Another kind of Zika public health emergency
Published: 11 February 2017
A year ago, on Feb 1, 2016, WHO declared the Zika virus epidemic a public health emergency. In a brave show of leadership no doubt spurred by the embarrassment of failing to act sooner on the Ebola outbreak threats, Director-General Margaret Chan sounded the alarm about the potential links between Zika virus and rising neurological disorders despite a lack of conclusive data. By doing so she stimulated an international collective effort, scientific research, and funding that helped stabilise the crisis.
A year on she has reflected on the rightness of that decision, writing in a commentary on WHO's website that it strengthened integrated surveillance for mosquito-borne viruses, and accelerated understanding of the modes of transmission and the abnormalities associated with congenital Zika virus syndrome. The coordination that occurred between international and national authorities and health professionals, especially in Latin American countries, to detect, diagnose, and characterise cases of microcephaly is commendable.
But the warm glow of that reflection must be tempered by the challenges ahead. It would be tempting to laud the Zika response as a success and redirect attention to other emergent issues. To do so would ignore the continued spread of Zika virus and its under-appreciated long-term effects. As WHO shifts direction under a new Director-General, we need even bolder Zika leadership that keeps victims and their families firmly on our public health agenda.
As of Feb 1, 2017, the number of countries reporting a Zika virus outbreak since 2015 has grown to 59, 48 of them in North and South America. Seven countries have reported active local transmission of the virus in 2016 or 2017. 13 countries report person-to-person transmission. New affected areas have emerged including Angola, already struggling under yellow fever and cholera epidemics, which reported its first two cases in January.
Continued geographical spread of Zika virus would be a challenge enough were it not for the anticipated long-term effects. Chan's commentary says WHO “must be ready for the long-haul” but misses the opportunity to urge and specify international attention, research, and resources for the individuals left devastated by Zika virus. It leaves invisible the needs of thousands of children, their families, and future families; and overlooks the responsibility of the world's community to support them.
Indeed, Zika can only be considered a long-term epidemic. 6 months ago Bruce Aylward, then head of WHO's outbreaks and health emergencies cluster, told The Lancet that “we don't know what the full spectrum of the Zika-caused congenital defects will be. Will apparently unaffected children whose mothers had Zika virus infection in pregnancy develop normally? Will they be able to walk and talk normally? Will they be mentally impaired or have other problems that only become evident years later?” We still don't know. Fully supported research to understand, track, and address the long-term sequelae of congenital, perinatal, and paediatric Zika virus infection on children's development must be prioritised.
Currently, almost 3000 cases of Zika-related microcephaly or other CNS defects have been recorded in 29 countries. Brazil has been hardest hit: 2366 babies have been born to Zika-infected women and their families, many already vulnerable and lacking the resources to shoulder the burdens of care. Whereas some of these affected children will lead normal lives, many others with congenital Zika virus syndrome will experience severe disability and need long-term medical attention. Medical interventions could involve intensive physical therapy, treatments for neurological impairments, feeding tubes, and others.
The US Centers for Disease Control has estimated the costs of treating such children to be tens of millions of dollars. And microcephaly is likely to represent only a portion of those affected. Others will be born blind or deaf, or suffering from seizures, irritability, or swallowing disorders. Even in the absence of microcephaly, congenital brain abnormalities might be present. That Zika virus infection can trigger the autoimmune disorder Guillain-Barré syndrome in adults worsens the long-term effects. A portion of those affected will die without access to respiratory and intensive care; many more will live with disability.
Adding to Zika's economic drain on societies because of lost productivity due to neurological deficits, these medical consequences amount to another kind of Zika public health emergency.
As the world waits for a vaccine, public health efforts will necessarily focus on prevention in the form of mosquito control and travel advisories. But health agencies like WHO, public health researchers, and policy makers must also not forget the individuals affected. They require our unrelenting attention.
For The Lancet's Zika virus resource centre see http://www.thelancet.com/campaigns/zika