A 48-year old builder in Ahmedabad died on August 10 of what is suspected to be dengue haemorrhagic fever (DHF). A death audit is on but if confirmed, it would be the first death due to DHF in Ahmedabad this year. According to the WHO, a patient enters what is called the critical phase normally about 3-7 days after illness onset. During the 24-48 hours of critical phase, a small portion of patients may manifest sudden deterioration of symptoms. It is at this time, when the fever is dropping (below 38°C/100°F) in the patient, that warning signs associated with severe dengue can manifest. Severe dengue is a potentially fatal complication, due to plasma leaking, fluid accumulation, respiratory distress, severe bleeding, or organ impairment.
What makes dengue fatal and should you be concerned?
While a majority of dengue cases are non-fatal, about two per cent cases may become fatal. Mortality in terms of total positive dengue cases is less than one per cent. During onset, we never know which patients can turn serious or fatal. So, we must take precautions from the first day of symptoms itself. The supervision time is usually seven to 12 days. If an individual is fairly okay until the seventh day, one can safely assume that the case is non-fatal and will report an uneventful recovery. When uncomplicated dengue changes to dengue haemorrhagic fever (DHF) or dengue shock syndrome (DSS), then it can be fatal.
There is no treatment for dengue. We administer a broadly supportive treatment unlike malaria where we have anti-malarial drugs which can be administered from day one and reduce the chances of the disease turning fatal. Healthy individuals and comorbid individuals are more or less equally susceptible to slipping into severe disease, although those with multiple comorbidities are more prone to severe disease. We do find fatality in individuals with no prior comorbid conditions but elderly and paediatric individuals are more prone to developing severe complications.
When is the crucial period when DSS/DHF can set in and what are the signs you should look out for?
It can happen anytime in the 7-12 day observation period but generally the symptoms of severe disease progression show up between the second and fourth days, with a complex case behaving in a different manner compared to a non-severe case. Complications include low blood pressure and organ failures of the liver, kidney and brain, which can cause internal bleeding. When these symptoms show up, we can say the patient is going towards DHF or DSS.
The WHO has listed several warning signs like severe abdominal pain, persistent vomiting, rapid breathing, bleeding gums or nose, fatigue, restlessness, liver enlargement and blood in vomit or stool.
If patients manifest these symptoms during the critical phase, close observation for the next 24 – 48 hours is essential so that proper medical care can be provided, to avoid complications and risk of death. Close monitoring should also continue during the convalescent phase, according to the WHO.