Transmission characteristics
Around 3.6 million people are at risk of contracting malaria in Laos from a population of 6.9 million. In 2022, there were 2,272 reported malaria cases (falciparumI, vivax, and mixed).1
There are four recognised malaria vectors in Lao PDR: Anopheles dirus, An. minimus, An. maculatus, and An. jeyporiensis. While An. minimus is widespread and has been identified in all provinces, An. dirus is most common in the central and southern part of the country and is considered rare in the north. The intensity of malaria transmission varies between different ecological zones: from very low transmission in the plains along the Mekong River and in areas of high altitude, to intense transmission (API>30) in the remote, forested areas of the south. Peak transmission season occurs October–February.2 Groups at greatest risk include ethnic minorities, forest-related and agricultural workers, and miners.2 Traditional forest inhabitants belong to over 57 different ethnic groups, many with their own language and often living in remote areas in severe poverty with limited access to government healthcare.2 In this case, all age groups are exposed to transmission, with pregnant women and children most vulnerable.2 In forest fringe communities, adult men are most at risk of malaria due to overnight visits to hunt for food or collect wood. Temporary migrants to the forest, such as miners and construction workers are usually adult males with limited immunity to malaria. New forest settlers are initially at high risk of malaria, though transmission generally wanes following development and deforestation.2
Surveillance
The national disease surveillance system is being upgraded to facilitate information-sharing and rapid response to the developing dynamics of malaria transmission. This includes the rollout nationally of the District Health Information System 2 (DHIS-2) platform. Strengthening of surveillance is needed to respond to all outbreaks, to identify foci and to support malaria elimination.1
2020 milestones/ malaria elimination
Lao PDR achieved its milestones of at least a 40% reduction in malaria mortality and case incidence in 2010 and remains on track to retain these gains for 2020.1
The Malaria National Strategic Plan (2016–2020) is the first part of a three-phase approach to eliminate all forms of non-zoonotic human malaria in Laos and includes strengthened interventions targeted to the southern part of the country to reduce the primary malaria burden while beginning efforts to eliminate malaria in the remaining focal areas in central and northern provinces.1 By 2025, the country targets elimination of P. falciparum malaria and P. vivax from all Northern provinces and elimination of P. falciparum in the four southernmost provinces. National malaria elimination is envisioned by 2030.1
Lao PDR is included in the Mekong Malaria Elimination (MME) Initiative in the Greater Mekong subregion, supported through a Global Fund financed regional artemisinin-resistance initiative, which aims to eliminate P. falciparum by 2025 and all species of malaria by 2030.1
Treatment policy for P. vivax
• First-line is artemether-lumefantrine followed by 14-day primaquine for radical treatment of P. vivax. Chloroquine is second line.3
• Diagnosis and treatment is free of charge in the public sector.
G6PD testing policy
G6PD testing is recommended before treatment with primaquine.3
G6PD deficiency prevalence
There are limited reports on G6PD deficiency prevalence in Lao PDR, with prevalence ranging between 3% and 31% in males. G6PD Viangchan appears to be the most prevalent G6PD-deficient variant. Note that there are 50–60 distinct ethnic groups which may vary in the prevalence and severity of G6PD deficiency, though data comparing these groups are not available.
1 Thailand, LAO PDR and Regional Malaria Operational Plan 2018: USAID: Washington, DC, 2018.
2 National Strategy for Malaria Control and Pre-elimination (2011–2015): Ministry of Health, Lao People’s Democratic Republic: Vientiane, 2010.
3 World Malaria Report 2018