Polio outbreak in Algeria: epidemiological, virological and vaccinational aspects.

During a poliomyelitis outbreak (October 1983) in El Oued territory (Algeria) 28 cases were diagnosed. All the patients were under 4 years old. The ratio of females to males was 0.33. No deaths occurred during this epidemic. 25 of the 28 polio cases were diagnosed by cell culture and 81% were polio type 1. The epidemiological survey established that the epidemic was due to the insufficiency of vaccination coverage, since the consumption of antipolio vaccine in the epidemic area had dropped by 25% from 1982 to 1983. 7 of the 28 polio cases had been given at least 3 injections of vaccine at the correct intervals. 5 of 8 vaccine samples from the epidemic area had an insufficient titre of polio type 1. These observations showed that the nature of the vaccine, whether killed or live virus, was less important for controlling poliomyelitis than providing medical and sanitary facilities to ensure good vaccination coverage.

[Diagnosis of rabies infection in animals using monoclonal antibodies]. / Diagnostic de l'infection rabique chez l'animal par le biais des anticorps monoclonaux.

Two monoclonal antibodies (M.A.), specific for viral nucleocapsid, the M.A. D-20 and the M.A. D-43 raised against a fixed strain of rabies virus (C.V.S. 11), have been tested in parallel with a standard antirabies serum (S.A.R.) in diagnosis of animal rabies virus infection. 44 brain imprints from animals which died from rabies were tested by indirect immunofluorescent technique with monoclonal antibodies. Constant correlation has been found between the M.A. D-43 and the S.A.R. in the diagnosis of animal rabies virus infection in all cases studied. For M.A. D-20, concordance of results with S.A.R. was found only in limited number of cases.

[Production of monoclonal antibodies against a wild strain of rabies virus]. / Production d'anticorps monoclonaux vis-à-vis d'une souche sauvage de virus rabique.

Production of monoclonal antibodies against a wild strain of rabies virus. Cell fusion of SP 2/O, a murine myeloma against a wild strain of rabies virus has originated five monoclonal antibodies (M.A.) specific for virus nucleocapsid , one M.A. specific for virus glycoprotein and one M.A. specific for a viral membrane protein.

Detection by monoclonal antibodies of an antigenic determinant critical for poliovirus neutralization present on VP1 and on heat-inactivated virions.

Hybridoma cell lines were established against poliovirus type 1 (Mahoney) heat-denatured virions (C particles). Each anti-C monoclonal antibody (McAb) immunoprecipitated specifically one of the individualized poliovirus capsid polypeptides VP1, VP2, or VP3. One of the anti-C McAb (C-3), reacting with VP1, neutralized homologous virus and immunoprecipitated infectious D particles. Its properties have been compared to those of a neutralizing anti-D McAb (D-Ic). In contrast with the C-3 antigenic site, the D-Ic epitope was not present on C particles nor on individualized structural polypeptide. This demonstrates that C-3 and D-Ic epitopes represent two independent antigenic determinants, both critical for poliovirus neutralization.

Occurrence of viruses in human stools in the Ahaggar (Alberia).

From October 1977 to May 1980, 243 stools collected in sedentary and semi-nomadic populations of the Ahaggar (Algerian Sahara) were examined using immunoelectronmicroscopy and tissue culture inoculation. Immunoelectronmicroscopy revealed the presence of rotaviruses in 8, coronaviruses in 26, adenoviruses in 5 and small round viruses in 4. Enteroviruses were isolated in tissue culture from 24 stools. Rotaviruses were present in the Ahaggar but were associated with little acute enteric disease. The high frequency of coronaviruses both in gastroenteritis patients and in patients without disease was surprising. The prevalence of enteroviruses in this hyperarid zone was similar to or higher than that found in noticeably more human countries. Further systematic bacterial, viral and parasitic examinations are required to clarify the role of the above viruses in the aetiology of gastroenteritis in this region.