August 2017 – Zika Infection In Singapore 1 Year On

Clusters of locally transmitted Zika infection were first reported in August 2016 and a total of 458 cases of Zika infection were reported in Singapore by end December 2016. In the first 32 weeks in 2017, there have been 61 cases of Zika infection notified. In 2016 and up to the first half of 2017, of the 3 mosquito borne viral infections, dengue infection is the most common followed by Zika virus infection, with Chikungunya infection being the least common.

Globally, the main concern for Zika virus infection is the impact of the infection on the unborn fetus when pregnant women acquire the infection. In the past 6 months, preliminary data from Zika Pregnancy registries have highlighted that the major risk of birth defects occur when Zika infection occurs in the first trimester of pregnancy. The Zika virus induced birth defects will have a long term impact not just on the parents but also on society. A UNDP report published in April 2017 estimated that the socio-economic impact of Zika virus infection in Latin America and the Caribbean will total 7-18 billion US dollars from 2015 to 2017. The long term consequences of Zika virus infection may undermine decades of social development in the less developed countries.

What are the implications for Singapore? It does appear that Zika virus is here to stay and we remain at risk for outbreaks of this virus. In the first 2 weeks of August 2017, there have been small clusters of Zika infection in Serangoon North. What has been reassuring is that the total number of new cases remain low and we must acknowledge the National Environment Agency’s diligent efforts in vector control in Singapore. The Aedes vector population in Singapore has been kept in check. The benefit of these vector control efforts have also resulted in dramatic reductions in dengue infections in Singapore for the first half of 2017.

The need for primary prevention of Zika virus infection cannot be over-emphasized. These recommendations include counselling pregnant patients to restrict travel to Zika-endemic areas, minimise mosquito exposure, and use barrier protection with potentially exposed sexual partners. At this time, there are no Zika vaccines commercially available. There is active ongoing research in the area of vaccine development. Hopefully, an effective Zika vaccine will become available in the next 5 years and this will add to the prevention and control efforts.