Vivax malaria patients and their drug adherence in northern Thailand

Vivax malaria is a significant cause of malaria morbidity in Northern Thailand, accounting for approximately 50% of all malaria cases. Although the standard treatment regimen is effective, compliance is low. Therefore, we conducted a cross-sectional survey among 206 malaria patients who were diagnosed with vivax malaria infection in Muang and Mae Sarieng Districts, Maehongson Province, northern Thailand. The purpose of this study was to determine factors related to the adherence of the standard 14-day course of chloroquine and primaquine in vivax malaria patients. Data was collected using a structured interviewer-administered questionnaire as well as focus group discussions. Overall, 76.2% of vivax malaria patients did not adhere to the complete medication course and only 23.8% completed the entire course. According to univariate analysis, patient adherence was associated with knowledge scores of malaria (OR=2.08, 95% CI=1.02-4.3), perception scores of malaria (OR=2.33, 95% CI=1.14-4.86) and personal behaviors of drug taking scores (OR=5.59, 95% CI=2.04-18.94). After multivariate analysis, patient adherence was still significantly associated with knowledge scores of malaria (aOR=2.35, 95% CI=1.18-4.69), and personal behavior scores (aOR=6.09, 95% CI=2.26-16.42). Focus group interviews revealed that patients neglected to take drugs on time and regularly due to occupational time constraints. Furthermore, side effects (nausea and vomiting from chloroquine in the first three days) troubled the patients, which led many to cease the medication course after three days. In the future, Information Education and Communication (IEC) programs at malaria clinics, specifically targeting these factors, must be initiated to educate vivax patients to comply with treatment.