Infectious diseases are indeed a lifelong threat to everyone irrespective of age, sex, lifestyle and socio-economic status. The infectious diseases have persisted among the prominent causes of death globally. Recently, re-emergence of Chikungunya viral infection harmed many in Asian and African countries. Chikungunya was considered as a major threat in developing and under-developed countries; the recent epidemiological outbreak of Chikungunya in La Reunion urges the global researchers to develop effective vaccine against this viral disease. In this review, Chikungunya, pathogenesis and epidemiology were briefly described.

The unprecedented resurgence and geographical expansion of arboviral infections such as dengue, Chikungunya, yellow fever, and Zika have a significant impact on human health and pose a serious threat to public health globally in recent years. Zika virus is a Flavivirus and is transmitted to humans through an infected mosquito bite. The Zika virus has been identified in many countries in Africa, Asia, and Pacific islands and sporadic human cases have been reported since 1947. The non-specific clinical symptoms of Zika fever are often misdiagnosed with other arboviral infections, especially dengue and chikungunya. Till now, there is no vaccine or specific antiviral treatment for Zika infection. The recent emergence of Zika is alarming and highlights the need for arboviral research to develop an effective treatment. Here in this review, we discussed the epidemiology of Zika, which has re-emerged in the recent decade and caused international concern.

A number of re-emerging and emerging infectious diseases including chikungunya, West Nile, yellow fever, Zika, dengue, Japanese encephalitis, and others have increased in recent years, which threaten the public health across the globe. Chikungunya is a neglected re-emerging arboviral infection caused by chikungunya virus. Arboviral infections such as chikungunya, Zika and dengue have similar epidemiology, transmission cycles and clinical symptoms, which makes it difficult to diagnose these three infections. Moreover, there is no commercial vaccine or licensed therapy available for chikungunya infection, thus causing severe burden worldwide. Vector control may reduce the disease risk; however, this remains a challenge due to many factors including, but not limited to, evolution of insecticide resistance in mosquitoes, gaps in vector control tools, urbanization, environmental and demographic changes. Effective integrated vector control strategies and surveillance measures along with affordable vaccine development or anti-viral therapy are essential to control the infection. In this review, we discuss the epidemiology of mosquito-borne infection chikungunya which has re-emerged as an international concern in recent decades.

Objective: To obtain luteolin and apigenin rich fraction from the ethanolic extract of Cynodon dactylon (L.) (C. dactylon) Pers and evaluate the fraction's cytotoxicity and anti-Chikungunya potential using Vero cells. Methods: The ethanolic extract of C. dactylon was subjected to silica gel column chromatography to obtain anti-chikungunya virus (CHIKV) fraction. Reverse phase-HPLC and GC-MS studies were carried out to identify the major phytochemicals in the fraction using phytochemical standards. Cytotoxicity and the potential of the fraction against CHIKV were evaluated in vitro using Vero cells. Reduction in viral replication was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR) after treating the viral infected Vero cells with the fraction. Results: Reverse Phase-HPLC and GC-MS studies confirmed the presence of flavonoids, luteolin and apigenin as major phytochemicals in the anti-CHIKV ethanolic fraction of C. dactylon. The fraction was found to exhibit potent viral inhibitory activity (about 98%) at the concentration of 50 μg/mL as observed by reduction in cytopathic effect, and the cytotoxic concentration of the fraction was found to be 250 μg/mL. RT-PCR analyses indicated that the reduction in viral mRNA synthesis in fraction treated infected cells was much higher than the viral infected control cells. Conclusions: Luteolin and apigenin rich ethanolic fraction from C. dactylon can be utilized as a potential therapeutic agent against CHIKV infection as the fraction does not show cytotoxicity while inhibiting the virus.