Volume 25, Number 11—November 2019
21st International Conference on Emerging Infectious Diseases in the Pacific Rim
The U.S.–Japan Cooperative Medical Sciences Program (USJCMSP) was established in 1965 by Prime Minister Eisaku Sato of Japan and President Lyndon B. Johnson of the United States to strengthen Japan’s research capacity and address public health concerns in the Asia-Pacific region (https://www.amed.go.jp/en/program/list/03/01/007.html). USJCMSP currently has 9 joint panels of scientific experts overseeing research in acute respiratory infections; AIDS; cholera and other bacterial enteric infections; hepatitis; nutrition and metabolism; cancer; parasitic diseases; mycobacterial diseases; and viral diseases, as well as a cross-cutting immunology board.
In 1996, USJCMSP pioneered the International Conference on Emerging Infectious Diseases of the Pacific Rim. The conferences, held in countries in the Asia-Pacific region (Table), provide a venue for panel meetings, discussions on infectious disease research, and opportunities for collaboration.
The 21st conference, hosted by the Ministry of Health of Vietnam and held in Hanoi during February 26–March 1, 2019, focused on bacterial and parasitic diseases. The conference program included 5 plenary sessions: One Health; genomics; antimicrobial resistance (AMR); technologies and heterogeneity/single cell; and the microbiome, immunity, and cancer. The conference program and other materials are available on the conference website (http://www.cvent.com/events/u-s-japan-cooperative-medical-sciences-program-usjcmsp-21st-international-conference-on-emerging-inf/event-summary-a5489b8e72fb476ca8ff229650f812e3.aspx).
One Health takes a holistic view of hosts, vectors, zoonotic reservoirs, and the ecosystem to study emerging diseases and disease transmission. In the Asia-Pacific region, viruses that cause human illnesses, such as influenza and Nipah virus, harbor in birds or bats, move into zoonotic reservoirs, and adapt and mutate in intermediate hosts before infecting humans. Presenters at this year’s conference described an initiative in Bhutan that created a One Health South Asian network, extending to Afghanistan, Nepal, and Bangladesh. The initiative enables training in epidemiology, animal health, molecular methods, and economic analyses applicable to tracking brucellosis, rabies, Q fever, toxoplasmosis, Japanese encephalitis virus, and avian influenza. Other One Health topics included tuberculosis transmission from humans to elephants in Nepal; deer, rhinoceroses, and blue bulls transmitting Mycobacterium orygis; Rhesus monkeys dying of tuberculosis in Bangladesh; genetically distinct Bacillus anthracis in humans in Vietnam; and antimicrobial-resistant strains of Listeria monocytogenes isolated from carrots, eggplants, and other crops in Malaysia.
The session on genomics covered its application to investigate genetic diversity, epidemiologic complexity, pandemic outbreaks, pathogen resistance, and host–pathogen interactions in the context of malaria, tuberculosis, and cholera. Plasmodium vivax accounts for >80% of the global burden of malaria in the Asia-Pacific region. Presenters described how P. vivax in Papua New Guinea exhibits greater genetic diversity and epidemiologic complexity and resistance to control than P. falciparum. Other presenters discussed genomic analysis of P. simium, which caused an outbreak of human malaria in the Atlantic Forest of Rio de Janeiro. They found P. simium from the outbreak has a close genetic and morphological resemblance to P. vivax, and their phylogenetic analysis juxtaposed the 2 species. Their analysis suggests that P. vivax originated in great apes in Africa before infecting humans and that after 1492, human hosts transported P. vivax to South America, where it adapted to New World monkeys and further evolved into infectious P. simium.
Another genomic study explored the current >50-year cholera pandemic, the cause of which is a limited number of closely-related clades of Vibrio cholera. Genomic evidence points to the pathogen’s evolution in dense human populations of the Ganges Delta, with seeding introductions of cholera to other countries and continents.
The session on AMR focused on drug resistance in different community settings, microbial mechanisms to mediate AMR, and coordinated actions to minimize the emergence and spread of AMR. Presenters described infection control measures in hospitals in Vietnam, notably for carbapenem-resistant Enterobacteriaceae (CRE), which show strong correlations between CRE colonization, hospital-acquired infections, duration of treatment, and fatality.
In Japan, prevalent AMR infections include enterohemorrhagic Escherichia coli (EHEC) and healthcare-associated infections, such as CRE, multidrug resistant Acinetobacter sp., and vancomycin-resistant Enterobacteriace. Presenters described the use of multiple-locus variable number tandem repeat analysis to detect diffuse outbreaks and prevent disease transmission by identifying an identical genotype of EHEC.
In the Greater Mekong Subregion, artemisinin-resistant malaria is widespread and associated with evolving polymorphisms in the P. falciparum Kelch propeller K13 gene. P. vivax is the predominant parasite and a presenter described how resistance to chloroquine might involve novel mutations in the Pvmdr1 gene. Another AMR presentation described the continuing challenges of cholera in Kenya, where V. cholera demonstrates resistance against β-lactam and disease hotspots are expanding to refugee camps despite improvements in sanitation.
The technologies and heterogeneity/single cell session explored recent technological advances in tracking disease progression, evaluating organisms responsible for human infectious diseases, and characterizing stages of disease manifestations. A talk on Helicobacter pylori covered how it colonizes and limits repair at gastric damage sites via chemotactic motility. The presenters are investigating mutations in chemokine receptors, which could help define the role of chemotaxis in H. pylori pathogenesis. Another presentation discussed RNA interference as a promising tool against mosquitoes and for mosquitoborne disease control. A third presenter described the use of CRISPR-based functional genomics for identifying new drug targets for tuberculosis and how progression of Mycobacterium tuberculosis infections can be tracked by combining positron emission tomography and computed tomography with immunology and microbiology in in vivo models. A final presenter discussed the use of whole genome sequencing to reconstruct the migration and expansion of human infectious diseases by using phylogenetic reconstruction of Schistosomiasis japonica to demonstrate its evolution through rice planting, agricultural development, human movement, and population increases.
The session on the microbiome, immunity, and cancer included a metabologenomic study demonstrating that lactate derived from dietary fiber fermentation by lactic acid bacteria accelerates colonic epithelial cell turnover and development of aberrant crypt foci after carcinogen treatment. Another speaker described how the gut ecosystem, formed by microbiota, has a profound influence on human physiology, immunology, and nutrition, and imbalance in its structure could increase risk for colorectal cancers. In a human study described during this session, the fecal microbiome and its metabolite profile shifted from early stage polyps to colorectal carcinoma, and researchers found specific fecal microbes and metabolites correlated with the stage of colorectal carcinoma. The research suggests gut microbiota–derived metabolites could factor into our understanding of tumorigenesis and provide information for early detection and prevention strategies. Another speaker’s research found that tuberculosis exposure is associated with microbiome changes in patients in Haiti and induction of an early innate immune response.
Suggested citation for this article: Rao M, Hall R, Lu K, Mason R, Bernabe G, Brennan P, et al. 21st International Conference on Emerging Infectious Diseases in the Pacific Rim. Emerg Infect Dis. 2019 Nov [date cited]. https://doi.org/10.3201/eid2511.191184
Original Publication Date: September 27, 2019