SATREPS project

Title: Project for Malaria and Neglected Parasitic Diseases Control and Elimination using Advanced Research Technique, Communication tools and Eco- Health Education

Principal Investigator
Dr. Moritoshi Iwagami

Partners In Laos:
Center of Malariology, Parasitology and Entomology (CMPE), Department of Communicable Disease Control (DCDC), Lao Tropical and Public Health Institute (Lao TPHI), University of Health Sciences (UHS), Faculty of Education, National University of Laos, and some other relevant departments and centers in Ministry of Health (MOH), Ministry of Education and Sports (MOES) and Ministry of Agriculture and Forestry (MAF)

In Japan: National Center for Global Health and Medicine (NCGM), Tokyo Medical and Dental University (TMDU), Niigata University, Dokkyo Medical University (DMU), University of the Ryukyus (UR), The University of Tokyo (UT), Shinshu University (SU), Kumamoto University (KU)

Period: 2023-2028

Study areas:
Savannakhet, Salavan, Sekong, Champasak, and Attapeu provinces

Background and objectives

Science and Technology Research Partnership for Sustainable Development (SATREPS) is a Japanese government program that promotes international joint research for global issues, such as infectious disease control, energy/environment issues, disaster risk reduction, and food security.

Malaria is endemic in five southern provinces in Lao PDR which means 2.6 million people (35.3% of population) are at risk of the infection. Morbidity and mortality of malaria have decreased in Lao PDR by the efforts of the Lao Government with support of partners. The Government has adopted a goal of malaria elimination by 2030. However, several obstacles such as drugresistant malaria, asymptomatic or low-density malaria infections, poor access to healthcare services in the remote hard-to-access villages are reported. Neglected Tropical Diseases (NTDs), especially parasitic diseases have been neglected in Lao PDR. According to the Lao National Policy and Strategies on NTDs Prevention and Control, schistosomiasis mekongi, foodborne-parasitic diseases, soil-transmitted helminthiasis and lymphatic filariasis are listed. These diseases have received less attention because they are chronic disease and endemic only in low-income countries. However, the impact of such NTDs is devastating both from a public health and economic point of view for the affected people. Project objectives are to achieve malaria elimination, and control neglected parasitic diseases (NPDs), such as schistosomiasis mekongi, opisthorchiasis in Lao PDR.

For malaria control, low-density malaria infection which cannot be detected by the current malaria-diagnostic methods (rapid diagnostic test, microscopy) is a major obstacle for malaria elimination.

Therefore, a highly-sensitive DNA-diagnosis: malaria- LAMP-testing will be installed at local-healthcarefacilities (i.e., district hospitals) as a point-of-care testing and utilized for detecting low-density malaria infection. Thus, the malaria LAMP-testing enables to diagnose all malaria patients (No one left behind) and provides appropriate treatment for them. We have already evaluated a performance of this LAMP-testing using clinical samples in Lao PDR. Drug resistant malaria will also be monitored by in vitro drug-susceptibility test. Currently, most of malaria cases are reported from remote hard-toaccess villages where no mobile phone signal is available. In such areas, out of stock malaria commodities are often reported due to a delay of reporting and procurement. Thus, satellite-mobile phones will be distributed at such healthcare-facilities (i.e., health centers) to improve malaria surveillance.

For NPDs control, we developed a real-time PCR with environmental DNA (eDNA) technic for schistosomiasis and opisthorchiasis. However, the real-time PCR cannot be performed at local-healthcare-facilities. Therefore, LAMP-testing with eDNA technic will be developed for schistosomiasis and opisthorchiasis, and infection risk maps will be created for infection prevention. For preventing opisthorchiasis, a novel pulsed-power technology for inactivation of Opisthorchis viverrini metacercariae in freshwater-fish will be developed and installed at fresh-market(s) in Lao PDR. This technology was developed by Kumamoto University, Japan and has already utilized as a sea-fish parasite (anisakis) inactivation measure in Japan since 2021. For schistosomiasis mekongi and opisthorchiasis prevention, a special-food for the snail hosts to reduce the number of S. mekongi cercaria and O. viverrini cercaria will be developed. An efficacy to reduce the number of S. mansoni cercaria was proved at laboratory setting at Tokyo Medical and Dental University (TMDU).

Most of malaria and NPDs patients are ethnic minorities who live in remote hard-to-access villages and live in poor hygiene conditions which are at the risk of several infectious diseases. Therefore, ecohealth education for residents of the endemic areas including ethnic minorities will be developed and conducted for improving their knowledge and capacity for preventing malaria and NPDs and health-seeking behavior. “Ecohealth education” is based on systems thinking focused on ecosystems; that is, ‘ecosystem-thinking’, which emphasizes an understanding of the whole ecosystem from multiple perspectives that considers mutually dependent relationships.

By implementing this project, the numbers of malaria and NPDs cases will be expected to decrease in Lao PDR. The project will contribute to achieve Universal Health Coverage (UHC) and Goal 3 of the Sustainable Development Goals (SDGs).

Outputs

The Outputs of the Project are described as follows:

(1) Accurate diagnosis of malaria, including asymptomatic malaria parasite infection and low-density malaria parasite infection, is conducted in malaria endemic areas by utilizing new diagnostic technology.
(2) Endemic situation of malaria, including prevalence of remote areas and spread of drug resistant malaria, is identified.
(3) Diagnostic techniques are developed and introduced to monitor the prevalence of NPDs.
(4) The effectiveness of innovative fluke inactivation techniques (for opisthorchiasis and schistosomiasis) is evaluated.
(5) Ecohealth education based on the results of research is introduced in model villages.

Financial support

This study is financially supported by Japan International Cooperation Agency (JICA) and Japan Agency for Medical Research and Development (AMED).

Scientific communications

Oral presentations:

1. Moritoshi Iwagami, Masami Nakatsu, Phonepadith Khattignavong, Sengdeuane Keomalaphet, Pheovaly Soundala, Paul Brey, Shigeyuki Kano, Human infection with simian malaria parasite: Current situation in Laos, Simian malaria as a zoonosis, Symposium, The 91st Annual Meeting of the Japanese Society of Parasitology, Obihiro, Japan, 28-29, May 2022 (Hybrid meeting)
2. Emilie Louise Akiko Matsumoto-Takahashi, Takashi Kumagai, Kei Oyoshi, Yoshinobu Sasaki, Shigeyuki Kano, Moritoshi Iwagami, Spatial epidemiology using earth observation satellite data for risk factor analysis of Schistosoma mekongi infection in Lao PDR, The 81st Annual Meeting of the Japanese Society of Parasitology Eastern Branch, Tokyo, Japan, 1-2, October 2022 (Hybrid meeting)
3. Emilie Matsumoto-Takahashi, Kei Oyoshi, Yoshinobu Sasaki, Moritoshi Iwagami, Shigeyuki Kano, Global warming and the distribution of malaria in Lao PDR: Analysis using earth observation satellite data, The 37th Congress of Japan Association for International Health, Aichi, Japan, 19-20, November 2022 (Hybrid meeting)

Poster presentation:

1. Moritoshi Iwagami, Masami Nakatsu, Phoyphaylinh Prasayasith, Sengdeuane Keomalaphet, Phonepadith Khattignavong, Pheovaly Soundala, Sonesimmaly Sannikone, Emilie Matsumoto‑Takahashi, Hiroyuki Ishikawa, Tiengkham Pongvongsa, Mayfong Mayxay, Paul Brey, Shigeyuki Kano, Double blind, parallel, randomized, placebo-controlled research to evaluate efficacy of 5-aminolevulinic acid with asymptomatic malaria parasite carriers in Laos, The 91st Annual Meeting of the Japanese Society of Parasitology, Obihiro, Japan, 28-29, May 2022 (Hybrid meeting)

Publication

Ken Ing Cherng Ong, Phonepadith Khattignavong, Sengdeuane Keomalaphet, Moritoshi Iwagami, Paul Brey, Shigeyuki Kano, Masamine Jimba, BMJ Open, Healthseeking behaviours in a malaria endemic district in Lao People’s Democratic Republic: a mixed methods study. 2021, 11(12): e055350.

Takashi Kumagai, Emilie Louise Akiko Matsumoto- Takahashi, Hirofumi Ishikawa, Sengdeuane Keomalaphet, Phonepadith Khattignavong, Pheovaly Soundala, Kei Oyoshi, Yoshinobu Sasaki, Yousei Mizukami, Shigeyuki Kano, Paul T. Brey, Moritoshi Iwagami, Pathogens, Detection of Schistosoma mekongi DNA in human stool and intermediate host snail, Neotricula aperta via loopmediated isothermal amplification assay in Lao PDR 2022 (accepted for publication).

In preparation

Emilie Louise Akiko Matsumoto-Takahashi, Takashi Kumagai, Kei Oyoshi, Yoshinobu Sasaki, Yousei Mizukami, Bouasy Hongvanthong, Paul T. Brey, Shigeyuki Kano, Moritoshi Iwagami, Impact of precipitation on the prevalence of schistosomiasis mekongi in Lao PDR: Structural equation modelling using Earth observation satellite data.

Somphou Sayasone, Phonepadith Khattignavong, Sengdeuane Keomalaphet, Phoyphaylinh Prasayasith, Pheovaly Soundala, Sonesimmaly Sannikone, Takashi Kumagai, Souk Phamhaksa, Phouth Inthavong, Bouasy Hongvanthong, Paul T. Brey, Shigeyuki Kano, Moritoshi Iwagami, Low prevalence of Schistosoma mekongi infection among domestic animals in southern Lao People’s Democratic Republic.

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