal parasites, their egg intensities per sample, and associated risk factors in an informal settlement. METHODS: This was a cross-sectional study conducted in three randomly selected public primary schools located in the informal settlements of Nakuru town. A total of 248 stool samples were collected from asymptomatic pupils and screened, using the Kato Katz technique, for infections caused by soil-transmitted helminths (STH). A random subset of stool samples (n=96) was also screened by polymerase chain reaction (PCR) to detect intestinal protozoa. Socio-demographic variables were collected using a pre-tested structured questionnaire; these data were analysed to identify risk factors for infection. RESULTS: The overall prevalence of intestinal parasites was 17.3% (43/248 pupils). The overall prevalence of both STH and intestinal protozoan parasites was 1.2% and 41.7%, respectively. The most commonly diagnosed STH infection was Trichuris trichiura (1.2%), followed by hookworms (0.4%) and Ascaris lumbricoides (0.4%). The prevalence of intestinal protozoan parasites ranged from 0% to 38.5% and included Entamoeba histolytica, Entamoeba hartmanni, Entamoeba dispar, Giardia intestinalis, and Entamoeba coli. All infections were light, with an egg intensity <100 for each of the STH infections. The prevalence of multiple infections, including intestinal protozoan parasites, was 5.2% (n=5) and 0.4% (n=1) for STH in the subset samples. Finally, our analysis identified several significant risk factors for intestinal parasitic infections, including goat rearing (p=0.046), living in a home with an earthen floor (p=0.022), the number of rooms in the household (p=0.035), and the source of food (p=0.016). CONCLUSION: The low prevalence of intestinal parasites in the informal settlements of Nakuru may be attributed to improvements in hygiene and sanitation, deworming, and general good health practices that are facilitated by the Department of Public Health.

Extremely diversified haplotypes observed among assemblage B population of Giardia intestinalis in Kenya.

In molecular epidemiological studies of Giardia intestinalis, an pathogenic intestinal flagellate, due to the presence of allelic sequence heterogeneity (ASH) on the tetraploid genome, the image of haplotype diversity in the field remains uncertain. Here we employed the nine assemblage B positive stool samples, which had previously reported from Kenyan children, for the clonal sequence analysis of multiple gene loci (glutamate dehydrogenase (GDH), triosephosphate isomerase (TPI), and beta-giardin (BG)). The diversified unique assemblage B haplotypes as GDH (n = 67), TPI (n = 84), and BG (n = 62), and the assemblage A haplotypes as GDH (n = 7), TPI (n = 14), and BG (n = 15), which were hidden in the previous direct-sequence results, were detected. Among the assemblage B haplotypes, Bayesian phylogeny revealed multiple statistically significant clusters (9, 7, and 7 clusters for GDH, TPI, and BG, respectively). A part of the clusters (2 for GDH and 1 for BG), which included >4 haplotypes from an individual sample, indicated the presence of co-transmission with multiple strains sharing a recent ancestor. Locus-dependent discrepancies, such as different compositions of derived samples in clusters and different genotyping results for the assemblages, were also observed and considered to be the traces of both intra- and inter-assemblage genetic recombination respectively. Our clonal sequence analysis for giardial population, which applied firstly in Kenya, could reveal the higher rates of ASH far beyond the levels reported in other areas and address the complex population structure. The clonal analysis is indispensable for the molecular field study of G. intestinalis.

Perceptions and Experiences of School Teachers During the Implementation of a School-Based Deworming Activity in Kenya.

BACKGROUND: Primary school teachers are key stakeholders in the success of school-based deworming activity as they are responsible for drug administration and provision of health education to the School-Age Children (SAC). In Kenya, the National School-Based Deworming Programme (NSBDP) for control of soil-transmitted helminths and schistosomiasis was initiated in the year 2012 in prioritised areas. By the year 2013, over 6 million SAC had been treated. The present study sought to assess the teachers' perceptions and experiences of the school-based deworming activity in an effort to improve programme effectiveness. METHODS: Qualitative data were collected, using in-depth interviews, in 4 subcounties of the coastal region of Kenya. Using purposive selection, 1 primary school teacher from each of the 38 schools also purposively selected participated in the study. The data were audio-recorded, transcribed, coded and analysed manually by study themes which included: reason for being selected for training to administer drugs; perceptions of training content and duration; experiences during drug acquisition, administration and record-keeping and motivation to continue participating in the deworming of school-age children. RESULTS: Half of the teachers indicated that they were selected to administer drugs to children as they were responsible for school health matters. The duration and content of the training were considered sufficient, and no challenges were faced during drug acquisition. Challenges faced during drug administration included non-compliance and experience of side effects of the drugs. No major problems were experienced in record-keeping, although the teachers felt that the forms needed to be simplified. Improvement of the children's health and class performance was reported as a source of motivation to the teachers to continue administering the drugs. Fellow teachers were reported to have given moral support while over half of the respondents indicated that parents did not provide much support. CONCLUSION: Generally, teachers have positive experiences and perceptions of the deworming activity. There is, however, a need to involve all stakeholders especially the parents through the school board of management to help counter non-compliance and possibly support in providing meals to the children to help minimise side effects after drug consumption. Inadequate moral support and incentives are negative factors on the teachers' motivation.

Lessons from implementing mass drug administration for soil transmitted helminths among pre-school aged children during school based deworming program at the Kenyan coast.

BACKGROUND: The 2012 London declaration which committed to "sustaining, expanding and extending drug access programmes to ensure the necessary supply of drugs and other interventions to help control soil-transmitted helminths (STH) by 2020" has seen many countries in Africa roll out mass drug administration (MDA) especially among school age children. In Kenya, however, during the National school-based deworming exercise, pre-school aged children (PSAC) have to access treatment at primary schools as the pre-school teachers are not trained to carry out deworming. With studies being conducted on the effectiveness of MDAs, the experiences of key education stakeholders which could improve the programme by giving best practices, and challenges experienced have not been documented. METHODS: This was a cross-sectional qualitative study using Focus group discussions (FGDs) and Key informant interviews (KIIs). It was conducted in 4 sub-counties with high STH prevalence at the Kenyan coast (Matuga, Malindi, Lunga Lunga and Msambweni) to understand best practices for implementing MDA among PSAC.FGDs categorized by gender were conducted among local community members, whereas KIIs involved pre-school teachers, primary school teachers, community health extension workers (CHEWs) and opinion leaders. Participants were purposefully selected with the saturation model determining the number of interviews and focus groups. Voice data collected was transcribed verbatim then coded and analyzed using ATLAS.Ti version 6. RESULTS: Majority of the primary school teachers and CHEWs reported that they were satisfied with the method of mobilization used and the training tools. This was however not echoed by the pre-school teachers, parents and chiefs who complained of being left out of the process. Best practices mentioned included timely drug delivery, support from pre-school teachers, and management of side effects. Overcrowding during the drug administration day, complexity of the forms (for instance the 'S form') and long distance between schools were mentioned as challenges. CONCLUSION: There is need to utilize better sensitization methods to include the local administration as well as the parents for better uptake of the drugs. Extending deworming training to pre-school teachers will enhance the national deworming programme.

Knowledge, practices and perceptions of geo-helminthes infection among parents of pre-school age children of coastal region, Kenya.

BACKGROUND: Soil-transmitted helminthes (STHs) are common human parasitic diseases in most of the developing world particularly in Kenya. The ongoing National School-Based Deworming Programme (NSBDP) was launched in 2012 and is currently targeting 28 of the 47 endemic Counties. In an effort to improve treatment intervention strategies among Pre-School Age Children (PSAC) attending Early Childhood Development Centres (ECDC), we sought to assess parents' knowledge, perceptions and practices on worm infection. METHODOLOGY: We conducted a qualitative cross-sectional study in four endemic sub-counties of two counties of coastal region of Kenya. A total of 20 focus group discussions (FGDs) categorized by gender were conducted among parents of pre-school age children. Participants were purposively selected based on homogenous characteristics with the saturation model determining the number of focus group discussions conducted. The data collected was analyzed manually by study themes. FINDINGS: The majority of the parents had knowledge on worms and modes of transmission of the parasitic infections among the pre-school children. Also, most of the participants knew the causes of worm infection and the pre- disposing factors mentioned included poor hygiene and sanitation practices. Due to poor knowledge of signs and symptoms, misconceptions about the drugs administered during the NSBDP were common with a large majority of the parents indicating that the drugs were ineffective in worm control. The findings also indicated that most of the participants sought medical care on the onset of the signs and symptoms of worm infestation and preferred services provided at public health facilities as opposed to private health facilities or buying drugs from the local market citing mistrust of such services. Cultural beliefs, high cost of building and availability of vast pieces of land for human waste disposal were factors that contributed to low or lack of latrine ownership and usage by a large majority of the respondents. CONCLUSIONS: Our results show that to a large extent the parents of the pre-school age children have information on worm infections. However, some cultural beliefs and practices on the pathology and mode of transmission mentioned could be a hindrance to prevention and control efforts. There is need to implement health promotion campaigns to strengthen the impact of control strategies and reduce infection.

Positive correlation of HIV infection with Giardia intestinalis assemblage B but not with assemblage A in asymptomatic Kenyan children.

A cross-sectional molecular epidemiological study of Giardia intestinalis infection was conducted among asymptomatic Kenyan children with (n = 123) and without (n = 111) HIV infection. G. intestinalis assemblage B infection was positively correlated with HIV infection [HIV (+), 18.7% vs. HIV (-), 11.7%; P = 0.013], whereas assemblage A infection was not [HIV (+), 4.1% vs. HIV (-), 6.3%; P = 0.510]. Thus, HIV infection is a risk factor for G. intestinalis assemblage B infection but not for assemblage A infection.

Lower prevalence of Entamoeba species in children with vertically transmitted HIV infection in Western Kenya.

A cross-sectional molecular epidemiological study of Entamoeba species was conducted among asymptomatic Kenyan children with (n = 123) and without (n = 111) HIV infection. The prevalence of E. histolytica was low (0.4%). Entamoeba species infection was inversely related with HIV infection [HIV(+): 29.3% vs. HIV(-): 55.0%, P < 0.001]: multiple-species infection was related to higher CD4 T-cell counts. Thus, HIV infection is not a risk factor for amebic infection, and multiple-species infection can be an indicator of better immune status.

Use of geospatial modeling to predict Schistosoma mansoni prevalence in Nyanza Province, Kenya.

BACKGROUND: Schistosomiasis, a parasitic disease that affects over 200 million people, can lead to significant morbidity and mortality; distribution of single dose preventative chemotherapy significantly reduces disease burden. Implementation of control programs is dictated by disease prevalence rates, which are determined by costly and labor intensive screening of stool samples. Because ecological and human factors are known to contribute to the focal distribution of schistosomiasis, we sought to determine if specific environmental and geographic factors could be used to accurately predict Schistosoma mansoni prevalence in Nyanza Province, Kenya. METHODOLOGY/PRINCIPAL FINDINGS: A spatial mixed model was fit to assess associations with S. mansoni prevalence in schools. Data on S. mansoni prevalence and GPS location of the school were obtained from 457 primary schools. Environmental and geographic data layers were obtained from publicly available sources. Spatial models were constructed using ArcGIS 10 and R 2.13.0. Lower S.mansoni prevalence was associated with further distance (km) to Lake Victoria, higher day land surface temperature (LST), and higher monthly rainfall totals. Altitude, night LST, human influence index, normalized difference vegetation index, soil pH, soil texture, soil bulk density, soil water capacity, population, and land use variables were not significantly associated with S. mansoni prevalence. CONCLUSIONS: Our model suggests that there are specific environmental and geographic factors that influence S. mansoni prevalence rates in Nyanza Province, Kenya. Validation and use of schistosomiasis prevalence maps will allow control programs to plan and prioritize efficient control campaigns to decrease schistosomiasis burden.

Community health workers' experiences and perspectives on mass drug administration for schistosomiasis control in western Kenya: the SCORE Project.

Abstract. The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) includes communitywide treatment in areas with ≥ 25% prevalence of schistosomiasis along the shores of Lake Victoria using community health workers (CHWs). The CHWs are key drivers in community-owned mass drug administration (MDA) intervention programs. We explored their experiences and perceptions after initial MDA participation. Unstructured open-ended group discussions were conducted after completion of MDA activities. Narratives were obtained from CHWs using a digital audio recorder during the group discussion, transcribed verbatim and translated into English where applicable. Thematic decomposition of data was done using ATLAS.t.i. software. From the perspective of the CHWs, factors influencing MDA compliance included drug side effects, food supply stability, and conspiracy theories about the "real" purpose of treatment. The interest of CHWs to serve as community drug distributors stemmed from both intrinsic and extrinsic factors. Feedback from CHWs can promote more effective MDA in rural Kenyan communities.

Schistosoma mansoni morbidity among school-aged children: a SCORE project in Kenya.

Schistosomiasis control programs aim to reduce morbidity but are evaluated by infection prevalence and intensity reduction. We present baseline cross-sectional data from a nested cohort study comparing indicators of morbidity for measuring program impact. Eight hundred twenty-two schoolchildren 7-8 years of age from Nyanza Province, Kenya, contributed stool for diagnosis of Schistosoma mansoni and soil-transmitted helminths (STH) and blood smears for malaria, and were evaluated for anemia, quality of life, exercise tolerance, anthropometry, and ultrasound abnormalities. Schistosoma mansoni, STH, and malaria infection prevalence were 69%, 25%, and 8%, respectively. Only anemia and S. mansoni infection (adjusted odds ratio [aOR] = 1.70; confidence interval [CI] = 1.03-2.80), and hepatomegaly and heavy S. mansoni infection (aOR = 2.21; CI = 1.19-4.11) were associated. Though anemia and hepatomegaly appeared most useful at baseline, additional morbidity indicators may be sensitive longitudinal measures to evaluate schistosomiasis program health impact.

CD26/dipeptidyl peptidase IV (CD26/DPPIV) is highly expressed in peripheral blood of HIV-1 exposed uninfected female sex workers.

BACKGROUND: Design of effective vaccines against the human immunodeficiency virus (HIV-1) continues to present formidable challenges. However, individuals who are exposed HIV-1 but do not get infected may reveal correlates of protection that may inform on effective vaccine design. A preliminary gene expression analysis of HIV resistant female sex workers (HIV-R) suggested a high expression CD26/DPPIV gene. Previous studies have indicated an anti-HIV effect of high CD26/DPPIV expressing cells in vitro. Similarly, high CD26/DPPIV protein levels in vivo have been shown to be a risk factor for type 2 diabetes. We carried out a study to confirm if the high CD26/DPPIV gene expression among the HIV-R were concordant with high blood protein levels and its correlation with clinical type 2 diabetes and other perturbations in the insulin signaling pathway. RESULTS: A quantitative CD26/DPPIV plasma analysis from 100 HIV-R, 100 HIV infected (HIV +) and 100 HIV negative controls (HIV Neg) showed a significantly elevated CD26/DPPIV concentration among the HIV-R group (mean 1315 ng/ml) than the HIV Neg (910 ng/ml) and HIV + (870 ng/ml, p < 0.001). Similarly a FACs analysis of cell associated DPPIV (CD26) revealed a higher CD26/DPPIV expression on CD4+ T-cells derived from HIV-R than from the HIV+ (90.30% vs 80.90 p = 0.002) and HIV Neg controls (90.30% vs 82.30 p < 0.001) respectively. A further comparison of the mean fluorescent intensity (MFI) of CD26/DPPIV expression showed a higher DPP4 MFI on HIV-R CD4+ T cells (median 118 vs 91 for HIV-Neg, p = 0.0003). An evaluation for hyperglycemia, did not confirm Type 2 diabetes but an impaired fasting glucose condition (5.775 mmol/L). A follow-up quantitative PCR analysis of the insulin signaling pathway genes showed a down expression of NFκB, a central mediator of the immune response and activator of HIV-1 transcription. CONCLUSION: HIV resistant sex workers have a high expression of CD26/DPPIV in tandem with lowered immune activation markers. This may suggest a novel role for CD26/DPPIV in protection against HIV infection in vivo.