potential role of pigs in the enzootic cycle of rift valley fever at Alexandria Governorate, Egypt

This study was carried out to clarify the possible role of pigs as intermediate host for Rift Valley Fever [RVF] virus through detection of antibodies to RVF in the sera of pigs and human contacts. Two hundreds and forty five of pig blood samples and forty three blood samples of human contacts to the pigs [Veterinarian and their assistants, butchers and Abattoir workers] were collected from pigs1 abattoir at Alexandria governorate, Egypt. Blood samples were subjected to the detection of RVF antibodies by both ELISA and HAI techniques. The detection rate of RVF antibodies in pig sera by ELISA was 37 positive [15.1%] out of 245 tested sera samples. The highest detection rate of positive samples was in winter season [12 out of 58, [20.69%] and the lowest detection rate was at summer season [7 out of 70, [10.0%], while it was 9 [15.79%] and 9 [15.0%] positive out of 57 and 60 tested sera samples in spring and autumn seasons respectively with no significant differences between them. When HAI technique was applied to detect the RVF antibodies in pig sera, it gave only 20 positive samples out of 245 [8.16%] with highest detection rate was also in winter 7 [12.07%] while it was only 1 [1.43%] in summer season with significant differences between the results obtained in the summer season and those of autumn and winter seasons. History was taken from all of human contacts to exclude the possibilities of taking neither vaccination nor infection from other sources. The detection rates of antibodies against RVF virus in human contacts were 6 [13.95%] and 3 [6.98%] by ELISA and HAI techniques respectively. Our study does not exclude that, pigs act as a possible intermediate host in the maintenance cycle of RVF virus

Comparative study between Elisa immuno diffusion and cell bound immuno assay techniques for detection of anti bovine viral diarrhea antibodies in calves of some farms in Alexandria and Behira Governorates

Rapid, highly sensitive and specific technique is essential need for early diagnosis of Bovine Viral Diarrhea [BVD] infection in calves to prevent, control and eradicate the persistently infected animals; so, ELISA, Immuno-diffusion [ID] and Cell bound immuno assay [CBIA] techniques were compared for detection of anti-Bovine Viral Diarrhea [anti-BVD] antibodies in 240 calves blood samples of some farms in Alexandria and Behira Govcrnorates [120 each]. Out of total 240 tested blood samples; 143 [59.6%], 47 [19.6%], and 155 [64.6%] were positive for anti-BVD antibodies using ELISA, ID and CBIA respectively. The highest detection rate was found in diseased calves at Behira Governorate [83.5%> using CBIA technique, while the lowest detection rate was found in contact calves at Alexandria Governorate [3.2%] using ID technique. The percentage of agreement between CBIA and each of ELISA and ID was 95% and 55% respectively for detection of anti-BVD antibodies in Calve sera. The percentage of sensitivity between CBIA and each of ELISA and ID was 100%, while the percentage of specificity between CBIA and each of ELISA and ID was 87.6% and only 44% repectively for detection of anti-BVD antibodies in calves sera. This study showed that, the CBIA as well as ELISA techniques were highly sensitive and specific tests for detection of anti-BVD antibodies in calves sera when compared to ID technique. Moreover, CBIA has many advantages over ELISA technique; Firstly. CBIA is rapid, simple, cheap and not need to ELISA reader as in ELISA technique. Secondarily; the microtitre plate containing BVD infected tissue culture monolayer can be preserved for long time in comparison to prepared ELISA plates

Foot and mouth disease [FMD]: serological investigation in some farms of Alexandria governorate of Egypt

Suspected cases of foot and mouth disease [FMD] in cattle were noted in some farms of Alexandria governorate during the period from January to March 2000. The investigated cattle suffered from oral and foot lesions associated with lameness in addition to fever in some and inappetance in others. At the same time, the contact workers and veterinarian suffered from fever during the course of the disease in cattle. Blood samples were withdrawal from suspected cases of cattle [31 cows] and from 24 contact cases. Saliva and vesicular lesions of the tongue were taken on glycerol buffer saline for isolation and serotyping of FMD virus by hyperimmune sera. The virus was isolated from all saliva and vesicular lesions of the diseased animals and serotyped as FMD01. Only 10 out of 24 contact cases were positive by ELISA for anti-FMD antibodies. Also, 25 blood samples were withdrawal from contact persons with diseased animals and were suffered from fever. While, 25 blood samples were taken from contact persons who did not suffer from fever. Moreover, 5 blood samples were taken from persons who were not in contact with any veterinary source [children] and were used as negative control. A total of 13 out of 25 and 2 out of 25 were positive for anti-FMD antibodies from diseased and contact persons, respectively

Application of reverse transcriptase - polymerase chain reaction for detection of rift valley fever viral antigen from mosquito

A reverse transcriptase polymerase chain reaction [RT-PCR] was applied to detect rift valley fever virus [RVFV] in Culex pipiens mosquito pools collected from Alexandria and Behira governorates of Egypt [50 pools each]. All mosquito pools were subjected to double sandwich enzyme linked immunosorbent assay [ELISA] technique to detect RVF viral antigen. Out of all 100 mosquito pools, only 18 were positive by ELISA, 10 out of 50 pools were positive in Behira Governorate and 8 were positive in Alexandria Governorate. All positive samples [18], in addition to two negative samples [one was used as a negative control and the other was used as a positive control after the addition of 1.0 ml of 103 inactivated RVF virus] were subjected to RT-PCR. Out of these 18 positive samples by ELISA, only 7 were positive for RVF Virus by RT-PCR. These results gave the possibilities of the existence of other phleboviruses that cross react with RVF virus

potential role of rattus rattus in enzootic cycle of rift valley fever in Egypt 1- detection of RVF antibodies in R. rattus blood samples by both enzyme linked immuno sorbent assay [ELISA] and immuno-diffusion technique [ID]

Three hundreds of Rattus rattus [R. rattus] were trapped from 3 different governorates of Egypt [one hundred each], blood samples were withdrawal and subjected for detection of anti-RVF antibodies by both ELISA and ID techniques. The prevalence rate of antibodies by ELISA were 88 [29.33%] positive out of 300 tested blood samples, the highest rate was in Behira governorate 36 [36%] and the lowest one was in Alexandria governorate 22 [22%] while it was 30 [30%] in Minia governorate. But when ID technique was applied it gave only 18 [6%] positive samples out of 300 tested blood samples with the highest rate in Behira and Minia governorates [8%] and it was only [2%] in Alexandria governorate. Our study suggests that these R. rattus make possible candidate as intermediate host in the maintenance cycle of RVF in Egypt