Behaviors Related to Mosquito-Borne Diseases among Different Ethnic Minority Groups along the China-Laos Border Areas

Metatranscriptomic Sequencing Reveals Host Species as an Important Factor Shaping the Mosquito Virome

Mosquitoes are important vector hosts for numerous viral pathogens and harbor a large number of mosquito-specific viruses as well as human-infecting viruses. Previous studies have mainly focused on the discovery of mosquito viruses, and our understanding of major ecological factors associated with virome structure in mosquitoes remains limited. We utilized metatranscriptomic sequencing to characterize the viromes of five mosquito species sampled across eight locations in Yunnan Province, China. This revealed the presence of 52 viral species, of which 19 were novel, belonging to 15 viral families/clades. Of particular note was Culex hepacivirus 1, clustering within the avian clade of hepaciviruses. Notably, both the viromic diversity and abundance of Aedes genus mosquitoes were significantly higher than those of the Culex genus, while Aedes albopictus mosquitoes harbored a higher diversity than Aedes aegypti mosquitoes. Our findings thus point to discernible differences in viromic structure between mosquito genera and even between mosquito species within the same genus. Importantly, such differences were not attributable to differences in sampling between geographical location. Our study also revealed the ubiquitous presence of the endosymbiont bacterium Wolbachia, with the genetic diversity and abundance also varying between mosquito species. In conclusion, our results suggested that the mosquito host species play an important role in shaping the virome's structure. IMPORTANCE This study revealed the huge capability of mosquitoes in harboring a rich diversity of RNA viruses, although relevant studies have characterized the intensively unparalleled diversity of RNA viruses previously. Furthermore, our findings showed discernible differences not only in viromic structure between mosquito genera and even between mosquito species within the same genus but also in the genetic diversity and abundance of Wolbachia between different mosquito populations. These findings emphasize the importance of host genetic background in shaping the virome composition of mosquitoes.

The Slums in the Mirror of Health: A Systematic Review Analysis from Iran

Background

One billion worldwide population is living in slum areas that mostly accompanied with high rates of poverty, illiteracy, unemployment, unhealthy situation, and inappropriate health-care services. The prediction of enormous growth of slums by 2030 led to a raise to address the "plight of slums" in Sustainable Development Goals (SDGs).

Methods

To address evidence-based health-related priorities, we conducted a systematic review to summarizing evidences on health situations of slums population in Iran. Six electronic databases were systematically searched for published studies without any restriction on age, sex, and language to assess health situations of slums in Iran reported by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. All identified articles were screened, quality assessed, and data extracted by two authors independently.

Results

The finding of this systematic review in addition to overall view categorized in five categories: health system, reproductive health, infectious diseases, noncommunicable diseases and their risk factors, social issues besides overall situation of Slums.

Conclusions

Community-based participatory interventions with socioeconomic approach on modifiable risk factors; active response of health system; establishment new health care centers in slum areas; augmenting the quality of care; active case finding; and elevating health knowledge, attitude, and practice is crucial to achieve SDG's in Slum area.

Rhinolophus sinicus virome revealed multiple novel mosquito-borne zoonotic viruses

To exploit the Rhinolophus sinicus–specific virome, 29 Rhinolophus sinicus were gathered in Lincang, China. Enriched viral sequences of 22 virus families were acquired by metavirome techniques. Hereby, the part of virome in Rhinolophus sinicus, including Chikungunya virus (CHIKV), Getah virus, and Japanese encephalitis virus (JEV) were validated by PCR. Five CHIKV viral sequences were amplified, among which CHIKV-China/B2016C-1 shared the highest homology to CHIKV isolated from Italy in 2007, with the genotype as African ECS. Eight JEV viral sequences were amplified, of which JEV-China/B2016E-1 shared the highest homology with at least 91.3% nt identity with the JEV sequence found in South Korea in 1988 and was classified as genotype III. Notably, JEV was isolated for the first time in Rhinolophus sinicus. The newly isolated JEV-China/B2016-1 could increase infectivity while passaging in Vero cells from BHK-21 cells. Overall, the research sheds insight into the diversity and viral susceptibility dynamics of the virome in Rhinolophus sinicus and reveals new light on the ecology of other important viral hosts.

Metavirome Analysis of Culex tritaeniorhynchus Reveals Novel Japanese Encephalitis Virus and Chikungunya Virus

To explore the Culex tritaeniorhynchuses–specific virome, 6400 C. tritaeniorhynchuses were collected in Honghe autonomous prefecture, China. Abundant virus sequences were obtained from 28 viral families using metavirome sequencing. Herein, several viruses in C. tritaeniorhynchuses virome were verified using the PCR technique, which covers Japanese encephalitis virus (JEV), Getah virus, and even Chikungunya virus (CHIKV). Seven JEV gene sequences were amplified successfully, of which JEV-China/CT2016E-1 shared the highest homology with the known JEV sequence isolated in Korea, 1946, with at least 96.1% nucleotide (nt) identity, which belonged to genotype III. Nine CHIKV gene sequences were amplified, which shared the highest with at least 93.0% nt identity with CHIKV from Thailand isolated in 2007, which was assigned to genotype Asian. Remarkably, CHIKV was isolated from C. tritaeniorhynchus in China for the first time. It was initially confirmed that the isolated virus CHIKV-China/CT2016-1 may increase infectivity after passaging in Vero cells from BHK-21 cells. Collectively, our study reveals the diversity, properties, and potential virus susceptibility dynamics of the C. tritaeniorhynchus virome and sheds new perspectives on the viral ecology in other important biological vectors.

OUP accepted manuscript

Although metagenomic sequencing has revealed high numbers of viruses in mosquitoes sampled globally, our understanding of how their diversity and abundance varies in time and space as well as by host species and gender remains unclear. To address this, we collected 23,109 mosquitoes over the course of 12 months from a bat-dwelling cave and a nearby village in Yunnan province, China. These samples were organized by mosquito species, mosquito gender, and sampling time for meta-transcriptomic sequencing. A total of 162 eukaryotic virus species were identified, of which 101 were novel, including representatives of seventeen RNA virus multi-family supergroups and four species of DNA virus from the families Parvoviridae, Circoviridae, and Nudiviridae. In addition, two known vector-borne viruses—Japanese encephalitis virus and Banna virus—were found. Analyses of the entire virome revealed strikingly different viral compositions and abundance levels in warmer compared to colder months, a strong host structure at the level of mosquito species, and no substantial differences between those viruses harbored by male and female mosquitoes. At the scale of individual viruses, some were found to be ubiquitous throughout the year and across four mosquito species, while most of the other viruses were season and/or host specific. Collectively, this study reveals the diversity, dynamics, and evolution of the mosquito virome at a single location and sheds new lights on the ecology of these important vector animals.

Knowledge and practice on prevention of mosquito-borne diseases in livestock-keeping and non-livestock-keeping communities in Hanoi city, Vietnam: A mixed-method study

Mosquito-borne diseases (MBDs) are causing high morbidity and mortality for humans. Urban livestock keeping is still common in cities around the world. The animals may serve as reservoirs for zoonotic MBDs, which increase the risks for humans. Here we assess the knowledge and practices related to MBDs in households with livestock and without livestock and explore the perceptions of the health care sector about MBDs and livestock keeping in Hanoi city of Vietnam in a cross-sectional study. A quantitative survey was conducted including 513 households with and without livestock-keeping in six districts and complemented with qualitative surveys with four health staff from Hanoi Center of Disease Control and three district health centers. The quantitative survey indicated that the participants possessed basic knowledge on MBDs with an average score of 18.3 out of 35, of which non-livestock-keeping households had a better knowledge than households keeping livestock (p<0.05). Both household categories had low score, 3.5 out of 11, regarding preventive practices against MBDs. The negative binomial model showed that occupation and location of living were factors associated to the knowledge on MBDs. Farmers were likely to have better preventive practices as compared to office workers (p<0.05). Those who had better knowledge also had more adequate preventive practices against MBDs (p<0.001). The qualitative survey revealed that livestock keeping was determined as increasing risks of MBDs due to the increase of mosquito population. It is recommended that community campaigns to raise the awareness and change behavior on MBDs should be organized based on collaboration between the health sector and the veterinary sector for households with and without livestock living in central urban and peri-urban areas. Further studies are needed to confirm the association between urban livestock keeping and potential increasing risks of MBDs such as dengue and Japanese encephalitis.

Temporal and spatial distribution of under-five mortality and factors associated with multiple cases of under-five deaths within a family in the rural area of Khuzestan, Southern Iran

Under-five mortality (U5M) is an important indicator of the overall health and development of society. There is a wide gap in U5M among different countries and also within the countries. This study was carried out to assess the prevalence, as well as the socio-demographic, and health-related causes of U5M in the region of study. A cross-sectional study was conducted among all registered cases of U5M in rural areas of Khuzestan province, Iran, during the years 2011 to 2015. To assess the socio-demographic determinants of U5M, the sample surveyed consists of 320 families with at least one under-five death using a multistage random sampling method. Also, this study evaluated the number of variables, which may increase the chance of families to have more than one U5M. U5M was 26 per 1000 live births in 2011, but decreased to 22 per 1000 live births in 2015. With the highest cumulative incidence of 43 in Masjed Soleyman and the lowest of 15 in Dehdez, infant mortality constitutes 76% of all U5M. Prematurity and congenital anomalies were responsible for 46% of all causes of mortality (that is, U5). Maternal age at delivery <18 years or >35 years (OR = 3.5; 95% CI, 1.29–6.22), marriage duration >9 years (1.85, 1.06–3.21), spouse age gap >5 years (2.32, 1.20–4.50), cesarean section (3.85, 1.19–5.74), delivery interval <3 years (2.83, 1.22–5.58), non-Arab ethnicity (2.58, 1.50–4.44), and mother working in agriculture or animal husbandry (3.93, 1.41–6.94) were the most important determinants associated with more than one child death per family. Spatially, there was a great disparity in U5M with different reduction rate during the 5 years of the study. Marriage age, cesarean delivery, delivery interval, and mother field activity were associated with U5M. This may have implications for the preventive health program.