I travel to Kenya this weekend, so naturally in Malaria World my attention was drawn to ‘Malaria prevalence, transmission potential and efficacy of artemisinin-based combination therapy in the Kenyan Central highlands: a zone previously characterized as malaria-free’ by Kimani et al. This is a large study with many components carried out in Kikuyu sub-county of Kiambu County, Kenya located about 20km Southwest of Nairobi, part of the Kenyan Central highlands.
In included mosquito sampling in houses and of larvae in swamps (see picture). It included non-randomized 28 day, uncontrolled clinical follow up with one treatment arm to assess the efficacy of artemether-lumefantrine (AL). Blood was examined for plasmodium parasites. They looked for ACT (artemisinin combination therapy) resistance markers using gene analysis.
And the results. Only two adult Anopheles mosquitos were collected indoors from 30 houses over three nights (and in the one house). And they were negative for plasmodia. More were hatched and reared from larvae collected in the swamps (148 female Anopheles).
In the hospital just 5.6% of 838 patients with malaria symptoms had positive slide results for plasmodia. All received a dose of the drug.
The authors do conclude that the positivity rate was very low. However, they interpret the results as presenting a changing situation that may require further research. They did conclude that the parasites were susceptible to the drug.
I must admit I found this research very underwhelming. The area of Kenya examined was not the North East like Busia near Lake Victoria I discussed last week that has more malaria. It is convenient to Nairobi for the KEMRI researchers. I suspect if a similar study were carried out practically anywhere it would find similar numbers of Anopheles and similar level of plasmodia in patients with malaria symptoms. Or maybe even more. There have been no major outbreaks of malaria in this region since 1980s and 1990s, just anecdotal reports that residents of the area have been treated for malaria. And malaria is an illness with symptoms common to many other ailments.