S-111. Chikungunya- epidemiological and clinical aspects

The ongoing epidemic in the Indian Ocean region probably emerged first in Kenya before reaching the Comoros and Seychelles followed by Mauritius. For the first time, a substantial number of deaths were attributed, directly or indirectly, to chikungunya virus. Previously unreported complications, such as mother-to-child transmission, meningoencephalitis, myocarditis, hepatitis, and extensive dermal lesions were also encountered. The current outbreak, caused by the central/east African genotype, infected 1 400 000 cases during 2006 in India and is still causing outbreaks in Kerala and other states. Most often Chikungunya is a self-limiting febrile illness. Unlike dengue, hemorrhagic manifestations are relatively rare and as a rule shock is not observed. Arthralgia/arthritis appear to affect 73–80% of patients. Common hematologic abnormalities in the acute phase include lymphopenia and thrombocytopenia that may be associated with bleeding. Levels of hepatic enzymes are commonly increased, and viral loads are remarkably high. Viral persistence, which could explain long lasting clinical complications of CHIKV infection, has never been demonstrated. Although recovery may be uneventful, the incidence and severity of sequelae are more common in children, elderly and the persons with immune deficiency. Co-infections with Dengue, malaria and co-morbidities may play a significant role. Indiscriminate use of corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDS), especially aspirin and antibiotics can contribute to thrombocytopenia, gastrointestinal bleeding, nausea, vomiting and gastritis, dehydration, pre-renal acute renal failure, dyselectrolytemia, and sometimes hypoglycaemia; which can indirectly contribute to the mortality due to Chikungunya fever. Further research on mortality, co-infection and co-morbidities, drug interactions and reemergence are urgently needed.