Tuesday 30th October, 2007 Posted: 17:07 CIT (22:07 GMT)
There are now 20 reported dengue fever cases in the Cayman Islands.
There is one confirmed case, one negative case and 18 awaiting results.
Seven of the suspect patients have no recent travel history to countries with dengue fever, which means the Aedes aegypti mosquito could be spreading the dangerous tropical disease locally.
Out of the 20 reported cases, three of the patients tested negative and will have to be retested.
“It takes a minimum of five to seven days after symptoms develop for the test to detect fever,” said Medical Officer of Health Dr. Kiran Kumar. “As a result all negative tests need to be followed by a second round of tests.”
Although dengue fever is not endemic to the Cayman Islands, the Aedes aegypti mosquito is present on Grand Cayman and its population is estimated to have surged by 1,300 per cent in the aftermath of Hurricane Ivan.
However, recent samples indicate populations may be down due to spraying and other targeted programmes, said Bill Petrie, director of the Mosquito Research and Control Unit.
Since first receiving confirmation of a dengue fever case in Grand Cayman 15 October, the MRCU has been targeting both areas where Aedes aegypti numbers are known to be high and areas around the homes of patients.
The mosquito is thought to be most prevalent in areas of George Town – particularly Windsor Gardens – and parts of West Bay.
The mosquito – which mainly lives and breeds around residential areas – flies only relatively short distances. This means it is absolutely critical that residents upturn any standing water in and around their home for their own safety, Mr. Petrie said.
Dengue fever is manifested by a sudden onset of fever, with severe headache, muscle and joint pains and rashes.
The dengue rash is characteristically bright red petechia and usually appears first on the lower limbs and the chest – in some patients it spreads to cover most of the body. There may also be gastritis with some combination of associated abdominal pain, nausea, vomiting or diarrhea.
Some cases develop much milder symptoms, which can – when no rash is present – be misdiagnosed as influenza or other viral infection. Thus travellers from tropical areas may inadvertently pass on dengue in their home countries, having not been properly diagnosed at the height of their illness. Patients with dengue can only pass on the infection through mosquitoes or blood products while they are still febrile.
The classic dengue fever lasts about six to seven days, with a smaller peak of fever at the trailing end of the disease. Clinically, the platelet count will drop until the patient’s temperature is normal.
Cases of DHF also show higher fever, haemorrhagic phenomena, thrombocytopenia, and haemoconcentration. A small proportion of cases lead to dengue shock syndrome, which has a high mortality rate