Malaria transmission to decline in Burundi because of global warming

Malaria transmission will not increase because of global warming in the African nation of Burundi according to a statistical analysis by researchers in Austria and Burundi. Writing in the International Journal of Global Warming, the team explains that rising temperatures will lead to lower humidity and rainfall which will shorten the lifespan of mosquitoes carrying malaria.

Statistician and epidemiologist Hermenegilde Nkurunziza of the University of Burundi and statistician Juergen Pilz of the University of Klagenfurt, Austria, analysed data on monthly  rainfall,  temperature  and  humidity  data  as  well  as  monthly malaria  morbidity  data  from Burundi for 1996-2007. Data   on   monthly  malaria  morbidity  for  each  province  of  Burundi  were  collected  from  Epidemiology  and  Statistics  (EPISTAT),  a  department  of  the  Burundi  Ministry  of  Health  collecting  and   storing   data   on   epidemiology   all   over   the   country. The researchers used Bayesian Generalised  Additive  Model  (GAM) to process the data and found that although malaria transmission is positively associated with minimum temperature and maximum humidity,  increasing  temperature  in  Burundi  will  not  result  in  increasing malaria transmission.

Malaria  is  the  main  public  health  problem  in  Burundi with transmission  of  the disease  being strongly  influenced  by  several climatic  factors. There are around 2 million clinical cases and more than 15,000 deaths each year. It is responsible for half of hospital  deaths  among children  under  5  years  and  40%  of  consultations  in  health  centres.

Temperature is a significant factor, with higher temperatures reducing the incubation period for the disease. Rainfall influences mosquito populations by increasing the vegetation density and the capacity of larva production and maturation. Higher humidity extends adult mosquito life span to lengths commensurate with increased infection rates.