DENGUE FEVER Niranjana J DENGUE FEVER Syn Breakbone

DENGUE FEVER Niranjana. J

DENGUE FEVER • Syn: Break-bone Fever / Dandy Fever Acute febrile illness characterized by • sudden onset of high fever • severe pain in the bones and joints, lymphadenopathy • relative bradycardia and a characteristic maculopapular reddish rash.

The Virology of Dengue Virus Group: Group IV Family: Flaviviridae Genus: Flavivirus Species: Dengue virus Man is the usual reservoir of infection Transmitted by female Aedes aegypti

Clinical Picture • Classic dengue fever -5 to 8 days. • • • Clinical picture – High fever (biphasic pattern) Myalgia Arthralgia Rash syndrome

Rash in Dengue Fever • The dengue rash-characteristically bright red petechiae • Appears first on the lower limbs and the chest, in some, spreads to cover most of the body. • It usually appears on the 3 rd to 5 th day. • It disappears as the temperature falls

Symptoms of Dengue • • • fever (saddle back fever) chills and rigor constant headaches bleeding from nose, mouth or gums orbital pain with painful movements of eyeballs • vomiting and diarrhoea

Pathology • • Endothelial swelling of small blood vessels Perivascular edema Mononuclear cell infiltration Second attack of dengue leads to a fulminant hemorrhagic disorder

Dengue cases reported from various states in India

Dengue Hemorrhagic Fever • Grade 1: Fever, constitutional symptoms • Grade 2: Grade 1 + spontaneous bleeding from gums, skin and GIT • Grade 3: Grade 2 + circulatory failure • Grade 4: Grade 2 + profound shock are together called as Dengue Shock Syndrome

WHO Definition of D. H. F • The WHO definition of DHF has been in use since 1975; all the four criteria must be fulfilled Criteria 1: • Fever • bladder problems • constant headaches • severe dizziness and loss of appetite. • myalgia and arthralgia are absent unlike classical dengue

Criteria 2: - • Hemorrhagic tendency (positive tourniquet test, spontaneous bruising, bleeding from mucosa, petechiae on forehead and extremities)

Criteria 3 & 4 • Thrombocytopenia (<100, 000 platelets per mm³ ) • Evidence of plasma leakage (hematocrit more than 20% higher than expected, or drop in haematocrit of 20% or more from baseline)

Dengue Shock Syndrome • Dengue 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 • Severe abdominal pain, protracted vomiting, marked change in temperature or change in mental status

Complications • Convulsions and respiratory failure • Death can occur on the 4 th or 5 th day due to gastrointestinal hemorrhage with hematemesis and melena • Circulatory failure • Non fatal cases recover rapidly

Laboratory Findings • Thrombocytopenia with relative leukopenia • Serologicals test -hemagglutination inhibition and complement fixing antibodies demonstrated 7 -14 days after the onset • ELISA test (for Ig. M antibodies) • PCR available to confirm the diagnosis

Treatment • Supportive therapy • Increased oral fluid intake • Platelet transfusion- if the platelet count drops below 20, 000 (rare cases) • Aspirin and NSAIDS must be avoided • Emerging evidence suggests that ribavirin inhibit dengue replication. In vivo studies, have not been done yet

Preventive Measures • • • Old tyres -dispose/cover Water storage-cover /add temphos Small container-clean up/bury/cover Every week have “Dry Day” Cleanup, drain, empty, or change all standing water

Personal Prevention: • • • Mosquito repellant - during daytime. Flywire / screening on doors and windows. Mosquito coils or vapor mats. Mosquito nets for children/ elderly Use combination of the above measures