Mosquitoes (Diptera: Culicidae) from Villages and Forest Areas of Rural Communes in Khanh Hoa and Binh Phuoc Provinces, Vietnam.

This study presents the diversity of mosquitoes collected from communes, endemic with malaria and dengue, located in Khanh Hoa and Binh Phuoc Provinces, Vietnam. A total of 10,288 mosquitoes were collected in the village and forested sites using standard larval dippers, cow-baited traps, ultra-violet light traps, and mechanical aspirators. Mosquito taxa were identified morphologically and species complexes/groups were further characterized molecularly. Five genera of mosquitoes were morphologically identified: Anopheles Meigen (21 species), Aedes Meigen (2 species), Culex Linnaeus (5 species), Mansonia Blanchard sp., and Armigeres Theobald sp. The PCR-based identification methods allowed the distinction of members of Maculatus Group, Funestus Group, and Dirus Complex; and DNA barcodes enabled the further identification of the Barbirostris Complex. Data reported here include the first report of An. saeungae Taai & Harbach and An. wejchoochotei Taai & Harbach from Vietnam, and re-emphasizes the significance of using molecular data in an integrated systematic approach to identify cryptic species and better understand their role in disease transmission.

Estimating and mitigating the risk of COVID-19 epidemic rebound associated with reopening of international borders in Vietnam: a modelling study.

BACKGROUND: Vietnam has emerged as one of the world's leading success stories in responding to COVID-19. After a prolonged period of little to no transmission, there was an outbreak of unknown source in July, 2020, in the Da Nang region, but the outbreak was quickly suppressed. We aimed to use epidemiological, behavioural, demographic, and policy data from the COVID-19 outbreak in Da Nang to calibrate an agent-based model of COVID-19 transmission for Vietnam, and to estimate the risk of future outbreaks associated with reopening of international borders in the country. METHODS: For this modelling study, we used comprehensive data from June 15 to Oct 15, 2020, on testing, COVID-19 cases, and quarantine breaches within an agent-based model of SARS-CoV-2 transmission to model a COVID-19 outbreak in Da Nang in July, 2020. We applied this model to quantify the risk of future outbreaks in Vietnam in the 3 months after the reopening of international borders, under different behavioural scenarios, policy responses (ie, closure of workplaces and schools), and ongoing testing. FINDINGS: We estimated that the outbreak in Da Nang between July and August, 2020, resulted in substantial community transmission, and that higher levels of symptomatic testing could have mitigated this transmission. We estimated that the outbreak peaked on Aug 2, 2020, with an estimated 1060 active infections (95% projection interval 890-1280). If the population of Vietnam remains highly compliant with mask-wearing policies, our projections indicate that the epidemic would remain under control even if a small but steady flow of imported infections escaped quarantine into the community. However, if complacency increases and testing rates are relatively low (10% of symptomatic individuals are tested), the epidemic could rebound again, resulting in an estimated 2100 infections (95% projected interval 1050-3610) in 3 months. These outcomes could be mitigated if the behaviour of the general population responds dynamically to increases in locally acquired cases that exceed specific thresholds, but only if testing of symptomatic individuals is also increased. INTERPRETATION: The successful response to COVID-19 in Vietnam could be improved even further with higher levels of symptomatic testing. If the previous approaches are used in response to new COVID-19 outbreaks, epidemic control is possible even in the presence of low levels of imported cases. FUNDING: Ministry of Science and Technology (Vietnam). TRANSLATION: For the Vietnamese translation of the abstract see Supplementary Materials section.

Evaluation of Vietnam's post-exposure prophylaxis delivery system, 2017.

BACKGROUND: Canine-mediated human rabies deaths typically occur in poor and rural populations with limited access to rabies biologics: vaccine and immunoglobulin. A critical aspect of reducing rabies deaths is understanding how these countries procure, deliver, and forecast rabies biologics. Vietnam is one of the few endemic countries where biologics is widely available. However, a formal evaluation of its current rabies biologics distribution system has not been conducted. METHODS: In 2017, we conducted a formal evaluation of Vietnam's rabies biologics distribution system. Our goals were (1) to identify centers providing rabies biologics (2) identify costs to the patient and centers and (3) assess the rabies biologic procurement and delivery system at eligible district and provincial centers (provides and orders biologics for itself and other centers directly from the manufacture). To conduct the formal evaluation, we developed a standardized survey that was distributed to centers. RESULTS: Of the 780 designated rabies biologics centers in Vietnam, 659 (84%) of them provide rabies immunoglobulin (eRIG), vaccine, or both. Of the 177 eligible centers, 90% (160) responded to the survey. The average costs to patients were $8.45 (range: 5.43-12.77) for one dose of IM injection, $13.90 (range: 11.86-16.71) for domestic eRIG, and $23 (21.11-27.11) for imported eRIG. Respondents reported experiencing delays in receiving vaccine in 50 centers and eRIG in 14 centers within the past year. Respondents stated their top three challenges in providing biologics were: delays or shortages from manufactures, lack of funds to pay for biologics, and the high cost of biologics. CONCLUSIONS AND RELEVANCE: Despite the wide availability of biologics in Vietnam, more work is needed to provide affordable and reliable supply of biologics to patients. This includes the expansion of ID injection use throughout the country to lower vaccine demand, and decrease the costs to centers and patients. Furthermore, a more coordinated effort to share biologics among centers, possibly through a more centralized system at the provincial level may alleviate delays and shortages.

Rabies Vaccine Hesitancy and Deaths Among Pregnant and Breastfeeding Women - Vietnam, 2015-2016.

Human rabies deaths are preventable through prompt administration of postexposure prophylaxis (PEP) with rabies immune globulin and rabies vaccine after exposure to a rabid animal (1); there are no known contraindications to receiving PEP (1,2). Despite widespread availability of PEP in Vietnam, in 2015 the Ministry of Health (MoH) received reports of pregnant and breastfeeding women with clinically diagnosed rabies. MoH investigated factors associated with these rabies cases. MoH found that, during 2015-2016, among 169 cases reported in Vietnam, two probable cases of rabies were reported in breastfeeding mothers and four in pregnant women, all of whom had been bitten by dogs. All six patients died. Three of the four pregnant women had cesarean deliveries. One of the three newborns died from complications believed to be unrelated to rabies; the fourth pregnant woman contracted rabies too early in pregnancy for the fetus to be viable. Two of the patients sought care from a medical provider or traditional healer; however, none sought PEP after being bitten. In each case, families reported the patient's fear of risk to the fetus or breastfed child as the primary barrier to receiving PEP. These findings highlight the need for public health messaging about the safety and effectiveness of PEP in preventing rabies among all persons with exposures, including pregnant and breastfeeding women.

National surveillance for influenza and influenza-like illness in Vietnam, 2006-2010.

Influenza virus infections result in considerable morbidity and mortality both in the temperate and tropical world. Influenza surveillance over multiple years is important to determine the impact and epidemiology of influenza and to develop a national vaccine policy, especially in countries developing influenza vaccine manufacturing capacity, such as Vietnam. We conducted surveillance of influenza and influenza-like illness in Vietnam through the National Influenza Surveillance System during 2006-2010. At 15 sentinel sites, the first two patients presenting each weekday with influenza-like illness (ILI), defined as fever and cough and/or sore throat with illness onset within 3 days, were enrolled and throat specimens were collected and tested for influenza virus type and influenza A subtype by RT-PCR. De-identified demographic and provider reported subsequent hospitalization information was collected on each patient. Each site also collected information on the total number of patients with influenza-like illness evaluated per week. Of 29,804 enrolled patients presenting with influenza-like illness, 6516 (22%) were influenza positive. Of enrolled patients, 2737 (9.3%) were reported as subsequently hospitalized; of the 2737, 527 (19%) were influenza positive. Across all age groups with ILI, school-aged children had the highest percent of influenza infection (29%) and the highest percent of subsequent hospitalizations associated with influenza infection (28%). Influenza viruses co-circulated throughout most years in Vietnam during 2006-2010 and often reached peak levels multiple times during a year, when >20% of tests were influenza positive. Influenza is an important cause of all influenza-like illness and provider reported subsequent hospitalization among outpatients in Vietnam, especially among school-aged children. These findings may have important implications for influenza vaccine policy in Vietnam.