No fever, but feeling weak? Could be dengue, say doctors .... symptoms include restlessness, vomiting, body ache and severe weakness

Prithvijit Mitra | TNN |  Nov 11, 2017, KOLKATA: Ballygunge Circular Road resident Sampat Devi Baid may have died of dengue after low-grade fever, but if you thought running a temperature is the first indication of the vector-borne disease, think again. Doctors have warned that they have been getting dengue patients who have not developed fever.

The phenomenon, which has affected several Kolkatans in the last few weeks, has both alarmed and puzzled doctors, as it makes detection — and subsequent treatment — more difficult. Timely detection is one of the most crucial factors in reducing mortality.

For patients who don't develop fever, the crucial symptoms to watch out for include restlessness, vomiting, body ache and severe weakness. Some may also have low-grade fever.

"We assume that high-grade fever is the first sign of dengue, but I have come across around six patients in the last two weeks who had very low fever," said Debashish Saha, consultant, AMRI Hospitals. "Their dominant symptoms were body ache and weakness. The absence of fever might lead doctors to rule out dengue. But it could be fatal," he warned. Fortunately, all his patients were advised to get tested for dengue, and they tested positive, he added.

Take the example of a patient who had come to see Saha as he was feeling weak for two weeks, without being feverish. "He said he was unable to handle the weakness. A blood test revealed he was dengue-positive. Had the disease been detected later, it could have proved fatal," Saha said.

Dengue, said microbiologist Irfaan Akhtar, is almost invariably associated with high fever. "If a patient has low-grade fever, it can be assumed that the immune system is not working well and he has had a repeat dengue attack," he said. "Fever is the immunological response to the virus, and it has to be there unless it is the same dengue strain striking a patient for the second time. In such cases, the body responds better and the fever could be absent," he explained.

He added that if the other classical dengue symptoms — body ache, weakness, vomiting and dehydration — are present, they will invariably be accompanied by fever.

Saha, however, felt it could be a new sub-type of the strain. "We have seen varied symptoms this season. Cases have often turned very serious within a short time. Conventional treatment hasn't been working. So, it could well be a new sub-type," he said.

Others felt low-grade fever or no fever at all could be due to a lower viral load. "The viral load is sometimes not heavy enough to raise the body temperature. But it can't happen due to a repeat dengue attack, for the same strain can never strike twice. A poor immunological response could also be the reason. But absence of fever is misleading. The lesson from this is that doctors should always recommend a blood test," said Dr Arindam Biswas, a general medicine consultant.