We are a research group from the London School of Hygiene and Tropical Medicine

The purpose of this project is to map the geographical distribution of resistance mutations in African Plasmodium falciparum malaria. We have reviewed all genetic studies of resistance to Sulphadoxine Pyrimethamine (also known as ‘SP’ or ‘Fansidar’) in parasites sampled from infected people living in clearly identified geographical sites in Africa. Static maps which summarise the distribution of particular mutations have been published (Lynch et al 2008, Gesase et al 2009, Naidoo and Roper 2010, Naidoo and Roper 2011, Okell et al 2017) and here they are available as interactive Google maps. The interactive maps are regularly updated and so they incorporate some studies that have become available since publication of these papers.

Literature review

We conducted a review of published studies using the online databases Pubmed, African Journal Online and Bioline. Electronic searches using the terms: "malaria" "dhfr" "dhps" or "540" or "437" or "436" or "581" or 51 or 59 or 108 or 164 were carried out between October 2005 to February 2011. . In March 2016, we updated the review of the 540E and 581G mutations. To be included, studies had to include analysis of dhfr or dhps genes in P. falciparum isolates sampled from infected people living in a clearly identified geographical site in Africa.

Mapping

We attached a longitude and latitude to each study site and plotted these data on Google maps for each of a number of the key mutations. In the maps the user can zoom in or out, or select by country. Each record on the map records: the number of samples tested and the number found positive for that particular mutation, the year of sample collection, the author and year of the publication and a link to the online publication source. For studies where we could not ascertain the year of sampling, the year of publication is given (eg <2005). ‘Prevalence’ is the proportion of the total number of samples tested in which the mutation was detected. We have colour coded map pins into five prevalence categories namely 0 (white),1-25% (blue), 26-50% (green), 51-75% (brown) and 76-100% (red).