EBOLA VIRUS DISEASE: WHAT WE MUST KNOW

Abstract

The disease known as ébola receives this denomination for the name of the closer river to the African district, where the first cases of the outbreak were presented in the decades of the seventies of the 20th century (1). This zoonosis that is affecting Africa and currently spreading itself to other continents, attracts attention of the sanitary authorities worldwide. The virus belongs to the family Filoviridae, genus Ebolavirus (EBOV) and they are divided in the species Bundibugyo ebolavirus, Reston ebolavirus, Sudan ebolavirus, Tai Forest ebolavirus y Zaire ebolavirus (2). The origin of the disease is unknown, the first outbreak of EBOV was reported in Sudán in 1976 and three weeks later in Zaire, today named Democratic Republic of the Congo [DRC] (3). Then the frequency of cases decreased, being reported small outbreaks until that in 1994 the virus began tour in oriental direction, with progressive increase of the cases since Gabón to DRC and Uganda (4-6). At this moment, a new outbreak exists that could not have been contained. For September 4th of the year in process, 3707 cases had been reported, including 1848 deaths (7), distributed between Guinea (771 cases and 494 deaths), Liberia (1698 cases and 871 deaths), Sierra Leona (1216 cases and 476 deaths), Nigeria (21 cases and 7 deaths) and Senegal (1 case). Added to the previous information, the last August 26 the Ministry of Health of the DRC notified to the WHO a new outbreak in its equatorial province (8). In an attempt for understanding the natural history of the disease, studies in vertebrates (bats and rodents) and arthropods related to the index case or site of the outbreak have been carried out, without viral isolation or antibodies anti- EBOV obtained (9,10). Due to the fact that the monkeys develop a hemorrhagic symptomatology similar to that of the human beings with later death, they are not considered to be asymptomatic carriers (11). It has been indicated that a bat lodges the virus, also apparently the antelopes and the porcupine. An important emptiness of knowledge exists in the matter. In 1999, 242 small mammals were studied, detecting the EBOV glycoprotein and sequences of the gene of the polymerase in animals belong to two genuses of rodents and a specie of shrew (12), indicated as reservoir of the disease.