Controlling Dengue

  • The disease is lethal, but can be beaten

Dengue has evolved as a global life-threatening public health concern, affecting around 2.5 billion people in over 100 countries. The number of cases reported by members states.increased from 2.2 million in 2010 to over 3.34 million in 2016. Although the full global burden of the disease is uncertain, the initiation of activities to record all dengue cases partly explains the sharp increase in the cases reported. Since 2010, Pakistan has had a dengue epidemic with 16,580 confirmed cases and 257 deaths in Lahore and nearly 5000 cases and 60 deaths in the rest of the country. The three provinces facing the epidemic are Khyber Pakhtunkhwa, Punjab and Sindh.

Dengue is a mosquito-borne viral infection. It causes flu-like illness, and occasionally develops into a potentially lethal complication called severe dengue. About half of the world’s population is now at risk. Dengue is found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas. Dengue virus is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Aedes albopictus. This mosquito also transmits chikungunya, yellow fever and zika. Dengue is widespread with local variations in risk influenced by rainfall, temperature and unplanned rapid urbanization. Despite government efforts, especially in Punjab, the high cost of prevention has limited the ability of Pakistan to control epidemics.

According to a recent report, overall 1,499 persons are confirmed with dengue infection so far. It may be noted here that the district magistrate had imposed Section 144 to deal with the outbreak in Islamabad on September 12, which seems useless. The district magistrate warned that any violation of the section would entail legal action. Under Section 144, tyre shop owners will not be allowed to put tyres in front of their shops and citizens will have to take precautionary measures while watering plants to prevent the spread.

  • Maintenance of the patient’s body fluid volume is critical to severe dengue care. Careful clinical detection and management of dengue patients can significantly reduce mortality rates from severe dengue. Vaccination should be considered as part of an integrated dengue prevention and control strategy

The primary preventative measure is the control of mosquito populations, because transmission requires mosquitoes as vectors. One practical and recommended environmental management strategy is to eliminate unnecessary container habitats that collect water (such as plastic jars, bottles, cans, tires, and buckets) in which Aedes aegypti can lay their eggs. This strategy is called source reduction. When container habitats are removed and water storage containers are covered with a fine mesh to prevent mosquitoes from getting inside them, mosquitoes have fewer opportunities to lay eggs and cannot develop through their aquatic life stages. Source reduction can be effective when performed regularly, especially when members of a community are mobilized and educated about vector control.

Environmental management initiatives can also include major changes in a community, such as installing water systems with direct connections to residences and replacing wells and other water-storage containers, which can be mosquito-breeding habitats. Smaller-scale environmental changes can also be effective. For example, mosquito populations can be reduced when all members of a community clear blocked gutters and street drains and keep their yards free of containers with standing water. Any open containers should be emptied and cleaned each week to eliminate mosquito eggs and larvae. These efforts can reduce the number of mosquitoes living in an area. Active monitoring and surveillance of vectors should be carried out to determine effectiveness of control interventions.

Community-based approaches must go hand in hand with educational initiatives that teach people about mosquito vectors and the risks of having mosquito-breeding habitats near their homes. Educational initiatives can encourage people to take an active role in participating in source reduction. Communities that understand the need to make behavioral changes are the most effective in controlling dengue. In addition, people can reduce the risk of mosquitoes entering their homes by using window and door screens or by keeping their doors and windows closed and using air conditioning to keep their homes cool. Aedes aegypti typically bite people during the day, so wearing long pants and long-sleeved shirts can reduce mosquito bites when spending time outdoors. In addition, mosquito repellents can be applied to exposed skin and clothing to lower the risk of mosquito bites. The Centers for Disease Control recommends mosquito repellents that contain DEET, picaridin, lemon eucalyptus oil, or IR3535 as the active ingredient. Sleeping under a mosquito net can also provide protection from being bitten, particularly in areas where people rest in the afternoon or in houses with infants. Other different methods also can be used to control dengue; like traps including ovitrap, with other chemical and biological controls.

There is no specific treatment for dengue fever. For severe dengue, medical care by physicians and nurses experienced with the effects and progression of the disease can save lives – decreasing mortality rates from more than 20 percent to less than one percent. Maintenance of the patient’s body fluid volume is critical to severe dengue care. Careful clinical detection and management of dengue patients can significantly reduce mortality rates from severe dengue. Vaccination should be considered as part of an integrated dengue prevention and control strategy.

There is an ongoing need to adhere to other disease preventive measures such as well-executed and sustained vector control. Individuals, whether vaccinated or not, must seek prompt medical care if dengue-like symptoms occur. The recent outbreak can more easily be tackled by getting back to the professionals who controlled dengue well during former CM Punjab Shahbaz Sharif’s era on war footing.

One of the major issues is the lack of management skills which is adding insult to injury. Additionally, the government must provide training on clinical management, diagnosis and vector control at the regional level with some of its collaborating centres, and formulate evidence-based strategies and policies. Moreover, new tools, including insecticide products and application technologies, must be developed.