Estimated rates of progression to tuberculosis disease for persons infected with Mycobacterium tuberculosis in the United States

BACKGROUND

In the United States, over 80% of tuberculosis (TB) disease cases are estimated to result from reactivation of latent TB infection (LTBI) acquired more than 2 years previously ("reactivation TB"). We estimated reactivation TB rates for the US population with LTBI, overall, by age, sex, race-ethnicity, and US-born status, and for selected comorbidities (diabetes, end-stage renal disease, and HIV).

METHODS

We collated nationally representative data for 2011-2012. Reactivation TB incidence was based on TB cases reported to the National TB Surveillance System that were attributed to LTBI reactivation. Person-years at risk of reactivation TB were calculated using interferon-gamma release assay (IGRA) positivity from the National Health and Nutrition Examination Survey, published values for interferon-gamma release assay sensitivity and specificity, and population estimates from the American Community Survey.

RESULTS

For persons aged ≥6 years with LTBI, the overall reactivation rate was estimated as 0.072 (95% uncertainty interval: 0.047, 0.12) per 100 person-years. Estimated reactivation rates declined with age. Compared to the overall population, estimated reactivation rates were higher for persons with diabetes (adjusted rate ratio [aRR] = 1.6 [1.5, 1.7]), end-stage renal disease (aRR = 9.8 [5.4, 19]), and HIV (aRR = 12 [10, 13]).

CONCLUSIONS

In our study, individuals with LTBI faced small, non-negligible risks of reactivation TB. Risks were elevated for individuals with medical comorbidities that weaken immune function.

Systematic contact investigation: An essential infection prevention skill to prevent tuberculosis transmission in healthcare settings

A systematic approach to contact investigations has long been a cornerstone of interrupting the transmission of tuberculosis in community settings. This paper describes the implementation of a systematic 10-step contact investigation within an acute care setting during a multistate outbreak of healthcare-associated tuberculosis. A systematic approach to contact investigations might have applicability to the prevention of other communicable infections within healthcare settings.

Second Nationwide Tuberculosis Outbreak Caused by Bone Allografts Containing Live Cells - United States, 2023

During July 7-11, 2023, CDC received reports of two patients in different states with a tuberculosis (TB) diagnosis following spinal surgical procedures that used bone allografts containing live cells from the same deceased donor. An outbreak associated with a similar product manufactured by the same tissue establishment (i.e., manufacturer) occurred in 2021. Because of concern that these cases represented a second outbreak, CDC and the Food and Drug Administration worked with the tissue establishment to determine that this product was obtained from a donor different from the one implicated in the 2021 outbreak and learned that the bone allograft product was distributed to 13 health care facilities in seven states. Notifications to all seven states occurred on July 12. As of December 20, 2023, five of 36 surgical bone allograft recipients received laboratory-confirmed TB disease diagnoses; two patients died of TB. Whole-genome sequencing demonstrated close genetic relatedness between positive Mycobacterium tuberculosis cultures from surgical recipients and unused product. Although the bone product had tested negative by nucleic acid amplification testing before distribution, M. tuberculosis culture of unused product was not performed until after the outbreak was recognized. The public health response prevented up to 53 additional surgical procedures using allografts from that donor; additional measures to protect patients from tissue-transmitted M. tuberculosis are urgently needed.

Outbreak of Multidrug-Resistant Tuberculosis - Kansas, 2021-2022

An outbreak of multidrug-resistant (MDR) tuberculosis (TB) involved 13 persons in four households in a low-income, under-resourced urban Kansas community during November 2021-November 2022. A majority of the seven adults identified in the Kansas outbreak were born outside the United States in a country that had experienced an MDR TB outbreak with the same genotype during 2007-2009, whereas most of the six children in the Kansas outbreak were U.S.-born. Prompt identification, evaluation, and treatment of persons with MDR TB and their contacts is essential to limiting transmission.

Recommendations for Use of Video Directly Observed Therapy During Tuberculosis Treatment - United States, 2023

U.S. clinical practice guidelines recommend directly observed therapy (DOT) as the standard of care for tuberculosis (TB) treatment (1). DOT, during which a health care worker observes a patient ingesting the TB medications, has typically been conducted in person. Video DOT (vDOT) uses video-enabled devices to facilitate remote interactions between patients and health care workers to promote medication adherence and clinical monitoring. Published systematic reviews, a published meta-analysis, and a literature search through 2022 demonstrate that vDOT is associated with a higher proportion of medication doses being observed and similar proportions of cases with treatment completion and microbiologic resolution when compared with in-person DOT (2-5). Based on this evidence, CDC has updated the recommendation for DOT during TB treatment to include vDOT as an equivalent alternative to in-person DOT. vDOT can assist health department TB programs meet the U.S. standard of care for patients undergoing TB treatment, while using resources efficiently.

Transmission of Mycobacterium tuberculosis to healthcare personnel resulting from contaminated bone graft material, United States, June 2021- August 2022

A nationwide tuberculosis outbreak linked to a viable bone allograft product contaminated with Mycobacterium tuberculosis was identified in June 2021. Our subsequent investigation identified 73 healthcare personnel with new latent tuberculosis infection following exposure to the contaminated product, product recipients, surgical instruments, or medical waste.

Nationwide tuberculosis outbreak in the USA linked to a bone graft product: an outbreak report

BACKGROUND

Mycobacterium tuberculosis transmission through solid organ transplantation has been well described, but transmission through transplanted tissues is rare. We investigated a tuberculosis outbreak in the USA linked to a bone graft product containing live cells derived from a single deceased donor.

METHODS

In this outbreak report, we describe the management and severity of the outbreak and identify opportunities to improve tissue transplant safety in the USA. During early June, 2021, the US Centers for Disease Control and Prevention (CDC) worked with state and local health departments and health-care facilities to locate and sequester unused units from the recalled lot and notify, evaluate, and treat all identified product recipients. Investigators from CDC and the US Food and Drug Administration (FDA) reviewed donor screening and tissue processing. Unused product units from the recalled and other donor lots were tested for the presence of M tuberculosis using real-time PCR (rt PCR) assays and culture. M tuberculosis isolates from unused product and recipients were compared using phylogenetic analysis.

FINDINGS

The tissue donor (a man aged 80 years) had unrecognised risk factors, symptoms, and signs consistent with tuberculosis. Bone was procured from the deceased donor and processed into 154 units of bone allograft product containing live cells, which were distributed to 37 hospitals and ambulatory surgical centres in 20 US states between March 1 and April 2, 2021. From March 3 to June 1, 2021, 136 (88%) units were implanted into 113 recipients aged 24-87 years in 18 states (some individuals received multiple units). The remaining 18 units (12%) were located and sequestered. 87 (77%) of 113 identified product recipients had microbiological or imaging evidence of tuberculosis disease. Eight product recipients died 8-99 days after product implantation (three deaths were attributed to tuberculosis after recognition of the outbreak). All 105 living recipients started treatment for tuberculosis disease at a median of 69 days (IQR 56-81) after product implantation. M tuberculosis was detected in all eight sequestered unused units tested from the recalled donor lot, but not in lots from other donors. M tuberculosis isolates from unused product and recipients were more than 99·99% genetically identical.

INTERPRETATION

Donor-derived transmission of M tuberculosis via bone allograft resulted in substantial morbidity and mortality. All prospective tissue and organ donors should be routinely assessed for tuberculosis risk factors and clinical findings. When these are present, laboratory testing for M tuberculosis should be strongly considered.

FUNDING

None.

Molecular surveillance for large outbreaks of tuberculosis in the United States, 2014-2018

OBJECTIVE

This study describes characteristics of large tuberculosis (TB) outbreaks in the United States detected using novel molecular surveillance methods during 2014-2016 and followed for 2 years through 2018.

METHODS

We developed 4 genotype-based detection algorithms to identify large TB outbreaks of ≥10 cases related by recent transmission during a 3-year period. We used whole-genome sequencing and epidemiologic data to assess evidence of recent transmission among cases.

RESULTS

There were 24 large outbreaks involving 518 cases; patients were primarily U.S.-born (85.1%) racial/ethnic minorities (84.1%). Compared with all other TB patients, patients associated with large outbreaks were more likely to report substance use, homelessness, and having been diagnosed while incarcerated. Most large outbreaks primarily occurred within residences among families and nonfamilial social contacts. A source case with a prolonged infectious period and difficulties in eliciting contacts were commonly reported contributors to transmission.

CONCLUSION

Large outbreak surveillance can inform targeted interventions to decrease outbreak-associated TB morbidity.

Tuberculosis Outbreaks in State Prisons, United States, 2011-2019

Objectives. To understand the frequency, magnitude, geography, and characteristics of tuberculosis outbreaks in US state prisons. Methods. Using data from the National Tuberculosis Surveillance System, we identified all cases of tuberculosis during 2011 to 2019 that were reported as occurring among individuals incarcerated in a state prison at the time of diagnosis. We used whole-genome sequencing to define 3 or more cases within 2 single nucleotide polymorphisms within 3 years as clustered; we classified clusters with 6 or more cases during a 3-year period as tuberculosis outbreaks. Results. During 2011 to 2019, 566 tuberculosis cases occurred in 41 state prison systems (a median of 3 cases per state). A total of 19 tuberculosis genotype clusters comprising 134 cases were identified in 6 state prison systems; these clusters included a subset of 5 outbreaks in 2 states. Two Alabama outbreaks during 2011 to 2017 totaled 20 cases; 3 Texas outbreaks during 2014 to 2019 totaled 51 cases. Conclusions. Only Alabama and Texas reported outbreaks during the 9-year period; only Texas state prisons had ongoing transmission in 2019. Effective interventions are needed to stop tuberculosis outbreaks in Texas state prisons. (Am J Public Health. 2022;112(8):1170-1179. https://doi.org/10.2105/AJPH.2022.306864).

Epidemiology beyond its limits

In 1995, journalist Gary Taubes published an article in Science titled "Epidemiology faces its limits," which questioned the utility of nonrandomized epidemiologic research and has since been cited more than 1000 times. He highlighted numerous examples of research topics he viewed as having questionable merit. Studies have since accumulated for these associations. We systematically evaluated current evidence of 53 example associations discussed in the article. Approximately one-quarter of those presented as doubtful are now widely viewed as causal based on current evaluations of the public health consensus. They include associations between alcohol consumption and breast cancer, residential radon exposure and lung cancer, and the use of tanning devices and melanoma. This history should inform current debates about the reproducibility of epidemiologic research results.

Tuberculosis Genotype Clusters and Transmission in the U.S., 2009-2018

INTRODUCTION

In the U.S., universal genotyping of culture-confirmed tuberculosis cases facilitates cluster detection. Early recognition of the small clusters more likely to become outbreaks can help prioritize public health resources for immediate interventions.

METHODS

This study used national surveillance data reported during 2009-2018 to describe incident clusters (≥3 tuberculosis cases with matching genotypes not previously reported in the same county); data were analyzed during 2020. Cox proportional hazards regression models were used to examine the patient characteristics associated with clusters doubling in size to ≥6 cases.

RESULTS

During 2009-2018, a total of 1,516 incident clusters (comprising 6,577 cases) occurred in 47 U.S. states; 231 clusters had ≥6 cases. Clusters of ≥6 cases disproportionately included patients who used substances, who had recently experienced homelessness, who were incarcerated, who were U.S. born, or who self-identified as being of American Indian or Alaska Native race or of Black race. A median of 54 months elapsed between the first and the third cases in clusters that remained at 3-5 cases compared with a median of 9.5 months in clusters that grew to ≥6 cases. The longer time between the first and third cases and the presence of ≥1 patient aged ≥65 years among the first 3 cases predicted a lower hazard for accumulating ≥6 cases.

CONCLUSIONS

Clusters accumulating ≥3 cases within a year should be prioritized for intervention. Effective response strategies should include plans for targeted outreach to U.S.-born individuals, incarcerated people, those experiencing homelessness, people using substances, and individuals self-identifying as being of American Indian or Alaska Native race or of Black race.

Factoring Prior Treatment into Tuberculosis Infection Prevalence Estimates, United States, 2011-2012

To refine estimates of how many persons in the United States are candidates for treatment of latent tuberculosis, we removed from analysis persons who self-reported prior treatment on the National Health and Nutrition Examination Survey 2011-2012. We estimate that 12.6 million persons could benefit from treatment to prevent active tuberculosis.

Diabetes mellitus among adults with tuberculosis in the USA, 2010-2017

INTRODUCTION

To describe diabetes trends among adults with incident tuberculosis (TB) disease and examine diabetes-associated TB characteristics and patient outcomes in the USA.

RESEARCH DESIGN AND METHODS

We examined all 71 855 persons aged ≥20 years with incident TB disease reported to the National Tuberculosis Surveillance System during 2010-2017. We performed multivariable logistic regression, comparing characteristics and outcomes among patients with TB reported to have diabetes and those whose diabetes status was unknown.

RESULTS

An overall 18% (n=13 281) of the 71 855 adults with incident TB disease were reported as also having diabetes; the annual proportion increased from 15% in 2010 to 22% in 2017. Among patients aged ≥45 years with both TB and diabetes, the adjusted OR for cavitary or sputum smear-positive TB was 1.7 and 1.5, respectively (95% CIs 1.5 to 1.8 and 1.4 to 1.6). Patients with TB and diabetes had 30% greater odds of dying and took longer to achieve negative Mycobacterium tuberculosis cultures and complete treatment.

CONCLUSIONS

The prevalence of reported diabetes among adults with TB disease has increased. Having diabetes as a comorbidity negatively affects patient outcomes. In accordance with national recommendations, all patients aged ≥45 years and all younger patients who have risk factors for diabetes should be screened for diabetes at the start of TB treatment.

Tuberculosis Infection Among People With Diabetes: United States Population Differences by Race/Ethnicity

INTRODUCTION

Diabetes might confer a modestly increased risk of latent tuberculosis infection, which without treatment can progress to active tuberculosis disease. Three recent analyses of the National Health and Nutrition Examination Survey found a positive association between diabetes and a positive test for Mycobacterium tuberculosis infection. This study examines whether prevalence of a positive test still varies by diabetes status after stratifying by race/ethnicity.

METHODS

This cross-sectional analysis used the public-use National Health and Nutrition Examination Survey 2011-2012 data sets and was conducted in 2018-2019. Interview and examination results for 5,560 adult participants yielded estimates for 219 million U.S. adults in the 4 largest race/ethnicity groups. The weighted prevalence of positive tuberculin skin test or interferon-gamma release assay by diabetes status was ascertained in each group.

RESULTS

Among white and black adults, diabetes was associated with no difference in positive skin test prevalence and little difference in positive interferon-gamma release assay prevalence. The positive assay prevalence difference was +14.5% (95% CI=2.3%, 26.7%) among Hispanic and +9.9% (95% CI=1.2%, 18.6%) among Asian adults, when comparing those with diabetes with those with neither diabetes nor prediabetes. Based on assay results, 23.6% (95% CI=14.0%, 36.9%) of Hispanic and 27.2% (95% CI=19.6%, 36.5%) of Asian adults with diabetes also had latent tuberculosis infection.

CONCLUSIONS

Hispanic and Asian subpopulation results drove much of the previously reported positive association between diabetes and a positive test for M. tuberculosis infection. Hispanic and Asian adults with diabetes might particularly benefit from screening and treatment for latent tuberculosis infection.

Bacillus Calmette-Guérin Cases Reported to the National Tuberculosis Surveillance System, United States, 2004-2015

Mycobacterium bovis bacillus Calmette-Guérin (BCG) is used as a vaccine to protect against disseminated tuberculosis (TB) and as a treatment for bladder cancer. We describe characteristics of US TB patients reported to the National Tuberculosis Surveillance System (NTSS) whose disease was attributed to BCG. We identified 118 BCG cases and 91,065 TB cases reported to NTSS during 2004-2015. Most patients with BCG were US-born (86%), older (median age 75 years), and non-Hispanic white (81%). Only 17% of BCG cases had pulmonary involvement, in contrast with 84% of TB cases. Epidemiologic features of BCG cases differed from TB cases. Clinicians can use clinical history to discern probable BCG cases from TB cases, enabling optimal clinical management. Public health agencies can use this information to quickly identify probable BCG cases to avoid inappropriately reporting BCG cases to NTSS or expending resources on unnecessary public health interventions.

Simple Estimates for Local Prevalence of Latent Tuberculosis Infection, United States, 2011-2015

We used tuberculosis genotyping results to derive estimates of prevalence of latent tuberculosis infection in the United States. We estimated <1% prevalence in 1,981 US counties, 1%–<3% in 785 counties, and >3% in 377 counties. This method for estimating prevalence could be applied in any jurisdiction with an established tuberculosis surveillance system.

Factors Associated With All-Cause Mortality Among Patients With Multidrug-Resistant Tuberculosis-United States, 1993-2013

We assessed characteristics associated with all-cause mortality among US patients with multidrug-resistant tuberculosis. Mortality decreased from 31% during 1993-2002 to 11% during 2003-2013. Directly observed therapy coverage increased from 74% to 95% and was protective against all-cause mortality after accounting for demographics, clinical characteristics, human immunodeficiency virus status, and period of treatment.

Tuberculosis Among Incarcerated Hispanic Persons in the United States, 1993-2014

We examined the National tuberculosis surveillance system to describe Hispanic persons who were incarcerated at time of tuberculosis (TB) diagnosis and to compare their characteristics with those of non-Hispanic incarcerated TB patients. After declines between 1993 and 2002, the annual proportion of Hispanic TB patients who were incarcerated grew from 4.9% in 2003 to 8.4% in 2014. During 2003-2014, 19% of incarcerated US-born TB patients were Hispanic, and 86% of the foreign-born were Hispanic. Most incarcerated TB patients were in local jails, but about a third of all foreign-born Hispanics were in the facility category that includes Immigration and Customs Enforcement detention centers. Foreign birth and recent U.S. arrival characterized many Hispanic persons receiving a TB diagnosis while incarcerated. Hispanic patients had twice the odds of being in federal prisons. Systematic efforts to identify TB infection and disease might lead to early diagnoses and prevention of future cases.

Outbreak of Drug-Resistant Mycobacterium tuberculosis Among Homeless People in Atlanta, Georgia, 2008-2015

OBJECTIVES

Our objective was to describe and determine the factors contributing to a recent drug-resistant tuberculosis (TB) outbreak in Georgia.

METHODS

We defined an outbreak case as TB diagnosed from March 2008 through December 2015 in a person residing in Georgia at the time of diagnosis and for whom (1) the genotype of the Mycobacterium tuberculosis isolate was consistent with the outbreak strain or (2) TB was diagnosed clinically without a genotyped isolate available and connections were established to another outbreak-associated patient. To determine factors contributing to transmission, we interviewed patients and reviewed health records, homeless facility overnight rosters, and local jail booking records. We also assessed infection control measures in the 6 homeless facilities involved in the outbreak.

RESULTS

Of 110 outbreak cases in Georgia, 86 (78%) were culture confirmed and isoniazid resistant, 41 (37%) occurred in people with human immunodeficiency virus coinfection (8 of whom were receiving antiretroviral treatment at the time of TB diagnosis), and 10 (9%) resulted in TB-related deaths. All but 8 outbreak-associated patients had stayed overnight or volunteered extensively in a homeless facility; all these facilities lacked infection control measures. At least 9 and up to 36 TB cases outside Georgia could be linked to this outbreak.

CONCLUSIONS

This article highlights the ongoing potential for long-lasting and far-reaching TB outbreaks, particularly among populations with untreated human immunodeficiency virus infection, mental illness, substance abuse, and homelessness. To prevent and control TB outbreaks, health departments should work with overnight homeless facilities to implement infection control measures and maintain searchable overnight rosters.

Tuberculosis Outbreaks in the United States, 2009-2015

OBJECTIVES

The Centers for Disease Control and Prevention provides on-site epidemiologic assistance for outbreak response when the health capacity of state, tribal, local, and territorial health departments has been exceeded. We examined recent outbreaks of tuberculosis (TB) for which health departments needed assistance.

METHODS

We defined a TB outbreak as detection of ≥3 TB cases related by transmission, as suggested by routine genotyping and epidemiologic linkages. We conducted retrospective reviews of documentation from all 21 TB outbreak investigations in the United States for which the Centers for Disease Control and Prevention provided on-site assistance during 2009-2015. We abstracted data on patients' demographic characteristics and TB risk factors, as well as factors contributing to the outbreak from trip reports written by on-site investigators, and we compared these with outbreaks investigated during 2002-2008.

RESULTS

The 21 TB outbreaks during 2009-2015 involved 457 outbreak patients (range, 3-99 patients per outbreak). Of the 21 outbreaks, 16 were first identified through genotype data. In sum, 118 (26%) patients were identified through contact investigations of other patients in the outbreak. Most outbreak patients (n = 363, 79%) were US born. Ninety-two (26%) patients had a mental illness, 204 (45%) had been homeless in the year before diagnosis, and 379 (83%) used alcohol excessively or used illicit substances. The proportion of patients experiencing homelessness doubled between 2002-2008 and 2009-2015; other characteristics were similar between the 2 periods. Delayed TB diagnosis contributed to unmitigated transmission in all but 1 outbreak.

CONCLUSIONS

TB outbreaks challenge frontline public health resources. Genotyping and contact investigations are important strategies for detecting and controlling TB outbreaks, particularly among people experiencing homelessness or those with mental illness.

Factors associated with recurrent tuberculosis more than 12 months after treatment completion

SETTING

Even among persons who have completed a course of treatment for their first tuberculosis (TB) episode, patients with a history of TB are at higher risk for having TB.

OBJECTIVE

To describe factors from the initial TB episode associated with recurrent TB among patients who completed treatment and remained free of TB for at least 12 months.

DESIGN

During 1993-2006, US TB cases stratified by birth origin were examined. Cox proportional hazards regression was used to assess the association of factors during the initial episode with recurrence at least 12 months after treatment completion.

RESULTS

Among 632 US-born patients, TB recurrence was associated with age 25-44 years (adjusted hazard ratio [aHR] 1.77, 99% confidence interval [CI] 1.02-3.09, attributable fraction [AF] 1-34%), substance use (aHR 1.57, 99%CI 1.23-2.02, AF 8-22%), and treatment supervised by health departments (aHR 1.42, 99%CI 1.03-1.97, AF 2-28%). Among 211 foreign-born patients, recurrence was associated with human immunodeficiency virus infection (aHR 2.24, 99%CI 1.27-3.98, AF 2-9%) and smear-positive TB (aHR 1.56, 99%CI 1.06-2.30, AF 3-33%).

CONCLUSION

Factors associated with recurrence differed by origin of birth, and might be useful for anticipating greater risk for recurrent TB among certain patients with a history of TB.

Tuberculosis in Jails and Prisons: United States, 2002-2013

OBJECTIVES

To describe cases and estimate the annual incidence of tuberculosis in correctional facilities.

METHODS

We analyzed 2002 to 2013 National Tuberculosis Surveillance System case reports to characterize individuals who were employed or incarcerated in correctional facilities at time they were diagnosed with tuberculosis. Incidence was estimated with Bureau of Justice Statistics denominators.

RESULTS

Among 299 correctional employees with tuberculosis, 171 (57%) were US-born and 82 (27%) were female. Among 5579 persons incarcerated at the time of their tuberculosis diagnosis, 2520 (45%) were US-born and 495 (9%) were female. Median estimated annual tuberculosis incidence rates were 29 cases per 100 000 local jail inmates, 8 per 100 000 state prisoners, and 25 per 100 000 federal prisoners. The foreign-born proportion of incarcerated men 18 to 64 years old increased steadily from 33% in 2002 to 56% in 2013. Between 2009 and 2013, tuberculosis screenings were reported as leading to 10% of diagnoses among correctional employees, 47% among female inmates, and 42% among male inmates.

CONCLUSIONS

Systematic screening and treatment of tuberculosis infection and disease among correctional employees and incarcerated individuals remain essential to tuberculosis prevention and control.

Leveling of Tuberculosis Incidence - United States, 2013-2015

After 2 decades of progress toward tuberculosis (TB) elimination with annual decreases of ≥0.2 cases per 100,000 persons (1), TB incidence in the United States remained approximately 3.0 cases per 100,000 persons during 2013-2015. Preliminary data reported to the National Tuberculosis Surveillance System indicate that TB incidence among foreign-born persons in the United States (15.1 cases per 100,000) has remained approximately 13 times the incidence among U.S.-born persons (1.2 cases per 100,000). Resuming progress toward TB elimination in the United States will require intensification of efforts both in the United States and globally, including increasing U.S. efforts to detect and treat latent TB infection, strengthening systems to interrupt TB transmission in the United States and globally, accelerating reductions in TB globally, particularly in the countries of origin for most U.S.

Characteristics of tuberculosis cases that started outbreaks in the United States, 2002-2011

A review of 26 tuberculosis outbreaks in the United States (2002–2011) showed that initial source case-patients had long infectious periods (median 10 months) and were characterized by substance abuse, incarceration, and homelessness. Improved timeliness of diagnosis and thorough contact investigations for such cases may reduce the risk for outbreaks.

Substantial overlap between incarceration and tuberculosis in atlanta, georgia, 2011

Standard tuberculosis case reporting captures incarceration at diagnosis only. This retrospective analysis of 106 US-born adults with prevalent tuberculosis in 2011 found that 46.2% had documented histories of being in jail or prison, including 16.0% during the year before diagnosis.

Parental perceptions of family and pediatrician roles in childhood weight management

OBJECTIVE

To characterize parental perceptions of the respective roles of families and the pediatrician in childhood weight management.

STUDY DESIGN

Structured in-person interviews (n = 69) were conducted with parents of children ages 3-12 years visiting a pediatric clinic. Interview topics included perceptions of weight and associated problems, child weight status and concerns, and the pediatrician's role in weight management. Interviews were coded qualitatively and analyzed thematically.

RESULTS

Nine major themes were developed from the findings. Parents were clear about the health consequences of excess weight but were not clear about the concept of body mass index, often relying on visual cues or symptoms to identify excess weight. Parents relied on pediatricians to identify weight problems and suggest diet and exercise plans, but few recognized them as a link to additional weight-management resources. Parents were divided on the role of the pediatrician in managing child weight and were most interested in receiving tailored nutrition information. Parents preferred family behavioral change strategies over singling out an overweight child. Although parents did not always define their child as overweight, many parents of overweight children did express concerns about their child's weight.

CONCLUSIONS

Parents believe that pediatricians have a central role in identifying childhood weight problems by completing screening tests such as body mass index assessments, interpreting the health implications, and communicating those implications to parents. Ensuring that parents understand the health implications of excess weight is critical given gaps in parental knowledge and confidence with healthy lifestyle changes as well as parental ambivalence toward child-directed interventions.

Tuberculosis among the homeless, United States, 1994-2010

OBJECTIVES

1) To describe homeless persons diagnosed with tuberculosis (TB) during the period 1994-2010, and 2) to estimate a TB incidence rate among homeless persons in the United States.

METHODS

TB cases reported to the National Tuberculosis Surveillance System were analyzed by origin of birth. Incidence rates were calculated using the US Department of Housing and Urban Development homeless population estimates. Analysis of genotyping results identified clustering as a marker for transmission among homeless TB patients.

RESULTS

Of 270,948 reported TB cases, 16,527 (6%) were homeless. The TB incidence rate among homeless persons ranged from 36 to 47 cases per 100,000 population in 2006-2010. Homeless TB patients had over twice the odds of not completing treatment and of belonging to a genotype cluster. US- and foreign-born homeless TB patients had respectively 8 and 12 times the odds of substance abuse.

CONCLUSIONS

Compared to the general population, homeless persons had an approximately 10-fold increase in TB incidence, were less likely to complete treatment and more likely to abuse substances. Public health outreach should target homeless populations to reduce the excess burden of TB in this population.

A missed tuberculosis diagnosis resulting in hospital transmission

OBJECTIVE

To find the source of tuberculin skin test conversions among 38 hospital employees on 1 floor during routine testing January-February 2010.

METHODS

Record review of patients at a private hospital during September-December 2009 and interviews with hospital employees. Names of patients from the state tuberculosis (TB) registry were cross-referenced with hospital records for admissions. Mycobacterium tuberculosis genotype results in the county and adjacent counties were examined, and contacts were evaluated for TB infection and disease.

RESULTS

One of the 38 employees, a nurse, was diagnosed with pulmonary TB with a matching M. tuberculosis genotype and drug resistance pattern (isoniazid monoresistant) to those of a county jail inmate also recently diagnosed with pulmonary TB. The nurse had no known contact with that inmate; however, another inmate in his 20's from the same jail had been hospitalized under that nurse's care in October 2009. That young man died, and a postmortem examination result subsequently confirmed TB, which had not been suspected. Exposure to this man with undiagnosed TB could explain the transmission: 87 (27%) of the 318 hospital-based contacts without previous positive tuberculin skin test results were infected, and 9 contacts had active TB.

CONCLUSIONS

This investigation demonstrated M. tuberculosis transmission in a hospital due to a missed diagnosis and nonadherence to national TB infection control guidelines. Routine TB screening of employees allowed early detection of this missed TB diagnosis, facilitating prompt evaluation of contacts. Healthcare providers should suspect TB in symptomatic persons and adhere to TB control policies.

Prioritizing tuberculosis clusters by genotype for public health action, Washington, USA

Groups of tuberculosis cases with indistinguishable Mycobacterium tuberculosis genotypes (clusters) might represent recent transmission. We compared geospatial concentration of genotype clusters with independent priority rankings determined by local public health officials; findings were highly correlated. Routine use of geospatial statistics could help health departments identify recent disease transmission.

Using statistical methods and genotyping to detect tuberculosis outbreaks

Background

Early identification of outbreaks remains a key component in continuing to reduce the burden of infectious disease in the United States. Previous studies have applied statistical methods to detect unexpected cases of disease in space or time. The objectives of our study were to assess the ability and timeliness of three spatio-temporal methods to detect known outbreaks of tuberculosis.

Methods

We used routinely available molecular and surveillance data to retrospectively assess the effectiveness of three statistical methods in detecting tuberculosis outbreaks: county-based log-likelihood ratio, cumulative sums, and a spatial scan statistic.

Results

Our methods identified 8 of the 9 outbreaks, and 6 outbreaks would have been identified 1–52 months (median = 10 months) before local public health authorities identified them. Assuming no delays in data availability, 46 (59.7%) of the 77 patients in the 9 outbreaks were identified after our statistical methods would have detected the outbreak but before local public health authorities became aware of the problem.

Conclusions

Statistical methods, when applied retrospectively to routinely collected tuberculosis data, can successfully detect known outbreaks, potentially months before local public health authorities become aware of the problem. The three methods showed similar results; no single method was clearly superior to the other two. Further study to elucidate the performance of these methods in detecting tuberculosis outbreaks will be done in a prospective analysis.

Epidemiology of recurrent tuberculosis in the United States, 1993-2010

Recurrent tuberculosis (TB) can result from reactivation of a previous TB episode or reinfection with a new Mycobacterium tuberculosis strain. A retrospective analysis of all recurrent TB cases reported in the United States during 1993-2010 was conducted. The proportion of recurrent cases remained stable during the study period (annual range 4.2-5.7%). Compared with persons without a previous diagnosis of TB, persons with recurrent TB experienced lower treatment completion within 12 months and higher mortality during the recurrent episode. Persons with recurrent TB have poorer outcomes, suggesting the need for targeted interventions to ensure treatment completion.

Tuberculosis among healthcare workers, United States, 1995-2007

OBJECTIVE

We examined surveillance data to describe the epidemiology of tuberculosis (TB) among healthcare workers (HCWs) in the United States during the period 1995-2007.

DESIGN

Cross-sectional descriptive analysis of existing surveillance data.

SETTING AND PARTICIPANTS

TB cases reported to the Centers for Disease Control and Prevention from the 50 states and the District of Columbia from 1995 through 2007.

RESULTS

Of the 200,744 reported TB cases in persons 18 years of age or older, 6,049 (3%) occurred in individuals who were classified as HCWs. HCWs with TB were more likely than other adults with TB to be women (unadjusted odds ratio [95% confidence interval], 4.1 [3.8-4.3]), be foreign born (1.3 [1.3-1.4]), have extrapulmonary TB (1.6 [1.5-1.7]), and complete TB treatment (2.5 [2.3-2.8]).

CONCLUSIONS

Healthcare institutions may benefit from intensifying TB screening of HCWs upon hire, especially persons from countries with a high incidence of TB, and encouraging treatment for latent TB infection among HCWs to prevent progression to TB disease.

Outbreak of tuberculosis among Guatemalan immigrants in rural Minnesota, 2008

OBJECTIVES

We described the outbreak investigation and control measures after the Minnesota Department of Health identified a cluster of tuberculosis (TB) cases among Guatemalan immigrants within three rural Minnesota counties in August 2008.

METHODS

TB cases were diagnosed by tuberculin skin test followed by chest radiography and sputum testing for Mycobacterium tuberculosis (M. tuberculosis). We reviewed medical records, interviewed patients, and completed a contact investigation for each infectious case. We used isolate genotyping to confirm epidemiologic links between cases.

RESULTS

The index case was a six-month-old U.S.-born male with Guatemalan parents. Although he experienced four months of cough and fever, TB was not considered at two medical visits but was diagnosed upon hospitalization in May 2008. The presumed source of infection was a Guatemalan male aged 25 years who sang in a band that practiced in the infant's house and whose pulmonary TB was diagnosed at hospitalization in June 2008, despite his having sought medical attention for symptoms seven months earlier. Among the 16 identified TB cases, 14 were outbreak-related. Three genetically distinct M. tuberculosis strains circulated. Of 150 contacts of the singer, 62 (41%) had latent TB infection and 13 (9%), including 10 children, had TB disease.

CONCLUSIONS

In this outbreak, delayed diagnoses contributed to M. tuberculosis transmission. Isolate genotyping corroborated the social links between outbreak-related patients. More timely diagnosis of TB among immigrants and their children can prevent TB transmission among communities in rural, low-incidence areas that might have limited resources for contact investigations.

Tuberculosis outbreak investigations in the United States, 2002-2008

To understand circumstances of tuberculosis transmission that strain public health resources, we systematically reviewed Centers for Disease Control and Prevention (CDC) staff reports of US outbreaks in which CDC participated during 2002–2008 that involved >3 culture-confirmed tuberculosis cases linked by genotype and epidemiology. Twenty-seven outbreaks, representing 398 patients, were reviewed. Twenty-four of the 27 outbreaks involved primarily US-born patients; substance abuse was another predominant feature of outbreaks. Prolonged infectiousness because of provider- and patient-related factors was common. In 17 outbreaks, a drug house was a notable contributing factor. The most frequently documented intervention to control the outbreak was prioritizing contacts according to risk for infection and disease progression to ensure that the highest risk contacts were completely evaluated. US-born persons with reported substance abuse most strongly characterized the tuberculosis outbreaks in this review. Substance abuse remains one of the greatest challenges to controlling tuberculosis transmission in the United States.

Two tuberculosis genotyping clusters, one preventable outbreak

In 2006, eight community tuberculosis (TB) cases and a ninth incarceration-related case were identified during an outbreak investigation, which included genotyping of all Mycobacterium tuberculosis isolates. In 1996, the source patient had pulmonary TB but completed only two weeks of treatment. From February 2005 to May 2006, the source patient lived in four different locations while contagious. The outbreak cases had matching isolate spoligotypes; however, the mycobacterial interspersed repetitive unit (MIRU) patterns from isolates from two secondary cases differed by one tandem repeat at a single MIRU locus. The source patient's isolates showed a mixed mycobacterial population with both MIRU patterns. Traditional and molecular epidemiologic methods linked eight secondary TB cases to a single source patient whose incomplete initial treatment, incarceration, delayed diagnosis, and housing instability resulted in extensive transmission. Adequate treatment of the source patient's initial TB or early diagnosis of recurrent TB could have prevented this outbreak.

Tuberculosis genotyping in six low-incidence States, 2000-2003

BACKGROUND

As tuberculosis incidence declines in the United States, a new tool for TB control efforts is Mycobacterium tuberculosis genotyping. Colorado, Iowa, Montana, New Hampshire, West Virginia, and Wisconsin began routine genotyping of all culture-confirmed TB cases in October 2000.

METHODS

M. tuberculosis isolates from cases reported October 2000 through December 2003 were genotyped by spoligotyping, mycobacterial interspersed repetitive units, and IS6110-based restriction fragment length polymorphism methods. Genotyping results were linked to demographic variables from national surveillance records. Patients who were in genotype clusters were interviewed and their records reviewed to determine possible transmission links among clustered patients. Final analysis was completed during April 2004 through June 2005.

RESULTS

Of 971 reported TB cases, 774 (80%) were culture-confirmed, of which 728 (94%) were genotyped. Most genotyped isolates (634 [87%]) were unique. Within 36 clusters linking 94 individuals, four clusters involved both U.S.- and foreign-born individuals. For eight clusters, genotyping results led to the discovery of previously unsuspected transmission. Transmission links between individuals were established in 21 (58%) of the 36 clusters.

CONCLUSIONS

In these six low-incidence states, most isolates had unique genotypes, suggesting that most cases arose from activation of latent infection. Few TB clusters involved the foreign-born. For 58% of genotype clusters, epidemiologic investigation ascertained that clustering represented recent M. tuberculosis transmission.

Tuberculosis outbreak in marijuana users, Seattle, Washington, 2004

Matching Mycobacterium tuberculosis isolates were noted among 11 young tuberculosis patients socially linked through illicit drug-related activities. A large proportion of their friends, 14 (64%) of 22, had positive tuberculin skin-test results. The behavior of "hotboxing" (smoking marijuana inside a closed car with friends to repeatedly inhale exhaled smoke) fueled transmission.

Tuberculosis and homelessness in the United States, 1994-2003

CONTEXT

Tuberculosis (TB) rates among US homeless persons cannot be calculated because they are not included in the US Census. However, homelessness is often associated with TB.

OBJECTIVES

To describe homeless persons with TB and to compare risk factors and disease characteristics between homeless and nonhomeless persons with TB.

DESIGN AND SETTING

Cross-sectional analysis of all verified TB cases reported into the National TB Surveillance System from the 50 states and the District of Columbia from 1994 through 2003.

MAIN OUTCOME MEASURES

Number and proportion of TB cases associated with homelessness, demographic characteristics, risk factors, disease characteristics, treatment, and outcomes.

RESULTS

Of 185,870 cases of TB disease reported between 1994 and 2003, 11,369 were among persons classified as homeless during the 12 months before diagnosis. The annual proportion of cases associated with homelessness was stable (6.1%-6.7%). Regional differences occurred with a higher proportion of TB cases associated with homelessness in western and some southern states. Most homeless persons with TB were male (87%) and aged 30 to 59 years. Black individuals represented the highest proportion of TB cases among the homeless and nonhomeless. The proportion of homeless persons with TB who were born outside the United States (18%) was lower than that for nonhomeless persons with TB (44%). At the time of TB diagnosis, 9% of homeless persons were incarcerated, usually in a local jail; 3% of nonhomeless persons with TB were incarcerated. Compared with nonhomeless persons, homeless persons with TB had a higher prevalence of substance use (54% alcohol abuse, 29.5% noninjected drug use, and 14% injected drug use), and 34% of those tested had coinfection with human immunodeficiency virus. Compared with nonhomeless persons, TB disease in homeless persons was more likely to be infectious but not more likely to be drug resistant. Health departments managed 81% of TB cases in homeless persons. Directly observed therapy, used for 86% of homeless patients, was associated with timely completion of therapy. A similar proportion in both groups (9%) died from any cause during therapy.

CONCLUSIONS

Individual TB risk factors often overlap with risk factors for homelessness, and the social contexts in which TB occurs are often complex and important to consider in planning TB treatment. Nevertheless, given good case management, homeless persons with TB can achieve excellent treatment outcomes.

Vaccine effectiveness during a varicella outbreak among schoolchildren: Utah, 2002-2003

OBJECTIVES

In the context of a chickenpox outbreak involving 2 Utah elementary schools, we conducted an investigation to assess vaccine effectiveness, describe illness severity, and examine risk factors for breakthrough varicella (ie, varicella in those who have been vaccinated).

METHODS

All parents were asked to complete a questionnaire about their child's medical history. Parents of children with recent varicella were interviewed, and vaccination records were verified. Lesions were submitted for polymerase chain reaction testing.

RESULTS

Questionnaires were returned for 558 (93%) of 597 students in school A and 924 (97%) of 952 students in school B. A total of 83 schoolchildren (57 unvaccinated and 26 vaccinated) had varicella during the October 2002 through February 2003 outbreak period. An additional 17 cases occurred among household contacts, including infants and adults. Polymerase chain reaction analysis recovered wild-type varicella. Vaccine effectiveness was 87%. With 1 notable exception, vaccinated children tended to have milder illness. Risk factors for breakthrough varicella included eczema, vaccination > or =5 years before the outbreak, and vaccination at < or =18 months of age. Restricting analysis to children vaccinated > or =5 years before the outbreak, those vaccinated at < or =18 months of age were more likely to develop breakthrough varicella (relative risk: 9.3; 95% confidence interval: 1.3-68.9).

CONCLUSIONS

The vaccine, administered by >100 health care providers to 571 children during a 7-year time period, was effective. Risk factors for breakthrough varicella suggest some degree of biological interaction between age at vaccination and time since vaccination.

Coccidioidomycosis among workers at an archeological site, northeastern Utah

In 2001, an outbreak of acute respiratory disease occurred among persons working at a Native American archeological site at Dinosaur National Monument in northeastern Utah. Epidemiologic and environmental investigations were undertaken to determine the cause of the outbreak. A clinical case was defined by the presence of at least two of the following symptoms: self-reported fever, shortness of breath, or cough. Ten workers met the clinical case definition; 9 had serologic confirmation of coccidioidomycosis, and 8 were hospitalized. All 10 were present during sifting of dirt through screens on June 19; symptoms began 9–12 days later (median 10). Coccidioidomycosis also developed in a worker at the site in September 2001. A serosurvey among 40 other Dinosaur National Monument workers did not find serologic evidence of recent infection. This outbreak documents a new endemic focus of coccidioidomycosis, extending northward its known geographic distribution in Utah by approximately 200 miles.

Neurologic manifestations and outcome of West Nile virus infection

CONTEXT

The neurologic manifestations, laboratory findings, and outcome of patients with West Nile virus (WNV) infection have not been prospectively characterized.

OBJECTIVE

To describe prospectively the clinical and laboratory features and long-term outcome of patients with neurologic manifestations of WNV infection.

DESIGN, SETTING, AND PARTICIPANTS

From August 1 to September 2, 2002, a community-based, prospective case series was conducted in St Tammany Parish, La. Standardized clinical data were collected on patients with suspected WNV infection. Confirmed WNV-seropositive patients were reassessed at 8 months.

MAIN OUTCOME MEASURES

Clinical, neurologic, and laboratory features at initial presentation, and long-term neurologic outcome.

RESULTS

Sixteen (37%) of 39 suspected cases had antibodies against WNV; 5 had meningitis, 8 had encephalitis, and 3 had poliomyelitis-like acute flaccid paralysis. Movement disorders, including tremor (15 [94%]), myoclonus (5 [31%]), and parkinsonism (11 [69%]), were common among WNV-seropositive patients. One patient died. At 8-month follow-up, fatigue, headache, and myalgias were persistent symptoms; gait and movement disorders persisted in 6 patients. Patients with WNV meningitis or encephalitis had favorable outcomes, although patients with acute flaccid paralysis did not recover limb strength.

CONCLUSIONS

Movement disorders, including tremor, myoclonus, and parkinsonism, may be present during acute illness with WNV infection. Some patients with WNV infection and meningitis or encephalitis ultimately may have good long-term outcome, although an irreversible poliomyelitis-like syndrome may result.

Acute flaccid paralysis and West Nile virus infection

Acute weakness associated with West Nile virus (WNV) infection has previously been attributed to a peripheral demyelinating process (Guillain-Barré syndrome); however, the exact etiology of this acute flaccid paralysis has not been systematically assessed. To thoroughly describe the clinical, laboratory, and electrodiagnostic features of this paralysis syndrome, we evaluated acute flaccid paralysis that developed in seven patients in the setting of acute WNV infection, consecutively identified in four hospitals in St. Tammany Parish and New Orleans, Louisiana, and Jackson, Mississippi. All patients had acute onset of asymmetric weakness and areflexia but no sensory abnormalities. Clinical and electrodiagnostic data suggested the involvement of spinal anterior horn cells, resulting in a poliomyelitis-like syndrome. In areas in which transmission is occurring, WNV infection should be considered in patients with acute flaccid paralysis. Recognition that such weakness may be of spinal origin may prevent inappropriate treatment and diagnostic testing.