Tuberculosis in goats in Benoue area of North Cameroon: Prevalence, diagnostic performance of intradermal tuberculin skin test and zoonotic risk factors

Tuberculosis (TB) due to Mycobacterium bovis is a wasting disease of animals with severe public health significance. Though widely diagnosed in cattle and the performance of Tuberculin Skin Test (TST) at different cut-off points compared in various environmental conditions, there is dearth of information with respect to TB in goats in Cameroon. This study estimated the prevalence of bovine TB in goats in Benuoe area of Cameroon, based on the performance of TST against detection of tuberculous-like lesions and acid-fast bacilli as gold tests. The study detected goat TB based on tuberculous-like lesions (27.87%), acid-fast bacilli (3.29%); and bovine TB positive reactions (12.28%, 95%CI: 9.19–15.95), (8.95%, 95%CI: 6.31–12.23) and (5.37%, 95%CI: 3.36–8.09) at Single intradermal cervical tuberculin (SICT) ≥2.5mm, ≥3mm, and ≥4mm and (2.30%, 95%CI: 1.06–4.32), (1.79%, 95%CI: 0.72–3.65) and (1.02%, 95%CI: 0.28– 2.60) at Single intradermal comparative cervical tuberculin (SICCT) ≥2mm, ≥3mm, and ≥4mm cut-off points, respectively. SICT and SICCT sensitivity (11.76%) against detection of tuberculous-like lesions was significantly lower [p<0.05] with slight agreements [Kappa=0.161] compared to sensitivity (100%) and perfect agreements [Kappa=1.00] against detection of acid-fast bacilli at these cut-offs. The Bayesian model revealed a goat TB prevalence of 18.41% (95%CI: 11.73–27.00) using SICT and 4.28 (95%CI: 1.26–8.60) using SICCT with the performance characteristic being higher for SICT than SICCT at ≥2mm cut-off. However, two-graph ROC (TG-ROC) analysis revealed that the optimal goat TB diagnosis with SICCT was at ≥2mm cut-off point. Many goat handlers were aware of health hazards of zoonotic TB but ignorant about goat TB and its possible zoonotic transmission to humans. The study reports the first comparative tuberculin skin test of goats in Benoue area of North-Cameroon and confirmed that zoonotic TB is a neglected health and production problem of goats in Cameroon that needs further investigated.

PREVALENCE OF MYCOBACTERIUM TUBERCULOSIS AMONG CHILDREN AT THE RESERVOIRS OF INFECTION IN THE REPUBLIC OF TAJIKISTAN

To study the prevalence of Mycobacterium tuberculosis at the infection reservoirs in the Republic of Tajikistan among children and the impact of BCG vaccination assessed by tuberculin skin test.

Prevalence and risk factors for latent tuberculosis in polish healthcare workers: the comparison of tuberculin skin test and interferon-gamma release assay (IGRA) performance

Background Tuberculosis (TB) is still one of the most common infectious diseases worldwide. Health care workers (HCW) are at particular risk of the disease due to their constant exposure to TB patients or their specimens, nevertheless no specific surveillance is widely recommended in this group of professionals. Both, tuberculin skin test (TST) and interferon-gamma-release-assays (IGRAs) are widely applied to detect latent tuberculosis infection (LTBI). The aim of the present study was to evaluate the prevalence and risks of LTBI in the population of Polish HCW, to identify factors associated with LTBI, as well as to determine the rate of the discordance between the results of the two applied tests in relation to various factors in a TB endemic setting. The study participants were recruited from several health care facilities (hospitals and outpatients clinics) all over the country. Laboratory personnel included 156 persons from both TB and non-TB laboratories (118 clinical pathologists, 38 laboratory technicians), 31 medical doctors, 29 nurses (from both TB and non-TB wards and from family practices), 6 other medical employees (patients assistants). Out of examined group 88 (40%) declared constant (everyday) occupational contact with TB patients and/or contagious biologic materials, 134 (60%) reported sporadic (incidental) contact (few times a year). Administrative HCWs who were not in direct contact with patients were not included in the study group. Material and methods LTBI status was prospectively evaluated in 222 HCW, 204 females, 18 males, aged 40.8 ± 9 years, with tuberculin skin test (TST) and interferon gamma release assay (QuantiFERON-TB-Gold in Tube – QFT GIT). Results TST ≥ 10 mm was found in 58% of HCW, QFT GIT ≥ 0.35 IU/ml in 23%. Nevertheless the relative number of positive QFT GIT in HCW above 45 years of age exceeded those obtained in general population (prevalence of positive QTF test in polish adult population is around 23%). The risk of obtaining positive QFT GIT was significantly increased in the participants older than 44 years (OR = 4.95, 95%CI:2.375–10.193), in those employed > 10 years (OR = 2.726, 95%CI:1.126–6.599), and in those who reported the direct contact with tuberculous patients or infected biological materials (OR = 8.135, 95%CI:1.297–51.016). The concordance between TST and IGRA was poor (kappa 0.23), especially in younger participants, possibly due to BCG vaccination in childhood. Conclusion The increased risk of LTBI in Polish HCW was related to age, duration of employment and contact with infectious patients or their biological specimens. TB infection control measures in health care facilities in Poland are still insufficient. It is crucial to increase awareness about the importance of detecting and treating LTBI of HCW.