Infectious and Tropical diseases

Vietnam faces infectious diseases, tropical diseases related to the climate characteristics of the region. Research in these areas is also interested by the ICHR Institute with many quality studies and projects. Below are abstracts of the ICHR Institute's recent studies, with the names in bold being the members of the ICHR Institute.The full text can be found in the Institute's International publications directory.

1. Mass masking as a way to contain COVID-19 and exit lockdown in low- and middle-income countries

Joseph Nelson Siewe Fodjo, Supa Pengpid, Edlaine Faria de Moura Villela, Vo Van Thang, Mohammed Ahmed, John Ditekemena, Bernardo Vega Crespo, Rhoda K Wanyenze, Janeth Dula, Takashi Watanabe, Christopher Delgado-Ratto, Koen Vanden Driessche, Rafael Van den Bergh, Robert Colebunders

In new guidelines published on June 5th 2020, the World Health Organization (WHO) recommends that in areas with ongoing COVID-19 community transmission, governments should encourage the general public to wear face masks in specific situations and settings as part of a comprehensive approach to suppress COVID-19 transmission. Recent online surveys in 206,729 persons residing in nine low- and middle-income countries showed that 32.7%-99.7% of respondents used face masks with significant differences across age groups and sexes. Targeted health promotion strategies and government support are required to increase mask use by the general population.

2. Incidence of snakebites in Can Tho Municipality, Mekong Delta, South Vietnam— Evaluation of the responsible snake species and treatment of snakebite envenoming

Vo Van Thang, Truong Quy Quoc Bao, Hoang Dinh Tuyen, Ralf Krumkamp, Le Hoang Hai, Nguyen Hai Dang, Cao Minh Chu, Joerg Blessmann

Background Data on incidence of snakebites and the responsible snake species are largely missing in Vietnam and comprehensive national guidelines for management of snakebite envenoming are not yet available. They are needed to estimate the scope of this health problem, to assess the demand for snake antivenom and to ensure the best possible treatment for snakebite victims. Methodology/Principle findings A cross-sectional community-based survey was conducted from January to April 2018. Multistage cluster sampling was applied and snakebite incidence in Can Tho municipality, excluding two central districts of Can Tho city, was calculated at 48 (95%-confidence interval (CI): 20.5–99.8) snakebites per 100,000 person-years. Seven snakebite victims found during the survey reported 3 bites from green pit vipers and 4 bites from non-venomous snakes. In 2017 two treatment centres for snakebite envenoming in Can Tho city, the Military Hospital 121 and the Paediatric Hospital, received 520 admissions of snakebite victims. Two hundred sixty-seven came from Can Tho Municipality and 253 from neighbouring provinces. According to these data, the incidence of snakebites for Can Tho municipality was calculated at 21 (95%-CI: 18.5–23.7) snakebites per 100,000 person-years. Incidence was 14 (95%-CI: 12–17) snakebites per 100,000 person years in those 7 districts of the municipality which were part of the community survey. Green pit vipers were responsible for 92% of snakebite envenoming. Antivenom, antibiotics and corticosteroids were administered to 405 (90%), 379 (84%), and 310 (69%) out of 450 patients, respectively. Conclusions Incidence of snakebites in Can Tho Municipality is relatively low and green pit vipers are responsible for the vast majority of bites. Approximately one third of snakebite patients sought medical care in hospitals and although hospital data still underestimate the real incidence of snakebites, these statistics are valuable and can be obtained fast and inexpensively. Evaluation of patients’ records indicates the need for development of guidelines for management of snakebite envenoming in Vietnam to ensure a rational use of antivenom and ancillary treatments.

Dr. Joerg Blessmann - from Bernhard Nocht Institute for Tropical Medicine, Germany on his project "Epidemiology and Management of snakebites in Thua Thien Hué Province, Vietnam" with strongly support from ICHR.

3. Incidence of snakebites and medically relevant snakes in different regions in Laos and Vietnam

Joerg Blessmann; Inthanomchanh Vongphoumy; Nguyen Thanh Phuc Nhan; Bui Thi Phuong Anh; Nguyen Hoang Lan; Truong Quy Quoc Bao; Sulaphab Hanlodsomphou; Khamla Choumlivong; Phet Soukhaphouvong; Vo Van Thang

Objective: The objective of the community-based surveys was to estimate the incidence of snakebites in Savannakhet province, in southern Laos, Thua Thien Hue province, in central Vietnam and Can Tho Municipality in the Mekong Delta in South Vietnam. Evaluation of hospital records of snakebite patients in the same regions provided information about medically relevant snakes.

Methods: Cross-sectional, community-based surveys were performed in Savannakhet province in Lao PDR, and in Thua Thien Hue Province and Can Tho Municipality in Vietnam. Multi-stage random sampling was used to select interviewees in the villages.

Results: Incidence of snakebites is high in Savannakhet province in southern Laos with up to 1105 snakebites per 100,000 persons per year. Malayan pit vipers, green pit vipers, Indochinese cobras and Malayan kraits were responsible for 40%, 30%, 25% and 5% of snakebites respectively. In Thua Thien Hue province in central Vietnam and Can Tho municipality in South Vietnam incidence was calculated at 58 and 48 snakebites per 100,000 persons per year respectively. Green pit vipers and cobras caused the majority of snakebites in both regions.

Conclusion: Incidence of snakebites is significantly lower in central and southwest Vietnam compared to Savannakhet province in Lao PDR. Advanced mechanization in agriculture, a lower poverty rate, a different snake fauna and the exploitation of snakes for food, snake wine and traditional healing practices are main reasons for the lower incidence in the two provinces in Vietnam. Furthermore, increasing urbanization and cultivation of land for commercial purpose in this densely populated country most likely deprive snakes of their habitat.

4. Incidence of snakebites in 3 different geographic regions in Thua Thien Hue province, central Vietnam: Green pit vipers and cobras cause the majority of bites

Joerg Blessmann, Nguyen Thanh Phuc Nhan, Bui Thi Phuong Anh, Ralf Krumkamp, Vo Van Thang, Nguyen Hoang Lan

Background: The annual incidence of snakebites in Vietnam is not known and only few publications about snakebite envenoming and medically relevant snakes can be found in English language literature. The present community-based surveys provide data on incidence of snakebites in three different geographic regions of Thua Thien Hue (TT Hue) province, central Vietnam and snake species responsible for bites in this region.

Methodology/results: The cross-sectional community based surveys were conducted from March to July 2017. Multistage cluster sampling was applied and snakebite incidence was calculated at 58 snakebites per 100,000 person-years for the entire province, and 172, 69 and 10 snakebites per 100,000 person-years in the mountainous, coastal and urban region of TT Hue province, respectively. Thirty-one snakebite victims interviewed during the surveys reported 18 (58%) green pit viper bites (Trimeresurus species), 5 (16%) cobra bites (Naja kaouthia, Naja siamensis), 2 (7%) krait bites (Bungarus candidus, Bungarus fasciatus), 2 (7%) red-necked keelback bites (Rhabdophis subminiatus) and 4 bites from unidentified snakes (13%). The outcome was favourable for 28 snakebite victims (90%), two (6%) had minor sequelae and one (3%) victim died after a Malayan krait bite. Two hundred and twenty-one snakebite patients were treated in 9 district hospitals and one central hospital in TT Hue between 2014 and 2016. Eighty green pit vipers (84%), 12 cobras (13%) and 3 kraits (3%) were responsible for bites in 95 patients where snake identification was documented.

Conclusions: Incidence of snakebites is surprisingly low in TT Hue province in central Vietnam in comparison to other regions in Asia, particularly to neighbouring Lao PDR. However, snakebites are still a significant health problem in the mountainous region and green pit vipers and cobras cause the vast majority of bites.

In this project, ICHR staff and Dr. Joerg Blessmann have designed leaflets (brochure) to distribute to people on how to recognize and provide first aid for common venomous snake bites.

5. Social contexts of risk behaviors for HIV among male, unskilled, unregistered laborers in urban Vietnam

V. H. Nguyen, M. P. Dunne, J. Debattista, T. H. Nguyen, T. M. Dao

In Vietnam there has been relatively little success in controlling the HIV epidemic, in part because the subpopulations most exposed to the virus are often difficult to engage in prevention research and programs. In this qualitative study we explored social contexts shaping HIV risk behaviors among Vietnamese men involved in unskilled, unregistered, and low-income labor in urban settings. Based on self-disclosed behaviors, it is clear that these men were at high risk of sexually transmitted infection (STI). Evidence emerged from the interview data highlighting equivalent influences of individual psychological factors, social integration, social barriers, and accessibility regarding drug use and sexual risk behavior. Psychological influences such as tedium, distress, fatalism and revenge, and the strong effects of collective decision making and fear of social isolation appeared important for these men living on the economic and social margins of this rapidly urbanizing society. The study findings suggest directions for research and culturally appropriate HIV preventive education and services for these men.