Rabies and bats in a rabies-endemic area of southern Africa : application of two commercial test kits for antigen and antibody detection

In southern Africa, isolates of rabies-related viruses (i.e. Duvenhage virus and Lagos bat virus) have been made from insectivorous and frugivorous bats. As no recent formal bat virus survey has been reported in southern Africa, a survey of bats in rabies-endemic areas was undertaken. Five hundred and forty seven bats (13 species) were collected from 21 localities in the Orange Free State, Lesotho and the northern Cape Province. None of the 190 bat sera tested using the "Trousse Platelia® Rage" ELISA kit (Diagnostic Pasteur), had antibodies to rabies virus glycoprotein G. Rabies virus nucleocapsid antigen was also sought for in the brains of 530 bats (13 species) by means of the "Rapid rabies enzyme immunodiagnosis" (RREID)® test (Diagnostics Pasteur) . No positive results were obtained. These results show that bats are unlikely to play an important role as hosts of rabies in these parts of Africa, although a low rate of infection cannot be excluded.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Medical Research Council. Central Research Fund of the University of the Orange Free State.mn201

The binding potential of commercial antibody conjugates with sera of various small terrestrial mammals

Infectious diseases of wild animals are of increasing importance, both from an economic viewpoint and because several of these diseases are pathogenic to man. However, serosurveys to determine the circulation of infectious organisms in wildlife are complicated by the fact that antibodies to species-specific immunoglobulins are not available for use in serological assays such as enzyme-linked immunosorbent assays (ELISAs) or immunofluorescence assays. To determine the binding potential of four commercially available antibody conjugates with the sera of wild animals, sera from 27 species of small terrestrial mammals were allowed to react with alkaline phosphatase-labelled protein A, anti-rabbit lgG, anti-mouse lgG and anti-human lgG by by the use of an ELISA. It was found that sera from some species of the order Lagomorpha bound optimally to anti-rabbit lgG, while anti-mouse lgG could be used for most species of Rodentia. For all Carnivora, lnsectivora, Macroscelidea, Hyracoidea and other Rodentia, staphylococcal protein A demonstrated optimal binding. None of the sera that was tested bound to anti-human lgG. These results demonstrate that commercial conjugates can be used in serological assays in which wild animal sera are used, and should be useful for future serosurveys to determine the circulation of infectious agents in small terrestrial mammals.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Could bats act as reservoir hosts for Rift Valley fever virus?

The inter-epizootic reservoir host of Rift Valley fever virus (RVFV) remains unknown, although the namaqua rock rat, Aethomys namaquensis, as well as bats have been implicated. Bats can be asymptomatically infected with rabies, as well as several arboviruses; the possibility that they can act as host for RVFV therefore exists. To examine this possibility, 350 different samples (brain, liver, salivary glands and brown fat) obtained from 150 bats (comprising seven species) were tested for RVFV antigen using an enzyme linked immunosorbent assay (ELISA). None of the samples tested positive, but the ELISA proved to have limited sensitivity (≥103 TCID50/ml). In order to determine whether bats could be infected with RVFV, one Miniopterus schreibersii and two Eptesicus capensis bats were inoculated by the oral or intramuscular route with 100 ml and 30 ml, respectively, of a RVFV suspension with a titre of 106 TCID50/ml. None of the bats developed any clinical signs. A low concentration of RVFV antigen was found in the liver and urine of M. schreibersii, but not in brain tissue. A third E. capensis bat was inoculated by the intramuscular route and sacrificed on day 18. A low level of antigen was detected in the brown fat. These results demonstrate that bats can be infected with RVFV, and that further studies should be done to determine the potential of different bat species to act as reservoir hosts for RVFV during inter-epizootic periods.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format