Environment &Epidemiology Bill Brieger | 30 Nov 2008 07:44 am
Kenya’s changing malaria profile
Kenya is facing at least two major and seemingly opposing changes in its malaria epidemiological profile. SciDev.net reports on an article from The Lancet that confirms, “An analysis of data collected over 18 years from malaria-infected children at Kilifi District Hospital, on Kenya’s Indian Ocean coast, found that paediatric admissions for malaria had fallen by 75 per cent over a period of just five years.”
At the same time, “In recent years malaria has also appeared in the highland areas where it was previously unheard of,” according to Inter Press Service (Johannesburg). Keeping pace with these changes is essential if the national malaria control services and its malaria donor partners are to provide appropriate interventions for each part of the country.
In the highlands where people are less used to malaria, Sumba and colleagues found that. “A significant proportion of this highland population chooses local shops for initial malaria treatment and receives inappropriate medication at these local shops, resulting in delay of effective treatment.”
Because highland residents, for example those in Kibera, Nairobi, travel back to their home villages in malaria endemic areas, they bring the parasites back. With the potential of global warming making the highlands more favorable to malaria transmitting mosquitoes, the highlands will face increasing risk, according to an IRIN news release. Furthermore, “As 20 percent of Kenya’s population — eight million people — living in the highland areas are now exposed to malaria, new plans for preparing and responding to an epidemic are needed” (Inter Press Service News).
In The Lancet article O’Meara and colleagues believe that the reduction in transmission in coastal Kilifi is multi-factorial and could be related to bednet use and changes in malaria drug policy among others. They conclude that, “Our results are consistent with comparisons between multiple sites and provide further evidence that reduction of trans mission leads to a change in pattern of severe disease but might not lead to immediate reductions in disease burden.” This means that …
Emphasis on use of insecticide-treated bednets, early treatment, and other control measures must be increased to maintain reductions in disease burden and prevent a potential resurgence of malaria in a population with far less immunity than before.
The experience in Kenya shows that changing climatic conditions and increasing effectiveness of malaria control interventions may in the short run put more people at risk of severe malaria due to reduced immunity levels. The need for sustaining efforts in some parts of the country and focusing new interventions on others makes the elimination of malaria a challenging and ever shifting target.