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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

New paper out: “Indoor apparent temperature, cognition, and daytime sleepiness among low-income adults in a temperate climate”

New paper out! I’m really proud to have been a part of this research, now published in Indoor Air (Wiley)

We put temperature monitors in 34 low income Detroit homes and tested to see if high temperatures had anything to do with daytime sleepiness or word recall. 

“The burden of temperature-associated mortality and hospital visits is significant, but temperature’s effects on non-emergency health outcomes is less clear. This burden is potentially greater in low-income households unable to afford efficient heating and cooling. We examined short-term associations between indoor temperatures and cognitive function and daytime sleepiness in low-income residents of Detroit, Michigan. Apparent temperature (AT, based on temperature and humidity) was recorded hourly in 34 participant homes between July 2019-March 2020. Between July-October 2019, 18 participants were administered word list immediate (WLL) and delayed (WLD) recall tests (10-point scales) and the Epworth Sleepiness Scale (24-point scale) 2–4 times. We applied longitudinal models with nonlinear distributed lags of temperature up to 7 days prior to testing. Indoor temperatures ranged 8–34°C overall and 15–34°C on survey days. We observed a 0.4 (95% CI: 0.0, 0.7) point increase in WLL and 0.4 (95% CI: 0.0, 0.9) point increase in WLD scores per 2°C increase in AT. Results suggested decreasing sleepiness scores with decreasing nighttime AT below 22°C. Low-income Detroit residents experience uncomfortably high and low indoor temperatures. Indoor temperature may influence cognitive function and sleepiness, although we did not observe deleterious effects of higher temperatures.”

New publication: Recurrent home flooding in Detroit, MI 2012-2020

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.

Abtract:

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.

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.

Abstract:

Introduction
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.

Methods
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.

Results
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.
Conclusions

Human tungiasis is a complex disease associated with domesticated and wild animals. Canines in particular appear to be important determinants of household level risk.

#research#science#publichealth#medicine#health#environmental#ntds#neglectedtropicaldiseases#poverty#parasitology#globalhealth#healthdisparities

My Children are Seven in Number

WYTfXNot sure why but for some reason over lunch I got interested in old labor songs. This one was particularly bleak. Apparently, it is intended to be sung over “My Bonnie Lies Over The Ocean.” As our administration erodes labor and environmental protections for the inexplicable sake of bringing back coal mining, it pays to have a look back at how bad it really was.

Song: My Children are Seven in Number
Lyrics: Eleanor Kellogg(1)

Music: to the tune of “My Bonnie Lies Over the Ocean”
Year: c.1933
Genre:
Country: USA

 

My children are seven in number,
We have to sleep four in a bed;
I’m striking with my fellow workers.
To get them more clothes and more bread.

CHORUS:
Shoes, shoes, we’re striking for pairs of shoes,
Shoes, shoes, we’re striking for pairs of shoes.

Pellagra(3) is cramping my stomach,
My wife is sick with TB(4);
My babies are starving for sweet milk,
Oh, there as so much sickness for me.

Milk, milk, we’re striking for gallons of milk,
Milk, milk, we’re striking for gallons of milk.

I’m needing a shave and a haircut,
But barbers I cannot afford;
My wife cannot wash without soapsuds,
And she had to borrow a board.
This song was originally posted on protestsonglyrics.net
Soap, soap, we’re striking for bars of soap,
Soap, soap, we’re striking for bars of soap.

My house is a shack on the hillside,
Its doors are unpainted and bare;
I haven’t a screen to my windows,
And carbide cans do for a chair.

Homes, homes, we’re striking for better homes,
Homes, homes, we’re striking for better homes.

They shot Barney Graham(5) our leader,
His spirit abides with us still;
The spirit of strength for justice,
No bullets have power to kill.
This song was originally posted on protestsonglyrics.net
Barney, Barney, we’re thinking of you today,
Barney, Barney, we’re thinking of you today.

Oh, miners, go on with the union,
Oh, miners, go on with the fight;
For we’re in the struggle for justice,
And we’re in the struggle for right.

Justice, justice, we’re striking for justice for all,
Justice, justice, we’re striking for justice for all.

Snake Bites in Kwale, Kenya: Into the Field

snakebitesWe just spent the day driving around Kwale looking for snakes, and/or people who had been bitten by snakes. As the last post showed, snakebites are a persistent problem along the Kenyan Coast, with more then 5% of the households we survey indicating that at least one person in the household had been bitten in the past two years.

It wasn’t difficult to find them.

Snakes are universally feared all over Africa and the associations with witchcraft make it a common topic of discussion. Everyone knows someone who has been bitten. They often know all the details, including where it happened and what occurred following the bite. It’s never a happy story.

We went deep into Kinango, an extremely rural area west of Kwale Town and found a friendly lady who seemed to know everything about everyone. She was incredibly jolly, pulled out some plastic chairs for us to sit under and cracked jokes the whole time. I even got to copy her collection of Sangeya music which she had recorded on her phone (another post but you can hear some of it here) at some local music festivals. In total I got more than five hours of live Sengeya and Chilewa music. In the music world, these would be called “field recordings.” Here, this is just music she cooks and cleans to.

Switching back and forth between snakes and Sengenya (in Africa it seems to be possible to have multiple conversations at once), she told us about a kid who had been bitten two days previous. She even told us where to find her, so off we went.

The child was collecting firewood around a mango tree near her home, when she was suddenly bitten by a large green snake, not once but three times on the foot. The snake bit once skated away, decided it wasn’t enough and came back and bit her twice more.

Ants had moved into the dead tree and hollowed out the area underneath. Presumably, the snake moved in previously and came out to warm up during the day.

The mother thankfully took the child immediately to Kinango Hospital and treated was administered. The child was given a three day course of antivenom injections and charcoal was wrapped around the wounds to absorb any venomous discharge. Though the child complains of some numbness in the area, it looks as if there won’t be any permanent damage. Thankfully.

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Snake bite (species unknown). Note the charcoal. Victim is a 10 year old girl.

We were also told of an old woman who had been bitten more than 20 years ago, and was badly scarred, figured out where she was and off we went again.

As we pulled up a friendly young lady came out to greet us, and showed us the way to the house out back. In the distance, we could see an old lady walking with a limp. Otherwise, she was completely fit and seemed to be cutting her own firewood with a panga.

She brought us out some chairs and sat down to chat. In 1992, she had been out back collecting firewood (a pattern) and was bitten on the foot by puff adder, one of the deadliest snakes in the world. She was bitten on the foot, and became immobile for nearly a week. A series of witch doctors were brought in, who administered charcoal rubbed into small cuts in the skin.

Necrosis set in, and watery blood erupted out of the wound site. A large number of maggots appeared. Finally, someone had the good sense to take her to the hospital, where she spent an entire year.

The details were unclear, but it appeared that the gangrene was so severe that multiple infections were presents. They likely had her on intravenous antibiotics for an extended amount of time. Despite this, the foot did not heal. Some Christian missionaries came, and convinced her to convert to Christianity, which, she claimed, improved her condition. This is likely coincidental.

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Puff Adder wound. Note the permanent curvature of the foot. She continues to have to wrap it and use topical medication, 24 years following the bite.

The doctors suggested a skin graft to improve the foot, but she refused. Necrosis was so deep that it permeated the bone and the foot is permanently curved as a result. The leg still shows sign of swelling even more than 24 years after the bite. In most cases, they probably would have simply amputated.

The lady was born in 1948, bore ten children, one of which was born just as she was bitten. She was unable to breast feed or care for the child. Regardless, the daughter has two children of her own now.

Snakebites are bad news. In this woman’s case, the disregard for proper medical care simply made a bad situation worse. She is truly lucky to be alive. If she had died, it is doubtful that the Mgangas would have admitted any responsibility.

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Puff Adder victim, born in 1948. Ten kids. Still going strong.

Links I liked January 23, 2015

Measles cases by yearSome public/global health things that caught my eye today:

1. A visit to the most sickest town in America, a coal mining town in Virginia. Dear Republicans, pay for health care now and abandon “clean coal” or pay more later. It’s up to you. (The Atlantic)

2. How paid sick leave could boost American productivity. (CEPR)

3. Dealing with antibiotic resistance is going to take more than just technology. We can’t sit by and watch everything burn around us while we wait for new drugs to come down the pipe…. because they aren’t coming. (Project Syndicate)

4. I want to deny vaccine deniers. Generally speaking, I don’t like people who are willing to sacrifice kids for politics. Vaccine deniers stick together and increase risks for everyone. (WP) and this one, which puts it all into a nice picture for you. (WP)

5. Diseases without borders: ignoring the problem of piss poor health care in developing countries won’t help us from Jim Kim of the World Bank. (Project Syndicate)

Does the environment cause poverty?

SESKwaleAfrican countries are blessed with ample cropland and resources, but suffer from crippling and unforgivable levels of poverty, have some of the shortest lifespans on the planet and the highest rates of infant mortality in the world. Meanwhile, Japan, Korea, Sweden, Switzerland and Singapore are wholly the opposite, yet mostly lacking in everything that Africa has. Clearly, the picture is more complicated than merely having access to a natural resources.

However, within countries, the picture might be different. African countries are complex and diverse places. Poverty is often confined to the most unproductive regions, areas with poor soils, poor rainfalls or dangerous terrains.

I was just working with some socio-economic data from one of our field sites, and noticed some interesting patterns (note the map up top). In Kwale, a small area along the Coast, socio-economic levels vary widely, but neighbors tend to be like neighbors and patterns of socio-economic clustering emerge.

Note that the poorest of the poor are concentrated to an area in the middle, which I know to be extremely dry, difficult to get to, difficult to farm and generally tough to live in.

I tried to see if socio-economic status (as measured through a composite material wealth index a la Filmer and Pritchett but using multiple correspondence analysis rather than PCA) was related to any environmental variables that I might have data for.

I fit a generalized additive model using the continuous measure of of wealth from the MCA as an outcome. Knowing that very few things in nature or human societies are linear, I also applied smoothing to the predictors to relax these assumptions. The results can be seen in the plot at the bottom.

A few interesting things came out. While it is hard to tell much about the poorest of the poor, we can tell something about the most wealthy. The richest in this poor area, tend to live in areas with the richest vegetation (possibly representing water), a high altitude (low temperature), high relief (no standing water) and in locations distant from a wildlife reserve (far from annoying and dangerous wildlife).

I’m not sure the wildlife reserve is meaningful (unless the reserve was an area undesirable for human habitation to begin with), but the others might be and represent a trend seen in other Sub-Saharan contexts. Areas without malarious swamps and ample farm land tend to do the best. Central Province, one of the most developed areas of Kenya, would be an example.

But the question has to be, does a harsh environment doom people to poverty, or do people self shuffle into and compete for access to more favorable areas? Is environmentally determined poverty (or wealth) an accident of birth, or the result of competitive selection?

Alright, back to work. Oh wait, this is my work. Well….

Results of GAM model of SES in Kwale. Y axis is the continuous measure of socio-economic status.

Results of GAM model of SES in Kwale. Y axis is the continuous measure of socio-economic status.

Today is Jonas Salk’s 100th birthday

100 years ago today, Jonas Salk was born. As the creator of the inactivated polio vaccine, he not only changed the course of human history, he also ushered changed the field of public health forever. We can count the polio vaccines and the elimination of smallpox as probably the two great success of public health.

In its mildest form, polio causes a mild bout of diarrhea. In its worst form, the virus migrates to the spine, impedes development and causes debilitating long term paralysis. My grandfather was struck with the disease and had one of his legs stunted and weakened (though he managed to serve in WWII anyway as a Marine). A carpenter who worked for me a while back died due to long term respiratory complications from a childhood polio infection.

Polio is mostly foreign to anyone born in my generation. We were nearly all vaccinated, and the high levels of vaccination have destroyed opportunities for the virus to persist in the environment, protecting everyone, even those who don’t get the vaccine.

Unfortunately, though Salk’s achievements were great, medical care and attention to polio was hardly equitable and tainted by the racism of the time.

During the 1930s the systematic neglect of Black polio victims had become publicly visible and politically embarrassing. Most conspicuously, the polio rehabilitation center in Warm Springs, Ga, which Roosevelt, himself a polio survivor, had founded, accepted only White patients. This policy, reflecting the ubiquitous norm of race-segregated health facilities, was sustained by a persuasive scientific argument about polio itself. Blacks, medical experts insisted, were not susceptible to this disease, and therefore research and treatment efforts that focused on Black patients were neither medically necessary nor fiscally justified.[1]

It is likely true that African Americans experienced a lower burden of disease than white children. We now know that polio’s worst effect arise from the lack of acquired immunity to the disease. Repeated infections from infancy, most importantly during the first six months, when babies still have maternal antibodies to fight for them. Improvements to sanitation delayed exposure to the virus, so that children were not immune and thus more susceptible to the disease’s worst effects.

In short, polio is a disease of development, not underdevelopment. The horrible racism of the pre-civil rights medical system can’t be denied, but the observed disparities in disease incidence might have not been imagined given the disparities in sanitation and access to clean water.

Presently, we are fighting a battle to insure that all kids in Sub-Saharan Africa are vaccinated. However, there still exist pockets where the medical system so dysfunctional and the politics so chaotic, that vaccination rates are low and disease continues to flourish. In places like Afghanistan and Northern Nigeria, the hope of polio elimination is almost non-existent

 

1.    Rogers N: Race and the Politics of Polio: Warm Springs, Tuskegee, and the March of Dimes. American Journal of Public Health 2007, 97(5):784.

 

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.

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