Rapid detection of IgM and IgG antibodies to herpesviridae virus.

In this study, the immunoconcepts EA indirect enzyme antibody technique (colorzyme) was used not only for detection of IgG antibodies but also for quantitative detection of IgM antibodies to Herpes Simplex virus (HSV), Cytomegalovirus (CMV) and Epstein Barr Virus (EBV) to diagnose recent iactivei infection. Reference reactive and negative antisera and randomly collected human sera were tested by complement fixation test (CFT) against HSV antigens and tested also by immunofluorescent (IF) and colorzyme Immunoconcepts EA tests. All sera that were negative to HSV, CMV and EBV antibodies by CFT were negative by IF and colorzyme EA tests. All antibody positive sera and reference positive antisera were also positive by IF and colorzyme EA tests with slight variation in antibody titres between CFT and colorzyme test results. Human sera which were negative or IgM positive to HSV, CMV and EBV by ELISA as well as negative and positive reference sera from different diagnostic kits were retested by IF and colorzyme EA for IgM antiviral reactivity results were concordance by the three rests. All incubations in colorzyme test were at room temperature and only an ordinary microscope used in IF test or plate washers and readers needed for ELISA test. The colorzyme immunoconcepts is a simple, rapid and sensitive for viral diagnosis and can be used in any private laboratory.

Antibodies to lymphocytic choriomeningitis virus in wild rodent sera in Egypt.

Specific antibodies to lymphocytic choriomeningitis (LCM) virus were detected in sera of wild rodents trapped in different regions of Egypt. The highest proportion of positive sera (11.5%) was found in Sinaa Governorate of the Asian Continent, followed by Sharkia Governorate (5.6%) adjacent to Sinaa and Giza Governorate (1.8%). In Upper Egypt, however all 610 rodent sera collected in Aswan, Red sea Pernees and New Valley adjacent to Sudan were negative. The highest percentage of positive sera was in Rattus rattus frugivorus and Mus musculus species.

Production in Vero cells of an inactivated rabies vaccine from strain FRV/K for animal and human use.

A new concentrated and purified rabies vaccine was produced in Vero cells. Two rabies virus strains, the fixed rabies virus Pasteur (FRV) and Pittman Moore (PM) were adapted to Vero cells by 20 cycles of alternating passages in the brain of weaning mice. Intracerebral (i.c.) inoculation of weaning mice was followed then by 17 and 20 serial passages in Vero cells of RFV and PM strains, respectively. The adapted strains designated as FRV/K and PM/K gave titres of 10(6) +/- 1.5 log (LD50/ml for i.c. inoculated mice) in several harvests taken from one infected cell culture. Pooled harvests were concentrated 20-fold by ultrafiltration and were tested as animal vaccine after inactivation with beta-propiolactone (BPL). Another vaccine preparation destined for human use, in addition to concentration and inactivation, was also purified by gel filtration. Control tests revealed that the antigenic content of different strain FRV/K harvests was very high in comparison with that of strain PM/K and the reference tissue culture vaccine (RIV, Netherland). In sheep the antibody response induced by the FRV/K strain was very high; serum neutralizing index (NI) higher than 4 was reached 40 days after the second vaccine dose, whereas the vaccine preparation from strain PM/K gave NI of 2.3 and the reference vaccine NI of 3.8, respectively. Safety tests in rabbits and guinea pigs showed neither pyrogenicity nor toxicity.

Antigenic relatedness of pigeon herpes encephalomyelitis virus to other avian herpesviruses.

Pigeon herpes encephalomyelitis virus (PHEV) was compared with seven avian herpesviruses for antigenic relatedness using monospecific antisera and the indirect fluorescent-antibody (IFA), agar-gel-immunodiffusion, and serum-neutralization tests. No antigenic relationship was detected between PHEV and Marek's disease virus, turkey herpesvirus, infectious laryngotracheitis virus, and duck enteritis virus. A common precipitating antigen was detected between the PHEV and pigeon herpesvirus (PHV), owl herpesvirus (OHV), and falcon herpesvirus (FHV). These four viruses also cross-reacted in the IFA test. Weak neutralizing activity was detected only between PHV antiserum and PHEV. These results suggest that the PHEV should be classified as a herpesvirus related to, but distinct from, the PHV-OHV-FHV group of viruses with which it shares common antigens.

Rotavirus infections associated with diarrhoea in calves in Egypt.

The successful isolation and identification of rotavirus from newborn calves with diarrhoea is reported for the first time in Egypt. From 25 faecal samples taken from diarrhoeic calves, ten virus isolates were found to give cytopathogenic effects on bovine embryonic kidney cells. Three of the isolates were identified as rotavirus using fluorescent antibody staining, serum-neutralization, revealed the presence of rotavirus antibodies in 18 of 105 serum samples obtained from other calves slaughtered at Cairo abattoir.

An epidemic of Rift Valley fever in Egypt. 1. Diagnosis of Rift Valley fever in man.

Rift Valley fever (RVF) virus was isolated from 53 of 56 sera collected from patients with a clinical picture of dengue-like illness during the peak of the epidemic of RVF in Egypt in the autumn of 1977. RVF virus was also isolated from the throat washings of two patients and the faeces of four, all of whom were positive for virus isolation from the serum. All the isolates were identified by the complement fixation (CF) test. Serological diagnosis of RVF, using paired sera from 16 patients, was made by both the haemagglutination-inhibition (HI) and CF tests. HI antibodies were demonstrated in all the acute sera, whereas CF antibodies, which seem to appear later, were detected in only seven acute and twelve convalescent sera. A longer period than the 12 days in this study must be allowed to elapse between the taking of the paired sera for a definite serological diagnosis to be obtained, especially when CF antibodies are taken into account.

An epidemic of Rift Valley fever in Egypt. 2. Isolation of the virus from animals.

During the epidemic of Rift Valley fever (RVF) that occurred in Egypt and other areas of North Africa in 1977, the virus was isolated from various species of domestic animal and rats (Rattus rattus frugivorus) as well as man. The highest number of RVF virus isolates were obtained from sheep; only one isolate was recovered from each of the other species tested, viz. cow, camel, goat, horse, and rat. RVF virus was reisolated from both camel and horse sera, apparently for the first time.