Experts discuss dengue, Zika
AHEALTH symposium hosted by the Pasteur Institute on containing and predicting dengue fever reflected on mixed results yesterday, while some experts took the opportunity to theorise on whether another headline-grabbing mosquito-borne virus – Zika – may already be present in the Kingdom.
Tuseo Luciano, WHO malaria program director in Cambodia, said that while “significant progress has been made . . . to detect, assess, report, and respond to dengue”, not as much progress has been made in the past few years as originally anticipated.
Pasteur researcher Julia Ledien presented an algorithm that had some success in predicting major outbreaks, and has steadily improved its accuracy as it gathers more data each year. The program inputs diagnostic data, which is then referenced against past dengue outbreaks in order to predict the future behaviour of the virus. “The most useful early warning is one that can predict a major outbreak,” Ledien said.
In 2015, the algorithm correctly predicted the behaviour of dengue in seven out of eight provinces. In Kratie, it predicted a major outbreak 11 weeks in advance. However, it still missed one outbreak, and others were predicted with very little time to make meaningful preparations.
Yves Bourny, the country director of the Malaria Consortium, said that even if a perfectly accurate early warning system were developed, the government may not take sufficient action to make a difference.
His colleague, senior technical officer John Hustedt, said that as Cambodia’s data collection improves, a more concrete plan that is both sustainable and self-sufficient needs to be made to address the issue of dengue. Hustedt also said Cambodia may simply not have the resources to combat major outbreaks, and should also focus on “routine prevention”.
One such preventative effort was a project in which the Malaria Consortium introduced guppy fish into private water storage containers to eat mosquito pupae. “There was quite a large difference between intervention and control zones,” Hustedt said, reporting that the rate of dengue infection was much lower due to the lower mosquito populations.
Meanwhile, Didier Fontenille, director of the Pasteur Institute, spoke about the Zika virus, claiming it was “still endemic in Cambodia”, with recorded cases as recently as 2015.
When asked directly if he thought there were people with Zika in Cambodia who have not been diagnosed, Fontenille replied “yes, I think so”, but noted the disease may go unnoticed because its symptoms are often mild.
Fontenille co-authored a report in November stating that Cambodia is at highrisk of a Zika outbreak in 2017, while other organisations questioned whether the country was prepared for such an event.
Arnaud Tarantola, also with Pasteur, wondered whether the seemingly recent “emergence” of Zika in the region was simply due to the fact that it’s only now being tested for.
The Malaria Consortium’s Hustedt also agreed that Zika is most likely already in the country, saying it was only logical given its presence in neighbouring nations and its historical existence in Cambodia.