Malaria Outbreak Along the Thai-Myanmar Border: A Situation Update
Thailand continues to face the spread of malaria, particularly along its western border. The country has been implementing the National Malaria Elimination Strategy 2017-2026 in collaboration with international organisations such as the World Health Organization (WHO), the United States Agency for International Development (USAID), the Asia Pacific Leaders Malaria Alliance (APLMA), and the University of California, San Francisco (UCSF), as well as various partner networks. This collaboration has enabled Thailand to achieve malaria-free status in several areas.
In 2024, despite some provinces having previously been declared malaria-free, a resurgence of the disease has been observed, particularly in the areas bordering Thai-Myanmar, where increased migration has led to a rise in the number of patients. Therefore, Division of Vector Borne Diseases, under Department of Disease Control, Ministry of Public Health, has collaborated with USAID and various partner networks to reduce the spread and eliminate malaria in this region sustainably.
Data from the Department of Disease Control indicates that in 2023, 42 provinces in Thailand met the criteria for malaria-free status. However, malaria transmission was still detected in 35 provinces. Among these, 7 provinces that were previously declared malaria-free experienced a re-emergence of cases: Chaiyaphum, Phuket, Phitsanulok, Lamphun, Kamphaeng Phet, Saraburi, and Suphan Buri. Meanwhile, 28 provinces continued to experience ongoing malaria transmission in 2023: Mae Hong Son, Chiang Mai, Tak, Phetchabun, Uthai Thani, Ratchaburi, Phetchaburi, Kanchanaburi, Prachuap Khiri Khan, Chumphon, Ranong, Surat Thani, Phang-nga, Krabi, Songkhla, Yala, Narathiwat, Ubon Ratchathani, Sisaket, Chon Buri, Trat, Chanthaburi, Sa Kaeo, Chachoengsao, Mukdahan, Surin, Nakhon Ratchasima, and Nan.
The malaria situation along the Thai-Myanmar border following the conflict in Myanmar and the migration into Thailand along the border, such as in Ranong province, has seen a significant increase. While the province typically records around 10 malaria patients annually, the number has risen to hundreds in 2024. The primary vector in the border areas is the Anopheles mosquito, and delays in identifying patients can lead to further transmission. Therefore, caution and personal protection are crucial. Regarding the transmission from forest to urban areas, entomological research teams have not yet found evidence of Anopheles mosquitoes transmitting the parasite to urban mosquito species. Several factors contribute to the higher risk of malaria infection among people in the border areas compared to other regions. These include fleeing the unrest in Myanmar, which involves travelling through high-risk forested areas before crossing into Thailand, and working in agricultural areas with prolonged outdoor exposure. Additionally, migrant patients often do not receive continuous medical treatment due to limitations related to their legal status. These factors make disease control and prevention challenging.
Government Efforts to Control Malaria
The malaria prevention plan covers all provinces along the border, and provinces not located along the border also have disease-free plans. This is implemented through the 1-3-7 measure, which has key operational principles: alerting within 1 day upon detection of a patient, tracing their history to identify the source of infection within 3 days, and responding to the situation within 7 days, along with controlling the mosquito vectors in the outbreak area and accelerating proactive case finding to ensure effective treatment and prevent recurrence.
In controlling malaria among migrant populations, Division of Vector Borne Diseases categorises migrants into two groups. Group 1 consists of migrants residing in Thailand for more than 6 months (Migrant Type 1 or T1), and Group 2 comprises migrants staying in Thailand for less than 6 months or frequently crossing the border (Migrant Type 2 or T2). Division of Vector Borne Diseases has found that Group 2 represents the majority of migrants testing positive for the malaria parasite. Therefore, they emphasise collaboration with security officials in border areas to facilitate safe border crossings, enabling testing while avoiding punitive legal measures. Due to concerns about their legal status, a significant number of migrants do not receive formal testing and treatment, opting instead for informal remedies, which complicates disease control efforts. Although Thai citizens and migrant populations are under the same malaria control strategy, the government must collaborate with civil society organisations in the area, such as World Vision Thailand, which operates in Tak and Mae Hong Son provinces, to effectively reach migrant communities. This is because World Vision Thailand has gained the trust of the communities and can connect with target groups that are difficult for the government to access.
World Vision Thailand’s Support for Government’s Malaria Control Efforts
Through the Regional Artemisinin-resistance Initiative 4 Elimination Program, supported by the Global Fund, UNOPS, Department of Disease Control and Raks Thai Foundaton, World Vision Thailand supports 11 Border Malaria Education and Consultation Corner (BorMECC) in Tak and Mae Hong Son Provinces, which provide rapid testing, referral, education along with preventive equipment, and follow-up care for migrants. In 2024, World Vision Thailand had facilitated the testing and referral of more than 45,000 migrants and distributed 36,250 mosquito nets to migrant communities. However, students remain the second most-infected group behind daily laborers, as they’re often taken out of school to work in cornfields during harvest season, where malaria risks are higher. Some students travel back to their homes in Myanmar and then return to continue their studies in Thailand.
World Vision Thailand’s Community Field Officers (CFOs) work closely with the government, while migrant health volunteers (MHVs) facilitate community outreach, education, and translation during case investigations. MHVs are instrumental in building relationships within migrant communities, allowing for better community testing and active case finding. Supervised by CFOs, MHVs provide follow-up care via phone and in-person visits to ensure patients complete their full 14-day treatment course (Plasmodium vivax), which protects against reinfection for three months and helps to prevent drug-resistant especially Plasmodium falciparum (3-day antimalarial regimen). World Vision Thailand’s close collaboration with local employers and community leaders has also been key to encouraging migrants to seek testing and treatment.
Key Learnings and Adaptations
World Vision Thailand and Division of Vector Borne Diseases have learned that after-hours availability in communities has allowed both organizations to reach significantly more people with testing and mosquito nets, as many migrants have work commitments and would otherwise not be able to receive care. World Vision Thailand staff and MHVs are also now instructed to share the GPS locations of cases with Division of Vector Borne Diseases response teams, enabling rapid deployment to investigate and contain outbreaks. For instance, if multiple cases are linked to a particular farm, the response team can now quickly inspect the site for mosquito breeding areas. Lastly, World Vision Thailand incentivizes participation by providing snacks during rapid testing and net distribution community events, which the Division of Vector Borne Diseases reports has considerably boosted attendance.
