Community-based targeted case finding for tuberculosis and HIV in household contacts of patients with tuberculosis in South Africa

RATIONALE

South Africa has a high prevalence of tuberculosis (TB) and HIV-coinfected adults in whom TB is often diagnosed late in the course of disease.

OBJECTIVES

Improved case-finding approaches for TB and HIV are needed to reduce mortality and prevent transmission.

METHODS

We identified newly diagnosed index TB cases in a rural district and enrolled their households in a TB-HIV contact-tracing study. A group of randomly selected control households were enrolled to determine community prevalence of undetected TB and HIV. Field teams screened participants for TB symptoms, collected sputum specimens for smear microscopy and culture, provided HIV counseling and testing, and collected blood for CD4 testing. Participants were referred to public clinics for TB treatment and antiretroviral therapy.

MEASUREMENTS AND MAIN RESULTS

We evaluated 2,843 household contacts of 727 index patients with TB and 983 randomly selected control household members. The prevalence of TB in household contacts was 6,075 per 100,000 (95% confidence interval, 5,789-6,360 per 100,000), whereas the prevalence detected in randomly selected households was 407 per 100,000 (95% confidence interval, 0-912 per 100,000; prevalence difference, 5,668 per 100,000; P < 0.001). TB detected among contacts was less likely to be smear-positive than in the index patients (6% vs. 22%; P < 0.001). Most contacts with culture-confirmed TB were asymptomatic. At least one case of undiagnosed TB was found in 141 (19%) of 727 contact versus 4 (1%) of 312 control households. HIV testing was positive in 166 (11%) of 1,568 contacts tested versus 76 (14%) of 521 control participants tested (odds ratio, 1.48; P = 0.02).

CONCLUSIONS

Active case finding in TB contact households should be considered to improve TB and HIV case detection in high-prevalence settings, but sensitive diagnostic tools are necessary.

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.

Epidemiological profile of adult patients with tuberculosis and AIDS in the state of Espírito Santo, Brazil: cross-referencing tuberculosis and AIDS databases

OBJECTIVE

To evaluate the epidemiological profile of patients with tuberculosis (TB) only and that of patients with TB/AIDS in the state of Espírito Santo, Brazil, between 2000 and 2006.

METHODS

For the patients of interest, we collected demographic and clinical data from the Epidemiological Surveillance Center (TB database), Brazilian Case Registry Database, and Brazilian National Mortality Database, as well as the Brazilian National CD4+/CD8+ T Lymphocyte Count and Viral Load Network Laboratory Test Control System and the Logistic Medication Monitoring System (HIV/AIDS databases). All of the compiled data were cross-referenced.

RESULTS

During the study period, we identified 9,543 TB patients > 15 years of age, 437 of whom (4.6%) had AIDS. The median age did not differ between TB/AIDS and TB-only patients (35 years vs. 38 years). Of the 437 TB/AIDS patients, 298 (68.2%) were male, and 156 (35.8%) were in the 30-39 age bracket. In terms of TB treatment outcome, 79.0% were cured, 9.7% were referred to other facilities, 6.0% died, 5.2% abandoned treatment, and 0.2% developed multidrug-resistant TB. Death was 4.75 times more common in patients with TB/AIDS than in those with TB only. Pulmonary TB accounted for 82.4% of the cases. The combination of pulmonary and extrapulmonary TB was 8.2 times more common in the TB/AIDS patients than in the TB-only patients (95% CI: 6.2-10.8).

CONCLUSIONS

Our results emphasize the significance of AIDS among TB patients in Brazil, as well as the importance of evaluating secondary data in order to improve their quality and develop public health interventions.

Cost-effectiveness of community health worker versus home-based guardians for directly observed treatment of tuberculosis in Vitória, Espírito Santo State, Brazil

The objective of this study was to compare the costs and outcomes associated with guardian-supervised directly observed treatment relative to the standard of care Directly Observed Therapy, Short Course (DOTS) provided by community health workers (CHW). New cases of culture-positive pulmonary tuberculosis (TB) treated in Vitória, Espírito Santo State, Brazil, between January 2005 and December 2006 were interviewed and chose their preferred treatment strategy. Costs incurred by providers and patients (and patients' families) were estimated, and cost-effectiveness was assessed by comparing costs per successfully treated patient. 130 patients were included in the study; 84 chose CHW-supervised DOTS and 46 chose guardian-supervised DOTS. 45 of 46 (98%) patients treated with guardian-supervised DOTS were cured or completed treatment compared to 70/84 (83%) of the CHW-supervised patients (p = 0.01). Logistic regression showed only the strategy of supervision to be a significant association with treatment outcome, with guardian-supervised care strongly protective. Cost per patient treated with guardian-supervised DOTS was US$398, compared to US$548 for CHW-supervised DOTS. The guardian-supervised DOTS is an attractive option to complement CHW-supervised DOTS.

Physician adherence to guidelines for tuberculosis and HIV care in Rio de Janeiro, Brazil

BACKGROUND

Tuberculosis is the most common opportunistic infection among HIV-infected patients in Brazil. Brazil's national policy for HIV care recommends screening for latent tuberculosis (TB) and implementing isoniazid preventive therapy (IPT).

OBJECTIVES

We compared physician adherence to TB screening and other prevention and care policies among HIV primary care clinics in Rio de Janeiro City.

METHODS

Data on performance of CD4 counts, viral load testing, tuberculin skin testing (TST) and IPT were abstracted from patient charts at 29 HIV clinics in Rio de Janeiro as part of the TB/HIV in Rio (THRio) study. Data on use of pneumocystis jiroveci pneumonia (PCP) prophylaxis were also abstracted from a convenience sample of 150 patient charts at 10 HIV clinics. Comparisons were made between rates of adherence to TB guidelines and other HIV care guidelines.

RESULTS

Among the subset of 150 patients with confirmed HIV infection in 2003, 96% had at least one reported CD4 counts result; 93% had at least one viral load result reported; and, PCP prophylaxis was prescribed for 97% of patients with CD4 counts < 200 cells/mm³ or when clinically indicated. In contrast, 67 patients (45%) had a TST performed (all eligible); and only 11% (17) of eligible patients started IPT. Among 12,027 THRio cohort participants between 2003 and 2005, the mean number of CD4 counts and viral load counts was 2.5 and 1.9, respectively, per patient per year. In contrast, 49% of 8,703 eligible patients in THRio had a TST ever performed and only 53% of eligible patients started IPT.

CONCLUSION

Physicians are substantially more compliant with HIV monitoring and PCP prophylaxis than with TB prophylaxis guidelines. Efforts to improve TB control in HIV patients are badly needed.

Lower levels of interleukin-12 precede the development of tuberculosis among HIV-infected women

Tuberculosis (TB) is the worldwide leading cause of death among HIV-infected individuals, accounting for more than half of AIDS-related deaths. A high risk of tuberculosis (TB) has been shown in early stages of the HIV disease, even in the presence of normal CD4(+) cell counts. Moreover, the factors that determine protective immunity vs. susceptibility to Mycobacterium tuberculosis cannot be fully explained by simple changes in IFNγ levels or a shift from Th1 to Th2 cytokines. This work investigated the relationship between cytokine expression profiles in peripheral blood mononuclear cells (PBMC) and susceptibility to M. tuberculosis in 10 HIV+ women who went onto develop TB. RNA transcripts for IL-4, IL-4δ2, IL-10, IL-12(p35), IL-13, IL-17A, IFNγ and TNFα were measured by real-time quantitative PCR in unstimulated or TB peptide antigen-stimulated PBMCs from 10 HIV+ women with positive tuberculin skin tests (TST) and compared with HIV-seropositive and seronegative women without previous TB and negative TST. Stimulated PBMC cultures showed significantly lower expression of IL-12p35 (p=0.004) and IL-10 (p=0.026) in the HIV+TB+ group 6-12months before onset of TB compared to HIV+TB- women. Unstimulated PBMC from HIV+TB+ women also had lower expression of Th2 cytokines [IL-4 (p=0.056) and IL-13 (p=0.050)] compared to HIV+TB- women. These results suggest that lower IL-12 production by PBMC in response to TB antigens and lower levels of both Th1 and Th2 cytokines by PBMC correlate with future development of TB in HIV-infected women and may be responsible for their increased susceptibility.

Tuberculosis and AIDS co-morbidity in children: linkage of databases from Espirito Santo State, Brazil

We assessed the prevalence of AIDS among children diagnosed with active tuberculosis (TB) in Espírito Santo State, Brazil, by linking TB and AIDS surveillance databases using Reclink software and SPSS. Among 411 pediatric TB cases from 2000 to 2006, 27 (7%) were co-infected with AIDS. Most children were unable to provide a sputum specimen; co-infected patients were more likely to be smear negative for acid-fast bacilli (83% vs 46%; p = 0.07) and culture positive for Mycobacterium tuberculosis (44% vs 19%; p < 0.001). In all, 57% of co-infected patients did not react to tuberculin skin test compared with 17% of TB patients (p < 0.001). This report emphasizes the significance of AIDS in pediatric TB cases and highlights the importance of evaluating surveillance databases for gaining a better understanding of the burden of co-infection.

Cervical cytology and histopathologic abnormalities in women living with AIDS in São Paulo, Brazil

BACKGROUND

Women living with HIV/AIDS present with a higher prevalence of human papillomavirus (HPV) infection, higher rates of squamous intraepithelial lesions, and are more susceptible to invasive cervical carcinoma progression.

OBJECTIVE

We assessed the frequency of precursory cervical lesions of cancer and its risk factors for women living with HIV/AIDS.

METHODS

Sociodemographic, clinical, behavioral, and laboratory data were collected from medical records from 2008 to 2009 and analyzed using forward stepwise logistic regression.

RESULTS

Medical records of 631 women were reviewed; mean age at AIDS diagnosis was 34 years old (interquartile range = 29-40 years old), 32% were <16 years old at first sexual intercourse; 61% had ≤5 sexual partners during life; 43% had been living with AIDS for ≥9 years; 47% reported previous sexually transmitted infections; 44% presented with HPV infection; and 10% presented with high squamous intraepithelial lesions. Presenting high squamous intraepithelial lesions was significantly associated with home district Human Development Index, age at AIDS diagnosis (>40 years old), time of AIDS diagnosis (>8 years), CD4 cell count <350/mm, and HPV infection.

CONCLUSIONS

Frequent squamous intraepithelial neoplasia in these women shows the importance of gynecologic examinations in routine care and follow-up required by those who present with cervical lesions.

Estimating the extent of underreporting of mortality among HIV-infected individuals in Rio de Janeiro, Brazil

Non-HIV-related causes of death have been increasing after the introduction of highly active antiretroviral therapy. Underlying and contributing causes of death were assessed in respect to the presence/absence of HIV/AIDS among HIV-infected/AIDS patients in Rio de Janeiro, Brazil. Demographic variables (age, gender, ethnicity, and schooling) and CD4 cell counts closest to death were assessed through logistic regression models comparing those who did not have with those who had HIV/AIDS mentioned on the death certificate. The linkage with the two cohorts identified 1249 records, of which 370 (29.6%) did not have HIV/AIDS listed on any field of the death certificate [77 (20.8%) attributed to undefined and 72 (19.5%) to external causes]. After excluding external causes, 25.3% still did not have HIV/AIDS listed on the death certificate. Multiple logistic regression analysis showed that age >40 years (OR = 2.09; 95%CI = 1.49-2.93; p < 0.001) and CD4 cell count closest to the date of death (OR = 1.15; 95% CI = 1.07-1.23; p < 0.001 for 100 cell increase) were associated with an increased probability of not having HIV/AIDS mentioned on the death certificate, when external causes were excluded. Mortality among HIV-infected individuals is underreported in the Rio de Janeiro Mortality Registry, particularly among older individuals and those with higher CD4 counts. Physicians should be aware of the changing patterns of mortality among HIV individuals, and public health officials should regularly perform linkages between all-cause mortality and available HIV-infected patients databases, such as AIDS registries and large cohort studies.

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.

Prevalence of patients with respiratory symptoms through active case finding and diagnosis of pulmonary tuberculosis among prisoners and related predictors in a jail in the city of Carapicuíba, Brazil

BACKGROUND

Prisons offer a fertile setting for the transmission of tuberculosis due to the presence of many classic risk factors for both infection and disease: overcrowding, poor ventilation, and little sunlight. Prisoners are often malnourished and have poor hygiene and are more likely to have a background of alcohol and drug abuse.

OBJECTIVES

To determine the prevalence of prisoners with respiratory symptoms and pulmonary tuberculosis (PTB) through active case finding in a prisoner population of the county jail of Carapicuíba, and to study possible related variables.

METHODS

This was a cross-sectional study, and respiratory symptomatic individuals (RSI) were detected through active case finding. Socio-demographic data were collected from inmates' judicial history using a specific questionnaire. The RSI provided sputum specimens for detection of acid fast bacilli and culture for mycobacterium identification.

RESULTS

Among the 397 prisoners studied, 154 reported respiratory symptoms for more than three weeks, and were considered RSI; the variables associated with RSI were: having already been tried and incarcerated for more than six months and seven were diagnosed as PTB (1,763 cases/ 100,000 inhabitants).

CONCLUSIONS

The prevalence of RSI and PTB cases were respectively 39 and 35 times greater than the general population.

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.

The implementation of isoniazid preventive therapy in HIV clinics: the experience from the TB/HIV in Rio (THRio) study

OBJECTIVE

The TB/HIV in Rio (THRio) study was launched in September 2005 to assess the impact of integrated tuberculosis (TB) and HIV treatment strategies in 29 HIV clinics in Rio de Janeiro, Brazil.

DESIGN

THRio is a cluster-randomized trial (CRT) to determine whether routine screening for and treatment of latent TB in HIV clinic patients with access to antiretroviral therapy will reduce TB incidence at the clinic level. THRio is part of the Consortium to Respond Effectively to AIDS/TB Epidemic that is implementing research studies to assess the impact of bold, new public health paradigms for controlling the AIDS/TB epidemic.

METHODS

Twenty-nine public primary HIV clinics were randomly assigned a date to begin implementing TB screening procedures and provision of isoniazid preventive therapy (IPT) for TB/HIV coinfected patients. Final analysis of the CRT is expected in 2011.

RESULTS

Starting at date of tuberculin skin test (TST)/IPT implementation at each clinic through August 2010, 1670 HIV-infected patients initiated IPT, of which 215 are still receiving treatment. Of the remaining 1455 patients, 1230 (85%) completed therapy and only 20 (1.2%) patients initiating IPT reported adverse reactions leading to discontinuation of therapy. IPT completion was higher among HIV-infected patients receiving HAART (87%) than those not yet receiving HAART (79%, P < 0.01). Times to TST and IPT have markedly decreased postintervention, but remain considerably long. The richness of the THRio database has resulted in several analyses of this expansive cohort of HIV-infected patients that are reviewed here.

CONCLUSIONS

The national implementation of TST and IPT for HIV-positive patients in Brazil has been invigorated partly due to THRio's baseline results. Expanded use of IPT in HIV patients in Rio de Janeiro is achievable with high adherence and low adverse events, although this effort requires a package of activities including training, advocacy and reorganization of services.

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.

Point-of-care Arkansas method for measuring adherence to treatment with isoniazid

We evaluated the accuracy of a point-of-care test designed to measure adherence to isoniazid (INH) preventive therapy in a hospital setting in Rio de Janeiro, Brazil. Patients on treatment with daily INH and patients not receiving INH were included. Sensitivity and specificity of the test were 84%/98% at the first minute, and 95%/98% at the fifth minute, respectively. Among smokers, sensitivity and specificity was reduced (80%/89% at the fifth minute, respectively), but only 17% smoked. This test accurately detected INH metabolites 24h following directly observed INH intake, though sensitivity and specificity may be compromised by tobacco smoke exposure.

Tuberculosis and AIDS co-morbidity in Brazil: linkage of the tuberculosis and AIDS databases

This study evaluated differences in AIDS patients with and without tuberculosis (TB) in Espírito Santo State, Brazil. Standard regional AIDS (SINAN, SISCEL, SICLOM and SIM) and tuberculosis (SINAN) databases were used. TB and AIDS databases were linked using Reclink software, version 3, with SPSS software support to identify co-infected cases. Data from July 2000 to June 2006 in Espírito Santo State were linked. The results showed 3,523 adult AIDS cases and 9,958 adult TB cases resulted in 430 co-infected patients, who were compared to 1,290 AIDS patients who never developed TB. Among 430 co-infected patients, TB was diagnosed first in 223 (51.9%), AIDS was first in 44 (10.2%), and AIDS and TB were diagnosed concurrently in 163 (37.9%). Median age did not differ between co-infected cases (36 years (interquartile range [IQR] 29-43) and non-co-infected cases (34 years; IQR 28-42). Pulmonary tuberculosis was diagnosed in 239 (55.6%); 109 (25.3%) had extra-pulmonary TB and 82 (19.1%) had both presentations. In the final logistic regression model, living in a metropolitan area [Odds Ratio (OR)=1.43 (95% Confidence Interval (CI) 1.05-1.95)], education < 3 years [OR=3.03 (95%CI 1.56-5.88)] and CD4 counts < 200/mm(3) [OR=1.14 (95%CI 1.09-1.18)] were associated with co-infection. This report emphasizes the significance of tuberculosis among AIDS cases in Brazil, and highlights the importance of evaluating secondary data for purposes of improving data quality and developing public health interventions.

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.

Smoking and risk of tuberculosis incidence, mortality, and recurrence in South Korean men and women

The authors explored the association of cigarette smoking with tuberculosis incidence, recurrence, and mortality. A 14-year prospective cohort study (1992-2006) was carried out in 1,294,504 South Koreans. Participants were grouped by smoking history, and the authors assessed tuberculosis incidence, mortality, and recurrence risk for each group. Unadjusted and adjusted Cox proportional hazards models were used to investigate the association between smoking history and the 3 outcomes of interest, adjusting for age and alcohol use. Compared with never smokers, current smokers had increased mortality from tuberculosis among both men (adjusted hazard ratio (HR) = 1.6, 95% confidence interval (CI): 1.3, 2.0) and women (HR = 1.6, 95% CI: 1.0, 2.4). Current male smokers had greater risk of incident tuberculosis than former smokers (HR = 1.4, 95% CI: 1.3, 1.5), and risk among current smokers increased with number of cigarettes smoked daily. In females, cigarette smoking was not associated with incident tuberculosis. There was interaction between smoking and sex for incidence (P = 0.00047). The effect of smoking was generally reduced with adjustment for body mass index. Among men, the highest alcohol consumption category (> or =100 g/day) was associated with risk of incident tuberculosis (HR = 1.5, 95% CI: 1.3, 1.7). This study provides longitudinal evidence that smoking increases risk of incident tuberculosis, mortality from tuberculosis, and tuberculosis recurrence.

Adherence to isoniazid prophylaxis among HIV-infected children: a randomized controlled trial comparing two dosing schedules

BACKGROUND

Tuberculosis contributes significantly to morbidity and mortality among HIV-infected children in sub-Saharan Africa. Isoniazid prophylaxis can reduce tuberculosis incidence in this population. However, for the treatment to be effective, adherence to the medication must be optimized. We investigated adherence to isoniazid prophylaxis administered daily, compared to three times a week, and predictors of adherence amongst HIV-infected children.

METHODS

We investigated adherence to study medication in a two centre, randomized trial comparing daily to three times a week dosing of isoniazid. The study was conducted at two tertiary paediatric care centres in Cape Town, South Africa. Over a 5 year period, we followed 324 HIV-infected children aged >or= 8 weeks. Adherence information based on pill counts was available for 276 children. Percentage adherence was calculated by counting the number of pills returned. Adherence >or= 90% was considered to be optimal. Analysis was done using summary and repeated measures, comparing adherence to the two dosing schedules. Mean percentage adherence (per child during follow-up time) was used to compare the mean of each group as well as the proportion of children achieving an adherence of >or= 90% in each group. For repeated measures, percentage adherence (per child per visit) was dichotomized at 90%. A logistic regression model with generalized estimating equations, to account for within-individual correlation, was used to evaluate the impact of the dosing schedule. Adjustments were made for potential confounders and we assessed potential baseline and time-varying adherence determinants.

RESULTS

The overall adherence to isoniazid was excellent, with a mean adherence of 94.7% (95% confidence interval [CI] 93.5-95.9); similar mean adherence was achieved by the group taking daily medication (93.8%; 95% CI 92.1-95.6) and by the three times a week group (95.5%; 95% CI 93.8-97.2). Two-hundred and seventeen (78.6%) children achieved a mean adherence of >or= 90%. Adherence was similar for daily and three times a week dosing schedules in univariate (odds ratio [OR] 0.88; 95% CI 0.66-1.17; P = 0.38) and multivariate (adjusted OR 0.85; 95% CI 0.64-1.11; P = 0.23) models. Children from overcrowded homes were less adherent (adjusted OR 0.71; 95% CI 0.54-0.95; P = 0.02). Age at study visit was predictive of adherence, with better adherence achieved in children older than 4 years (adjusted OR 1.96; 95% CI 1.16-3.32; P = 0.01).

CONCLUSION

Adherence to isoniazid was excellent regardless of the dosing schedule used. Intermittent dosing of isoniazid prophylaxis can be considered as an alternative to daily dosing, without compromising adherence or efficacy.

TRIAL REGISTRATION

Clinical Trials NCT00330304.

Human papillomavirus in women with and without HIV-1 infection attending an STI clinic in Vitoria, Brazil

We conducted a cross-sectional study in Vitória, Brazil, to assess the prevalence of human papillomavirus (HPV) infection in HIV-positive and HIV-negative women attending a sexually transmitted infection (STI)/AIDS clinic. We also investigated the presence of HPV genotypes and assessed covariates for HIV infection. Enrolled patients received a gynecological evaluation, and cervical scrape samples were collected for cytological analysis and HPV-DNA polymerase chain reaction (PCR). A blood sample was obtained to determine HIV status. HPV infection and squamous intraepithelial lesions were studied in 284 women, 112 (39.4%) HIV-positive women and 172 (60.5%) HIV-negative women. HPV-DNA was detected in 133 (46.8%). HIV-infected women were almost twice as likely to be concurrently infected with HPV than HIV-negative women (OR = 1.87 95% CI: 1.16-3.03). The high proportion of HPV detected among women attending an STI/AIDS clinic, particularly among HIV-infected women, proves the importance of screening this high-risk group in the hope of earlier detection and treatment of cervical intraepithelial neoplasia (CIN).

Impact of diabetes mellitus on treatment outcomes of patients with active tuberculosis

Diabetes mellitus (DM) is an emerging chronic health condition of developed and developing countries. We conducted a retrospective cohort study of patients with active, culture-confirmed tuberculosis (TB) in Maryland to determine the impact of DM on TB treatment outcomes. Of 297 TB patients, 42 (14%) had DM. Patients with diabetes had 2.0 times higher odds of death than patients without diabetes (95% confidence interval [CI] 0.74-5.2, P = 0.18). Adjusting for human immunodeficiency virus (HIV), age, weight, and foreign birth, the odds of death were 6.5 times higher in patients with diabetes than patients without diabetes (95% CI 1.1-38.0, P = 0.039). In pulmonary TB patients, time to sputum culture conversion was longer in patients with diabetes than patients without diabetes (median 49 versus 39 days, P = 0.09). Two-month culture conversion proportions were similar (70% and 69%). Treatment failure occurred in 4.1% of patients without diabetes and 6.7% of patients with diabetes (P = 0.51). In conclusion, DM was a risk factor for death in Maryland TB patients. There was a trend toward increased time to culture conversion; two-month culture conversion proportions, however, were similar.

Isoniazid preventive therapy, HAART and tuberculosis risk in HIV-infected adults in South Africa: a prospective cohort

BACKGROUND

The World Health Organization recommends isoniazid preventive therapy (IPT) for preventing tuberculosis in HIV-infected adults, although few countries have instituted this policy. Both IPT and highly active antiretroviral therapy (HAART) used separately result in reductions in tuberculosis risk. There is less information on the combined effect of IPT and HAART. We assessed the effect of IPT, HAART or both IPT and HAART on tuberculosis incidence in HIV-infected adults in South Africa.

METHODS

Two clinical cohorts of HIV-infected patients were studied. Primary exposures were receipt of IPT and/or HAART and the primary outcome was incident tuberculosis. Crude incident rates and incident rate ratios were calculated and Cox proportional hazards models investigated associations with tuberculosis risk.

RESULTS

Among 2778 HIV-infected patients followed for 4287 person-years, 267 incident tuberculosis cases were diagnosed [incidence rate ratio (IRR)=6.2/100 person-years; 95% CI 5.5-7.0]. For person-time without IPT or HAART, the IRR was 7.1/100 person-years (95% CI 6.2-8.2); for person-time receiving HAART but without IPT, the IRR was 4.6/100 person-years (95% CI 3.4-6.2); for person-time after IPT but prior to HAART, the IRR was 5.2/100 person-years (95% CI 3.4-7.8); during follow-up in patients treated with HAART after receiving IPT the IRR was 1.1/100 person-years (95% CI 0.02-7.6). Compared to treatment-naive patients, HAART-only patients had a 64% decreased hazard for tuberculosis [adjusted hazard ratio (aHR)=0.36; 95% CI 0.25-0.51], and patients receiving HAART after IPT had a 89% reduced hazard (aHR=0.11; 95% CI 0.02-0.78).

CONCLUSION

Tuberculosis risk is significantly reduced by IPT in HAART-treated adults in a high-incidence operational setting in South Africa. IPT is an inexpensive and cost-effective strategy and our data strengthen calls for the implementation of IPT in conjunction with the roll-out of HAART.

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.

Impact and cost-effectiveness of culture for diagnosis of tuberculosis in HIV-infected Brazilian adults

Background

Culture of Mycobacterium tuberculosis currently represents the closest “gold standard” for diagnosis of tuberculosis (TB), but operational data are scant on the impact and cost-effectiveness of TB culture for human immunodeficiency (HIV-) infected individuals in resource-limited settings.

Methodology/Principal Findings

We recorded costs, laboratory results, and dates of initiating TB therapy in a centralized TB culture program for HIV-infected patients in Rio de Janeiro, Brazil, constructing a decision-analysis model to estimate the incremental cost-effectiveness of TB culture from the perspective of a public-sector TB control program. Of 217 TB suspects presenting between January 2006 and March 2008, 33 (15%) had culture-confirmed active tuberculosis; 23 (70%) were smear-negative. Among smear-negative, culture-positive patients, 6 (26%) began TB therapy before culture results were available, 11 (48%) began TB therapy after culture result availability, and 6 (26%) did not begin TB therapy within 180 days of presentation. The cost per negative culture was US$17.52 (solid media)–$23.50 (liquid media). Per 1,000 TB suspects and compared with smear alone, TB culture with solid media would avert an estimated eight TB deaths (95% simulation interval [SI]: 4, 15) and 37 disability-adjusted life years (DALYs) (95% SI: 13, 76), at a cost of $36 (95% SI: $25, $50) per TB suspect or $962 (95% SI: $469, $2642) per DALY averted. Replacing solid media with automated liquid culture would avert one further death (95% SI: −1, 4) and eight DALYs (95% SI: −4, 23) at $2751 per DALY (95% SI: $680, dominated). The cost-effectiveness of TB culture was more sensitive to characteristics of the existing TB diagnostic system than to the accuracy or cost of TB culture.

Conclusions/Significance

TB culture is potentially effective and cost-effective for HIV-positive patients in resource-constrained settings. Reliable transmission of culture results to patients and integration with existing systems are essential.

Validation of a hierarchical deterministic record-linkage algorithm using data from 2 different cohorts of human immunodeficiency virus-infected persons and mortality databases in Brazil

Loss to follow-up is a major source of bias in cohorts of patients with human immunodeficiency virus (HIV) and could lead to underestimation of mortality. The authors developed a hierarchical deterministic linkage algorithm to be used primarily with cohorts of HIV-infected persons to recover vital status information for patients lost to follow-up. Data from patients known to be deceased in 2 cohorts in Rio de Janeiro, Brazil, and data from the Rio de Janeiro State mortality database for 1999-2006 were used to validate the algorithm. A fully automated procedure yielded a sensitivity of 92.9% and specificity of 100% when no information was missing. When the automated procedure was combined with clerical review, in a scenario of 5% death prevalence and 20% missing mothers' names, sensitivity reached 96.5% and specificity 100%. In a practical application, the algorithm significantly increased death rates and decreased the rate of loss to follow-up in the cohorts. The finding that 23.9% of matched records did not give HIV or acquired immunodeficiency syndrome as the cause of death reinforces the need to search all-cause mortality databases and alerts for possible underestimation of death rates. These results indicate that the algorithm is accurate enough to recover vital status information on patients lost to follow-up in cohort studies.

Recurrent tuberculosis in HIV-infected patients in Rio de Janeiro, Brazil

BACKGROUND/OBJECTIVE

The risk of recurrent tuberculosis may increase in HIV-infected patients due to exogenous reinfection. We measured the frequency of and determined risk factors for recurrent tuberculosis in a cohort of HIV-infected patients in Rio de Janeiro, Brazil.

METHODS

Data were abstracted from medical records of HIV-infected patients attending 29 HIV clinics between 1998 and 2007. Patients analyzed were those who had no tuberculosis history prior to their first HIV clinic visit and who had at least one episode of tuberculosis after entry. Incidence rate ratios compared incidence rates between risk groups and Cox proportional hazards regression models evaluated unadjusted and adjusted associations.

RESULTS

Among 1080 HIV-infected patients with tuberculosis, 96 (8.9%) developed a recurrent diagnosis. The median time between diagnoses was 2.4 years. Fewer patients with recurrent tuberculosis had completed their initial 6-month course of tuberculosis treatment compared with patients without recurrence (78 versus 86%; P = 0.02). For patients who completed therapy, the incidence rate of recurrence was 2.5/100 versus 9.0/100 person-years for noncompleters (incidence rate ratio, 3.60; 95% confidence interval, 1.92-6.32). In multivariate modeling, initial tuberculosis treatment completion, receipt of antiretroviral therapy, and CD4 cell count more than 200 mm any time after the initial diagnosis were associated with a significantly decreased hazard of recurrence.

CONCLUSION

Tuberculosis recurrence rates were high in this HIV-infected population. Completion of initial tuberculosis therapy, use of antiretroviral therapy, and increases in CD4 cell counts were associated with lower recurrence rates. Use of secondary preventive therapy might be warranted to reduce the burden of tuberculosis in patients with HIV infection.

AIDS-related tuberculosis in Rio de Janeiro, Brazil

BACKGROUND

We studied the incidence of tuberculosis, AIDS, AIDS deaths and AIDS-TB co-infection at the population level in Rio de Janeiro, Brazil where universal and free access to combination antiretroviral therapy has been available since 1997.

METHODOLOGY/PRINCIPAL FINDINGS

This was a retrospective surveillance database match of Rio de Janeiro databases from 1995-2004. Proportions of tuberculosis occurring within 30 days and between 30 days and 1 year after AIDS diagnosis were determined. Generalized additive models fitted with cubic splines with appropriate estimating methods were used to describe rates and proportions over time. Overall, 90,806 tuberculosis cases and 16,891 AIDS cases were reported; 3,125 tuberculosis cases within 1 year of AIDS diagnosis were detected. Tuberculosis notification rates decreased after 1997 from a fitted rate (fR per 100,000) of 166.5 to 138.8 in 2004. AIDS incidence rates increased 26% between 1995 and 1998 (30.7 to 38.7) followed by a 33.3% decrease to 25.8 in 2004. AIDS mortality rates decreased dramatically after antiretroviral therapy was introduced between 1995 (27.5) and 1999 (13.4). The fitted proportion (fP) of patients with tuberculosis diagnosed within one year of AIDS decreased from 1995 (24.4%) to 1998 (15.2%), remaining stable since. Seventy-five percent of tuberculosis diagnoses after an AIDS diagnosis occurred within 30 days of AIDS diagnosis.

CONCLUSIONS/SIGNIFICANCE

Our results suggest that while combination ART should be considered an essential component of the response to the HIV and HIV/tuberculosis epidemics, it may not be sufficient alone to prevent progression from latent TB to active disease among HIV-infected populations. When tuberculosis is diagnosed prior to or at the same time as AIDS and ART has not yet been initiated, then ART is ineffective as a tuberculosis prevention strategy for these patients. Earlier HIV/AIDS diagnosis and ART initiation may reduce TB incidence in HIV/AIDS patients. More specific interventions will be required if HIV-related tuberculosis incidence is to continue to decline.

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.

Enterotoxigenic bacteroides fragilis: a potential instigator of colitis

BACKGROUND

Inflammatory bowel disease (IBD) is proposed to result from a dysregulated mucosal immune response to the colonic flora in genetically susceptible individuals. Enterotoxigenic Bacteroides fragilis (ETBF), a molecular subclass of the common human commensal, B. fragilis, has been associated with IBD. This study investigated whether ETBF colonization of mice initiated colitis or modified the clinical course of a colitis agonist, dextran sodium sulfate (DSS).

METHODS

Four- and 6-week-old C57BL/6 mice were inoculated with buffer, nontoxigenic B. fragilis (NTBF) strain 9343(pFD340), or ETBF strain 86-5443-2-2 via orogastric tube. A subset of mice received 2% DSS several days pre- or post-inoculation of bacteria. Clinical status was assessed throughout the experiment and severity of colonic inflammation was scored after sacrifice.

RESULTS

All mice, including those receiving DSS, were clinically well prior to bacterial inoculation. NTBF and ETBF colonization was similar. Regardless of mouse age or timing of DSS administration, mice who received ETBF+DSS experienced worse colitis reflected by less weight gain, enhanced gross disease, and greater inflammation in their colons (P < 0.05), especially in the cecum. In particular, younger mice had more extensive disease. Mice inoculated only with ETBF also exhibited colitis with more severe inflammation when compared to all other groups (P < 0.05) except the ETBF+DSS group.

CONCLUSIONS

ETBF, a colonic commensal, alone stimulates colitis and significantly enhances colonic inflammation in DSS-treated mice. This study suggests that acquisition of ETBF colonization may be a potential factor in initiation and/or exacerbation of colitis.

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.

The impact of antiretroviral therapy and isoniazid preventive therapy on tuberculosis incidence in HIV-infected patients in Rio de Janeiro, Brazil

BACKGROUND

Tuberculosis is a common complication and leading cause of death in HIV infection. Antiretroviral therapy (ART) lowers the risk of tuberculosis, but may not be sufficient to control HIV-related tuberculosis. Isoniazid preventive therapy (IPT) reduces tuberculosis incidence significantly, but is not widely used.

METHODS

We analysed tuberculosis incidence in 11 026 HIV-infected patients receiving medical care at 29 public clinics in Rio de Janeiro, Brazil, between 1 September 2003 and 1 September 2005. Data were collected through a retrospective medical record review. We determined rates of tuberculosis in patients who received neither ART nor IPT, only ART, only IPT, or both ART and IPT.

RESULTS

The overall tuberculosis incidence was 2.28 cases/100 person-years (PY) [95% confidence interval (CI) 2.06-2.52]. Among patients who received neither ART nor IPT, incidence was 4.01/100 PY. Patients who received ART had an incidence of 1.90/100 PY (95% CI 1.66-2.17) and those treated with IPT had a rate of 1.27/100 PY (95% CI 0.41-2.95). The incidence among patients who received ART and IPT was 0.80/100 PY (95% CI 0.38-1.47). Multivariate Cox proportional hazards modeling revealed a 76% reduction in tuberculosis risk among patients receiving both ART and IPT (adjusted relative hazard 0.24; P < 0.001) after adjusting for age, previous tuberculosis diagnosis, and CD4 cell counts at baseline.

CONCLUSION

The use of both IPT and ART in HIV-infected patients is associated with significantly reduced tuberculosis incidence. In conjunction with expanded access to ART, the wider use of IPT in patients with HIV will improve tuberculosis control in high burden areas.

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.

Molecular epidemiology of tuberculosis in a low- to moderate-incidence state: are contact investigations enough?

To assess the circumstances of recent transmission of tuberculosis (TB) (progression to active disease <2 years after infection), we obtained DNA fingerprints for 1172 (99%) of 1179 Mycobacterium tuberculosis isolates collected from Maryland TB patients from 1996 to 2000. We also reviewed medical records and interviewed patients with genetically matching M. tuberculosis strains to identify epidemiologic links (cluster investigation). Traditional settings for transmission were defined as households or close relatives and friends; all other settings were considered nontraditional. Of 436 clustered patients, 115 had recently acquired TB. Cluster investigations were significantly more likely than contact investigations to identify patients who recently acquired TB in nontraditional settings (33/42 vs. 23/72, respectively; p<0.001). Transmission from a foreign-born person to a U.S.-born person was rare and occurred mainly in public settings. The time from symptom onset to diagnosis was twice as long for transmitters as for nontransmitters (16.8 vs. 8.5 weeks, respectively; p<0.01). Molecular epidemiologic studies showed that reducing diagnostic delays can prevent TB transmission in nontraditional settings, which elude contact investigations.

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.