The news was particularly shocking as there had not been any increase in reported cases of the disease for some time on the island.
The Cook Islands Ministry of Health is assuring the public that it will persist with surveillance and response activities to protect the people of the Cook Islands from the dengue threat.
A press release from MoH said their event, surveillance and response unit (ESR) was continuing to monitor information from American Samoa, the World Health Organisation and the Secretariat of the Pacific Community on a daily basis.
Dengue fever was circulating the Cook Islands last year, but the virus was contained by the Ministry of Health, with no further cases reported this year.
Dengue is caused by any of four viruses, types one to four, which are transmitted by the day-biting Aedes mosquitoes.
This is the same mosquito species which can also transmit the Chikungunya virus currently prevalent in the Cook Islands.
The mosquito can be recognised by white markings on its legs and a marking in the form of a lyre on the thorax.
Symptoms of dengue, which comes in four types, include high fever, severe headaches, severe pain behind the eyes, joint/muscle pain, rash, mild bleeding involving the nose of gums, and easy bruising.
Severe infections resulting from type four can result in haemorrhage, shock and death.
Dengue shares similar clinical signs with Chikungunya, although no deaths have been reported as a direct result of the latter.
The Ministry of Health is urging anyone who experiences any of these symptoms to immediately seek medical attention.
Infection Prevention Officer Charmaine Mageo is urging anyone experiencing body fever and aches to take Tylenol for the pain, as other treatments like Aspirin, Advil, Aleve or Motrin will increase the chances of bleeding.
Director of Community Services, Dr Neti Herman, is urging the public to take preventative measures to control the spread of mosquito-borne diseases.
This can be done through the destruction of mosquito breeding sites in homes, schools and the workplace, and by the use of personal protection including insect repellents.
This is especially important as the mosquito likes to breed in water collected in man-made materials like containers, tyres, cans or bottles, as well as coconut husks.
Information pamphlets will be distributed during the upcoming Tutaka cleanup campaign and these are also available at the airport for visitors upon arrival in the country.
Chikungunya prevention kits are available for any local accommodation providers and include an A3 poster, information booklets for staff and information cards for guests.
Cook Islands Tourism is encouraging hotels and resorts to provide guests with free insect repellent, candles or coils, which staff say will go a long way to ensuring the virus remains contained.
The Public Health team will continue to undertake surveillance, conduct awareness-raising campaigns and monitor the situation.
They would also like to advise all travellers, who are travelling within the Pacific region to take extra precautionary measures.