To discuss about dengue fever in general; the host, the infectious agent, their types and life cycles and method of transmission To explain why this topic is very important for us, Malaysian, the Asian community To discuss the impact of this disease to our environment, community, socioeconomic And how we deal with it specifically and generally
CHAPTER 1: DENGUE FEVER IN GENERALi. DEFINITIONii. THE INFECTIOUS AGENTiii. THE HOST & CARRIERSiv. LIFE CYCLEv. CLINICAL PICTUREvi. HISTOPATHOLOGY
What is dengue fever? It is a fever associated with other significance of clinical manifestations caused by virus from mosquito bite
• Dengue fever is not contagious.• It cannot be spread directly from one person to another person.• The mosquito transmits the Aedes aegypti disease by biting an infected person and then biting someone else. Aedes albopictus Aedes larvae
What are the infectious agent?• Dengue Fever and dengue hemorrhagic fever are caused by any of the dengue family of viruses.• Infection with one virus does not protect a person against infection with another. This is due to 4 strains or serotypes of dengue virus namely • DEN-1 • DEN-2 • DEN-3 • DEN-4
The host: Unfortunately, human is the only hostCarriers: Mosquito, Aedes species. Aedes aegypti - yellow fever mosquito Bites man, carries chikungunya, dengue fever, heartworm, Murray Valley encephalitis, Ross River virus, West Nile virus, yellow fever Aedes albopictus - Asian tiger mosquito Bites man, carries Cache Valley virus, chikungunya, dengue fever, Eastern equine encephalitis, West Nile virus
How soon after exposure do symptoms appear?• The time between the bite of a mosquito carrying dengue virus and the start of symptoms averages 4 to 6 days, with a range of 3 to 14 days.• An infected person cannot spread the infection to other persons but can be a source of dengue virus for mosquitoes for about 6 days.
Are there many clinical types of dengue? YES.Classic picture is :• high fever with no localizing source of infection• a petechial rash with thrombocytopenia• relative leukopenia - low platelet and white blood cell count.Dengue hemorrhagic fever is:• General: Fever, bladder problem, constant headaches, severe dizziness and loss of appetite.• Hemorrhagic tendency• Thrombocytopenia• Evidence of plasma leakageDengue shock syndrome is defined as dengue hemorrhagic fever plus:• Weak rapid pulse,• Narrow pulse pressure (less than 20 mm Hg)• Cold, clammy skin and restlessness.
High fever - up to 105 Children get non-typical degrees Fahrenheit (40.56 symptoms Celsius ) Fever Severe headache Weakness Retro-orbital pain - pain Prostration - physically & behind the eye emotionally weak Severe joint pains Severe headache Muscle pains Severe muscle pain Muscle aches Slowed heart rate Swollen lymph nodes Enlarge lymph nodes General weakness Maculopapular rash Nausea Rash Vomiting
Dengue hemorrhagic fever is a severe, often fatal, complication of dengue fever.This is the most feared condition to us
The has been in use since 1975; all four criteria must be fulfilled: General: Fever, bladder problem, constant headaches, severe dizziness and loss of appetite. Hemorrhagic tendency (positive tourniquet test, spontaneous bruising, bleeding from mucosa, gingiva, injection sites, etc.; vomiting blood, or bloody diarrhea) Thrombocytopenia (<100,000 platelets per mm³ or estimated as less than 3 platelets per high power field) Evidence of plasma leakage (hematocrit more than 20% higher than expected, or drop in haematocrit of 20% or more from baseline following IV fluid, pleural effusion, ascites, hypoproteinemia)
The first is the febrile phase. This phase is defined by very high body temperature of 40-41°C, and obvious feverish facial flush, vomiting, abdominal pain or restlessness. The second is the plasma leakage phase. This phase starts at the end of the febrile phase, with the body temperature drops below 38°C. This phase lasts for 24 to 48 hours. This is also known as the critical phase. The third is the re-absorption or convalescent phase where plasma that leaks is reabsorbed. At this phase the patient may experience respiratory distress or difficulty in breathing.
•A TEM micrographshowing denguevirus virions(the cluster of darkdots near the center)