Health care providers acceptance of default prescribing of TB preventive treatment for people living with HIV in Malawi: a qualitative study

BACKGROUND

Tuberculosis (TB) preventive treatment (TPT) substantially reduces the risk of developing active TB for people living with HIV (PLHIV). We utilized a novel implementation strategy based on choice architecture (CAT) which makes TPT prescribing the default option. Through CAT, health care workers (HCWs) need to "opt-out" when choosing not to prescribe TPT to PLHIV. We assessed the prospective, concurrent, and retrospective acceptability of TPT prescribing among HCWs in Malawi who worked in clinics participating in a cluster randomized trial of the CAT intervention.

METHODS

28 in-depth semi-structured interviews were conducted with HCWs from control (standard prescribing approach) and intervention (CAT approach) clinics. The CAT approach was facilitated in intervention clinics using a default prescribing module built into the point-of-care HIV Electronic Medical Record (EMR) system. An interview guide for the qualitative CAT assessment was developed based on the theoretical framework of acceptability and on the normalization process theory. Thematic analysis was used to code the data, using NVivo 12 software.

RESULTS

We identified eight themes belonging to the three chronological constructs of acceptability. HCWs expressed no tension for changing the standard approach to TPT prescribing (prospective acceptability); however, those exposed to CAT described several advantages, including that it served as a reminder to prescribe TPT and routinized TPT prescribing (concurrent acceptability). Some felt that CAT may reduce HCW´s autonomy and might lead to inappropriate TPT prescribing (retrospective acceptability).

CONCLUSIONS

The default prescribing module for TPT has now been incorporated into the point-of-care EMR system nationally in Malawi. This seems to fit the acceptability of the HCWs. Moving forward, it is important to train HCWs on how the EMR can be leveraged to determine who is eligible for TPT and who is not, while acknowledging the autonomy of HCWs.

Factors associated with non-completion of TB preventive treatment in Brazil

BACKGROUND: Among Brazilian initiatives to scale up TB preventive therapy (TPT) are the adoption of the 3HP regimen (12 weekly doses of rifapentine and isoniazid [INH]) in 2021 and the implementation in 2018 of the TPT surveillance information system. Since then, 63% of the 76,000 eligible individuals notified completed TPT. Recommended regimens in this period were 6H, 9H (6 or 9 months of INH) and 4R (4 months of rifampicin).OBJECTIVE: To analyse the factors associated with TPT non-completion.METHODS: We analysed the cohort of TPT notifications from 2018 to 2020. Robust variance Poisson regression model was used to verify the association of TPT non-completion with sociodemographic, clinical and epidemiological variables.RESULTS: Of the 39,973 TPT notified in the study period, 8,534 (21.5%) were non-completed, of which 7,858 (92.1%) were lost to follow-up. Age 15-60 years (relative risk [RR] 1.27, 95% confidence interval [95% CI] 1.20-1.35), TPT with isoniazid (RR 1.40, 95% CI 1.19-1.64) and Black/mixed race (RR 1.17, 95% CI 1.09-1.25) were associated with a higher risk of non-completion.CONCLUSION: Individuals in situations of social and financial vulnerability such as being Black/pardo race, younger and on longer TPT regimens were more likely to be associated with TPT incompletion.

A scoping review of interventions to mitigate common non-communicable diseases among people with TB

BACKGROUND: Recommendations have been made to integrate screening for common non-communicable diseases (NCDs) within TB programs. However, we must ensure screening is tied to evidence-based interventions before scale-up. We aimed to map the existing evidence regarding interventions that address NCDs that most commonly affect people with TB.METHODS: We systematically searched PubMed, Medline, and Embase for studies that evaluated interventions to mitigate respiratory disease, cardiovascular disease, alcohol and substance use disorder, and mental health disorders among people with TB. We excluded studies that only screened for comorbidity but resulted in no further intervention. We also excluded studies focusing on smoking cessation interventions for which evidence-based guidelines are well established.RESULTS: The search identified 20 studies that met our inclusion criteria. The most commonly evaluated intervention was referral for diabetes care (6 studies). Other interventions included pulmonary rehabilitation (5 studies), care programs for alcohol use disorder (4 studies), and psychosocial support or individual counselling (5 studies).CONCLUSION: There is limited robust evidence to support identified interventions in changing individual outcomes, and a significant knowledge gap remains on the long-term durability of the interventions´ clinical benefit, reach, and effectiveness. Implementation research demonstrating feasibility and effectiveness is needed before scaling up.

Number needed to screen for TB in clinical, structural or occupational risk groups

BACKGROUND: Screening for active TB using active case-finding (ACF) may reduce TB incidence, prevalence, and mortality; however, yield of ACF interventions varies substantially across populations. We systematically reviewed studies reporting on ACF to calculate the number needed to screen (NNS) for groups at high risk for TB.METHODS: We conducted a literature search for studies reporting ACF for adults published between November 2010 and February 2020. We determined active TB prevalence detected through various screening strategies and calculated crude NNS for - TB confirmed using culture or Xpert^® MTB/RIF, and weighted mean NNS stratified by screening strategy, risk group, and country-level TB incidence.RESULTS: We screened 27,223 abstracts; 90 studies were included (41 in low/moderate and 49 in medium/high TB incidence settings). High-risk groups included inpatients, outpatients, people living with diabetes (PLWD), migrants, prison inmates, persons experiencing homelessness (PEH), healthcare workers, and miners. Screening strategies included symptom-based screening, chest X-ray and Xpert testing. NNS varied widely across and within incidence settings based on risk groups and screening methods. Screening tools with higher sensitivity (e.g., Xpert, CXR) were associated with lower NNS estimates.CONCLUSIONS: NNS for ACF strategies varies substantially between adult risk groups. Specific interventions should be tailored based on local epidemiology and costs.

Concomitant pulmonary disease is common among patients with extrapulmonary TB

BACKGROUND :

Microbiologic screening of extrapulmonary TB (EPTB) patients could inform recommendations for aerosol precautions and close contact prophylaxis. However, this is currently not routinely recommended in India. Therefore, we estimated the proportion of Indian patients with EPTB with microbiologic evidence of pulmonary TB (PTB).

METHODS :

We characterized baseline clinical, radiological and sputum microbiologic data of 885 adult and pediatric TB patients in Chennai and Pune, India, between March 2014 and November 2018.

RESULTS :

Of 277 patients with EPTB, enhanced screening led to the identification of 124 (45%) with concomitant PTB, including 53 (19%) who reported a cough >2 weeks; 158 (63%) had an abnormal CXR and 51 (19%) had a positive sputum for TB. Of 70 participants with a normal CXR and without any cough, 14 (20%) had a positive sputum for TB. Overall, the incremental yield of enhanced screening of patients with EPTB to identify concomitant PTB disease was 14% (95% CI 12–16).

CONCLUSIONS :

A high proportion of patients classified as EPTB in India have concomitant PTB. Our results support the need for improved symptom and CXR screening, and recommends routine sputum TB microbiology screening of all Indian patients with EPTB.

A systematic review of the number needed to screen for active TB among people living with HIV

BACKGROUND: Systematic screening for active TB is recommended for all people living with HIV (PLWH); however, case detection remains poor globally. We investigated the yield of active case finding (ACF) by calculating the number needed to screen (NNS) to detect a case of active TB among PLWH.METHODS: We identified studies reporting ACF for TB among PLWH published from November 2010 to February 2020. We calculated crude NNS for Xpert- or culture-confirmed TB and weighted mean NNS stratified by screening approach, population/risk group, and country TB burden.RESULTS: Of the 27,221 abstracts screened, we identified 58 studies eligible for inclusion, including 5 in low/moderate TB incidence settings and 53 in medium/high incidence settings. Populations screened for TB included inpatients, outpatients not receiving antiretroviral therapy (ART), outpatients receiving ART, those with CD4 < 200 cells/µL, children aged ≤15 years, pregnant PLWH, and PLWH in prisons. Screening tools included symptom-based screening, chest X-ray, C-reactive protein levels, and Xpert. The weighted mean NNS varied across groups but was consistently low, ranging from 4 among inpatients in moderate/high TB burden settings to 137 among pregnant PLWH in moderate/high TB burden settings.CONCLUSIONS: ACF is a high yield intervention among PLWH. Approaches to screening should be tailored to local epidemiological and health-system contexts, and sensitive screening tools such as Xpert should be implemented where feasible.

Unhealthy alcohol use independently associated with unfavorable TB treatment outcomes among Indian men

BACKGROUND: Approximately 10% of incident TB cases worldwide are attributable to alcohol. However, evidence associating alcohol with unfavorable TB treatment outcomes is weak.METHODS: We prospectively evaluated men (≥18 years) with pulmonary TB in India for up to 24 months to investigate the association between alcohol use and treatment outcomes. Unhealthy alcohol use was defined as a score of ≥4 on the Alcohol Use Disorders Identification Test-Concise (AUDIT-C) scale at entry. Unfavorable TB treatment outcomes included failure, recurrence, and all-cause mortality, analyzed as composite and independent endpoints.RESULTS: Among 751 men, we identified unhealthy alcohol use in 302 (40%). Median age was 39 years (IQR 28-50); 415 (55%) were underweight (defined as a body mass index [BMI] <18.5 kg/m²); and 198 (26%) experienced an unfavorable outcome. Unhealthy alcohol use was an independent risk factor for the composite unfavorable outcome (adjusted incidence rate ratio [aIRR] 1.47, 95% CI 1.05-2.06; P = 0.03) and death (aIRR 1.90, 95% CI 1.08-3.34; P = 0.03), specifically. We found significant interaction between AUDIT-C and BMI; underweight men with unhealthy alcohol use had increased risk of unfavorable outcomes (aIRR 2.22, 95% CI 1.44-3.44; P < 0.001) compared to men with BMI ≥18.5 kg/m² and AUDIT-C <4.CONCLUSION: Unhealthy alcohol use was independently associated with unfavorable TB treatment outcomes, highlighting the need for integrating effective alcohol interventions into TB care.

Choice architecture-based prescribing tool for TB preventive therapy: a pilot study in South Africa

Background

All people with HIV who screen negative for active tuberculosis (TB) should receive isoniazid preventive therapy (IPT). IPT implementation remains substantially below the 90% WHO target. This study sought to further understanding of IPT prescription by piloting a simplified prescribing approach.

Setting

Primary care clinics in Matlosana, South Africa.

Design

This was a mixed-methods implementation study.

Methods

Nine providers were recruited and underwent training on 2018 WHO guidelines. A simplified prescribing tool containing antiretroviral therapy (ART) and IPT prescriptions was introduced into the workflow for 2 weeks. Prescription data were collected from file review. Interviews were conducted with prescribers.

Results

During the study period, 41 patients were evaluated for ART initiation; 34 (83%) files used the simplified prescribing tool. Thirty-seven (90%) patients were eligible for same-day ART and IPT initiation, of whom 36 (97%) received IPT prescription. Qualitative interviews identified the following barriers to IPT prescription: cognitive burden, extensive documentation, limited management support, paucity of training, stock-outs, and patient-related factors. Provider acceptability of the tool was favorable, with unanimous recommendation to colleagues on the basis of streamlining documentation and reminding to prescribe.

Conclusions

This simplified prescribing device for IPT was feasible to implement. Streamlining documentation and reminding providers to prescribe can reduce work-flow barriers to IPT provision.

Delays and barriers to early treatment initiation for childhood tuberculosis in India

BACKGROUND: India accounts for 27% of global childhood tuberculosis (TB) burden. Understanding barriers to early diagnosis and treatment in children may improve care and outcomes.METHODS: A cross-sectional study was performed among 89 children initiated on anti-TB treatment from a public hospital in Pune during 2016, using a structured questionnaire and hospital records. Health care providers (HCPs) were defined as medical personnel consulted about the child's TB symptoms. Time-to-treatment initiation (TTI) was defined as the number of days between onset of TB symptoms and anti-TB treatment initiation. Based on Revised National TB Control Programme recommendations, delayed TTI was defined as >28 days.RESULTS: Sixty-seven (75%) of 89 enrolled children had significant TTI delays (median 51 days, interquartile range [IQR] 27-86). Sixty-six (74%) children visited 1-8 HCPs in the private sector before approaching the public sector. The median HCP delay was 28 days (IQR 10-75). Bacille Calmette-Guérin vaccination (aOR 10.96, P = 0.04) and loss of appetite (aOR 4.44, P = 0.04) were associated with delayed TTI.CONCLUSION: The majority of the children had TTI delays due to delays by HCPs in the private sector. Strengthening HCP competency in TB symptom screening and encouraging early referrals are crucial for rapid scaling up of early treatment initiation in childhood TB.

Mobile phone access and comfort: implications for HIV and tuberculosis care in India and South Africa

SETTING: India and South Africa shoulder the greatest burden of tuberculosis (TB) and human immunodeficiency virus (HIV) infection respectively, but care retention is suboptimal.OBJECTIVE: We conducted a study in Pune, India, and Matlosana, South Africa, 1) to identify the factors associated with mobile phone access and comfort of use, 2) to assess access patterns.DESIGN: A cross-sectional study assessed mobile phone access, and comfort; a longitudinal study assessed access patterns.RESULTS: We enrolled 261 participants: 136 in India and 125 in South Africa. Between 1 week and 6 months, participant contact decreased from 90% (n = 122) to 57% (n = 75) in India and from 93% (n = 116) to 70% (n = 88) in South Africa. In the latter, a reason for a clinic visit for HIV management was associated with 63% lower odds of contact than other priorities (e.g., diabetes mellitus, maternal health, TB). In India, 57% (n = 78) reported discomfort with texting; discomfort was higher in the unemployed (adjusted OR [aOR] 4.97, 95%CI 1.12-22.09) and those aged ≥35 years (aOR 1.10, 95%CI 1.04-1.16) participants, but lower in those with higher education (aOR 0.04, 95% CI 0.01-1.14). In South Africa, 91% (n = 114) reported comfort with texting.CONCLUSION: Mobile phone contact was poor at 6 months. While mHealth could transform TB-HIV care, alternative approaches may be needed for certain subpopulations.

Diabetes mellitus and tuberculosis in Korean adults: impact on tuberculosis incidence, recurrence and mortality

<sec id="st1"> <title>SETTING</title> The prevalence of diabetes mellitus (DM) worldwide is increasing markedly, and many countries with rising rates also have a high incidence rate of tuberculosis (TB). </sec> <sec id="st2"> <title>OBJECTIVE</title> To investigate the relationships of fasting serum glucose (FSG) and DM with TB incidence, recurrence and mortality risk in a prospective cohort study in South Korea. </sec> <sec id="st3"> <title>DESIGN</title> Our study comprised 1 267 564 Koreans who received health insurance from the National Health Insurance System, had an initial medical evaluation between 1997 and 2000 and were prospectively followed biennially. </sec> <sec id="st4"> <title>RESULTS</title> Participants with DM had a higher risk for incident TB (hazard ratio [HR] 1.81, 95%CI 1.71-1.91 in males, HR 1.33; 95%CI 1.20-1.47 in females) than those without DM. There was a strong positive trend for TB risk with rising FSG among males. The risk for recurrent TB among those with previous TB was significantly higher in males (HR 1.58, 95%CI 1.43-1.75) and in females with DM (HR 1.38, 95%CI 1.08-1.76). The increased risk of death from TB during follow-up was also significant in men (HR 1.91, 95%CI 1.87-1.95) and in women (HR 1.71, 95%CI 1.65-1.77). </sec> <sec id="st5"> <title>CONCLUSIONS</title> A diagnosis of DM is a risk factor for TB, TB recurrence and death from TB. Screening for TB should be considered among people living with DM in Korea, particularly those with severe DM. </sec>.

Respiratory health status is associated with treatment outcomes in pulmonary tuberculosis

<sec id="st1"> <title>BACKGROUND</title> The association between respiratory impairment and tuberculosis (TB) treatment outcomes is not clear. </sec> <sec id="st2"> <title>METHODS</title> We prospectively evaluated respiratory health status, measured using the Saint George's Respiratory Questionnaire (SGRQ), in a cohort of new adult pulmonary TB cases during and up to 18 months following treatment in India. Associations between total SGRQ scores and poor treatment outcomes of failure, recurrence and all-cause death were measured using multivariable Poisson regression. </sec> <sec id="st3"> <title>RESULTS</title> We enrolled 455 participants contributing 619 person-years at risk; 39 failed treatment, 23 had recurrence and 16 died. The median age was 38 years (interquartile range 26-49); 147 (32%) ever smoked. SGRQ scores at treatment initiation were predictive of death during treatment (14% higher risk per 4-point increase in baseline SGRQ scores, 95%CI 2-28, P = 0.01). Improvement in SGRQ scores during treatment was associated with a lower risk of failure (1% lower risk for every per cent improvement during treatment, 95%CI 1-2, P = 0.05). Clinically relevant worsening in SGRQ scores following successful treatment was associated with a higher risk of recurrence (15% higher risk per 4-point increase scores, 95%CI 4-27, P = 0.004). </sec> <sec id="st4"> <title>CONCLUSION</title> Impaired respiratory health status was associated with poor TB treatment outcomes. The SGRQ may be used to monitor treatment response and predict the risk of death in pulmonary TB. </sec>.

Cost-effectiveness of universal isoniazid preventive therapy among HIV-infected pregnant women in South Africa

OBJECTIVE

To estimate the incremental cost-effectiveness of universal vs. test-directed treatment of latent tuberculous infection (LTBI) among human immunodeficiency virus (HIV) positive pregnant women in South Africa.

METHODS

We compared tuberculin skin test (TST) directed isoniazid preventive therapy (IPT) (TST placement with delivery of IPT to women with positive results) against QuantiFERON^®-TB Gold In-Tube (QGIT) directed IPT and universal IPT using decision analysis. Costs were measured empirically in six primary care public health clinics in Matlosana, South Africa. The primary outcome was the incremental cost-effectiveness ratio, expressed in 2016 US$ per disability-adjusted life-year (DALY) averted.

RESULTS

We estimated that 29.2 of every 1000 pregnant women would develop TB over the course of 1 year in the absence of IPT. TST-directed IPT reduced this number to 24.5 vs. 22.6 with QGIT-directed IPT and 21.0 with universal IPT. Universal IPT was estimated to cost $640/DALY averted (95% uncertainty range $44-$3146) relative to TST-directed IPT and was less costly and more effective (i.e., dominant) than QGIT-directed IPT. Cost-effectiveness was most sensitive to the probability of developing TB and LTBI prevalence.

CONCLUSION

Providing IPT to all eligible women can be a cost-effective strategy to prevent TB among HIV-positive pregnant women in South Africa.

Trends in HbA1c levels and implications for diabetes screening in tuberculosis cases undergoing treatment in India

SETTING

The optimal timing of screening for diabetes mellitus (DM) among tuberculosis (TB) cases is unclear due to the possibility of stress hyperglycemia.

DESIGN

We evaluated adult (18 years) pulmonary TB cases at treatment initiation as well as at 3 months, 6 months and 12 months. DM was identified by self-report (known DM) or glycated hemoglobin (HbA1c)  6.5% (new DM). Trends in HbA1c levels during treatment were assessed using non-parametric tests.

RESULTS

Of the 392 participants enrolled, 75 (19%) had DM, 30 (40%) of whom had new DM. Of the 45 participants with known DM, respectively 37 (82%) and 40 (89%) received medication to lower glucose levels at treatment initiation and completion; one participant with new DM initiated glucose-lowering medication during follow-up. The median HbA1c level in participants with known, new and no DM was respectively 10.1% (interquartile range [IQR] 8.3-11.6), 8.5% (IQR 6.7-11.5) and 5.6% (IQR 5.3-5.9) at treatment initiation, and 8.7% (IQR 6.8-11.3), 7.1% (IQR 5.8-9.5) and 5.3% (IQR 5.1-5.6) at treatment completion (P < 0.001). Overall, 5 (12%) with known and 13 (43%) with new DM at treatment initiation had reverted to HbA1c < 6.5% by treatment completion (P = 0.003); the majority of reversions occurred during the first 3 months, with no significant reversions beyond 6 months.

CONCLUSION

HbA1c levels declined with anti-tuberculosis treatment. Repeat HbA1c testing at treatment completion could reduce the risk of misdiagnosis of DM.

Prevalence of dysglycemia and clinical presentation of pulmonary tuberculosis in Western India

SETTING

Pune, India.

OBJECTIVES

To estimate the prevalence and risk factors of pre-diabetes mellitus (DM) and DM, and its associations with the clinical presentation of tuberculosis (TB).

DESIGN

Screening for DM was conducted among adults (age  18 years) with confirmed TB between December 2013 and January 2017. We used multinomial regression to evaluate the risk factors for pre-DM (glycated hemoglobin [HbA1c]  5.7-6.5% or fasting glucose 100-125 mg/dl) and DM (HbA1c  6.5% or fasting glucose  126 mg/dl or random blood glucose > 200 mg/dl or self-reported DM history/treatment) and the association of dysglycemia with the severity of TB disease.

RESULTS

Among 1793 participants screened, 890 (50%) had microbiologically confirmed TB. Of these, 33% had pre-DM and 18% had DM; 41% were newly diagnosed. The median HbA1c level among newly diagnosed DM was 7.0% vs. 10.3% among known DM (P < 0.001). DM (adjusted OR [aOR] 4.94, 95%CI 2.33-10.48) and each per cent increase in HbA1c (aOR 1.42, 95%CI 1.01-2.01) was associated with >1+ smear grade or 9 days to TB detection.

CONCLUSION

Over half of newly diagnosed TB patients had DM or pre-DM. DM and increasing dysglycemia was associated with higher bacterial burden at TB diagnosis, potentially indicating a higher risk of TB transmission to close contacts.

A systematic review of the effectiveness of smoking cessation interventions among patients with tuberculosis

Smoking is a significant risk factor for morbidity and mortality, particularly among patients with tuberculosis (TB). Although smoking cessation is recommended by the World Health Organization and the International Union Against Tuberculosis and Lung Disease, there has been no published evaluation of smoking cessation interventions among people with TB. The purpose of this review was to synthesize the evidence on interventions and suggest practice, research and policy implications. A systematic review of the literature identified 14 peer-reviewed studies describing 13 smoking cessation interventions between 2007 and 2017. There were five randomized controlled trials, three non-randomized interventions, and five prospective cohort studies. The primary types of interventions were brief advice (n = 9), behavioral counseling (n = 4), medication (n = 3), and community-based care (n = 3). A variety of health care workers (HCWs) implemented interventions, from physicians, nurses, clinic staff, community health workers (CHWs), as did family members. There was significant heterogeneity of design, definition of smoking and smoking abstinence, and implementation, making comparison across studies difficult. Although all smoking interventions increased smoking cessation between 15% and 82%, many studies had a high risk for bias, including six without a control group. The implementing personnel did not make a large difference in cessation results, suggesting that national TB programs may customize according to their needs and limitations. Family members may be important supporters/advocates for cessation. Future research should standardize definitions of smoking and cessation to allow comparisons across studies. Policy makers should encourage collaboration between tobacco and TB initiatives and develop smoking cessation measures to maximize results in low-resource settings.

Applying the Care Group model to tuberculosis control: findings from a community-based project in Mozambique

BACKGROUND

We describe the effectiveness of an innovative community-based social mobilization approach called Care Groups to improve the effectiveness of the national tuberculosis (TB) program by increasing TB testing and improving treatment outcomes in six districts of rural Mozambique.

METHODS

The Care Group approach, which was implemented in a population of 218 191, enabled a facilitator to meet every 6 months with 10-12 community health volunteers (forming a Care Group) to share key TB messages and then for them to convey these messages over the subsequent 6 months to 10-12 households. Three household surveys were performed over 5 years to measure population-level changes in knowledge and behaviors. Data from village TB, laboratory, and district registers were also used to monitor activities and outcomes.

RESULTS

There were substantial improvements in TB-related knowledge and behaviors in the number of patients initiating treatment, in the percentage of patients receiving directly observed treatment, in treatment success, and in TB-related mortality.

CONCLUSION

Care Groups are uniquely suited to address some of the challenges of TB control. This project sheds light on a new strategy for engaging communities to address not only TB, but other health priorities as well.

Risk factors for transmission of tuberculosis among United States-born African Americans and Whites

SETTING

Tuberculosis (TB) patients and their contacts enrolled in nine states and the District of Columbia from 16 December 2009 to 31 March 2011.

OBJECTIVE

To evaluate characteristics of TB patients that are predictive of tuberculous infection in their close contacts.

DESIGN

The study population was enrolled from a list of eligible African-American and White TB patients from the TB registry at each site. Information about close contacts was abstracted from the standard reports of each site.

RESULTS

Close contacts of African-American TB patients had twice the risk of infection of contacts of White patients (adjusted risk ratio [aRR] 2.1, 95%CI 1.3-3.4). Close contacts of patients whose sputum was positive for acid-fast bacilli on sputum smear microscopy had 1.6 times the risk of tuberculous infection compared to contacts of smear-negative patients (95%CI 1.1-2.3). TB patients with longer (>3 months) estimated times to diagnosis did not have higher proportions of infected contacts (aRR 1.2, 95%CI 0.9-1.6).

CONCLUSION

African-American race and sputum smear positivity were predictive of tuberculous infection in close contacts. This study did not support previous findings that longer estimated time to diagnosis predicted tuberculous infection in contacts.

Directly observed therapy of tuberculosis in Brazil: associated determinants and impact on treatment outcome

SETTING

All Brazilian states.

OBJECTIVES

To assess the determinants of tuberculosis (TB) in patients undergoing directly observed therapy (DOT) and the impact of DOT on treatment outcomes.

DESIGN

This is a cross-sectional study among TB patients aged ⩾18 years conducted in 2011. The primary outcome was the status of DOT received, while the secondary was the outcome of anti-tuberculosis treatment.

RESULTS

In 2011, 35 775 (38.3%) subjects received DOT. The odds of receiving DOT were higher in patients with the following characteristics: brown/mestizo patients (OR 1.18, 95%CI 1.14-1.22) and those of other ethnic groups (OR 2.01, 95%CI 1.79-2.27) compared to Whites, alcohol users (OR 1.37, 95%CI 1.28-1.47) and those with mental disorders (OR 1.88, 95%CI 1.54-2.29). The odds of receiving DOT were lower in human immunodeficiency virus positive patients (OR 0.64, 95%CI 0.60-0.68). Patients who did not receive DOT were more likely to default from anti-tuberculosis treatment (OR 0.62, 95%CI 0.57-0.66), die due to TB (OR 0.68, 95%CI 0.61-0.77) and to have unknown treatment outcomes (OR 0.71, 95%CI 0.66-0.76). The adjusted preventable fraction of DOT in the reduction of unfavorable outcomes was 25%.

CONCLUSION

Sociodemographic and clinical characteristics are determinants of anti-tuberculosis treatment outcomes in patients undergoing DOT; DOT use led to a 25% reduction in unfavorable outcomes.

Cost-effectiveness of tuberculosis screening and isoniazid treatment in the TB/HIV in Rio (THRio) Study

OBJECTIVE

To estimate the incremental cost-effectiveness of tuberculosis (TB) screening and isoniazid preventive therapy (IPT) among human immunodeficiency virus (HIV) infected adults in Rio de Janeiro, Brazil.

DESIGN

We used decision analysis, populated by data from a cluster-randomized trial, to project the costs (in 2010 USD) and effectiveness (in disability-adjusted life years [DALYs] averted) of training health care workers to implement the tuberculin skin test (TST), followed by IPT for TST-positive patients with no evidence of active TB. This intervention was compared to a baseline of usual care. We used time horizons of 1 year for the intervention and 20 years for disease outcomes, with all future DALYs and medical costs discounted at 3% per year.

RESULTS

Providing this intervention to 100 people would avert 1.14 discounted DALYs (1.57 undiscounted DALYs). The median estimated incremental cost-effectiveness ratio was $2273 (IQR $1779-$3135) per DALY averted, less than Brazil's 2010 per capita gross domestic product (GDP) of $11,700. Results were most sensitive to the cost of providing the training.

CONCLUSION

Training health care workers to screen HIV-infected adults with TST and provide IPT to those with latent tuberculous infection can be considered cost-effective relative to the Brazilian GDP per capita.

Tuberculosis control in a socially vulnerable area: a community intervention beyond DOT in a Brazilian favela

OBJECTIVES

To evaluate the population-based impact of a comprehensive intervention to strengthen tuberculosis (TB) control in Rocinha, the largest urban slum in Rio de Janeiro, Brazil.

DESIGN

In July 2003, 40 lay persons were hired and trained as community health workers to supervise treatment, implement educational activities and establish a supportive social network for anti-tuberculosis treatment. Between July 2005 and June 2008, a door-to-door active case finding campaign was conducted. Data were obtained from the Brazilian National Reporting System, which collects information from the TB notification form for every reported case.

RESULTS

Between January 2001 and December 2008, 2623 TB cases were reported, 852 before and 1771 after the start of the program. Following the intervention, treatment success rates increased (67.6% vs. 83.2%, P < 0.001) and default rates dropped (17.8% vs. 5.5%, P < 0.001). Compared to the pre-intervention period, the TB case rate declined by an average of 39 cases per 100,000 population per 6 months (P = 0.003) in the post-intervention period, although this may have been due to secular trends already in place at the start of the intervention. Case rates declined from 591/100,000 in 2001 to 496/100,000 in 2008.

CONCLUSION

With proper planning and effective community involvement, a successful intervention can lead to high cure rates and may contribute to a decrease in TB notification rates.

Screening for active tuberculosis: methodological challenges in implementation and evaluation

As active screening strategies for tuberculosis (TB) continue to rise globally, it has become increasingly important to consider the methodological challenges in designing and implementing these strategies. The key challenges associated with TB screening can be summarized in terms of four continua or spectra, namely those of 1) TB disease and diagnostic yield, 2) TB risk and resource availability, 3) TB screening strategies, and 4) outcomes and impact measurements of screening programs. In this review, we provide a discussion of these challenges to help guide development of TB screening strategies that will be effective in a given epidemiological setting.

Safety and effectiveness of HAART in tuberculosis-HIV co-infected patients in Brazil

BACKGROUND

Antiretroviral therapy (ART) significantly reduces tuberculosis (TB) incidence among persons with human immunodeficiency virus (HIV), but the safety and effectiveness of concomitant treatment for both diseases remain unclear.

OBJECTIVE

To evaluate the impact of ART and anti-tuberculosis treatment on survival and risk of adverse events (AE) among co-infected individuals.

METHODS

In a retrospective cohort study, clinical data were collected from 618 TB-HIV patients treated with rifampin, isoniazid and pyrazinamide ± ethambutol between 1 January 1995 and 31 December 2003. Patients were categorized into two groups: highly active ART (HAART) or no ART. Different HAART regimens were evaluated. Bivariate analysis, multivariate logistic regression and survival analysis using Cox proportional hazards regression were used.

RESULTS

One-year mortality was lower for patients receiving HAART (adjusted hazard ratio [aHR] 0.17, 95%CI 0.09-0.31) compared to no ART. HAART increased the risk of AE (aHR 2.08, 95%CI 1.29-3.36). The odds of AE when receiving a ritonavir + saquinavir HAART regimen was eight-fold higher compared to no ART (OR 8.31, 95%CI 3.04-22.69), while efavirenz-based HAART was not associated with a significantly increased risk of AE (OR 1.42, 95%CI 0.76-2.65).

CONCLUSION

HIV patients with TB have significantly better survival if they receive HAART during anti-tuberculosis treatment. Efavirenz-based HAART is associated with fewer AEs than protease inhibitor-based HAART.

Quality of life among people treated for tuberculosis and human immunodeficiency virus in Rio de Janeiro, Brazil

We measured quality of life (QOL) among individuals receiving treatment for human immunodeficiency virus (HIV; n = 45), active tuberculosis (TB; n = 44) and both TB and HIV (n = 9) in Rio de Janeiro, Brazil. Active treated TB was associated with lower physical health (absolute decrease of 0.95 standard deviation in summary score), but not mental health, among people being treated for HIV. Visual analogue scale scores were similar across all three populations, and corresponded closely to standard disability weights used in the literature. Among patients receiving treatment, those with HIV, active TB and both conditions together appear to have similar QOL.

Predictors of delayed culture conversion in patients treated for multidrug-resistant tuberculosis in Pakistan

Culture conversion is an interim monitoring tool for treatment of multidrug-resistant tuberculosis (MDR-TB). We evaluated the time to and predictors of culture conversion in pulmonary MDR-TB patients enrolled in the community-based MDR-TB management program at the Indus Hospital in Karachi, Pakistan. Despite strict daily directly observed therapy, monthly food incentives and patient counseling, the median time to culture conversion was 196 days (range 32-471). The cumulative probabilities of culture conversion by 2, 4, 6 and 12 months were respectively 6%, 33%, 47%, and 73%. Smoking, high smear grade at baseline and previous use of second-line drugs delayed culture conversion.

Intention to quit smoking among human immunodeficiency virus infected adults in Johannesburg, South Africa

Although smoking is common in human immunodeficiency virus (HIV) infected individuals, in resource-constrained, high HIV prevalence settings, information on smoking cessation intent and acceptability is limited. Of 150 self-reported current smokers surveyed in two South African HIV clinics, 62 (42%) reported intent to quit smoking in the next year, while 86 (58%) were not interested in quitting or had no plan to quit; 132 (82%) had attempted to quit at least once in the past. Respondents' preferred cessation strategies were counseling and nicotine replacement. A high proportion of HIV-infected smokers want to quit, and interventions should be provided as part of HIV care.

Delay in diagnosis of pulmonary tuberculosis at a primary health clinic in Vitoria, Brazil

SETTING

Primary health clinics in Vitoria, Espirito Santo, Brazil.

OBJECTIVE

To identify risk factors associated with patient and health care delays among patients seeking care at primary health clinics.

METHODS

A prospective study among tuberculosis (TB) patients diagnosed in Vitoria between 1 January 2003 and 30 December 2007. A questionnaire ascertained the date of onset and duration of TB symptoms and medical records were reviewed. Between-group distributions of delay were compared and multivariate logistic regression was performed.

RESULTS

Of 304 patients, 296 (97%) reported at least one TB symptom presenting for the first time to a qualified health service; 244 (80%) reported cough > 3 weeks. Median health care delay was 30 days (range 5-68), and median total delay was 110 days (range 26-784). Multivariate analysis revealed any cough (OR(adj) 7.35, 95%CI 2.40-22.5) and weight at TB diagnosis < 60 kg (OR(adj) 5.92, 95%CI 1.83-19.1) to be associated with patient delay of ≥ 30 days. Factors increasing risk of prolonged delay (≥ 90 days) were age ≥ 30 years (OR(adj) 1.93, 95%CI 1.09-3.43) and chest pain (OR(adj) 2.42, 95%CI 1.29-4.53).

CONCLUSION

Improving health care workers' education regarding TB symptoms and implementing active case finding in targeted populations may reduce delays.

Spatial patterns of pulmonary tuberculosis incidence and their relationship to socio-economic status in Vitoria, Brazil

OBJECTIVE

To investigate spatial patterns of the incidence of pulmonary tuberculosis (TB) and its relationship with socio-economic status in Vitoria, Espirito Santo, Brazil.

DESIGN

In a 4-year, retrospective, territory-based surveillance study of all new pulmonary TB cases conducted in Vitoria between 2002 and 2006, spatial patterns of disease incidence were compared using spatial clustering statistics (Anselin's local indicators of spatial association [LISA] and Getis-Ord Gi* statistics), smoothed empirical Bayes estimates and model-predicted incidence rates. Spatial Poisson models were fit to examine the relationship between socio-economic status and TB incidence.

RESULTS

A total of 651 TB cases were reported across 78 neighborhoods, with rates ranging from 0 to 129 cases per 100,000 population. Moran's I indicated strong spatial autocorrelation among incidence rates (0.399, P < 0.0001), and four areas of high incidence were identified by LISA and Gi* statistics. Smoothed spatial empirical Bayes estimates demonstrate that two of these areas range from 70 to 90 cases/100,000, while the other two range from 40 to 70 cases/100,000. TB incidence and socio-economic status had a significant curvilinear relationship (P = 0.02).

CONCLUSIONS

Data derived from these spatial statistical tools will help TB control programs to allocate TB resources to those populations most at risk of increasing TB rates and to target areas where TB control efforts need to be concentrated.

Controlled trial of active tuberculosis case finding in a Brazilian favela

SETTING

A large, impoverished squatters' settlement (favela), Rio de Janeiro, Brazil.

OBJECTIVE

To assess the community impact of active case finding for tuberculosis (TB) compared to an enhanced case-finding strategy.

DESIGN

A pair-matched, cluster-randomized trial comparing household symptom screening and spot sputum collection (Arm 1) vs. distribution of an educational pamphlet (Arm 2) was performed in a large Brazilian favela. We compared TB case-notification rates, time from symptom onset to treatment start and treatment completion proportions between arms. Fourteen neighborhoods (estimated population 58,587) were pair-matched by prior TB case rates and randomly allocated to one of two interventions. TB was diagnosed using acid-fast bacilli smears. New TB cases were interviewed and clinic records were reviewed.

RESULTS

A total of 193 TB cases were identified in the 14 study neighborhoods (incidence proportion 329 per 100,000 population). The case identification rate in Arm 1 was 934/100,000 person-years (py) vs. 604/100,000 py in Arm 2 (RR 1.55, 95%CI 1.10-1.99). No significant differences were found in time from cough onset to treatment start or proportion completing treatment.

CONCLUSIONS

A door-to-door case-finding campaign was more effective (while ongoing) at detecting prevalent cases and influencing people to come for care than leafleting, but no differences were seen in time to treatment start or treatment completion.

Community-randomized trial of enhanced DOTS for tuberculosis control in Rio de Janeiro, Brazil

SETTING

Central Rio de Janeiro, Brazil.

OBJECTIVE

To compare the impact of routine DOTS vs. enhanced DOTS (DOTS-Ampliado or DOTS-A) on tuberculosis (TB) incidence.

DESIGN

Cluster-randomized trial in eight urban neighborhoods pair-matched by TB incidence and randomly assigned to receive either the DOTS-A or DOTS strategy. DOTS-A added intensive screening of household contacts of active TB cases and provision of treatment to secondary cases and preventive therapy to contacts with latent TB infection (LTBI) to the standard DOTS strategy. The primary endpoint was the TB incidence rates in communities after 5 years of intervention.

RESULTS

From November 2000 to December 2004, respectively 339 and 311 pulmonary TB cases were enrolled and 1003 and 960 household were identified in DOTS and DOTS-A communities. Among contacts from DOTS-A communities, 26 (4%) had active TB diagnosed and treated, 429 (61.3%) had LTBI detected and 258 (60.1%) started preventive therapy. TB incidence increased by 5% in DOTS communities and decreased by 10% in DOTS-A communities, for a difference of 15% after 5 years (P = 0.04).

CONCLUSION

DOTS-A was associated with a modest reduction in TB incidence and may be an important strategy for reducing the burden of TB.

Tuberculosis incidence among contacts of active pulmonary tuberculosis

BACKGROUND

Treatment of latent tuberculosis (TB) infection (LTBI) in Brazil is recommended only in the case of contacts of pulmonary smear-positive TB patients aged<or=15 years with a tuberculin skin test (TST)>or=10 mm and no previous bacille Calmette-Guérin (BCG) vaccination or with a TST>or=15 mm regardless of previous BCG vaccination.

OBJECTIVE

To evaluate the 2-year incidence and predictors of TB among contacts who did not meet the Brazilian criteria for LTBI treatment.

DESIGN

Retrospective cohort study. Contacts aged between 12 and 15 years and those aged>or=15 years who did not meet the Brazilian criteria for LTBI treatment were enrolled in the study.

RESULTS

TB incidence was 3.2% (22/667), with an estimated TB rate of 1649 per 100000 population. Risk of TB was greater among the 349 contacts with TST>or=5 mm (5.4%) compared to the 318 contacts with TST<5 mm (0.9%; RR 6.04, 95%CI 1.7-20.6).

CONCLUSION

The high incidence of TB among contacts who did not meet the Brazilian criteria for LTBI treatment strongly suggests that these criteria should be reviewed. Furthermore, even among BCG-vaccinated contacts, TST induration>or=5 mm was the only variable that predicted the development of TB disease within 2years.

Tuberculosis as primary cause of death among AIDS cases in Rio de Janeiro, Brazil

SETTING

Data from the mortality database, Rio de Janeiro City (RJC) Health Department, Rio de Janeiro, Brazil.

OBJECTIVES

To determine the role played by tuberculosis (TB) in Brazil's human immunodeficiency virus (HIV) positive population, we investigated the frequency of TB as the primary cause of death among HIV-positive subjects in RJC.

DESIGN

Information about acquired immune-deficiency syndrome (AIDS) deaths from 1996 to 2005 in individuals aged >12 years was obtained from the Mortality Information System (SIM), and the cause of death was classified according to the International Classification of Diseases (ICD-10), through primary causes coded in Chapter I--B20 to B24 (HIV disease).

RESULTS

There were 8601 AIDS-related deaths in RJC between 1996 and 2005. TB was the primary cause of death in 9.0% of all AIDS-related deaths, while Pneumocystis carinii pneumonia (PCP) accounted for 4.7%. TB cases erroneously classified under other infectious diseases may have contributed to an underestimation of the number of TB deaths among HIV-positive patients.

CONCLUSION

Our study showed that TB is the leading cause of AIDS-related deaths and is responsible for twice as many deaths as PCP, in a scenario of free access to antiretrovirals. The potential benefits of TB preventive treatment and of the availability of highly active antiretroviral treatment could not be established by this analysis.

Trend and seasonality of tuberculosis in Spain, 1996-2004

This study aimed to analyse the trend and seasonality of tuberculosis (TB) in Spain over the past decade. Weekly TB incidence was calculated using data from the National Surveillance Network for the period 1996-2004. Secular trends and seasonal components were estimated using time-series analysis (least-squares method and Fourier transformation). A decline in incidence was observed, from 23.4 cases per 100,000 population in 1997 to 15.1 in 2004, and an annual cycle peaking in June was detected. Time-series analyses are necessary for detecting changes in the epidemiological pattern of TB in Spain, and it should be the first step towards the development of a predictive model.

Recurrent tuberculosis and its risk factors: adequately treated patients are still at high risk

Recurrent tuberculosis (TB) poses significant threats, including drug resistance, to TB control programs. However, recurrence and its causes, particularly in the era of epidemic human immunodeficiency virus (HIV), have not been well described. We systematically searched published material for studies reporting on recurrent TB following completion of standard treatment regimens to provide data on the issue. A total of 32 studies were reviewed. Among controlled trials, the overall recurrence rates (per 100,000 person-years) were respectively 3,010 (95%CI 2,230-3,970) and 2,290 (95%CI 1,730-2,940) at 6 and 12 months after treatment completion. Recurrence rates were higher among observational studies compared to controlled trials and in countries with high versus low background TB incidence. TB recurrence (%) was higher among HIV-infected (6.7, 95%CI 5.9-7.6) than non-HIV-infected individuals (3.3, 95%CI 2.8-3.9). Factors independently associated with recurrence in the literature included residual cavitation, greater area of involved lung tissue, positive sputum culture at 2 months of treatment and HIV infection. Among those with HIV infection, recurrent TB was associated with a low initial CD(4) count and receiving less than 37 weeks of anti-tuberculosis treatment. We argue that adequately treated patients are still at high risk for recurrent disease and should be considered in case-finding strategies. Moreover, those with multiple risk factors may benefit from modification of standard treatment.

Prevalence of pulmonary tuberculosis among respiratory symptomatic subjects in an out-patient primary health unit

SETTING

Out-patient primary health unit (OPHU) in Rio de Janeiro City, Brazil.

OBJECTIVE

To evaluate the impact on the detection of tuberculosis (TB) cases of reducing the time of respiratory symptoms from 'cough > or = 3 weeks' to 'cough > or = 1 week' as a criteria for TB case finding among individuals visiting an OPHU for any other reason.

DESIGN

Cross-sectional study.

RESULTS

During the period of the study, 10.7% (765/ 7174) of subjects reported cough > or = 1 week. Among 542 subjects enrolled in the study with cough > or = 1 week, 15 (2.7%) cases were diagnosed with pulmonary tuberculosis (PTB, 2767/100000). The probability of detecting TB in the OPHU setting among subjects seeking care for respiratory symptoms was significantly higher than among those presenting to the OPHU for other reasons (OR 31.5, 95% CI 4.1-241.9; P < 0.0001). The probability of identifying TB among patients seeking care due to respiratory symptoms was not influenced by the duration of cough (P = 0.7).

CONCLUSION

These findings suggest that the screening criteria for TB case finding of cough for less than the usual 3 weeks among patients who attend a health facility due to respiratory symptoms in settings with a high prevalence of TB may significantly improve the proportion of TB cases diagnosed.

Delayed tuberculosis diagnosis and tuberculosis transmission

SETTING

Tuberculosis (TB) patients and their close contacts reported to the Maryland Department of Health and Mental Hygiene from 1 June 2000 to 30 November 2001.

OBJECTIVES

A recent prospective study found that 49% of pulmonary TB patients had total treatment delays > or = 90 days. This cohort was analyzed to determine the association between total treatment delay and TB transmission.

DESIGN

TB patient data were collected as part of a prospective cohort study; contact data were collected from local health departments.

RESULTS

Close contacts of 54 US-born patients (n = 310) and those of 70 foreign-born cases (n = 393) received tuberculin skin tests (TSTs). Among contacts of US-born patients with a total treatment delay of > or = 90 days, 40% had positive TSTs vs. 24% contacts of patients with shorter delays (aOR 2.34; P = 0.03). Other patient factors associated with TST positivity among contacts of US-born cases were black race (aOR 3.03; P = 0.05), sputum smear positive for AFB (aOR 3.29; P = 0.01) and chest radiograph with cavitation (aOR 3.11; P = 0.01). No associations were observed between foreign-born patients and risk of TST positivity among their contacts.

CONCLUSION

Among US-born patients, delay in TB diagnosis is associated with greater transmission of infection to contacts and could be used independently of other index patient factors to identify contacts at greatest risk of TB infection.

Active case finding of tuberculosis: historical perspective and future prospects

Despite a history of remarkable scientific achievements in microbiology and therapeutics, tuberculosis (TB) continues to pose an extraordinary threat to human health. Case finding and treatment of TB disease are the principal means of controlling transmission and reducing incidence. This review presents a historical perspective of active case finding (ACF) of TB, detailing case detection strategies that have been used over the last century. This review is divided into the following sections: mass radiography, house-to-house surveys, out-patient case detection, enhanced case finding, high-risk populations and cost-effectiveness. The report concludes with a discussion and recommendations for future case finding strategies. Understanding the strengths and weaknesses of these methods will help inform and shape ACF as a TB control policy in the twenty-first century.

Patient and health care system delays in pulmonary tuberculosis diagnosis in a low-incidence state

SETTING

Tuberculosis (TB) patients reported to the Maryland Department of Health and Mental Hygiene from 1 June 2000 to 30 November 2001.

OBJECTIVE

To determine the extent of delayed diagnosis of TB and to assess patient and provider factors associated with delays.

DESIGN

A prospective cohort study.

RESULTS

Median patient, health care and total delays were 32, 26 and 89 days, respectively, for 158 patients. Non-white (relative hazard [RH] 0.62; 95% CI 0.39-0.98) and less educated (RH 0.43; 95% CI 0.26-0.72) patients had longer patient delays. English-speaking patients (RH 0.40; 95% CI 0.24-0.68) had increased health care delays, as did patients who received a diagnosis of a respiratory illness and non-TB antibiotics (RH 0.69; 95% CI 0.49-0.96) prior to a TB diagnosis. Patients first presenting to a private physician (51 days) rather than a hospital emergency room (18 days; RH 1.87; 95% CI 1.05-3.33) or public health clinic (10 days; RH 1.79; 95% CI 1.21-2.63) had longer health care delays. When a TB diagnostic tool (chest radiograph or AFB culture) was utilized, a more rapid diagnosis of TB was made.

CONCLUSION

Education of the patient population about TB symptoms might reduce delays. Increased physician awareness of the current epidemiology of TB and better use of available diagnostic tools will reduce delays and may reduce TB transmission.

Impact of empiric antibiotics and chest radiograph on delays in the diagnosis of tuberculosis

SETTING

Maryland Department of Health and Mental Hygiene, Division of Tuberculosis (TB) Control.

OBJECTIVES

To assess the implications of antibiotic treatment of presumed community-acquired pneumonia (CAP) on delays in the diagnosis of TB, and to assess the frequency with which chest radiographs (CXRs) were utilized before a diagnosis of pneumonia or pulmonary TB was made.

DESIGN

A nested case-control study within a prospective study conducted to assess factors associated with delays in the diagnosis of TB.

RESULTS

Cases (n = 85; 54%) were patients who received antibiotics for non-TB diagnoses/indications prior to TB diagnosis, and controls (n = 73; 46%) were patients who had initially received TB therapy. Median health care delay for cases was 39 days vs. 15 days (P < 0.01) for controls. Median antibiotic delay was similar among all antibiotic classes. Of 54 patients who did not have a CXR at their first health care visit, 41 (79%) received empiric antibiotics, compared to 44/105 (42%) who had a CXR (P < 0.01). Only 31/54 (57%) patients initially diagnosed with CAP had a CXR at the time of diagnosis.

CONCLUSION

More widespread use of CXR when diagnosing CAP should reduce delays in diagnosing TB, and the unnecessary use of antibiotics.

Evaluation of an extensive tuberculosis contact investigation in an urban community and jail

SETTING

Urban community and jail.

OBJECTIVES/DESIGN

Evaluate outcome and process of an extensive tuberculosis contact investigation, including completion of treatment of latent TB infection (TLTBI).

RESULTS

Between April 2000 and September 2001, 18 epidemiologically-linked tuberculosis cases were identified; 15 were culture-confirmed, all with a matching 14-band DNA fingerprint pattern. The source case had cavitary pulmonary disease and had been incarcerated 4 months prior to diagnosis. Sixty-six of 67 (99%) community contacts and 221/344 (64%) jail contacts were evaluated. The presumed new infection rate was 56% for community contacts (11 cases, 25 tuberculin skin test [TST] positive) and 20% for jail contacts (6 cases, 32 TST converters). Screening results for 113 (33%) jail contacts were obtained in the jail TST registry upon rearrest. All identified cases completed treatment. Of 22 community contacts initiating TLTBI, 11 completed (44% of infected, 50% of initiators). Of 32 infected jail contacts, 12 initiated TLTBI (all who remained incarcerated), and 10 completed (31% of infected, 83% of initiators). None of 20 additional in-fected jail contacts, all of whose TST conversions were identified with re-arrest data, were subsequently located. Two additional related cases have been identified as of October 2003.

CONCLUSIONS

Close health department/corrections collaboration facilitated this extensive contact investigation, which identified high Mycobacterium tuberculosis transmission rates and controlled the outbreak. Numerous contacts were identified and screened, but rates of treatment completion for infected contacts were low. Novel strategies are needed to maximize the number of infected contacts who are not only identified and evaluated, but completely treated.

Transmission of Mycobacterium tuberculosis through casual contact with an infectious case

BACKGROUND

An ongoing restriction fragment length polymorphism study of Mycobacterium tuberculosis isolates from tuberculosis cases showed an identical 12-band IS6110 pattern unique to 3 unrelated patients (Patients A-C) diagnosed as having tuberculosis within a 9-month period.

METHODS

In an attempt to identify epidemiologic links between the 3 patients, we performed site visits to the retail business work site of patient A and conducted detailed interviews with all 3 patients and their contacts.

RESULTS

Patient B had visited patient A's work site 3 times during patient A's infectious period, spending no more than 15 minutes each time. Patient C visited patient A's work site on 6 to 10 occasions during this period for no more than 45 minutes at any one time. There were no other epidemiologic links between these 3 cases other than the contact at the store. Contact investigation identified 4 tuberculin skin test conversions among 8 (50%) of patient A's coworkers, 6 positive tests among 15 household contacts (40%), and 8 positive tests among 16 identified customers who were casual contacts (50%). Patient B and patient C were most likely infected by patient A during one of their brief visits to patient A's work site.

CONCLUSIONS

These data demonstrate that some tuberculosis is spread through casual contact not normally pursued in traditional contact investigations and that, in certain situations, M tuberculosis can be transmitted despite minimal duration of exposure. In addition, this outbreak emphasizes the importance of DNA fingerprinting data for identifying unusual transmission in unexpected settings.

Epidemiologic usefulness of spoligotyping for secondary typing of Mycobacterium tuberculosis isolates with low copy numbers of IS6110

Restriction fragment length polymorphism (RFLP) analysis of IS6110 is commonly used to DNA fingerprint Mycobacterium tuberculosis. However, low-copy (< or =5) IS6110 M. tuberculosis strains are poorly differentiated, requiring secondary typing. When spoligotyping was used as the secondary method, only 13% of Maryland culture-positive tuberculosis (TB) patients with low-copy IS6110-spoligotyped clustered strains had epidemiologic linkages to another patient, compared to 48% of those with high-copy strains clustered by IS6110 alone (P < 0.01). Spoligotyping did not improve a population-based molecular epidemiologic study of recent TB transmission.

Pfiesteria in Maryland: preliminary epidemiologic findings

In the fall of 1996, fish kills in Maryland rivers were attributed to the dinoflagellate, Pfiesteria piscicida. After a group of researchers established a potential link between exposure to Pfiesteria and an illness causing memory problems, state health authorities closed a portion of the Pocomoke River. To determine the extent of illness, the range of symptoms, potential risk factors for disease, and to provide information to concerned citizens, a toll-free hotline was created. All symptomatic persons who called the toll-free number were administered a standardized questionnaire. Persons who had been exposed to Pfiesteria or Pfiesteria-laden waters were more likely to have respiratory, neurologic, dermatologic, and gastrointestinal problems than those persons without exposure. Among the persons calling the hotline, many had extensive neuropsychologic testing. Of the neuropsychologic test battery, low scores on the Rey Auditory Verbal Learning Test (RAVLT), a standardized measure of learning and memory, best characterized illness related to Pfiesteria exposure. Patients with low RAVLT scores were more likely to have neurologic symptoms and skin lesions than control subjects. Low RAVLT scores were associated with fishing (OR, 9.00, 95% CI, 106, 409.87), catching fish with lesions (OR, 6.17, 95% CI 1.27, 32.10), and handling fish with lesions (OR, 5.34, 95% CI, 1.05, 29.92), but not with consumption of seafood. While preliminary, these results do suggest that some risk factors for Pfiesteria-related illness may be easy to modify and used to prevent unnecessary human exposure.

New approaches to reduce Staphylococcus aureus nosocomial infection rates: treating S. aureus nasal carriage

BACKGROUND

Nosocomial infections cause significant patient morbidity and mortality. The 2.5 million nosocomial infections that occur each year cost the US healthcare system $5 million to $10 million. Staphylococcus aureus has long been recognized as an important pathogen in human disease and is the most common cause of nosocomial infections.

OBJECTIVE

To describe the epidemiology of S. aureus nosocomial infections that are attributable to patients' endogenous colonization.

DATA SOURCES

Review of the English-language literature and a MEDLINE search (as of September 1997).

DATA SYNTHESIS

The ecologic niche of S. aureus is the anterior nares. The prevalence of S. aureus nasal carriage is approximately 20-25%, but varies among different populations, and is influenced by age, underlying illness, race, certain behaviors, and the environment in which the person lives or works. The link between S. aureus nasal carriage and development of subsequent S. aureus infections has been established in patients on hemodialysis, on continuous ambulatory peritoneal dialysis, and those undergoing surgery. S. aureus nasal carriers have a two-to tenfold increased risk of developing S. aureus surgical site or intravenous catheter infections. Thirty percent of 100% of S. aureus infections are due to endogenous flora and infecting strains were genetically identical to nasal strains. Three treatment strategies may eliminate nasal carriage: locally applied antibiotics or disinfectants, systemic antibiotics, and bacterial interference. Among these strategies, locally applied or systemic antibiotics are most commonly used. Nasal ointments or sprays and oral antibiotics have variable efficacy and their use frequently results in antimicrobial resistance among S. aureus strains. Of the commonly used agents, mupirocin (pseudomonic acid) ointment has been shown to be 97% effective in reducing S. aureus nasal carriage. However, resistance occurs when the ointment has been applied for a prolonged period over large surface areas.

CONCLUSIONS

Given the importance of S. aureus nosocomial infections and the increased risk of S. aureus nasal carriage in patients with nosocomial infections, investigators need to study cost-effective strategies to prevent certain types of nosocomial infections or nosocomial infections that occur in specific settings. One potential strategy is to decrease S. aureus nasal carriage among certain patient populations.