New publication: An urban-to-rural continuum of malaria risk: new analytic approaches characterize patterns in Malawi
12 years in the making! Our new paper from partners at the University of Michigan and the #Malawi College of Medicine on new approaches to defining urban and rural environments in the context of malaria risk is now out in #Malaria Journal.
It was the last chapter in my dissertation to be published (all the rest were published when I was still in grad school.)Short version: malaria is complicated and really local. Malaria transmits poorly in urban and environments and well in rural environments. There’s urban like spaces in “rural” areas and rural-like spaces in “urban” areas, demanding a more nuanced view of what those terms really mean.
We know that malaria is a “rural” problem, but not all “rural” spaces are the same. Even in the country, there are “urban like” spaces and in “rural like” spaces even in the largest cities in Sub-Saharan Africa. Could those spaces impact malaria risk? If so, shouldn’t we redefine what we mean by urban vs. rural to inform intervention strategies to better target resources?
Here, we combine GIS and statistical methods with a house to house malaria survey in Malawi to create and test a new composite index of urbanicity and apply that to create a more nuanced risk map.
The urban–rural designation has been an important risk factor in infectious disease epidemiology. Many studies rely on a politically determined dichotomization of rural versus urban spaces, which fails to capture the complex mosaic of infrastructural, social and environmental factors driving risk. Such evaluation is especially important for Plasmodium transmission and malaria disease. To improve targeting of anti-malarial interventions, a continuous composite measure of urbanicity using spatially-referenced data was developed to evaluate household-level malaria risk from a house-to-house survey of children in Malawi.
Children from 7564 households from 8 districts in Malawi were tested for presence of Plasmodium parasites through finger-prick blood sampling and slide microscopy. A survey questionnaire was administered and latitude and longitude coordinates were recorded for each household. Distances from households to features associated with high and low levels of development (health facilities, roads, rivers, lakes) and population density were used to produce a principal component analysis (PCA)-based composite measure for all centroid locations of a fine geo-spatial grid covering Malawi. Regression methods were used to test associations of the urbanicity measure against Plasmodium infection status and to predict parasitaemia risk for all locations in Malawi.
Infection probability declined with increasing urbanicity. The new urbanicity metric was more predictive than either a governmentally defined rural/urban dichotomous variable or a population density variable. One reason for this was that 23% of cells within politically defined rural areas exhibited lower risk, more like those normally associated with “urban” locations.
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.
Among other things. Check out the full interview here:
The risks of covid19 are well known at this point. While we all need to be sympathetic to the need for people to earn a livelihood, a living should not come at the expense of public health and worker safety. This should be a given.
I have seen some businesses who are doing quite well right now. While my sample size is certainly small and my observations subject to my own biases, it is easy to tell apart the businesses who make an effort and the ones who do not.
We should support businesses who 1) require masks without fail, 2) offer masks and gloves to both workers and customers, 3) limit the number of customers in the store at any given time and 4) build plexiglass shields to separate customers and workers.
We should not support businesses who take a lax approach to masks, do not offer masks to customers who don’t have them, allow large numbers of people in the store proportional to size and do not have plexiglass shields in front of the register.
All of these modifications are easy and cheap to implement. There are few occasions where there is any valid excuse for not doing all of them in normal retail and food service industries.
Which bring me to the the point of this post. How can customers know how seriously businesses are taking covid19? Certainly, online review sites like Yelp or Google are going to be helpful, but these do not provide any indication of progress that businesses might make (“evolution”) or provide standards so that we can easily compare one business with another.
Many municipalities provide public record of compliance with health regulations. The New York City Health Department performs unannounced inspections of all restaurants in the five boroughs at least once an year and makes the data public. The public can search for any food provider in the city for any type of violation and even has a grading system. The Washtenaw County Health Department and the Michigan Department of Agriculture and Rural Development conduct regular inspections of food service establishments within their jurisdictions and publish the results online. The worst offenders often make the papers.
We need such a system for all businesses to make sure that they comply with efforts to contain the spread of covid19. Consumers have a right to know whether a business is compliant or not BEFORE they make the decision to visit that business. While the logistics of such a system are complicated and likely expensive, they are necessary.
Will this be on our legislature’s agenda? Do local health departments already have the authority to implement such a system? Would businesses push back against cheap masks and plexi? Certainly, there are challenges to implementation, but it isn’t impossible.
A friend of mine hooked me up with a short gig teaching a course in malaria and tropical medicine for Colby College’s JanPlan. Every January, students have the opportunity to study a subject in depth, often with teaching faculty not based at Colby College.
I have long wanted to design an undergrad level course in tropical medicine so took it as an opportunity to do so. We focused mostly on malaria, covering the basics of malaria epidemiology, pathogen and vector biology, prevention and treatment, diagnostics, vector control, health care delivery, international funding for malaria programs, drug and insecticide resistance and elimination/eradication. We even had lectures on basic concepts of epidemiology and infectious disease and talked at length about public health, public health practice and medical ethics. It has been a fairly intense month.
At first, I was a bit concerned that the subject matter would be too broad, particularly for science people, but quickly learned that much of the class were non-science majors, and most were freshmen. This gave me a great opportunity to bring in a wide range of topics that could appeal to just about everyone in the class.
I found this great post on drug shortages that appeared in BMJ today. Among all of the other great gems in it, was this incredibly interesting article on the creation of a mechanical bloodletting device. Jean-Baptiste Sarlandière, a French anatomist and inventor, created the “mechanical leech”, a device intended to extract a controlled amount of blood from the body. Sarlandiere intended the device to replace leeches, which were subject to increasing demand, were becoming expensive, were difficult to cultivate, and were subject to shortages in the Netherlands, who was a large producer of leeches at the time.
A paper was written on the device back in 2009, and within there is a dataset of leech imports and exports to France, which includes data on the monetary value of leeches and public consumption. Of course, I couldn’t resist pulling this data out and doing something with it (despite having better things to do.)
Here is the data, pulled from yet another paper (Alexandre E Baudrimont, Adolphe J Blanqui, et al., Dictionnaire de l’industrie manufacturie`re, commerciale et agricole, Paris, J-B Baillière, 1833–1841, pp. 25–30.):
|Year||Number of leeches imported||Value in Francs||National consumption||Exports||Import export ratio||Value per leech|
Of course, I am fascinated with this. The number of leeches exported from France rose during this period as did the market price of each leech. Though the entire industry would eventually collapse because other medical advances of the nineteenth century would supercede it, it is clear that increased demand and expense led to innovation to create devices to replace it. I don’t know whether the “mechanical leech” led to the development of other medical devices, but would like to think that even batshit ideas like how swamp worms draw out blood to cure any and all medical conditions would lead to the creation of methods which do improve health.
I started this blog way back in 2007, when I was a Masters student at the University of Michigan. At the time, it felt like a good way to get writing out there, and communicate ideas in a public forum. When I was at my peak on this blog (and my life, it seems) I was writing daily, sometimes posting the data analyses equivalent to many (low quality) published scientific papers, writing travel logs, doing interviews, broadcasting psychological traumas, posting photos… it was a good time.
At some point, I lost focus, got busy with other things, got on the wrong track, the right track, it really isn’t clear to me what happened, but I posted less and wrote less. The result was that my writing suffered, because the daily posts provided a great opportunity to keep my writing in shape, and explore interesting scientific topics in depth without worrying about the bureaucratic demands of peer review or research collaborators. While peer review and research collaborations are important, every science needs a forum with which to explore ideas.
Now, though, as I move back into my academic career, I am wondering…. is blogging worth it anymore? I just read Rachel Strohm’s final post . Rachel started blogging about the same time I did, and has since moved on to a fruitful career in development and academia and now lives in Kenya. She has recently stopped blogging, noting that “The development blogging ecosystem is basically dead. ” (I do wonder if her move to Kenya might have killed her motivation for blogging, the same way it killed mine.) I have also noticed that the authors of several blogs I used to read have also moved on.
Strohm offers that direct newsletter updates and Twitter might be a better platform for dissemination blog-like information for people. I think Twitter is a pretty terrible platform for anything at all outside of haranguing right wingers or sending cat videos, so I am not sure that it would do what blogging would have done for me. While I do not have a large Twitter presence, it seems to be a major time suck, with little reward and multiple costs (like blood pressure.)
Newsletters are interesting. Even as a musician, I find that directly engaging people who might be interested in my music is far better than any of the social media platforms, which do their best to make sure that no one ever sees what you do, unless you have a thousand dollar PR budget.
I liked the blogging format. I still do. I think it could still work, but wonder…. do people even read long form writing anymore? Does it have any impact? Is blogging going the way journalism is? What is a good platform anymore? Does writing mean anything at all anymore?