Outbreak of Zika virus disease

Letter to editor: the publication on outbreak of zika virus disease is very interesting.[1] shrivastava et al. mentioned that “zika virus disease has emerged as a major public health concern and is expected to increase further in magnitude owing to the lack of immunity among the population in the affected regions.”[1] there are some concerns on the situation. first, the extension of the disease is already worldwide. silent infection is possible in many countries, especially in tropical asia.