Preventing the next Aedes-borne arboviral disease epidemic
Arboviruses (arthropod-borne viruses) are transmitted via blood-feeding arthropods such as mosquitoes, flies, and ticks (1). Aedes mosquitoes are the most important arboviral vectors. The two main species, Aedes aegypti and Aedes albopictus, allow the transmission of viruses such as dengue virus (DENV), chikungunya virus (CHIKV), and Zika virus (ZIKV) (2, 3). The DENV and ZIKV belong to the family Flaviviridae (genus Flavivirus), and the CHIKV is a member of the family Togaviridae (genus Alphavirus) (4, 5). These arboviruses caused outbreaks in several countries belonging to Africa, America, Asia, the Caribbean, and the Pacific (6). More recently, DENV and CHIKV have been reported in Europe, revealing the expansion of these viruses to new and unexpected geographical areas (7, 8). Globalisation, unplanned urbanisation, unreliable public services, climate change, and the deterioration of institutions (e.g., health systems) responsible for mosquito control cause the further expansion of arbovirus.
The global incidence of DENV infection has grown, with about half of the world's population now at risk (9). According to the World Health Organization (WHO), dengue is the most prevalent, dangerous and rapidly spreading arbovirus worldwide (10). Still, dengue is classified as a neglected tropical disease. WHO classifies dengue into two categories: DENV infection with or without warning signs and severe dengue (10). Severe dengue is defined by plasma leakage and/or fluid accumulation leading to shock or respiratory distress, and/or severe bleeding, and/or severe organ impairment (10, 11). Severe DENV infection is a leading cause of serious illness and death in some countries located in Asia and Latin America (10). There are four genetically distinct serotypes of DENV (DENV-1, DENV-2, DENV-3 and DENV-4) and multiple lineages of each serotype, which are often geographically based (12). Recovery from infection of one serotype provides long-term immunity; however, cross-immunity to another serotype after recovery is only partial and temporary. Secondary infection by other serotypes even increases the risk of severe dengue, the antibody-dependent enhancement (ADE) phenomenon (9, 13). In Curaçao, all four dengue serotypes (DENV 1–4) have circulated during the past two decades. According to local health authorities, dengue epidemics occur cyclically, and no severe dengue cases have been reported yet in Curaçao.