Arboviral diseases and poverty in Alabama, 2007-2017.

Mosquito-borne viruses cause diseases of great public health concern. Arboviral disease case distributions have complex relationships with socioeconomic and environmental factors. We combined information about socio-economic (population, and poverty rate) and environmental (precipitation, and land use) characteristics with reported human cases of arboviral disease in the counties of Alabama, USA, from 2007-2017. We used county level data on West Nile virus (WNV), dengue virus (DENV), chikungunya virus (CHIKV), Zika virus (ZIKV), California serogroup virus, Eastern equine encephalitis virus, and Saint Louis encephalitis virus to provide a detailed description of their spatio-temporal pattern. We found a significant spatial convergence between incidence of WNV and poverty rate clustered in the southern part of Alabama. DENV, CHIKV and ZIKV cases showed a different spatial pattern, being mostly located in the northern part, in areas of high socioeconomic status. The results of our study establish that poverty-driven inequities in arboviral risk exist in the southern USA, and should be taken into account when planning prevention and intervention strategies.

Vaccine Demand and Willingness-to-pay for Arbovirus Vaccines: A Cross-sectional Survey in Rural Guatemala.

BACKGROUND: Arboviruses including dengue (DENV), chikungunya (CHIKV) and Zika cause significant morbidity in Latin America. With multiple arbovirus vaccines in development, better understanding of community attitudes and acceptability for these vaccines is needed. METHODS: In September 2016, a cross-sectional survey assessed arbovirus knowledge, attitudes, vaccine demand and willingness-to-pay (WTP) at the conclusion of a DENV/norovirus surveillance study in rural Guatemala with high arbovirus endemicity. Factors associated with vaccine demand and WTP were assessed with regression analysis. RESULTS: Among 564 surveyed households, DENV knowledge was high. There was great concern for arboviruses, particularly CHIKV. Overall vaccine attitudes were positive with <5% identifying significant barriers, hesitancy or refusing previous vaccination. At 50% and 75% efficacy, 75% and 88% of respondents wanted arbovirus vaccines, respectively. DENV vaccine demand at 50% efficacy was associated with increased housing density, nonhealth postvaccination location, older children and medical source for information. For each vaccine, 52-55% of respondents were WTP $0-$3.40, while 16-17% were WTP ≥$6.81. WTP at $3.40 and $6.81 levels for all vaccines was associated positively with parental education but negatively with good DENV knowledge. History of purchasing and identifying barriers to vaccines was associated with WTP ≥$6.81. CONCLUSIONS: Demand for potential DENV, CHIKV and Zika vaccines is high at 50% and 75% efficacy in this Guatemalan community. Associated factors could be leveraged to optimize arbovirus vaccine implementation. Overall low WTP given current cost of Dengvaxia (Sanofi Pasteur, Lyon, France) suggests that government subsidization may be necessary in resource-poor regions, though a small private market may be supported.

The Cost of Arbovirus Disease Prevention in Europe: Area-Wide Integrated Control of Tiger Mosquito, Aedes albopictus, in Emilia-Romagna, Northern Italy.

Aedes albopictus (tiger mosquito) has become the most invasive mosquito species worldwide, in addition to being a well-known vector of diseases, with a proven capacity for the transmission of chikungunya and dengue viruses in Europe as well as the Zika virus in Africa and in laboratory settings. This research quantifies the cost that needs to be provided by public-health systems for area-wide prevention of arboviruses in Europe. This cost has been calculated by evaluating the expenditure of the plan for Aedes albopictus control set up in the Emilia-Romagna region (Northern Italy) after a chikungunya outbreak occurred in 2007. This plan involves more than 280 municipalities with a total of 4.2 million inhabitants. Public expenditure for plan implementation in 2008-2011 was examined through simple descriptive statistics. Annual expenditure was calculated to be approximately €1.3 per inhabitant, with a declining trend (from a total of €7.6 million to €5.3 million) and a significant variability at the municipality level. The preventative measures in the plan included antilarval treatments (about 75% of total expenditure), education for citizens and in schools, entomological surveillance, and emergency actions for suspected viremias. Ecological factors and the relevance of tourism showed a correlation with the territorial variability in expenditure. The median cost of one antilarval treatment in public areas was approximately €0.12 per inhabitant. Organizational aspects were also analyzed to identify possible improvements in resource use.

Epidemiology of arboviral infections.

OBJECTIVE: To review the current state of knowledge regarding the epidemiology of arboviruses. DATA SOURCES: Computerized literature searches, identification of papers through review of article bibliographies, and Yale Arbovirus Research Unit, USA. STUDY SELECTION: Articles documenting research pertaining to the epidemiology of arboviruses with emphasis on factors that increase or decrease the spread of these infections. DATA EXTRACTION: The review articles were extracted independently by the authors. DATA SYNTHESIS: Arboviral infections are a global health problem accounting for significant morbidity and mortality in human and animal populations. They belong to the families Togaviridae, Flaviviridae, Bunyaviridae, Reoviridae, and Rhabdoviridae, and are transmitted to humans and domestic animals by the bite of infected arthropods. Rodents and birds are significant vertebrate hosts, while humans are usually not involved in the maintenance and spread of most arboviruses. Ecologic changes and human behavior are important in the spread of these infections. Clinical features range from mild fevers to fatal encephalitis. Surveillance, immunization, and vector control are important methods of prevention. CONCLUSION: It appears that the distribution and spread of arboviruses is greatly influenced by human behavior and ecologic changes in the environment. Awareness regarding these and other factors, such as travel history, history of bites of arthropods, concurrent epidemic pattern in the community, and knowledge of surveillance data are useful ways of identifying these infections. Future research may be directed toward methodical search for new arboviruses and their relation to human and animal disease.