A model of tuberculosis screening for pregnant women in resource-limited settings using Xpert MTB/RIF

Prevalence, acceptability, and cost of routine screening for pulmonary tuberculosis among pregnant women in Cotonou, Benin

OBJECTIVES

We sought to evaluate the yield, cost, feasibility, and acceptability of routine tuberculosis (TB) screening of pregnant women in Cotonou, Benin.

DESIGN

Mixed-methods, cross-sectional study with a cost assessment.

SETTING

Eight participating health facilities in Cotonou, Benin.

PARTICIPANTS

Consecutive pregnant women presenting for antenatal care at any participating site who were not in labor or currently being treated for TB from April 2017 to April 2018.

INTERVENTIONS

Screening for the presence of TB symptoms by midwives and Xpert MTB/RIF for those with cough for at least two weeks. Semi-structured interviews with 14 midwives and 16 pregnant women about experiences with TB screening.

PRIMARY AND SECONDARY OUTCOME MEASURES

Proportion of pregnant women with cough of at least two weeks and/or microbiologically confirmed TB. The cost per pregnant woman screened and per TB case diagnosed in 2019 USD from the health system perspective.

RESULTS

Out of 4,070 pregnant women enrolled in the study, 94 (2.3%) had a cough for at least two weeks at the time of screening. The average (standard deviation) age of symptomatic women was 26 ± 5 years and 5 (5.3%) had HIV. Among the 94 symptomatic women, 2 (2.3%) had microbiologically confirmed TB for a TB prevalence of 49 per 100,000 (95% CI: 6 to 177 per 100,000) among pregnant women enrolled in the study. The average cost to screen one pregnant woman for TB was $1.12 USD and the cost per TB case diagnosed was $2271 USD. Thematic analysis suggested knowledge of TB complications in pregnancy was low, but that routine TB screening was acceptable to both midwives and pregnant women.

CONCLUSION

Enhanced screening for TB among pregnant women is feasible, acceptable, and inexpensive per woman screened, however in this setting has suboptimal yield even if it can contribute to enhance TB case finding.

Achieving maternal viral load suppression for elimination of mother-to-child transmission of HIV in South Africa

OBJECTIVE

To describe changes in maternal viral control over time in South African women living with HIV (WLHIV) using surveillance data from the National Health Laboratory Service's Corporate Data Warehouse (NHLS CDW).

DESIGN

A retrospective cohort analysis of maternal viral load during pregnancy and up to 15 months postpartum was performed amongst WLHIV (15-49 years) within the public-health sector between 2016 and 2017.

METHODS

HIV and pregnancy-related test data were used to create a synthetic cohort of pregnant WLHIV from the NHLS CDW. Syphilis-screening, in association with ward type and/or postpregnancy cervical screening and/or birth HIV test and/or positive β-hCG, was used as a proxy for pregnancy. The syphilis-screening date marked the first antenatal care visit (fANC). Fractional polynomial models described viral load evolution from fANC up to 15 months postdelivery. Piecewise linear regression models determined factors associated with viral load decline.

FINDINGS

Among 178 319 pregnant WLHIV, 345 174 viral load tests were performed [median = 2 (IQR: 2-3) per woman]. At fANC, 85 545 (48%) women were antiretroviral therapy (ART) experienced; 88 877 (49.8%) were not and 3897 (2.2%) unknown. Proportions of viraemia (viral load ≥50 copies/ml) were 39 756 (53.6%) at first viral load performed during pregnancy, 14 780 (36.9%) at delivery and 24 328 (33.5%) postpartum. Maternal age at least 25 years, CD4+ cell count at least 500 cells/μl and viral load less than 50 copies/ml at baseline predicted sustained viral load suppression during follow-up.

CONCLUSION

Despite high-ART coverage among pregnant women in South Africa, only 63% of WLHIV achieved viral load less than 50 copies/ml at delivery. Maternal viral load monitoring requires prioritization for maternal health and eMTCT.

Tuberculosis-HIV Co-Infection: Progress and Challenges After Two Decades of Global Antiretroviral Treatment Roll-Out

Despite wide antiretroviral scale-up during the past two decades resulting in declining new infections and mortality globally, HIV-associated tuberculosis remains as a major public health concern. Tuberculosis is the leading HIV-associated opportunistic infection and the main cause of death globally and, particularly, in resource-limited settings. Several challenges exist regarding diagnosis, global implementation of latent tuberculosis treatment, management of active tuberculosis, delivery of optimal patient-centered TB and HIV prevention and care in high burden countries. In this article we review the advances on pathogenesis, diagnosis, and treatment after nearly two decades of global roll-out of antiretroviral therapy and discuss the current challenges for the global control of tuberculosis-HIV co-infection.

Burden of tuberculosis and challenges related to screening and diagnosis in Ethiopia

INTRODUCTION

One-third of tuberculosis (TB) cases in Ethiopia are missing from care for reasons that are not well studied. The aim of this study was to assess TB burden and identify challenges related to TB screening and diagnosis in Ethiopia.

METHODS

A facility-based cross-sectional study was conducted in seven health facilities selected from two regions and 2 city administrations of Ethiopia using stratified random sampling procedures. The data of 1,059,065 patients were included from outpatient department, HIV clinic, diabetic, and maternal-child health clinics. Data were collected from October to December 2018 using a retrospective review of three years' facility data (2015 to 2017) supplemented by a semi-structured interview with purposively selected health care workers and heads of the health facilities.

RESULTS

A total of 1,059,065 patients visited the health facilities in three years, of these, 978,480 (92.4%) were outpatients. Of the total, 20,284 (2%) were presumptive TB cases (with 14 days or more cough), 12.2% (2483/20,284) of which had TB. For the type of TB, 604 (24.3%) were smear-positive pulmonary TB (PTB), 789 (31.8%) were smear-negative PTB, 719 (29%) were extra-pulmonary TB, and data were missing for the rest. TB screening was integrated into HIV clinic, outpatient department, diabetic clinic but not with the maternal and child clinics. High patient load, weak TB laboratory specimen referral system, and shortage of TB diagnostic tools including Xpert MTB/RIF assay and chest X-ray, were the major challenges in the screening and diagnosis of TB.

CONCLUSION

The burden of TB was high in the study setting, and frequent interruption of laboratory reagents and supplies hampered TB screening and diagnostic services. Realizing the END-TB strategy in such resource-limited settings requires sustainable TB diagnostic capacity and improved case detection mechanisms, with national TB programs strongly integrated into the general health care system.

Tuberculosis-HIV Co-Infection: Progress and Challenges After Two Decades of Global Antiretroviral Treatment Roll-Out

Despite wide antiretroviral scale-up during the past two decades resulting in declining new infections and mortality globally, HIV-associated tuberculosis remains as a major public health concern. Tuberculosis is the leading HIV-associated opportunistic infection and the main cause of death globally and, particularly, in resource-limited settings. Several challenges exist regarding diagnosis, global implementation of latent tuberculosis treatment, management of active tuberculosis, delivery of optimal patient-centered TB and HIV prevention and care in high burden countries. In this article we review the advances on pathogenesis, diagnosis, and treatment after nearly two decades of global roll-out of antiretroviral therapy and discuss the current challenges for the global control of tuberculosis-HIV co-infection.

A Clinical TB Detection Method Based on Molecular Typing Technique with Quality Control

The gold standard for diagnosing pulmonary Mycobacterium tuberculosis (TB) is the detection of tubercle bacillus in patient sputum samples. However, current methods either require long waiting times to culture the bacteria or have a risk of getting false-positive results due to cross-contamination. In this study, a method to detect tubercle bacillus based on the molecular typing technique is presented. This method can detect genetic units, variable number of tandem repeat (VNTR), which are the characteristic of tuberculosis (TB), and performs quality control using a mathematical model, ensuring the reliability of the results. Compared to other methods, the proposed method was able to process and diagnose a large volume of samples in a run time of six hours, with high sensitivity and specificity. Our method is also in the pipeline for implementation in clinical testing. Reliable and confirmed results are stored into a database, and these data are used to further refine the model. As the volume of data processed from reliable samples increases, the diagnostic power of the model improves. In addition to improving the quality control scheme, the collected data can be also used to support other TB research, such as that regarding the evolution of the tubercle bacillus.

Maternal and perinatal mortality and morbidity associated with tuberculosis during pregnancy and the postpartum period: a systematic review and meta-analysis

BACKGROUND

There is a dearth of data on the clinical features and outcomes of active tuberculosis (TB) in pregnancy. Studies have shown varied results and the relationship between TB and adverse pregnancy outcomes remains unclear.

OBJECTIVES

We conducted a systematic review and meta-analysis to evaluate pregnancy outcomes associated with TB.

SEARCH STRATEGY

Major databases were searched from inception until December 2015 without restrictions using the terms: 'TB', 'pregnancy', 'maternal morbidity', 'mortality' and 'perinatal morbidity', 'mortality'.

SELECTION CRITERIA

We included studies that compared the outcomes of pregnant women with and without active TB.

DATA COLLECTION AND ANALYSIS

We computed odds ratios for maternal and perinatal complications, and pooled them using a random effects model. We assessed for heterogeneity using chi-squared tests and evaluated its magnitude using the I2 statistic. We used the Newcastle-Ottawa scale for quality assessment.

MAIN RESULTS

Thirteen studies, including 3384 pregnancies with active TB and 119 448 without TB were included. Compared with pregnant women without TB, pregnant women with active TB was associated with increased odds of maternal morbidity [odds ratio (OR) 2.8, 95% CI 1.7-4.6; I2  = 60.3%], anaemia (OR 3.9, 95% CI 2.2-6.7; I2  = 29.8%), caesarean delivery (OR 2.1, 95% CI 1.2-3.8; I2  = 61.1%), preterm birth (OR 1.7, 95% CI 1.2-2.4; I2  = 66.5%), low birth weight (OR 1.7, 95% CI 1.2-2.4; I2  = 53.7%), birth asphyxia (OR 4.6, 95% CI 2.4-8.6; I2  = 46.3), and perinatal death (OR 4.2, 95% CI 1.5-11.8; I2  = 57.2%).

AUTHOR'S CONCLUSION

Active TB in pregnancy is associated with adverse maternal and fetal outcomes. Early diagnosis of TB is important to prevent significant maternal and perinatal complications.

TWEETABLE ABSTRACT

Active tuberculosis in pregnancy is associated with adverse maternal and perinatal outcomes.

Performance of Clinical Screening Algorithms for Tuberculosis Intensified Case Finding among People Living with HIV in Western Kenya

OBJECTIVE

To assess the performance of symptom-based screening for tuberculosis (TB), alone and with chest radiography among people living with HIV (PLHIV), including pregnant women, in Western Kenya.

DESIGN

Prospective cohort study.

METHODS

PLHIV from 15 randomly-selected HIV clinics were screened with three clinical algorithms [World Health Organization (WHO), Ministry of Health (MOH), and "Improving Diagnosis of TB in HIV-infected persons" (ID-TB/HIV) study], underwent chest radiography (unless pregnant), and provided two or more sputum specimens for smear microscopy, liquid culture, and Xpert MTB/RIF. Performance of clinical screening was compared to laboratory results, controlling for the complex design of the survey.

RESULTS

Overall, 738 (85.6%) of 862 PLHIV enrolled were included in the analysis. Estimated TB prevalence was 11.2% (95% CI, 9.9-12.7). Sensitivity of the three screening algorithms was similar [WHO, 74.1% (95% CI, 64.1-82.2); MOH, 77.5% (95% CI, 68.6-84.5); and ID-TB/HIV, 72.5% (95% CI, 60.9-81.7)]. Sensitivity of the WHO algorithm was significantly lower among HIV-infected pregnant women [28.2% (95% CI, 14.9-46.7)] compared to non-pregnant women [78.3% (95% CI, 67.3-86.4)] and men [77.2% (95% CI, 68.3-84.2)]. Chest radiography increased WHO algorithm sensitivity and negative predictive value to 90.9% (95% CI, 86.4-93.9) and 96.1% (95% CI, 94.4-97.3), respectively, among asymptomatic men and non-pregnant women.

CONCLUSIONS

Clinical screening missed approximately 25% of laboratory-confirmed TB cases among all PLHIV and more than 70% among HIV-infected pregnant women. National HIV programs should evaluate the feasibility of laboratory-based screening for TB, such as a single Xpert MTB/RIF test for all PLHIV, especially pregnant women, at enrollment in HIV services.

Tuberculosis Case Finding in HIV-Infected Pregnant Women in Kenya Reveals Poor Performance of Symptom Screening and Rapid Diagnostic Tests

BACKGROUND

Tuberculosis (TB) during pregnancy in HIV-infected women is associated with poor maternal and infant outcomes. There are limited data on TB prevalence, optimal TB screening, and performance of rapid diagnostics in pregnant HIV-infected women.

METHODS

We conducted a cross-sectional study among HIV-infected pregnant women seeking antenatal care in western Kenya. After a standardized questionnaire, sputum smear microscopy for acid-fast bacilli, mycobacterial liquid culture, GeneXpert MTB/RIF (Xpert), urine lipoarabinomannan, and tuberculin skin testing were performed. We determined prevalence and correlates of culture-confirmed pulmonary TB, and compared diagnostic performance of World Health Organization (WHO) symptom screening and rapid diagnostic tests to sputum culture.

RESULTS

Between July 2013 and July 2014, we enrolled 306 women. Among 288 women with a valid sputum culture result, 54% were on antiretroviral treatment, median CD4 cell count was 437 cell per cubic millimeter (IQR 342-565), and prevalence of culture-confirmed pulmonary TB was 2.4% (confidence interval: 1.0% to 4.9%). Cough >2 weeks (P = 0.04) and positive tuberculin skin testing (≥ 5 mm, P = 0.03) were associated with pulmonary TB. Women with TB were 23-fold (95% confidence interval: 4.4 to 116.6) more likely to report a household member with TB symptoms (P = 0.002). WHO symptom screen (43%), acid-fast bacilli smear (0%), Xpert (43%), and lipoarabinomannan (0%) had low sensitivity but high specificity (81%, 99%, 99%, and 95%, respectively) for pulmonary TB.

CONCLUSIONS

HIV-infected pregnant women had appreciable prevalence of pulmonary TB despite modest immunosuppression. Current TB screening and diagnostic tools perform poorly in pregnant HIV-infected women. Adapted TB screening tools that include household member TB symptoms may be useful in this population.

Perspectives on tuberculosis in pregnancy

Tuberculosis (TB) has been recognized as an important cause of morbidity and mortality in pregnancy for nearly a century, but research and efforts to roll out comprehensive TB screening and treatment in high-risk populations such as those with a high prevalence of HIV or other diseases of poverty, have lagged behind similar efforts to address HIV infection in pregnancy and the prevention of mother-to-child-transmission. Immunological changes during pregnancy make the activation of latent TB infection or de novo infection more likely than among non-pregnant women. TB treatment in pregnancy poses several problems that have been under-researched, such as contraindications to anti-TB and anti-HIV drugs and potential risks to the neonate, which are particularly important with respect to second-line TB treatment. Whilst congenital TB is thought to be rare, data from high HIV burden settings suggest this is not the case. There is a need for more studies screening for TB in neonates and observing outcomes, and testing preventative or curative actions. National tuberculosis control programmes (NTPs) should work with antenatal and national HIV programmes in high-burden populations to provide screening at antenatal clinics, or to establish functioning systems whereby pregnant women at high risk can drop in to routine NTP screening stations.

Tuberculosis in pregnancy: an estimate of the global burden of disease

BACKGROUND

The estimated number of maternal deaths in 2013 worldwide was 289 000, a 45% reduction from 1990. Non-obstetric causes such as infectious diseases including tuberculosis now account for 28% of maternal deaths. In 2013, 3·3 million cases of tuberculosis were estimated to occur in women globally. During pregnancy, tuberculosis is associated with poor outcomes, including increased mortality in both the neonate and the pregnant woman. The aim of our study was to estimate the burden of tuberculosis disease among pregnant women, and to describe how maternal care services could be used as a platform to improve case detection.

METHODS

We used publicly accessible country-level estimates of the total population, distribution of the total population by age and sex, crude birth rate, estimated prevalence of active tuberculosis, and case notification data by age and sex to estimate the number of pregnant women with active tuberculosis for 217 countries. We then used indicators of health system access and tuberculosis diagnostic test performance obtained from published literature to determine how many of these cases could ultimately be detected.

FINDINGS

We estimated that 216 500 (95% uncertainty range 192 100-247 000) active tuberculosis cases existed in pregnant women globally in 2011. The greatest burdens were in the WHO African region with 89 400 cases and the WHO South East Asian region with 67 500 cases in pregnant women. Chest radiography or Xpert RIF/MTB, delivered through maternal care services, were estimated to detect as many as 114 100 and 120 300 tuberculosis cases, respectively.

Screening for tuberculosis in pregnancy: do we need more than a symptom screen? Experience from western Kenya

OBJECTIVES

1) To explore the utility of tuberculosis (TB) symptom screening for symptoms of ≥2 weeks' duration in a routine setting, and 2) to compare differences in TB diagnosis between human immunodeficiency virus (HIV) infected and non-HIV-infected pregnant women in western Kenya.

DESIGN

Comparative cross-sectional study among pregnant women with known HIV status screened for TB from 2010 to 2012, in Eldoret, western Kenya.

RESULTS

Of 2983 participants, respectively 34 (1%), 1488 (50.5%) and 1461 (49.5%) had unknown, positive and negative HIV status. The median age was respectively 30 years (interquartile range [IQR] 26-35) and 26 years (IQR 24-31) in HIV-infected and non-infected participants. A positive symptom screen was found in respectively 8% (119/1488) and 5% (67/1461) of the HIV-infected and non-infected women. The median CD4 count at enrolment was 377 cells/μl (IQR 244-530) for HIV-infected women. One non-HIV-infected patient was sputum-positive. For HIV-infected women, TB was presumptively treated in 1% (16/1488) based on clinical symptoms and chest X-ray. Cumulatively, anti-tuberculosis treatment was offered to 0.6% (17/2949) of the participants.

CONCLUSION

This study does not seem to demonstrate the utility of TB symptom screening questionnaires in a routine setting among pregnant women, either HIV-infected or non-infected, in western Kenya.

Role of GeneXpert MTB/Rif Assay in Diagnosing Tuberculosis in Pregnancy and Puerperium

Presentation of tuberculosis (TB) in pregnancy may be atypical with diagnostic challenges. Two patients with complicated pregnancy outcomes, foetal loss and live premature delivery at 5 and 7 months of gestation, respectively, and maternal loss, were diagnosed with pulmonary TB. Chest radiography and computed tomography showed widespread reticuloalveolar infiltrates and consolidation with cavitations, respectively. Both patients were Human Immunodeficiency Virus (HIV) seronegative and sputum smear negative for TB. Sputum GeneXpert MTB/Rif (Xpert MTB/RIF) was positive for Mycobacterium tuberculosis. To strengthen maternal and childhood TB control, screening with same-day point-of-care Xpert MTB/RIF is advocated among both HIV positive pregnant women and symptomatic HIV negative pregnant women during antenatal care in pregnancy and at puerperium.

Tuberculosis care for pregnant women: a systematic review

Background

Tuberculosis (TB) during pregnancy may lead to severe consequences affecting both mother and child. Prenatal care could be a very good opportunity for TB care, especially for women who have limited access to health services. The aim of this review was to gather and evaluate studies on TB care for pregnant women.

Methods

We used a combination of the terms “tuberculosis” and “pregnancy”, limited to human, to search for published articles. Studies reflecting original data and focusing on TB care for pregnant women were included. All references retrieved were collected using the Reference Manager software (Version 11).

Results

Thirty five studies were selected for review and their data showed that diagnosis was often delayed because TB symptoms during pregnancy were not typical. TB prophylaxis and anti-TB therapy appeared to be safe and effective for pregnant women and their babies when suitable follow up and early initiation were present, but the compliance rate to TB prophylaxis is still low due to lack of follow up and referral services. TB care practices in the reviewed studies were in line in principle with the WHO International Standards for Tuberculosis Care (ISTC).

Conclusions

Integration of TB care within prenatal care would improve TB diagnosis and treatment for pregnant women. To improve the quality of TB care, it is necessary to develop national level guidelines based on the ISTC with detailed guidelines for pregnant women.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0617-x) contains supplementary material, which is available to authorized users.

Advances in tuberculosis diagnostics: the Xpert MTB/RIF assay and future prospects for a point-of-care test

Rapid progress has been made in the development of new diagnostic assays for tuberculosis in recent years. New technologies have been developed and assessed, and are now being implemented. The Xpert MTB/RIF assay, which enables simultaneous detection of Mycobacterium tuberculosis (MTB) and rifampicin (RIF) resistance, was endorsed by WHO in December, 2010. This assay was specifically recommended for use as the initial diagnostic test for suspected drug-resistant or HIV-associated pulmonary tuberculosis. By June, 2012, two-thirds of countries with a high tuberculosis burden and half of countries with a high multidrug-resistant tuberculosis burden had incorporated the assay into their national tuberculosis programme guidelines. Although the development of the Xpert MTB/RIF assay is undoubtedly a landmark event, clinical and programmatic effects and cost-effectiveness remain to be defined. We review the rapidly growing body of scientific literature and discuss the advantages and challenges of using the Xpert MTB/RIF assay in areas where tuberculosis is endemic. We also review other prospects within the developmental pipeline. A rapid, accurate point-of-care diagnostic test that is affordable and can be readily implemented is urgently needed. Investment in the tuberculosis diagnostics pipeline should remain a major priority for funders and researchers.