Table 1: Factors That Might Have Contributed to Epidemics of Chikungunya Fever (13,20,36,27)

Can be Summarized as Follows:

Biological and genetic

Non-immune human populations

Genetic adaption in virus to A. albopictus during epidemic5

Ecological

East Africa drought that promoted standing water and disease transmission6

Warm European summer with high abundance of vector3

Physical environment

Artificial vector-breeding sites (household water-stores, manholes, used tyres)

Social, political, and economic

International and domestic travel

Delayed identifi ation and control of initial outbreaks

Previous introduction of exotic A. albopictus to Indian Ocean islands and Italy

Table 2: Case Definitions (62,91):

Suspected Case:

An acute illness characterized by sudden onset of fever with several of the following symptoms: Joint pain, headache,

backache, photo phobia, arthralgia, rashes.

Probable Case:

Above features and;

Positive serology either when single serum sample was taken during acute onset phase;

or during the convalescence.

Confirmed Case:

A confirmation can be done by any of the following method:

1. Four fold HI antibody difference in paired sera.

2. Detection of IgM antibodies against CHIKV.

3. Virus isolation from serum.

4. Detection of CHIKV nucleic acid in sera by RT-PCR.