Heavily featured in recent news for its rapid spread through South America, Zika is a mosquito-borne virus with no established vaccine or prevention methods. Although Zika contraction is often characterized by little to no symptoms, pregnant women may pass the virus onto their fetuses, resulting in birth defects such as microcephaly. Previously, it was believed that mosquitoes could only contract the virus by biting an infected host. However, new research shows that female mosquitoes carrying the Zika virus can pass the infection onto their offspring via vertical transmission.
The study, published in the Journal of Tropical Medicine and Hygiene, elucidated that infected eggs of the Aedes aegypti can survive for months on dry surfaces, ensuring the virus’ survival in cold or dry conditions even without a vertebrate host. Thus, the Zika virus will persist even if all adult mosquitoes were eliminated because the mosquito’s offspring can carry the virus into the next generation. This further complicates current measures to combat Zika transmission.1 Luckily, not all species of mosquito can transmit the Zika virus through vertical transmission.2 It should also be noted that the study observed mosquitoes in a laboratory setting as opposed to the wilderness, which could impact the generalizability
of the results.
The conclusions from the study can be used to improve the current methods for combating Zika transmission. Recommended interventions include the use of insecticides, the elimination of standing water, and the release of genetically-modified mosquitoes that sterilize the mosquito populace or hinder vertical viral transmission.
By Angela Dong
References may be found in the journal