Zika virus: epidemiology, vector and sexual transmission, neurological disorders and vector management- a review

Although mosquitoes are the primary vectors of Zika virus (ZIKV) and are considered to be responsible for its major outbreaks worldwide, sexual transmission is also agreat concern. Another major concern is the neurological disorders of ZIKV infection of pregnant mothers on the newly born babies. The ZIKV is an emerging Flavi virus of the Spondwenisero complex, a mosquito-borne zoonotic pathogen that causes dengue-like syndromes and is described as a mild, self-limiting febrile illness with no known fatalities. ZIKV remained confined to a narrow equatorial band in Africa and Asia until 2014 when it spread eastward, first to Oceania and then to South America. The virus is vectored by mosquitoes but other modes of transmission are also common. Sexual transmission is a unique characteristic of this virus and increased travel and commerce movements have facilitated the spread of ZIKV to different parts of the globe where the vectors are either absent or not established to transmit the virus locally. ZIKV was limited to isolated cases in Africa and Asia, until the 2015 Brazilian epidemics when it rapidly spread throughout the Americas. Mostly ZIKV infections are characterized by mild subclinical illness but the severe neurological manifestations like Guillain-Barre syndrome in adults and microcephaly with other neurological disorders in babies born to infected mothers are serious public health concerns. Unfortunately, neither an effective treatment nor a vaccine is available to treat the infected patients and the public health response is focused on vector population management and transmission prevention, particularly in pregnant women. Information on growing knowledge about ZIKV regarding the vectors, reservoirs, modes of transmission, neurological disorders, microcephaly, and vector management with possible potential synergy of co-infection with other co-circulating viruses is very crucial to develop management strategies. This paper presents a critical review of the available literature on epidemiology, vector and sexual transmission and neurological disorders of ZIK Valong with the vector management.