Thursday, 13 June, 2024

Vigilance Against Dengue

Dr. Suman Raj Tamrakar

The outbreak of dengue has continued to pose threat to people in Nepal. This time, the epidemic broke out from the eastern part of Nepal some three months ago. The mosquito-borne tropical disease first affected Dharan badly. As of now, the epidemic has spread to over 56 districts, killing a few patients and infesting thousands of others. The earliest outbreak of this disease had been reported in Chitwan district in 2004.
The disease is caused by dengue virus. The symptoms of this infection appear within three to 14 days after causative virus enters the susceptible human body. Children, old people and those with diabetes, decreased immunity and taking steroids are easily prone to this infection. Dengue can be life-threatening for the people with chronic diseases such as diabetes and asthma. Importantly, any high grade fever as in dengue may cause abortion, preterm labour, prematurity leading to poor maternal and foetal morbidity and mortality.
The dengue viruses are of five types. But the dengue epidemic recorded this time in Nepal is mostly spread by female mosquitoes of the Aedes aegypti. Dengue is classified as simple or severe types. The characteristic symptoms of dengue are sudden-onset fever, headache (typically located behind the eyes), muscle and joint pains, and a characteristic skin rash.
Dengue is also known as ‘break bone fever’, as it is associated with muscle and joint pains. Besides, the affected persons might have vomiting, stomach pain and other gastro-intestinal symptoms. Generally, spontaneous recovery takes within two to seven days after the disappearance of the fever.
According to the dengue review reports, in a small proportion, the disease complicates into its severe form as dengue haemorrhagic fever, resulting in spontaneous bleeding, low levels of blood platelets and blood plasma leakage, or into dengue shock syndrome, where dangerously low blood pressure occurs.
The diagnosis of dengue is typically made clinically, on the basis of reported symptoms and physical examination. However, early disease can be difficult to differentiate from other viral infections. A probable diagnosis is based on the findings of fever plus two of the following: nausea and vomiting, rash, generalised pains, low white blood cell count, positive tourniquet test, or any warning sign.
Warning signs typically occur before the onset of severe dengue. The diagnosis should be considered in anyone who develops a fever within two weeks of being in the tropics or subtropics. Often, investigations are performed to exclude other conditions that cause similar symptoms, such as malaria, leptospirosis, viral haemorrhagic fever, typhoid fever, meningococcal disease, measles, influenza and Zika fever.
Laboratory investigations include complete blood cell count, liver function test and ultrasound may assist in the early identification of dengue shock syndrome. The diagnosis of dengue fever may be confirmed by microbiological laboratory testing.
A vaccine for dengue fever has been approved and is commercially available in a number of countries.
Mostly, the people infected with dengue virus are asymptomatic (80 per cent) or have only mild symptoms such as an uncomplicated fever. Others have more severe illness (5 per cent), and in a small proportion it is life-threatening. So, those suffering from the epidemic need not be panicked. Instead, immediate measures should be taken once suspected. If the epidemic is recognised and managed in time, mortality is less than one per cent.
As the epidemic has been reported in the Kathamandu Valley during the pre-Dashain, the movements of the valley dwellers may result in its further spread in different parts of the country if the situation is not controlled in time. Therefore, it is necessary for the government and other responsible agencies to raise public awareness about the epidemic through mobilising school children, health volunteers and transport companies.
Local FM radios, posters and banners can also be suitable means to disseminate the information in different local languages. The outbreak of dengue fever increases the need for blood products. So, blood donation campaigns should be intensified in coordination between Red Cross and other local NGOs. The use of mosquito net should be promoted. The primary method of controlling A. aegypti is through eliminating its habitats. This can be done by getting rid of open sources of water.
(Dr. Tamrakar is an associate professor at Kathmandu University School of Medical Sciences and senior obstetrician at Dhulikhel Hospital.)