Human rabies in Israel

Emergence of dog rabies in the northern region of Israel

Between 1979 and 2000, foxes constituted the main reservoir of rabies in the Northern regions of Israel. Following the implementation of the fox-targeted oral vaccination programme (ORV) in 1998, rabies was eradicated from this area. Subsequently during 2004-2007, the biological and molecular characterization of the rabies isolates showed that stray dogs emerged as the main animal reservoir in Northern Israel while lower numbers of cases were reported in domestic animals. The virus isolates from foxes and dogs differed, in their molecular characterization, suggesting two distinct separate lineages. The transition from fox-mediated rabies to dog-mediated rabies is of great concern to public health because of the close contact between dogs and the human population.

Identification of novel canine rabies virus clades in the Middle East and North Africa

Four novel phylogenetic clades of canine rabies virus (RABV) variants have been identified in the Middle East and North Africa. The three novel Middle Eastern clades comprise RABV isolates from the borders between Israel and neighbouring countries. The North African clade (Africa 4) comprises four RABV isolates from Egypt and one from Israel. We characterized various RABV lineages antigenically by using a panel of monoclonal antibodies to the nucleoprotein (N) and phylogenetically by analysis of entire N gene sequences. The estimated mean substitution rate for the N gene alignment (2.7x10(-4) substitutions per site per year) is comparable with previous estimates for RABV. The application of a molecular clock indicates the emergence of current canine RABV diversity to have occurred at about the same time (approx. 1870) in the Middle East and Europe, following divergence from established lineages in Africa and Asia.

Molecular fingerprinting of Leishmania infantum strains following an outbreak of visceral leishmaniasis in central Israel

Human and canine visceral leishmaniasis caused by Leishmania infantum emerged in central Israel after an absence of over 30 years. The origin of this outbreak was investigated by examining genetic polymorphisms in 37 strains isolated from dogs and patients with visceral leishmaniasis in the continuously active northern Israeli and West Bank foci and in a new Israeli focus using DNA fingerprinting with the human multilocus minisatellite probe 33.15. Analysis of the patterns obtained by DNA fingerprinting separated the strains geographically into northern (clade B) and central (clades A and C) genotypic groups. These results suggest that the emergence of visceral leishmaniasis in central Israel is due not to parasite spread from northern Israel to the new focus but rather to increased parasite transmission in central Israel and the West Bank coupled with changes in the ecoepidemiology of this region.

Rabies virus detection by RT-PCR in decomposed naturally infected brains

The warm climate of Israel and mishandling of the cadavers during transit to the laboratory requires an accurate method for diagnosis of rabies in decomposed tissues. By using the reverse transcriptase polymerase chain reaction (RT-PCR) 10 decomposed brain samples that collected between 1998 and 2000 were diagnosed as negative by direct fluorescent antibody test (FAT), were found positive. Three of the 10 decomposed brains were confirmed as positive by isolation of rabies virus in tissue culture and by mouse inoculation (MIT) while the other seven decomposed samples were found positive only by RT-PCR. Direct sequencing and molecular analysis of a 328bp fragment of the N gene of all the rabies sequences confirmed their geographical origin. These results demonstrated the importance of the RT-PCR in the detection of rabies virus in decomposed naturally infected brains, especially in cases when the sample is not suitable for other laboratory assays. Thus, the RT-PCR can provide a positive diagnosis; however, when a negative result is obtained due to the nature of the decomposed tissue that can be caused by technical reasons and a false negative might be the case.

Molecular epidemiology of rabies virus isolates from Israel and other middle- and Near-Eastern countries

A total of 226 isolates of rabies virus from different areas of Israel, including three human isolates and one sample from South Lebanon were identified between 1993 and 1998 by direct immunofluorescence using monoclonal antibodies to the viral nucleoprotein (N). An epidemiological survey based on nucleotide sequence analysis of 328 bp from the C terminus of the N coding region and the noncoding region between the nucleoprotein and the phosphoprotein (NS gene) was performed. Phylogenetic analysis of the isolates from Israel showed that they were related geographically, but not according to host species. Five variants, related groups distributed among four geographical regions, were identified. In each region, rabies virus was isolated from more than one animal species. A comparison of the sequence analysis of rabies virus samples from the rest of world revealed a 2-nucleotide change that distinguished the Middle East variants from the rest.