A four-year trend in pulmonary bacteriologically confirmed tuberculosis case detection in Kampala-Uganda

Incidence and risk factors for tuberculosis at a rural HIV clinic in Uganda, 2012-2019; A retrospective cohort study

BACKGROUND

Tuberculosis (TB) is the leading cause of death among people living with HIV (PLHIV). Antiretroviral therapy (ART) initiation lowers the risk of HIV-associated TB. Earlier studies have shown TB incidence to be high in the first year of ART. We undertook a study to (1) assess the incidence of TB and (2) associated factors among persons initiating ART in a rural cohort.

METHODS

We conducted a retrospective cohort analysis study among PLHIV aged ≥ 18 years, initiated on ART from January 1, 2012, to December 31, 2019, and TB disease-free at the time of ART initiation, at Kalisizo ART clinic. TB disease incidence was calculated by dividing the number of new TB cases by the total follow-up time expressed per 100 person-years among persons followed up until the date of incident TB disease, loss to follow-up, transfer out, death or censored at the end of the study; whichever occurred first. Factors associated with TB disease incidence were assessed in the multivariable analysis by Poisson regression analysis at 5% significance level.

RESULTS

For the period 2012 to 2019, 2,589 PLHIV were initiated on ART; 57% (1,470/2,589) were female. Females were more likely to be aged below 35 years while males were more likely to be aged 25-44 years (p < 0.001). Eighty-seven per cent (1,269/1,470) of females compared to 78% (866/1,119) of males were in WHO clinical stage 1 (p < 0.001). Sixty-one TB disease events were observed in 7,363 person-years. The overall TB disease incidence was 0.83 (95% CI: 0.63-1.06) per 100 person-years. Males were more likely than females to develop TB disease, adjusted incidence rate ratio (adj IRR) 2.13 (95% CI: 1.27-3.57) per 100 person-years, p = 0.004. Compared to using ART for 0-5 months, time on ART was associated with a lower TB incidence rate at 6-12 months, 13-24 months, > 24 months (adj IRR 0.20 (95% CI: 0.09-0.46), 0.14 (95% CI: 0.06-0.33), 0.16 (95% CI: 0.08-0.31) p < 0.001 respectively).

CONCLUSIONS AND RECOMMENDATIONS

Incidence of TB among PLHIV on ART was low in this rural population. Clinicians offering care to people with HIV in the rural setting should have a heightened index of suspicion for TB disease.

Level of tuberculosis-related stigma and associated factors in Ugandan communities

Tuberculosis (TB) stigma remains a significant barrier to TB control efforts globally, especially in countries with a high TB burden. Studies about TB stigma done in Uganda so far have been limited in scope and focused on data collected health facilities. In this study we report TB related stigma at community level for the period 2021/2022. We used the 2021/22 Lot Quality Assurance Sampling (LQAS) data from a sample of 33,349 participants across 77 districts, to measure TB stigma determine factors associated. We included demographic characteristics, knowledge and participant perspectives as our study variables. Univariable and multivariate logistic regression analyses were performed to identify factors associated with TB stigma. TB stigma was assessed as a categorical variable (below or above the median) due to the skewness of the data when fitting the scores. The data set had equal proportions of males and females. The largest age group was 20-29 years old (38.47%). Most participants were married (62.94%) and had primary level education (65.80%). The TB stigma scores were assigned on a scale from 0 to 30, with an average score of 21.67 (±8.22) and a median score of 24 (19-28). Overall, 45.48% of participants had TB stigma scores above the median. Variations in TB stigma levels were observed across different districts. Factors associated with higher TB stigma included older age, higher education levels, urban residence, and TB knowledge. To reduce TB stigma and misinformation that can make an impact on TB response, community interventions should balance increasing awareness with minimizing fear. These interventions should be well-rounded and context-specific to address disparities within communities and bolster TB control efforts in the country.

Mapping TB incidence across districts in Uganda to inform health program activities

BACKGROUND

Identifying spatial variation in TB burden can help national TB programs effectively allocate resources to reach and treat all people with TB. However, data limitations pose challenges for subnational TB burden estimation.

METHODS

We developed a small-area modeling approach using geo-positioned prevalence survey data, case notifications, and geospatial covariates to simultaneously estimate spatial variation in TB incidence and case notification completeness across districts in Uganda from 2016-2019. TB incidence was estimated using 1) cluster-level data from the national 2014-2015 TB prevalence survey transformed to incidence, and 2) case notifications adjusted for geospatial covariates of health system access. The case notification completeness surface was fit jointly using observed case notifications and estimated incidence.

RESULTS

Estimated pulmonary TB incidence among adults varied >10-fold across Ugandan districts in 2019. Case detection increased nationwide from 2016 to 2019, and the number of districts with case detection rates >70% quadrupled. District-level estimates of TB incidence were five times more precise than a model using TB prevalence survey data alone.

CONCLUSION

A joint spatial modeling approach provides useful insights for TB program operation, outlining areas where TB incidence estimates are highest and health programs should concentrate their efforts. This approach can be applied in many countries with high TB burden.

Trends of notification rates and treatment outcomes of tuberculosis cases with and without HIV co-infection in eight rural districts of Uganda (2015 - 2019)

Background

The End TB Strategy aims to reduce new tuberculosis (TB) cases by 90% and TB-related deaths by 95% between 2015 – 2035. We determined the trend of case notification rates (CNRs) and treatment outcomes of TB cases with and without HIV co-infection in rural Uganda to provide an interim evaluation of progress towards this global target in rural settings.

Methods

We extracted retrospective programmatic data on notified TB cases and treatment outcomes from 2015 – 2019 for eight districts in rural Uganda from the District Health Information System 2. We estimated CNRs as the number of TB cases per 100,000 population. Treatment success rate (TSR) was calculated as the sum of TB cure and treatment completion for each year. Trends were estimated using the Mann–Kendall test.

Results

A total of 11,804 TB cases, of which 5,811 (49.2%) were HIV co-infected, were notified. The overall TB CNR increased by 3.7-fold from 37.7 to 141.3 cases per 100,000 population in 2015 and 2019 respectively. The increment was observed among people with HIV (from 204.7 to 730.2 per 100,000, p = 0.028) and HIV-uninfected individuals (from 19.9 to 78.7 per 100,000, p = 0.028).

There was a decline in the TSR among HIV-negative TB cases from 82.1% in 2015 to 63.9% in 2019 (p = 0.086). Conversely, there was an increase in the TSR among HIV co-infected TB cases (from 69.9% to 81.9%, p = 0.807).

Conclusion

The CNR increased among people with and without HIV while the TSR reduced among HIV-negative TB cases. There is need to refocus programs to address barriers to treatment success among HIV-negative TB cases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13111-1.

Osteopontin and malaria: no direct effect on parasite growth, but correlation with P. falciparum-specific B cells and BAFF in a malaria endemic area

Background

The dysregulation of B cell activation is prevalent during naturally acquired immunity against malaria. Osteopontin (OPN), a protein produced by various cells including B cells, is a phosphorylated glycoprotein that participates in immune regulation and has been suggested to be involved in the immune response against malaria. Here we studied the longitudinal concentrations of OPN in infants and their mothers living in Uganda, and how OPN concentrations correlated with B cell subsets specific for P. falciparum and B cell activating factor (BAFF). We also investigated the direct effect of OPN on P. falciparum in vitro.

Results

The OPN concentration was higher in the infants compared to the mothers, and OPN concentration in infants decreased from birth until 9 months. OPN concentration in infants during 9 months were independent of OPN concentrations in corresponding mothers. OPN concentrations in infants were inversely correlated with total atypical memory B cells (MBCs) as well as P. falciparum-specific atypical MBCs. There was a positive correlation between OPN and BAFF concentrations in both mothers and infants. When OPN was added to P. falciparum cultured in vitro, parasitemia was unaffected regardless of OPN concentration.

Conclusions

The concentrations of OPN in infants were higher and independent of the OPN concentrations in corresponding mothers. In vitro, OPN does not have a direct effect on P. falciparum growth. Our correlation analysis results suggest that OPN could have a role in the B cell immune response and acquisition of natural immunity against malaria.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02368-y.

Patient characteristics associated with different types of prison TB: an epidemiological analysis of 921 TB cases diagnosed at an Ethiopian prison

Background

Despite incarcerated population being at an increased risk of tuberculosis (TB) and serving as a potential source of TB transmission for the general population, prison TB remains understudied. Given its adverse impact on progress towards TB elimination, World Health Organization (WHO) has identified prison TB research as a top priority to guide TB treatment/control interventions.

Methods

We retrospectively analyzed 921 notified TB cases that were diagnosed at Kality Federal Prison, Ethiopia during 2009–2017. To assess trends of microbiologically confirmed pulmonary TB (PTB), extra-pulmonary TB (EPTB), and TB-HIV co-infection, an ecological analysis of aggregated cases was used to report trends over time. Additionally, we used multivariable log binomial regression to identify patient characteristics associated with microbiologically confirmed PTB, EPTB, and TB-HIV co-infection.

Results

Microbiologically confirmed PTB proportion increased over time. Young age was identified as an important risk factor for EPTB (adjusted prevalence ratio [aPR] = 1.74, 95% CI 0.97, 3.13) while HIV coinfection was negatively associated with EPTB (aPR = 0.73, 95% CI 0.55, 0.97). While previous TB history was associated with a lower likelihood of EPTB (aPR = 0.42, 95% CI 0.25, 0.70), it was associated with an increased risk of TB-HIV coinfection (aPR = 1.37, 95% CI 1.10, 1.71). Clinically diagnosed PTB patients were more likely to have TB-HIV coinfection compared to microbiologically confirmed PTB patients (aPR = 1.32, 95% CI 1.02, 1.72).

Conclusions

Increasing proportion of microbiologically confirmed PTB may suggest delayed access to treatment, severe disease and increased risk of intramural transmission. Associations with clinical/demographic factors varied for different types of TB and were not always consistent with what has been previously reported for the general population, necessitating the need to refocus prison TB control/treatment strategies based on context specific epidemiological factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01699-w.

The effect of empirical and laboratory-confirmed tuberculosis on treatment outcomes

The World Health Organization (WHO) criteria for diagnosing and treating Tuberculosis (TB) includes clinical signs, therefore not requiring bacteriological laboratory confirmation. In resource-limited settings, including Kenya, this empirical TB treatment is routine practice however limited data exist on patient clinical outcomes when comparing the method of diagnosis. We evaluated TB treatment outcomes comparing clinically diagnosed and bacteriologically confirmed TB, 6 months after starting treatment of TB in a rural county in Kenya. Our analysis compared patients with a clinical versus a bacteriologically confirmed TB diagnosis. In this retrospective analysis, we included all adults (≥ 18 years) starting treatment of TB and followed up for 6 months, within the County TB surveillance database from 2012 to 2018. Patients included from both public and private facilities. The TB treatment outcomes assessed included treatment success, treatment failure, death, defaulted and transferred out. We used survival regression models to assess effect of type of diagnosis on TB treatment outcome defining time at risk from date of starting treatment to experiencing one of the treatment outcomes or completing 6-months of treatment. A total of 12,856 patients; median age 37 [IQR 28 − 50] years were included. 7639 (59%) were male while 11,339 (88%) were pulmonary TB cases. Overall, 11,633 (90%) were given first-line TB treatment and 3791 (29%) were HIV infected. 6472 (50%) of the patients were clinically diagnosed of whom 4521/6472 (70%) had a negative sputum/GeneXpert test. During the study 5565 person-years (PYs) observed, treatment success was 82% and 83% amongst clinically and bacteriologically diagnosed patients (P = 0.05). There were no significant differences in defaulting (P = 0.70) or transfer out (P = 0.19) between clinically and bacteriologically diagnosed patients. Mortality was significantly higher among clinically diagnosed patients: 639 (9.9%) deaths compared to 285 (4.5%) amongst the bacteriologically diagnosed patients; aHR 5.16 (95%CI 2.17 − 12.3) P < 0.001. Our study suggests survival during empirical TB treatment is significantly lower compared to patients with laboratory evidence, irrespective of HIV status and age. To improve TB treatment outcomes amongst clinically diagnosed patients, we recommend systematic screening for comorbidities, prompt diagnosis and management of other infections.