Dr Poonam Khetrapal Singh
The strongly suspected link between Zika virus and infants being born with unusually small heads and other neurological disorders has been declared by WHO a Public Health Emergency of International Concern. There is an urgent need to coordinate efforts at the global level to investigate and understand the relationship between these conditions better, just as there is a need to take all measures necessary to prevent Zika’s spread. The implications for WHO’s South-East Asia Region are many: the potential for the virus to spread – and to do so rapidly – is real. In addition, cases that could lead to alarming complications for pregnant women and their newborns may be going unnoticed. In a Region that comprises 26% of the world’s population, the stakes are high.
The South-East Asia Region is vulnerable. Its large urban populations, tropical climate and often poor waste management have the potential to facilitate a Zika epidemic. And the Region is already home to the Aedis aegypti mosquito that spreads the disease. Each monsoon the Aedes aegypti transmits dengue and chikungunya throughout South-East Asia resulting in illness and death – an endemic crisis that health authorities have been battling for decades. While Zika is said to have been detected in the Region as early as the 1950s, and sporadic cases have been reported in recent years in Thailand and the Maldives, its prevalence – and immunity against it – remains unknown.
Due to Zika’s relatively mild symptoms, which appear in just one in every five people infected, disease surveillance has, historically, focused on detecting and treating known killers. Zika’s temporal and spatial association with microcephaly and Guillain-Barre syndrome, coupled with its explosive spread across the Americas, changes the equation radically. Though the dangers of Zika for those who are not pregnant, or who are not planning on getting pregnant, are limited, increased circulation heightens the possibility a pregnant woman will become infected. While there is much that we don’t know about the disease and its potential link with complications in newborns, until science charts a way out we must be vigilant. Managing the risk demands governments and their citizens follow smart public health practices that we know work.
Scaling-up existing mosquito control programs is essential. Breeding sites must be disrupted; larvae must be smothered; and adult mosquito populations must be eliminated. Doing this will diminish the Aedes aegypti population responsible for not only Zika transmission but dengue and chikungunya as well. This will also help control mosquitos that spread potentially deadly diseases such as malaria, lymphatic filariasis and Japanese encephalitis. With the monsoon due to arrive in June, it is imperative that these measures are taken at the soonest. Governments must also increase surveillance for Zika, microcephaly, Guillain-Barre syndrome and other neurological disorders. Increased surveillance will enhance the ability of authorities to act in the event of an epidemic, and will advance understanding of the suspected causal relationship between the conditions. Diagnostic tools within the Region – including laboratory testing – must be expanded, while health workers must be sensitized and encouraged to report suspected cases.
We must also take personal action. The best way to stop Zika transmission is for each of us to cover our skin and avoid mosquito bites. Though other possible means of infection have been suggested, transmission via mosquito-bite remains the primary threat. Key personal protective measures to take include wearing clothes that cover the arms and ankles, wearing insect repellant and sleeping under a mosquito net. Around the house, close doors, use window screens and ensure vessels for standing water – such as empty tires, flower pots and buckets – are emptied daily so that mosquitos cannot breed in them. And be vigilant: Aedis aegypti mosquitos are aggressive day-biters, though they can also strike at night, meaning round-the-clock care is needed.
As part of these efforts, effective and responsible communication is vital. Governments must engage with and mobilize communities to support mosquito control programs, and must provide vulnerable groups real-time information on evolving risks. They must also ensure that responsible information is provided to their populations regarding travel, and must desist from providing advice that could spread unnecessary alarm. Misinformation diminishes trust and instead sows fear. This can debilitate an emergency response. Communities, meanwhile, must engage openly with health authorities and seek clarification where needed. Facts must inform action, and are the greatest tool we have to secure our collective health.
In response to the strongly suspected link between Zika, microcephaly and other neurological disorders in newborns, WHO has mobilized its full organizational capacity and is supporting governments and their citizens to take action. This includes mobilizing human and material resources, enhancing surveillance and laboratory capacity, and streamlining information flows as mandated by International Health Regulations. These practical measures are being complemented by WHO’s spearheading of concentrated research efforts to determine the precise relationship, if any, between the Zika virus, microcephaly and other neurological disorders.
Until the science is in, prudence demands immediate and unswerving action. In the South-East Asia Region, we cannot afford to be complacent.