Dengue deaths are being reported almost every day but there is no way of knowing, in the absence of official figures, whether the situation is worse than in other years.
There have been nine known dengue deaths in the past 16 days, between September 27 and October 12, in the Kolkata, Bidhannagar and South Dum Dum municipal areas. The actual number could be more.
The state health department is not publishing figures of dengue infections and deaths. Neither is it sending them to the National Center for Vector Borne Diseases Control in Delhi.
Doctors and hospital officials have said most of the dengue patients who died this year were young, in their 20s.
The condition of many patients is suddenly turning critical and the situation is getting out of hand. The warning signals this dengue season are mild and doctors and family members are often unable to identify them.
The Telegraph spoke to doctors to find out what makes the current dengue outbreak different from the previous ones.
Sudden deterioration
According to doctors, dengue shock syndrome is getting difficult to identify this season, causing sudden deterioration in the condition of patients.
“We are seeing in many young dengue patients a condition called compensated shock. Which means, their conditions are apparently stable and all vital statistics are within the normal limits, but they are already in a state of dengue shock,” said Kausik Chaudhuri, pulmonolgist and nodal officer, dengue, at Infectious Diseases & Beleghata General Hospital.
“Relatives and some doctors are missing the warning signals thinking the patients are stable, which is causing delayed intervention.”
Chaudhuri said the warning signs include abdominal pain, vomiting, nausea and a slight reduction in urine output.
“In most of these cases (where the situation is suddenly turning serious), the blood pressure and sensorium are normal. So the warning signs are not picked up and that is delaying the treatment. The patient’s condition then deteriorates within a few hours,” he said.
“We need to identify the warning signs in time and immediately shift the patient to the ICU and start rapid fluid therapy. Timely intervention can control the criticality,” Chaudhuri said.
At the ID hospital, he said, 30 to 40 per cent of the critical patients displayed mild symptoms initially.
Liver involvement
Bhattacharya said more dengue patients now are having their liver impacted than in the previous outbreaks.
“This time, the involvement of liver is found in about 80 to 90 per cent of the patients admitted under me. Earlier, it used to be 50 to 60 per cent. This time there are severe manifestations like viral hepatitis. In a few cases, that is leading to liver failure,” Bhattacharya said.
Cytokine storm
Doctors said the sudden worsening of the condition is also related to a condition called the cytokine storm, which usually happens after five days of dengue fever.
“After a person is infected with the dengue virus, the antibodies the body generates will protect it from all four strains of the virus for three months. After that, the antibodies only provide protection from the strain that caused the infection,” said Chandramouli Bhattacharya, infectious disease specialist at Peerless Hospital.
“If the person is later infected with any other strain of the virus, the antibodies, rather than protecting the body from the infection, aggravates it, resulting in severe manifestation through immune-mediated phenomenon,” he said. “Conditions like dengue shock depends more on such aberrant immune response of the body.”c
Young patients have a hyper immune response and it works against the body, damaging vital organs, said Chaudhuri of ID hospital.