Work

Control and mitigation of dengue and Zika virus transmission in a hospital in Recife, Brazil: a successful experience with an integrated control program against Aedes aegypti

Year: 2026

Type: article

Abstract: BACKGROUND: The presence of Aedes aegypti in healthcare facilities represents a significant epidemiological threat, as it is the primary vector of dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses. In the absence of effective alternatives to chemical insecticides for eliminating adult mosquitoes, healthcare facilities may become focal points for arbovirus transmission, compromising the safety of patients and healthcare employees. Vector control remains the main approach for mitigating arbovirus transmission. This study investigated the impact of an effective integrated control program (ICP) implemented in a hospital in Recife, Pernambuco, Brazil, where arbovirus circulation in mosquitoes was detected. METHODS: Entomological monitoring was conducted through mechanical aspiration inside the Hospital das Clínicas (HC). Specimens were counted, identified, grouped by species, classified according to blood-feeding status, and recorded by capture station. Viral infection was assessed using nonstructural protein 1 (NS1) by enzyme-linked immunosorbent assay (ELISA) and a triplex reverse transcription quantitative polymerase chain reaction (RT-qPCR) for the detection of DENV, ZIKV, and CHIKV. Infection rates were calculated using the minimum infection rate (MIR). ICP actions included environmental management, larvicide application at breeding sites, ovitraps to collect and destroy eggs, toxic sugar baits, and intensified mechanical aspiration to eliminate adult mosquitoes. Three phases were defined: pre-ICP (initial survey), ICP (all actions), and post-ICP (larvicidal treatment). RESULTS: During the ICP, a sustained reduction in female mosquito density was observed, reaching 99% for Ae. aegypti and 88% for Culex quinquefasciatus. Six months after ICP, ELISA detected infected females in 9 of 14 stations (64%). The MIR for Ae. aegypti decreased from 50 to 44, while Cx. quinquefasciatus showed a slight increase. RT-qPCR revealed 11 ZIKV-positive pools (eight Ae. aegypti and three Cx. quinquefasciatus). After 12 months of ICP, only one Ae. aegypti DENV-positive pool was detected by both techniques in a single station (pediatrics). Both techniques detected infection even in pools containing a single female, underscoring their high sensitivity. At 18 months of ICP, all pools tested negative for arboviruses. CONCLUSIONS: Molecular and antigen-based approaches confirmed the mitigation of arbovirus circulation in hospital-associated mosquitoes, demonstrating that the continuous elimination of Ae. aegypti females (> 99%) is critical in these settings to prevent nosocomial transmission.

Source: Parasites & Vectors

DOI: 10.1186/s13071-025-07241-9