Towards host-directed therapies for tuberculosis

The treatment of tuberculosis is based on combinations of drugs that directly target Mycobacterium tuberculosis. A new global initiative is now focusing on a complementary approach of developing adjunct host-directed therapies.

Psychological distress and its relationship with non-adherence to TB treatment: a multicentre study

BACKGROUND

The successful cure of tuberculosis (TB) is dependent on adherence to treatment. Various factors influence adherence, however, few are easily modifiable. There are limited data regarding correlates of psychological distress and their association with non-adherence to anti-TB treatment.

METHODS

In a trial of a new TB test, we measured psychological distress (K-10 score), TB-related health literacy, and morbidity (TBscore), prior to diagnosis in 1502 patients with symptoms of pulmonary TB recruited from clinics in Cape Town (n = 419), Harare (n = 400), Lusaka (n = 400), Durban (n = 200), and Mbeya (n = 83). Socioeconomic, demographic, and alcohol usage-related data were captured. Patients initiated on treatment had their DOTS cards reviewed at two-and six-months.

RESULTS

22 %(95 % CI: 20 %, 25 %) of patients had severe psychological distress (K-10 ≥ 30). In a multivariable linear regression model, increased K-10 score was independently associated with previous TB [estimate (95 % CI) 0.98(0.09-1.87); p = 0.0304], increased TBscore [1(0.80, 1.20); p <0.0001], and heavy alcohol use [3.08(1.26, 4.91); p = 0.0010], whereas male gender was protective [-1.47(-2.28, -0.62); p = 0.0007]. 26 % (95 % CI: 21 %, 32 %) of 261 patients with culture-confirmed TB were non-adherent. In a multivariable logistic regression model for non-adherence, reduced TBscore [OR (95 % CI) 0.639 (0.497, 0.797); p = 0.0001], health literacy score [0.798(0.696, 0.906); p = 0.0008], and increased K-10 [1.082(1.033, 1.137); p = 0.0012], and heavy alcohol usage [14.83(2.083, 122.9); p = 0.0002], were independently associated. Culture-positive patients with a K-10 score ≥ 30 were more-likely to be non-adherent (OR = 2.290(1.033-5.126); p = 0.0416].

CONCLUSION

Severe psychological distress is frequent amongst TB patients in Southern Africa. Targeted interventions to alleviate psychological distress, alcohol use, and improve health literacy in newly-diagnosed TB patients could reduce non-adherence to treatment.

Cryptococcal meningitis screening and community-based early adherence support in people with advanced HIV infection starting antiretroviral therapy in Tanzania and Zambia: an open-label, randomised controlled trial

BACKGROUND

Mortality in people in Africa with HIV infection starting antiretroviral therapy (ART) is high, particularly in those with advanced disease. We assessed the effect of a short period of community support to supplement clinic-based services combined with serum cryptococcal antigen screening.

METHODS

We did an open-label, randomised controlled trial in six urban clinics in Dar es Salaam, Tanzania, and Lusaka, Zambia. From February, 2012, we enrolled eligible individuals with HIV infection (age ≥18 years, CD4 count of <200 cells per μL, ART naive) and randomly assigned them to either the standard clinic-based care supplemented with community support or standard clinic-based care alone, stratified by country and clinic, in permuted block sizes of ten. Clinic plus community support consisted of screening for serum cryptococcal antigen combined with antifungal therapy for patients testing antigen positive, weekly home visits for the first 4 weeks on ART by lay workers to provide support, and in Tanzania alone, re-screening for tuberculosis at 6-8 weeks after ART initiation. The primary endpoint was all-cause mortality at 12 months, analysed by intention to treat. This trial is registered with the International Standard Randomised Controlled Trial Number registry, number ISCRTN 20410413.

FINDINGS

Between Feb 9, 2012, and Sept 30, 2013, 1001 patients were randomly assigned to clinic plus community support and 998 to standard care. 89 (9%) of 1001 participants in the clinic plus community support group did not receive their assigned intervention, and 11 (1%) of 998 participants in the standard care group received a home visit or a cryptococcal antigen screen rather than only standard care. At 12 months, 25 (2%) of 1001 participants in the clinic plus community support group and 24 (2%) of 998 participants in the standard care group had been lost to follow-up, and were censored at their last visit for the primary analysis. At 12 months, 134 (13%) of 1001 participants in the clinic plus community support group had died compared with 180 (18%) of 998 in the standard care group. Mortality was 28% (95% CI 10-43) lower in the clinic plus community support group than in standard care group (p=0·004).

INTERPRETATION

Screening and pre-emptive treatment for cryptococcal infection combined with a short initial period of adherence support after initiation of ART could substantially reduce mortality in HIV programmes in Africa.

FUNDING

European and Developing Countries Clinical Trials Partnership.

Burden of tuberculosis at post mortem in inpatients at a tertiary referral centre in sub-Saharan Africa: a prospective descriptive autopsy study

BACKGROUND

Patients with subclinical tuberculosis, smear-negative tuberculosis, extrapulmonary tuberculosis, multidrug-resistant tuberculosis, and asymptomatic tuberculosis are difficult to diagnose and may be missed at all points of health care. We did an autopsy study to ascertain the burden of tuberculosis at post mortem in medical inpatients at a tertiary care hospital in Lusaka, Zambia.

METHODS

Between April 5, 2012, and May 22, 2013, we did whole-body autopsies on inpatients aged at least 16 years who died in the adult inpatient wards at University Teaching Hospital, Lusaka, Zambia. We did gross pathological and histopathological analysis and processed lung tissues from patients with tuberculosis through the GeneXpert MTB/RIF assay to identify patients with multidrug-resistant tuberculosis. The primary outcome measure was specific disease or diseases stratified by HIV status. Secondary outcomes were missed tuberculosis, multidrug-resistant tuberculosis, and comorbidities with tuberculosis. Data were analysed using Pearson χ(2), the Mann-Whitney U test, and binary logistic regression.

FINDINGS

The median age of the 125 included patients was 35 years (IQR 29-43), 80 (64%) were men, and 101 (81%) were HIV positive. 78 (62%) patients had tuberculosis, of whom 66 (85%) were infected with HIV. 35 (45%) of these 78 patients had extrapulmonary tuberculosis. The risk of extrapulmonary tuberculosis was higher among HIV-infected patients than among uninfected patients (adjusted odds ratio 5·14, 95% CI 1·04-24·5; p=0·045). 20 (26%) of 78 patients with tuberculosis were not diagnosed during their life and 13 (17%) had undiagnosed multidrug-resistant tuberculosis. Common comorbidities with tuberculosis were pyogenic pneumonia in 26 patients (33%) and anaemia in 15 (19%).

INTERPRETATION

Increased clinical awareness and more proactive screening for tuberculosis and multidrug-resistant tuberculosis in inpatient settings is needed. Further autopsy studies are needed to ascertain the generalisability of the findings.

FUNDING

UBS Optimus Foundation, EuropeAID, and European Developing Countries Clinical Trials Partnership (EDCTP).

Risk assessment for yellow Fever in Western and north-Western provinces of zambia

Background:

North-Western and Western provinces of Zambia were reclassified as low-risk areas for yellow fever (YF). However, the current potential for YF transmission in these areas is unclear.

Aims:

To determine the current potential risk of YF infection.

Setting and Design:

A cross sectional study was conducted in North-Western and Western provinces of Zambia.

Materials and Methods:

Samples were tested for both YF virus-specific IgG and IgM antibodies by the ELISA and YF virus confirmation was done using Plaque Reduction Neutralization Test. The samples were also tested for IgG and IgM antibodies against other flaviviruses.

Results:

Out of the 3625 respondents who participated in the survey, 46.7% were males and 9.4% were aged less than 5 years. Overall, 58.1% of the participants slept under an impregnated insecticide-treated net and 20.6% reported indoor residual spraying of insecticides. A total of 616 (17.0%) samples were presumptive YF positive. The prevalence for YF was 0.3% for long-term infection and 0.2% for recent YF infection. None of the YF confirmed cases had received YF vaccine. Prevalence rates for other flaviviruses were 149 (4.1%) for Dengue, 370 (10.2%) for West Nile and 217 (6.0%) for Zika.

Conclusion:

There is evidence of past and recent infection of YF in both provinces. Hence, they are at a low risk for YF infection. Yellow fever vaccination should be included in the EPI program in the two provinces and strengthen surveillance with laboratory confirmation.

Emerging novel and antimicrobial-resistant respiratory tract infections: new drug development and therapeutic options

The emergence and spread of antimicrobial-resistant bacterial, viral, and fungal pathogens for which diminishing treatment options are available is of major global concern. New viral respiratory tract infections with epidemic potential, such as severe acute respiratory syndrome, swine-origin influenza A H1N1, and Middle East respiratory syndrome coronavirus infection, require development of new antiviral agents. The substantial rise in the global numbers of patients with respiratory tract infections caused by pan-antibiotic-resistant Gram-positive and Gram-negative bacteria, multidrug-resistant Mycobacterium tuberculosis, and multiazole-resistant fungi has focused attention on investments into development of new drugs and treatment regimens. Successful treatment outcomes for patients with respiratory tract infections across all health-care settings will necessitate rapid, precise diagnosis and more effective and pathogen-specific therapies. This Series paper describes the development and use of new antimicrobial agents and immune-based and host-directed therapies for a range of conventional and emerging viral, bacterial, and fungal causes of respiratory tract infections.

Rapid point of care diagnostic tests for viral and bacterial respiratory tract infections--needs, advances, and future prospects

Respiratory tract infections rank second as causes of adult and paediatric morbidity and mortality worldwide. Respiratory tract infections are caused by many different bacteria (including mycobacteria) and viruses, and rapid detection of pathogens in individual cases is crucial in achieving the best clinical management, public health surveillance, and control outcomes. Further challenges in improving management outcomes for respiratory tract infections exist: rapid identification of drug resistant pathogens; more widespread surveillance of infections, locally and internationally; and global responses to infections with pandemic potential. Developments in genome amplification have led to the discovery of several new respiratory pathogens, and sensitive PCR methods for the diagnostic work-up of these are available. Advances in technology have allowed for development of single and multiplexed PCR techniques that provide rapid detection of respiratory viruses in clinical specimens. Microarray-based multiplexing and nucleic-acid-based deep-sequencing methods allow simultaneous detection of pathogen nucleic acid and multiple antibiotic resistance, providing further hope in revolutionising rapid point of care respiratory tract infection diagnostics.

First sero-prevalence of dengue fever specific immunoglobulin G antibodies in Western and North-Western provinces of Zambia: a population based cross sectional study

BACKGROUND

Dengue fever is a tropical infectious disease caused by dengue virus (DENV), a single positive-stranded RNA Flavivirus. There is no published evidence of dengue in Zambia. The objective of the study was to determine the sero-prevalence and correlates for dengue fever specific IgG antibodies in Western and North-Western provinces in Zambia.

METHODS

A randomized cluster design was used to sample participants for yellow fever risk assessment. In order to rule out cross reactivity with other flaviviruses including dengue, differential antibody tests were done by ELISA. Data was processed using Epi Data version 3.1 and transferred to SPSS version 16.0 for analysis. Bivariate and multivariate analyses were performed to determine the association of dengue fever with various factors. Unadjusted odds ratios (OR), adjusted odds ratios (AOR) and their 95% confidence intervals (CI) are reported.

RESULTS

A total of 3,624 persons were sampled for dengue virus infection of whom 53.3% were female and 23.9% were in the 5-14 years age group. Most persons in the survey attained at least primary education (47.6%). No significant association was observed between sex and dengue virus infection (p = 1.000). Overall, 4.1% of the participants tested positive for Dengue IgG. In multivariate analysis, the association of age with Dengue infection showed that those below 5 years of age were 63% (AOR = 0.37; 95% CI [0.16, 0.86]) less likely to be infected with Dengue virus compared to those aged 45 years or older. A significant association was observed between grass thatched roofing and Dengue infection (AOR = 2.28; 95% CI [1.15, 4.53]) Respondents who used Insecticide Treated Nets (ITN) were 21% (AOR = 1.21; 95% CI [1.01, 1.44]) more likely to be infected with dengue infection than those who did not use ITNs. Meanwhile, participants who visited Angola were 73% (AOR = 1.73; 95% CI [1.27, 2.35]) more likely to be infected with Dengue virus than those who did not visit Angola.

CONCLUSION

This study provides the first evidence of dengue infection circulation in both North-Western and Western provinces of Zambia. It is important that surveillance activities for Dengue and diagnostic systems are expanded and strengthened, nationwide in order to capture information related to dengue virus and other flaviviruses.

Trends in all-cause mortality during the scale-up of an antiretroviral therapy programme: a cross-sectional study in Lusaka, Zambia

OBJECTIVE

To follow the trends in all-cause mortality in Lusaka, Zambia, during the scale-up of a national programme of antiretroviral therapy (ART).

METHODS

Between November 2004 and September 2011, we conducted 12 survey rounds as part of a cross-sectional study in Lusaka, with independent sampling in each round. In each survey, we asked the heads of 3600 households to state the number of deaths in their households in the previous 12 months and the number of orphans aged less than 16 years in their households and investigated the heads' knowledge, attitudes and practices related to human immunodeficiency virus (HIV).

FINDINGS

The number of deaths we recorded - per 100 person-years - in each survey ranged from 0.92 (95% confidence interval, CI: 0.78-1.09) in September 2011, to 1.94 (95% CI: 1.60-2.35) in March 2007. We found that mortality decreased only modestly each year (mortality rate ratio: 0.98; 95% CI: 0.95-1.00; P = 0.093). The proportion of households with orphans under the age of 16 years decreased from 17% in 2004 to 7% in 2011. The proportions of respondents who had ever been tested for HIV, had a comprehensive knowledge of HIV, knew where to obtain free ART and reported that a non-pregnant household member was receiving ART gradually increased.

CONCLUSION

The expansion of ART services in Lusaka was not associated with a reduction in all-cause mortality. Coverage, patient adherence and retention may all have to be increased if ART is to have a robust and lasting impact at population level in Lusaka.

Frequency of APOE, MTHFR and ACE polymorphisms in the Zambian population

Background

Polymorphisms within the apolipoprotein-E (APOE), Methylenetetrahydrofolate reductase (MTHFR) and Angiotensin I-converting enzyme (ACE) genes has been associated with cardiovascular and cerebrovascular disorders, Alzheimer’s disease and other complex diseases in various populations. The aim of the study was to analyze the allelic and genotypic frequencies of APOE, MTHFR C677T and ACE I/D gene polymorphisms in the Zambian population.

Results

The allele frequencies of APOE polymorphism in the Zambian populations were 13.8%, 59.5% and 26.7% for the ε2, ε3 and ε4 alleles respectively. MTHFR C677T and ACE I/D allele frequencies were 8.6% and 13.8% for the T and D minor alleles respectively. The ε2ε2 genotype and TT genotype were absent in the Zambian population. The genetic distances between Zambian and other African and non-African major populations revealed an independent variability of these polymorphisms.

Conclusion

We found that the APOE ε3 allele and the I allele of the ACE were significantly high in our study population while there were low frequencies observed for the MTHFR 677 T and ACE D alleles. Our analysis of the APOE, MTHFR and ACE polymorphisms may provide valuable insight into the understanding of the disease risk in the Zambian population.

Feasibility, accuracy, and clinical effect of point-of-care Xpert MTB/RIF testing for tuberculosis in primary-care settings in Africa: a multicentre, randomised, controlled trial

BACKGROUND

The Xpert MTB/RIF test for tuberculosis is being rolled out in many countries, but evidence is lacking regarding its implementation outside laboratories, ability to inform same-day treatment decisions at the point of care, and clinical effect on tuberculosis-related morbidity. We aimed to assess the feasibility, accuracy, and clinical effect of point-of-care Xpert MTB/RIF testing at primary-care health-care facilities in southern Africa.

METHODS

In this pragmatic, randomised, parallel-group, multicentre trial, we recruited adults with symptoms suggestive of active tuberculosis from five primary-care health-care facilities in South Africa, Zimbabwe, Zambia, and Tanzania. Eligible patients were randomly assigned using pregenerated tables to nurse-performed Xpert MTB/RIF at the clinic or sputum smear microscopy. Participants with a negative test result were empirically managed according to local WHO-compliant guidelines. Our primary outcome was tuberculosis-related morbidity (measured with the TBscore and Karnofsky performance score [KPS]) in culture-positive patients who had begun anti-tuberculosis treatment, measured at 2 months and 6 months after randomisation, analysed by intention to treat. This trial is registered with Clinicaltrials.gov, number NCT01554384.

FINDINGS

Between April 12, 2011, and March 30, 2012, we randomly assigned 758 patients to smear microscopy (182 culture positive) and 744 to Xpert MTB/RIF (185 culture positive). Median TBscore in culture-positive patients did not differ between groups at 2 months (2 [IQR 0-3] in the smear microscopy group vs 2 [0·25-3] in the MTB/RIF group; p=0·85) or 6 months (1 [0-3] vs 1 [0-3]; p=0·35), nor did median KPS at 2 months (80 [70-90] vs 90 [80-90]; p=0·23) or 6 months (100 [90-100] vs 100 [90-100]; p=0·85). Point-of-care MTB/RIF had higher sensitivity than microscopy (154 [83%] of 185 vs 91 [50%] of 182; p=0·0001) but similar specificity (517 [95%] 544 vs 540 [96%] of 560; p=0·25), and had similar sensitivity to laboratory-based MTB/RIF (292 [83%] of 351; p=0·99) but higher specificity (952 [92%] of 1037; p=0·0173). 34 (5%) of 744 tests with point-of-care MTB/RIF and 82 (6%) of 1411 with laboratory-based MTB/RIF failed (p=0·22). Compared with the microscopy group, more patients in the MTB/RIF group had a same-day diagnosis (178 [24%] of 744 vs 99 [13%] of 758; p<0·0001) and same-day treatment initiation (168 [23%] of 744 vs 115 [15%] of 758; p=0·0002). Although, by end of the study, more culture-positive patients in the MTB/RIF group were on treatment due to reduced dropout (15 [8%] of 185 in the MTB/RIF group did not receive treatment vs 28 [15%] of 182 in the microscopy group; p=0·0302), the proportions of all patients on treatment in each group by day 56 were similar (320 [43%] of 744 in the MTB/RIF group vs 317 [42%] of 758 in the microscopy group; p=0·6408).

INTERPRETATION

Xpert MTB/RIF can be accurately administered by a nurse in primary-care clinics, resulting in more patients starting same-day treatment, more culture-positive patients starting therapy, and a shorter time to treatment. However, the benefits did not translate into lower tuberculosis-related morbidity, partly because of high levels of empirical-evidence-based treatment in smear-negative patients.

FUNDING

European and Developing Countries Clinical Trials Partnership, National Research Foundation, and Claude Leon Foundation.

High rates of congenital cytomegalovirus infection linked with maternal HIV infection among neonatal admissions at a large referral center in sub-Saharan Africa

BACKGROUND

 Congenital cytomegalovirus (CMV) infection is the major infectious cause of birth defects and hearing loss globally. There is a growing recognition of the potential clinical impact of congenital CMV infections in high-seroprevalence settings.

METHODS

 A cross-sectional study of neonatal admissions at a large referral center in sub-Saharan Africa to determine the prevalence of both symptomatic and asymptomatic congenital CMV infection was performed. Real-time polymerase chain reaction was used to screen DNA-extracted sera, urine, and saliva, and an enzyme-linked immunosorbent assay was used to screen serum samples for anti-CMV immunoglobulin M. Multivariate binary logistic regression was used to identify risk factors associated with increased odds of congenital CMV infection.

RESULTS

 Congenital CMV was detected in 3.8% (15/395) of neonates. Among these infants, 6 of 15 (40%) presented with jaundice, 1 of whom also had petechiae. Congenital CMV infection was detected in 9 of 79 (11.4%; 95% confidence interval [CI], 6.1%-20.3%) neonates born to human immunodeficiency virus (HIV)-infected mothers, and both maternal HIV (odds ratio [OR], 6.661 [95% CI, 2.126-20.876], P = .001) and jaundice (OR, 5.701 [95% CI, 1.776-18.306], P = .003) were independently linked with significantly increased odds of congenital CMV infection.

CONCLUSIONS

 Congenital and early infant CMV infections may have important consequences for child health in sub-Saharan Africa and other high HIV and CMV seroprevalence populations globally.

Use of the Xpert(®) MTB/RIF assay for diagnosing pulmonary tuberculosis comorbidity and multidrug-resistant TB in obstetrics and gynaecology inpatient wards at the University Teaching Hospital, Lusaka, Zambia

OBJECTIVES

In high-tuberculosis (TB)-endemic countries, comorbidity of pulmonary TB in hospitalised patients with non-communicable diseases is well documented. In this study, we evaluated the use of the Xpert® MTB/RIF assay for the detection of concomitant pulmonary TB in patients admitted to the University Teaching Hospital, Lusaka, Zambia, with a primary obstetric or gynaecological condition.

METHODS

The Study population were inpatients admitted with a primary obstetric or gynaecological problem who had a concomitant cough and were able to expectorate a sputum sample. Sputum samples from 94 patients were analysed for the presence of Mycobacterium tuberculosis (M.tb) by standard smear microscopy, MGIT culture, MGIT drug-susceptibility testing (DST) and the Xpert® MTB/RIF assay. The sensitivity and specificity of the Xpert® MTB/RIF assay were evaluated against the culture gold standard.

RESULTS

Twenty-six of 94 (27.7%) patients had culture-confirmed pulmonary TB. The Xpert® MTB/RIF assay had a sensitivity of 80.8% [95% CI: 60.0–92.7%]) compared against MGIT culture. The Xpert® MTB/RIF assay was more sensitive than sputum smear microscopy (21/26 (80.8%) vs. 13/26 (50.0%), P = 0.02) and detected an additional eight culture-confirmed cases. Culture DST analysis identified two monoresistant M.tb strains: one resistant to rifampicin (rifampicin sensitive by the Xpert® MTB/RIF assay) and one to ethambutol. HIV infection was linked with a 3-fold increase in risk of TB, accounting for 87.5% (21/24) of TB cases. 50% of cases presented as comorbidities with other communicable diseases (CDs) and non-communicable diseases (NCDs).

CONCLUSIONS

As an alternative to sputum microscopy, the Xpert® MTB/RIF assay provides a sensitive, specific and rapid method for the diagnosis of pulmonary TB in obstetric or gynaecological inpatients. Pulmonary TB is an important cause of concomitant comorbidity to the obstetric or gynaecological condition necessitating admission. TB and HIV comorbidities with other communicable and non-communicable diseases were also common. More proactive screening for TB comorbidity is required in obstetric and gynaecological wards.

Trends in childhood tuberculosis in Zambia: a situation analysis

OBJECTIVES

To ascertain childhood tuberculosis (TB) trends, human immunodeficiency virus (HIV) co-infection rates and multi-drug resistant TB (MDR-TB) prevalence rates in Zambia.

METHODS

A retrospective review of Zambian annual TB notification data and National TB Programme reports for a 7 year period (2004-2011). TB trends were stratified by age and HIV status.

RESULTS

The total number of children notified during this period with all forms of TB was 40 976. A total of 2670 of 40 976 (6%) were smear-positive cases. Notification rates of all forms of childhood TB show a decline in trends from 135 per 100 000 population in 2004, to 69 per 100 000 population in 2011.

CONCLUSIONS

Childhood TB is an important but neglected problem in Zambia highlighted by the fact that no data exists on HIV co-infection and MDR-TB. Strengthening of the National TB Programme and diagnostics services/algorithms are required to accurately define the TB burden, HIV co-infection and MDR-TB rates in children in Zambia.

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.

Tuberculosis comorbidity with communicable and non-communicable diseases: integrating health services and control efforts

Recent data for the global burden of disease reflect major demographic and lifestyle changes, leading to a rise in non-communicable diseases. Most countries with high levels of tuberculosis face a large comorbidity burden from both non-communicable and communicable diseases. Traditional disease-specific approaches typically fail to recognise common features and potential synergies in integration of care, management, and control of non-communicable and communicable diseases. In resource-limited countries, the need to tackle a broader range of overlapping comorbid diseases is growing. Tuberculosis and HIV/AIDS persist as global emergencies. The lethal interaction between tuberculosis and HIV coinfection in adults, children, and pregnant women in sub-Saharan Africa exemplifies the need for well integrated approaches to disease management and control. Furthermore, links between diabetes mellitus, smoking, alcoholism, chronic lung diseases, cancer, immunosuppressive treatment, malnutrition, and tuberculosis are well recognised. Here, we focus on interactions, synergies, and challenges of integration of tuberculosis care with management strategies for non-communicable and communicable diseases without eroding the functionality of existing national programmes for tuberculosis. The need for sustained and increased funding for these initiatives is greater than ever and requires increased political and funder commitment.

Assessment of the Xpert MTB/RIF assay for diagnosis of tuberculosis with gastric lavage aspirates in children in sub-Saharan Africa: a prospective descriptive study

BACKGROUND

Rapid and accurate diagnosis of pulmonary tuberculosis in children remains challenging because of difficulties in obtaining sputum samples and the paucibacillary nature of the disease. The Xpert MTB/RIF assay is useful for rapid diagnosis of childhood tuberculosis with sputum and nasopharyngeal samples. We assessed this assay for the detection of tuberculosis and multidrug resistant (MDR) tuberculosis with gastric lavage aspirate (GLA) samples in children admitted to hospital.

METHODS

We did a prospective study to assess the sensitivity and specificity of the Xpert MTB/RIF assay with GLA samples for the detection of pulmonary tuberculosis and MDR tuberculosis in new paediatric inpatient admissions at the University Teaching Hospital, Lusaka, Zambia. Children aged 15 years or younger were recruited between June, 2011, and May, 2012. GLA and sputum were analysed by standard smear-microscopy, mycobacterial growth indicator tube (MGIT) culture, MGIT drug-susceptibility testing, and the Xpert MTB/RIF assay. Sensitivity of the Xpert MTB/RIF assay was assessed with the Pearson χ(2) or Fishers exact test.

FINDINGS

Of 930 children, 142 produced sputum and GLA was obtained from 788 non-sputum producers. Culture-positive tuberculosis was identified in 58 (6·2%) of 930 children: ten from sputum producers and 48 from GLA of non-sputum producers. The sensitivity and specificity of the Xpert MTB/RIF assay were similar: sensitivity was 68·8% (95% CI 53·6-80·9) for GLA versus 90·0% (54·1-99·5; p=0·1649) for sputum samples; specificity was 99·3% (98·3-99·8) for GLA and 98·5% (94·1-99·7; p=0·2871) for sputum samples. The Xpert MTB/RIF assay detected an extra 28 tuberculosis cases compared with smear microscopy and was significantly more sensitive than smear microscopy for both sputum (90·0% [54·1-99·5] vs 30·0% [8·1-64·6], p=0·01) and GLA (68·8% [53·6-80·9] vs 25·0% [14·1-40·0], p<0·0001). The assay load did not differ significantly by sample type (p=0·791). 22 children were infected with HIV and tuberculosis and significant differences in assay performance could not be detected when stratifying by HIV status for either sample type. The Xpert MTB/RIF assay detected rifampicin resistance in three GLA samples: two confirmed as MDR tuberculosis and one false positive.

INTERPRETATION

Analyses of GLA samples with the Xpert MTB/RIF assay is a sensitive and specific method for rapid diagnosis of pulmonary tuberculosis in children who cannot produce sputum. The single site nature of our study invites caution.

FUNDING

European Commission, European Developing Countries Clinical Trials Partnership, and UBS Optimus Foundation.

Leprosy trends in Zambia 1991-2009

OBJECTIVE

To document leprosy trends in Zambia over the past two decades to ascertain the importance of leprosy as a health problem in Zambia.

METHODS

Retrospective study covering the period 1991-2009 of routine national leprosy surveillance data, published national programme review reports and desk reviews of in-country TB reports.

RESULTS

Data reports were available for all the years under study apart from years 2001, 2002 and 2006. The Leprosy case notification rates (CNR) declined from 2.73/10 000 population in 1991 to 0.43/10 000 population in 2009. The general leprosy burden showed a downward trend for both adults and children. Leprosy case burden dropped from approximately 18 000 cases in 1980 to only about 1000 cases in 1996, and by the year 2000, the prevalence rates had fallen to 0.67/10 000 population. There were more multibacillary cases of leprosy than pauci-bacillary cases. Several major gaps in data recording, entry and surveillance were identified. Data on disaggregation by gender, HIV status or geographical origin were not available.

CONCLUSION

Whilst Zambia has achieved WHO targets for leprosy control, leprosy prevalence data from Zambia may not reflect real situation because of poor data recording and surveillance. Greater investment into infrastructure and training are required for more accurate surveillance of leprosy in Zambia.

Evaluation of the burden of unsuspected pulmonary tuberculosis and co-morbidity with non-communicable diseases in sputum producing adult inpatients

BACKGROUND

A high burden of tuberculosis (TB) occurs in sub-Saharan African countries and many cases of active TB and drug-resistant TB remain undiagnosed. Tertiary care hospitals provide an opportunity to study TB co-morbidity with non-communicable and other communicable diseases (NCDs/CDs). We evaluated the burden of undiagnosed pulmonary TB and multi-drug resistant TB in adult inpatients, regardless of their primary admission diagnosis, in a tertiary referral centre.

METHODOLOGY/PRINCIPAL FINDINGS

In this prospective study, newly admitted adult inpatients able to produce sputum at the University Teaching Hospital, Lusaka, Zambia, were screened for pulmonary TB using fluorescent smear microscopy and automated liquid culture. The burden of pulmonary TB, unsuspected TB, TB co-morbidity with NCDs and CDs was determined. Sputum was analysed from 900 inpatients (70.6% HIV infected) 277 (30.8%) non-TB suspects, 286 (31.8%) TB suspects and 337 (37.4%) were already receiving TB treatment. 202/900 (22.4%) of patients had culture confirmed TB. TB co-morbidity was detected in 20/275 (7.3%) NCD patients, significantly associated with diabetes (P = 0.006, OR 6.571, 95%CI: 1.706-25.3). 27/202 (13.4%) TB cases were unsuspected. There were 18 confirmed cases of MDR-TB, 5 of which were unsuspected.

CONCLUSIONS/SIGNIFICANCE

A large burden of unsuspected pulmonary TB co-morbidity exists in inpatients with NCDs and other CDs. Pro-active sputum screening of all inpatients in tertiary referral centres in high TB endemic countries is recommended. The scale of the problem of undiagnosed MDR-TB in inpatients requires further study.

Evaluation of the Xpert MTB/RIF assay at a tertiary care referral hospital in a setting where tuberculosis and HIV infection are highly endemic

BACKGROUND. There were 1.45 million deaths from tuberculosis in 2011. A substantial proportion of active pulmonary tuberculosis cases in countries where tuberculosis, human immunodeficiency virus (HIV) infection, and AIDS are highly endemic remain undiagnosed because of the reliance on sputum-smear microscopy. This study evaluated the performance of the Xpert MTB/RIF assay at a tertiary care referral center in Zambia, a country where the burden of tuberculosis and HIV infection is high. METHODS. A total of 881 adult inpatients admitted to University Teaching Hospital in Lusaka who were able to produce sputum were enrolled and analyzed in the study, irrespective of admission diagnosis. Sputum specimens were analyzed by fluorescence smear microscopy, the Xpert MTB/RIF assay, mycobacterial growth indicator tube (MGIT) culture,and MGIT drug-susceptibility testing. The sensitivity and specificity of the Xpert MTB/RIF assay were evaluated using culture as the gold standard. RESULTS. Culture-confirmed tuberculosis was found in 201 of 881 patients (22.8%). The specificity of the Xpert MTB/RIF assay was 95.0% (95% confidence interval [CI], 92.4%–96.8%),and the sensitivity was 86.1% (95% CI, 80.3%–90.4%). In sputum smear–negative, culture-positive cases, the assay was 74.7% sensitive (95% CI, 64.6%–82.8%), identifying 71 additional tuberculosis cases that were not detected by smear microscopy.A total of 18 of 111 patients with tuberculosis who were tested (16.2%) had multidrug-resistant (MDR) tuberculosis.The sensitivity and specificity of the Xpert MTB/RIF assay for detecting culture-confirmed, rifampicin-resistant tuberculosis was 81.3% (95% CI, 53.7%–95.0%) and 97.5% (95% CI,90.4%–99.6%), respectively. CONCLUSIONS. The Xpert MTB/RIF assay performs better than smear microscopy in an inpatient setting in a country where tuberculosis and HIV infection are highly endemic. Assessment of its usefulness and cost-effectiveness for increased detection of tuberculosis cases missed by sputum smear and for concomitant screening for MDR tuberculosis among adult inpatients attending tertiary care referral centers in other countries with a high burden of tuberculosis and HIV infection is warranted [corrected].

Tuberculosis diagnostics and biomarkers: needs, challenges, recent advances, and opportunities

Tuberculosis is unique among the major infectious diseases in that it lacks accurate rapid point-of-care diagnostic tests. Failure to control the spread of tuberculosis is largely due to our inability to detect and treat all infectious cases of pulmonary tuberculosis in a timely fashion, allowing continued Mycobacterium tuberculosis transmission within communities. Currently recommended gold-standard diagnostic tests for tuberculosis are laboratory based, and multiple investigations may be necessary over a period of weeks or months before a diagnosis is made. Several new diagnostic tests have recently become available for detecting active tuberculosis disease, screening for latent M. tuberculosis infection, and identifying drug-resistant strains of M. tuberculosis. However, progress toward a robust point-of-care test has been limited, and novel biomarker discovery remains challenging. In the absence of effective prevention strategies, high rates of early case detection and subsequent cure are required for global tuberculosis control. Early case detection is dependent on test accuracy, accessibility, cost, and complexity, but also depends on the political will and funder investment to deliver optimal, sustainable care to those worst affected by the tuberculosis and human immunodeficiency virus epidemics. This review highlights unanswered questions, challenges, recent advances, unresolved operational and technical issues, needs, and opportunities related to tuberculosis diagnostics.

Drug-resistant tuberculosis--current dilemmas, unanswered questions, challenges, and priority needs

Tuberculosis was declared a global emergency by the World Health Organization (WHO) in 1993. Following the declaration and the promotion in 1995 of directly observed treatment short course (DOTS), a cost-effective strategy to contain the tuberculosis epidemic, nearly 7 million lives have been saved compared with the pre-DOTS era, high cure rates have been achieved in most countries worldwide, and the global incidence of tuberculosis has been in a slow decline since the early 2000s. However, the emergence and spread of multidrug-resistant (MDR) tuberculosis, extensively drug-resistant (XDR) tuberculosis, and more recently, totally drug-resistant tuberculosis pose a threat to global tuberculosis control. Multidrug-resistant tuberculosis is a man-made problem. Laboratory facilities for drug susceptibility testing are inadequate in most tuberculosis-endemic countries, especially in Africa; thus diagnosis is missed, routine surveillance is not implemented, and the actual numbers of global drug-resistant tuberculosis cases have yet to be estimated. This exposes an ominous situation and reveals an urgent need for commitment by national programs to health system improvement because the response to MDR tuberculosis requires strong health services in general. Multidrug-resistant tuberculosis and XDR tuberculosis greatly complicate patient management within resource-poor national tuberculosis programs, reducing treatment efficacy and increasing the cost of treatment to the extent that it could bankrupt healthcare financing in tuberculosis-endemic areas. Why, despite nearly 20 years of WHO-promoted activity and >12 years of MDR tuberculosis-specific activity, has the country response to the drug-resistant tuberculosis epidemic been so ineffectual? The current dilemmas, unanswered questions, operational issues, challenges, and priority needs for global drug resistance screening and surveillance, improved treatment regimens, and management of outcomes and prevention of DR tuberculosis are discussed.

Scale-up of services and research priorities for diagnosis, management, and control of tuberculosis: a call to action

The Millennium Development Goal target for tuberculosis control is to halt the spread of tuberculosis by 2015, and begin to reverse the worldwide incidence. After the introduction of standard control practices in 1995, 36 million people were cured and about 6 million deaths were averted. However, substantial scientific advances and innovative solutions are urgently needed together with creative new strategies. Strong international and national political commitment is essential. Urgent action is needed by national governments to fund their own programmes, and for the G8 countries and other donor governments and organisations to support governmental and non-governmental efforts. To foster the global need for urgent action to control the tuberculosis epidemic, The Lancet, in collaboration with the Stop TB Partnership, WHO, Global Fund to Fight AIDS, Tuberculosis and Malaria, and the experts participating in this Series, is launching The Lancet TB Observatory, which will assess and monitor progress in tuberculosis control and research, assess domestic and global financing, regularly disseminate information, and advocate for intensified efforts with stakeholders at all levels.

Tuberculosis in association with HIV/AIDS emerges as a major nonobstetric cause of maternal mortality in Sub-Saharan Africa

Every year, approximately 250,000 African women die during pregnancy, delivery, or the puerperium. Maternal mortality rates due to infectious diseases in Sub-Saharan Africa now supersede mortality from obstetric causes. Evidence is accumulating that tuberculosis associated with HIV/AIDS, malaria, sepsis, and other opportunistic infections are the main infectious causes of maternal deaths. Screening for these killer infections within prenatal healthcare programs is essential at this stage to prevent and treat causes of maternal mortality. The combination of proven effective interventions that avert the greatest number of maternal deaths should be prioritized and expanded to cover the greatest number of women at risk, and incorporated into a "prophylaxis and treatment community package of care." The effectiveness of these "packages of care" will need to be determined subsequently. Maternal deaths from tuberculosis are now on the increase in the UK, and due diligence and watchful surveillance are required in European prenatal services.

The biosocial dynamics of tuberculosis

The declaration by the WHO of tuberculosis as a 'global emergency' illustrates the paradox of tuberculosis. The treatment of this disease is a good example of 'evidence-based medicine', having been fine-tuned by numerous clinical trials. Modern short-course anti-tuberculosis therapy is among the most effective and cost-effective ways of saving and prolonging human life; yet, this disease is more prevalent today than in the days before the advent of effective therapy and is currently the cause of one in seven deaths and one in four preventable deaths among young adults. It would seem that something has gone seriously wrong and, to shed light on the cause, it is necessary to take a very broad historical look at the changing trends in the behaviour of the disease in communities worldwide and the attitudes of the various communities to the disease in their midst, not just to understand past mistakes, but to make sure we do not make the same mistakes now and in the future.

Role of co-trimoxazole prophylaxis in reducing mortality in HIV infected adults being treated for tuberculosis: randomised clinical trial

OBJECTIVE

To assess the impact of prophylactic oral co-trimoxazole in reducing mortality in HIV positive Zambian adults being treated for pulmonary tuberculosis.

DESIGN

Double blind placebo controlled randomised clinical trial.

PARTICIPANTS

Two groups of antiretroviral treatment naive adults with HIV infection: patients newly diagnosed as having tuberculosis and receiving tuberculosis treatment either for the first time or for retreatment after relapse; previously treated patients not receiving treatment.

INTERVENTION

Oral co-trimoxazole or matching placebo daily. Primary outcome measures Time to death and occurrence of serious adverse events related to study drug.

RESULTS

1003 patients were randomised: 835 (416 co-trimoxazole, 419 placebo) were receiving treatment for tuberculosis, 762 (376 co-trimoxazole, 386 placebo) of them newly diagnosed previously untreated patients and 73 (40 co-trimoxazole, 33 placebo) receiving a retreatment regimen; 168 (84 co-trimoxazole, 84 placebo) were not on treatment but had received treatment in the past. Of 835 participants receiving tuberculosis treatment, follow-up information was available for 757, with a total of 1012.6 person years of follow-up. A total of 310 (147 co-trimoxazole, 163 placebo) participants died, corresponding to death rates of 27.3 and 34.4 per 100 person years. In the Cox regression analysis, the hazard ratio for death (co-trimoxazole:placebo) was 0.79 (95% confidence interval 0.63 to 0.99). The effect of co-trimoxazole waned with time, possibly owing to falling adherence levels; in a per protocol analysis based on patients who spent at least 90% of their time at risk supplied with study drug, the hazard ratio was 0.65 (0.45 to 0.93).

CONCLUSIONS

Prophylaxis with co-trimoxazole reduces mortality in HIV infected adults with pulmonary tuberculosis. Co-trimoxazole was generally safe and well tolerated.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN15281875.

Treatment of tuberculosis: present status and future prospects

Over recent years, tuberculosis (TB) and disease caused by human immunodeficiency virus (HIV) have merged in a synergistic pandemic. The number of new cases of TB is stabilizing and declining, except in countries with a high prevalence of HIV infection. In these countries, where HIV is driving an increase in the TB burden, the capacity of the current tools and strategies to reduce the burden has been exceeded. This paper summarizes the current status of TB management and describes recent thinking and strategy adjustments required for the control of TB in settings of high HIV prevalence. We review the information on anti-TB drugs that is available in the public domain and highlight the need for continued and concerted efforts (including financial, human and infrastructural investments) for the development of new strategies and anti-TB agents.