Prevention and control
Vector control operations framework for Zika virus
Zika virus is primarily transmitted by the Aedes species of mosquito which is also responsible for the spread of dengue, Chikungunya and yellow fever viruses. In most areas, the primary vector of these viruses is Aedes aegypti, with Aedes albopictus a proven or potential vector in some settings. Well-implemented vector control against Aedes using existing tools effectively reduces the transmission of viruses spread by these vectors. Pilot studies are being undertaken on new tools which have potential for future reductions in Aedes populations.
Entomological surveillance for Aedes spp. in the context of Zika virus
Entomological surveillance of Aedes mosquitoes is used for operational (and research) purposes to determine changes in geographical distribution, for monitoring and evaluating control programmes, for obtaining relative measurements of the vector population over time, and for facilitating appropriate and timely decisions regarding interventions. There are a number of methods for monitoring vectors (mostly Aedes aegypti) of arboviral diseases. However, the selection and use of a method requires a clear understanding of the surveillance objectives, the availability of skills and resources, and in some instances the level of infestation.
This document describes selected sampling methods that can be used to conduct surveillance of Aedes mosquitoes, pupae and oviposition. It is intended for qualified entomologists at national and sub-national level who are responsible for the surveillance of local Aedes populations.
Maintaining a safe and adequate blood supply during Zika virus outbreaks
These guidelines have been developed in recognition that infection with Zika virus may present a risk to blood safety, and in consideration of the declaration on 1 February 2016 by the WHO Director-General of a Public Health Emergency of International Concern with regard to clusters of microcephaly and other neurological disorders, potentially associated with Zika virus. Currently there is limited knowledge of Zika virus biology and lack of definitive evidence of a link between infection and potential complications. These guidelines will be regularly reviewed and updated as new information becomes available.
Protecting the health and safety of workers in emergency vector control of Aedes mosquitoes
This document provides recommendations on essential measures to protect the health and safety of operators and other persons involved in emergency vector control of Aedes spp. mosquitoes, including space spraying of insecticides, larvicide application and, in some cases, indoor residual spraying. It is intended to be used by vector control managers and operators, public health workers, medical professionals, district health officers and ministries of health.
Monitoring and managing insecticide resistance in Aedes mosquito populations
The use of safe and efficacious insecticides against the adult and larval populations of mosquito vectors is one of the most effective ways to rapidly interrupt transmission of Zika virus, as well as other viruses transmitted by Aedes mosquitoes such as chikungunya and dengue.
Insecticide resistance monitoring in field populations of Aedes is required to determine the levels, mechanisms and geographical distribution of resistance in order to select appropriate insecticides for vector control. Evidence-based decisions will ensure that effective insecticides are selected and used. Changes in insecticide susceptibility status should also direct policy and operational decisions.
This document summarizes WHO test procedures for the detection of insecticide resistance in Aedes larvae and adults including insect growth regulators (IGRs) and Bti products. It also outlines strategies to manageinsecticide resistance in countries facing Zika virus and other viruses transmitted by this species of mosquito.
This document is for qualified entomologists at national and sub-national level who are responsible for evaluating the susceptibility status of local Aedes populations.