Do stray dogs raise risk for human infections of a skin burrowing flea in Kenya?
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.
Pigs and jiggers: could wild swine be spreading the awful foot burrowing flea?
I wanted to go and see what this jigger thing was really about so I had my guys rent a car and we drove into Mtsangatamu town. Mtsangatamu (I still can’t pronounce it properly) lies along the edge of the Shimba Hills Wildlife Reserve and, according to my data, is a hot spot for tungiasis, or infections from the so called “jigger flea.”
It is a beautiful area. Filled with tropical trees and overgrowth, the landscape looks almost uncontrollable, despite the soil being so sandy that not a drop of water stands anywhere. The air is blistering hot.
People don’t get out here much, though the packed buses that pass by every few minutes indicate that the area isn’t entirely isolated. We drop off some gas for one of our drivers, who has to slowly fill his tank, drop by drop, with the tiniest of plastic funnels. Some development project should provide proper plastic funnels to these guys.
For some reason, we drive into the bush along a foot path, until we find ourselves wedged between a number of small pine trees. “We have to walk now,” I am told while I wonder why we drove this far anyway. Walking would have been easier.
We exit the car, walk through what a patch of neatly arranged trees. A tiny tree farm. I never see this in Western, ever. Coming out, we walk into a compound laid out in a manner wholly uncharacteristic of Kenya. A two story building sporting an upstairs patio complete with a winding staircase to the top, the place looked like the type of patchwork architecture that you associate with off-gridders in the US rather than Kenyan peasants.
“The Mighty Paraffee: If in need call XXXXXXXXXXX”
The Mighty Paraffee turns out to be a kid of about 24, chilling out in the shade. He built this place himself, installed power, has a guest room and an upstairs shower and toilet. His room is decorated with reggae stars and pictures of the saints. Indian music is blaring out of the building. I’ve seen creative interiors from reggae fans in Kenya, but this is something else. This kid should be in architectural school. He even made sure to place the building under a giant tree to keep it cool.
I never figure out what the family does for money and no one can tell me, but the mother is exceedingly proud.
No jiggers here. We walk on. After about a kilometer, we find a poor family sitting outside their house. Children aren’t in school and no one speaks any English indicating that none of them go.
Hassan (one or our workers) brings over a little girl and tells me to look at her feet. Fatuma is 10 years old and her feet are infested with jiggers. She says the don’t hurt much in the day, but they itch at night. Her brother apparently has them, too. Her mother and her aunt do not.
Everyone is barefoot and they all sleep in the same house. I’m wondering if there might be something about the skin which makes kids susceptible while adults are spared.
I notice a group of goats in a pen and start asking questions about animals.
Tungiasis is a zoonotic disease. It is passed from wildlife to domesticated animals to people who bring it into the household and infect their other family members. Or so it is though. Not many people have really explored the question sufficiently. Of course, this is why I’m here.
They have about 15 goats, a few chickens and I notice a young dog and a cat walking around. I ask if they ever notice whether the dog ever has jiggers. They say no.
“What kinds of wildlife do you see around here?” One of the kids was killed by an elephant last year. There are wild dogs and hyenas which come and try to get the goats. Wild pigs dig up the cassava at night.
Pigs. That has to be it. A big mystery has been why there is such a tight relationship between distance to the park and jiggers infections. Wild pigs come out of the forest, raid the fields of the locals and get water from the river, and then recede back into the darkness before morning. 5km is approximately the distance that a pig could feasibly travel and return home in one night.
Pigs travel through and around the compound, dropping eggs, they mature and are probably picked up by dogs, but are most likely picked up by kids walking in the bush. They then bring them back home and pass them on to their family members.
Hassan associates jiggers with mango flowers, but I probe him further and find that the flowers coincide with the very dry season, which could explain why pigs are making the trek to the river and why they prefer the fields since both water and food are probably scarce in the forest.
I have to send a student out to investigate this further.
An old man comes out. He looks nearly 90, but is mostly likely on 60 at most. He has arthritis in his back. He shows me his feet which are moderately infected, mostly only between the toes. He asks for medicine. I tell him I’ll send some along. He offers me some boiled cassava which I graciously take. My colleague refuses because there are no cashew nuts with it, but I suspect that he’s worried about getting sick. I become concerned.
We take some pictures and go.
On the way back, we run into an elderly lady. She’s sitting next to her husband, who is busy getting lit on homemade beer at 11 in the morning. She shows me her feet. The spaces around her feet are infested with jiggers. It must be horribly painful.
She points out that she doesn’t have a whole lot of feeling in her left foot. I notice that her skin in this area is clear; the bone is visible through her skin. I ask what happened. She says that she got bitten by a snake 40 years ago. She was pregnant. I ask her if the baby was ok. “The baby is standing there!”
I consider making a joke about a snake baby, but think better of it. I’m just amazed that both of them survived. The wound was horrible looking.
Somehow, we manage to pull ourselves out of the trees and move on. There are some baboons removing mites from one another on the road on the way back, and I take some pictures. My colleague is about to pass out from the heat. I offer to drive.
Ebola: we don’t have time to waste
Ebola is a cool disease. It transmits among fruit bats in the area in and around the Central African Republic. Apes live in and under the trees the bats live in and ingest their feces. Humans who ingest the apes pick up the virus when slaughtering the animal, or so some think. The truth is that no one really knows for sure.
Contacts between humans is increasing as settlements expand and a demand for meat increases. Lacking access to formal methods of employment, individual sellers happily take advantage of market demand and a thinly profitable trade in bushmeat profulgates. Meat equals success and in the place of professionally or pastorally raised beef, which is mostly unavailable to poor people in countries like Liberia and Sierre Leone, people eat the monkeys, chimps and many other of our cousins which are able to harbor the many of the same pathogens we do.
One person gets sick. He or she has no access to formal care because his or her government can’t or won’t provide it so he remains at home. The family consults the local herbalist who provides some medications which offer temporary psychological relief but nothing more. As time ticks on, the victim becomes even sicker until the situation becomes so serious that the family has no choice but to carry their dying loved one to a health clinic 20 km away from their house. Along the way, everyone carrying him or her touches infected feces and vomit and three weeks later the process is repeated.
This could have all been avoided if rural economies were developed enough so that a mass migration to urban areas wasn’t necessary, had there been safer sources of meat available for an affordable price, were there sufficient jobs which wouldn’t necessitate the bushmeat trade, were the governments of Liberia and Sierre Leone effective enough to place a proper health facility close by to patient 0’s house and if health care was dependable enough to be able to spot and deal with an Ebola case.
Ebola is a conflation of ecology, economics, sociology, culture and politics, all mixed together to create conditions for one of the worst health crises the African continent has seen since HIV. It’s going to erase any of the gains of the past decade and collapse the already struggling health systems of some of the poorest places on the planet.
Meanwhile, the United States is having another 9/11 moment and this is where I’m starting to get quite concerned. Panic is about to become policy. Fears of global terrorism prompted our entry into Afghanistan, which might have been justified. But it also paved the way for the invasion of Iraq, which, from the beginning, was a disaster waiting to happen. Out of 9/11, we got the Patriot Act, a massive expansion in government powers to search, seize and detain and America stood by and allowed it to happen with little debate.
I am not a Libertarian, though keep getting accused of being one. I believe in public schools, public health care and government oversight of dangerous industries. So there. John Galt wouldn’t be much into me (but I guess from the far, far left anyone looks like a Libertarian).
I am, however, despite my leftist pedigree, quite concerned with the rights of individuals and the potential for panic and ignorance to lead to a rhetoric that can quickly spiral out of control and veer seemingly caring people away from the direction that the moral compass would normally point us in. I am remembering how many Americans supported torture during Bush II and wondered how many of them would support torture were it to be practiced on their own children. Though seemingly alarmist, I think that we need to be extremely careful.
Enough about me. The reality of Ebola is that it is a man-made crisis. Forest dwelling locals have eaten bushmeat for as long as humans have lived there but there is little evidence that there has ever been a large scale outbreak like the one we are currently experiencing (though history in Africa is often obscure). As I noted earlier, many forces are at play, all of which are associated with the rapid social change that Sub-Saharan African states are currently experiencing.
Some of these forces are inevitable. Population growth, as it did in Europe and Asia before, has led to the creation of mega-cities. The connections, however, between the rural and the urban, however have not been severed. People are going to do what they do, regardless of risk, particularly if they can make a buck meeting some market demand.
Some forces, though, are avoidable. While health care did not initiate the crisis, it helped drag it along. Liberia and Sierre Leone can boast to have two of the worst health systems in the world, but their poor capabilities are hardly unique in Sub-Saharan Africa. NGOs and missionary groups work to plug some of the gaps, but the reality is that without a concerted and proactive effort from the governments of those countries, the system will never improve. International funding is too poor and weak national economies and top heavy tax structures can’t adequately fund these systems domestically. Poor funding leaves many clinics, particularly those in rural areas where these outbreaks begin, without supplies, trained staff and diagnostic equipment. In Kenya, Malawi and Tanzania, I’ve seen more than one rural clinic without power or clean water. Worse yet, Ebola outbreaks, though devastating, are infrequent so that more pressing needs like malaria, diarrheal disease and HIV eat up the brunt of the already scarce funds clinics receive. Pathogens not only compete in the wild, but also for funding and support. This leaves many rural health workers without the protective gear they need, so that they work are the highest risk for death from diseases like Ebola.
What can we do? First, we can calm down. In the United States, the reality is that one of far more likely to be killed by an oncoming car than from Ebola and the probability of sustained transmission extremely low. Though people like to view domestic transmission events such as the one in Texas as failure, the reality is that public health and medical resources move much more quickly and effectively in Texas than in troubled Liberia. Much is made over Ebola’s lethality, but a patient who is found to be infected in the United States has a vastly higher likelihood of surviving than one in Liberia.
Second, leaders can stop spreading and capitalizing on misinformation. While attractive, promoting hysteria only leads to bad policy. The tendency in America is to view as some kind of apocalyptic movie scenario. While fun (not to me), the reality is that there are people in the world who are dying who shouldn’t be. Moreover, closing schools because someone knows someone who knows a Liberian is just simply unwise and counterproductive in the long term.
Third, the international community needs to engage the governments of Liberia and Sierre Leone to improve their public health infrastructure. This is not an easy task. The histories of working relationships of international health bodies and developing countries governments are fraught with failure. Mutual distrust, corruption and indifference of political leaders to the plight of their constituencies has created a mostly untenable system. However, providing supplies and training come at little cost is a mostly uncontroversial affair.
How long will this last? No one knows but it is inevitable that, even if this epidemic is brought under control, it certainly won’t be the last of its kind. We don’t have time to waste.
The Jigger flea: a neglected scourge
Tunga penetrans is native to South America, was brought to West Africa through the slave trade. In the mid 19th century it was brought on an English shipping vessel and made its way through trade routes and is now found everywhere throughout the continent.
Bacteria opportunistically invades the site and super-infections (multiple pathogens) are common. Victims suffer from itching and pain and multiple fleas are common. Due to the location of the bite, people often have trouble walking and due to the disgusting nature of the infection, victims are stigmatized and marginalized. Worse yet, the site can becomes gangrenous and auto-amputations of digits and feet and eventually death are not uncommon.
The Parliaments of both Kenya and Uganda have introduced bills in the past calling for the arrest of people suffering from jiggers. Of course, these ridiculous bills don’t come with public health actions to control the disease.
Jiggers are entirely preventable, treatable through either surgical excision or through various medications but risk factors for it are mostly unknown and the data contradictory and mostly inconclusive.
It sometimes occurs in travelers and is easily treated in a clinic on an outpatient basis but is a debilitating infection for poor communities. Thus, it is not taken seriously by international public health groups who choose to focus on big issues like HIV and malaria.
Jiggers are a classic example of the neglected tropical disease: it devastates the poorest of the poor but gets almost no attention from donors or the international press.
We gathered some data on jiggers back in 2011 along the coast of Kenya. Without presenting these results as official, I was drawn to the attached map.
Animals of various species have been implicated as reservoirs for the disease, most notably pigs and dogs. Less understood is the role of wildlife in maintaining transmission. On the map below, the large yellow dots represent cases. Note that they are nearly all located along the Shimba Hills Wildlife Reserve. I calculated the distance of each household to the park’s border (see the funny graph at the bottom), and found a graded relationship between distance and jiggers infections. Past 5km away from the park, the risk of jiggers is nearly zero.
What does this mean? I have ruled out domesticated animals, at least as a primary reservoir. People in this area tend to all own the same types and numbers of animals. Being Islamic, there are no pigs here, but dogs are found everywhere. Despite this, there are distinct spatial patterns which are associated with the park. Note that all of the cases are found between the parks border and a set of lakes, perhaps implying that certain wild animals are traveling there for water and food.
The ecology of jiggers is very poorly understood and, like many pathogens (like Ebola, for example), wildlife probably play an important role.
It’s worth paying me a lot of money to study it.
Sick animals in Gembe East
I went on a hunt for some sick animals… and finally found some! We were visiting some families in Gembe East, and area close to Mbita Point in Homa Bay County and found a man who had more than 50 goats and nearly 20 cows. In Maasai-land, that’s a tiny herd, but in Luo-land, its gigantic.
He had a sickly goat which had just aborted, vaginal discharge, was feverish, emaciated and had a hard coat. A friend suggested it might be Brucella, but without a test, we’ll never really know. Either way, I suggested that it might not be a terrible idea to make choma out of it (as he said he was going to do) and get it away from the pregnant lady in the house. He reported that there had been a couple of other abortions in his herd.
The cows in Luo-land don’t look very good. It’s possible that the scant rains recently are having an impact on the vegetation. Pink-eye is everywhere right now.
So much is made about potentially zoonotic diseases in giant pastoralist herds, but the issue goes mostly ignored around Lake Victoria. Though animal possession per household is low, there are more households living in more densely populated conditions, meaning that there are potentially more animals per square kilometer in Nyanza than in Northern Kenya.
A combination of high human and animal density, poverty and a shared water source could create perfect conditions for a zoonotic disease outbreak.
Yesterday, someone gave me a live chicken
We were having choma with the chief of the area a few weeks ago, and we came up with the idea of having a regional soccer match. Yesterday was the first meeting of the planning committee. (Turns out that putting on a soccer match is like setting up a punk show, except that people will probably turn out.)
We discussed the particulars of the football match, and then ate a great chicken dinner from the chief’s mother. We also met the chief’s father, an 87 year old ex-school teacher who had his last child 12 years ago and learned of that gentleman’s mother who died two months ago at the incredible age of 105. In an area where the average life expectancy hovers just around 40, these are some tough people indeed.
After eating, we went and checked out the soccer pitch, which has an amazing view of Lake Victoria and some nearby mountains. It’s going to be a great day.
The roads out there are terrible. I was getting sea sick on the way back, when the guys in the car suggested that we go an visit on of our staff members. I reluctantly said ok since I was just hoping to get out to the main road as quickly as possible. (Plus the Iran/Argentina game was about to start.)
We arrived to his house and it was already dark. The staff guy is there standing outside holding a radio. His wife looks like she’s just come from church.
Everyone suddenly jumps out of the car and proceeds to run around greeting one another. I talk to the staff guy for a moment. He’s exceedingly friendly but looks somewhat impatient. I figure out that the radio means that he’s waiting for the game to begin.
Silas (another staff member) asks me if I like watermelon. I say yes, and the wife comes up behind me and puts a live chicken in my hands. “This one will be very sweet” comes out in a really confident, educated brand of English that’s somewhat uncharacteristic of the area.
I’m not sure what to do. I’ve never held a live chicken before. I say thank you and carry it over to the car and put it in the back with the watermelons. We quickly say thank you, get in the car and drive on.
On the way back, I have to keep making sure that the chicken doesn’t get crushed by a rolling melon. After we get home, we put the chicken in a box and set it in the food pantry with some corn and rice.
We’ve resolved to have the house lady transform the chicken into dinner tomorrow, which gets me off the hook, because I have no idea how to do such things.
Can the use of technology in surveys change the nature of responses?
In the past, surveys were done on paper, either through a designed questionnaire or by someone frantically writing down interview responses. When computers came around, people would be hired to type in responses for later analysis.
Nowadays, with the advent of cheap and portable computing, research projects are rapidly moving toward fully digital methods of data collection. Tablet computers are easy to operate, can be cheaply replaced, and now can access the internet for easy uploading of data from the field.
Surveyors like them because large teams can be spread out over a wide space, data can be completely standardized and the tedious process of data entry can be avoided.
Of interest to me, however, is whether the technology is influencing the nature of the responses given. That is, will someone provide that same set of responses in a survey using digital data collection methods as in a paper survey?
Recently, we attempted using a tablet based software for a small project on livestock possession and management on Mbita Point in Western Kenya. I intended it as a test to see if a particular software package might be a good fit for another project I`m working on (the one that`s paying the bills).
We had only limited success. The survey workers found the tablets clunky and a number of problems with the Android operating system made it more trouble than the survey was actually worth. Of interest, though, was how the technology distracted the enumerators from their principle task, which was to collect data.
Enumerators would become so wrapped up in trying to navigate the various buttons and options of the software that they couldn`t effectively concentrate on performing the survey. Often they appeared to skip questions out of frustration or would just frantically select one of the many options in the hope of moving on to the next one.
In a survey of more than 100 questions, the process started taking far more time than households were willing to give. We eventually had to abandon the software and revert to a paper based method.
Surveys went from lasting more than one hour, to taking under 30 minutes. Workers were more confident and had more time to interact with the respondents. Respondents had more of an opportunity to ask questions and consider the meaning of what they were being asked. They offered far more information than we expected and felt that they were participating in the survey as a partner and not just as a passive victim.
One of our enumerators noted that people react differently to a surveyor collecting data on the tablets than with paper. She described collecting data with technology as being “self absorbed” and alienating to the respondents. Collecting data on paper, however, was seen as a plus. “They can see me writing down what they say and feel like their words are important.”
I`m thinking that the nature of the responses themselves might be different as well. Particularly with complex questions of health and disease, often the surveyors will have to explain the question and give a respondent a chance to ask for further clarification. Technology appears to inhibit this process, perhaps compromising the chance for a truly reasoned response.
While I am absolutely not opposed to the use of technology in surveys, I think that the survey strategy has to be properly thought through and the challenges considered. At the same time, however, data collection is a team effort and requires a proper rapport between community members and surveyors who often know each other.
Is technology restricting our ability to gather good data? Could the use of technology even impact the nature of the response by pushing them in ways which really only tell us what we want to believe rather than what actually exists?
New insurance product protects pastoralists from losses due to drought in Kenya
This is rather interesting. Pastoralism is characterized as a complex system of avoiding, accounting for and taking advantage of risk, not unlike hedge fund managers in the United States. Animals represent potential earnings, prices at markets vary with grazing conditions and perceived long term benefits, and decisions to sell animals are not made lightly.
In the past, pastoralists have protected against devastating losses through herd maximization and cooperation and conflict over prime grazing spots, along with systems of redistribution where animals from wealthy herders are given away or stolen with the approval of the community. The world has become complicated, though, as droughts become more and more frequent, political borders and conflicts constrain the movements of pastoralists, and as the spear has been replaced with the AK-47.
An interesting though appropriate insurance system might help to mitigate losses and stabilize communities.
Brucellosis creates political uproar over Yellowstone bison herd
Bison were once found across most of the middle and western United States and Canada, but were nearly hunted to extinction in the 19th century. Expansionists sought to cut off Native American food supplies and the Industrial revolution created an intense demand for buffalo hides, which were used for belts to run large machinery.
Fortunately, a few conservationists saved the fewer than 25 animals who remained in the wild in Yellowstone Park. In 1902, captive bison were introduced into the park to increase the genetic viability of the herd. Populations were managed and regulated until 1966 after which the herd was allowed to expand naturally.
However, climate change and food scarcity has caused some of the expanding population to move out of the park in search of grazing lands.
This is a real problem for cattle herders. Bison are thought to be the largest reservoir of Brucellosis in the United States, despite decades of effort to eliminate the disease. When bison roll into cattle ranches, bacteria can spread from bison to cattle.
Bison appear to suffer little from the disease, but in cattle, spontaneous abortions are likely, resulting in major economic losses to livestock producers. When cattle test positive for the disease, they are culled immediately. The US government compensates the farmer for the loss.
Bison who leave the park and wander into neighboring Montana threaten the state’s Brucella free status. If Montana were to lose that status, all cattle exported from Montana would have to be tested and certified Brucella free, which would increase costs to livestock producers.
Park managers have considered culling the herd, and reducing its size to a more manageable 3000 animals. They propose killing several hundred of the animals which are in the vicinity of Montana’s border as both a precaution and a way to scale back the bison population. The carcasses will be sold as meat.
And this is where environmentalists come it. Several organizations have sprung up around the issue. Most notably, a man chained himself to a 55 gallon drum filled with concrete to prevent more bison from being killed and shipped off the slaughter. Hoping to avoid an escalating political confrontation, the authorities called off the cull.
Opponents of the cull claim that Yellowstone can support more than 6000 bison, far over the target population size of 3000. Proponents argue that the park may theoretically support more than 3000, but a larger herd means that it is more likely that bison will wander into Montana in search of food. The risk there, of course, is that Brucella will be brought into Montana. It is conceivable (to me) that this whole row wouldn’t exist without Brucellosis.
I’m especially interested in the issue because it parallels similar problems in Laikipia, Kenya. Livestock producers and conservationists are constantly in conflict over issues of land rights, economic impacts of disease threats, the rights of wildlife and strategies to protect it in increasingly crowded and rapidly changing areas of the world.
Given the very different perspectives of conservationists and ranchers, no solution has been found in Kenya yet. I’m doubting that one will be found in Yellowstone. Environmentalists are taking this as a moral issue (save the bison!), conservationists are approaching this as a practical issue (manage the herds properly and stay out of the political debate) and herders speak to economic issues (Brucella threatens my business).