Mycobacterial adenitis: role of <i>Mycobacterium bovis</i>, non-tuberculous mycobacteria, HIV infection, and risk factors in Arusha, Tanzania

Abstract

Objective: To assess risk factors and mycobacterial agents in mycobacterial adenitis. Design: Cross sectional involving comparison analysis of high-risk groups. Setting: Seven hospitals in rural and semi-rural districts of Arusha. Subjects: The study comprised of 457 patients of clinically diagnosed mycobacterial adenitis. Interventions: Biopsy materials were cultured and identification of mycobacterial isolates, and HIV infection testing were performed using standard methods. A questionnaire was used to establish information for assessing risk factors. Main outcome measures: Proportions of mycobacterial isolates, risk factors and odds ratios. Results: Of the 457 specimens, 65(14.2%) were culture positive. Isolates identified were M. bovis, 7(10.8%) M. tuberculosis, 27(41.5%) and non-tuberculous mycobacteria 31(47.7%). HIV infection and ingestion of raw milk were linked with increased risk of M. bovis infection by OR of 13.6 (95% CI, 1.7-109.9) and 15.28 (3.26-71.7), respectively. On multivariate analysis, an OR of 16.2 (1.3-201.3) for having M. bovis adenitis was linked to HIV infection, raw milk and houses with poor ventilation. An OR of 5.2 (1.2-20.6) for non-tuberculous mycobacterial adenitis was linked to history of TB in the family, HIV infection, raw milk, raw animal products and poor knowledge on transmission of tuberculosis. Conclusions: M. bovis caused one out of ten cases of culture positive mycobacterial adenitis. Non-tuberculous mycobacteria were more common than M. tuberculosis (50% and 40% of the cases, respectively). HIV infection and raw animal products are among the risk factors identified for M. bovis and non-tuberculous mycobacterial adenitis.

Head and neck mycobacterial infections in pediatric patients

“…The subject's immunogical reactivity is very important in case of mycobacterial lymphadenopathy: the severity of mycobacterial lymphoadenitis in HIV positive patients is extensively described in the literature [13,14].…”

Immunohistochemistry using a Mycobacterium tuberculosis complex specific antibody for improved diagnosis of tuberculous lymphadenitis

“…34 An epidemiological study from Tanzania, where these samples were taken, showed that half of the culture positive cases were caused by non-tuberculous mycobacteria and that they were as common as M. tuberculosis in granulomatous lymph adenitis. 8 In recent years, environmental mycobacterial disease have become particularly relevant to human health, due to their high prevalence in HIVcoinfected patients. 35 Considering these facts, infection with non-tuberculous mycobacteria is a public health issue, making it important to differentiate between mycobacterial species in granulomatous infections.…”

“…Furthermore, culture is positive in only a fraction of lymphadenitis cases. 8 Low culture positivity in extrapulmonary tuberculosis is well known and represents a general problem. This makes it problematic to use culture results as a gold standard for a test that is validated for paucibacillary tuberculosis lymphadenitis cases.…”

“…5 However, a substantial number of cases of granulomatous lymphadenitis are caused by non-tuberculous mycobacteria, especially in countries with high prevalence of these mycobacteria. [6][7][8] Diagnosis of tuberculous lymphadenitis is a challenge. The clinical criteria used for diagnosis have poor sensitivity and specificity and may lead to over-diagnosis, especially in countries with high endemic rates of tuberculosis.…”

A review of bovine tuberculosis at the wildlife–livestock–human interface in sub-Saharan Africa

“…2; adapted from [33,53,[77][78][79][80][81]) include the type of production system (intensive, dairy farms, use of upgraded B. taurus breeds), animal movements (herds importing animals, transhumance) and absence or inefficiency of bTB surveillance and control. Several studies have analysed bTB risks of transmission between livestock and humans [58,67,75,80,82], identifying husbandry practices (housing, mixing cattle herds with other small ruminants), food preferences (consumption of raw or soured milk) and overall health and hygienic conditions (HIV) as the main risk factors for humans (Fig. 2).…”