ABSTRACT
Tuberculosis (TB) is considered one of the most widespread and devastating zoonotic diseases in low-income countries, with a cosmopolitan distribution. The aim of this 10-year retrospective survey (from 2011 to 2020) was to determine the frequency of bovine, ovine, and goat tuberculosis in different local slaughterhouses across Constantine Province, Algeria. The control of livestock carcasses was systematically performed by veterinarian inspectors, after each stage of the slaughter process. The routine abattoir inspection included the detection of visible abnormalities on different organs and lymph nodes. The overall prevalence of tuberculosis recorded in slaughtered animals was 0.83%, with the following distribution among species: 2.73% in cattle, 0.001% in sheep, and 0.0% in goats. During the study period, there was a strong correlation (R = 0.82) (p < 0.01) between tuberculosis occurrence and the number of slaughtered cattle. Fluctuations in monthly TB prevalence ranged from 2% to 24.8% between 2018 and 2020, although there were no statistically significant correlations between infection and the age or gender of the animals, except for the year 2020 when a significantly higher (p = 0.017) percentage of TB cases were recorded in female cattle compared to male cattle. The average monthly weight of the confiscated livers and lungs ranged significantly (p ≤ 0.05) from 150 kg to 350 kg. The study results provide baseline data regarding livestock tuberculosis monitoring in the area of Constantine, Algeria, indicating that the disease incidence is not highly alarming, yet remains a serious public and animal health issue in the screened region.
ABSTRACT
BACKGROUND AND AIMS: Polymorphisms within genes encoding the cytokines involved in anti-tuberculosis immunity have been widely studied and sometimes associated with an increased risk of developing the active form of tuberculosis (TB). This study analyzes for the first time the impact of two polymorphisms, namely IFNG+874 T/A and IL10-1082 G/A, in the Algerian population where tuberculosis is moderately endemic. METHODS: This case-control study included 104 healthy controls and 141 active TB patients: 75 extrapulmonary (EPTB) and 66 pulmonary (PTB). They were all genotyped by refractory mutational system-PCR amplification. In order to measure the functional impact of IFNG+874 T/A on the production rate of IFN-γ, 43 patients performed a QuantiFERON®Gold In-tube test. RESULTS: The IFNG+874 AA genotype was associated with a higher risk of developing EPTB (OR = 2.52; 95%CI = 1.23-5.18; p = 0.012) while the IFNG+874 TA genotype was associated with a greater protection (OR = 0.34, 95%CI = 0.16-0.74; p = 0.006) which was further characterized by a high production of IFN-γ (p = 0.001). Similarly, the allele A of SNP IL10-1082 G/A, especially in its homozygous form (AA), were overrepresented in PTB patients (p = 0.010 and 0.019, respectively). The combination of both susceptibility genotypes (AA/AA) was strongly associated with risk of development of active TB (OR = 8.58; 95% C.I = 1.95-37.70, p = 0.004). This susceptibility combination was only significant in men regarding PTB (OR = 11.05; 95% C.I = 1.32-92.72, p = 0.027). Additionally, IFNG+874 TA and IL10-1082G∗ genotypes combination was mostly encountered in men controls and conferred the highest protection rate against EPTB (OR = 0.25; 95% C.I = 0.08-0.76, p = 0.015). CONCLUSION: These two cytokines genes polymorphisms are associated with active TB susceptibility in the Algerian population. They act synergistically in terms of protection and susceptibility regarding the two forms of the disease. Moreover, these associations were more marked among males suggesting a potential role of gender.
