A Safe Strategy

A Safe Strategy
23 Jan 2017

Wolbachia-based vector-control strategies have been recommended by WHO as means to enhance the currently existing measures for controlling dengue.

The use of Wolbachia for the control of mosquito-borne viruses has been examined and unconditionally approved by the Malaysian Medical Research and Ethics Committee (MREC), after considering a risk assessment.

More than ten other countries have considered and approved the release of Wolbachia mosquitoes in the field, and risk assessments have returned ratings of negligible overall risk. These countries include Australia, Vietnam, Indonesia, Thailand, Singapore, China, Brazil, Colombia, French Polynesia, and the USA [the majority including Malaysia are aiming for population replacement, while a related approach being taken in several countries is to only release males carrying incompatibility-generating Wolbachia to suppress mosquito populations; however, this approach likely requires that releases continue indefinitely since mosquito populations can quickly rebound once releases cease].

Some possible risks are summarized in the table below.


Risk estimate

Risk estimate definitions

Negligible (N)

Risk is insubstantial and there is no present need to invoke actions for mitigation.

Low (L)

Risk is minimal, but may invoke actions for mitigation beyond normal practices.

Moderate (M)

Risk is of marked concern that will necessitate actions for mitigation that need to be demonstrated as effective.

High (H)

Risk is unacceptable unless actions for mitigation are highly feasible and effective.