EPIDEMIOLOGY OF CHIKUNGUNYA Definition: The study of the distribution and the determinants of health related states or events in specified population and the application of this study to the control of health problems

EPIDEMIOLOGICAL PYRAMID ► It includes host environment Agent

VECTOR AND MODE OF TRANSMISSION ► It’s a vector borne disease ► Vector is mosquito belonging to “AEDES” genus ► Other diseases caused by Aedes are ► DENGUE HAEMORRHAGIC FEVER ► YELLOW FEVER ► RIFT VALLEY FEVER

DESCRIPTION ABOUT AEDES ► Important members causing chickungunya are ► Aedes aegypti ► Aedes albopictus ► Aedes africanus ► Aedes furcifer ► Aedes taylori ► Aedes cordelliri

Aedes aegypti

Aedes mosquito ► Abundantly seen in india ► Called “TIGER MOSQUITO” (white stripes on the black body) ► Favourable climate tropical 27*c ► Life span of adult mosquito -15 days ► Habitat –mainly indoor-living room,offices, bussiness places, in isolated containers

Breeding habits Artificial accumulation of water in: ► Broken bottles ► Discarded tins ► Fire brackets ► Flower pots ► Coconut shells ► Earthen pots ► Tree holes ► Rubber containers ► Plastic containers

Breeding places of mosquito

Biting habits ► Only the female mosquito bites ► Bites mainly in day time ► Bites humans and animal ► Powerful bites / fearless bites ► Bites 3 to 4 times for a satisfactory meal

Resting habits Flying habits ► Rests in dark corners, walls, umbrellas, book shelves, coolers, bed covers. ► Flies around 100 mts from breeding places ► This factor helps in its eradication ► Transported to long distances by aero planes, ship, train.

Life cycle

MODE OF TRANSMISSION ► Only the female Aedes bites(blood meal) ► Transmission cycle: Man ► Becomes infective after ten days of bite & remains life long infective Mosquito

In Africa ► Viruses transmitted in Savanna & forests of Africa by Aedes africanus,Aedes furcifer ► Vertebrate portion of the cycle is provided by non human primates like monkeys & Baboons which amplify and maintain virus circulation

In Asia ► Virus is primarily transmitted by Aedes aegypti and to a lesser extent by Aedes albopictus in urban areas. ► Although Asian monkeys develop significant viraemia after inoculation. But they never have been shown to participate in maintenance or amplification of the virus

GLOBAL OUTBREAK YearPlace No.of Cases 1952TANZANIA (IN AFRICA) _ BANGKOK & THAILAND _ 2005 DEC- APRIL 06 REUNION ISLAND 2,25,000 9 TH JAN – 10 TH MARCH 06 MAYOTTE2833 WHO WHO

INDIAN OUTBREAK YEARPLACE NO.OF CASES SOURCE 1963CALCUTTALakhs 200 death ICMR Bulletin May MADRASlakhs IJMR MAHARASH TRA Small outbreaks Dec AP2,00,000 Wikipedia May5th Dec Karnataka78,000 Wikipedia May5th-06

Present epidemic in south India ► Mainly affected states are ► Karnataka, Maharashtra, AP ► Recent update on JULY 5 th 2006 DISTRICT NO. OF CASES GULBARGA55000 BIDAR42000 TUMKUR33000 CHITRADURGA20000 BANGALORE RURAL 8000 BANGALORE URBAN *wikipedia pandemic chikungunya