WASHINGTON DC, USA, Tuesday February 7, 2017 — The Pan American Health Organisation (PAHO) says experts now consider Zika to be a long-term public health challenge, following the declaration by the World Health Organisation’s (WHO) Emergency Committee on Zika that the epidemic’s emergency phase is over.
Experts are nevertheless still grappling to understand the mosquito-borne virus as the world marks one year since a global public health emergency was declared over the rapid spread of the virus from Brazil to 75 other countries, including most in the Caribbean and Latin America.
PAHO’s latest update lists 48 countries and territories in the Americas with confirmed transmission of the virus through mosquitoes since 2015, while five countries in the Americas have reported sexually transmitted Zika cases.
Some 200,000 cases have been confirmed, more than half from Brazil, where 2,618 children have been born with confirmed Zika related congenital syndrome.
The risk assessment of Zika has not changed globally, and the virus continues to spread geographically to areas where competent vectors are present, PAHO said.
The latest WHO assessment notes: “Although a decline in cases of Zika infection has been reported in some countries, or in some parts of countries, vigilance needs to remain high.”
PAHO’s Incident Manager for Zika, Dr Sylvain Aldighieri, said that when clusters of babies with microcephaly and cases of Guillain-Barré syndrome were reported at the same time and place as Zika virus outbreaks during the last months of 2015, PAHO published a series of alerts starting in December 2015.
“After PAHO mounted a robust regional response to the outbreak, a turning point came in January 2016 as research provided the first evidence regarding the link between Zika and microcephaly in babies born in Northeast Brazil,” Dr Aldighieri said.
This led to the WHO declaration of a Public Health Emergency of International Concern (PHEIC) on February 1, 2016, PAHO said, adding that Zika spread rapidly not only through the Americas but also to other regions.
PAHO said it continues providing technical support to its member countries in the Americas in all aspects of Zika surveillance and control, with special focus on clinical management, laboratory services and controlling the mosquito vectors of Zika virus, which also transmit dengue, chikungunya and urban yellow fever.
In Washington, a group of experts on public health entomology has been meeting in Washington, with the aim of issuing updated guidance on controlling mosquitos and other vectors of disease through improved surveillance, prevention, integrated vector management, and eventual control and elimination of vector-borne diseases, PAHO said.
It added that regional partners are involved in vector control research, including pilot studies of new control methodologies such as mosquitoes infected by the Wolbachia bacteria.
Although there is no treatment for Zika, PAHO said researchers continue to work on vaccines, with five potential vaccine candidates headed for clinical trials.
It noted that a crucial tool in the long-term fight against Zika is community education and participation in eliminating mosquito vectors and breeding sites.
According to PAHO, more than 1,500 research papers have been published on Zika, confirming that the virus can infect mothers and unborn children and kill brain cells, causing a variety of birth defects.
Researchers continue to find a widening range of effects in “congenital Zika syndrome,” including brain abnormalities, neural tube defects, eye abnormalities, hearing problems, irritability, seizures, feeding difficulties and others, PAHO said.