Via the Singapore Ministry of Health: Joint MOH-NEA Statement (3 Sep). Excerpt and then a comment:
As of 12pm, 3 September, MOH has confirmed 26 new cases of locally transmitted Zika virus infection in Singapore. Of these, 24 cases are linked to the Aljunied Crescent/ Sims Drive/ Kallang Way/ Paya Lebar Way cluster. Two cases have no known links to any existing cluster.
2. The National Public Health Laboratory has worked with A*STAR’s Bioinformatics Institute to complete the sequencing analysis of the Zika virus found in two patients from the Aljunied Crescent/ Sims Drive cluster. The analysis found that the virus belongs to the Asian lineage and likely evolved from the strain that was already circulating in Southeast Asia. The virus from these two patients was not imported from South America. The research team will release more details shortly.
Vector Control Update
3. NEA has been continuing with vector control operations to control the Aedes mosquito population in Aljunied Crescent / Sims Drive / Paya Lebar Way / Kallang Way. As of 2 September, 57 breeding habitats – comprising 32 in homes and 25 in common areas/other premises – have been detected and destroyed. NEA officers and grassroots volunteers are also continuing with outreach in Paya Lebar Way and Kallang Way.
4. NEA has also conducted vector control operations and outreach efforts in Bedok North Avenue. As of 2 September, 26 breeding habitats – comprising 17 in homes and 9 in common areas/other premises – have been detected and destroyed. Mosquito control measures are ongoing. NEA officers are continuing with outreach in this cluster as well.
5. In these two cluster areas, indoor spraying of insecticides, outdoor fogging, and oiling and flushing of drains are continuing. In such areas with active transmission, outdoor fogging and indoor spraying and misting are both necessary because there may be infected adult mosquitoes in both outdoor and indoor areas that need to be destroyed before they bite and infect more people. These methods are, however, only effective if the insecticide has direct contact with the mosquitoes, and thus have to be repeated frequently as new batches of mosquitoes will continue to emerge until all breeding habitats are found and removed. Hence, routine fogging is not a sustainable vector control measure – source reduction is still a more effective and sustainable strategy.
I'm looking forward to the promised details of the strain's lineage. My understanding is that Zika in the Americas is the Asian strain that evolved as the virus hopped from Africa to southeast Asia to the Pacific. If I'm mistaken, someone please correct me.