Chikungunya Fever Dr.Madhusudan.S

DIAGNOSIS TREATMENT PROGNOSIS

Clinical Diagnosis Chikungunya fever is suspected when a child, presents with fever, rash and joint symptoms more so during an epidemic.

Chikungunya in Children Less likely to have joint symptoms Even when present – milder , shorter duration. High fever, febrile convulsions G.I.Symptoms – vomiting,pain abdomen,constipation. Lymphadenopathy – more common

Mild haemorrhagic symptoms – epistaxis, petechial rash, positive tourniquet test.

Differential Diagnosis O’nyongnyong, Mayaro, Semliki forest. Not found in INDIA Ross River,Sindbis, West Nile, Barmah forest

Rubella,Parvovirus B19, Sixth disease,mumps, Hepatitis A & B, Lymphadenopathy, Salivary, extra salivary Tender hepatomegaly Epstein Barr Virus Gen lymphadenopathy & hepatosplenomegaly. Leptospirosis Cough,chestpain,icterus,lymphadenopathy,hepatomegaly,splenomegaly. Epidemic/endemic typhus Scrub typhus Not seen in INDIA G.I/Resp/rash(13%) Eschar/cough/G.I.

Enteric fever Relapsing Fever (tick borne) Pain abd,diarrhoea, Constipation, Hepatosplenomegaly G.I./Rash(18%) Henoch Schonlien purpura. Serum sickness Drug induced eruptions RF with E.marginatum. Palpable purpura,G.I, Renal(hematuria,HTN) Urticaria,drug exposure. Intensely pruritic. Carditis,chorea,scnodule

Dengue-The closest imitator Found in the same areas Dual infections reported in some cases Overlapping clinical features Children – greater incidence of haemorrhagic symptoms than adults

DENGUE CHIKUNGUNYA Endemic Sporadic explosive outbursts,vanishes & reappears. Altered taste, post-illness bradycardia and depression,asthenia Rash,conjunctival injection,arthralgia, myalgia Shock,hemorrhagic symptoms Prolonged joint pains

Laboratory Diagnosis IgG Vir IgM m-yrs 3-5wks 4 2 months 2-3 days

Demonstration of the virus Gold standard & most specific Culture-vero cells -C6/36 Aedes albopictus cells Intracerebral inoculation in newborn mice PCR

Demonstration of the antibodies Diagnostic test of choice: IgM ab capture ELISA IgG ab indicate past infection and without four fold rise of ab titre do not implicate the disease.

Principle of ELISA ligand Ag AB Anti AB Enz

Other Investigations CBC-Leucopenia Thrombocytopenia ^AST,ESR,CRP Chronic joint symptoms-synovial fluid Dec viscosity, poor mucin clot formation, WBC-2000-5000/mm3

TREATMENT-SUPPORTIVE Bedrest during fever Antipyretics and tepid sponging Analgesics and mild sedation Aspirin avoided-bleeding/Reye’s Syndrome Arthtritis-continued NSAID,movements,mild joint exercises Children-lose excessive fluids-ORS Break transmission cycle.

ROLE OF CHLOROQUINE 12%-Chr joint symptoms-partial response to NSAIDS. Study in France-10 patients 250mg/day for 20 weeks 7/10-patient 5/10 doctor Further studies needed

PROGNOSIS Most recover in few weeks 12%months to years Pregnancy-fever may cause abortions,preterm labour,fetal distress. Infants-90%-recover without sequelae

“Thankfully, the disease has proved so mild ; had it been different , this city, the home to half a million human beings would have become one vast charnel house with nobody to bury the dead and few to save the living” James Mellis, Calcutta epidemic 1963-64