Communicable disease: dengue fever

Communicable disease: dengue feverCommunity Health Nursing NUR 4404 Michelle BoswellSpring 2011

purposeThis presentation will discuss various aspects of Dengue fever:

Signs and symptomsVectors Areas of prevalence At risk populationStages of infectionSpectrum of disease occurrenceControl of the diseaseTreatment

EpidemiologyDengue fever is can be caused by one of four different serotypesHaving one type of Dengue does not protect you from having another type in the futureMore than one infection can cause a greater risk of developing dengue hemorrhagic fever and dengue shock syndrome (Dengue fever, 2010)

VectorNies and McEwen tell us that vectors can be animals or arthropods, and they can transmit through biological and mechanical routes (p. 500, 2007). Dengue fever is transmitted between people by mosquitosIn rare cases, dengue fever can be transmitted from organ transplants or from mother to fetus (Dengue fever, 2010)

Incubation periodSymptoms usually begin 4-7 days after being bittenSymptoms then last 3-10 daysFor transmission to occur the mosquito must feed on a person during a 5- day period when large amounts of virus are in the blood; this period usually begins a little before the person become symptomatic Some people never have significant symptoms but can still infect mosquitoes. After entering the mosquito, the virus will need 8-12 days incubation before it can then be transmitted to another human. The mosquito is infected for the rest of its life. (Dengue fever, 2010)Emerging diseaseDengue occurs in some parts of the tropics and subtropics as an endemic, which means every year during rainy season The four types of Dengue emerged from monkeysThe virus independently jumped to humans in Africa and Southeast Asia between 100 and 800 years ago(Dengue fever, 2010)

incidencePrior to 1981, there were no known cases of Dengue in south or central AmericaThe first documented cases were not until the 1950s in the Philippines and Thailand (Dengue fever, 2010)The World Health Organization (WHO) estimates that 50 to 100 million infections occur yearly, including 500,000 DHF (Dengue hemorrhagic fever) cases and 22,000 deaths, mostly among children.

Areas of prevalence

Dengue in the u.s.Nearly all cases in the United States have been from travelers or immigrantsThe last continental outbreak was in south Texas in 2005 There was a small outbreak in Hawaii in 200126 states have a law that mandates reporting of Dengue fever casesStarting in 2009, all cases in the United States must be reported to the CDC (Dengue fever, 2010)

Signs and symptoms Undifferentiated fever (usually 2-7 days)Severe headache, retro-orbital eye pain, myalgias, arthralgias, a diffuse erythematous maculo-papular rash, and mild hemorrhagic manifestation. Subtle, minor epithelial hemorrhage, in the form of petechiae, are often found on the lower extremities (but may occur on buccal mucosa, hard and soft palates and or subconjunctivae as well), easy bruising on the skin, or the patient may have a positive tourniquet test. Leukopenia is frequently found and may be accompanied by varying degrees of thrombocytopenia. Children may also present with nausea and vomiting. Serological testing for anti-dengue IgM antibodies or molecular testing for dengue viral RNA or viral isolation can confirm the diagnosis, but these tests often provide only retrospective confirmation.(Dengue fever, 2010)

Signs and symptoms

Virus flow chart

Dengue Hemorrhagic feverDengue fever can become DHF quickly, which is life threatening.

Dengue Shock SyndromeDengue fever can quickly become DHF or DSS (Dengue shock syndrome) if not treated quicklySigns and symptoms of the disease process are noted below:Abdominal pain or tendernessPersistent vomitingClinical fluid accumulation (i.e., pleural effusion or ascites)Mucosal bleedingLethargy or restlessnessLiver enlargement (2cm)Increases in hematocrit concurrent with rapid decrease in platelet count

Clinical manifestations

TreatmentDengue feverDHF or DSSFluid replacement to maintain perfusion and urine output, decrease tachycardia, and improve blood pressureMethods to keep fever down, except aspirin

Timely and judicious use of supportive careAdministration of isotonic intravenous fluids or colloidsClose monitoring of vital signs and hemodynamic status, fluid balance, and hematologic parameterspreventionThere is no vaccine for dengue feverTravelers must be aware of risks in the areas they are visiting.There is a Travel Notices page within the CDC website that allows travelers to see current outbreaks in different countries http://wwwnc.cdc.gov/travel/notices.aspxStay away from mosquito-infested areasWear bug repellant, cover extremities, and sleep under a mosquito net if necessary

Local actionsLocal government health departments put out fliers reminding citizens to protect themselves against mosquitos, including not leaving containers of water around, because these are breeding grounds for mosquitosUsing mosquito nets and bug repellent are other ways to prevent the virus, but many citizens may not have access to these itemsSome countries efforts are listed on the following slides

Puerto RicoDengue is a major health burden in Puerto Rico. Televised public service announcements and posters, elementary and pre-school educational programs, and an exhibit at the Children's Museum in Old San Juan were evaluated separately using knowledge and practices surveys administered to children and their parents, surveys of house lots for larval container habitats, focus groups, and interviews with program organizers and participants. Exposure to the programs was associated with increased dengue-related knowledge, increased proportion of tires protected from rain, decreased proportion of water storage containers positive for mosquito larvae, and increased indoor use of aerosol insecticides. Exposure to the elementary school program was associated with slightly lower indices of residential mosquito infestation. The programs have resulted in high levels of awareness, some behavior change, and limited change in larval indices. Greater emphasis on the skills necessary for community members to keep containers free of mosquito larvae would increase program effectiveness. (Winch, 2002)

Dominican republicThe Ministries of Public Health and Social Assistance announced a RD$17 million campaign for dengue prevention and control throughout the country.

Deputy Minister of Public Health, Dr. Nelson Rodriguez Monegro said that over the next three months the health authorities will be involved in the process together with the municipalities, civil society bodies and community representatives.

He explained that the measures include overall management of dengue prevention and control, which will involve the entire Dominican population in order to reduce the incidence of the disease in the country.

He said that the components of the program include increased surveillance for the detection of fever, overall control by eliminating mosquitoes that spread dengue and eliminating breeding sites, and launching a massive educational campaign.

Monegro also cited efforts for improvement in the care of people who contract the disease and the involvement of local groups in actions to prevent and control dengue. (Dengue fever prevention, 2010)Sri lankaThe Ministry of Health is to commence its special dengue prevention program from Colombo The Ministry plans to carry out the dengue prevention program in two phases. In the first phase the Ministry plans to introduce an awareness program followed by a sanitization program in the second phase. The Health Ministry hopes to carry out its awareness program from house to house with the assistance of the Colombo Municipal Council (CMC) and several nurses unions. In the second phase of this process the Ministry will destroy all the places that promote the mosquito breeding in the Colombo municipality. The Health Ministry expects the public support for this program as the spreading of the dengue fever in the country has become a national crisis. Similar dengue prevention programs for outstations will be carried out in the coming weeks. (Dengue prevention programs, 2009)philippinesThe government has embarked on a nationwide information campaign in the wake of the rising incidence of dengue cases in the country.In a news briefing, President Benigno S. Aquino III said the drive is focused on cleanliness particularly in the light of a Department of Health report of a 50 percent increase in the incidence of the killer disease this year.During our meeting on Monday, Dr. Enrique Ona (DOH Secretary) mentioned there was a 50 percent increase in the incidence of dengue cases. He is now going around for an education campaign dealing with the cleanliness drive, the President said.The President said the educational drive involves public awareness and participation in cleaning the common breeding grounds of the Aedes aegypti mosquitoes such as unattended old tires, empty cans and bottles, gutters and the like.From January to July this year alone, the DOH reported 40,648 cases with a total of 328 deaths (Government launches, 2010)

Methods of researchDengue fever (2010). In Centers for disease control. Retrieved April 20, 2011, from http://www.cdc.gov/Dengue/

Dengue fever prevention program (n.d.). In real-estate-dominican.com. Retrieved April 21, 2011, from http://www.real-estate-dominican.com/medical-info/153-dengue-fever-prevention-program-2010.htmlDengue prevention programs to commence from Sri Lanka capital (2009, May 16). In Colombopage: Sri Lanka Internet Newspaper. Retrieved April 21, 2011, from http://www.colombopage.com/archive_091/May1242481165RA.html

Methods of researchGovernment launches nationwide dengue info drive (2010, August 25). In Philippines, Embassy of the Philippines. Retrieved April 21, 2011, from http://www.philippineembassy-usa.org/news/526/300/Gov-t-launches-nationwide-dengue-info-drive/d,phildet/

Nies, M. A., & McEwen, M. (2007). Community/Public health nursing (4th ed., p. 500). St. Louis, MO: Saunders Elsevier.

Winch, P., Leontsini, E., Rigau-Perez, J., Ruiz-Perez, M., Clark, G., & Gubler, D. (2002, October). Community-based dengue prevention programs in Puerto Rico: impact on knowledge, behavior, and residential mosquito infestation [Electronic version]. American Journal of Tropical Medicine and Hygiene, 67(4), 363-370.