Probable contribution of Culex quinquefasciatus mosquitoes to the circulation of chikungunya virus during an outbreak in Mombasa County, Kenya, 2017-2018

High Frequencies of kdr Mutation and Chikungunya Infection in Aedes aegypti Population from Minas Gerais, Brazil

The Chikungunya virus (CHIKV) presents global health challenges, with Brazil experiencing outbreaks since its introduction in 2014. In 2023, following a CHIKV outbreak in Minas Gerais (MG), social media was used to optimize an entomological survey aimed at identifying vectors and viral lineages and assessing insecticide resistance. Following Instagram posts, residents with suspected CHIKV infection were able to schedule mosquito aspirations. In total, 421 mosquitoes (165 Aedes aegypti and 256 Culex quinquefasciatus) were captured from 40 households in Salinas city (MG) and tested for the Dengue, Zika, and Chikungunya viruses through RT-qPCR. Twelve of 57 pools (10 Ae. aegypti and two Cx. quinquefasciatus) tested positive for CHIKV RNA. Viral RNA was also detected in the heads of nine Ae. aegypti, indicating viral dissemination but not in Cx. quinquefasciatus. Genome sequencing yielded the first near-complete genome from the 2023 outbreak, unveiling that the CHIKV strain belonged to the East/Central/South African (ECSA) genotype. Additionally, genetic analyses revealed high frequencies of kdr alleles, including in CHIKV-infected mosquitoes, suggesting resistance to pyrethroid insecticides in this Ae. aegypti population. Social media was important for guiding mosquito-capture efforts in CHIKV transmission hotspots, thus optimizing the opportunity for viral detection. These findings emphasize the urgent need for innovative vector studies and control strategies, as well as interdisciplinary approaches in public health interventions.

Growth in chikungunya virus-related research in ASEAN and South Asian countries from 1967 to 2022 following disease emergence: a bibliometric and graphical analysis

BACKGROUND

ASEAN (Association of Southeast Asian Nations) is composed of ten Southeast Asian countries bound by socio-cultural ties that promote regional peace and stability. South Asia, located in the southern subregion of Asia, includes nine countries sharing similarities in geographical and ethno-cultural factors. Chikungunya is one of the most significant problems in Southeast and South Asian countries. Much of the current chikungunya epidemic in Southeast Asia is caused by the emergence of a virus strain that originated in Africa and spread to Southeast Asia. Meanwhile, in South Asia, three confirmed lineages are in circulation. Given the positive correlation between research activity and the improvement of the clinical framework of biomedical research, this article aimed to examine the growth of chikungunya virus-related research in ASEAN and South Asian countries.

METHODS

The Scopus database was used for this bibliometric analysis. The retrieved publications were subjected to a number of analyses, including those for the most prolific countries, journals, authors, institutions, and articles. Co-occurrence mapping of terms and keywords was used to determine the current state, emerging topics, and future prospects of chikungunya virus-related research. Bibliometrix and VOSviewer were used to analyze the data and visualize the collaboration network mapping.

RESULTS

The Scopus search engine identified 1280 chikungunya-related documents published by ASEAN and South Asian countries between 1967 and 2022. According to our findings, India was the most productive country in South Asia, and Thailand was the most productive country in Southeast Asia. In the early stages of the study, researchers investigated the vectors and outbreaks of the chikungunya virus. In recent years, the development of antivirus agents has emerged as a prominent topic.

CONCLUSIONS

Our study is the first to present the growth of chikungunya virus-related research in ASEAN and South Asian countries from 1967 to 2022. In this study, the evaluation of the comprehensive profile of research on chikungunya can serve as a guide for future studies. In addition, a bibliometric analysis may serve as a resource for healthcare policymakers.

Urbanization of Aedes mosquito populations and evolution of arboviral disease risk in Africa

The arboviral diseases dengue, chikungunya, and yellow fever are re-merging and gaining a foothold in Africa, with a significant threat of large outbreaks in urban areas. Although their emergence is intimately linked to the primary vector Aedes aegypti, which thrives in urban environments, the risk of these diseases remains substantially heterogeneous in different geographic areas. Range expansion of invasive mosquito species Aedes albopictus, and colonization of urban habitats by sylvatic and peridomestic Aedes vectors, are likely to alter the diseases' epidemiology. We discuss how a network of different vector species and perhaps vector subpopulations could interact with associated serotypes/genotypes/lineages of the causative viruses of these diseases potentially impacting transmission risk in urban landscapes with implications for disease surveillance and control.

Potential Nosocomial Infections by the Zika and Chikungunya Viruses in Public Health Facilities in the Metropolitan Area of Recife, Brazil

Since 2015, the Dengue, Zika, and Chikungunya viruses gained notoriety for their impact in public health in many parts of the globe, including Brazil. In Recife, the capital of Pernambuco State, the introduction of ZIKV impacted human population tremendously, owing to the increase in the number of neurological cases, such as the Guillain−Barré and congenital Zika disorders. Later, Recife was considered to be the epicenter for ZIKV epidemics in Brazil. For arboviral diseases, there are some risk factors, such as climate changes, low socioeconomic conditions, and the high densities of vectors populations, that favor the broad and rapid dispersion of these three viruses in the city. Therefore, continuous arbovirus surveillance provides an important tool for detecting these arboviruses and predicting new outbreaks. The purpose of the present study was to evaluate the circulation of DENV, ZIKV, and CHIKV by RT-qPCR in mosquitoes collected in health care units from the metropolitan area of Recife (MAR), during 2018. A total of 2321 female mosquitoes (357 pools) belonging to two species, Aedes aegypti and Culex quinquefasciatus, were collected from 18 different healthcare units, distributed in five cities from the MAR. Twenty-three pools were positive for ZIKV, out of which, seventeen were of C. quinquefasciatus and six were of A. aegypti. Positive pools were collected in 11/18 health care units screened, with Cq values ranging from 30.0 to 37.4 and viral loads varying from 1.88 × 107 to 2.14 × 109 RNA copies/mL. Nosocomial Aedes- and Culex-borne transmission of arbovirus are widely ignored by surveillance and vector control programs, even though healthcare-associated infections (HAI) are considered a serious threat to patient safety worldwide. Although the results presented here concern only the epidemiological scenario from 2018 in MAR, the potential of hospital-acquired transmission through mosquito bites is being overlooked by public health authorities. It is, therefore, of the ultimate importance to establish specific control programs for these locations.

Spread of a Novel Indian Ocean Lineage Carrying E1-K211E/E2-V264A of Chikungunya Virus East/Central/South African Genotype across the Indian Subcontinent, Southeast Asia, and Eastern Africa

The Indian Ocean Lineage (IOL) of the chikungunya virus (CHIKV) East/Central/South African (ECSA) genotype, which originated in Kenya, spread to the Indian ocean and the Indian subcontinent, and then expanded through Southeast Asia in the previous decade. It carried an adaptive mutation E1-A226V, which enhances CHIKV replication in Aedes albopictus. However, the IOL CHIKV of the most recent outbreaks during 2016-2020 in India, Pakistan, Bangladesh, the Maldives, Myanmar, Thailand, and Kenya lacked E1-A226V but carried E1-K211E and E2-V264A. Recent CHIKV genome sequences of the Maldives and Thailand were determined, and their phylogenetic relationships were further investigated together with IOL sequences reported in 2004-2020 in the database. The results showed that the ancestral IOLs diverged to a sub-lineage E1-K211E/E2-V264A, probably in India around 2008, and caused sporadic outbreaks in India during 2010-2015 and in Kenya in 2016. The massive expansion of this new sub-lineage occurred after the acquisition of E1-I317V in other neighboring and remote regions in 2014-2020. Additionally, the phylogenetic tree indicated that independent clades formed according to the geographical regions and introduction timing. The present results using all available partial or full sequences of the recent CHIKVs emphasized the dynamics of the IOL sub-lineages in the Indian subcontinent, Southeast Asia, and Eastern Africa.