Dengue transmission through sex is theoretically possible, says the World Health Organisation.
But the organisation said there was no evidence at present to indicate epidemiological importance.
However Spanish health authorities confirmed a case of a man spreading dengue through sex, a world first for a virus which until recently was thought to be transmitted only by mosquitos.
In the Cook Islands this year, there have been 109 dengue cases reported in Rarotonga and four on Aitutaki.
All these cases are believed to have transmitted only by mosquitos.
Cook Islands health secretary Dr Josephine Herman said the ministry would continue to focus on vector control measures which includes identifying and destroying mosquito breeding and resting sites.
The ministry earlier stated that there have been no reported deaths attributed to dengue infection since the outbreak in January this year.
Rarotonga’s northern area remains the major hot spot for dengue cases and the ministry says other reported cases, including the recent ones, are coming from the eastern side of the island.
Health protection officers within Public Health carried out an aerial block spraying programme last month from Ooa to Pokoinu. These areas are identified as a hotspot for mosquito breeding grounds.
The unique case in Spain concerns a 41-year-old man from Madrid who contracted dengue after having sex with his male partner who picked up the virus from a mosquito bite during a trip to Cuba.
His dengue infection was confirmed in September and it puzzled doctors because he had not travelled to a country where the disease, which causes severe flu-like symptoms such as high fever and body aches, is common.
“His partner presented the same symptoms as him but lighter around ten days earlier, and he had previously visited Cuba and the Dominican Republic,” said Susana Jimenez of the Madrid region’s public health department.
“An analysis of their sperm was carried out and it revealed that not only did they have dengue but that it was exactly the same virus which circulates in Cuba.”
In an e-mail sent to AFP, Stockholm-based European Centre for Disease Prevention and Control (ECDC), which monitors health and disease in Europe, said this was “to our knowledge, the first sexual transmission of the dengue virus among men who have sex with men”.
Dengue is transmitted mainly by the Aedes Aegypti mosquito. It kills 10,000 people a year and infects over 100 million.
- Additional reporting from The Telegraph