Epidemiology of Malaria in Ubon Ratchathani, Thailand

Study sites and enrollment:

Patients self-presenting to (1) health centres or(2) malaria posts or (3) district hospitals in Buntharik District and Nachalui District, Ubon Ratchathani Province, Thailand and requiring a diagnostic test for malaria as determined by the treating clinician will be recruited. Those who are malaria positive will be candidate cases and those who are malaria negative will be candidate controls.

One-to-one matching of cases and controls will be done at each study site. One control will be matched to each case. The matching criteria will be the next malaria negative patient to attend the study site of the same gender and age+/-5 years as an enrolled malaria positive case.

Study procedure:

CASE (Malaria patient defined by positive RDT or blood smear)

Upon enrollment, the below study procedures will be followed;

1. Blood samples consisting of:

   • Three dried blood spots
   • A microscopy slide
   • In the district hospitals only, 10 ml of venous blood will be taken from the positive for malaria patient.
2. A survey include patient demographics, information on malaria treatment, bed net use and possible risk factors for acquiring malaria, as well as questions about their travel and usage of mobile phone will be administered to each patient.

CONTROL (Non-malaria patient defined by negative RDT or blood smear)

Upon enrollment, for those negative for malaria, the below study procedures will be follows;

1. Blood samples consisting of:

   • Blood smear
   • In the district hospitals only, 0.5 ml of venous blood will also be collected.
2. A survey include patient demographics, information on malaria treatment, bed net use and possible risk factors for acquiring malaria, as well as questions about their travel and usage of mobile phone swill be administered to each patient.

CASE: Follow-up

• If patients develop a fever after the end of antimalarial treatment and within 42 days after enrollment, they will be asked to return for follow-up as soon as possible on one occasion and then again at 42 (+/-3) days.
• If they do not develop fever within 42 days after enrollment, they will be asked to return for follow up at 42 (+/-3) days.

At the follow-up visit, blood will be taken to test for malaria by microscopy, three dried blood spots will be taken and a short survey administered including questions on symptoms, travel and possible risk behaviors since enrollment.

*In the district hospitals only, 1.5ml of venous blood will be taken

CONTROL: No follow up