Imported and autochthonous malaria in West Saudi Arabia: results from a reference hospital

The Kingdom of Saudi Arabia is seeking malaria eradication. Malaria transmission has been very low over the last few years. Discovered cases of Plasmodium falciparum infection are assigned a treatment protocol of artemisinin-based combination therapy, which consists of artesunate in addition to sulfadoxine-pyrimethamine rather than the traditional chloroquine, which has high resistance rates worldwide. This study aims to investigate the presence of different gene mutations concerning anti-malarial drug resistance (pfdhfr, pfdhps, pfmdr1, pfcrt, pfcytb, pfkelch13) to identify whether drug-resistant alleles are present in this area of the Kingdom and whether the country's treatment protocol is still suitable for Plasmodium bearing a resistance mutation [corrected].

Blood samples were collected from patients suffering from symptoms suggesting malaria coming to King Faisal Hospital, Taif, from February to August 2016. Diagnosis was performed by Giemsa-stained thin and thick blood films, rapid diagnostic test and PCR. Positive P. falciparum samples were further subjected to series of PCR amplification reactions targeting genes related with drug resistance (pfdhfr, pfdhps, pfmdr1, pfcrt, pfcytb, pfketch13).

Twenty-six cases were positives, 13 infected with P. falciparum, of those, 4 cases were autochthonous, and 13 with Plasmodium vivax. The results of the gene mutation detection confirmed that there was no mutation related to resistance to artemisinin or atovaquone, on the other hand chloroquine resistance alleles were detected in 31% of samples. Moreover, point mutations in the pfdhfr and pfdhps genes, related resistance to antifolate drugs, were detected in all characterized samples.

Haplotypes of P. falciparum in the western region of the Kingdom of Saudi Arabia exhibit high resistance against antifolate drugs. These results should be extensively discussed when planning to modify anti-malarial drug protocols in the future.