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Legge H, Kazungo K, Muli S, Elson L, Mwongeli J, Halliday KE, Ochwal V, Oswald W, Dreibelbis R, Njomo D, Mwandawiro C, Fillinger U, Pullan R, Kepha S. Identifying Potential Determinants of Faecal Contamination on Domestic Floors in Three Settings in Rural Kenya: A Mixed Methods Analysis. ENVIRONMENTAL HEALTH INSIGHTS 2024; 18:11786302241246454. [PMID: 38737960 PMCID: PMC11088304 DOI: 10.1177/11786302241246454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 03/21/2024] [Indexed: 05/14/2024]
Abstract
Observational evidence suggests that household floors may be an important domain for the transmission of enteric and parasitic infections. However, little work has been done to investigate how household floors can become contaminated with human and animal faeces. This study uses a mixed methods approach to postulate the proximal and distal determinants of household floor contamination with faeces in groups of rural villages in 3 counties in Kenya (Bungoma, Kwale and Narok). Quantitative data was collected through a household census and analysed descriptively and using mixed effects logistic regression models. Qualitative data was collected through unstructured observations of daily routines and in-depth interviews. These data were analysed thematically with case memos produced for routine activities that were hypothesised to be determinants of floor contamination. Possible proximal determinants of floor contamination included; (1) animal contact with floors; (2) child faeces disposal, and; (3) floor cleaning routines. Distal determinants are suggested to be rooted in the socioeconomic, environmental, and cultural context in which households were located and included; (1) the type and number of animals owned by households; (2) presence/absence of dedicated shelters for housing animals at night, which impacted whether sleeping or cooking areas were exposed to animals; (3) Accessibility of inside spaces to poultry and other roaming animals; (4) ownership of an improved floor; (5) ability of animals to access neighbours compounds; (6) seasonal changes in weather. These results will be of use in identifying the contexts in which faecal contamination of domestic floors may be contributing towards transmission of enteric and parasitic infections and in designing effective interventions to prevent this exposure.
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Affiliation(s)
- Hugo Legge
- London School of Hygiene & Tropical Medicine, UK
| | - Karisa Kazungo
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Sharon Muli
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Lynne Elson
- KEMRI-Wellcome Trust, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, UK
| | - Jacinta Mwongeli
- Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | | | - Victoria Ochwal
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - William Oswald
- London School of Hygiene & Tropical Medicine, UK
- Global Health Division, International Development Group, RTI International, Research Triangle Park, NC, USA
| | | | - Doris Njomo
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Charles Mwandawiro
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Ulrike Fillinger
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | | | - Stella Kepha
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
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Elson L, Kamau C, Koech S, Muthama C, Gachomba G, Sinoti E, Chondo E, Mburu E, Wakio M, Lore J, Maia M, Adetifa I, Orindi B, Bejon P, Fillinger U. Tungiasis among children in Kenya is associated with poor nutrition status, absenteeism, poor school performance and high impact on quality of life. PLoS Negl Trop Dis 2024; 18:e0011800. [PMID: 38776337 DOI: 10.1371/journal.pntd.0011800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 06/04/2024] [Accepted: 05/10/2024] [Indexed: 05/24/2024] Open
Abstract
Tungiasis is a highly neglected tropical skin disease caused by the sand flea, Tunga penetrans. The flea burrows into the skin inducing a strong inflammatory response, leading to pain and mobility restrictions with potential impacts on quality of life. Few countries implement control efforts and there are few data on the impact of the disease to support policy decisions. We conducted a survey to determine the impact of tungiasis among primary school children across nine counties of Kenya. A total of 10,600 pupils aged 8 to 14 years were randomly selected from 97 primary schools and examined for tungiasis. For 81 cases and 578 randomly selected controls, anthropometric measurements were made, and school attendance and exam scores were collected from school records. Of those with tungiasis, 73 were interviewed regarding their quality of life using a tungiasis-specific instrument. Mixed effect ordered logistic and linear models were used to assess associations between disease status and impact variables. Compared to uninfected pupils, those with tungiasis had lower weight-for-age z-scores (adjusted β -0.41, 95% CI: -0.75-0.06, p = 0.020), missed more days of school the previous term (adjusted Incidence Rate Ratio: 1.49, 95% CI: 1.01-2.21, p = 0.046) and were less likely to receive a high score in mathematics (aOR 0.18, 95% CI: 0.08-0.40, p<0.001) and other subjects. Pupils with severe disease (clinical score >10) were four times more likely to experience severe pain than those with mild disease (OR 3.96, 95% CI: 1.35-11.64, p = 0.012) and a higher impact on their quality of life than those with mild disease (aOR 3.57, 95% CI: 1.17-10.8, p = 0.025) when adjusted for covariates. This study has demonstrated tungiasis has a considerable impact on children's lives and academic achievement. This indicates the need for integrated disease management for school-aged children to protect their physical and cognitive development and their future prospects.
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Affiliation(s)
- Lynne Elson
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust, Kilifi, Kenya
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | | | | | | | | | | | | | | | | | - Marta Maia
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust, Kilifi, Kenya
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Ifedayo Adetifa
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust, Kilifi, Kenya
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Benedict Orindi
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust, Kilifi, Kenya
| | - Phillip Bejon
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust, Kilifi, Kenya
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Ulrike Fillinger
- International Centre for Insect Physiology and Ecology (icipe), Nairobi, Kenya
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Matharu AK, Ouma P, Njoroge MM, Amugune BL, Hyuga A, Mutebi F, Krücken J, Feldmeier H, Elson L, Fillinger U. Identification of tungiasis infection hotspots with a low-cost, high-throughput method for extracting Tunga penetrans (Siphonaptera) off-host stages from soil samples-An observational study. PLoS Negl Trop Dis 2024; 18:e0011601. [PMID: 38377105 PMCID: PMC10906885 DOI: 10.1371/journal.pntd.0011601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 03/01/2024] [Accepted: 02/02/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND The sand flea, Tunga penetrans, is the cause of a severely neglected parasitic skin disease (tungiasis) in the tropics and has received little attention from entomologists to understand its transmission ecology. Like all fleas, T. penetrans has environmental off-host stages presenting a constant source of reinfection. We adapted the Berlese-Tullgren funnel method using heat from light bulbs to extract off-host stages from soil samples to identify the major development sites within rural households in Kenya and Uganda. METHODS AND FINDINGS Simple, low-cost units of multiple funnels were designed to allow the extraction of >60 soil samples in parallel. We calibrated the method by investigating the impact of different bulb wattage and extraction time on resulting abundance and quality of off-host stages. A cross-sectional field survey was conducted in 49 tungiasis affected households. A total of 238 soil samples from indoor and outdoor living spaces were collected and extracted. Associations between environmental factors, household member infection status and the presence and abundance of off-host stages in the soil samples were explored using generalized models. The impact of heat (bulb wattage) and time (hours) on the efficiency of extraction was demonstrated and, through a stepwise approach, standard operating conditions defined that consistently resulted in the recovery of 75% (95% CI 63-85%) of all present off-host stages from any given soil sample. To extract off-host stages alive, potentially for consecutive laboratory bioassays, a low wattage (15-25 W) and short extraction time (4 h) will be required. The odds of finding off-host stages in indoor samples were 3.7-fold higher than in outdoor samples (95% CI 1.8-7.7). For every one larva outdoors, four (95% CI 1.3-12.7) larvae were found indoors. We collected 67% of all off-host specimen from indoor sleeping locations and the presence of off-host stages in these locations was strongly associated with an infected person sleeping in the room (OR 10.5 95% CI 3.6-28.4). CONCLUSION The indoor sleeping areas are the transmission hotspots for tungiasis in rural homes in Kenya and Uganda and can be targeted for disease control and prevention measures. The soil extraction methods can be used as a simple tool for monitoring direct impact of such interventions.
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Affiliation(s)
- Abneel K. Matharu
- Freie Universität Berlin, Institute for Parasitology and Tropical Veterinary Medicine, Berlin, Germany
- International Centre of Insect Physiology and Ecology, Human Health Theme, Nairobi, Kenya
| | - Paul Ouma
- International Centre of Insect Physiology and Ecology, Human Health Theme, Nairobi, Kenya
| | - Margaret M. Njoroge
- International Centre of Insect Physiology and Ecology, Human Health Theme, Nairobi, Kenya
| | - Billy L. Amugune
- International Centre of Insect Physiology and Ecology, Human Health Theme, Nairobi, Kenya
| | - Ayako Hyuga
- International Centre of Insect Physiology and Ecology, Human Health Theme, Nairobi, Kenya
| | - Francis Mutebi
- Makerere University, College of Veterinary Medicine, Animal Resources and Biosecurity, Kampala, Uganda
| | - Jürgen Krücken
- Freie Universität Berlin, Institute for Parasitology and Tropical Veterinary Medicine, Berlin, Germany
| | - Hermann Feldmeier
- Charité–Universitätsmedizin Berlin, Institute of Microbiology, Infectious Diseases and Immunology, Berlin, Germany
| | - Lynne Elson
- KEMRI-Wellcome Trust Research Programme, Centre for Geographic Medicine Research (Coast), Kilifi, Kenya
- University of Oxford, Centre for Tropical Medicine and Global Health, Oxford, United Kingdom
| | - Ulrike Fillinger
- International Centre of Insect Physiology and Ecology, Human Health Theme, Nairobi, Kenya
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Elson L, Nyawa SM, Matharu A, Fillinger U. Developing low-cost house floors to control tungiasis in Kenya - a feasibility study. BMC Public Health 2023; 23:2483. [PMID: 38087242 PMCID: PMC10714545 DOI: 10.1186/s12889-023-17427-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 12/06/2023] [Indexed: 12/18/2023] Open
Abstract
CONTEXT Tungiasis is a neglected tropical skin disease endemic in resource-poor communities. It is caused by the penetration of the female sand flea, Tunga penetrans, into the skin causing immense pain, itching, difficulty walking, sleeping and concentrating on school or work. Infection is associated with living in a house with unsealed earthen house floors. METHODS This feasibility study used a community-based co-creation approach to develop and test simple, locally appropriate, and affordable flooring solutions to create a sealed, washable floor for the prevention of tungiasis. Locally used techniques were explored and compared in small slab trials. The floor with best strength and lowest cost was pilot trialed in 12 households with tungiasis cases to assess its durability and costs, feasibility of installation in existing local houses using local masons and explore community perceptions. Disease outcomes were measured to estimate potential impact. RESULTS It was feasible to build the capacity of a community-based organization to conduct research, develop a low-cost floor and conduct a pilot trial. The optimal low-cost floor was stabilized local subsoil with cement at a 1:9 ratio, installed as a 5 cm depth slab. A sealed floor was associated with a lower mean infection intensity among infected children than in control households (aIRR 0.53, 95%CI 0.29-0.97) when adjusted for covariates. The cost of the new floor was US$3/m2 compared to $10 for a concrete floor. Beneficiaries reported the floor made their lives much easier, enabled them to keep clean and children to do their schoolwork and eat while sitting on the floor. Challenges encountered indicate future studies would need intensive mentoring of masons to ensure the floor is properly installed and households supervised to ensure the floor is properly cured. CONCLUSION This study provided promising evidence that retrofitting simple cement-stabilised soil floors with locally available materials is a feasible option for tungiasis control and can be implemented through training of community-based organisations. Disease outcome data is promising and suggests that a definitive trial is warranted. Data generated will inform the design of a fully powered randomized trial combined with behaviour change communications. TRIAL REGISTRATION ISRCTN 62801024 (retrospective 07.07.2023).
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Affiliation(s)
- Lynne Elson
- KEMRI-Wellcome Trust, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Dabaso Tujengane CBO, Watamu, Kenya
| | | | - Abneel Matharu
- Human Health Theme, International Centre for Insect Physiology and Ecology, Nairobi, Kenya
| | - Ulrike Fillinger
- Human Health Theme, International Centre for Insect Physiology and Ecology, Nairobi, Kenya.
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Elson L, Kamau C, Koech S, Muthama C, Gachomba G, Sinoti E, Chondo E, Mburu E, Wakio M, Lore J, Maia M, Adetifa I, Orindi B, Bejon P, Fillinger U. National prevalence and risk factors for tungiasis in Kenya. Infect Dis Poverty 2023; 12:85. [PMID: 37723532 PMCID: PMC10506256 DOI: 10.1186/s40249-023-01131-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 08/18/2023] [Indexed: 09/20/2023] Open
Abstract
BACKGROUND Tungiasis is a highly neglected tropical skin disease caused by the sand flea, Tunga penetrans, the female of which burrows into the skin, causing pain and itching. The disease occurs throughout South America and sub-Saharan Africa but there are few systematic data on national disease burdens. The tungiasis research community is keen to develop survey methods to fill this gap. Here we used a school-based, thorough examination method to determine the prevalence and risk factors for tungiasis in Kenya. METHODS We conducted the first nationally representative survey of tungiasis, including nine counties covering the major ecological zones of Kenya. A stratified multistage random sampling was used to select 22 primary schools from each of the nine counties and to select up to 114 pupils aged 8 to 14 years in each school. Pupils were examined thoroughly for tungiasis. Two surveys were conducted, the first between May and July 2021 and the second between October 2021 and April 2023 when pupils were also interviewed for risk factors. Mixed effect logistic regression models were used to test associations of independent variables with tungiasis using the school as a random effect. RESULTS The overall prevalence of tungiasis in the first survey was 1.35% [95% confidence interval (CI): 1.15-1.59%], and 0.89% in the second survey. The prevalence ranged from 0.08% (95% CI: 0.01-0.59%) in Taita Taveta county to 3.24% (95% CI: 2.35-4.44%) in Kajiado county. Tungiasis infection was associated with county of residence, male sex [adjusted odds ratio (aOR) = 2.01, 95% CI: 1.52-2.67], and lower age (aOR = 0.81, 95% CI: 0.75-0.88). For the first time we demonstrate an association with attending public schools rather than private schools (aOR = 5.62, 95% CI: 1.20-26.22) and lower socioeconomic status (aOR = 0.10, 95% CI: 0.03-0.33). Using a rapid screening method of the top of feet only, would have missed 62.9% of all cases, 78.9% of mild cases and 20.0% of severe cases. CONCLUSIONS Tungiasis is widely but heterogeneously distributed across Kenya. School-based surveys offer an efficient strategy for mapping tungiasis distribution.
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Affiliation(s)
- Lynne Elson
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.
- Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | | | | | | | | | | | | | | | | | | | - Marta Maia
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ifedayo Adetifa
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
| | - Benedict Orindi
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Phillip Bejon
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ulrike Fillinger
- International Centre for Insect Physiology and Ecology (Icipe), Nairobi, Kenya
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