No info now on how dengue progresses to haemorrhage or shock syndrome

After the first dengue fever case was reported in Kerala from Kottayam in 1997, the State has had regular annual epidemics of dengue during the southwest monsoon, especially from 2001.

All four serotypes of the virus circulate in the community. The severity of the situation is heightened by the fact that the primary vector responsible for the rapid spread of dengue in Kerala is Aedes albopictus, a mosquito which breeds in huge numbers in the wild and is virtually impossible to control.

Yet, apart from launching fire-fighting responses after every outbreak, there has never been any serious attempt by the State to invest in basic dengue research or the assessment of dengue mortality, which alone will help the State prime its dengue response.

The Integrated Disease Surveillance Project’s (IDSP) reporting system is still confined to collection of numbers. The system just generates the numbers of those affected by an infectious disease and the list of fatalities. The Health Department has no information — past or current — on what proportion of the dengue-affected population in the State develops dengue haemorrhagic fever (DHF) or dengue shock syndrome (DSS).

Need of the hour

With the dengue virus growing more aggressive in virulence and magnitude with every outbreak, it is becoming clear that a war against dengue can only be fought on the basis of science; by paying more attention to the documentation and analysis of dengue epidemics.

For the first time, the Health Department has now issued a directive to all district health administrations to set up technical committees to do a detailed auditing of every dengue and fever-related fatalities, by going through case sheets and medical documents in hospitals.

“After each epidemic, the department just moves on to other activities. There are no scientific reviews or assessment on how the epidemic was managed, whether all fever deaths were due to dengue. It is important to know what percentage of the population went into DHF or DSS because it helps us anticipate the severity of the epidemic in future,” a public health expert said.

Symptoms of other infectious disease such as leptospirosis might overlap those of dengue fever. During a dengue epidemic, most fever cases would be classified as dengue but it is important to study the suspected dengue cases to ascertain if there are other concurrent infections.

“Mortality data is the fundamental requirement in any epidemiology studies. The IDSP reports show that there have been nearly 100 suspected dengue deaths this season. Dengue has been confirmed as the cause of death in only 13 cases, which alone will figure in the official stats. If not all, at least a few of these suspected deaths from both government and private hospitals should be taken up in every district for a detailed mortality analysis,” he said.

Health Department officials admit that lack of medical auditing of deaths is a serious systemic flaw. “In hospitals the cause of death might be just recorded as dengue. It is difficult for the Health Department staff to access case sheets and records from hospitals, without which we will not know how the disease progressed,” a Health official said.