Ebola virus - an Indian perspective.

Abstract

The current ongoing outbreak of Ebola Virus Disease (EVD) in West Africa is unprecedented in many ways. It is certainly one of the largest and deadliest outbreaks in recent times. It began in Guinea in late 2013 and spread to neighboring countries of Liberia and Sierre Leone. A total of 18,464 suspected, probable and confirmed (11,699) cases with 6841 deaths have been reported till 13th December 2014. Limited transmission is reported from United States of America (4 cases, 1 death) and Mali (8 cases, 6 deaths) whereas, Nigeria (20 cases, 8 deaths), Senegal (1 case, 0 deaths) and Spain (1 case, 0 deaths) have been declared free of EVD [1]. The outbreak has mounted exceptional concern, preparedness and response worldwide as it is dreaded as one of the most virulent disease causing high fatality in humans. It has no specific treatment or vaccine despite it being known since 1976 when it first appeared in Democratic Republic of the Congo (DRC) in two simultaneous outbreaks in Nzara, Sudan, and Yambuku, DRC. Until December 2013, a total of 23 outbreaks recorded 2388 human cases and 1590 deaths [2]. Formerly known as Ebola hemorrhagic fever, in the current outbreak EVD involved the health care workers and further weakened the already compromised health care system in the affected countries. Notably, experimental drugs were used in the treatment of humans. UN and other agencies and experts have accelerated the research, clinical trials and resolution of ethical concerns so that drugs and vaccines can be made available for prevention and control of EVD. Ebolavirus is one of three members of the Filoviridae family (filovirus), along with genus Marburgvirus and Cuevavirus. There are five distinct species of Ebolavirus viz. Bundibugyo ebolavirus (BDBV), Zaire ebolavirus (EBOV), Reston ebolavirus (RESTV), Sudan ebolavirus (SUDV) and Tai Forest ebolavirus (TAFV). While BDBV, EBOV, and SUDV have been associated with large EVD outbreaks in Africa, RESTV and TAFV have not yet been implicated in a human outbreak. The RESTV species, found in Philippines and the People’s Republic of China, can infect humans, but no illness or death in humans has been reported [3, 4]. The natural reservoir of Ebola viruses has not yet been proven conclusively. However, fruit batsHypsignathus monstrosus, Epomops franqueti and Myonycteris torquata, may be the natural hosts in Africa. Human beings can get infected and initiate human to human transmission on contact with infected animals or their carcasses. In Africa, infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest [3]. The most common mode of human-to-human transmission is direct contact through broken skin or unprotected mucous membranes e.g., the eyes, nose, or mouth, with the blood or body fluids (urine, feces, saliva, semen, and other secretions) of a person who is sick or has died of EVD. However, infection cannot be transmitted before the appearance of symptoms. Transmissionmay also occur with contaminated needles or infected animals. Ebola does not spread through the air or by water. In Africa, it can spread by handling infected bush meat. There is no evidence that mosquitoes and other insects can transmit the virus [3]. V. Mittal (*) :M. Chhabra Zoonosis Division, National Centre for Disease Control, Dte.GHS, 22-Sham Nath Marg, Delhi 110054, India e-mail: veena_m12@yahoo.com