Climate variability and dengue incidence

Nov 16, 2009

Research published this week in PLoS Medicine demonstrates associations between local rainfall and temperature and cases of dengue fever, which affects an estimated fifty million people per year worldwide. But the study finds little evidence that the El Niño-Southern Oscillation - the climate cycle that occurs every three to four years as a result of the warming of the oceans in the eastern Pacific - has a significant impact on the incidence of dengue in Mexico, Puerto Rico or Thailand.

Large outbreaks of dengue, a vector-borne viral disease spread by the Aedes aegypti mosquito, occur every few years in many tropical countries. Michael Johansson, of the in Puerto Rico, used a technique called "wavelet analysis" to probe relationships between the local climate, El Niño, and incidence of dengue in Mexico, Puerto Rico and Thailand — three countries where dengue is endemic. They were able to separate and compare seasonal and multiyear components of each. In all three countries temperature, , and dengue incidence varied strongly on an annual scale, showing association in the wavelet analysis.

On the multiyear scale however, the researchers found no association between El Niño and dengue incidence in Mexico, a statistically insignificant association in Thailand, and an association in Puerto Rico only significant for part of the study period. The authors warn that the Puerto Rico outcomes should be viewed with caution.

The authors acknowledge that El Niño could still play a role undetected by this research. But as Pejman Rohani of the University of Michigan - uninvolved in the research - states in a related Perspective, the absence of a predictable link between El Niño and dengue transmission "is an important piece of information for the development of early warning systems".

More information: Johansson MA, Cummings DAT, Glass GE (2009) Multiyear Climate Variability and Dengue— El Niño Southern Oscillation, Weather, and Dengue Incidence in Puerto Rico, Mexico, and Thailand: A Longitudinal Data Analysis. PLoS Med 6(11): e1000168. doi:10.1371/journal.pmed.1000168

Related PLoS Medicine Perspective: Rohani P (2009) The Link between doi:10.1371/journal.pmed.1000185thern Oscillation. PLoS Med 6(11): e1000185. doi:10.1371/journal.pmed.1000185

Source: Public Library of Science (news : web)

Explore further: Sierra Leone faces criticism over Ebola shutdown

add to favorites email to friend print save as pdf

Related Stories

Local climate influences dengue transmission

Feb 17, 2009

Researchers from the US Centers for Disease Control and Prevention (CDC) and the Johns Hopkins Bloomberg School of Public Health have found that dengue transmission in Puerto Rico is dependent upon local climate and short-term ...

Study: Dengue fever is underreported

Oct 16, 2007

The American Society of Tropical Medicine and Hygiene is concerned about the U.S. blood supply due to underreporting of dengue fever.

Forecasters say El Nino may be developing

Jun 08, 2009

(AP) -- A new El Nino could be approaching. Sea-surface temperatures have been warming in the tropical Pacific Ocean, suggesting the potential for the development of the El Nino climate phenomenon this summer, according ...

Recommended for you

Sierra Leone faces criticism over Ebola shutdown

8 hours ago

Sierra Leone began the second day of a 72-hour nationwide shutdown aimed at containing the spread of the deadly Ebola virus on Saturday amid criticism that the action was a poorly planned publicity stunt.

Presence of peers ups health workers' hand hygiene

23 hours ago

(HealthDay)—The presence of other health care workers improves hand hygiene adherence, according to a study published in the October issue of Infection Control and Hospital Epidemiology.

Sierra Leone streets deserted as shutdown begins

Sep 19, 2014

Sierra Leone's normally chaotic capital resembled a ghost town on Friday as residents were confined to their homes for the start of a three-day lockdown aimed at halting the deadly Ebola epidemic.

Sierra Leone launches controversial Ebola shutdown

Sep 19, 2014

Sierra Leone on Friday launched a controversial three-day shutdown to contain the deadly spread of the Ebola virus, as the UN Security Council declared the deadly outbreak a threat to world peace.

User comments : 0