Chikungunya virus; Review of epidemiology and outbreak in Pakistan

Abstract

Chikungunya virus (CHIKV) is mosquito-borne, alpha virus. It causes acute fever and acute and chronic musculoskeletal pain in humans. CHIKV has spread to 22 countries including Pakistan resulting in hundreds of thousands of death across the world. International travel stands out as one of the major risk factors for rapid global spread of the disease. CHIKV can be highly debilitating and large epidemic have severe economic consequences. Reemergence of CHIKV is serious public health concern. In the past 10 years, after decades of infrequent, specific outbreaks, the virus has caused major epidemic outbreaks in Africa, Asia, the India Ocean, and more recently the Caribbean and Americas. Chikungunya virus represents a substantial health burden to affected population, with symptoms that include severe joint and muscle pain, rashes, and fever, as well as prolonged periods of disability in some patients. Entry of virus into tissues causes infiltration of innate immune cells, monocytes, macrophages, neutrophils, natural killer cells and adaptive immune cells. Macrophages bearing the replicating virus, in turn, secrete pro-inflammatory cytokines IL-1B, TNF-a, IL-17. Together, this pro-inflammatory milieu induces osteoclastogenesis, bone loss, and erosion. Understanding the mechanisms of host immune responses is essential for the development of diagnosis, treatments and vaccines. Viral culture and isolation from blood cells of infected patients are the Gold standards for diagnosis. Early diagnosis of CHIKV is possible by nucleic acid detection techniques. Thus there is urgent need for continued research into the epidemiology, pathology, prevention and treatment of this disease. In this article, we have provided and update on Chikungunya virus with its recent epidemiology, molecular virology and antiviral therapies and vaccines.