Factors associated with the performance and cost-effectiveness of using lymphatic filariasis transmission assessment surveys for monitoring soil-transmitted helminths: a case study in Kenya.

Transmission assessment surveys (TAS) for lymphatic filariasis have been proposed as a platform to assess the impact of mass drug administration (MDA) on soil-transmitted helminths (STHs). This study used computer simulation and field data from pre- and post-MDA settings across Kenya to evaluate the performance and cost-effectiveness of the TAS design for STH assessment compared with alternative survey designs. Variations in the TAS design and different sample sizes and diagnostic methods were also evaluated. The district-level TAS design correctly classified more districts compared with standard STH designs in pre-MDA settings. Aggregating districts into larger evaluation units in a TAS design decreased performance, whereas age group sampled and sample size had minimal impact. The low diagnostic sensitivity of Kato-Katz and mini-FLOTAC methods was found to increase misclassification. We recommend using a district-level TAS among children 8-10 years of age to assess STH but suggest that key consideration is given to evaluation unit size

Laboratory and semi-field evaluation of long-lasting insecticidal nets against leishmaniasis vector, Phlebotomus (Phlebotomus) duboscqi in Kenya

Background & objectives: Phlebotomine sandflies are vectors of leishmaniases and other diseases.Long-lasting insecticidal nets (LLINs) as possible tools for control have not been widely testedagainst them. The objective of this study was to determine the efficacy of Olyset® Net and PermaNet®LLINs alongside a local brand, K-O Tab® treated net (Supanet) against Phlebotomus duboscqifemale sandflies.Methods: Four replicates of unwashed and 20x washed Olyset Nets and PermaNets, K-O Tabtreatedand untreated Supanet and ‘no net’ treatments were evaluated against sandflies within thelaboratory by tunnel tests and in semi-field conditions in the greenhouse model for their efficacy.Results: All bednets allowed entry of P. duboscqi sandflies and subsequent blood-feeding. Olysetnet’s blood feeding inhibition was significantly higher than that of Supanet in the laboratory butnot in semi-field condition. Of the LLINs, only Olyset net had sandflies that could not feedsignificantly more than those of Supanet. Additionally, no significant efficacy difference wasobserved between LLINs washed 20x and unwashed ones. The only significant difference noted innumber of sandflies that were found dead or paralyzed within bednets in the semi-field conditionwas between Olyset and K-O Tab treated Supanet. In the laboratory, unwashed Olyset had asignificantly higher number of sandflies killed than all other bednet treatments.Conclusion: Olyset net use in areas where sandflies are nuisance biters and/or disease vectorscould be more beneficial in preventing sandfly bites than other tested bednets. It is recommendedthat mesh sizes of LLINs should be smaller for control of sandflies than those used for control ofmosquitoes

The adverse effects of albendazole and praziquantel in mass drug administration by trained schoolteachers

Eastern and Southern Africa Centre of International Parasite Control (ESACIPAC) conducted stool examinations for soil transmitted helminthiases (STH) and Schistosoma mansoni, among school children in Mwea Division, Central Kenya where both infections are endemic. Mass drug administrations (MDAs) were then conducted in 2004 and 2005 using schoolteachers trained on how to administer treatment, physically and psychologically prepare the children to take the medication, have them eat before treatment, handle minor and refer serious side effects to local health facilities. Local health workers were on standby to help manage severe side effects. This study examined side effects of the drugs and the teachers’ preparedness to handle the children when such effects occurred. No serious side effects requiring referral to the health centre occurred and the minor ones observed were temporal. In 2005 children in Mwea schools were treated with albendazole 400mg and praziquantel 40mg/kg body weight while those of Ndia, a neighboring division treated with only albendazole 400mg since there was low S.mansoni prevalence. Monitoring of side effects was done in two schools of Ndia and in three of Mwea through a questionnaire distributed to grade three pupils a week after treatment. Of 73 pupils from Mwea, 49.7% reported incidences of stomachache, vomiting/nausea, headache and dizziness whereas 39.2% of 186 from Ndia experienced incidences of cough, stomachache and headache. This shows that more pupils from Mwea, (albendazole and praziquantel) than from Ndia (albendazole alone) experienced minor side effects. These results show that both drugs have temporary, minor side effects, which can be managed by trained schoolteachers by ensuring that the school children do not swallow the drugs on an empty stomach and rest immediately after swallowing the drugs but should be closely monitored by health personnel. In this study, one trained schoolteacher could administer treatment to three hundred children in one day, which makes the approach cost effective and should be adopted nationally.Keywords: albendazole, praziquantel, soil transmitted helminthiasis, schistosomiasi

Risk Factors associated with Intestinal Parasitic Infections on School Children in Thika District, Central Kenya

The effective prevention and control of intestinal parasitic infections requires the identification of risk factors that contribute to their transmission, among high risk groups. Objectives: To determine the prevalence and associated risk factors of intestinal parasitic infections among school children in public primary schools in Thika district. Methods: A cross-sectional study, involving 377 schoolchildren, was conducted in Thika District Central Kenya. Interviews, observation, and anthropometric indices assessment were used to identify the risk factors predisposing the children to infections with parasites. Stool specimens were examined using Katz method for helminthes and formal ether concentration techniques for protozoan infections. Data was analysed using SPSS version. Results: Ten species of intestinal parasites were identified. Ascaris lumbricoides 74 (19.6%) and hookworm 50 (13.3%) while Entamoeba histolytica and Entamoeba coli were the common protozoa in the study area. A higher prevalence of Ascaris lumbricoides was reported among children in the slums. Entamoeba histolytica infection was associated with eating raw tubers and fruits (p< 0.001) in rural children. Iodamoeba bustchili infection was significantly associated with stunted children in rural children. Several factors contribute to high prevalence of intestinal parasites in school going children in Thika District. Keywords: Risk factors, school-age, children, Anthropometrics indice

Effectiveness of albendazole on soil transmitted nematodes among school children-: a case of Kakamega County, Kenya

Background: Recent assessment by WHO on Soil Transmitted Nematodes (STN) point that their morbidity is still high in people mainly in children. A. lumbricoides globally infects 1.2 billion people and T. trichiura 795 million worldwide. Infections with Ancylostoma duodenale and Necator americanus 740 million leading to 135,000 deaths per year. It became necessary to find out the effectiveness of Albendazole on soil transmitted Nematodes among school children- a case of kakamega county, kenya.Methodology: Study respondents were selected fom public primary school children in Kakamega County. A total of 731 and 665 (pre & post) children in 7 primary schools in three sub counties of Kakamega County were recruited in the study.Pre-treatment survey was done in March, 2014 and follow up in September 2014. Fecal samples were examined for the presence of STN . 14 days after treatment using Kato- Katz method. The total number of eggs were expressed as eggs/gm of feaces (epg). Pretreatment prevalence was 43.5% for Ascaris lumbricoides, 1.8% for hookworm and 0.9% for Trichuris trichiura.Results: Mean intensity of hookworm, A. lumbricoides and T. trichiura infections in the pre-and post-surveys were reduced by 1.2%, 98.4% and 100% respectively. Prevalence decreased to 2.3% for Ascaris lumbricoides and 0 % for T. trichiura. Post treatment prevalence of A. lumbricoides and T. trichiura infections were significantly reduced by 94.8% and 100% respectively. A slight increase in hookworm prevalence was observed. However, this increase was not significant (p=0.993).Conclusion: The therapeutic efficacy of Albendazole indicated a good reduction in parasite burden. Albendazole satisfactorily reduced STN infection while for hookworm there was a non-significant increase in prevalence.Keywords: Cure rate, egg reduction rate, albendazole, Keny

Current Status of Soil-Transmitted Helminths among School Children in Kakamega County, Western Kenya

Background. School age children are at high risk of soil-transmitted helminth (STH) worldwide. In Kenya, STH infections in children remain high despite the periodic administration of anthelmintic drugs. Our study assessed the prevalence and intensity of STH in primary school-aged children in Kakamega County, western Kenya. Methodology. We carried out a cross-sectional study on a population of 731 children attending 7 primary schools in March 2014. Children aged 4–16 years were examined for STH by the quantitative Kato-Katz technique. Infection intensities were expressed as eggs per gram (epg) of faeces. Findings. Among 731 school children examined for STH, 44.05% were infected. Highest prevalence of STH was in Shitaho primary school where 107 participants were examined and 62.6% were infected with mean intensity of 11667 epg. Iyenga had the least prevalence where 101 participants were examined and 26.7% were infected with mean intensity of 11772 epg. A. lumbricoides was the most prevalent STH species with 43.5% infected, while hookworm infections were low with 1.8% infected. Conclusion. Prevalence of STHs infections in Kakamega County remains high. We recommend guidelines and other control strategies to be scaled up to break transmission cycles

Modeling the Interruption of the Transmission of Soil-Transmitted Helminths Infections in Kenya: Modeling Deworming, Water, and Sanitation Impacts.

Kenya, just like other countries with endemic soil-transmitted helminths (STH), has conducted regular mass drug administration (MDA) program for the last 5 years among school aged children as a way to reduce STH infections burden in the country. However, the point of interruption of transmission of these infections still remains unclear. In this study, we developed and analyzed an age structured mathematical model to predict the elimination period (i.e., time taken to interrupt STH transmission) of these infections in Kenya. The study utilized a deterministic age structured model of the STH population dynamics under a regular treatment program. The model was applied to three main age groups: pre-school age children (2-4 years), school age children (5-14 years), and adult populations (≥15 years) and compared the impact of two interventions on worm burden and elimination period. The model-simulated results were compared with the 5 year field data from the Kenyan deworming program for all the three types of STH (Ascaris lumbricoides, Trichuris trichiura, and hookworm). The model demonstrated that the reduction of worm burden and elimination period depended heavily on four parameter groups; drug efficacy, number of treatment rounds, MDA and water, sanitation and hygiene (WASH) coverage. The analysis showed that for STH infections to be eliminated using MDA alone in a short time period, 3-monthly MDA plan is desired. However, complementation of MDA with WASH at an optimal (95%) coverage level was most effective. These results are important to the Kenyan STH control program as it will guide the recently launched Breaking Transmission Strategy

Associations between school- and household-level water, sanitation and hygiene conditions and soil-transmitted helminth infection among Kenyan school children.

BACKGROUND: Soil-transmitted helminths, a class of parasitic intestinal worms, are pervasive in many low-income settings. Infection among children can lead to poor nutritional outcomes, anaemia, and reduced cognition. Mass treatment, typically administered through schools, with yearly or biannual drugs is inexpensive and can reduce worm burden, but reinfection can occur rapidly. Access to and use of sanitation facilities and proper hygiene can reduce infection, but rigorous data are scarce. Among school-age children, infection can occur at home or at school, but little is known about the relative importance of WASH in transmission in these two settings. METHODS: We explored the relationships between school and household water, sanitation, and hygiene conditions and behaviours during the baseline of a large-scale mass drug administration programme in Kenya. We assessed several WASH measures to quantify the exposure of school children, and developed theory and empirically-based parsimonious models. RESULTS: Results suggest mixed impacts of household and school WASH on prevalence and intensity of infection. WASH risk factors differed across individual worm species, which is expected given the different mechanisms of infection. CONCLUSIONS: No trend of the relative importance of school versus household-level WASH emerged, though some factors, like water supply were more strongly related to lower infection, which suggests it is important in supporting other school practices, such as hand-washing and keeping school toilets clean

Epidemiology of coinfection with soil transmitted helminths and Plasmodium falciparum among school children in Bumula District in western Kenya.

BACKGROUND: Many school children living in Africa are infected with plasmodia and helminth species and are consequently at risk of coinfection. However, the epidemiology of such coinfection and the implications of coinfection for children's health remain poorly understood. This study describes the epidemiology of Ascaris lumbricoides-Plasmodium and hookworm-Plasmodium coinfection among school children living in western Kenya and investigates the associated risk factors. METHODS: As part of a randomized trial, a baseline cross-sectional survey was conducted among school children aged 5-18 years in 23 schools in Bumula District. Single stool samples were collected to screen for helminth infections using the Kato-Katz technique and malaria parasitaemia was determined from a finger prick blood sample. Demographic and anthropometric data were also collected. RESULTS: Overall, 46.4% of the children were infected with Plasmodium falciparum while 27.6% of the children were infected with at least one soil transmitted helminth (STH) species, with hookworm being the most common (16.8%) followed by A. lumbricoides (15.3%). Overall 14.3% of the children had STH-Plasmodium coinfection, with hookworm-Plasmodium (9.0%) coinfection being the most common. Geographical variation in the prevalence of coinfection occurred between schools. In multivariable logistic regression analysis, hookworm was positively associated with P. falciparum infection. In stratified analysis, hookworm infection was associated with increased odds of P. falciparum infection among both boys (P < 0.001) and girls (P = 0.01), whereas there was no association between A. lumbricoides and P. falciparum. CONCLUSION: These findings demonstrate STH infections are still prevalent, despite the ongoing national deworming programme in Kenya, and that malaria parasitaemia is widespread, such that coinfection occurs among a proportion of children. A subsequent trial will allow us to investigate the implications of coinfection for the risk of clinical malaria