RESUMO
Objective: The objective of this work was to adapt a diagnostic kit developed for humans to identify Dengue (DENV1, DENV2, DENV3, DENV4), Zika (ZIKV) and Chikungunya virus (CHIKV) in females of Aedes aegypti and Aedes albopictus and to verify if the occurrence of mosquitoes infected with these three arboviruses are being found in regions with high occurrence of these diseases in humans. Materials and Methods: For this purpose, live mosquitoes were captured between January and June 2020 using 3,476 traps permanently installed in the field were used. After capture, the species were identified, then the females were placed in a pool of 2 to 10 specimens and sent to the laboratory for detection of DENV1, DENV2, DENV3, DENV4, ZIKV and CHIKV by RT-PCR using a commercial human kit for arboviruses. Results: Of the 76 mosquito pools collected, six (7.9%) pools tested positive for the DENV2 virus. The DENV-positive mosquitoes were collected in regions with a high incidence of reported cases of Dengue or in adjacent areas. Conclusion: The absence of kits for the detection of these arboviruses in Aedes is a limiting factor and the adequacy of commercial kits, already used for the diagnosis of arboviruses in humans, the results presented demonstrate that it is possible to identify the presence of DENV2 in mosquitoes with the respective kit, reinforcing the use of RT-qPCR as a robust diagnostic tool for epidemiological surveillance allowing managers to receive timely results for decision-making regarding prevention and control actions.
Assuntos
Aedes , Arbovírus , Febre de Chikungunya , Vírus Chikungunya , Vírus da Dengue , Dengue , Infecção por Zika virus , Zika virus , Feminino , Humanos , Animais , Zika virus/genética , Vírus Chikungunya/genética , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/veterinária , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/veterinária , Brasil/epidemiologia , Saúde Pública , Argentina , Paraguai , Vírus da Dengue/genética , Mosquitos Vetores , Dengue/epidemiologia , Dengue/veterináriaRESUMO
This study aimed to identify the seroprevalence of chikungunya and its associated factors in the city of Quixadá, Ceará, Brazil. We also aimed to identify the spatial distribution patterns of positive cases. A cross-sectional survey was conducted with a questionnaire about clinical symptoms, socioeconomic and demographic factors, and a 10 ml blood sample was collected and analysed by ELISA. For the bivariate analysis, we use the chi-square test, a prevalence ratio and its 95% confidence interval. A robust Poisson hierarchical regression was used to adjust for confounders. The Kernel density was performed for the spatial analysis. A total of 409 samples were analysed; of them, 70.7% were seropositive for previous exposure to chikungunya virus (CHIKV). High seropositivity for CHIKV was higher in female participants (75.5%; PR = 1.23; 95% CI: 1.06-1.43), those aged 31 years or more (74.3%; PR = 1.62; 95% CI: 1.04-2.52), and those with elementary education level (75.0%; PR = 1.30; 95% CI: 1.06-1.60). There were also high seroprevalence in those with less than a minimum wage per month (89.5%; PR = 1.59; 95% CI: 1.11-2.30), housewives (87.5%; PR = 1.64; 95% CI: 1.24-2.18) and unemployed (80.0%; PR = 1.50; 95% CI: 1.10-2.06). After adjusting for age, morning stiffness was the only chikungunya symptom that remained associated (PR = 1.20; 95% CI: 1.06-1.37; p < .001). There was an area of high density of cases in the downtown and two areas of medium density in nearby regions. Otherwise, the higher seroprevalence rates were in the peripherical neighbourhoods. There is a hyperendemicity of CHIKV in Quixadá, and most cases are spatially contiguous. The main associated clinical sign is morning stiffness, but other factors such as low income and spending a longer time at home were significantly associated with higher seroprevalence.
Assuntos
Arbovírus , Febre de Chikungunya , Animais , Anticorpos Antivirais , Brasil/epidemiologia , Febre de Chikungunya/epidemiologia , Febre de Chikungunya/veterinária , Estudos Transversais , Feminino , Humanos , Estudos Soroepidemiológicos , Inquéritos e QuestionáriosRESUMO
Deployment of Wolbachia to mitigate dengue (DENV), Zika (ZIKV) and chikungunya (CHIKV) transmission is ongoing in 12 countries. One way to assess the efficacy of Wolbachia releases is to determine invasion rates within the wild population of Aedes aegypti following their release. Herein we evaluated the accuracy, sensitivity and specificity of the Near Infrared Spectroscopy (NIRS) in estimating the time post death, ZIKV-, CHIKV-, and Wolbachia-infection in trapped dead female Ae. aegypti mosquitoes over a period of 7 days. Regardless of the infection type, time post-death of mosquitoes was accurately predicted into four categories (fresh, 1 day old, 2-4 days old and 5-7 days old). Overall accuracies of 93.2, 97 and 90.3% were observed when NIRS was used to detect ZIKV, CHIKV and Wolbachia in dead Ae. aegypti female mosquitoes indicating NIRS could be potentially applied as a rapid and cost-effective arbovirus surveillance tool. However, field data is required to demonstrate the full capacity of NIRS for detecting these infections under field conditions.
Assuntos
Aedes/microbiologia , Aedes/virologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/veterinária , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/veterinária , Feminino , Ensaios de Triagem em Larga Escala/métodos , Fatores de Tempo , Wolbachia , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/veterináriaRESUMO
BACKGROUND: Dengue, chikungunya and Zika viruses (DENV, CHIKV and ZIKV) are transmitted in sylvatic transmission cycles between non-human primates and forest (sylvan) mosquitoes in Africa and Asia. It remains unclear if sylvatic cycles exist or could establish themselves elsewhere and contribute to the epidemiology of these diseases. The Caribbean island of St. Kitts has a large African green monkey (AGM) (Chlorocebus aethiops sabaeus) population and is therefore ideally suited to investigate sylvatic cycles. METHODS: We tested 858 AGM sera by ELISA and PRNT for virus-specific antibodies and collected and identified 9704 potential arbovirus vector mosquitoes. Mosquitoes were homogenized in 513 pools for testing by viral isolation in cell culture and by multiplex RT-qPCR after RNA extraction to detect the presence of DENV, CHIKV and ZIKVs. DNA was extracted from 122 visibly blood-fed individual mosquitoes and a polymorphic region of the hydroxymethylbilane synthase gene (HMBS) was amplified by PCR to determine if mosquitoes had fed on AGMs or humans. RESULTS: All of the AGMs were negative for DENV, CHIKV or ZIKV antibodies. However, one AGM did have evidence of an undifferentiated Flavivirus infection. Similarly, DENV, CHIKV and ZIKV were not detected in any of the mosquito pools by PCR or culture. AGMs were not the source of any of the mosquito blood meals. CONCLUSION: Sylvatic cycles involving AGMs and DENV, CHIKV and ZIKV do not currently exist on St. Kitts.
Assuntos
Febre de Chikungunya/transmissão , Febre de Chikungunya/veterinária , Chlorocebus aethiops/virologia , Dengue/transmissão , Dengue/veterinária , Infecção por Zika virus/transmissão , Infecção por Zika virus/veterinária , Aedes/genética , Aedes/virologia , Animais , Anticorpos Antivirais/sangue , Vírus Chikungunya/genética , Vírus Chikungunya/imunologia , Vírus da Dengue/genética , Vírus da Dengue/imunologia , Feminino , Humanos , Hidroximetilbilano Sintase/genética , Mosquitos Vetores/genética , Mosquitos Vetores/virologia , São Cristóvão e Névis , Zika virus/genética , Zika virus/imunologiaRESUMO
A population of white-tailed deer ( Odocoileus virginianus) resides throughout the island of St. John, US Virgin Islands, predominately in the Virgin Islands National Park. Adult deer ( n=23), ranging from 1 yr to 8 yr old, were assessed to characterize body condition and health. Serologic samples were screened for important viral pathogens in the area, including Zika, chikungunya, bluetongue, and epizootic hemorrhagic disease viruses. Samples were collected in July 2016; males were in velvet and all females were in diestrus. Deer had recovered from a severe drought the previous year but were generally healthy, with a low-level but high incidence of tick parasitism. Marked statistically significant changes in hematocrit and hemoglobin levels were associated with the effects of the anesthetic mixture used for capture. No other statistically significant differences were observed. Serum from four deer induced reduction in Zika virus plaques, suggesting possible exposure. No serum was reactive for chikungunya virus. Bluetongue and epizootic hemorrhagic disease antibodies were present in 50% of the sampled deer, but no clinical signs associated with disease were observed during the study period. These data will be valuable for future dynamic health assessment and may help assess changes to the population, such as those induced by climate change, infectious disease, or other demographic events.