Dengue alert

The Department of Health has issued its Weekly Surveillance Report that shows dengue remains number two on the list of the most prevalent diseases in the country. The Department of Education promptly raised an alert against dengue hemorrhagic fever in all schools nationwide. Dengue fever is an infectious disease carried by mosquitoes and caused by any of four related dengue viruses. This disease used to be called "break-bone" fever because it sometimes causes severe joint and muscle pain that feels like bones are breaking, hence the name. Health experts have known about dengue fever for more than 200 years. One can get dengue virus infections from the bite of an infected Aedes mosquito. Mosquitoes become infected when they bite infected humans, and later transmit infection to other people they bite. Two main species of mosquito, Aedes aegypti and Aedes albopictus, have been responsible for all cases of dengue transmitted in this country. Dengue is not contagious from person to person.

A study once undertaken by the School of Education in Foundation University, Dumaguete City shows that the control of Aedes aegypti mosquito larvae is essential for the control of dengue fever (DF) and dengue haemorrhagic fever (DHF). Schools are potential mosquito breeding sites. Also, primary, secondary and tertiary school-age students are principal targets of the Aedes mosquitoes.

Dengue has become a steadily increasing health problem in the Philippines. Aedes control is largely based on source reduction. Therefore, knowledge of the types of mosquito breeding sites is a prerequisite for health personnel, schoolteachers and children and the community at large for the control of dengue. Teachers play an important role in facilitating of health promotion in dengue endemic areas. Students and teachers should be properly oriented to carry out personal, school and community mosquito and dengue control measures. Antecedent to this is an understanding of students’ perceptions about mosquito-related dengue control.

Attitudes and beliefs impact a person’s knowledge about mosquito control. For example, the belief that dengue is not a fatal or serious problem impairs a person from carrying out adequate mosquito control practices. Some people believe that mosquitoes within the home and outside are different. So it is believed that mosquitoes inside the house do not carry disease.

The best way to prevent dengue fever is to take special precautions to avoid contact with mosquitoes. Several dengue vaccines are being developed, but none is likely to be licensed by the Food and Drug Administration in the next few years. When outdoors in areas where dengue fever has been found, use a mosquito repellant containing DEET, picardin, or oil of lemon eucalyptus, dress in protective clothing-long-sleeved shirts, long pants, socks, and shoes. Because Aedes mosquitoes usually bite during the day, be sure to use precautions especially during early morning hours before daybreak and in the late afternoon before dark. Other precautions include keeping unscreened windows and doors closed, keeping window and door screens repaired and getting rid of areas where mosquitoes breed, such as standing water in flower pots, plastic and metal containers, coconut shells, birdbaths, discarded tires, water drums etc.

A medical research done during a dengue fever outbreak in Cebu in 1987 suggested that several public health measures can be implemented to prevent future dengue epidemics. Public health officials should undertake continuous active surveillance of dengue fever cases and mosquito breeding sites as a means of detecting dengue epidemics early so control measures may be instituted. Entomological studies have shown that Aedes aegypti indices are exceptionally high just before a dengue fever outbreak. The potential for mosquito-borne transmission is also enhanced by high population density. Aedes aegypti breeds near human dwellings, so environmental control and regular insecticide spraying in barangays is highly recommended.

However, mosquito spraying is only an effective short-term emergency measure when dengue cases reach epidemic proportions. Further study of mosquito resistance to DDT and other insecticides is useful. Intensive health education and proper training of housewives in the elimination of mosquito harborage is important and allows for community-based participation in control activities.

The future success of dengue control must be based on intensive surveillance of cases and mosquitoes, public cooperation in maintaining the environmental sanitation, and proper coordination of all dengue control activities. Mounting health education campaigns have effectively reduced dengue cases. If this kind of program continues in the next few years, we hope that dengue cases will continue to decrease.