Negative results for suspected dengue fever

Two cases under investigation recently for dengue fever have tested negative for the disease, according to Dr. Kiran Kumar, medical officer for health.

The patients presented with flu-like symptoms in November and their doctors had them tested for dengue fever, among other diseases.

For both patients the initial blood test came back negative, Dr. Kumar said. Test results take seven to 10 days because samples have to be sent overseas.

In the case of a negative result, the usual protocol is to retest the patient, as the antibodies being checked for may not have yet shown up, he explained.

‘The second test can be performed up to two to three weeks later. If that test is negative, then it is not a case of dengue,’ he said.

One patient has already been retested and received a second negative result. In the other case, the patient has been off-island so has yet to be rechecked, though Dr. Kumar believes the chances of a positive are very low.

‘One week had already lapsed after the onset of symptoms, by which time some antibodies might have formed. But this is only one of the diseases for which the doctor has been testing,’ he said.

Last month a local case of dengue fever was confirmed (Caymanian Compass, 12 December), the first such occurrence in years. Dengue fever is not endemic to the Cayman Islands, Dr. Kumar explained.

He said local transmission most likely took place when a returning resident or visitor who contracted the disease from a dengue-endemic country was bitten by a mosquito on the Islands which then bit a healthy person here, transmitting the disease.

The original infected person might only have had mild symptoms and may not have been diagnosed.

Mr. Kumar explained that in each year from 2002 to 2005, only one imported case of the disease was confirmed.

The symptoms of dengue fever are high fever, severe headache, backache, joint pains, nausea and vomiting, eye pain and rash.

No vaccine or specific medication is available to treat dengue fever, and patients are usually given pain medications. People normally recover from the illness within one to two weeks.