The spread of infectious diseases due to globalization and climate change has become one of the serious ongoing problems all over the world. Modern transportation facilitates fast movement of infected people and animals, as well as contaminated agricultural and biological products to new areas with naïve populations causing serious outbreaks and heavy consequences. An additional way of rapid spread of infections is through the increasing number of blood sucking insects in densely populated areas and the close contact between natural habitats and urban areas. These environmental changes have driven the adaptation of exotic pathogens to urban conditions, as happened, for example, with Dengue and Ebola viruses. The increasing number of immunocompromised individuals (including patients undergoing organ transplantation, anti-cancer therapy or suffering from AIDS) ease the adaptation of some animal’ infections to humans. Moreover, climate change allows blood sucking insects to spread to new areas and transmit infections to host animals as well as to local blood sucking insects, which become additional vectors for transmission of viral diseases.
In addition to clinical disease in naïve hosts, some viral infections also lead to abortions and malformations in fetuses. The most known viruses capable of inducing malformations in humans are Rubella and recently Zika viruses. In case of livestock animals congenital diseases have severe economic impact on the industry due to the dramatic decrease in number of healthy offspring. Death of the fetuses, abortions, stillbirths and malformations, as well as complications in parturition (often followed by culling of injured mothers and congenitally malformed newborn animals), and high proportion of death among young animals all heavily affect the agricultural industry.
Members of several families of viruses are capable of affecting fetuses and, consequently, newborn animals. These include foot and mouth disease, encephalomyocarditis virus and others belonging to the Picornaviridae family and viruses belonging to the order Herpesvirales, mostly viruses from the Alfaherpervirinae subfamily. Dengue and Zika viruses in humans and pestiviruses in animals are the main abortogenic/teratogenic viruses of the Flaviviridae family. However, the most known virus causing abortion storms in many mammals and humans is Rift Valley fever virus belonging to the order Bunyavirales. Viruses belonging to the Simbu serogroup, genus Othobunyavirus, of the Peribunyaviridae family are the main reason of abortions and malformations in domestic ruminants. Additionally, members of Reoviridae family (mainly belonging to the genus Orbivirus including bluetongue and epizootic hemorrhagic disease viruses) may also cause pregnant abnormalities in ruminants and members of Paramyxovidae, Arteriviridae, Circoviridae and, Parvoviridae are also involved in cases of malformation and abortions in human and animals.
Almost three hundred aborted fetuses and newborn dead domestic and wild ruminants were tested for presence of viral RNA and DNA in the Kimron Veterinary institute, Israel, during routine investigation of aborted fetuses from March 2018 till March 2019 (13- month period). It was found that 10-30% of fetuses were positive in real-time polymerase chain reaction for viruses belonging to the Simbu serogroup. A less dramatic situation was observed with bluetongue viruses and pestiviruses, where viral RNA was detected in 1-4% of aborted fetuses or newborn dead animals. Infectious rhinotracheitis virus (herpesvirus) was found in approximately 1% of tested cattle aborted fetuses. Notably, most serotypes of bluetongue viruses and species of Simbu serogroup viruses which were recently identified in Israel, probably originated from Africa.
During the last two decades many types of viral disease were reported in areas, where such viruses were previously exotic. Strict control for food and biological industry products can prevent the spread of many infections among people and animals
Natalia Golender graduated with honors the Veterinary faculty of Samarkand Agricultural Institute, Uzbekistan in 2002. She was working as a veterinarian in the division of poultry and fish diseases, Kimron Veterinary Institute, Israel during 2004-2010, mostly on diagnosis and study of avian influenza viruses. Since 2010 she is working in division of virology at the Kimron Veterinary Institute in diagnosis, as well as in experimental, clinical, genetic and epidemiologic investigation of several arboviral infections affecting ruminants.