Washington, Feb. 1, 2017 (PAHO/WHO)-As the world marks one year since a global Public Health Emergency was announced due to the rapid spread of Zika from Brazil to and then to 75 other countries, experts are grappling to understand more about this new virus. They are exploring ways to improve the response to outbreaks, including research on integrated management of the mosquitos that transmit the disease.
According to the latest update from the Pan American Health Organization/ World Health Organization, 48 countries and territories in the Americas have confirmed transmission of Zika virus disease through mosquitoes since 2015 and five countries in the Americas have reported sexually transmitted Zika cases. Some 200,000 cases have been confirmed, more than half from Brazil, and there were 2,618 children born with confirmed congenital syndrome associated with Zika virus infection, most in Brazil.
Globally, the risk assessment of Zika has not changed and the virus continues to spread geographically to areas where competent vectors are present. "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," the latest WHO assessment notes.
Dr. Sylvain Aldighieri, PAHO's Incident Manager for Zika, noted 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," he said
This led to the WHO declaration of a Public Health Emergency of International Concern (PHEIC) on February 1, 2016, and Zika spread rapidly not only through the Americas but also to other regions.
In the Americas, PAHO continues providing technical support to its Member Countries in all aspects of Zika surveillance and control, with a special focus on clinical management, laboratory services and controlling the mosquito vectors of Zika virus, which also transmit dengue, chikungunya and urban yellow fever.
A group of experts on Public Health Entomology is meeting in Washington this week, and aims to issue 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. Regional partners are involved in vector control research including pilot studies of new control methodologies such as mosquitoes infected by the Wolbachia bacteria. A crucial tool in the long-term fight against Zika is community education and participation in eliminating mosquito vectors and breeding sites.
While there is no treatment for Zika, researchers are working on vaccines, with five potential vaccine candidates headed for clinical trials. 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.
Experts now consider Zika to be a long-term public health challenge, following the declaration by WHO's Emergency Committee on Zika that the epidemic's emergency phase was over. As response continues, longer-term efforts continue in ways to improve detection, prevention, care and support. Research is also focusing on ways to strengthen preparedness and response in affected countries.