One more benefit of warming?

Guest post by Indur M. Goklany

Buried in a story on the effects of climatic variables on rotavirus, which apparently kills half a million children annually, is the following quote:

The incidence of rotavirus throughout Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka was higher during the coldest, driest months of the year — from December to March–the study indicated. Increases in temperature and precipitation in other parts of the year resulted in lower levels of the virus. Patterns were consistent across the geographical regions, though the fluctuations varied in intensity.

According to the CDC:

Rotavirus is the most common cause of severe diarrhea among children. Prior the introduction of rotavirus vaccines in the United Sates in 2006, rotavirus resulted in the hospitalization of approximately 55,000 U.S. children each year. Globally, rotavirus is estimated to cause 527,000 deaths in children annually. The incubation period for rotavirus disease is approximately 2 days. The disease is characterized by vomiting and watery diarrhea for 3 to 8 days, and fever and abdominal pain occur frequently. Immunity after infection is incomplete, but repeat infections tend to be less severe than the original infection.

For some context, total US deaths from all causes is 2.4 million annually. So half a million deaths is huge.

Had the findings been that warmer and wetter increased rotavirus, I wonder if the headline would have been as restrained and non-committal as it is, and whether the results would have been buried in the 8th para.

Story, from Science Daily, follows. Highlighting is mine.

 

Weather Patterns Can Be Used to Forecast Rotavirus Outbreaks

ScienceDaily (May 31, 2012) — Monitoring weather factors like temperature, rain, and snowfall is one way to predict the timing and intensity of rotavirus, a disease that causes extreme diarrhea, dehydration and thousands of death annually, particularly among children.

In a paper published May 31 in the journal PLoS One, a research team led by Elena Naumova, Ph.D., professor of civil and environmental engineering at Tufts School of Engineering, correlated temperature and precipitation with rotavirus outbreaks in one of the hardest-hit regions of the world, South Asia.

In 2004, rotavirus resulted in 527,000 deaths worldwide in children younger than five years, the study noted. The majority of deaths are clustered in poor areas of developing countries in Africa and Asia. Being able to predict infection increases opportunities for health professionals to take effective preventive measures such as vaccination that could substantially reduce deaths.

Naumova’s research focuses on developing methodology for analysis of large databases to enhance disease surveillance. In this study the team examined seasonal differences in the environment by creating mathematical models based on factors such as temperature, humidity and precipitation in the region over 22 years.

“We found that rotavirus is sensitive to seasonal patterns that are defined as a combined effect of temperature and precipitation,” said Naumova, who is senior author of the study. This work builds on Naumova’s previous research developing mathematical models to predict the timing, severity, and impact of diseases. “Our goal is to develop an integrated model which will allow monitoring the virus and also forecasting outbreaks.”

Naumova and the research team analyzed monthly rates of rotavirus from 39 published epidemiological studies that were conducted on outbreaks between 1988 and 2010.

In this new model, the researchers considered meteorological characteristics based on data from the National Climatic Data Center and the Global Historical Climatology Network to classify four geographic regions in South Asia — moist tropical climates; arid and semiarid; humid, mid-latitude areas, and cold temperature areas.

The incidence of rotavirus throughout Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka was higher during the coldest, driest months of the year — from December to March–the study indicated. Increases in temperature and precipitation in other parts of the year resulted in lower levels of the virus. Patterns were consistent across the geographical regions, though the fluctuations varied in intensity.

Additionally, the researchers found an association between rotavirus and vegetation density. Using remote sensing data derived from satellite images produced by moderate resolution imaging spectroradiometer (MODIS), a sensor on NASA’s Terra satellite, the researchers were able to monitor and measure the amount of fresh vegetation across the region. A second source of remote sensing data was provided by the Global Inventory Monitoring and Mapping Studies (GIMMS).

The images were processed using mathematical techniques for turning satellite data into vegetation growth measurements. Researchers were able to measure changes in vegetation from 2000 to 2007. An analysis of data associated decreases of vegetation with an increase in the virus.

Naumova is the director of the Tufts Initiative for the Forecasting and Modeling of Infectious Diseases (InForMID), which works to improve biomedical research by developing computational tools in order to assist life science researchers, public health professionals, and policy makers.

Collaborators on the study included Jyotsna Jagai of the USA Environmental Protection Agency, Rajiv Sarkar, Deepthi Kattula, and Gagandeep Kang of the Christian Medical College in Vellore India; Denise Castronovo of Mapping Sustainability LLC; Jesse McEntee of Cardiff University in Cardiff Wales; and Honorine Ward of Tufts University School of Medicine.

This study was funded by the National Institute of Environmental Health Sciences, the National Institutes of Health, the Ruth L. Kirchstein NIH National Research Trainee Fellowship and the FIC Global Infectious Disease Research Training grant. The study received additional support from the Indo-U.S. Collaboration on Environmental and Occupational Health.

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26 thoughts on “One more benefit of warming?

  1. Influenza has a strong seasonality, and is more common in the cold months. But the severity of a particular Influenza outbreak has little to do with the actual winter temperatures-and thus cold weather is likely not the direct cause. One wonders if a similar thing could go on in a study such as this, and whether it would be at all appropriate to assume that relationships between present weather and infectious diseases that arise from common seasonality can really be extrapolated to the case of changed weather under hypothetical AGW. I find the claim that AGW would reduce the prevalence of a viral infection no more credible than the claim it would increase it, which is to say not at all, without very compelling evidence. I would like to see it for myself.

    After all, a virus exists in it’s own microscopic environment whose ambient “weather” conditions need not bare any resemblance to the much larger scale average estimated at a nearby weather station.

  2. “Globally, rotavirus is estimated to cause 527,000 deaths in children annually.”
    “For some context, total US deaths from all causes is 2.4 million annually. So half a million deaths is huge.”
    The final statement does not seem to follow from the previous two.

  3. I live in Mexico, and both my daughters got rotavirus around the age of crawling / starting to walk, in the season (Mar – Jun) when it’s warm, but at the end of a long period (6 months or more) of no rain (the rainy season starts June – July). According to pediatricians, they pick it up from the ground. It would seem from this experience, anecdotal only, that precipitation is more important than temperature. It’s a severe disease: my younger daughter was hospitalised for three days for dehydration, and in poverty it can easily kill.

  4. @Andrew.

    Valid point. But there are human behavioral changes that occur that can directly affect the spread of a virus… and these changes are directly related to the ambient weather.

    When it’s cold, people tend to seek heat.

  5. These results look pretty clear cut, although there is no link to the paper itself.

    It doesn’t mean temperature has a direct effect. It may be an indirect effect, such as people in closer proximity during cold months or that they wash less. It’s well established viruses live longer in cool dry weather. Viruses also live longer in winter due to reduced sunlight, so there may be an indirect effect from precipitation; more clouds -> less sunlight.

  6. ‘benefits of warming’….
    Off-topic but related to warming: one person I communicate with, tells me the corn in central Virginia is already waist-high. They planted almost a month early due to the mild winter!

    I’m hoping there are bumper crops across the country.

  7. Having encountered rotavirus (in young calves – the human animal is not that much different), all I see/read here is yet more gumpff attempting to blame everything on Global Warming and hence pass the buck (via taxation and general feelings of guilt) to anyone who burns fossils.
    From the CDC link:-
    The primary mode of transmission is via fecal-oral route. Because the virus is stable in the environment, transmission can occur through ingestion of contaminated water or food
    For persons with healthy immune systems, rotavirus gastroenteritis is a self-limited illness, lasting for only a few days. Treatment is nonspecific and consists of oral rehydration therapy to prevent dehydration. About 1 out of 70 children with rotavirus gastroenteritis will require hospitalization for intravenous fluids.

    In other words, rotavirus is similar to any other ‘condition’ caused by overcrowding and unsanitary living conditions while at the same time is relatively benign in an otherwise healthy population. Only 1 in 70 will be hospitalised and treatment is very simple with salt & sugar solution or even flat Coca-Cola.
    Sorry global climate scientists, no cherries/funds/grants to pick here, clean water is all that’s needed.

  8. Andrew, Philip Bradley

    I agree. Note the question mark in the title.

    Also, I suspect that more important than climatic factors are a whole slew of socioeconomic factors, including the general health of the population (which correlates quite well with socioeconomic factors, particularly wealth). I have a number of papers, etc., on the relationship between health and wealth at http://goklany.org.

  9. Peter Hannan says:@ June 6, 2012 at 12:00 am

    Also read up on giardia and lifecycle. While not fatal, can be very debilitating.
    I was fortunate to be taught by old-school medicos (male).

    Shigella, campylobacter, salmonella – 6-8-10 watery bowel movements per day: colour (green, ‘red’, yellow) & smell taught us which of the above and appropriate treatment. And treat quickly with kids and elderly. One can diagnose by the skin turgor and general appearance.
    Rotovirus – less of colour and smell but treat quickly with kids/elderly as above
    Giardia – 2-3 bowel movements/day + smell and colour. May be long term (chronic). Check water infrastructure and dust blow-off in the environment.
    Cholera- I have no experience of.

    We had few deaths, previously had to use intra-peritoneal infusion to save lives.
    I can not find a graphic for any of this, even on Hesparian (Where There is No Doctor)!

    http://hesperian.org/digital-commons/

  10. Indur M. Goklany

    Thank you for posting such an important topic. And the research of this in regard to child mortality and family life.

    I had the wonderful opportunity to work with sorcerers (medicine-men), who in their own small environments were able to utilise localised observations of phenomena and their power substantiated in a small group, as fear & terror.

    And then when faced with men of western science, with a far more geographic and replicable nature, these men had the courage to work with these other men to deliver vast benefits to a far greater number and spread of their people. Truly remarkable men they were all.

  11. Weather Patterns Can Be Used to Forecast Rotavirus Outbreaks
    and so I guess Rotavirus outbreaks can be used as a proxy for weather patterns.

    The less Rotavirus infection the higher the temperature. I can imagine a hockey stick forming as sanitation improvements and modern medicines reduce the incidence of rotavirus infections and so indicate rising temperatures ;>)

  12. GeoLurking says: “But there are human behavioral changes that occur that can directly affect the spread of a virus… and these changes are directly related to the ambient weather.”

    Mostly, they relate to the large changes associated with the seasonal cycle. The seasonal anomalies of temperature have no apparent impact on influenza, for instance. My question is: if the effect is due to the large seasonality’s impact on human behavior (is it? someone who has read the study please tell me some details) then should we expect climate change to actually change the seasonality so much that it changes human behavioral reaction to it?

  13. If warming is bad, how is it we are feeding 7 billion today, when 50 years ago during the global cooling scare we were having trouble feeding 3 billion?

  14. Otter says:
    June 6, 2012 at 1:22 am

    “Im hoping there are bumper crops across the country.”

    No! Bumper crops will lead to more food which will lead to obesity. And, clearly, obesity is entirely due to global warming! We can’t have that! We need less food, more anxiety, more panic – because that’s what we at climate science inc. are all about – making loads of money (for funding our extravagant climate science salaries and benefits) by scaring the public.

    /sarc

  15. Ever since I read in Dead Men Do Tell Tales, by forensic anthropologist, that the bacteria that causes leprosy likes it cool and that is why it attacks the extremities and the nose, I thought that our increasing inflammation load that seems is connected to heart disease, diabetes, lupus, lymes, chronic fatigue, etc., is one of the major reasons we do not now have a sourge of leprosy. Our internal inflammation keeps the body warmer than the leporsy bacteria likes.
    What happens when we get a new ice age?

  16. For some context, total US deaths from all causes is 2.4 million annually.

    CDC Source says for 2009 there were 2,437,163 deaths.

    From the US Census Bureau the 2000 US population was 281,421,906, 2010 was 308,745,538, by linear interpolation 2009 was 306,013,175.

    So by straight linear math in 2009 we had 125.6 years of death until the current population is removed. Or to put it another way, at that removal rate everyone alive in the US in 2009 had an average 62.8 more years to live.

    However the CDC also says the 2009 life expectancy was 78.5 years. So doesn’t that put the average age of a person in the US in 2009 at 15.7 years old? Yet the national median age in 2009 was 36.8 years old (source), more than twice as much.

    How do they come up with these numbers anyway?

  17. I don’t get it.

    For some context, total US deaths from all causes is 2.4 million annually.

    310 million people in the U.S., life expectancy 78 or so. I would have thought we’d have something like 310 million / 78, or about 4 million deaths per year.

    Can anyone explain what I’m doing wrong?

    [REPLY: Why would you divide the population by 78? That is average life expectancy, and people over 75 represent less than 5% of the population. -REP]

  18. kadaka (KD Knoebel) says: June 6, 2012 at 9:04 am

    First, the median age is the number where 50% of the population is older and 50% younger. Linear extrapolations don’t work in demography. Age groups are not represented equally in a population. In the United States, as in most other developed countries, the birth rate has been declining as has the infant mortality rate; at the same time life expectancy has increased. You need to think in terms of a population pyramid, which in the developed world is not really a pyramid at all, but rather currently looks like a boa constrictor that has swalled a basket-ball.

    http://www.usc.edu/dept/gero/AgeWorks/core_courses/gero500_core/demographics_lect/index_a.htm

  19. As much as this is funny and ironic that you find that some diseases/viruses are not as prevelant in warmer weather, the truth is that like any disease, the climate plays very little role for humans in this. Disease vector control is always going to beat anything else in disease prevention and saving lives. IE: controlling the mosquito for malaria….etc

    And to add to this, as nerd is saying, Vitamen D defiency is a good cause of lots of people getting sick in winter months. It goes without saying that if you boost your Vit. D intake during the winter you can probably control the cold and/or flu much better then any other method. A change of 0.8 C over 100 years is going to have a much smaller effect then the disease vector controls as in quarentine when sick, Vitamen supplements during winter months, and of course the old flu shot.

    It just goes without saying that medicine is heading from pure science and facts into the tabboo land of shock journalism. That does not mean that warmer temperatures (or colder temperatures as in this case) have NO effect on the diseases, it just means that these have a very small impact compared to other things we can do such as intelligent adaptation like I was saying. When scientists miss simple big picture items like this, they make huge mistakes and more often then not simply make themselves appear foolish. Perhaps they are not foolish or stupid, but by making these simple mistakes they make themselves out to be like that.

    And the terrible thing is that by wasting resources on finding out what a small effect warming will result in, we all end up losing since real science is tossed aside and real possible life-saving discoveries are not made as the scientists waste everyone’s time and come up with fluff like this. Just more wasting of resources….

  20. The diarrhea diseases will continue to exact a terrible toll until sanitation reaches much more of the partly- or un-developed regions of the world. A recent initiative to install sanitary toilets in certain villages in India was received very well by the population, after a long and intense campaign of education about the spread of diseases from feces; prior to the installation, the most common method of waste disposal was open defecation. There may be some distant or obscure cause/effect relationship with ambient temperature, but my bet is on sanitation or its lack as being the most predictive factor. The weather angle is interesting, but to me seems less than convincing as a cause.

  21. As katesisco sez, ‘ware the coming cooling. The approaching Minimum is going to cut a large swathe through a lot of places that have been spending time, effort, and resources on trying to parasitize the AGW Boom/Scam.

  22. Reblogged this on gottadobetterthanthis and commented:
    While the key must be improvements in sanitation, the obvious “good” in this article is vaccines. Please support vaccination programs in all ways. Avail yourself and your children to vaccines, and support efforts to vaccinate all over the world.

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