Arboshield Plus
Collaboration.
Institute for Disease Prevention, Ministry of Defense, Lao PDR
Military Hospitals, Ministry of Defense, Lao PDR
Funding.
Defense Threat Reduction Agency (DTRA), USA.
Objectives.
The objective of the Arboshield Plus project is to strengthen the capacity of the medical sector of the Ministry of Defense and of some of the selected civilian hospitals under the Ministry of Health, Lao People’s Democratic Republic (Lao PDR).
The project is articulated around vector-borne diseases and includes various aspects such as surveillance, outbreak detection/response, diagnosis, treatment, prevention, as well as biosafety and security through training and improving hospital facilities. The role of the Parasitology lab in this project is to provide training courses on malaria for the trainees from military and civil sectors, to implement quality assessment of malaria diagnosis in the Lao Institute for Disease Prevention and six military provincial hospitals (Xieng Khouang, Luang Prabang, Vang Vieng, Vientiane Capital, Savannakhet, and Champasak), which participate in the Arboshield Plus project.
Background.
The medical military sector in Lao PDR offers its services to a significant proportion of the military and civilian Lao population. The Lao Ministry of Defense has a medical institute in Vientiane’s capital and several hospitals across the country. Unfortunately, the Lao Ministry of Defense receives limited external support to improve its capacity and facilities despite the fact that several studies reported that soldiers were at high risk for malaria infection because they patrol and stay in the forests where malaria and other vector-borne diseases are highly prevalent [1,2]. Moreover, one of our previous studies found household clustering of asymptomatic malaria infections which indicates that malaria is also transmitted by Anopheles mosquito within the members of a family [3]. These results suggested that even though malaria is nowadays not frequently transmitted in villages, malaria can be introduced in households by family members who work and stay in the forests.
Methodology.
To strengthen the capacity of the medical sector of the Lao Ministry of Defense, IPL’s team provided a series of lectures (biosafety, biosecurity, waste management, disease surveillance, medical entomology, field epidemiology, etc.) and on-the-job laboratory training at all IPL’s laboratories for 6 months (one trainee per lab).
The parasitology laboratory also supported a quality assurance program on malaria diagnosis for the military hospitals. Dried blood samples obtained from suspected patients were collected on filter papers and sent to the Parasitology lab at IPL; PCR for malaria detection was performed to confirm the diagnosis made by the military hospitals. For the malaria PCR, universal PCR primers for human malaria parasite detection were used for the primary PCR. Species-specific PCR primers (Plasmodium falciparum and P. vivax) were used for the secondary PCR.
Results.
In the frame of the quality assurance program, the Parasitology laboratory analyzed blood samples collected from malaria-suspected patients in military hospitals by the nested real-time PCR. By September 2023, a total of 166 blood samples were received by the Parasitology lab at IPL (Table 1). All the samples tested negative for malaria DNA detection.
Detailed results can be found in the paper version of this report and in upcoming publications.
Discussion.
Currently, the province with the highest number of reported malaria cases is Attapeu Province. Unfortunately, Attapeu Provincial Military Hospital is not included in the Arboshield Plus project. The total number of malaria cases in Lao PDR rapidly decreased in 2023 compared to 2022. However, a malaria outbreak due to P. vivax (n=231 cases) was reported in Nakai district, Khammouane province, in June-August 2023 where only one malaria case was reported from January 2022 to May 2023.
The Lao Ministry of Health, WHO and IPL started the investigation of the malaria outbreak in Khammouane province to elucidate whether the parasites were circulating in the community for several months without detection or if the parasites were introduced from other endemic area(s) by movement of human or mosquito populations.
Decreased immunity of the population to malaria and reduced attention to malaria among healthcare workers in elimination settings are other risk factors for malaria outbreaks that should be considered. To achieve malaria elimination in Lao PDR by 2030, extensive surveillance, vector control, appropriate case management and response should be maintained in the whole country. The reintroduction of malaria into a malaria-free provinces should also be closely monitored to prevent the re-establishment of malaria transmission like the Nakai district, Khammouane province in 2023.
Conclusion & Perspectives.
The total number of malaria cases among the Lao Military personnel is decreasing which is a good sign for malaria control and elimination in Lao PDR. However, our surveillance does not include all the military hospitals from all the provinces. To achieve malaria elimination in Lao PDR by 2030, further surveillance and effective interventions are needed at the whole country level.
References.
1. Iwagami M, Keomalaphet S, Khattignavong P, Soundala P, Lorphachan L, Matsumoto-Takahashi E, Strobel M, Reinharz D, Phommasansack M, Hongvanthong B, Brey PT, Kano S. The detection of cryptic Plasmodium infection among villagers in Attapeu province, Lao PDR. PLoS Neglected Tropical Diseases, 11(12): e0006148, 2017.
2. Vilay P, Nonaka D, Senamonty P, Lao M, Iwagami M, Kobayashi J, Hernandez PM, Phrasisombath K, Kounnavong S, Hongvanthong B, Brey PT, Kano S. Malaria prevalence, knowledge, perception, preventive and treatment behavior among the military in Champasak and Attapeu provinces, Lao PDR: a mixed methods study. Tropical Medicine and Health, 47:11, 2019.
3. Pongvongsa T, Nonaka D, Iwagami M, Nakatsu M, Phongmany P, Nishimoto F, Kobayashi J, Hongvanthong B, Brey PT, Moji K, Mita T, Kano S. Household clustering of asymptomatic malaria infections in Xepon district, Savannakhet province, Lao PDR. Malaria Journal, 15(1): 508, 2016.
