The detailed report on Singapore’s multi-faceted approach at containing and investigating last year’s Zika outbreak has finally been published online at Lancet Infectious Diseases. I had written superficially about some of the events in a series of blog posts at that time, but this published work describes comprehensively both the clinical and public health aspects of managing the outbreak (omitting public health communications, which is important but often under-appreciated and discussed) -including the all-important work of vector control – as well as the research that was performed on the entomological, molecular, and clinical aspects of Zika in Singapore.

Beautiful maps of the outbreak created by A/Prof Alex Cook and his team at the Saw Swee Hock School of Public Health. Figures A and B show the clusters of confirmed Zika cases during the outbreak period, whereas C and D show the breeding percentage of Aedes aegypti among Aedes mosquito breeding sites in Singapore. Screen capture from the Lancet ID article on the Zika outbreak in Singapore.

The figure below shows the outbreak chart as well as the cumulative number of confirmed Zika human cases in Singapore between August and November 2016.

Screen capture from the Lancet ID article on the Zika outbreak in Singapore.

The bioinformatics work on 14 and 103 sequenced Zika viruses from captured mosquitoes and humans respectively, performed by Dr Sebastian Maurer-Stroh and histteam at A*STAR Bioinformatics Institute, also revealed interesting results. It suggested that Zika had been introduced into Singapore at least 3 times, with the primary outbreak lineage of Zika (accounting for the vast majority of cases) having “existed” since May 2016 – whether in a nearby country or in Singapore.

Phylogenetic tree  of Zika – screen capture from the Lancet ID article on the Zika outbreak in Singapore.

It is good that this important work has been published, and the Ministry of Health personnel, especially the lead author Dr Marc Ho, played a tremendous role in coordinating the work and compiling the manuscript.