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Scientific Data Jun 2024Aedes aegypti is a primary vector for transmitting various arboviruses, including Yellow fever, dengue and Zika virus. The mosquito midgut is the principal organ for...
Aedes aegypti is a primary vector for transmitting various arboviruses, including Yellow fever, dengue and Zika virus. The mosquito midgut is the principal organ for blood meal digestion, nutrient absorption and the initial site of arbovirus infection. Although a previous study delineated midgut's transcriptome of Ae. aegypti at the single-nucleus resolution, there still lacks an established protocol for isolating and RNA sequencing of single cells of Ae. aegypti midgut, which is required for investigating arbovirus-midgut interaction at the single-cell level. Here, we established an atlas of the midgut cells for Ae. aegypti by single-cell RNA sequencing. We annotated the cell clusters including intestinal stem cells/enteroblasts (ISC/EB), cardia cells (Cardia), enterocytes (EC, EC-like), enteroendocrine cells (EE), visceral muscle (VM), fat body cells (FBC) and hemocyte cells (HC). This study will provide a foundation for further studies of arbovirus infection in mosquito midgut at the single-cell level.
Topics: Animals; Aedes; Single-Cell Analysis; Female; Sequence Analysis, RNA; Transcriptome; Gastrointestinal Tract; Mosquito Vectors; Digestive System
PubMed: 38839790
DOI: 10.1038/s41597-024-03432-8 -
PLoS Neglected Tropical Diseases Jun 2024Dengue, Zika, and chikungunya, whose viruses are transmitted mainly by Aedes aegypti, significantly impact human health worldwide. Despite the recent development of...
BACKGROUND
Dengue, Zika, and chikungunya, whose viruses are transmitted mainly by Aedes aegypti, significantly impact human health worldwide. Despite the recent development of promising vaccines against the dengue virus, controlling these arbovirus diseases still depends on mosquito surveillance and control. Nonetheless, several studies have shown that these measures are not sufficiently effective or ineffective. Identifying higher-risk areas in a municipality and directing control efforts towards them could improve it. One tool for this is the premise condition index (PCI); however, its measure requires visiting all buildings. We propose a novel approach capable of predicting the PCI based on facade street-level images, which we call PCINet.
METHODOLOGY
Our study was conducted in Campinas, a one million-inhabitant city in São Paulo, Brazil. We surveyed 200 blocks, visited their buildings, and measured the three traditional PCI components (building and backyard conditions and shading), the facade conditions (taking pictures of them), and other characteristics. We trained a deep neural network with the pictures taken, creating a computational model that can predict buildings' conditions based on the view of their facades. We evaluated PCINet in a scenario emulating a real large-scale situation, where the model could be deployed to automatically monitor four regions of Campinas to identify risk areas.
PRINCIPAL FINDINGS
PCINet produced reasonable results in differentiating the facade condition into three levels, and it is a scalable strategy to triage large areas. The entire process can be automated through data collection from facade data sources and inferences through PCINet. The facade conditions correlated highly with the building and backyard conditions and reasonably well with shading and backyard conditions. The use of street-level images and PCINet could help to optimize Ae. aegypti surveillance and control, reducing the number of in-person visits necessary to identify buildings, blocks, and neighborhoods at higher risk from mosquito and arbovirus diseases.
Topics: Aedes; Animals; Brazil; Humans; Mosquito Vectors; Dengue; Cities; Mosquito Control; Image Processing, Computer-Assisted; Zika Virus Infection
PubMed: 38829905
DOI: 10.1371/journal.pntd.0011811 -
The Pan African Medical Journal 2024Aedes albopictus, like Aedes aegypti, is a virulent vector of arboviruses especially the well-documented spread of yellow fever around the world. Although yellow fever...
INTRODUCTION
Aedes albopictus, like Aedes aegypti, is a virulent vector of arboviruses especially the well-documented spread of yellow fever around the world. Although yellow fever is prevalent in Nigeria, there is a paucity of information in the Niger Delta region on the distribution of Aedes mosquito vectors and molecular detection of the virus in infected mosquitoes. This study sampled Aedes mosquitoes around houses associated with farms from four communities (Otolokpo, Ute-Okpu, Umunede, and Ute Alohen) in Ika North-East Local Government Area of Delta State, Nigeria.
METHODS
various sampling methods were used in Aedes mosquito collection to test their efficacy in the survey. Mosquitoes in holding cages were killed by freezing and morphologically identified. A pool of 15 mosquitoes per Eppendorf tube was preserved in RNAi later for yellow fever virus screening. Two samples were molecularly screened for each location.
RESULTS
seven hundred and twenty-five (725) mosquitoes were obtained from the various traps. The mean abundance of the mosquitoes was highest in m-HLC (42.9) compared to the mosquitoes sampled using other techniques (p<0.0001). The mean abundance of mosquitoes was lowest in Center for Disease Control (CDC) light traps without attractant (0.29). No yellow fever virus strain was detected in all the mosquitoes sampled at the four locations.
CONCLUSION
this study suggests that Aedes albopictus are the mosquitoes commonly biting around houses associated with farms. More so, yellow fever virus was not detected in the mosquitoes probably due to the mass vaccination exercise that was carried out the previous year in the study area. More studies are required using the m-HLC to determine the infection rate in this endemic area.
Topics: Animals; Aedes; Nigeria; Yellow fever virus; Mosquito Vectors; Yellow Fever; Humans
PubMed: 38828420
DOI: 10.11604/pamj.2024.47.120.39462 -
Le Infezioni in Medicina 2024Dengue fever is a mosquito-borne viral infection that continues to pose a significant public health threat globally, including Nigeria. Here, we provided a review of... (Review)
Review
Dengue fever is a mosquito-borne viral infection that continues to pose a significant public health threat globally, including Nigeria. Here, we provided a review of dengue fever outbreaks in Nigeria from 1972 to 2023, examining the epidemiology, prevention strategies, challenges faced in combating the disease, and recommendations to mitigate its spread and transmission. We utilized scholarly databases such as PubMed and Google Scholar in writing this paper. The search keywords like, "dengue fever", "break-bone fever", "dengue fever virus" "outbreak", "Nigeria", "prevalence", and "epidemiology", were used to get appropriate published articles about the subject areas. Over the past five decades, Nigeria has experienced intermittent outbreaks of dengue fever, with varying degrees of severity and geographic distribution. Factors such as urbanization, climate change, and inadequate healthcare infrastructure have contributed to the resurgence and spread of the disease in the country. Despite efforts to control dengue transmission through vector control measures and public health interventions, challenges persist, including limited surveillance capacity, diagnostic delays, and gaps in vector control strategies. The emergence of new dengue virus serotypes and the potential for co-circulation with other arboviruses further complicate control efforts. This review highlights the importance of strengthening surveillance systems, enhancing vector control measures, improving diagnostic capabilities, and increasing public awareness to effectively mitigate the burden of dengue fever in Nigeria. Collaboration between government agencies, healthcare providers, researchers, and international partners is crucial in addressing the growing threat of dengue fever and reducing its impact on public health in Nigeria.
PubMed: 38827833
DOI: 10.53854/liim-3202-5 -
Journal of Infection and Public Health Jul 2024We aimed to describe the landscape, including molecular, epidemiological, and clinical aspects of CHIKV infections in the Ribeirao Preto region, an area endemic to...
We aimed to describe the landscape, including molecular, epidemiological, and clinical aspects of CHIKV infections in the Ribeirao Preto region, an area endemic to dengue. We randomly screened 3744 plasma samples that had undergone DENV diagnosis to evaluate CHIKV-RNA using an in-house RT-PCR assay. Positive samples were followed clinically, and RNA samples were submitted to whole genome sequencing. Seventeen cases (0.5 %) were positive for CHIKV-RNA despite being negative for DENV-RNA. Notably, half of the patients experienced prolonged arthralgia lasting more than 90 days. Compared with the healthy control group, leukopenia and thrombocytopenia were observed in all CHIKV-positive individuals with statistically significant P values (P < 0.0001 and P = 0.0003, respectively). The genomic analysis revealed that the CHIKV strains being studied are classified within the East-Central-South-African (ECSA) genotype. This analysis identified new mutations, E1: K211E and E2: V264A, while the previously known mutation E1: A226V was not detected among these strains. This study highlights the need for epidemiological surveillance and preparedness for potential CHIKV epidemics in Brazil, particularly where other arboviruses co-circulate.
Topics: Humans; Brazil; Chikungunya Fever; Chikungunya virus; Dengue; Male; Female; Adult; Genotype; Middle Aged; RNA, Viral; Young Adult; Endemic Diseases; Adolescent; Whole Genome Sequencing; Aged; Child; Phylogeny; Mutation; Child, Preschool; Dengue Virus; Thrombocytopenia
PubMed: 38820892
DOI: 10.1016/j.jiph.2024.04.026 -
MMWR. Morbidity and Mortality Weekly... May 2024
Topics: Humans; United States; West Nile Fever; Arbovirus Infections; Disease Notification; Adult
PubMed: 38814815
DOI: 10.15585/mmwr.mm7321a2 -
Journal of the American Mosquito... Jun 2024Updating the mosquito fauna occurring in a specific area is crucial, given that certain species serve as vectors capable of transmitting zoonotic arboviruses. This...
Updating the mosquito fauna occurring in a specific area is crucial, given that certain species serve as vectors capable of transmitting zoonotic arboviruses. This scientific note presents the first records of mosquitoes of the tribe Orthopodomyiini in the Yucatan Peninsula. Immature mosquitoes were collected on 2 occasions inside a large tree hole in Felipe Carrillo Puerto, Quintana Roo, Mexico. Thirteen adult specimens, reared from the immatures, were obtained and identified as Orthopodomyia kummi based on external characteristics of females and males. This species has been recorded in Panama, Costa Rica, El Salvador, Guatemala, Mexico, and marginally in the United States, but its presence in the Yucatan Peninsula had gone unnoticed until now. The knowledge about mosquitoes of the genus Orthopodomyia is limited, and their epidemiological importance remains uncertain. Therefore, further studies could provide insights into the ecological and infection dynamics associated with this species.
Topics: Animals; Mexico; Culicidae; Female; Male; Animal Distribution; Larva
PubMed: 38811012
DOI: 10.2987/24-7173 -
PloS One 2024Ae. aegypti is the vector of important μ arboviruses, including dengue, Zika, chikungunya and yellow fever. Despite not being specifically targeted by insecticide-based...
BACKGROUND
Ae. aegypti is the vector of important μ arboviruses, including dengue, Zika, chikungunya and yellow fever. Despite not being specifically targeted by insecticide-based control programs in West Africa, resistance to insecticides in Ae. aegypti has been reported in countries within this region. In this study, we investigated the status and mechanisms of Ae. aegypti resistance in Niamey, the capital of Niger. This research aims to provide baseline data necessary for arbovirus outbreak prevention and preparedness in the country.
METHODS
Ovitraps were used to collect Ae. aegypti eggs, which were subsequently hatched in the insectary for bioassay tests. The hatched larvae were then reared to 3-5-day-old adults for WHO tube and CDC bottle bioassays, including synergist tests. The kdr mutations F1534C, V1016I, and V410L were genotyped using allele-specific PCR and TaqMan qPCR methods.
RESULTS
Ae. aegypti from Niamey exhibited moderate resistance to pyrethroids but susceptibility to organophosphates and carbamates. The kdr mutations, F1534C, V1016I and V410L were detected with the resistant tri-locus haplotype 1534C+1016L+410L associated with both permethrin and deltamethrin resistance. Whereas the homozygote tri-locus resistant genotype 1534CC+1016LL+410LL was linked only to permethrin resistance. The involvement of oxidase and esterase enzymes in resistance mechanisms was suggested by partial restoration of mosquitoes' susceptibility to pyrethroids in synergist bioassays.
CONCLUSION
This study is the first report of Ae. aegypti resistance to pyrethroid insecticides in Niamey. The resistance is underpinned by target site mutations and potentially involves metabolic enzymes. The observed resistance to pyrethroids coupled with susceptibility to other insecticides, provides data to support evidence-based decision-making for Ae. aegypti control in Niger.
Topics: Animals; Aedes; Insecticide Resistance; Pyrethrins; Niger; Insecticides; Mutation; Mosquito Vectors; Genotype; Larva; Insect Proteins
PubMed: 38809933
DOI: 10.1371/journal.pone.0304550 -
PloS One 2024A low technology emanator device for slowly releasing vapour of the volatile pyrethroid transfluthrin was recently developed in Tanzania that provides robust protection...
BACKGROUND
A low technology emanator device for slowly releasing vapour of the volatile pyrethroid transfluthrin was recently developed in Tanzania that provides robust protection against night biting Anopheles and Culex vectors of malaria and filariasis for several months. Here these same emanator devices were assessed in Dar es Salaam city, as a means of protection against outdoor-biting Aedes (Stegomia) aegypti, the most important vector of human arboviruses worldwide, in parallel with similar studies in Haiti and Brazil.
METHODS
A series of entomological experiments were conducted under field and semi-field conditions, to evaluate whether transfluthrin emanators protect against wild Ae. aegypti, and also compare the transfluthrin responsiveness of Ae. aegypti originating from wild-caught eggs to established pyrethroid-susceptible Ae. aegypti and Anopheles gambiae colonies. Preliminary measurements of transfluthrin vapour concentration in air samples collected near treated emanators were conducted by gas chromatography-mass spectrometry.
RESULTS
Two full field experiments with four different emanator designs and three different transfluthrin formulations consistently indicated negligible reduction of human landing rates by wild Ae. aegypti. Under semi-field conditions in large cages, 50 to 60% reductions of landing rates were observed, regardless of which transfluthrin dose, capture method, emanator placement position, or source of mosquitoes (mildly pyrethroid resistant wild caught Ae. aegypti or pyrethroid-susceptible colonies of Ae. aegypti and An. gambiae) was used. Air samples collected immediately downwind from an emanator treated with the highest transfluthrin dose (15g), contained 12 to 19 μg/m3 transfluthrin vapour.
CONCLUSIONS
It appears unlikely that the moderate levels of pyrethroid resistance observed in wild Ae. aegypti can explain the modest-to-undetectable levels of protection exhibited. While potential inhalation exposure could be of concern for the highest (15g) dose evaluated, 3g of transfluthrin appears sufficient to achieve the modest levels of protection that were demonstrated entomologically. While the generally low levels of protection against Aedes reported here from Tanzania, and from similar entomological studies in Haiti and Brazil, are discouraging, complementary social science studies in Haiti and Brazil suggest end-users perceive valuable levels of protection against mosquitoes. It therefore remains unclear whether transfluthrin emanators have potential for protecting against Aedes vectors of important human arboviruses.
Topics: Animals; Fluorobenzenes; Tanzania; Aedes; Cyclopropanes; Mosquito Control; Insecticides; Mosquito Vectors; Humans; Anopheles; Insect Bites and Stings; Pyrethrins
PubMed: 38809841
DOI: 10.1371/journal.pone.0299722 -
Epidemiologia E Servicos de Saude :... 2024To create a protocol for performing minimally invasive autopsies (MIA) in detecting deaths from arboviruses and report preliminary data from its application in Ceará...
OBJECTIVE
To create a protocol for performing minimally invasive autopsies (MIA) in detecting deaths from arboviruses and report preliminary data from its application in Ceará state, Brazil.
METHODS
Training was provided to medical pathologists on MIA.
RESULTS
A protocol was established for performing MIA, defining criteria for sample collection, storage methods, and diagnoses to be carried out according to the type of biological sample; 43 MIAs were performed in three months. Of these, 21 (48.8%) arrived at the Death Verification Service (SVO) with arboviruses as a diagnostic hypothesis, and seven (16.3%) were confirmed (six chikungunya cases and one dengue case); cases of COVID-19 (n = 9), tuberculosis (n = 5), meningitis (n = 4), cryptococcosis (n = 1), Creutzfeldt-Jakob disease (n = 1), breast cancer (n = 1), and human rabies (n = 1) were also confirmed.
CONCLUSION
The protocol implemented enabled identification of a larger number of suspected arbovirus-related deaths, as well as confirmation of other diseases of interest for surveillance.
MAIN RESULTS
A protocol was developed to perform minimally invasive autopsies (MIAs) in Death Verification Services (SVO), capable of expanding the system's capacity to identify a greater number of deaths suspected to be due to arboviruses.
IMPLICATIONS FOR SERVICES
The experience suggests that in-service trained health professionals are able to perform MIA, and that use of this technique in SVOs has been shown to be capable of increasing the system's sensitivity in detecting deaths of interest to public health.
PERSPECTIVES
Trained professionals will be able to collect biological material in hospitals, through MIA, in cases of interest for health surveillance and when family members do not allow a complete conventional autopsy to be performed.
Topics: Humans; Brazil; Autopsy; Arbovirus Infections; Female; Sensitivity and Specificity; Male; Middle Aged; Adult; Adolescent; Young Adult; Arboviruses; Aged; Population Surveillance; Epidemiological Monitoring; Cause of Death; Child; Child, Preschool
PubMed: 38808901
DOI: 10.1590/S2237-96222024V33E2024008.en