COMMUNITIES

DENGUE

Maria Cristina L. Santiago, M.D., Health Services

Posted Thursday, 08-Sep-2005 11:03 AM

Date       :   6 September 2005

To          :   XAVIER COMMUNITY

From      :   Maria Cristina L. Santiago, M.D.

                  Health Services

Subject   :   DENGUE

      Dengue is a mosquito-borne infection which is caused by a virus. In recent years, it has become a major international public health concern. Dengue is found in tropical and sub-tropical regions around the world, predominantly in urban and semi-urban areas. There was a 15% increase this year compared to last year’s number of cases from January 1 to August 3. Metro Manila alone has 1,853 cases and 25 deaths.

Dengue Hemorrhagic Fever (DHF), a potentially lethal complication, was first recognized in the 1950s during the dengue epidemics in the Philippines and Thailand, but today DHF affects most Asian countries and has become a leading cause of hospitalization and death among children in several of them.

ETIOLOGY

•  Dengue Virus type 1, 2, 3, and 4: four distinct, but closely related, viruses

   that cause dengue.

•  recovery from infection by one provides lifelong immunity against that

   serotype but confers only partial and transient protection against

   subsequent infection by the other three

•  there is good evidence that sequential infection increases the risk of more

   serious disease resulting in DHF

EPIDEMIOLOGY

•  Source: infected persons

•  Mode of Transmission:

1. the virus circulates in the blood of infected humans for 2 - 7 days , at approximately the same time as they have fever
2. dengue viruses are transmitted to humans through the bites of infective day biting, low flying female mosquitoes, Aedes aegyti
3. mosquitoes generally acquire the virus while feeding on the blood of an infected person

•  Factors which favor spread of infection:

1. water stored within household or standing clean water in premises
2. high human population density (the more crowded the human population, the higher the infection rate)

•  Usual Places of Dissemination : hospitals and schools

•  Geographical: the spread of dengue is attributed to expanding geographic

    distribution of the four dengue viruses and of their mosquito vectors in

     tropical countries, mostly urban areas

INCUBATION PERIOD

•  3 - 10 days, usually 4 -6 days

SIGNS AND SYMPTOMS

•  FEVER: sudden onset, usually high grade ( 39 O C - 41 O C ), may last

   for 2 to 9 days

•  HEADACHE: mild to severe

•  WEAKNESS & FATIGUE

•  JOINT & MUSCLE PAIN

•  PAIN BEHIND THE EYES

•  SKIN RASHES: like the rashes of measles (maculopapular ) or red tiny

                           spots on the skin ( petechiae ) or generalized redness of

                           the extremities with intervening white spots

•  BLEEDING

1. nose
2. gums
3. skin : petechiae
4. stomach: coffee-colored vomitus / black stool

TREATMENT

•  NO SPECIFIC TREATMENT

•  maintenance of the circulating fluid volume is the central feature of DHF       case management

•  sufficient fluid intake is very important

•  Oral Rehydration Salt is recommended if the patient can tolerate oral 

     fluids

•  Antibiotics are not recommended

•  Paracetamol is the drug of choice to bring down fever

•  Aspirin, Ibuprofen, Mefenamic Acid should be avoided since they can

   increase the risk of bleeding

PREVENTION AND CONTROL

•  Aedes aegypti breeds primarily in man-made containers like earthenware

   jars, metal drums and concrete cisterns used for domestic water storage,    as well as discarded plastic food containers, used automobile tires and   

   other items that collect rainwater

•  at present, the only method of controlling or preventing dengue

  and DHF is to combat the vector mosquitoes

•  vector control is implemented using environmental management and

   chemical methods

•  proper solid waste disposal and improved water storage practices,

   including covering containers to prevent access by egg laying female

   mosquitoes are among methods that are encouraged through community-

   based programs

•  during outbreaks, emergency control measures may also include the

   application of insecticides as space sprays to kill adult mosquitoes using

   portable or truck-mounted machines or even aircraft

•  However, the killing effect is only transient , variable in its

   effectiveness because the aerosol droplets may not penetrate indoors to

   microhabitats where adult mosquitoes are sequestered, and the

   procedure is costly and operationally very demanding

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