Classification of early tuberculosis states to guide research for improved care and prevention: an international Delphi consensus exercise

The current active-latent paradigm of tuberculosis largely neglects the documented spectrum of disease. Inconsistency with regard to definitions, terminology, and diagnostic criteria for different tuberculosis states has limited the progress in research and product development that are needed to achieve tuberculosis elimination. We aimed to develop a new framework of classification for tuberculosis that accommodates key disease states but is sufficiently simple to support pragmatic research and implementation. Through an international Delphi exercise that involved 71 participants representing a wide range of disciplines, sectors, income settings, and geographies, consensus was reached on a set of conceptual states, related terminology, and research gaps. The International Consensus for Early TB (ICE-TB) framework distinguishes disease from infection by the presence of macroscopic pathology and defines two subclinical and two clinical tuberculosis states on the basis of reported symptoms or signs of tuberculosis, further differentiated by likely infectiousness. The presence of viable Mycobacterium tuberculosis and an associated host response are prerequisites for all states of infection and disease. Our framework provides a clear direction for tuberculosis research, which will, in time, improve tuberculosis clinical care and elimination policies.

A SARS-CoV-2 coronavirus nucleocapsid protein antigen-detecting lateral flow assay

Inexpensive, simple, rapid diagnostics are necessary for efficient detection, treatment, and mitigation of COVID-19. Assays for SARS-CoV2 using reverse transcription polymerase chain reaction (RT-PCR) offer good sensitivity and excellent specificity, but are expensive, slowed by transport to centralized testing laboratories, and often unavailable. Antigen-based assays are inexpensive and can be rapidly mass-produced and deployed at point-of-care, with lateral flow assays (LFAs) being the most common format. While various manufacturers have produced commercially available SARS-Cov2 antigen LFAs, access to validated tests remains difficult or cost prohibitive in low-and middle-income countries. Herein, we present a visually read open-access LFA (OA-LFA) using commercially-available antibodies and materials for the detection of SARS-CoV-2. The LFA yielded a Limit of Detection (LOD) of 4 TCID50/swab of gamma irradiated SARS-CoV-2 virus, meeting the acceptable analytical sensitivity outlined by in World Health Organization target product profile. The open-source architecture presented in this manuscript provides a template for manufacturers around the globe to rapidly design a SARS-CoV2 antigen test.

Antibody Screening Results for Anti-Nucleocapsid Antibodies Toward the Development of a Lateral Flow Assay to Detect SARS-CoV-2 Nucleocapsid Protein

The global COVID-19 pandemic has created an urgent demand for large numbers of inexpensive, accurate, rapid, point-of-care diagnostic tests. Analyte-based assays are suitably rapid and inexpensive and can be rapidly mass-produced, but for sufficiently accurate performance, they require highly optimized antibodies and assay conditions. We used an automated liquid handling system, customized to handle arrays of lateral flow (immuno)assays (LFAs) in a high-throughput screen, to identify anti-nucleocapsid antibodies that will perform optimally in an LFA. We tested 1021 anti-nucleocapsid antibody pairs as LFA capture and detection reagents with the goal of highlighting pairs that have the greatest affinity for the nucleocapsid protein of SARS-CoV-2 within the LFA format. In contrast to traditional antibody screening methods (e.g., ELISA, bio-layer interferometry), the method described here integrates real-time reaction kinetics with transport in, and immobilization directly onto, nitrocellulose. We have identified several candidate antibody pairs that are suitable for further development of an LFA for SARS-CoV-2.

Screening Antibodies Raised against the Spike Glycoprotein of SARS-CoV-2 to Support the Development of Rapid Antigen Assays

Severe acute respiratory coronavirus-2 (SARS-CoV-2) is a novel viral pathogen and therefore a challenge to accurately diagnose infection. Asymptomatic cases are common and so it is difficult to accurately identify infected cases to support surveillance and case detection. Diagnostic test developers are working to meet the global demand for accurate and rapid diagnostic tests to support disease management. However, the focus of many of these has been on molecular diagnostic tests, and more recently serologic tests, for use in primarily high-income countries. Low- and middle-income countries typically have very limited access to molecular diagnostic testing due to fewer resources. Serologic testing is an inappropriate surrogate as the early stages of infection are not detected and misdiagnosis will promote continued transmission. Detection of infection via direct antigen testing may allow for earlier diagnosis provided such a method is sensitive. Leading SARS-CoV-2 biomarkers include spike protein, nucleocapsid protein, envelope protein, and membrane protein. This research focuses on antibodies to SARS-CoV-2 spike protein due to the number of monoclonal antibodies that have been developed for therapeutic research but also have potential diagnostic value. In this study, we assessed the performance of antibodies to the spike glycoprotein, acquired from both commercial and private groups in multiplexed liquid immunoassays, with concurrent testing via a half-strip lateral flow assays (LFA) to indicate antibodies with potential in LFA development. These processes allow for the selection of pairs of high-affinity antispike antibodies that are suitable for liquid immunoassays and LFA, some of which with sensitivity into the low picogram range with the liquid immunoassay formats with no cross-reactivity to other coronavirus S antigens. Discrepancies in optimal ranking were observed with the top pairs used in the liquid and LFA formats. These findings can support the development of SARS-CoV-2 LFAs and diagnostic tools.

Screening Antibodies Raised against the Spike Glycoprotein of SARS-CoV-2 to Support the Development of Rapid Antigen Assays

Severe acute respiratory coronavirus-2 (SARS-CoV-2) is a novel viral pathogen and therefore a challenge to accurately diagnose infection. Asymptomatic cases are common and so it is difficult to accurately identify infected cases to support surveillance and case detection. Diagnostic test developers are working to meet the global demand for accurate and rapid diagnostic tests to support disease management. However, the focus of many of these has been on molecular diagnostic tests, and more recently serologic tests, for use in primarily high-income countries. Low- and middle-income countries typically have very limited access to molecular diagnostic testing due to fewer resources. Serologic testing is an inappropriate surrogate as the early stages of infection are not detected and misdiagnosis will promote continued transmission. Detection of infection via direct antigen testing may allow for earlier diagnosis provided such a method is sensitive. Leading SARS-CoV-2 biomarkers include spike protein, nucleocapsid protein, envelope protein, and membrane protein. This research focuses on antibodies to SARS-CoV-2 spike protein due to the number of monoclonal antibodies that have been developed for therapeutic research but also have potential diagnostic value. In this study, we assessed the performance of antibodies to the spike glycoprotein, acquired from both commercial and private groups in multiplexed liquid immunoassays, with concurrent testing via a half-strip lateral flow assays (LFA) to indicate antibodies with potential in LFA development. These processes allow for the selection of pairs of high-affinity antispike antibodies that are suitable for liquid immunoassays and LFA, some of which with sensitivity into the low picogram range with the liquid immunoassay formats with no cross-reactivity to other coronavirus S antigens. Discrepancies in optimal ranking were observed with the top pairs used in the liquid and LFA formats. These findings can support the development of SARS-CoV-2 LFAs and diagnostic tools.

Tuberculosis preventive treatment: the next chapter of tuberculosis elimination in India

The End TB Strategy envisions a world free of tuberculosis—zero deaths, disease and suffering due to tuberculosis by 2035. This requires reducing the global tuberculosis incidence from >1250 cases per million people to <100 cases per million people within the next two decades. Expanding testing and treatment of tuberculosis infection is critical to achieving this goal. In high-burden countries, like India, the implementation of tuberculosis preventive treatment (TPT) remains a low priority. In this analysis article, we explore potential challenges and solutions of implementing TPT in India. The next chapter in tuberculosis elimination in India will require cost-effective and sustainable interventions aimed at tuberculosis infection. This will require constant innovation, locally driven solutions to address the diverse and dynamic tuberculosis epidemiology and persistent programme monitoring and evaluation. As new tools, regimens and approaches emerge, midcourse adjustments to policy and practice must be adopted. The development and implementation of new tools and strategies will call for close collaboration between local, national and international partners—both public and private—national health authorities, non-governmental organisations, research community and the diagnostic and pharmaceutical industry. Leading by example, India can contribute to global knowledge through operational research and programmatic implementation for combating tuberculosis infection.

Unacceptable treatment outcomes and associated factors among India's initial cohorts of multidrug-resistant tuberculosis (MDR-TB) patients under the revised national TB control programme (2007-2011): Evidence leading to policy enhancement

Background

Globally, India has the world’s highest burden of multidrug-resistant tuberculosis (MDR-TB). Programmatic Management of Drug Resistant TB (PMDT) in India began in 2007 and nationwide coverage was achieved in early 2013. Poor initial microbiological outcomes under the Revised National Tuberculosis Control Programme (RNTCP) prompted detailed analysis. This is the first study on factors significantly associated with poor outcomes in MDR-TB patients treated under the RNTCP.

Objective

To evaluate initial sputum culture conversion, culture reversion and final treatment outcomes among MDR-TB patients registered in India from 2007 to early 2011 who were treated with a standard 24-month regimen under daily-observed treatment.

Methods

This is a retrospective cohort study. Clinical and microbiological data were abstracted from PMDT records. Initial sputum culture conversion, culture reversion and treatment outcomes were defined by country adaptation of the standard WHO definitions (2008). Cox proportional hazards modeling with logistic regression, multinomial logistic regression and adjusted odds ratio was used to evaluate factors associated with interim and final outcomes respectively, controlling for demographic and clinical characteristics.

Results

In the cohort of 3712 MDR-TB patients, 2735 (73.6%) had initial sputum culture conversion at 100 median days (IQR 92–125), of which 506 (18.5%) had culture reversion at 279 median days (IQR 202–381). Treatment outcomes were available for 2264 (60.9%) patients while 1448 (39.0%) patients were still on treatment or yet to have a definite outcome at the time of analysis. Of 2264 patients, 781 (34.5%) had treatment success, 644 (28.4%) died, 670 (29.6%) were lost to follow up, 169 (7.5%) experienced treatment failure or were changed to XDR-TB treatment. Factors significantly associated with either culture non-conversion, culture reversion and/or unfavorable treatment outcomes were baseline BMI < 18; ≥ seven missed doses in intensive phase (IP) and continuation phase (CP); cavitary disease; prior treatment episodes characterized by re-treatment regimen taken twice, longer duration and more episodes of treatment; any weight loss during treatment; males and additional resistance to first line drugs (Ethambutol, Streptomycin). In a subgroup of 104 MDR-TB patients, 62 (59.6%) had Ofloxacin resistance among whom only 25.8% had treatment success, half of the success (54.8%) seen in Ofloxacin sensitive patients. Baseline susceptibility to Ofloxacin (HR 2.04) and Kanamycin (HR 4.55) significantly doubled and quadrupled the chances for culture conversion respectively while baseline susceptibility to Ofloxacin (AOR 0.37) also significantly reduced the odds of unfavorable treatment outcomes (p value ≤0.05) in multinomial logistic regression model.

Conclusion

India’s initial MDR-TB patients’ cohort treated under the RNTCP experienced poor treatment outcomes. To address the factors associated with poor treatment outcomes revealed in our study, a systematic multi-pronged approach would be needed. A series of policies and interventions have been developed to address these factors to improve DR-TB treatment outcomes and are being scaled-up in India.

Airborne infection control in India: Baseline assessment of health facilities

BACKGROUND

Tuberculosis transmission in health care settings represents a major public health problem. In 2010, national airborne infection control (AIC) guidelines were adopted in India. These guidelines included specific policies for TB prevention and control in health care settings. However, the feasibility and effectiveness of these guidelines have not been assessed in routine practice. This study aimed to conduct baseline assessments of AIC policies and practices within a convenience sample of 35 health care settings across 3 states in India and to assess the level of implementation at each facility after one year.

METHOD

A multi-agency, multidisciplinary panel of experts performed site visits using a standardized risk assessment tool to document current practices and review resource capacity. At the conclusion of each assessment, facility-specific recommendations were provided to improve AIC performance to align with national guidelines.

RESULT

Upon initial assessment, AIC systems were found to be poorly developed and implemented. Administrative controls were not commonly practiced and many departments needed renovation to achieve minimum environmental standards. One year after the baseline assessments, there were substantial improvements in both policy and practice.

CONCLUSION

A package of capacity building and systems development that followed national guidelines substantially improved implementation of AIC policies and practice.

Use of Xpert MTB/RIF in Decentralized Public Health Settings and Its Effect on Pulmonary TB and DR-TB Case Finding in India

Background

Xpert MTB/RIF, the first automated molecular test for tuberculosis, is transforming the diagnostic landscape in high-burden settings. This study assessed the impact of up-front Xpert MTB/RIF testing on detection of pulmonary tuberculosis (PTB) and rifampicin-resistant PTB (DR-TB) cases in India.

Methods

This demonstration study was implemented in 18 sub-district level TB programme units (TUs) in India in diverse geographic and demographic settings covering a population of 8.8 million. A baseline phase in 14 TUs captured programmatic baseline data, and an intervention phase in 18 TUs had Xpert MTB/RIF offered to all presumptive TB patients. We estimated changes in detection of TB and DR-TB, the former using binomial regression models to adjust for clustering and covariates.

Results

In the 14 study TUs, which participated in both phases, 10,675 and 70,556 presumptive TB patients were enrolled in the baseline and intervention phase, respectively, and 1,532 (14.4%) and 14,299 (20.3%) bacteriologically confirmed PTB cases were detected. The implementation of Xpert MTB/RIF was associated with increases in both notification rates of bacteriologically confirmed TB cases (adjusted incidence rate ratio [aIRR] 1.39; CI 1.18-1.64), and proportion of bacteriological confirmed TB cases among presumptive TB cases (adjusted risk ratio (aRR) 1.33; CI 1.6-1.52). Compared with the baseline strategy of selective drug-susceptibility testing only for PTB cases at high risk of drug-resistant TB, Xpert MTB/RIF implementation increased rifampicin resistant TB case detection by over fivefold. Among, 2765 rifampicin resistance cases detected, 1055 were retested with conventional drug susceptibility testing (DST). Positive predictive value (PPV) of rifampicin resistance detected by Xpert MTB/RIF was 94.7% (CI 91.3-98.1), in comparison to conventional DST.

Conclusion

Introduction of Xpert MTB/RIF as initial diagnostic test for TB in public health facilities significantly increased case-notification rates of all bacteriologically confirmed TB by 39% and rifampicin-resistant TB case notification by fivefold.

A multi-site validation in India of the line probe assay for the rapid diagnosis of multi-drug resistant tuberculosis directly from sputum specimens

Rifampicin (R) and isoniazid (H) are key first-line anti-tuberculosis drugs. Failure to detect resistance to these two drugs early results in treatment failure and poor clinical outcomes. The study purpose was to validate the use of the GenoType MTBDRplus line probe assay (LPA) to detect resistance to R and H in Mycobacterium tuberculosis strains directly from smear-positive sputum samples in India.

Method

Smear positive sputum specimens from 320 patients were subjected to LPA and results compared against those from conventional Lowenstein Jensen (LJ) culture and drug susceptibility testing (C&DST). All specimens with discordant R DST results were subjected to either sequencing of the rpoB gene and/or repeat DST on liquid culture (MGIT 960) at a National Reference Laboratory.

Results

Significantly higher proportion of interpretable results were observed with LPA compared to LJ C&DST (94% vs. 80%, p-value <0.01). A total of 248 patients had both LJ and LPA DST results available; 232 (93.5%) had concordant R DST results. Among the 16 discordant R DST results, 13 (81%) were resolved in agreement with LPA results. Final LPA performance characteristics were sensitivity 96% (CI: 90%–98%), specificity 99% (CI: 95%–99%), positive predictive value 99% (CI: 95%–99%), and negative predictive value 95% (CI: 89%–98%). The median turnaround testing time, including specimen transportation time, on LPA was 11 days as compared with 89 days for LJ C&DST.

Conclusions

LPA proved highly accurate in the rapid detection of R resistance. The reduction in time to diagnosis may potentially enable earlier commencement of the appropriate drug therapy, leading to some reduction of transmission of drug-resistant strains.

Tuberculosis management practices by private practitioners in Andhra Pradesh, India

Setting

Private medical practitioners in Visakhapatnam district, Andhra Pradesh, India.

Objectives

To evaluate self-reported TB diagnostic and treatment practices amongst private medical practitioners against benchmark practices articulated in the International Standards of Tuberculosis Care (ISTC), and factors associated with compliance with ISTC.

Design

Cross- sectional survey using semi-structured interviews.

Results

Of 296 randomly selected private practitioners, 201 (68%) were assessed for compliance to ISTC diagnostic and treatment standards in TB management. Only 11 (6%) followed a combination of 6 diagnostic standards together and only 1 followed a combination of all seven treatment standards together. There were 28 (14%) private practitioners who complied with a combination of three core ISTC (cough for tuberculosis suspects, sputum smear examination and use of standardized treatment). Higher ISTC compliance was associated with caring for more than 20 TB patients annually, prior sensitization to TB control guidelines, and practice of alternate systems of medicine.

Conclusion

Few private practitioners in Visakhapatnam, India reported TB diagnostic and treatment practices that met ISTC. Better engagement of the private sector is urgently required to improve TB management practices and to prevent diagnostic delay and drug resistance.

Global guidelines for treatment of tuberculosis among persons living with HIV: unresolved issues

The Revised National Tuberculosis Control Programme (RNTCP) in India uses a fully intermittent thrice-weekly rifampicin-containing regimen for all tuberculosis (TB) patients, including those who are human immunodeficiency virus (HIV) infected, whereas the World Health Organization (WHO) recommends daily anti-tuberculosis treatment at least during the intensive phase. The WHO recommendation was based on the results of a meta-analysis demonstrating increased risk of recurrence and failure among HIV-infected TB patients receiving intermittent TB treatment compared to a daily regimen. Review of the primary evidence indicates limited, low-quality information on intermittency, mostly from observational studies in the pre-antiretroviral treatment (ART) era. Molecular epidemiology in India indicates that most of the recurrences and many of the failures result from exogenous re-infection, suggesting poor infection control and high transmission rather than poor regimen efficacy. Subsequently published studies have shown acceptable treatment outcomes among HIV-infected TB patients receiving intermittent anti-tuberculosis regimens with concomitant ART. Treatment outcomes among HIV-infected TB patients treated under programmatic conditions show low failure rates but high case fatality; death has been associated with lack of ART. The highest priority is therefore to reduce mortality by linking all HIV-infected TB patients to ART. While urgently seeking to reduce death rates among HIV-infected TB patients, given the poor evidence for change and operational advantages of an intermittent regimen, the RNTCP intends to collect the necessary evidence to inform national policy decisions through randomised clinical trials.

Feasibility and effectiveness of provider initiated HIV testing and counseling of TB suspects in Vizianagaram district, South India

Background

Though internationally recommended, provider initiated HIV testing and counseling (PITC) of persons suspected of tuberculosis (TB) is not a policy in India; HIV seroprevalence among TB suspects has never been reported. The current policy of PITC for diagnosed TB cases may limit opportunities of early HIV diagnosis and treatment. We determined HIV seroprevalence among persons suspected of TB and assessed feasibility and effectiveness of PITC implementation at this earlier stage in the TB diagnostic pathway.

Methods

All adults examined for diagnostic sputum microscopy (TB suspects) in Vizianagaram district (population 2.5 million), in November-December 2010, were offered voluntary HIV counseling and testing (VCT) and assessed for TB diagnosis.

Results

Of 2918 eligible TB suspects, 2465(85%) consented to VCT. Among these, 246(10%) were HIV-positive. Of the 246, 84(34%) were newly diagnosed as HIV (HIV status not known previously). To detect a new case of HIV infection, the number needed to screen (NNS) was 26 among ‘TB suspects’, comparable to that among ‘TB patients’. Among suspects aged 25–54 years, not diagnosed as TB, the NNS was 17.

Conclusion

The seroprevalence of HIV among ‘TB suspects’ was as high as that among ‘TB patients’. Implementation of PITC among TB suspects was feasible and effective, detecting a large number of new HIV cases with minimal additional workload on staff of HIV testing centre. HIV testing of TB suspects aged 25–54 years demonstrated higher yield for a given effort, and should be considered by policy makers at least in settings with high HIV prevalence.

Large-scale public-private partnership for improving TB-HIV services for high-risk groups in India

In India, the Revised National Tuberculosis Control Programme and a large-scale human immunodeficiency virus (HIV) prevention project partnered to deliver enhanced TB screening services for HIV high-risk groups. Between July 2007 and September 2008, 134 non-governmental organisations (NGOs) operating 412 clinics and community-based outreach services, screened 124 371 high-risk individuals and referred 3749 (3.01%) for TB diagnosis. Of these, 849 (23%) were diagnosed with TB. India has translated this model into national policy through a public-sector funded TB-HIV partnership scheme for NGOs serving high-risk groups.

National estimate of HIV seroprevalence among tuberculosis patients in India

The national estimate for human immunodeficiency virus (HIV) prevalence among tuberculosis (TB) patients in India has previously been estimated indirectly from global data. To derive an improved national estimate from local data, we correlated district-level HIV surveillance data from antenatal clinics and TB diagnostic centres, and applied this correlation to state-level HIV prevalence estimates for the antenatal population. We estimate that among the 1.96 million incident TB cases in 2007, 4.85% (95%CI 4.12-5.73) or 95 240 (95%CI 80 730-112 478) were HIV-infected. With these estimates from local data, the national programme can better plan TB-HIV collaborative activities and monitor efforts to detect HIV infection in this large population.

Risk factors for treatment default among re-treatment tuberculosis patients in India, 2006

Setting

Under India's Revised National Tuberculosis Control Programme (RNTCP), >15% of previously-treated patients in the reported 2006 patient cohort defaulted from anti-tuberculosis treatment.

Objective

To assess the timing, characteristics, and risk factors for default amongst re-treatment TB patients.

Methodology

For this case-control study, in 90 randomly-selected programme units treatment records were abstracted from all 2006 defaulters from the RNTCP re-treatment regimen (cases), with one consecutively-selected non-defaulter per case. Patients who interrupted anti-tuberculosis treatment for >2 months were classified as defaulters.

Results

1,141 defaulters and 1,189 non-defaulters were included. The median duration of treatment prior to default was 81 days (25%–75% interquartile range 44–117 days) and documented retrieval efforts after treatment interruption were inadequate. Defaulters were more likely to have been male (adjusted odds ratio [aOR] 1.4, 95% confidence interval [CI] 1.2–1.7), have previously defaulted anti-tuberculosis treatment (aOR 1.3 95%CI 1.1–1.6], have previous treatment from non-RNTCP providers (AOR 1.3, 95%CI 1.0–1.6], or have public health facility-based treatment observation (aOR 1.3, 95%CI 1.1–1.6).

Conclusions

Amongst the large number of re-treatment patients in India, default occurs early and often. Improved pre-treatment counseling and community-based treatment provision may reduce default rates. Efforts to retrieve treatment interrupters prior to default require strengthening.

Perceptions of tuberculosis patients on provider-initiated HIV testing and counseling--a study from south India

Background

The acceptability and feasibility of provider-initiated HIV testing and counseling (PITC) in many settings across Asia with concentrated HIV epidemics is not known. A pilot study of the PITC policy undertaken within the public health care systems in two districts in India offered the opportunity to understand patient's perspectives on the process of referral for HIV testing and linking to HIV treatment and care.

Methods

We conducted a cross-sectional study of randomly selected TB patients registered by the TB control program between July and November 2007 in two districts in south India. Trained interviewers met patients shortly after TB diagnosis and administered a structured questionnaire. Patients were assessed regarding their experience with HIV status assessment, referral for counseling and testing, and for HIV-infected patients the counseling itself and subsequent referral for HIV treatment and care.

Results

Of the 568 interviewed TB patients, 455 (80%) reported being referred for HIV testing after they presented to the health facility for investigations or treatment for TB. Over half the respondents reported having to travel long distances and incurred financial difficulties in reaching the Integrated Counselling and Testing Centre (ICTC) and two-thirds had to make more than two visits. Only 48% reported having been counseled before the test. Of the 110 HIV-infected patients interviewed, (including 43 with previously-known positive HIV status and 67 detected by PITC), 89 (81%) reported being referred for anti-retroviral treatment (ART); 82 patients reached the ART centre but only 44 had been initiated on ART.

Conclusions

This study provides the first evidence from India that routine, provider-initiated voluntary HIV testing of TB patients is acceptable, feasible and can be achieved with very high efficiency under programmatic conditions. While PITC is useful in identifying new HIV-infected patients so that they can be successfully linked to ART, the convenience and proximity of testing centres, quality of HIV counseling, and efficiency of ART services need attention.

Feasibility of provider-initiated HIV testing and counselling of tuberculosis patients under the TB control programme in two districts of South India

Background

Provider-initiated HIV testing and counselling (PITC) is internationally recommended for tuberculosis (TB) patients, but the feasibility, effectiveness, and impact of this policy on the TB programme in India are unknown. We evaluated PITC of TB patients across two districts in India considered to have generalized HIV epidemics, Tiruchirappalli (population 2.5 million) and Mysore (population 2.8 million).

Methodology/Principal Findings

Starting June 2007, healthcare providers in both districts were instructed to ascertain HIV status for all TB patients, and refer those with unknown HIV status to the nearest Integrated Counselling and Testing Centre (ICTC)—often in the same facility—for counselling and voluntary HIV testing. All TB patients registered from June 2007 to March 2008 were followed prospectively. Field investigators assessed PITC practices and abstracted data from routine TB programme records and HIV counselling registers to determine the proportion of TB patients appropriately evaluated for HIV infection. Patient records were traced to determine the efficiency of referral links to HIV care and antiretroviral treatment (ART). Between July 2007 and March 2008, 5299 TB patients were registered in both study districts. Of the 4701 with unknown HIV status at the time of TB treatment initiation, 3368 (72%) were referred to an ICTC, and 3111 (66%) were newly tested for HIV. PITC implementation resulted in the ascertainment of HIV status for 3709/5299 (70%) of TB patients, and detected 200 cases with previously undiagnosed HIV infection. Overall, 468 (8.8%) of all registered TB patients were HIV-infected; 177 (37%) were documented to have also received any ART.

Conclusions

With implementation of PITC in India, HIV status was successfully ascertained for 70% of TB patients. Previously undiagnosed HIV-infection was detected in 6.4% of those TB patients newly tested, enabling referral for life-saving anti-retroviral treatment. ART uptake, however, was poor, suggesting that PITC implementation should include measures to strengthen and support ART referral, evaluation, and initiation.

Initial default among diagnosed sputum smear-positive pulmonary tuberculosis patients in Andhra Pradesh, India

BACKGROUND

Under the Indian Revised National TB Control Programme (RNTCP), smear-positive pulmonary tuberculosis (PTB) patients not confirmed as starting treatment are reported as 'initial defaulters'.

SETTING

Twenty districts of Andhra Pradesh State, India.

OBJECTIVE

To evaluate reasons for treatment non-initiation in smear-positive PTB patients diagnosed and reported as initial defaulters by the NTP.

DESIGN

A cross-sectional survey conducted of all reported initial defaulters during the period July-September 2006.

RESULTS

Of 1304 reported initial defaulters, 619 (47.5%) had been placed on treatment, having been incorrectly reported due to poor documentation of patients referred for treatment in the same district or whose treatment initiation was delayed until the subsequent quarter. Of the 685 (4.5% of the total diagnosed) who were confirmed initial defaulters, 350 (51%) were untraceable, 152 (22%) had died before treatment initiation, 38 (5.5%) were treated privately, 93 (13.5%) had other reasons (e.g., refusal of treatment, chronic case, etc.) and no data were available for 52 (8%).

CONCLUSIONS

Nearly 5% of smear-positive PTB patients diagnosed in the study period were confirmed as not having initiated treatment under the RNCTP. Improvements in address recording may assist efforts to retrieve these patients for treatment. Additional evaluations are needed of improved counselling of TB suspects to prevent initial default, and of reasons for death before treatment initiation.

Cost and cost-effectiveness of a public-private mix project in Kannur District, Kerala, India, 2001-2002

BACKGROUND

Little is known yet about the cost-effectiveness of public-private mix (PPM) collaborations for the delivery of tuberculosis (TB) diagnostic and treatment services.

DESIGN

We evaluated the cost and cost-effectiveness of a PPM project targeting private laboratories in Kannur district, India, from the perspective of the Revised National TB Control Programme (RNTCP). We estimated the cost per provider recruited and retained, the cost per additional patient notified under various effectiveness scenarios and the cost per additional patient successfully treated. Intervention cost data were abstracted from RNTCP records. Treatment costs were estimated based on RNTCP case management protocols.

RESULTS

The annual total estimated cost of the project was US$8712-$11611. The cost per private provider recruited varied between US$22 and US$54. The cost per additional pulmonary TB patient privately diagnosed was US$14-$18. In the most conservative scenario, the cost per additional patient notified was US$29-$36. The cost per new acid-fast bacilli-positive patient successfully treated was US$47-$51. Higher notification rates would improve cost-effectiveness.

CONCLUSIONS

Comparisons with public sector diagnostic costs are required to determine if this intervention remains economically attractive to the public health care system at different activity levels and to determine the supplemental resources needed if scale-up is pursued.

Public-private mix TB activities in Meerut, Uttar Pradesh, North India: delivering dots via collaboration with private providers and non-governmental organizations

BACKGROUND

We evaluated the contribution of public-private collaboration between the Indian tuberculosis (TB) programme and the private health sector (including non-governmental organizations and private providers) to TB case-detection and treatment outcomes in Meerut district, India.

METHODOLOGY

District TB registers from January 2001-June 2003 were reviewed.

RESULTS

The 2002 new AFB-positive case-notification rate (103/100,000 population) in Meerut exceeded national targets. Of the 7,062 new AFB-positive patients registered, 2,084 (29%) were detected at private sector microscopy and DOTS treatment centres; treatment outcomes met programme targets.

CONCLUSION

Public-private collaborations can be successfully implemented at the district level in India, and have the potential for substantial contributions to TB control efforts in India.

Low sensitivity of a whole-blood interferon-gamma release assay for detection of active tuberculosis

The sensitivity of an interferon-gamma assay (Quantiferon-TB Gold; Cellestis) was evaluated for the detection of tuberculosis among 242 persons with suspected tuberculosis in San Francisco, California. Thirty-seven subjects had culture-confirmed tuberculosis. Excluding 1 indeterminate result, 23 (64%; 95% confidence interval, 48%-78%) of 36 subjects had positive results using the QuantiFERON-TB Gold assay. The 64% sensitivity suggests that the QuantiFERON-TB Gold assay should not be used alone to exclude active tuberculosis.

Improving tuberculosis control through public-private collaboration in India: literature review

OBJECTIVE

To review the characteristics of public-private mix projects in India and their effect on case notification and treatment outcomes for tuberculosis.

DESIGN

Literature review.

DATA SOURCES

Review of surveillance records from Indian tuberculosis programme project, evaluation reports, and medical literature for public-private mix projects in India.

DATA EXTRACTION

Project characteristics, tuberculosis case notification of new patients with sputum smear results positive for acid fast bacilli, and treatment outcome.

DATA SYNTHESIS

Of 24 identified public-private mix projects, data were available from 14 (58%), involving private practitioners, corporations, and non-governmental organisations. In all reviewed projects, the public sector tuberculosis programme provided training and supervision of private providers. Among the five projects with available data on historical controls, case notification rates were higher after implementation of a public-private mix project. Among seven projects involving private practitioners, 2796 of 12 147 (23%) new patients positive for acid fast bacilli were attributed to private providers. Corporate based and non-governmental organisations served as the main source for tuberculosis programme services in seven project areas, detecting 9967 new patients positive for acid fast bacilli. In nine of 12 projects with data on treatment outcomes, private providers exceeded the programme target of 85% treatment success for new patients positive for acid fast bacilli.

CONCLUSIONS

Public-private mix activities were associated with increased case notification, while maintaining acceptable treatment outcomes. Collaborations between public and private providers of health care hold considerable potential to improve tuberculosis control in India.

A tuberculosis outbreak in a private-home family child care center in San Francisco, 2002 to 2004

BACKGROUND

Child care facilities are well known as sites of infectious disease transmission, and California child care facility licensure requirements include annual tuberculosis (TB) screening for on-site adults. In April 2004, we detected an adult with TB living in a private-home family child care center (child care center A).

METHODS

We reviewed patient medical records and conducted a contact investigation. The investigation included all persons at the child care center, the workplace and leisure contacts of the adult patient with TB, and the household contacts of secondary case patients. Contact names were obtained through patient interviews. A positive tuberculin skin test result was defined as induration of > or =5 mm. DNA fingerprints of Mycobacterium tuberculosis isolates were analyzed. Outbreak cases were those that had matching DNA fingerprint patterns or were linked epidemiologically, if DNA fingerprint results were not available.

RESULTS

Between August 2002 and July 2004, we detected 11 outbreak cases, including 9 (82%) among children (<18 years of age). All 11 outbreak patients lived or were cared for at child care center A. The 9 pediatric TB patients were young (<7 years of age), United States-born children of foreign-born parents, and 4 (44%) had positive cultures for M tuberculosis. Including isolates recovered from the 2 adult patients, all 6 M tuberculosis isolates shared identical, 7-band, DNA fingerprint patterns. The contact investigation identified 3 (33%) of the 9 pediatric cases; 2 (22%) presented with illness and 4 (44%) were detected by primary care providers during routine TB screening. Excluding case subjects, 36 (54%) of 67 named contacts had latent TB infection.

CONCLUSIONS

Provider adherence to locally adapted pediatric TB screening recommendations proved critical to outbreak control. TB screening compliance by the child care center and more aggressive source-case investigation by the TB program might have prevented or abated this large pediatric TB outbreak.

Improved tuberculosis case detection through public-private partnership and laboratory-based surveillance, Kannur District, Kerala, India, 2001-2002

BACKGROUND

Efforts to intensify global tuberculosis (TB) control are limited by difficulties in coordinating with private doctors. More than half of Indian TB patients may initially consult a private provider, but many are neither diagnosed accurately nor treated effectively. We established and evaluated a public-private partnership based on surveillance of TB detected in private laboratories and use of standardised directly observed treatment regimens.

METHODS

In one district, the governmental TB control programme offered training in microscopy to all large private sector laboratories, and educated private physicians on the importance of microscopy for TB diagnosis. We reviewed records from participating private laboratories and all publicly diagnosed patients.

RESULTS

Of 2328 pulmonary TB patients registered from July 2001 to December 2002, 404 (17%) were detected in the private sector. The annual new AFB-positive case notification rate increased by 21%, from 27.8/100,000 in 2000 to 33.5/100,000 in 2002. Surveillance at private laboratories found an additional 260 nonregistered AFB-positive patients.

CONCLUSIONS

This public-private partnership substantially increased TB case detection and established a sustainable framework for private sector involvement in TB control. In the setting of a strong public sector programme, the combination of active surveillance of private laboratories along with physician sensitisation is a promising approach to improve TB case detection.

Risk factors for death during tuberculosis treatment in Orel, Russia

SETTING AND METHODS

In Orel, high tuberculosis (TB) case fatality rates have persisted despite successful implementation of the World Health Organization (WHO) global TB control strategy. We conducted a case control study to identify risk factors for mortality among Orel TB patients reported from October 1999 through June 2001. Cases were patients who died within 8 months of treatment initiation. We analyzed data abstracted from medical records using conditional logistic regression.

RESULTS

Over the 21-month period, 63/1069 (5.9%) TB patients overall and 45/521 (8.6%) sputum smear-positive patients died during treatment. Compared to 192 controls, independent risk factors for death for both smear-positive and smear-negative patients included unemployment (adjusted odds ratio [AOR] 4.9, 95% confidence interval [CI] 1.9-12.9), homelessness (AOR 9.5, 95% CI 1.3-70.9), congestive heart failure (AOR 5.4, 95% CI 1.9-15.9), chronic lung disease (AOR 2.4, 95% CI 1.1-5.4), cancer (AOR 7.2, 95% CI 1.2-45.0), bilateral disease on chest X-ray (AOR 6.3, 95% CI 2.3-17.1), and hyperbilirubinemia (AOR 5.2, 95% CI 1.1-25.3). Among deaths, the median time from treatment initiation to death was 35 days.

CONCLUSIONS

The diagnosis and treatment of TB in suspects with the observed comorbidities and risk factors should be aggressively pursued. The association of unemployment and homelessness with mortality suggests a contribution of poverty to death during TB treatment.

Inhalational anthrax outbreak among postal workers, Washington, D.C., 2001

In October 2001, four cases of inhalational anthrax occurred in workers in a Washington, D.C., mail facility that processed envelopes containing Bacillus anthracis spores. We reviewed the envelopes' paths and obtained exposure histories and nasal swab cultures from postal workers. Environmental sampling was performed. A sample of employees was assessed for antibody concentrations to B. anthracis protective antigen. Case-patients worked on nonoverlapping shifts throughout the facility, suggesting multiple aerosolization events. Environmental sampling showed diffuse contamination of the facility. Potential workplace exposures were similar for the case-patients and the sample of workers. All nasal swab cultures and serum antibody tests were negative. Available tools could not identify subgroups of employees at higher risk for exposure or disease. Prophylaxis was necessary for all employees. To protect postal workers against bioterrorism, measures to reduce the risk of occupational exposure are necessary.