This study is to determine the prevalence and geographical distribution of antimalarial drug resistance-linked genetic mutations in clinical P. falciparum infections in Cambodia

This is a prospective observational study of patients with clinical Plasmodium falciparum infection using parasite DNA from point-of-care fingerprick dried blood spot samples as well as a short survey on patient demographics, employment, travel, and mobile phone use to study P. falciparum parasite genotypes, population characteristics, and gene flow patterns.

On inclusion in the study and before standard treatment is administered, dried blood spots (DBS) will be obtained through fingerprick blood sampling from patients, with three blood spots on one piece of filter paper being obtained from each patient. Each blood spot will contain ~20µl of blood, for a total of ~60µl of blood being collected from each patient for the study.

In order to have a greater understanding of the possible sites of malaria transmission and to relate genetic diversity to geographic location, patients or their parents/guardians will also be asked a short set of questions on demographics, their places of residence and work, recent mobile phone use, and their history of travel in the last 2 months. As some of this information can be sensitive, during the consent process the patient will be given the option of not providing some or all of this information without needing to provide a reason. This is explained on the patient information sheet. For those who do not want to provide information, this will be documented in the survey form. A duplicate of the sample barcode will be placed on this same form, so the information therein can be matched with the relevant blood spot and its related genetic data, while retaining sample anonymity.

Inclusion Criteria:

• Male or female >6 months of age
• P. falciparum malaria as confirmed by positive rapid diagnostic test or asexual forms of P. falciparum on blood smear microscopy (may be mixed with non-falciparum Plasmodium species)
• Written informed consent by patient, parent/guardian, or legally authorised representative to participate in the study

Exclusion Criteria:

• None

Patients > 6 months of age with P. falciparum malaria who present to village malaria workers and health centres in Stung Treng and Ratanakiri provinces in Cambodia are the target study population. 2014 data suggest this could amount to up to 7,000 patients per year. All study participants must satisfy the applicable inclusion and exclusion criteria

Anonymised data recorded in the CRFs will be shared via open access online repositories as per the requirements of the journal in which the results of the study are published.