Two days ago a report appeared in various places announcing the results of a new paper tying malaria to “global warming.” I’d like to find the paper but I haven’t the time. Does anybody out there have it?
The news report (click here) is as follows. No mention of the journal or paper except that its results are “conclusive.”
Study finds climate change, malaria spread link
Scientists have produced more evidence of a strong link between climate change and the spread of malaria.
A study in the highland parts of Kenya has identified a significant increase in cases of malaria over a 30-year period, apparently caused by a rise in temperature of just half-a-degree Celsius.
Professor Mercedes Pascual from the University of Michigan says the results are conclusive.
“We have asked whether climate change could explain the pattern of increased risk in the size and frequency of epidemics. The answer is yes it can,” she said.
“Warmer temperatures can explain an eight-fold increase of cases during epidemic months according to our models.”
The scientists say the findings show that highland areas of eastern and central Africa are likely to see a rapid rise in the number of malaria cases as temperatures rise and mosquitos become more abundant.
The website of one of the authors is here. No words about the paper there.
Pascual collaborated on the research with Jorge Ahumada of the University of Hawaii, U-M graduate student Luis Chaves, Xavier Rodo of the University of Barcelona and Menno Bouma of the London School of Hygiene and Tropical Medicine. The research originated at a working group on Global Change and Infectious Disease at the National Center for Ecological Analysis and Synthesis (Santa Barbara, Calif.), a center supported by the National Science Foundation and the University of Santa Barbara, and additional support was provided by the National Institutes of Health, the National Oceanic & Atmospheric Administration and the James S. McDonnell Foundation in Global and Complex Systems
This could be what you are looking for:
Malaria resurgence in the East African highlands: Temperature trends revisited
This is yet another rehash of the same malarky I first heard a good 15 years ago.
At that time, it was “malaria will reach the northern US due to global warming” being flogged to nurses. Anyone with a few spare minutes could have found a map showing that malaria rarely strayed north of the Mexican border. Another map set in the 1800s showed malaria reaching into southern Canada – a cold place then and now.
All nothing to do with AGW or any kind of warming. As swamps were drained, mud tracks paved, and eventually the arrival of air conditioning on a large scale, the mosquitos and malaria retreated south.
Whenever I see yet another AGW = Malaria story, I am torn between laughing and shaking my fist at the abject stupidity of such claims.
Might be the one; looks plausible. But news report made it sound like it was a new one. Perhaps based on that older one?
At the risk of drifting off topic, I’d like to confirm what Scumop noted above about malaria reaching into Canada in the 1800s. In fact, according to historians malaria was it was present in Ontario as early as the 1700s. This overview of the history of the construction of the Rideau Canal (in 1827-31) describes the conditions:
The Rideau Canal northern limit reaches at Ottawa, at approximately latitude 45N.
Malaria doesn’t care about warming – “man made” or otherwise.
The new and brilliant biography of Samuel Champlain by David Hackett Fischer, I believe, suggests that Samuel Champlain contracted malaria around 1620. Whether other Europeans brought it or he contracted it elsewhere I do not know. Certainly mosquitoes were present in huge numbers.
To your comments on a lack of logic , I have added weak arithmentic and a lack of geographical knowledge at the Wonk Room. Namely,
You say: “The climate of NJ has already shifted the equivalent of about 30 miles south since 1960 (see also this Audubon report on shifting bird migration and this NWF map on shifting plant hardiness zones).
Essentially, New Jerseyâ€™s climate today is what Delawareâ€™s was 40 years ago (and Delawareâ€™s climate is what southern Virginiaâ€™s used to be, etc.), which is disrupting the established ecosystem.”
The first rule in consulting is size the problem. For that you typically need a few basic facts, some simple arithmetic and some logic. Your math and/or your geography and/or logic is screwy – which is pretty surprising for a MIT grad – but then perhaps it says a lot.
By my calculation the climate is moving north (not south as you suggest) by about 6 miles per decade. Which means that Camden, NJ (just outside of Philadelphia in Southern New Jersey) now has the same climate that Wilmington Delaware (actually Northern Delaware) had in 1960! Since I think Wilmington has a pretty pleasant climate compared to Boston I figured out that if the rate of climate improvement stays pretty much the same, Boston will be like Wilmington is today in say between roughly 300 and 500 years depending how you measure the distance between Boston and Wilmington.
Brad, please feel free to point out any errors in my geography, arithmetic, or logic in the above. If none, then think about why many of the folks who have come here think you guys are loopy.
Gail, honey, do you see why many are not quite as upset as you seem to be.
P.P.S. Gail, how is that Geothermal business idea coming?
I hadn’t even noticed it was an old article and I couldn’t find a recent one, so I sent professor Pascual an email and asked her.
Paul Reiter is one of the worldâ€™s leading experts on vector illnesses. He tells an interesting story of how he discovered the malaria mosquito in residual water trapped in old tyres that are shipped around the world in the second hand (recycling) trade. They travel on jumbos and 747â€™s first class of course. (not the tyres, the mosquitoes!)
London was malarious until improvements were made in sanitation. Malaria has been recorded at high altitudes and high latitudes in the past. Itâ€™s not about hot or cold, they need the right conditions for breeding, and shelter is easy to find, where there are humans, there is shelter and usually a supply of stagnant water.
I know all the regulars know all that but there could be some wonkers lurking still who need an education.
Paul Reiter (hope that’s how he spells his name) also left the IPCC in disgust and threatened legal action in order that they took his name from the list of scientists. He took his complaintabout the IPCC to our parliament. I have the transcript somewhere in my collection but can’t be asked to look for it. It’s easier to find it on a google search.
I suspect the news bit is based on something from the AAAS meeting –
My 3:38 post is on the wrong thread. It should be on the Joker thread obviously. I guess I was having too much fun to notice!
Perhaps it came from here:
February 16, 2009 in Scientific American Online, Environment
Rise in Malaria Rates, Drug Resistance Tied to Climate
At AAAS, a researcher describes how treating more people for the mosquito-borne parasite could lead to more resistance to drugs
By Andrew McGlashen
“The literature has this controversy of ‘Is it climate or is it drug resistance?’ and drug resistance is taken as evidence that we donâ€™t need to invoke climate change,” she added.”
“No research has shown this synergy, but Pascual said it makes theoretical sense.”
“No research” but, it makes “theoretical sense”…???
30 Years Ago – Back when the successful movement to ban DDT started up. I think Rachel Carson can best be blamed for this new crisis
There are a variety of haemosporidian parasites (Leucocytozoon, Plasmodium, and Haemoproteus spp. for instance) and viruses (Flaviviridae, for instance) that affect birds and people and that are spread to hosts via insect vectors including mosquitoes (Culicidae), biting midges (Ceratopogonidae), hippoboscid flies (Hippoboscidae), and black flies (Simuliidae). The vector pathways are complex. The postulated 1 degree C global temperature rise over the last century is probably not a factor, whereas changes in animal and human populations and their demographics, land use, and pesticide use and disuse (such as DDT) probably are.
By the way, from Wiki:
“There are approximately 3,500 species of mosquitoes grouped into 41 genera. Human malaria is transmitted only by females of the genus Anopheles. Of the approximately 430 Anopheles species, while over 100 are known to be able to transmit malaria to humans only 30-40 commonly do so in nature. Since breeding and biting habit differ considerably between species, species identification is important for control programmes.”
How did they control for the different conditions of the humans being exposed to the malaria mosquito? Controlling research like this is extraordinarily difficult–I’m surprised the professor claimed it was conclusive.
It seems the one major difference in Kenya over the last decade+ is that they’ve stopped treating with DDT. It might be very difficult to control for the change in treatment regime, especially since DDT is somewhat persistent in the environment, and might lead to a gradual growth in mosquito population when removed.
Note that the KÃ¶ppen Climate Boundary in the US was furthest south in the 1930s and furthest north in the 1970s.
In Elizabethan times malaria was called ague.
One of the worst malaria outbreaks was in the polar circle region of northern Russia early in the last century.
Matt/Briggs/William [delete whichever is inapplicable] Can’t find anything recent on the effect of climate change on schistosomiasis transmission. I’ll ask my doctor when I see her next. UTAS conducts research in this area.
I think she’s some kind of modeller.
Becoming an HHMI investigator will enable Pascual, whose expertise is in epidemiology and computational biology, to expand her work building models of the dynamics of cholera and malaria in different locations in South Asia and Africa.
Perhaps the paper has yet to be published:
“His predictions were supported by new, unpublished data…”
from second to last paragraph in this article:
And, in answer to the modeling reference is this quote from the last paragraph:
“The scientist behind the research, Mercedes Pascual, of the University of Michigan, Ann Arbor in the United States, told the meeting: “The predictions we make [using current models] are below the observed number of cases.” “
The link given by Bruce Foutch above begins: “Climate change could have unexpected effects on the incidence of malaria â€” even reducing it in unforeseen places, says an insect expert”, though that’s another speaker. Sounds like “conclusive” it ain’t.
Or it could it be that being a “theoretical” ecologist might have some bearing on her findings? Maybe it’s merely “theoretically” conclusive? The more I look into it the more it looks like warmed over screed from two or three years ago.
It certainly sounds like Malaria has been a big problem in the past. If so, what was done to solve the problem? If it was insect control, and if insect control globally has been hampered by the removal of one of the most effective insecticides used, namely DDT, and if the removal of DDT coincides with the turning point in Malaria cases, then it would seem to me, JA, a non-scientist that the loss of DDT is more at fault than any other suspect.
But that’s just me, JA, a non-scientist. Still I would advise world leaders to reintroduce DDT as an anti-Malarial treatment.
M.Pasqual et al. 2008, Shifting patterns: malaria dynamics and rainfall
variability in an African highland
Hereâ€™s the Paul Reiter link for anyone who hasnâ€™t yet read what he has to say on the subject, one of my yesterday comments.
I was under the impression that DDT was back in use again and is no longer banned.
Mr PG yes, â€œsick of the ague.â€ But this also became over used like â€˜the fluâ€™ nowadays.
In some fields you can’t get research grants these days without the magic words ‘climate change’. So if you want to study volcanoes, meteorites, sticklebacks, pornography or breakfast time television you just find a link to CC, no matter how tenuous, and the brown envelopes start to arrive.
1: Malar J. 2008 Jun 2;7:100. Links
Malaria transmission pattern resilience to climatic variability is mediated by insecticide-treated nets.Chaves LF, Kaneko A, Taleo G, Pascual M, Wilson ML.
Department of Ecology and Evolutionary Biology, The University of Michigan, Ann Arbor, MI 48109-1048, USA. firstname.lastname@example.org
BACKGROUND: Malaria is an important public-health problem in the archipelago of Vanuatu and climate has been hypothesized as important influence on transmission risk. Beginning in 1988, a major intervention using insecticide-treated bed nets (ITNs) was implemented in the country in an attempt to reduce Plasmodium transmission. To date, no study has addressed the impact of ITN intervention in Vanuatu, how it may have modified the burden of disease, and whether there were any changes in malaria incidence that might be related to climatic drivers. METHODS AND FINDINGS: Monthly time series (January 1983 through December 1999) of confirmed Plasmodium falciparum and Plasmodium vivax infections in the archipelago were analysed. During this 17 year period, malaria dynamics underwent a major regime shift around May 1991, following the introduction of bed nets as a control strategy in the country. By February of 1994 disease incidence from both parasites was reduced by at least 50%, when at most 20% of the population at risk was covered by ITNs. Seasonal cycles, as expected, were strongly correlated with temperature patterns, while inter-annual cycles were associated with changes in precipitation. Following the bed net intervention, the influence of environmental drivers of malaria dynamics was reduced by 30-80% for climatic forces, and 33-54% for other factors. A time lag of about five months was observed for the qualitative change (“regime shift”) between the two parasites, the change occurring first for P. falciparum. The latter might be explained by interspecific interactions between the two parasites within the human hosts and their distinct biology, since P. vivax can relapse after a primary infection. CONCLUSION: The Vanuatu ITN programme represents an excellent example of implementing an infectious disease control programme. The distribution was undertaken to cover a large, local proportion (approximately 80%) of people in villages where malaria was present. The successful coverage was possible because of the strategy for distribution of ITNs by prioritizing the free distribution to groups with restricted means for their acquisition, making the access to this resource equitable across the population. These results emphasize the need to implement infectious disease control programmes focusing on the most vulnerable populations.
PMID: 18518983 [PubMed – indexed for MEDLINE]
John, that’s excellent. Thanks very much.
I’ll still try and get the paper, but reading the abstract shows no “smoking gun.” Mosquito life cycles correlate well with temperature and precipitation? Who knew?
I now have the paper. Thanks to you all. I’ll be reviewing it on the blog soon.