Serial Mass Screening for Tuberculosis among Incarcerated Persons in Brazil.

BACKGROUND: Active search for tuberculosis cases through mass screening is widely described as a tool to improve case detection in hyperendemic settings. However, its effectiveness in high-risk populations, such as incarcerated people, is debated. METHODS: Between 2017 and 2021, three rounds of mass screening were carried out in three Brazilian prisons. Social and health questionnaires, chest X-rays and Xpert MTB/RIF were performed. RESULTS: Over 80% of the prison population was screened. Overall, 684 cases of pulmonary tuberculosis were diagnosed. Prevalence across screening rounds was not statistically different. Among incarcerated persons with symptoms, the overall prevalence of tuberculosis per 100,000 persons was 8,497 (95% CI, 7,346-9,811), 11,115 (95% CI, 9,471-13,082), and 7,957 (95% CI, 6,380-9,882) in screening rounds one, two and three, respectively. Similar to our overall results, there were no statistical differences between screening rounds and within individual prisons. We found no statistical differences in CAD4TB scores across screening rounds among people with tuberculosis - the median scores in rounds 1, 2, and 3 were 82 (IQR, 63-97), 77 (IQR, 60-94), and 81 (IQR, 67-92), respectively. CONCLUSIONS: In this environment with hyperendemic rates of tuberculosis, three rounds of mass screening did not reduce the overall tuberculosis burden. In prisons, where a substantial amount of TB is undiagnosed annually, a range of complementary interventions and more frequent TB screening may be required.

The role of prisons in disseminating tuberculosis in Brazil: A genomic epidemiology study.

Background: Globally, prisons are high-incidence settings for tuberculosis. Yet the role of prisons as reservoirs of M. tuberculosis, propagating epidemics through spillover to surrounding communities, has been difficult to measure directly. Methods: To quantify the role of prisons in driving wider community M. tuberculosis transmission, we conducted prospective genomic surveillance in Central West Brazil from 2014 to 2019. We whole genome sequenced 1152 M. tuberculosis isolates collected during active and passive surveillance inside and outside prisons and linked genomes to detailed incarceration histories. We applied multiple phylogenetic and genomic clustering approaches and inferred timed transmission trees. Findings: M. tuberculosis sequences from incarcerated and non-incarcerated people were closely related in a maximum likelihood phylogeny. The majority (70.8%; 46/65) of genomic clusters including people with no incarceration history also included individuals with a recent history of incarceration. Among cases in individuals with no incarceration history, 50.6% (162/320) were in clusters that included individuals with recent incarceration history, suggesting that transmission chains often span prisons and communities. We identified a minimum of 18 highly probable spillover events, M. tuberculosis transmission from people with a recent incarceration history to people with no prior history of incarceration, occurring in the state's four largest cities and across sampling years. We additionally found that frequent transfers of people between the state's prisons creates a highly connected prison network that likely disseminates M. tuberculosis across the state. Interpretation: We developed a framework for measuring spillover from high-incidence environments to surrounding communities by integrating genomic and spatial information. Our findings indicate that, in this setting, prisons serve not only as disease reservoirs, but also disseminate M. tuberculosis across highly connected prison networks, both amplifying and propagating M. tuberculosis risk in surrounding communities. Funding: Brazil's National Council for Scientific and Technological Development and US National Institutes of Health.

B-1 lymphocytes differentiate into functional osteoclast-like cells.

The existence of murine peritoneal osteoclast precursors has been already described. Also, recent reports evidenced an interplay between B lymphocytes and osteoclasts development. B-1 cells comprise a B-lymphocyte subset that resides mostly in pleural and peritoneal cavities. It has been demonstrated that B-1 cells can differentiate into mononuclear phagocytes and form multinucleated giant cells. Based on these findings, we investigated the role of B-1 lymphocytes in bone resorption and osteoclastogenesis. In vivo experimental periodontitis induced in B-1 deficient Xid mice demonstrated that bone resorption is impaired in these animals. However, reconstitution of Xid mice with B-1 cells increased bone resorption to near Balb/c values. B-1 cell derived phagocytes express the receptor activator of nuclear factor-κB (RANK) and the macrophage colony-stimulating factor receptor (M-CSFR). When cultured with RANK-ligand (RANKL) and M-CSF, B-1 cells became tartrate resistant acid phosphatase (TRAP) positive multinucleated cells, a typical osteoclast phenotype. Lacunae formation was observed when cells were cultivated onto a calcium phosphate analog, indicating functional differentiation of B1 cells into osteoclast-like cells. The dynamics of their IgM expression showed that this lymphoid marker was downregulated along the differentiation of B-1 lymphocytes into osteoclasts. Our results unveiled the first evidence that B-1 cells have a role in osteoclastogenesis and bone resorption and offer new insights in the relationship between bone and lymphoid cells.

Release of cytokines by stimulated peripheral blood mononuclear cells in chronic periodontitis.

OBJECTIVE: The emergence of periodontal medicine increased interest in defining the behaviour of peripheral blood cells in periodontitis subjects in comparison with healthy group. The aim of this study was to evaluate the levels of interleukin (IL)-8, tumour necrosis factor-α (TNF-α), IL-6 and IL-10 released by Escherichia coli lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC) obtained from the peripheral blood of chronic periodontitis subjects. DESIGN: PBMC samples were isolated from 19 systemically healthy donors, divided into generalized chronic periodontitis (n=10) and healthy (n=9) subjects. Cells were incubated for 24-48 h in 500 µL wells containing RPMI 1640 and stimulated with 1.0 ng/mL of E. coli LPS. Supernatants were used to quantify the amounts of IL-8, TNF-α, IL-6 and IL-10 released using enzyme-linked immunosorbent assay (ELISA). RESULTS: PBMC cells from periodontitis subjects released higher levels of TNF-α and IL-6 than those from healthy subjects (P<0.05). Conversely, the supernatants of the stimulated PBMC cells obtained from healthy subjects presented higher amounts of IL-8 than those from periodontitis (P<0.05). No differences were observed in the levels of IL-10 (P>0.05) between groups. CONCLUSION: In conclusion, the results of the present study showed that E. coli LPS-stimulated PBMC from subjects with periodontitis present a different pattern of cytokine release when compared to PBMC from healthy subjects. This phenomenon could have implications locally, in periodontitis, as well as in systemic diseases.

Assessment of bone repair associated with the use of organic bovine bone and membrane irradiated at 830 nm.

OBJECTIVE: The aim of the present investigation was to assess histologically the effect of LLLT (GaAIAs, 830 nm, 40 mW, CW, (Phi) approximately 0.6 mm, 16 J/cm(2) per session) on the repair of surgical defects created in the femur of the Wistar Albinus rat. The defects were filled to lyophilized bovine bone (Gen-ox), organic matrix) associated or not to GTR (Gen-derm). BACKGROUND DATA: A major problem on modern Dentistry is the recovery of bone defects caused by trauma, surgical procedures or pathologies. Several types of biomaterials have been used in order to improve the repair of these defects. These materials are often associated to procedures of GTR. Previous studies have shown positive effects of LLLT on the repair of soft tissue wounds, but there are a few on its effects on bone healing. METHODS: Surgical bone defects were created in 42 animals divided into five groups: Group I (control, 6 animals); Group II (Gen-ox, 9 animals); Group III (Gen-ox + Laser, 9 animals); Group IV (Gen-ox + Gen-derm, 9 animals); Group V (Gen-ox + Gen-derm + Laser, 9 animals). The animals on the irradiated group received 16 J/cm(2) per session divided into four points around the defect (4 J/cm(2)) being the first irradiation immediately after surgery and repeated seven times at every 48 h. The animals were humanly killed after 15, 21, and 30 days. RESULTS: The results of the present investigation showed histological evidence of improved amount of collagen fibers at early stages of the bone healing (15 days) and increased amount of well organized bone trabeculae at the end of the experimental period (30 days) on irradiated animals compared to non irradiated ones. CONCLUSIONS: It is concluded that a positive biomodulative effect on the healing process of one defect associated or not to the use of organic lyophilized bone and biological bovine lyophilized membrane on the femur of the rat.

Effect of 830-nm laser light on the repair of bone defects grafted with inorganic bovine bone and decalcified cortical osseus membrane.

OBJECTIVE: The aim of this study was to histologically assess the effect of low-level laser therapy (LLLT) (lambda830 nm) on the repair of standardized bone defects of the femur of Wistar albinus rats grafted with inorganic bovine bone and associated (or not) with decalcified bovine cortical bone membrane. BACKGROUND DATA: Bone loss may be a result of pathology, trauma, or surgical procedure. Extensive studies on the process of bone repair have been undertaken, and several techniques for the correction of bone defects have been proposed. Amongst them is the use of several types of grafts, the use of membranes, and the combination of both techniques. There is evidence in the literature of the positive effect of LLLT on the healing of soft tissue wounds. However, its effect on bone healing is not completely understood. MATERIALS AND METHODS: Five randomized groups were studied: group I (control); group IIA (Gen-ox); group IIB (Gen-ox + LLLT); group IIIA (Gen-ox + Gen-derm); and group IIIB (Gen-ox + Gen-derm + LLLT). Bone defects were created at the femur and were treated according to the group. The animals of irradiated groups were irradiated every 48 h for 15 days; the first irradiation was performed immediately after the procedure. The animals were irradiated transcutaneuosly at four points around the defect. At each point, a dose of 4 J/cm2 was given (phi approximately equal to 0.6 mm, 40 mW), and the total dose per session was 16 J/cm2. The animals were humanely killed at 15, 21, and 30 days after surgery. The specimens were routinely processed to wax, serially cut, stained with H&E and Picrosirius stains, and analyzed under light microscopy. RESULTS: The results showed more advanced repair of the irradiated groups when compared to the non-irradiated ones. The repair of the irradiated group was characterized by both increased bone formation and on the amount of collagen fibers around the graft within the cavity, as early as the 15th day after surgery, considering the osteoconductive capacity of the Gen-ox and the increment of the cortical repair in specimens with Gen-derm membrane. CONCLUSION: It is concluded that LLLT had a positive effect on the repair of bone defect by graft associated or not with the use of biological membrane.