Identification, geographic distribution and risk factors of Brucella abortus and Brucella melitensis infection in cattle in Algeria.

Brucellosis is an infectious disease of several terrestrial and marine animals and humans caused by bacteria of the genus Brucella. This study aimed to identify Brucella species and biovars circulating in cattle and to analyze their geographic distribution across Algeria. Two hundred ninety eight milk and lymph node samples from 161 seropositive cattle of different local and foreign breeds were collected from 97 dairy farms in 56 towns of 13 wilayas (states/ provinces) of the central, eastern, western and southern regions. The samples were cultured on selective media and the obtained isolates were identified using bacteriological and molecular tests. Eighty-five Brucella isolates (72 B. abortus and 13 B. melitensis) were recovered from 63 animals in 37 dairy farms. In total, 71 (83.5 %) B. abortus bv 3, 11 (12.9 %) B. melitensis bv 2, 2 (2.4 %) B. melitensis bv 3 and 1 (1.2 %) unidentified B. abortus biovar were detected. The identification of B. abortus biovar 3 and B. melitensis biovar 2 is a new finding for Algeria and the Maghreb, respectively. B. abortus (84.7 %) was the main etiological agent of brucellosis. B. abortus showed a scattered distribution across Algeria. The fact that 60 % of the seropositive cattle showed no clinical signs, but 36 % were culture positive is an alarming observation. These data will rise awareness for the current epidemiological situation of bovine brucellosis in Algeria. To the best of our knowledge, this is the first representative countrywide bacteriological investigation of Brucella species and biovars in cattle across Algeria, which is a developing country where resources might be limited and the working conditions might not be very friendly.

Pertussis in north-central and northwestern regions of Algeria.

INTRODUCTION: Pertussis outbreaks continue to occur in many countries despite high vaccination coverage. Under-diagnosed cases in adolescents and adults may result in increased transmission to infants, who are at risk of severe pertussis. Additional measures to protect both groups should be considered. METHODOLOGY: Nasopharyngeal samples and sera were collected from patients and household contacts with clinically suspected pertussis. Diagnoses were confirmed by culture, real-time polymerase chain reaction (PCR), and serology. Bordetella pertussis isolates were characterized by antimicrobial sensitivity and fimbrial serotyping. RESULTS: Of 392 participants, 134/248 patients (54%) and 66/144 contacts (45.8%) had confirmed pertussis infections. B. parapertussis was not detected. All B. pertussis isolates were sensitive to the antibiotics tested, and all expressed the Fim3, not the Fim2, fimbrial serotype. Most patients (81.2%) were <6 months (51.8% of whom were <3 months) of age; 77.6% were unvaccinated, and most positive contacts were mothers 20-40 years of age. CONCLUSIONS: Despite high vaccination coverage, pertussis is circulating in Algeria. Most infections occur in unvaccinated infants <6 months of age, with mothers as the main source of infection. An adolescent/adult booster should be considered. Adoption of sensitive and specific laboratory tests would improve pertussis diagnosis and surveillance.