Enquête sérologique de la brucellose bovine au Cameroun

Abstract

A partir d’août 2002 jusqu’à juillet 2003, une enquête sérologique a été conduite à l’abattoir de Dschang (Ouest Cameroun) afin de déterminer la prévalence de la brucellose bovine. Huit cent quarante sérums bovins ont été examinés par l’Elisa indirect (iElisa) et le test au rose bengale (TRB). La séroprévalence de la brucellose a été de 9,64 et 4,88 p. 100 en utilisant respectivement l’iElisa et le TRB. Quatre-vingt et un sérums positifs avec iElisa et 50 sérums sélectionnés aléatoirement parmi les sérums qui ont été négatifs en iElisa et TRB ont été examinés par le test de fixation du complément (TFC) et le test d’agglutination lente de Wright avec Edta (SAW-Edta). Tous les échantillons négatifs en TRB/iElisa ont été confirmés comme étant négatifs par les autres tests, suggérant que le TRB et l’iElisa montraient une haute spécificité dans la population testée. Parmi les sérums iElisa positifs, 37,8 p. 100 ont été classés positifs par SAW-Edta, TRB et TFC, 39,2 p. 100 ont été classés négatifs par SAW-Edta, TRB et TFC, et 23,0 p. 100 ont été classés positifs dans un ou deux des trois tests de confirmation. Etant donné le manque de sensibilité des tests de confirmation, en particulier lors d’infections chroniques dans des systèmes d’élevage extensifs (pastoralisme), la meilleure estimation de la prévalence réelle de la brucellose a été basée sur les résultats en iElisa et a été de l’ordre de 10 p. 100.

Seroprevalence and Associated Risk Factors of Brucellosis among Indigenous Cattle in the Adamawa and North Regions of Cameroon

“…Lower seroprevalence was also reported by Ojong [ 17 ] (4.6%) using RBPT in indigenous cattle in Northwest region. The finding of this study is close to the report of Shey-Njila et al [ 11 ] (9.64%) who used indirect ELISA in indigenous cattle in the Western Highlands Regions. However, Bornarel and Akakpo [ 37 ] found a brucellosis seroprevalence of 12.5% in the Northern Cameroon and several other studies have reported brucellosis seroprevalence ranging from 7 to 31% [37, 38, 39, 40, 41, 42].…”

“…Ibrahim et al [ 7 ] and Boukary et al [ 38 ] have reported that transhumance animals were major risk factor for brucellosis in sedentary animals and that the prevalence of brucellosis increased in sedentary herds that share same environments (pasture, water points, shelter) with animals on transhumance. In conformity with the seroprevalence rates reported in various parts of Africa [ 1 , 3 , 34 , 35 , 38 , 40 , 45 , 46 ], previous works have observed higher rates in the more humid (4.6–9.6%) [ 9 , 11 , 17 ] than dryer (3%) [ 18 ] regions of Cameroon. However, the reason for higher individual seroprevalence rates recorded in regions with dry climates such as Mali [ 47 ], Burkina Faso [ 48 ], and Algeria [ 49 ] is not clear.…”

“…Human brucellosis is mainly associated with B. abortus , B. melitensis , and B. suis [ 2 ]. Bovine brucellosis is widespread in Africa, where it remains one of the most important zoonotic diseases [ 5 , 6 ], with prevalence ranging from 5% to over 70% in sub-Sahara African countries [ 1 , 7 , 8 ] including Cameroon [ 9 – 11 ]. Brucellosis has important public health significance but it is a “neglected zoonosis” in Cameroon.…”

“…However, presumptive seroprevalence studies in parts of Cameroon have shown that bovine brucellosis is endemic. For instance, using Rose Bengal Plate test (RBPT), complement fixation, indirect Enzyme-Linked Immunosorbent Assay (i-ELISA), and slow agglutination of Wright with ethylenediaminetetraacetic acid (EDTA) tests, seroprevalence rates in the range of 3–16% of brucellosis in cattle in parts of the Western Highlands and Adamawa Regions of Cameroon [ 9 – 11 , 15 , 17 , 18 ] have been recorded. However, the performance and accuracy of a diagnostic test can be evaluated by comparing its sensitivity and specificity with those of a goal test or analyzing it with several tests using latent models [ 19 – 23 ].…”

Seroprevalence, and molecular detection of Brucella abortus in cattle tissues from an abattoir in Namibia

“…The slaughter of predominantly mature cattle may have overestimated the seroprevalence of brucellosis in the current study. Higher abattoir prevalence rates than in the current study have been reported in Nigeria (3.9%) [ 46 ], Tanzania (4.7%) [ 47 ] and several African countries [ 48–54 ] where the vaccination of cattle against brucellosis is limited to absent. The proportion of brucellosis infected cattle farms identified at the abattoir (9.6%) was low, and similar to the prevalence of infected farms (9.3%) reported previously in Namibia [ 26 ], which is an endorsement of the effectiveness of brucellosis control measures implemented in the country.…”