Development of a dual recombinant vaccine to protect small ruminants against peste-des-petits-ruminants virus and capripoxvirus infections.

A recombinant capripoxvirus vaccine containing a cDNA of the peste-des-petits-ruminants virus (PPRV) fusion protein gene was constructed. A quick and efficient method was used to select a highly purified recombinant virus clone. A trial showed that a dose of this recombinant as low as 0.1 PFU protected goats against challenge with a virulent PPRV strain.

[Evaluation of vaccinal protection against rinderpest in Cameroon. III. General evaluation]. / Evaluation de la protection vaccinale contre la peste bovine au Cameroun. III. Evaluation globale.

The national veterinary Laboratory, Garoua (Cameroon) has been carrying out rinderpest sero-surveillance since 1989 as part of an effort made by the Panafrican Rinderpest Campaign (PARC) to control rinderpest in Africa. In 1993, 8517 serum samples collected from 286 cattle herds (from 0 to 3 years old) randomly chosen from six provinces with large cattle population (Far-North, North, Adamaoua, East, West, North-West) were tested using the rinderpest competitive ELISA technique; the herd immunity level was 54%. Out of 2010 serum samples from 68 non-protected cattle herds tested using the peste des petits ruminants (PPR) ELISA technique, 91 samples were positive (4.5%): this does not significantly increase the cattle immunity level against rinderpest. Significant differences in the immunity rates between provinces were observed. Suggestions to increase the immunity level are discussed.

[Evaluation of vaccinal protection against rinderpest in Cameroon. II. The North province]. / Evaluation de la protection vaccinale contre la peste bovine au Cameroun. II. La province du Nord.

Cameroon joined the sero-survey component of the PARC (Pan African Rinderpest Campaign) program in 1989. During the 1992 Campaign, a detailed sampling frame, adapted to the breeding conditions of the North Province was drawn up according to PARC recommendations. The four administrative divisions of the province were covered by sampling cattle in 14 sites chosen by randomisation. Eight thousand six hundred and eighty sera samples from 217 cattle herds were tested using FAO/IAEA rinderpest competitive ELISA technique. The results indicated an overall prevalence of rinderpest virus antibodies (RPVA) of 66%. This is below the target objective. The differences of prevalence between age groups and breeding systems (sedentary of transhumant) are statistically significant. The same results have been reported in the Adamaoua Province (62% in 1991 campaign). These results do not reflect the situation in all the country. It is suggested to hold general meeting between different livestock managers from the provinces with high cattle populations to adopt commun vaccination measures with the target objective of increasing the level of immunity.

[Main infectious agents involved in the etiology of lung diseases of small ruminants in northern Cameroon]. / Etude des principaux agents infectieux intervenant dans l'étiologie des pneumopathies des petits ruminants au Nord-Cameroun.

Between 1990 and 1992, 91 necropsies of small ruminants affected with pulmonary illness led to the isolation of the following strains of Mycoplasma (M.): M. mycoides subsp. mycoides LC, M. ovipneumoniae, M. agalactiae, M. sp. type D2 and M. arginini. Eleven Pasteurella multocida strains (serotypes A1, A3, A5, A7 and D2) and 11 Pasteurella haemolytica strains (serotypes 1, 2, 3, 6, 7, 8 and 9) were isolated. Corynebacterium pseudotuberculosis, Actinomyces pyogenes, Staphylococcus sp., Streptococcus sp., Bacillus sp. and Mycobacterium sp. were also isolated. Thirty-two antibiograms were performed on Pasteurella, Corynebacterium pseudotuberculosis and Actinomyces pyogenes strains. Eighty eight p. cent were sensitive to penicillin G and oxytetracycline, and 84% to chloramphenicol; 50% were not sensitive to spiramycin and 47% to streptomycin. One Capripoxvirus strain was isolated on sheep. Pest of small ruminants (PPR) virus was detected by immunocapture ELISA test performed on some lung samples. Two serological surveys, one for contagious caprine pleuropneumonia (898 goats), between 1991 and 1993, and one for PPR (902 sheep and goats) in 1993, were conducted in the North and Far North provinces. No antibody against contagious caprine pleuropneumonia was detected. Among the animals in the sample, PPR prevalence was 64 +/- 7% in the Far North province and 14 +/- 3% in the North province. Concerning control measures, a vaccination campaign against small ruminant pasteurellosis appears to be hardly feasible because of the antigenic diversity of the isolated Pasteurella strains. PPR is endemic especially in the Far North province. The efficiency of a vaccination campaign against PPR must be estimated with a field survey.

[Evaluation of the vaccinal protection against rinderpest in Cameroon. I. Province of Adamaoua]. / Evaluation de la protection vaccinale contre la peste bovine au Cameroun. I. La province de l'Adamaoua.

As a part of the panafrican rinderpest campaign, a serological survey of 5,720 samples was undertaken in the Adamaoua province of Cameroon. The herd immunity level varied from 60 to 73% in the four departments investigated. Vaccination of all animals from the age of six months, replacement of vaccination equipment, restoration of crushes, and use of magnesium sulfate, or as a substitute, saline for lyophilized vaccine reconstitution are recommended.