Prevalence of pulmonary tuberculosis and HIV infections and risk factors associated to tuberculosis in detained persons in Antananarivo, Madagascar

The incidence rate of tuberculosis in prisons is estimated to be 8 times greater than that in the general population in Madagascar. Our objectives were to estimate the prevalence of pulmonary tuberculosis and HIV infection among prisoners and to identify risk factors associated with tuberculosis. We conducted a cross-sectional study at the central prison of Antananarivo from March to July 2021. Individual male and female inmates aged ≥ 13 years who had lived in the prison for at least three months prior to the study period were included as participants. Acid-fast bacilli detection by microscopy and/or culture, an intradermal tuberculin test, a chest X-ray, and a rapid diagnostic orientation test for HIV were performed. Among 748 participants, 4 (0.5%) were confirmed to have pulmonary tuberculosis. Overall, 14 (1.9%) patients had "confirmed" or "probable" tuberculosis [0.90-2.84, 95% CI]. The proportion of participants with latent tuberculosis infection was 69.6% (517/743) based on a positive tuberculin test without clinical symptoms or radiography images indicating tuberculosis. Out of 745 HIV screening tests, three showed reactive results (0.4%). Age (OR = 4.4, 95% CI [1.4-14.0]) and prior tuberculosis treatment (or episodes) were found to be associated with confirmed and probable tuberculosis.

Tuberculosis and HIV’s management: A health seeking behaviour Analysis of Incarcerated Patients

Madagascar has about 23.000 prisoners detained in 44 prisons. In prisons, tuberculosis (TB) prevalence is eight times higher than in the general population due to different conditions that make them vulnerable like overcrowded conditions. HIV prevalence may also be higher than in the general population due to risky practices that may expose prisoners to HIV infection, but no precise data are available. Though the national strategic plans for TB, HIV or TB-HIV co-infection' management mention prisoners as one of their target populations, any specific care are provided for these incarcerated patients. They then face many difficulties in their care specifically HIV carriers.

An anthropological study dealing with the care pathway of TB and HIV patients in prison is on-going. The aim of our study is to analyse and understand the care seeking pathway of prisoners with TB and/or HIV'. Interviews are conducted at the main prisons of Antananarivo, Mahajanga and Manakara. A total of sixty interviews will be conducted with prisoners (with TB and/or HIV) and other persons such as nurses, reference doctors, prison officers. Focus groups were also conducted with prisoners in order to understand the care seeking pathway in prison and also detainees' perception of TB and HIV.

Data collection is on-going and will be finished in May 2020. These preliminary findings revealed that there is an informal hierarchy to be respected for access to care. The power relations between detainees give unequal access to care. It is also conditioned by others circumstances like coinage or social status. It was also revealed that the level of detainees' knowledge of diseases TB and HIV remains limited to the modes of transmission. Interviews revealed any stigmatization of patients with TB or HIV.

Data are being collected and recommendations will follow. Yet, we can already claim that the prevention of both TB and HIV needs to be strengthened.

Key messages

Our study will provide a better understanding of the detainees’ issues the management of TB and/or HIV. Our analysis would propose concrete recommendations to improve health care and cure in prisons.

The HLA-B landscape of Africa: Signatures of pathogen-driven selection and molecular identification of candidate alleles to malaria protection

Human leukocyte antigen (HLA) genes play a key role in the immune response to infectious diseases, some of which are highly prevalent in specific environments, like malaria in sub-Saharan Africa. Former case-control studies showed that one particular HLA-B allele, B*53, was associated with malaria protection in Gambia, but this hypothesis was not tested so far within a population genetics framework. In this study, our objective was to assess whether pathogen-driven selection associated with malaria contributed to shape the HLA-B genetic landscape of Africa. To that aim, we first typed the HLA-A and -B loci in 484 individuals from 11 populations living in different environments across the Sahel, and we analysed these data together with those available for 29 other populations using several approaches including linear modelling on various genetic, geographic and environmental parameters. In addition to relevant signatures of populations' demography and migrations history in the genetic differentiation patterns of both HLA-A and -B loci, we found that the frequencies of three HLA alleles, B*53, B*78 and A*74, were significantly associated with Plasmodium falciparum malaria prevalence, suggesting their increase through pathogen-driven selection in malaria-endemic environments. The two HLA-B alleles were further identified, by high-throughput sequencing, as B*53:01:01 (in putative linkage disequilibrium with one HLA-C allele, C*04:01:01:01) and B*78:01 in all but one individuals tested, making them appropriate candidates to malaria protection. These results highlight the role of environmental factors in the evolution of the HLA polymorphism and open key perspectives for functional studies focusing on HLA peptide-binding properties.

Photofoams: remote control of foam destabilization by exposure to light using an azobenzene surfactant

We report evidence for photocontrolled stability and breakage of aqueous foams made from solutions of a cationic azobenzene-containing surfactant over a wide range of concentrations. Exposure to UV or visible lights results in shape and polarity switches in the surfactant molecule, which in turn affects several properties including critical micelle concentration, equilibrium surface tension, and the air-water interfacial composition (cis isomers are displaced by trans ones). We demonstrate that the trans isomer stabilizes foams, whereas the cis isomer forms unstable foams, a property that does not correlate with effects of light on surface tension, nor with total surfactant concentration. Achieving in situ breakage of foam is accordingly ascribed to the remote control of the dynamics of adsorption/desorption of the surfactant, accompanied by gradients of concentrations out of equilibrium. Photomodulation of adsorption kinetics and/or diffusion dynamics on interfaces is reached here by a noninvasive clean trigger, bringing a new tool for the study of foams.

[The three-dimensional spiral scanner and volume rendering technique: importance in craniofacial traumatology and reconstructive surgery]

There are two reconstruction methods for 3D imaging with a helical scanner: a surface rendering process providing a 3D-SSD (Surface Shaded Display) image that looks like a plaster cast skull and 3D-VRD (Volume Rendering Technique) which is more precise and gives 3D images similar to radiographs. We review briefly the techniques used to acquire these images and present 3D volume-rendering scanners, pointing out its usefulness in craniomaxillofacial traumatology and reconstructive surgery.

Summary of track D: social science: research, policy and action

SCOPE

This review summarizes the main issues discussed during Track D, which examined the societal impact of HIV/AIDS, and responses to the epidemic by individuals, families, communities and societies worldwide. Micro- and macrolevel issues addressed included the development, implementation and evaluation of programmes for prevention and care; policy development and implementation; structural issues such as the impact of gender relations, development and migration on the development of the epidemic; and the social and economic impact of HIV/AIDS on affected societies and communities.

RECURRENT THEMES

Presentations provided strong evidence that peer-led, community-based programmes offer particularly effective ways of working, and that participatory research involving affected communities provides useful results for the design and evaluation of programmes and policies. This is the case across settings, issues, populations and countries.

FUTURE DIRECTIONS

Emerging needs include how best to ensure sustainability of national and international responses, how best to scale up successful interventions for wider reach, and how best to work with systematically marginalized, neglected groups and populations. Research priorities include the characterization of the multiple determinants of HIV-related vulnerability, and the evaluation of interventions that take these complex determinants as their starting point. A more coherent and strategic response requires less separation between the different constituencies involved in AIDS work, and the more sustained involvement of people living with HIV/AIDS themselves.