As mosquito-borne virus Zika threatens to spread during the Pacific tropical cyclone season, volunteers may want to take heed of new research suggesting insect repellent could make the problem worse.
The study, published in the Journal of the Royal Society Interface, looked at the idea of incomplete personal protection having "the counter intuitive effect of increasing disease burden at the population level, by increasing the biting intensity on the unprotected portion of the population".
In other words, when some people wear mozzie repellent and use mosquito nets, those who don't are bitten more ferociously and have a higher chance of contracting a mosquito-borne disease like Zika.
The researchers, at the Gertner Institute for Epidemiology and Health Policy Research in Israel and McMaster University in Canada developed a virtual model analysis to run the numbers on the impact of only part of a group protecting themselves from mosquitoes.
"The model analysis revealed that partial coverage with popular personal protection techniques can realistically lead to a substantial increase in the reproductive number," the report said.
The report said more research needed to be done, and currently, the best way to avoid mosquito-borne disease is to use insect repellent, mozzie nets and other ways of avoiding bites.
In Zika-prone countries, meanwhile, a new report by the Centers for Disease Control and Prevention found there were 14 new suspected cases of sexually transmitted Zika virus.
The centre said it was waiting on test results for confirmation but advised safe sex practices for those who had visited a Zika-prone region.