Trends in Parasitology
OpinionNovel Approaches to Control Malaria in Forested Areas of Southeast Asia
Section snippets
Spreading Multidrug Resistance Adds Urgency to Elimination
Between 2000 and 2017 the malaria burden in the Greater Mekong Subregion (GMS; see Glossary) has decreased in a heterogeneous fashion (Figure 1). China succeeded in interrupting endogenous malaria transmission by 2017 [1]. Close monitoring, rapid case investigation, reporting, and response played critical roles in this success [2]. In Myanmar, the country with the highest malaria burden, the number of reported malaria cases dropped below 100 000 only in 2017. Two studies published in 2018
Concentration of Malaria Transmission in Forested Areas of the GMS
The importance of forests in malaria transmission in Indochina was well established in the 20th century [5]. With better malaria control in residential areas the relative importance of the still poorly controlled transmission of malaria in forested areas has increased. By 2019 malaria transmission is concentrated in the forested areas of Cambodia, Myanmar, Laos, and Vietnam. As shown in multiple studies, the population at highest risk for malaria in the GMS are adults who work in forested areas
Current Malaria Prevention Methods Used by Forest Workers
Forest workers use a range of malaria prevention strategies [22]. Wearing long-sleeved shirts, trousers and socks can reduce mosquito bites but can be unbearably hot in tropical forests 23, 24, 25. Forest workers rely on mosquitoes avoiding smoke by starting fires around their work and campsites 26, 27, 28. Smouldering mosquito coils releasing spatial repellents such as pyrethrins can kill or at least knock down mosquitoes and are worn by forest workers in a portable coil holder or attached to
Concluding Remarks
In the GMS, malaria is predominantly a disease in adults who become infected during outdoor work in forested areas. The currently available vector-control measures, including insecticide spraying and treated bed nets, have little effect on mosquitoes that preferentially bite outdoors and during daytime. To eliminate malaria from the GMS it is essential to stop malaria transmission in forested areas in addition to already ongoing malaria-elimination efforts. Antimalarial prophylaxis for forest
Acknowledgments
We are indebted to our colleagues who helped the development of this paper in many discussions over the years.
Glossary
- Artemisinin combination therapy (ACT)
- is the combination of an artemisinin derivative with a partner drug. The artemisinin component reduces the number of susceptible parasites during the first 3 days of treatment (reduction of parasite biomass), while the role of the partner drug is to eliminate the remaining parasites, including artemisinin-tolerant parasites. ACTs fail when both partner drugs no longer clear the parasites. The spread of parasites resistant to artemisinin derivatives and
References (84)
Effect of generalised access to early diagnosis and treatment and targeted mass drug administration on Plasmodium falciparum malaria in Eastern Myanmar: an observational study of a regional elimination programme
Lancet
(2018)Changing patterns of forest malaria among the mobile adult male population in Chumkiri District, Cambodia
Acta Trop.
(2008)Deviance and resistance: malaria elimination in the greater Mekong subregion
Soc. Sci. Med.
(2016)Efficacy of topical mosquito repellent (picaridin) plus long-lasting insecticidal nets versus long-lasting insecticidal nets alone for control of malaria: a cluster randomised controlled trial
Lancet Infect. Dis.
(2016)Prevention of malaria in pregnancy
Lancet Infect. Dis.
(2018)Seasonal malaria chemoprevention in the Sahel
Lancet Infect. Dis.
(2017)New tools for malaria control − using them wisely
J. Infect.
(2017)- et al.
Treatment of acute vivax malaria with tafenoquine
Trans. R. Soc. Trop. Med. Hyg.
(2005) The spread of artemisinin-resistant Plasmodium falciparum in the Greater Mekong Subregion: a molecular epidemiology observational study
Lancet Infect. Dis.
(2017)Does antimalarial mass drug administration increase or decrease the risk of resistance?
Lancet Infect. Dis.
(2017)
Spread and evolution of Plasmodium falciparum drug resistance
Parasitol. Int.
Malaria protection in Sierra Leone during the Ebola outbreak 2014/15; The UK military experience with malaria chemoprophylaxis Sep 14–Feb 15
Travel Med. Infect Dis.
Malaria control strategies in French armed forces
Travel Med. Infect Dis.
Cytochrome b mutation Y268S conferring atovaquone resistance phenotype in malaria parasite results in reduced parasite bc1 catalytic turnover and protein expression
J. Biol. Chem.
Randomised trial of pyronaridine versus chloroquine for acute uncomplicated falciparum malaria in Africa
Lancet
Ready for malaria elimination: zero indigenous case reported in the People’s Republic of China
Malar. J.
Communicating and monitoring surveillance and response activities for malaria elimination: China’s ‘1-3-7’ strategy
PLoS Med.
Malaria elimination in remote communities requires integration of malaria control activities into general health care: an observational study and interrupted time series analysis in Myanmar
BMC Med.
Malaria in central Vietnam: analysis of risk factors by multivariate analysis and classification tree models
Malar. J.
Epidemiology of forest malaria in Central Vietnam: the hidden parasite reservoir
Malar. J.
Risk factors for malaria infection among ethnic minorities in Binh Phuoc, Vietnam
Southeast Asian J. Trop. Med. Public Health
Epidemiology of forest malaria in central Vietnam: a large scale cross-sectional survey
Malar. J.
‘I could not join because I had to work for pay.’: a qualitative evaluation of falciparum malaria pro-active case detection in three rural Cambodian villages
PLoS One
Forest goers and multidrug-resistant malaria in Cambodia: 1. An ethnographic study
Am. J. Trop. Med. Hyg.
Forest Change in the Greater Mekong Subregion (GMS): An Overview of Negative and Positive Drivers
Myanmar’s forests still being illegally logged and shipped to India, China, despite government ban
South China Morning Post
Affordable house designs to improve health in rural Africa: a field study from northeastern Tanzania
Lancet Planetary Health
Poverty and malaria: a study in a Thai–Myanmar border area
Southeast Asian J. Trop. Med. Public Health
Social and cultural aspects of malaria
Southeast Asian J. Trop. Med. Public Health
A review of malaria transmission dynamics in forest ecosystems
Parasit. Vectors
Cow-baited tents are highly effective in sampling diverse Anopheles malaria vectors in Cambodia
Malar. J.
Malaria ecology along the Thailand–Myanmar border
Malar. J.
How can interventions that target forest-goers be tailored to accelerate malaria elimination in the Greater Mekong Subregion? A systematic review of the qualitative literature
Malar. J.
High mobility and low use of malaria preventive measures among the Jarai male youth along the Cambodia–Vietnam border
Am. J. Trop. Med. Hyg.
Acceptability of insecticide-treated clothing for malaria prevention among migrant rubber tappers in Myanmar: a cluster-randomized non-inferiority crossover trial
Malar. J.
The use of personal protective measures in control of malaria in a defined community
Southeast Asian J. Trop. Med. Public Health
Mass anti-malarial administration in western Cambodia: a qualitative study of factors affecting coverage
Malar. J.
Positive deviance as a novel tool in malaria control and elimination: methodology, qualitative assessment and future potential
Malar. J.
Impact of a spatial repellent on malaria incidence in two villages in Sumba, Indonesia
Am. J. Trop. Med. Hyg.
Malaria risk factors and care-seeking behaviour within the private sector among high-risk populations in Vietnam: a qualitative study
Malar. J.
Cited by (33)
Antimalarial chemoprophylaxis for forest goers in southeast Asia: an open-label, individually randomised controlled trial
2023, The Lancet Infectious DiseasesCitation Excerpt :In Cambodia, malaria incidence has reached very low levels, with fewer than 5000 cases reported in 2021, of which around 90% were caused by Plasmodium vivax and 10% by P falciparum.4 In much of the Greater Mekong subregion, including Cambodia, the remaining malaria transmission is concentrated in forested areas.5,6 Addressing the remaining parasite reservoir in forest goers is essential to reach the goal of malaria elimination within the proposed time frame.7
Presence and abundance of malaria vector species in Miami-Dade County, Florida
2024, Malaria JournalPresence and Abundance of Malaria Vector Species in Miami-Dade County, Florida
2023, Research Square