Pakistan Medical Society Chairman Dr Masood Akhtar Sheikh while addressing the Dengue Community workshop By PMS in collaboration with Mother & child Rehabilitation society at Special Kids inn, Lahore said that Dengue infections have been reported in over 100 countries and are widespread in most tropical countries of the South Pacific, Asia, the Caribbean, the Americas, and Africa. The geographic spread of dengue infections is similar to that of malaria, but unlike malaria, dengue infections are often found in the urban areas of tropical nations, including Thailand, Singapore, Taiwan, Indonesia, Philippines, India, and Brazil. Globally, there are an estimated 50 to 100 million cases of dengue fever (DF) and several hundred thousand cases of dengue hemorrhagic fever (DHF) per year. Younger children and those with their first dengue infection have a milder illness than older children and adults. If they feel worse (e.g., develop vomiting and severe abdominal pain) in the first 24 hours after the fever declines, they should go immediately to the hospital for evaluation. There is no vaccine for preventing dengue.
The best preventive measure for residents living in areas infested with Ae. aegypti is to eliminate the places where the mosquito lays her eggs, primarily artificial containers that hold water. Items that collect rainwater or to store water (for example, plastic containers, drums, buckets, or used automobile tires) should be covered or properly discarded. Pet and animal watering containers and vases with fresh flowers should be emptied and cleaned (to remove eggs) at least once a week. This will eliminate the mosquito eggs and larvae and reduce the number of mosquitoes present in these areas.
Dr Masood Sheikh said that the emphasis for dengue prevention is on sustainable, community-based, integrated mosquito control, with limited reliance on insecticides (chemical larvicides, and adulticides). Preventing epidemic disease requires a coordinated community effort to increase awareness about dengue fever/DHF, how to recognize it, and how to control the mosquito that transmits it. Residents are responsible for keeping their yards and patios free of standing water where mosquitoes can be produced.
Dr Masood sheikh said that for the prevention following things are to be kept in mind.
Be aware of peak exposure times and places: Exposure to arthropod bites may be reduced if people modify their patterns of activity or behavior. Although mosquitoes may bite at any time of day, peak biting activity for vectors of some diseases (e.g., dengue,) is during daylight hours. Avoiding the outdoors or focusing preventive actions during peak hours may reduce risk.
Wear appropriate clothing: People can minimize areas of exposed skin by wearing long-sleeved shirts, long pants, boots, and hats. Tucking in shirts and wearing socks and closed shoes instead of sandals may reduce risk. Repellents or insecticides such as permethrin can be applied to clothing and gear for added protection
Bed nets: When accommodations are not adequately screened or air conditioned, bed nets are essential to provide protection and to reduce discomfort caused by biting insects. If bed nets do not reach the floor, they should be tucked under mattresses. Bed nets are most effective when they are treated with an insecticide or repellent such as permethrin. Pretreated, long-lasting bed nets can be purchased. The permethrin will be effective for several months if the bed net is not washed. (Long-lasting pretreated nets may be effective for much longer.)
Insecticides: Aerosol insecticides, vaporizing mats and mosquito coils can help to clear rooms or areas of mosquitoes; Insecticides should always be used with caution, avoiding direct inhalation of spray or smoke.
Product efficacy and duration of protection are also markedly affected by ambient temperature, amount of perspiration, exposure to water, abrasive removal, and other factors
Regardless of what product is used, if one start to get mosquito bites they should reapply the repellent according to the label instructions or leave the area with biting insects if possible.
Most repellents can be used on children >2 months of age.
Protect infants <2 months of age from biting mosquitoes by using an infant carrier draped with mosquito netting with an elastic edge for a tight fit.
Mode of Transmission
Transmission occurs from the bite of an infected Aedes aegypti (rarely Aedes albopictus) mosquito. Mosquitoes first become infected with DENV by feeding on the blood of a dengue-infected person. After the virus replicates for 8–12 days in the mosquito, the mosquito can transmit DENV to many other people.
Direct person-to-person transmission has not been documented. A few case reports have been published of transmission of DENV through exposure to: dengue-infected blood, organs, or other tissues from blood transfusions; solid organ or bone marrow transplants; needlestick injuries; and mucous membrane contact with dengue-infected blood.
Treatment
No specific therapeutic agents exist for dengue infections.
Encourage bed rest and maintenance of fluids to prevent dehydration.
Control fever with acetaminophen. Headache, back pain and muscle aching may be so severe as to require narcotics. Aspirin (acetylsalicylic acid), aspirin-containing drugs, and other nonsteroidal anti-inflammatory drugs (e.g., ibuprofen) should be avoided because of their anticoagulant properties. Aspirin and other salicylates should be especially avoided in children due to the association with Reye syndrome
Ask patients to watch for warning signs of DHF or DSS as fever declines 3–7 days after onset of symptoms. Instruct patients to go to the hospital if they have any of the following warning signs: abrupt change from fever to hypothermia, severe abdominal pain, persistent vomiting, bleeding, difficulties breathing, or altered mental status (e.g., irritability, confusion, lethargy).
Prompt and judicious administration of intravenous fluids in patients with DHF or DSS can improve outcomes. In patients with DHF or DSS, hospitalization with close monitoring of vital signs, fluid balance, and hematologic parameters (i.e., hematocrit, platelet count) is indicated, as well as additional supportive measures.