Loop-Mediated Isothermal Amplification Assay to Detect Invasive Malaria Vector Anopheles stephensi Mosquitoes.

Spread of the Anopheles stephensi mosquito, an invasive malaria vector, threatens to put an additional 126 million persons per year in Africa at risk for malaria. To accelerate the early detection and rapid response to this mosquito species, confirming its presence and geographic extent is critical. However, existing molecular species assays require specialized laboratory equipment, interpretation, and sequencing confirmation. We developed and optimized a colorimetric rapid loop-mediated isothermal amplification assay for molecular An. stephensi species identification. The assay requires only a heat source and reagents and can be used with or without DNA extraction, resulting in positive color change in 30-35 minutes. We validated the assay against existing PCR techniques and found 100% specificity and analytical sensitivity down to 0.0003 nanograms of genomic DNA. The assay can successfully amplify single mosquito legs. Initial testing on samples from Marsabit, Kenya, illustrate its potential as an early vector detection and malaria mitigation tool.

Broadening the Environmental Lens to Include Social and Structural Determinants of Women's Health Disparities.

BACKGROUND: Due to the physical, metabolic, and hormonal changes before, during, and after pregnancy, women-defined here as people assigned female at birth-are particularly susceptible to environmental insults. Racism, a driving force of social determinants of health, exacerbates this susceptibility by affecting exposure to both chemical and nonchemical stressors to create women's health disparities. OBJECTIVES: To better understand and address social and structural determinants of women's health disparities, the National Institute of Environmental Health Sciences (NIEHS) hosted a workshop focused on the environmental impacts on women's health disparities and reproductive health in April 2022. This commentary summarizes foundational research and unique insights shared by workshop participants, who emphasized the need to broaden the definition of the environment to include upstream social and structural determinants of health. We also summarize current challenges and recommendations, as discussed by workshop participants, to address women's environmental and reproductive health disparities. DISCUSSION: The challenges related to women's health equity, as identified by workshop attendees, included developing research approaches to better capture the social and structural environment in both human and animal studies, integrating environmental health principles into clinical care, and implementing more inclusive publishing and funding approaches. Workshop participants discussed recommendations in each of these areas that encourage interdisciplinary collaboration among researchers, clinicians, funders, publishers, and community members. https://doi.org/10.1289/EHP12996.

Detection of Anopheles stephensi Mosquitoes by Molecular Surveillance, Kenya.

The Anopheles stephensi mosquito is an invasive malaria vector recently reported in Djibouti, Ethiopia, Sudan, Somalia, Nigeria, and Ghana. The World Health Organization has called on countries in Africa to increase surveillance efforts to detect and report this vector and institute appropriate and effective control mechanisms. In Kenya, the Division of National Malaria Program conducted entomological surveillance in counties at risk for An. stephensi mosquito invasion. In addition, the Kenya Medical Research Institute conducted molecular surveillance of all sampled Anopheles mosquitoes from other studies to identify An. stephensi mosquitoes. We report the detection and confirmation of An. stephensi mosquitoes in Marsabit and Turkana Counties by using endpoint PCR and morphological and sequence identification. We demonstrate the urgent need for intensified entomological surveillance in all areas at risk for An. stephensi mosquito invasion, to clarify its occurrence and distribution and develop tailored approaches to prevent further spread.

Microsporidia MB in the primary malaria vector Anopheles gambiae sensu stricto is avirulent and undergoes maternal and horizontal transmission.

BACKGROUND: The demonstration that the recently discovered Anopheles symbiont Microsporidia MB blocks malaria transmission in Anopheles arabiensis and undergoes vertical and horizontal transmission suggests that it is a promising candidate for the development of a symbiont-based malaria transmission-blocking strategy. The infection prevalence and characteristics of Microsporidia MB in Anopheles gambiae sensu stricto (s.s.), another primary vector species of malaria in Kenya, were investigated. METHODS: Field-collected females were confirmed to be Microsporidia MB-positive after oviposition. Egg counts of Microsporidia MB-infected and non-infected individuals were used to infer the effects of Microsporidia MB on fecundity. The time to pupation, adult sex ratio and survival were used to determine if Microsporidia MB infection has similar characteristics in the host mosquitoes An. gambiae and An. arabiensis. The intensity of Microsporidia MB infection in tissues of the midgut and gonads, and in carcasses, was determined by quantitative polymerase chain reaction. To investigate horizontal transmission, virgin males and females that were either Microsporidia MB-infected or non-infected were placed in standard cages for 48 h and allowed to mate; transmission was confirmed by quantitative polymerase chain reaction targeting Microsporidia MB genes. RESULTS: Microsporidia MB was found to naturally occur at a low prevalence in An. gambiae s.s. collected in western Kenya. Microsporidia MB shortened the development time from larva to pupa, but other fitness parameters such as fecundity, sex ratio, and adult survival did not differ between Microsporidia MB-infected and non-infected hosts. Microsporidia MB intensities were high in the male gonadal tissues. Transmission experiments indicated that Microsporidia MB undergoes both maternal and horizontal transmission in An. gambiae s.s. CONCLUSIONS: The findings that Microsporidia MB naturally infects, undergoes maternal and horizontal transmission, and is avirulent in An. gambiae s.s. indicate that many of the characteristics of its infection in An. arabiensis hold true for the former. The results of the present study indicate that Microsporidia MB could be developed as a tool for the transmission-blocking of malaria across different Anopheles species.

Perception Toward Exposure Risk of COVID-19 Among Health Workers in Vietnam: Status and Correlated Factors.

Background: Hospital staff are at the frontline for the prevention and control of COVID-19. Understanding their perception of exposure risk is, therefore, important during the early phase of this pandemic. In this study, we evaluated the perception regarding risk of exposure to COVID-19 among Vietnamese hospital staff in Vietnam. Method: A cross-sectional online study was carried out to collect demographic data and risk exposure perception during the second week of the national lockdown in April 2020 in Vietnam. Seven hundred and forty two hospital staff were recruited using the snowball sampling to answer 5-point Likert scale questions regarding their risk exposure perception. Exploratory factor analysis (EFA) was used to examine the construct validity of the questionnaire. Pearson coefficient analysis and multivariable regression models were applied to identify factors associated with the perceived COVID-19 exposure risk. Results: Participants perceived a high risk of being infected with SARS-CoV-2 (score = 3.4, SD = 0.8). They also perceived the workplace response to COVID-19 as inadequate (score = 2.0, SD = 0.5). In particular, participants who worked in the emergency or intensive care departments were more likely to perceive an exposure risk, compared to those in infectious disease control departments (Coef. = -0.38, 95%CI: -0.74; -0.02). Participants from central regions perceived a lower risk of exposure to COVID-19 than those from northern regions (OR = 0.52, 95%CI: 0.28-0.96). Nurses were less likely than doctors to report being at risk of exposure to COVID-19 (OR = 0.56, 95%CI: 0.33-0.95). Conclusions: We identified a high level of perceived risk regarding COVID-19 exposure among hospital staff during the unprecedented lockdown period in Vietnam. A comprehensive approach, incorporating improved risk communications, safety training and psychological support programs, for all hospital staff, including nurses and those residing in high population density areas, might further strengthen the national effort to control the pandemic.

Susceptibility and perceptions of excessive internet use impact on health among Vietnamese youths.

Studies performed worldwide show excessive Internet use could have a negative impact on health. However, Internet use studies in Vietnam are limited. In this study, we reported a high prevalence of frequent Internet usage among Vietnamese youth between 16 and 30 years old. Of 1200 participants, almost 65% reported using the Internet daily. Moreover, 34.3% of the participants reported feeling anxious or uncomfortable after not using the Internet for one day irrespective of their gender, and 40% believed using the Internet frequently did not affect their health. Of those, there was a higher proportion of women than men that held this belief (42.1% vs. 35.9%, respectively, p = .03). In this cohort, undergraduate students were more likely than blue-collar workers to believe that frequent Internet use could affect health. Yet, undergraduate [OR = 1.50, 95%CI = (1.08, 2.09), p < .05)] and high school students (OR = 1.54, 95%CI = 1.00, 2.37), p < .1) were more likely than blue collar workers to feel anxious or uncomfortable after a day without the Internet. Participants in urban areas were more than twice as likely than those from rural areas to believe the Internet did not affect their health [(OR = 0.60, 95%CI = (0.41,0.89), p < .01)]. Lastly, participants between 16 and 18 years old were less likely to believe in the negative impact of the Internet on health than older participants. A better understanding of factors underlying high Internet usage and low perception of its health effects among Vietnamese youth might help develop better intervention strategies for Internet Use Disorder and other Technology Related Use Disorders.