The World Health Organization (WHO)/ Pan American Health Organization (PAHO) believe that the Zika virus will continue it’s spread throughout the countries and territories of the Americas (the one’s with the appropriate vector), they noted in a statement yesterday.

Western hemisphere map Public domain image/ E Pluribus Anthony
Western hemisphere map
Public domain image/ E Pluribus Anthony

The reason for this prediction is two-fold: You have a naive population concerning immunity to Zika virus (much like Chikungunya virus two years ago) and with the exception of Canada and continental Chile, the Aedes mosquito vector is present in all other countries.

The PAHO says the most effective forms of prevention are (1) reducing mosquito populations by eliminating their potential breeding sites, especially containers and other items (such as discarded tires) that can collect water in and around households; and (2) using personal protection measures to prevent mosquito bites (see also recommendations below).

The role of Aedes mosquitoes in transmitting Zika is documented and well understood, while evidence about other transmission routes is limited. Zika has been isolated in human semen, and one case of possible person-to-person sexual transmission has been described. However, more evidence is needed to confirm whether sexual contact is a means of Zika transmission.

Zika can be transmitted through blood, but this is an infrequent mechanism. Standard precautions that are already in place for ensuring safe blood donations and transfusions should be followed.

Evidence on mother-to-child transmission of Zika during pregnancy or childbirth is also limited. Research is currently under way to generate more evidence regarding perinatal transmission and to better understand how the virus affects babies.

There is currently no evidence that Zika can be transmitted to babies through breast milk. Mothers in areas with Zika circulation should follow PAHO/WHO recommendations on breastfeeding (exclusive breastfeeding for the first 6 months, followed by continued breastfeeding with complementary foods up to 2 years or beyond).