Dengue fever is the most important arthropod-borne viral illness with public health implications. In the 1950s, there were nine reporting countries; currently, the geographic dispersion encompasses more than 100 countries worldwide. Many of these people had not reported dengue fever in 20 years or more, and several had no known history of the disease.
According to the World Health Organization, more than 2.5 billion individuals are at risk of dengue infection. It was first identified in the 1950s and has since become a prominent cause of child death in a number of Asian and South American countries.
Each year, an estimated 400 million people are infected with dengue virus through mosquito bites. Around 100 million people become unwell. In Southeast Asia, the Western Pacific, the Eastern Mediterranean, the Americas, the Caribbean, and Africa, outbreaks have occurred.
Currently, dengue fever has been spreading widely in Dhaka city as well as all over the country. Moreover, according to recent statistics, only 63 facilities (20 public and 43 private) out of several hundred hospitals and clinics in Dhaka, the core of the outbreak, are currently designated to report dengue cases to the surveillance system.
To deal with the influx of patients, Bangladesh Shishu Hospital and Institute established a distinct dengue cell, and the 800-bed Dhaka North City Corporation (DNCC) Hospital was designated as a dengue-dedicated hospital.
To handle the increased number of infections and fatalities, the government has urged all medical colleges and public hospitals across the country to open specialized dengue wards and corners, and appreciation must be directed to the government for taking this initiative to overcome such hazardous situations.
Controlling mosquito populations is the key method for reducing dengue illnesses. Because dengue transmission requires insects as vectors, mosquito populations can be reduced to restrict the spread of dengue.
What can people who are at risk of dengue diseases do to help lower mosquito populations? Eliminating superfluous container habitats that collect water (such as plastic jars, bottles, cans, tires, and buckets) in which the mosquitoes can lay their eggs is one practical and recommended environmental management method.
This is known as source reduction. When container habitats are removed and water storage containers are closed with fine mesh to keep mosquitoes out, mosquitoes have fewer opportunities to lay eggs and cannot develop through their aquatic life stages.
Major changes in a community can also be part of environmental management measures, such as building water systems with direct connections to households and replacing wells and other water-storage containers, which can serve as mosquito breeding grounds.
Smaller-scale environmental changes can also have a big impact. Mosquito populations, for example, can be reduced if all members of a community clear blocked gutters and street drains and keep their yards free of containers holding standing water.
To eliminate mosquito eggs and larvae, any open containers should be emptied and cleaned once a week. These measures can help to lower the number of mosquitoes in a certain location.
Personal efforts to reduce mosquito contact
People can limit the chance of mosquitoes entering their houses by installing window and door screens, closing their doors and windows, and utilizing air conditioning to keep their homes cool. Because the mosquitoes bite individuals throughout the day, wearing long pants and long-sleeved shirts can help decrease mosquito bites when spending time outside.
Mosquito repellents can also be applied to exposed skin and clothing to reduce the risk of mosquito bites. The Centers for Disease Control recommends mosquito repellents with the active component DEET, picaridin, lemon eucalyptus oil, or IR3535.
Sleeping under a mosquito net can also protect you from being bitten, especially in locations where people rest in the afternoon or evening in houses with infants.
Mosquito control using chemicals
Chemical control of mosquito populations can be effective. Insecticides, for example, can be used to kill mosquito larvae or adult mosquitoes. Can insecticides be used broadly and routinely? Insecticides are advised for use in emergency settings during dengue epidemics or when there is an indication of an outbreak.
However, on a regular basis, sustainable, coordinated, community-based environmental measures are preferable over chemical methods for mosquito control, and limited reliance on these pesticides is desired.
Why are environmental management strategies preferred? One explanation is that mosquitoes can evolve pesticide resistance. Furthermore, insecticides are costly, and high amounts can be hazardous to humans and other animals. As a result, it is best to exercise caution when using these compounds.
Mahmodul Hasan Shesheir is a Research Assistant, BRAC James P Grant School of Public Health, BRAC University.
