CHIKUN GUNYA FEVER

INTRODUCTION  Caused by an Alpha Virus  Spread by bite of Aedes aegypti mosquito which usually bite during day light hours.  the name is derived from Swahili word meaning “that which bends up”  Chikungunya (CHIK) virus first isolated from the serum of a febrile human in Tanzania in  Chik virus has caused numerous out breaks in Africa and South Eastern Asia, involving hundreds and thousands of people.

CLINICAL FEATURES  Acute viral infection of abrupt onset.  Heralded by fever and severe arthralgia.  Followed by other constitutional symptoms like head ache, photo phobia, retrorbital pain, conjunctival infection and rash.  Lasting for period of 1 to 7 days.  Incubation period is usually 2 to 3 days.  Rarely can result in meningo – encephalitis

MANAGEMENT OF CASES  No specific treatment for Chikungunya  Illness is usually self limiting and will resolve with time.  Support care with rest is indicated.  Non asprin and non steroidal anti inflammatory drugs are recommended.  Unresolved arthritis refractory to NSAID, chloroqine 250mg is recommended

DIAGNOSIS Suspect Case  Characteristic triad of fever, rash and rheumatic manifestations Probable Case  As above with positive serology from single sample Confirmed Case  A probable case with any of the following  Four fold HI antibody difference in paired serum samples.  Detection of IgM antibodies.  Virus isolation from serum.  Detection of Chikungunya virus nucleic acid in sera by RT - PCR

LABORATORIES WORKING ON CHIKUNGUNYA 1.National Institute of Virology, Pune 2.National Institute of Communicable diseases, Delhi. 3.King Institute, Guindy, Chennai (Shortly).  Transport specimens to the laboratory at 2 – 8 o C as soon as possible  Do not freeze whole blood.  If more than 24 hrs delay is expected, serum should be sent

PREVENTION AND CONTROL  No vaccines or specific medication available.  Vector control is thus very important.  Elimination of breeding sites, or source reduction is an effective method of control.  Protection from mosquito bites by curtains / nets.  Fogging with insecticide spray  Intensification of surveillance.  Community sensitization by IEC activities.