The social determinants of tuberculosis and their association with TB/HIV co-infection in Lusaka, Zambia

Introduction: Tuberculosis (TB) is a major public health problem globally.Progress made in TB control through the implementation of the DOTS strategy, has been retarded by factors such as poverty, the HIV pandemic and the advent of multidrug resistant tuberculosis. There is currently an increasing shift in TB control strategies to emphasize the importance of social determinants of TB if notable impact has to be attained. However, limited data exist that describe these determinants in high burden settings such as Zambia. This study was conducted to explore the social determinants of TB and their association with TB/HIV co-infection, in order to inform TB control strategies that would lead to appropriate action for impact.Method: A cross-section study of TB patients presenting to four peri-urban health facilities in Lusaka through administration of a standard structured questionnaire. STATA 12 Version 1 was used for analysis.Results: There were 1,259 TB patients enrolled. The median age was 35 (IQR; 29 – 41). The main determinants that were associated with TB/HIV co-infection were: being in the age-group 24-49 (p = 0.0001); being female (p = 0.0001); re-treatment (p = 0.0001); having extrapulmonary TB (p = 0.02); being married or widowed (p = 0.05 and p = 0.01, respectively)Conclusions: Describing the social determinants of TB and their association with TB/HIV co-infection highlighted a number of opportunities to strengthen control beyond the Stop TB Strategy

Tuberculosis among older adults in Zambia: Burden and characteristics among a neglected group

BACKGROUND: The 2010 Global Burden of Disease estimates show that 57% of all TB deaths globally occurred among adults older than 50 years of age. Few studies document the TB burden among older adults in Southern Africa. We focused on adults older than 55 years to assess the relative TB burden and associated demographic factors. METHODS: A cross sectional nationally representative TB prevalence survey conducted of Zambian residents aged 15 years and above from 66 clusters across all the 10 provinces of Zambia. Evaluation included testing for TB as well as an in-depth questionnaire. We compared survey data for those aged 55 and older to those aged 15-54 years. Survey results were also compared with 2013 routinely collected programmatic notification data to generate future hypotheses regarding active and passive case finding. RESULTS: Among older adults with TB, 30/ 54 (55.6%) were male, 3/27 (11.1%) were HIV infected and 35/54 (64.8%) lived in rural areas. TB prevalence was higher in those aged ≥55 (0.7%) than in the 15-54 age group (0.5%). Males had higher rates of TB across both age groups with 0.7% (15-54) and 1.0% (≥55) compared with females 0.4% (15-54) and 0.6% (≥55). In rural areas, the prevalence of TB was significantly higher among older than younger adults (0.7% vs 0.3%), while the HIV infection rate was among TB patients was lower (11.1% vs 30.8%). The prevalence survey detected TB in 54/7484 (0.7%) of older adults compared to 3619/723,000 (0.5% ) reported in 2013 programmatic data. CONCLUSION: High TB rates among older adults in TB endemic areas justify consideration of active TB case finding and prevention strategies

Advancing new diagnostic tests for latent tuberculosis infection due to multidrug-resistant strains of Mycobacterium tuberculosis - End of the road?

An estimated 1.8 billion people worldwide have a latent tuberculosis infection (LTBI), with wide variations in LTBI rates across countries. LTBI can be due to infection with either drug-sensitive or drug-resistant Mycobacterium tuberculosis (Mtb) strains. Accurate data on the prevalence of LTBI due to multidrug-resistant (MDR) Mtb strains are unavailable, since the strains cannot be isolated for resistance testing. There are no 'gold standard' tests for accurately diagnosing LTBI. Only three tests are currently available and approved by the World Health Organization (WHO) for the diagnosis of LTBI: the now outdated tuberculin skin test (TST), developed a century year ago, and the two interferon-gamma release assays (IGRAs) developed and rolled out over the past decade, the QuantiFERON (Qiagen, Germany) and T-SPOT.TB (Oxford Immunotec, United Kingdom) tests. These latter tests are not ideal due to issues of sensitivity, specificity, inability to distinguish infection with MDR-Mtb strains, and high costs. Achieving the WHO End TB Strategy target of an 80% reduction in global TB incidence by 2030 will require a major reduction in the number of persons with LTBI progressing to active TB disease. Critical to this will be the development of new diagnostic tests that are better than currently available LTBI tests at predicting who is at risk of progression to active TB disease. The diagnostic product development portfolio for LTBI appears to have reached the end of the road. Every attempt to make optimal use of currently available IGRAs using WHO LTBI guidelines for LTBI testing and treatment must be made to achieve WHO End TB strategy targets

Multidrug-resistant TB in Zambia: review of national data from 2000 to 2011

Multidrug-resistant tuberculosis (MDR-TB) is posing a great threat to global TB control. The burden in Zambia is not well defined because routine surveillance data are scarce. We reviewed national MDR-TB data for the last decade to inform future public health policy with respect to MDR-TB in Zambia

Minimizing the impact of the triple burden of COVID-19, tuberculosis and HIV on health services in sub-Saharan Africa

In this perspective, we discuss the impact of COVID-19 on tuberculosis (TB)/HIV health services and approaches to mitigating the growing burden of these three colliding epidemics in sub-Saharan Africa (SSA). SSA countries bear significantly high proportions of TB and HIV cases reported worldwide, compared to countries in the West. Whilst COVID-19 epidemiology appears to vary across Africa, most countries in this region have reported relatively lower-case counts compared to the West. Nevertheless, the COVID-19 pandemic has added an additional burden to already overstretched health systems in SSA, which, among other things, have been focused on the longstanding dual epidemics of TB and HIV. As with these dual epidemics, inadequate resources and poor case identification and reporting may be contributing to underestimations of the COVID-19 case burden in SSA. Modelling studies predict that the pandemic-related disruptions in TB and HIV services will result in significant increases in associated morbidity and mortality over the next five years. Furthermore, limited empirical evidence suggests that SARS-CoV-2 coinfections with TB and HIV are associated with increased mortality risk in SSA. However, predictive models require a better evidence-base to accurately define the impact of COVID-19, not only on communicable diseases such as TB and HIV, but on non-communicable disease comorbidities. Further research is needed to assess morbidity and mortality data among both adults and children across the African continent, paying attention to geographic disparities, as well as the clinical and socio-economic determinants of COVID-19 in the setting of TB and/or HIV

Incidental Tuberculosis in sudden, unexpected, and violent deaths in the community Lusaka, Zambia - A descriptive forensic post-mortem examination study

Objectives: Tuberculosis remains a global emergency. In Zambia only 55% of tuberculosis cases are diagnosed. We performed a study to determine incidental cases of tuberculosis seen at forensic autopsy of individuals who died suddenly and unexpectedly in the community in Lusaka, Zambia. Methods: Whole-body autopsies were performed according to Standard Operating Procedures. Representative samples obtained from relevant organs were subjected to pathological examination. Information on circumstances surrounding the death was obtained. Data on patient demographics, gross and microscopic pathological findings, and cause(s) of death were analysed. Results: Incidental tuberculosis was found in 52 cases (45 male, 7 female, age range 14-66) out of 4286 whole-body autopsies. 41/52 (80%) were aged 21-50 years. One was a 14-year old boy who died during a football match. 39/52 (75%) deaths were attributable specifically to tuberculosis only. Other deaths were due to acute alcohol intoxication(4), violence(7), ruptured ectopic pregnancy(1), bacterial meningitis (1). All the cases were from poor socio-economic backgrounds and lived in high-density areas of Lusaka. Conclusions: Incidental cases of active tuberculosis undiagnosed antemortem seen at forensic autopsy reflects major gaps in the national TB control programs. More investments into proactive screening, testing, treatment activities, and accurate data collection are required

Cardiac Cysticercosis and Neuro Cysticercosis in Sudden and Unexpected Community Deaths in Lusaka, Zambia – A Descriptive Medico-Legal Post-Mortem Examination Study

Background: Cysticercosis is a World Health Organization designated neglected human zoonosis worldwide. Data on cardiac cysticercosis and its contribution to sudden and unexpected community deaths are scarce and require study. Methods: A study was performed of cysticercosis-related deaths and other incidental cases of cysticercosis seen at forensic post-mortem examination over a period of 12 months, in individuals who died suddenly and unexpectedly in the community in Lusaka, Zambia. Whole-body post-mortem examinations were performed according to standard operating procedures for post-mortem examinations. Representative samples were obtained from all body organs and subjected to histopathological examination. Information was obtained on circumstances surrounding the death. Data were collated on patient demographics, history, co-morbidities, pathological gross and microscopic findings, and forensic autopsy cause(s) of death. The available literature on cardiac cysticercosis was also reviewed. Results: Nine cases of cysticercosis were identified. Eight of the nine cases had cardiac cysticercosis. There was no prior history of cysticercosis before death. All were male, aged between 28 and 56 years, and from high population density and low socioeconomic communities. There was no community case clustering identified. Conclusions: Cardiac cysticercosis and neurocysticercosis are important incidental findings in sudden and unexpected deaths in the community and can easily be missed antemortem. More investment in forensic autopsy services is required to define the undiagnosed burden of deaths due to treatable communicable diseases