New publication: Environmental and Household-Based Spatial Risks for Tungiasis in an Endemic Area of Coastal Kenya
New publication! I started working on this cool project on tungiasis (jiggers) with colleagues in Kenya and Japan way back in 2014. Today, I am happy to say that after much ado our work has finally seen the light of day, thanks to Nagasaki PhD student (and soon to be Dr.) Ayako Hyuga. It appears today in the journal Tropical Medicine and Infectious Disease (MDPI).
Environmental and Household-Based Spatial Risks for Tungiasis in an Endemic Area of Coastal Kenya
“#Tungiasis is a #cutaneous #parasitosis caused by an embedded female sand flea. The distribution of cases can be spatially heterogeneous even in areas with similar risk profiles. This study assesses household and remotely sensed environmental factors that contribute to the geographic distribution of tungiasis cases in a rural area along the Southern Kenyan Coast. Data on household tungiasis case status, demographic and socioeconomic information, and geographic locations were recorded during regular survey activities of the Health and Demographic Surveillance System, mainly during 2011. Data were joined with other spatial data sources using latitude/longitude coordinates. Generalized additive models were used to predict and visualize spatial risks for tungiasis. The household-level prevalence of tungiasis was 3.4% (272/7925). There was a 1.1% (461/41,135) prevalence of infection among all participants. A significant spatial variability was observed in the unadjusted model (p-value < 0.001). The number of children per household, earthen floor, organic roof, elevation, aluminum content in the soil, and distance to the nearest animal reserve attenuated the odds ratios and partially explained the spatial variation of tungiasis. Spatial heterogeneity in tungiasis risk remained even after a factor adjustment. This suggests that there are possible unmeasured factors associated with the complex ecology of sand fleas that may contribute to the disease’s uneven distribution.” #environmental #kenya #NTD #NeglectedTropicalDisease #parasitology #globalhealth #publichealth
Its always a thing to celebrate, getting these new papers out. This one covers a topic close to home. After years of doing global health work, I never thought I’d be doing domestic health and even less certain that I’d be covering topics just down the road from me.
Together with partners from Wayne State University (Health Urban Waters), UM-Dearborn and the University of Michigan Ann Arbor, we characterized the state of recurrent flooding in Detroit, MI and explore possible public health impacts. The article appears in the International Journal of Environmental Research in Public Health. This was extremely rewarding work.
Article is open access.
Household flooding has wide ranging social, economic and public health impacts particularly for people in resource poor communities. The determinants and public health outcomes of recurrent home flooding in urban contexts, however, are not well understood. A household survey was used to assess neighborhood and household level determinants of recurrent home flooding in Detroit, MI. Survey activities were conducted from 2012 to 2020. Researchers collected information on past flooding, housing conditions and public health outcomes. Using the locations of homes, a “hot spot” analysis of flooding was performed to find areas of high and low risk. Survey data were linked to environmental and neighborhood data and associations were tested using regression methods. 4803 households participated in the survey. Flooding information was available for 3842 homes. Among these, 2085 (54.26%) reported experiencing pluvial flooding. Rental occupied units were more likely to report flooding than owner occupied homes (Odd ratio (OR) 1.72 [95% Confidence interval (CI) 1.49, 1.98]). Housing conditions such as poor roof quality and cracks in basement walls influenced home flooding risk. Homes located in census tracts with increased percentages of owner occupied units (vs. rentals) had a lower odds of flooding (OR 0.92 [95% (CI) 0.86, 0.98]). Household factors were found the be more predictive of flooding than neighborhood factors in both univariate and multivariate analyses. Flooding and housing conditions associated with home flooding were associated with asthma cases. Recurrent home flooding is far more prevalent than previously thought. Programs that support recovery and which focus on home improvement to prevent flooding, particularly by landlords, might benefit the public health. These results draw awareness and urgency to problems of urban flooding and public health in other areas of the country confronting the compounding challenges of aging infrastructure, disinvestment and climate change.
Are dogs associated with infections by a skin burrowing flea in Kenya? Masanobu Ono and I with Kensuke Goto, Satoshi Kaneko, mwatasa Changoma just published a paper on #tungiasis in the journal Tropical Medicine and Health.
Most people haven’t heard of tungiasis, an ectopic skin disease caused by the skin burrowing parasite, T. pentrans. It causes itching, pain, is associated with serious secondary bacterial infections, gangrene, social exclusion and debilitation. It primarily afflicts the very young and very old and is found almost exclusively in the poorest parts of the poorest parts of the world. It fits the classic definition of a neglected tropical disease.
We explored associations of wildlife and domesticated animals with household level tungiasis in Kenya using a two stage complex sampling based survey in an area adjacent to a wildlife preserve.
Tungiasis is a ectopic skin disease caused by some species of fleas in the Tunga genus, most notably T. penetrans. The disease afflicts poor and marginalized communities in developing countries. Transmission of tungiasis comprises a complex web of factors including domesticated animals and wildlife. This research explores animal and environmental risk factors for tungiasis in an area adjacent to a wildlife reserve in Kwale, Kenya.
A two-stage complex sampling strategy was used. Households were selected from three areas in and around Kwale Town, Kenya, an area close to the Kenyan Coast. Households were listed as positive if at least one member had tungiasis. Each household was administered a questionnaire regarding tungiasis behaviors, domesticated animal assets, and wild animal species that frequent the peridomiciliary area. Associations of household tungiasis were tests with household and environmental variables using regression methods.
The study included 319 households. Of these, 41 (12.85%) were found to have at least one person who had signs of tungiasis. There were 295 (92.48%) households that possessed at least one species of domesticated animal. It was reported that wildlife regularly come into the vicinity of the home 90.59% of households. Presence of dogs around the home (OR 3.85; 95% CI 1.84; 8.11) and proximity to the park were associated with increased risk for tungiasis infestation in humans in a multivariate regression model.
Human tungiasis is a complex disease associated with domesticated and wild animals. Canines in particular appear to be important determinants of household level risk.
Is pollen associated with suicide? That’s the question we sought to answer. Pollen related allergic rhinitis is associated with depressive symptoms, discomfort, pain, sleep disruptions, isolation and reduced quality of life in people who have them. Our team, led by UM researcher Dr. Rachel Bergmans, set out to test associations of suicide mortality in Ohio with pollen exposures using data from Ohio’s vital records and a novel prognostic, model based raster of daily pollen counts from Dr. Allison Steiner’s team at UM’s College of Engineering.
We explored associations of suicide with exposure to four types of pollens and the paper can be found here (Open access for 50 days). Suicide is serious. Though the causes of suicide are complex, pollen allergies are associated with depressive symptoms, isolation, pain, discomfort and for some, complete debilitation. #suicide#pollen#epidemiology
Background Seasonal trends in suicide mortality are observed worldwide, potentially aligning with the seasonal release of aeroallergens. However, only a handful of studies have examined whether aeroallergens increase the risk of suicide, with inconclusive results thus far. The goal of this study was to use a time-stratified case-crossover design to test associations of speciated aeroallergens (evergreen, deciduous, grass, and ragweed) with suicide deaths in Ohio, USA (2007–2015).
Methods Residential addresses for 12,646 persons who died by suicide were linked with environmental data at the 4–25 km grid scale including atmospheric aeroallergen concentrations, maximum temperature, sunlight, particulate matter <2.5 μm, and ozone. A case-crossover design was used to examine same-day and 7-day cumulative lag effects on suicide. Analyses were stratified by age group, gender, and educational level.
Results In general, associations were null between aeroallergens and suicide. Stratified analyses revealed a relationship between grass pollen and same-day suicide for women (OR = 3.84; 95% CI = 1.44, 10.22) and those with a high school degree or less (OR = 2.03; 95% CI = 1.18, 3.49).
Conclusions While aeroallergens were generally not significantly related to suicide in this sample, these findings provide suggestive evidence for an acute relationship of grass pollen with suicide for women and those with lower education levels. Further research is warranted to determine whether susceptibility to speciated aeroallergens may be driven by underlying biological mechanisms or variation in exposure levels.
New chapter from myself in a Springer volume: “Access to Health Care in Sub-Saharan Africa: Challenges in a Changing Health Landscape in a Context of Development”
I wrote a chapter for “Health in Ecological Perspectives in the Anthropocene” edited by Watanabe Toru and Watanabe Chiho. I have no idea if they are related. Either way, my chapter “Access to Health Care in Sub-Saharan Africa: Challenges in a Changing Health Landscape in a Context of Development” occupies pages 95-106 in the volume.
Check it out, you can buy the book through Amazon for a cool $109, or just my chapter through the Springer site for $29 or you can simply write me and I’ll give you a synopsis.
Here’s the abstract for the book:
This book focuses on the emerging health issues due to climate change, particularly emphasizing the situation in developing countries. Thanks to recent development in the areas of remote sensing, GIS technology, and downscale modeling of climate, it has now become possible to depict and predict the relationship between environmental factors and health-related event data with a meaningful spatial and temporal scale. The chapters address new aspects of environment-health relationship relevant to this smaller scale analyses, including how considering people’s mobility changes the exposure profile to certain environmental factors, how considering behavioral characteristics is important in predicting diarrhea risks after urban flood, and how small-scale land use patterns will affect the risk of infection by certain parasites, and subtle topography of the land profile. Through the combination of reviews and case studies, the reader would be able to learn how the issues of health and climate/social changes can be addressed using available technology and datasets.
The post-2015 UN agenda has just put forward, and tremendous efforts have been started to develop and establish appropriate indicators to achieve the SDG goals. This book will also serve as a useful guide for creating such an indicator associated with health and planning, in line with the Ecohealth concept, the major tone of this book. With the increasing and pressing needs for adaptation to climate change, as well as societal change, this would be a very timely publication in this trans-disciplinary field.
I’m only a middle author, but I have a new publication out. After being involved in this, I will never eat mukimo (Kenyan mashed potato dish) ever again. Ever again.
First Report of a Foodborne Providencia alcalifaciens Outbreak in Kenya.
Shah MM, Odoyo E, Larson PS, Apondi E, Kathiiko C, Miringu G, Nakashima M, Ichinose Y.
Am J Trop Med Hyg. 2015 Jun 29. pii: 15-0126.
Providencia alcalifaciens is an emerging bacterial pathogen known to cause acute gastroenteritis in children and travelers. In July 2013, P. alcalifaciens was isolated from four children appearing for diarrhea at Kiambu District Hospital (KDH) in Kenya. This study describes the outbreak investigation, which aimed to identify the source and mechanisms of infection. We identified seven primary and four secondary cases. Among primary cases were four mothers who had children and experienced mild diarrhea after eating mashed potatoes. The mothers reported feeding children after visiting the toilet and washing their hands without soap. P. alcalifaciens was detected from all secondary cases, and the isolates were found to be clonal by random amplified polymorphic DNA (RAPD) fingerprinting. Our study suggests that the outbreak was caused by P. alcalifaciens, although no fluid accumulation was observed in rabbit ileal loops. The vehicle of the outbreak was believed to be the mashed potato dish, but the source of P. alcalifaciens could not be confirmed. We found that lack of hygiene, inadequate food storage, and improper hand washing before food preparation was the likely cause of the current outbreak. This is the first report of a foodborne infection caused by P. alcalifaciens in Kenya.
© The American Society of Tropical Medicine and Hygiene.
PMID: 26123962 [PubMed – as supplied by publisher]
New Publication (from me): “Insecticide-treated net use before and after mass distribution in a fishing community along Lake Victoria, Kenya: successes and unavoidable pitfalls”
This was was years in the making but it is finally out in Malaria Journal and ready for the world’s perusal. Done.
Insecticide-treated net use before and after mass distribution in a fishing community along Lake Victoria, Kenya: successes and unavoidable pitfalls
Peter S Larson, Noboru Minakawa, Gabriel O Dida, Sammy M Njenga, Edward L Ionides and Mark L Wilson
Insecticide-treated nets (ITNs) have proven instrumental in the successful reduction of malaria incidence in holoendemic regions during the past decade. As distribution of ITNs throughout sub-Saharan Africa (SSA) is being scaled up, maintaining maximal levels of coverage will be necessary to sustain current gains. The effectiveness of mass distribution of ITNs, requires careful analysis of successes and failures if impacts are to be sustained over the long term.
Mass distribution of ITNs to a rural Kenyan community along Lake Victoria was performed in early 2011. Surveyors collected data on ITN use both before and one year following this distribution. At both times, household representatives were asked to provide a complete accounting of ITNs within the dwelling, the location of each net, and the ages and genders of each person who slept under that net the previous night. Other data on household material possessions, education levels and occupations were recorded. Information on malaria preventative factors such as ceiling nets and indoor residual spraying was noted. Basic information on malaria knowledge and health-seeking behaviours was also collected. Patterns of ITN use before and one year following net distribution were compared using spatial and multi-variable statistical methods. Associations of ITN use with various individual, household, demographic and malaria related factors were tested using logistic regression.
After infancy (<1 year), ITN use sharply declined until the late teenage years then began to rise again, plateauing at 30 years of age. Males were less likely to use ITNs than females. Prior to distribution, socio-economic factors such as parental education and occupation were associated with ITN use. Following distribution, ITN use was similar across social groups. Household factors such as availability of nets and sleeping arrangements still reduced consistent net use, however.
Comprehensive, direct-to-household, mass distribution of ITNs was effective in rapidly scaling up coverage, with use being maintained at a high level at least one year following the intervention. Free distribution of ITNs through direct-to-household distribution method can eliminate important constraints in determining consistent ITN use, thus enhancing the sustainability of effective intervention campaigns.