Screening for tuberculosis and the use of a borderline zone for the interpretation of the interferon-γ release assay (IGRA) in Portuguese healthcare workers

Introduction

The effect of using a borderline zone for the interpretation of the interferon-γ release assay (IGRA) on the prediction of progression to active tuberculosis (TB) in healthcare workers (HCW) is analysed.

Methods

Data from a published study on TB screening in Portuguese HCW is reanalysed using a borderline zone for the interpretation of the IGRA. Testing was performed with the QuantiFERON-TB Gold In-Tube (QFT). The borderline zone for the QFT was defined as interferon (INF) in QFT ≥0.2 to <0.7 IU/mL. An X-ray was performed when the IGRA was positive (≥0.35 IU/mL) or typical symptoms were present. Sputum analysis was performed according to the X-ray or the presence of typical symptoms.

Results

The cohort comprised 2,884 HCW with a QFT that could be interpreted. In 1,780 (61.7%) HCW, the QFT was <0.2 IU/mL. A borderline result was found in 341 (11.8%) and a QFT >0.7 IU/mL in 763 (26.3%) HCW. Fifty-seven HCW had a TB in their medical history, eight had a TB at the time of screening and progression to active TB was observed in four HCW. Two out of eight HCW (25%) with active TB at the time of screening had a QFT result falling into the borderline zone. One out of four HCW (25%) who progressed towards active TB after being tested with QFT had QFT results falling into the borderline zone. A second IGRA was performed in 1,199 HCW. In total, 292 (24.4%) HCW had at least one of the two IGRA results pertaining to the borderline zone.

Conclusion

Using a borderline zone for the QFT from 0.2 to 0.7 IU/mL should be administered with care, as active TB as well as progression to active TB might be overlooked. Therefore, the borderline zone should be restricted to populations with a low TB risk only.     

Interferon-gamma release assays for the tuberculosis serial testing of health care workers: a systematic review

Background

Interferon-gamma release assays (IGRAs) are increasingly used in the tuberculosis (TB) screening of health care workers (HCWs). However, comparatively high rates of conversions and reversion as well as growing evidence of substantial within-subject variability of interferon-gamma responses complicate their interpretation in the serial testing of HCWs.

Methods

We conducted a systematic review on the repeat use of the two commercial IGRAs, the QuantiFERON-TB Gold or In-Tube version (QFT) and the T-SPOT.TB (T-SPOT), in the serial testing and its with-subject variability among HCWs in order to provide guidance on how to interpret serial testing results in the context of the periodic screening of subjects with an increased occupational risk of latent TB infection (LTBI) in countries with low and intermediate TB incidence rates. The Medline, Embase, and Cochrane databases were searched without restrictions. Retrieved articles were complemented by additional hand searched records. Only studies that used commercial IGRAs among HCWs apart from contact and outbreak investigations and those fulfilling further predefined criteria were included.

Results

Overall, 20 studies, five using the T-SPOT and 19 using the QFT assay, were included. Fifteen studies met eligibility criteria for serial testing and five studies for within-subject variability. Irrespective of TB incidence rates in the study??s country of origin, reversion rates were consistently higher than conversion rates (range 22?C71% vs. 1?C14%). Subjects with baseline results around the diagnostic threshold were more likely to show inconsistent results on retesting. The within-subject variability of interferon-gamma responses was considerable across all studies systematically assessing it.

Conclusions

On the basis of reviewed studies we advocate using a borderline zone from 0.2?C0.7?IU/ml for the interpretation of repeat QFT results in the routine screening of HCWs with an increased LTBI risk. Subjects with QFT results within this borderline zone, with suspected fresh infection, and those who are considered for preventive chemotherapy should be retested with the QFT within a period of about four weeks before preventive chemotherapy is recommended. However, the available data regarding the use of the T-SPOT in the serial testing of HCWs is remarkably limited and warrants further research.     

Outbreak of Pulmonary Tuberculosis in a Chinese High School, 2009–2010

Background

In February 2009, a high school student was diagnosed with sputum-smear positive pulmonary tuberculosis (TB). One year later, 2 other students in the same grade developed sputum-smear positive TB.

Methods

We used tuberculin skin testing (TST), chest radiography, sputum smear, and symptomatology for case identification. We defined latent TB infection (LTBI) as a TST induration of 15 mm or larger, probable TB as a chest radiograph indicative of TB plus productive cough/hemoptysis for at least 2 weeks or TST induration of 15 mm or larger, and confirmed TB as 2 or more positive sputum smears or 1 positive sputum smear plus a chest radiograph indicative of TB.

Results

Of students in the same grade as the primary case-student, 26% (122/476) had LTBI and 4.8% (23/476) had probable/confirmed TB. Of teachers, 43% (18/42) had LTBI and none had probable/confirmed TB. Sharing a classroom with the primary case-student increased risk for LTBI (rate ratio = 2.5; 95% CI: 1.9–3.4) and probable/confirmed TB (rate ratio = 17, 95% CI: 7.8–39). Of students with LTBI in February 2009 who refused prophylaxis, 50% (11/22) had probable/confirmed TB in April 2010.

Conclusions

This TB outbreak was likely started by delayed diagnosis of TB in the case-student and was facilitated by lack of post-exposure chemoprophylaxis. Post-exposure prophylaxis is strongly recommended for all TST-positive students.Key words: epidemiology, outbreak, students, tuberculosis     

Mycobacterium Tuberculosis Infection,Immigration Status,and Diagnostic Discordance: A Comparison of Tuberculin Skin Test and QuantiFERON?-TB Gold In-Tube Test Among Immigrants to the U.S.

Objective

We used a recent source of nationally representative population data on tuberculosis (TB) infection to characterize concordance between the tuberculin skin test (TST) and the QuantiFERON^®-TB Gold In-Tube (QFT-GIT) blood test for immigrants in the United States.

Methods

We used TB screening data from the 2011–2012 National Health and Nutrition Examination Survey to examine concordance between the TST and QFT-GIT—an interferon-gamma release assay (IGRA) blood test—for 7,097 U.S. natives, naturalized citizens, and noncitizens.

Results

Consistent with prior findings, one in five immigrants in the survey was identified with latent TB infection (LTBI), a rate 14 times higher than for U.S. natives. We also found higher rates of discordant TST/IGRA results among immigrants than among U.S. natives. Unadjusted discordance between TST and IGRA was 3% among U.S. natives (weighted N=5,684,274 of 191,179,213) but ranged up to 19% for noncitizens (weighted N=3,722,960 of 19,377,147). Adjusting for age, sex, and race/ethnicity, noncitizens had more than nine times the odds of having a positive TST result but negative QFT-GIT result compared with U.S. natives.

Conclusions

Our findings suggest that whether and how either of these tests should be deployed is highly context sensitive. Significant discordance in test results when used among immigrants raises the possibility of missed opportunities for harm reduction in this already at-risk population. However, we found little distinction between the tests in terms of diagnostic outcome when used in a U.S. native population, suggesting little benefit to the adoption and use of the QFT-GIT test in place of TST on the basis of test performance alone for this population.Although systematic public health efforts during the last 60 years have produced dramatic reductions in domestic tuberculosis (TB) incidence, prevalence, and fatalities, TB remains a major public health threat to global populations, with serious health and economic consequences, especially TB that is resistant to treatment.^1–6 One focus of public health efforts to control TB in the United States has been to screen immigrants for active TB by collecting a medical history, conducting a physical examination, and performing a chest radiography for all visa applicants aged ≥15 years.^7–9 Still, many immigrants, especially from high-burden regions, enter the United States in apparent health but carrying latent TB infection (LTBI) from some prior TB exposure. As a result, nearly two-thirds of new TB cases in the United States occur among the foreign-born.¹ LTBI may not be promptly identified and treated for immigrants in part because of well-documented barriers to health-care access for this population and also because of the complexity of diagnosing LTBI and effectively evaluating the risks and benefits of its treatment.¹⁰The current mainstay of TB risk evaluation—the tuberculin skin test (TST)—has many limitations, including a requirement for two health worker visits up to 72 hours apart, inability to distinguish LTBI from active TB, subjective interpretation of test results, and the test being subject to confounding by other infections or bacille Calmette-Guérin (BCG) immunization.^7,8,11–13 A new generation of diagnostic tests, Interferon Gamma-Release Assays (IGRAs), shows promise as an effective screening method for LTBI in part because these tests may have fewer limitations than TSTs; they have reduced confounding by immune response and less subjectivity in interpreting results, and are based on more specific markers.^11,12 The IGRA requires only one health-care visit during which a blood sample is drawn. Laboratory results for the IGRA can be available within 24 hours.¹³However, much remains unknown about the efficacy of IGRAs relative to TSTs, and without a gold standard diagnostic, the Centers for Disease Control and Prevention (CDC) recommends screening for TB using either the TST or IGRA, but not both.¹³ TSTs cost less than IGRAs, which may be an important consideration for public health departments.^14–18 Other disadvantages of IGRAs are that blood samples must be collected, transported to a laboratory, and processed shortly after collection.¹³ More importantly, growing evidence suggests that IGRA and TST results may be widely discordant when used among immigrants or other special groups relative to a U.S. native or more generalized U.S. population. One study of 279 immigrants to Italy found only a 70.9% concordance between these tests.¹⁹ A separate study of 132 U.S. visa applicants from Vietnam with culture-confirmed TB found a lack of concordance for 16 tested applicants.²⁰ A study of 604 newly arrived refugees in Decatur, Georgia, documented that one in four had discordant test results between TST and QuantiFERON^®-TB Gold In-Tube (QFT-GIT, QIAGEN, Hilden, Germany).²¹ This lack of concordance—in combination with CDC recommendations against using both tests for TB screening—may result in substantial numbers of immigrants receiving inaccurate test results when being initially screened for TB.To our knowledge, no nationally representative study of concordance between the TST and IGRA for immigrants in the United States has been conducted. We used a well-established source of nationally representative population data on TB infection to characterize concordance between the TST and the IGRA for immigrants in the United States.     

Results of five-year systematic screening for latent tuberculosis infection in healthcare workers in Portugal

Introduction  

The risk of tuberculosis (TB) in healthcare workers (HCWs) is related to its incidence in the general population, and increased by the specific risk as a professional group. The prevalence of latent tuberculosis infection (LTBI) in HCWs in Portugal using the tuberculin skin test (TST) and the interferon-γ release assays (IGRA) was analyzed over a five-year period.     

Eliminating Tuberculosis One Neighborhood at a Time

Objectives. We evaluated a strategy for preventing tuberculosis (TB) in communities most affected by it.Methods. In 1996, we mapped reported TB cases (1985–1995) and positive tuberculin skin test (TST) reactors (1993–1995) in Smith County, Texas. We delineated the 2 largest, densest clusters, identifying 2 highest-incidence neighborhoods (180 square blocks, 3153 residents). After extensive community preparation, trained health care workers went door-to-door offering TST to all residents unless contraindicated. TST-positive individuals were escorted to a mobile clinic for radiography, clinical evaluation, and isoniazid preventive treatment (IPT) as indicated. To assess long-term impact, we mapped all TB cases in Smith County during the equivalent time period after the project.Results. Of 2258 eligible individuals, 1291 (57.1%) were tested, 229 (17.7%) were TST positive, and 147 were treated. From 1996 to 2006, there were no TB cases in either project neighborhood, in contrast with the preintervention decade and the continued occurrence of TB in the rest of Smith County.Conclusions. Targeting high-incidence neighborhoods for active, community-based screening and IPT may hasten TB elimination in the United States.According to a 1999–2000 tuberculin skin test (TST) survey, an estimated 4.2% of the US population—approximately 11 million people—had latent Mycobacterium tuberculosis infection (LTBI).1 Reactivation of LTBI accounts for an estimated 70% of incident tuberculosis (TB) disease in the United States.2,3 Eliminating TB in the United States will require preventing these cases.Treating LTBI with 6 to 12 months of isoniazid can substantially reduce TB incidence.2,4–7 But how can 11 million individuals be identified and treated without testing the entire population? Testing for LTBI in the general population is not recommended because the predictive value of a positive TST under conditions of low prevalence is poor, and skin testing should be limited to persons at high risk.2,8,9 Moreover, active screening and preventive treatment programs typically fail because of high rates of nonparticipation and attrition at each step of the process. The keys to active, community-based screening and preventive treatment would be to target high-risk populations with an efficient strategy, maximize participation, and minimize losses to follow-up so that the entire process becomes cost-effective.Many local health departments map cases of communicable diseases in their communities, displaying wall-mounted maps with color-coded pins indicating each case. Dense clusters of pins identify the hardest-hit neighborhoods. The modern version of this venerable practice involves use of a computerized geographic information system (GIS). We hypothesized that this information could identify neighborhoods at high risk of TB. If TB concentrates in specific neighborhoods, persisting over many years, then cases will likely continue occurring in these same neighborhoods. Targeting these neighborhoods with screening and prevention programs should prevent future TB cases. Using a GIS, we identified 2 high-risk neighborhoods in Smith County, Texas, and conducted a door-to-door screening and preventive treatment project. Ten years later, we assessed the impact of this strategy by comparing TB incidence in the target neighborhoods before and after the project with TB incidence in the rest of the county.     

Transnational Record Linkage for Tuberculosis Surveillance and Program Evaluation

Objective

Pre-immigration tuberculosis (TB) screening, followed by post-arrival rescreening during the first year, is critical to reducing TB among foreign-born people in the United States. However, existing U.S. public health surveillance is inadequate to monitor TB among immigrants during subsequent years. We developed and tested a novel method for ascertaining post-U.S.-arrival TB outcomes among high-TB-risk immigrant cohorts to improve surveillance.

Methods

We used a probabilistic record linkage program to link pre-immigration screening records from U.S.-bound immigrants from the Philippines (n=422,593) and Vietnam (n=214,401) with the California TB registry during 2000–2010. We estimated sensitivity using Monte Carlo simulations to account for uncertainty in key inputs. Specificity was evaluated by using a time-stratified approach, which defined false-positives as TB records linked to pre-immigration screening records dated after the person had arrived in the United States.

Results

TB was reported in 4,382 and 2,830 people born in the Philippines and Vietnam, respectively, in California during the study period. Of these TB cases, records for 973 and 452 cases of people born in the Philippines and Vietnam, respectively, were linked to pre-immigration screening records. Sensitivity and specificity of linkage were 89% (90% credible interval [CrI] 83, 97) and 100%, respectively, for the Philippines, and 90% (90% CrI 83, 98) and 99.9%, respectively, for Vietnam.

Conclusion

Electronic linkage of pre-immigration screening records to a domestic TB registry was feasible, sensitive, and highly specific in two high-priority immigrant cohorts. Transnational record linkage can be used for program evaluation and routine monitoring of post-U.S.-arrival TB risk among immigrants, but requires interagency data sharing and collaboration.Tuberculosis (TB) among foreign-born people is the central challenge to TB elimination in the United States. In 2014, the TB rate among foreign-born people was nearly 13.4 times higher than the TB rate among U.S.-born people, and foreign-born people accounted for 67% of reported TB.¹ Most TB among foreign-born people results from latent TB infection (LTBI) acquired in immigrants'' home countries,^2,3 and rates are highest among new entrants.^2,4–7 TB detection and prevention among new immigrants and refugees, therefore, are important public health priorities.⁸Each year, approximately 450,000 refugees and immigrants undergo required pre-immigration TB screening at designated overseas sites, according to Centers for Disease Control and Prevention (CDC) guidelines.^9–11 In 2007, pre-immigration screening guidelines changed substantially. The pre-2007 screening, which included medical history, physical examination, and chest radiograph for all adults >14 years of age, with additional acid-fast bacilli sputum smears for those with abnormal radiographs, was enhanced to include mycobacterial cultures and directly observed treatment of diagnosed TB. For children 2–14 years of age, the new guidelines implemented universal testing for LTBI with either tuberculin skin test (TST) or an interferon-gamma release assay (IGRA). Those with positive tests receive a chest radiograph. Both adults with abnormal chest radiographs and children with positive LTBI results are asked to follow up for post-arrival evaluation by local U.S. public health agencies, and those with LTBI are recommended for treatment.Improved surveillance is needed to assess the impact of these changes in pre-immigration TB screening and post-arrival LTBI treatment on TB incidence in the United States. Currently, TB reports are collected in domestic TB case registries maintained by state TB programs in the form of a Report of Verified Case of TB and reported to CDC after removal of personal identifying information. Immigration status was not ascertained until 2009, when self-reported visa status at first entry into the United States was added to the Report of Verified Case of TB form. However, data on this variable are incomplete because some patients do not recall initial immigration status, and some health jurisdictions have policies that restrict asking patients about their immigration status. Additionally, immigration status for potential subsequent entries into the United States is not captured. Therefore, TB risk among immigrants who have undergone pre-immigration screening cannot be quantified separately from the risk among the approximately 160 million foreign-born students, business travelers, and tourists admitted to the United States annually.¹²We hypothesized that overseas pre-immigration screening records could be linked with state-level domestic TB case registries, even without a unique identifier. A similar strategy of using existing public health surveillance to ascertain the occurrence of TB in a defined cohort of individuals was used in the landmark Comstock studies in the 1960–1970s. In these studies, baseline TST measurements were collected among 82,000 Puerto Rican children and 800,000 U.S. naval recruits and later linked to TB case reports, hospital records, and death certificates to describe the predictive value of TST for development of TB.^13,14 Electronic linkage with TB case registries would provide a cost-effective method of conducting similar studies in the modern era.As a preliminary step toward designing a surveillance system for monitoring TB trends in immigrants and evaluating interventions, we developed a method for linking pre-immigration screening records with subsequent TB case reports in California. To determine if this method performs similarly in different immigrant groups, we evaluated feasibility and accuracy in large cohorts of Philippines- and Vietnam-born immigrants, who account for 34% of TB in the foreign-born population in California.¹⁵     

Detecting Mycobacterium tuberculosis Infection in Children Migrating to Australia

In 2015, Australia updated premigration screening for tuberculosis (TB) disease in children 2–10 years of age to include testing for infection with Mycobacterium tuberculosis and enable detection of latent TB infection (LTBI). We analyzed TB screening results in children <15 years of age during November 2015–June 2017. We found 45,060 child applicants were tested with interferon-gamma release assay (IGRA) (57.7% of tests) or tuberculin skin test (TST) (42.3% of tests). A total of 21 cases of TB were diagnosed: 4 without IGRA or TST, 10 with positive IGRA or TST, and 7 with negative results. LTBI was detected in 3.3% (1,473/44,709) of children, for 30 applicants screened per LTBI case detected. LTBI-associated factors included increasing age, TB contact, origin from a higher TB prevalence region, and testing by TST. Detection of TB and LTBI benefit children, but the updated screening program’s effect on TB in Australia is likely to be limited.     

Occupational health policies and practices related to tuberculosis in health care workers in KwaZulu-Natal,South Africa

Setting:

Three district hospitals in KwaZulu-Natal, South Africa, with specialized drug-resistant tuberculosis (TB) wards.

Objective:

To increase understanding of the implementation of occupational health (OH) and infection control (IC) guidelines for the prevention and control of TB among health care workers (HCWs).

Design:

An operational cross-sectional study conducted between July and September 2011, consisting of interviews with OH and IC nurses and chart review of OH medical records.

Results:

Although general national and provincial OH policies are in place, no specific OH policies exist for hospital settings. Two of three hospitals had a full-time OH nurse and all had a full-time IC nurse. All hospitals offered TB symptom screening; however, only 19% of HCWs were screened in 2010. TB incidence among HCWs was 1958 per 100 000 population in 2010. All hospitals offered HIV counseling and testing; however, only 22% of staff were tested across sites. Two hospitals offered isoniazid preventive therapy to HIV-positive staff and reassigned these staff to low TB risk areas.

Conclusions:

While OH policies and procedures are in place, implementation of these policies and procedures is inconsistent. This potentially places HCWs at risk of acquiring TB. These findings support the need for strengthening OH and IC services to prevent TB.     

Hepatitis B and C infection: Is it a problem in Polish healthcare workers?

Objectives

Hepatitis B (HBV) and C viruses (HCV) are among the most frequent blood borne pathogens. According to WHO, 5% of healthcare workers (in central Europe), are exposed to at least one sharps injury contaminated with HBV per year, 1,7% — contaminated with HCV.

Aims

The aims of the study were to determine prevalence of HCV and HBV infections, vaccination efficacy against hepatitis B and usefulness of alanine aminotransferase (ALT) testing in prophylactic examinations in healthcare workers (HCWs).

Material and Methods

In a group of 520 healthcare workers, a survey, laboratory and serologic tests such as ALT, HBsAg, anti-HBs, anti-HBcT and anti-HCV were carried out.

Results

The study revealed a low rate of workers with presence of HBsAg and anti-HCV (1,2% and 0,8% respectively). Anti-HBcT was found in 99 subjects (19%) without a significant association with experiencing an occupational percutaneous injury. Being vaccinated against HBV was declared by 90% of the subjects. There was no relationship between ALT level rise and positive HBsAg, anti-HCV and anti-HBcT tests.

Conclusion

A seroprevalence of HBV and HCV markers in HCWs found in the study is low and similar to the one found in general population. Current or past hepatitis B infections were independent of needle stick injuries. Vaccination against HBV coverage, although found to be high, should improve to 100%. Occupational prophylactic medical examinations found performing ALT test (obligatory in Poland for HCWs) not helpful. It seems that determination of anti-HBcT and anti-HCV status would be essential in pre-employment medical examinations.     

Risk factors for Mycobacterium tuberculosis infection among children in Greenland

Objective

To examine the risk factors for Mycobacterium tuberculosis infection (MTI) among Greenlandic children for the purpose of identifying those at highest risk of infection.

Methods

Between 2005 and 2007, 1797 Greenlandic schoolchildren in five different areas were tested for MTI with an interferon gamma release assay (IGRA) and a tuberculin skin test (TST). Parents or guardians were surveyed using a standardized self-administered questionnaire to obtain data on crowding in the household, parents’ educational level and the child’s health status. Demographic data for each child – i.e. parents’ place of birth, number of siblings, distance between siblings (next younger and next older), birth order and mother’s age when the child was born – were also extracted from a public registry. Logistic regression was used to check for associations between these variables and MTI, and all results were expressed as odds ratios (ORs) and 95% confidence intervals (CIs). Children were considered to have MTI if they tested positive on both the IGRA assay and the TST.

Findings

The overall prevalence of MTI was 8.5% (152/1797). MTI was diagnosed in 26.7% of the children with a known TB contact, as opposed to 6.4% of the children without such contact. Overall, the MTI rate was higher among Inuit children (OR: 4.22; 95% CI: 1.55–11.5) and among children born less than one year after the birth of the next older sibling (OR: 2.48; 95% CI: 1.33–4.63). Self-reported TB contact modified the profile to include household crowding and low mother’s education. Children who had an older MTI-positive sibling were much more likely to test positive for MTI themselves (OR: 14.2; 95% CI: 5.75–35.0) than children without an infected older sibling.

Conclusion

Ethnicity, sibling relations, number of household residents and maternal level of education are factors associated with the risk of TB infection among children in Greenland. The strong household clustering of MTI suggests that family sources of exposure are important.     

Economic evaluations of non-communicable disease interventions in developing countries: a critical review of the evidence base

Background

Public-private partnerships (PPP) could be effective in scaling up services. We estimated cost and cost-effectiveness of different PPP arrangements in the provision of tuberculosis (TB) treatment, and the financing required for the different models from the perspective of the provincial TB programme, provider, and the patient.

Methods

Two different models of TB provider partnerships are evaluated, relative to sole public provision: public-private workplace (PWP) and public-private non-government (PNP). Cost and effectiveness data were collected at six sites providing directly observed treatment (DOT). Effectiveness for a 12-month cohort of new sputum positive patients was measured using cure and treatment success rates. Provider and patient costs were estimated, and analysed according to sources of financing. Cost-effectiveness is estimated from the perspective of the provider, patient and society in terms of the cost per TB case cured and cost per case successfully treated.

Results

Cost per case cured was significantly lower in PNP (US $354–446), and comparable between PWP (US $788–979) and public sites (US $700–1000). PPP models could significantly reduce costs to the patient by 64–100%. Relative to pure public sector provision and financing, expansion of PPPs could reduce government financing required per TB patient treated from $609–690 to $130–139 in PNP and $36–46 in PWP.

Conclusion

There is a strong economic case for expanding PPP in TB treatment and potentially for other types of health services. Where PPPs are tailored to target groups and supported by the public sector, scaling up of effective services could occur at much lower cost than solely relying on public sector models.     

Experiences and perceptions of online continuing professional development among clinicians in sub-Saharan Africa

Background

Limitations in healthcare worker (HCW) capacity compound the burden of dual TB and HIV epidemics in sub-Saharan Africa. To fill gaps in knowledge and skills, effective continuing profession development (CPD) initiatives are needed to support practicing HCWs reach high standards of care. e-learning opportunities can bring expert knowledge to HCWs in the field and provide a flexible learning option adaptable to local settings. Few studies provide insight into HCW experiences with online CPD in the developing country context.

Methods

An online survey using both close-ended and free response was conducted to HCWs in sub-Saharan Africa who completed the University of Washington (UW) School of Medicine online graduate course, “Clinical Management of HIV.” Associations between respondent characteristics (age, gender, rural/urban, job title) and learning preferences, course barriers, and facilitators with an emphasis on online courses were examined using chi-square. Covariates significant at the p?<?0.05 were analyzed using multivariable logistic regression. Responses to open-ended comments were analyzed using simplified grounded theory.

Results

Of 2,299 former students, 464 (20%) HCWs completed surveys from 13 countries: about half were women. Physicians (33%), nurses (27%), and clinical officers (30%) responded mostly from urban areas (67%) and public institutions (69%). Sixty-two percent accessed the online course from work, noting that slow (55%) or limited (41%) internet as well as lack of time (53%) were barriers to course completion. Women (p?<?0.001) and HCWs under age 40 (p?=?0.007) were more likely to prefer learning through mentorship than men or older HCWs. Respondents favored group discussion (46%), case studies (42%), and self-paced Internet/computer-based learning (39%) and clinical mentorship (37%) when asked to choose 3 preferred learning modalities. Free-response comments offered additional positive insights into the appeal of online courses by noting the knowledge gains, the flexibility of format, a desire for recognition of course completion, and a request for additional online coursework.

Conclusions

Online CPD opportunities were accepted across a diverse group of HCWs from sub-Saharan Africa and should be expanded to provide more flexible opportunities for self-initiated learning; however, these need to be responsive to the limited resources of those who seek these courses.

     

Postarrival Tuberculosis Screening of High-Risk Immigrants at a Local Health Department

Objectives. We sought to characterize postimmigration tuberculosis (TB) care for Class B immigrants and refugees at the Baltimore City Health Department TB program (BCHD), and to determine the proportion of immigrants with active TB or latent TB infection (LTBI) in this high-risk population.Methods. We conducted a retrospective chart review of Class B immigrants and refugees who reported to the BCHD for postimmigration TB evaluation from 2010 to 2012.Results. We reviewed the clinical records of 153 Class B immigrants; 4% were diagnosed with active TB and 53% were diagnosed with LTBI. Fifty percent of active TB cases were culture positive, and 67% were asymptomatic; 100% received and completed active TB therapy at the BCHD. Among those diagnosed with LTBI, 87% initiated LTBI therapy and 91% completed treatment.Conclusions. The high prevalence of active TB and LTBI found among Class B immigrants underscore the importance for postarrival TB screening. The absence of reported symptoms among the majority of active cases identified during this study suggest that reliance on symptom-based screening protocols to prompt sputa testing may be inadequate for identifying active TB among this high-risk group.Efforts by local health departments to screen recent immigrants for tuberculosis (TB) are an important component of broader TB control goals. Foreign-born individuals represent a significant source of new cases of active TB reported in the United States. In 2012, the incidence of TB was 11.5 times as great among foreign-born individuals in the United States than it was for individuals born in the United States.1 It has been estimated by the US Centers for Disease Control and Prevention (CDC) that 4 out of 5 active TB cases among foreign-born persons is attributable to reactivation of TB that was likely acquired prior to arrival in the United States.2To reduce the chances that TB will be introduced from abroad, US policy requires that individuals applying to immigrate or be relocated to the United States must undergo a prearrival medical exam that includes TB screening. US Department of State–appointed panel physicians, according to technical instructions developed by the conduct these exams overseas. In 2007, CDC published new technical instructions that required additional screening measures, including sputa cultures when sputa testing is indicated and drug-susceptibility testing for positive isolates.3Under the current technical instructions, individuals with evidence of untreated, active, contagious TB are considered to have a Class A condition.4 Only those Class A applicants who receive a medical waiver are allowed to enter the United States; all other Class A applicants must demonstrate that they have undergone successful treatment of TB under directly observed therapy before they can reapply to immigrate to the United States. Individuals with some radiographic evidence of TB (including extrapulmonary TB that is not laryngeal or pleural), but negative smears and cultures, are designated as Class B1, pulmonary, or Class B1, extrapulmonary. Individuals who have a positive tuberculin skin test (TST; ≥ 5 mm if individual is a contact of known TB case, and ≥ 10 mm for all others) or Interferon-γ Release Assay (IGRA), but no other signs of TB are classified as Class B2, Latent TB Infection (LTBI) evaluation. Under the current technical instructions, the majority of immigrants who receive a B2 classification are children, as only applicants 2 to 14 years of age who are screened in a country where the World Health Organization-estimated TB incidence is 20 per 100 000 persons or greater receive TST or IGRA testing as part of initial screening. Recent contacts of a known TB case (usually, contacts of individuals who have received an A classification) are designated as Class B3, contact evaluation. All TB Class B immigrants are allowed entry to the country, but, because they are considered to be at high risk for developing TB, they are instructed to report to health departments or private clinicians for follow-up screening and, if indicated, treatment within 30 days of arrival.The Baltimore City Health Department (BCHD) TB program provides clinical evaluation and care services to Class B immigrants that settled within the city. As of 2007, the guidelines for screening Class B immigrants as published by the State of Maryland have required sputum testing for only those Class B immigrants who, upon evaluation, were found to have a productive cough.5 In 2012, BCHD modified its protocol for evaluating Class B immigrants, to consider sputum testing of all Class B1 immigrants, regardless of whether they had TB symptoms or not.Though US programs are designed to identify and prioritize for follow-up screening new immigrants who may be at high risk for developing TB upon arrival in the United States, few studies have been published describing postimmigration efforts to screen and treat newly arrived immigrants.6–10 In this light, we performed a retrospective chart review of Class B immigrants referred to the BCHD for TB evaluation between 2010 to 2012 to describe how Class B immigrants were screened in practice, and we compared these results with existing local protocols and national recommendations for Class B immigrant screening.     

Understanding the Burden of Tuberculosis Among American Indians/Alaska Natives in the U.S.: A Validation Study

Objective

We validated cases of active tuberculosis (TB) recorded in the Indian Health Service (IHS) National Patient Information Reporting System (NPIRS) and evaluated the completeness of TB case reporting from IHS facilities to state health departments.

Methods

We reviewed the medical records of American Indian/Alaska Native (AI/AN) patients at IHS health facilities who were classified as having active TB using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic codes from 2006 to 2009 for clinical and laboratory evidence of TB disease. Individuals were reclassified as having active TB disease; recent latent TB infection (LTBI); past positive tuberculin skin test (TST) only; or as having no evidence of TB, LTBI, or a past positive TST. We compared validated active TB cases with corresponding state records to determine if they were reported.

Results

The study included 596 patients with active TB as per ICD-9-CM codes. Based on chart review, 111 (18.6%) had active TB; 156 (26.2%) had LTBI; 104 (17.4%) had a past positive TST; and 221 (37.1%) had no evidence of TB disease, LTBI, or a past positive TST. Of the 111 confirmed cases of active TB, 89 (80.2%) resided in participating states; 81 of 89 (91.2%) were verified as reported TB cases.

Conclusions

ICD-9-CM codes for active TB disease in the IHS NPIRS do not accurately reflect the burden of TB among AI/ANs. Most confirmed active TB cases in the IHS health system were reported to the state; the national TB surveillance system may accurately represent the burden of TB in the AI/AN population.Tuberculosis (TB) is a bacterial infection caused by Mycobacterium tuberculosis (M. tuberculosis) complex. Treatment for active TB disease requires months of combination drug therapy. Left untreated, TB can result in substantial morbidity and occasionally death. Although the number of TB cases in the United States has steadily declined during the past two decades, TB remains a major health concern within many subgroups, including American Indians/Alaska Natives (AI/ANs). The TB case rate among AI/ANs is estimated at 5.6 per 100,000 population, notably higher than the national average of 3.4 cases per 100,000 population.¹Surveillance of active TB disease is an important component of monitoring and controlling the spread of TB. Currently, annual rates of TB in the U.S. are calculated by the Centers for Disease Control and Prevention (CDC) National Tuberculosis Surveillance System (NTSS).¹ The NTSS is an electronic database that relies on the collaboration of state and local health departments; each person diagnosed with TB disease is verified as an incident case of TB and reported using a standard TB case form. The criteria for TB disease surveillance are based on a laboratory case definition, clinical case definition, or provider diagnosis.^1,2 The laboratory case definition requires isolation of M. tuberculosis complex in culture or detection of M. tuberculosis complex nucleic acids by amplification testing or demonstration of acid-fast bacilli in a clinical specimen when a culture cannot be obtained. The clinical case definition requires (1) a positive tuberculin skin test (TST), (2) signs and symptoms compatible with TB, (3) treatment with at least two anti-TB medications, and (4) a completed diagnostic evaluation. A provider diagnosis is used when the clinical presentation is consistent with TB but the criteria to meet laboratory or clinical case definitions are not met.The Indian Health Service (IHS), an agency of the U.S. Department of Health and Human Services, provides comprehensive health-care services through IHS, Tribal, and Urban Indian facilities (collectively referred to hereafter as IHS) to eligible AI/AN people who are members of 566 federally recognized Tribes. IHS provides care for approximately 2.1 million (62%) of the nation''s estimated 3.4 million AI/ANs.³ The IHS maintains a national database, the National Patient Information Reporting System (NPIRS).⁴ Within NPIRS, diseases and conditions are coded according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM).⁵ In addition, IHS is in the process of implementing an electronic health record (EHR) system.⁶ Electronic data collected by IHS have the potential to serve as a resource to better understand the burden and monitor trends of TB disease within the AI/AN population; yet, the accuracy of NPIRS for identifying people with TB disease has not been previously established. Several previous studies in other U.S. populations have cited wide variability (0%–77%) in the positive predictive value (PPV) of ICD-9-CM diagnostic codes for active TB disease.^7–13CDC provides guidance for IHS providers to report all nationally notifiable diseases, including TB, to local and state authorites.^1,2 However, there are no explicit mechanisms for IHS to report cases of TB directly to the NTSS, and the extent to which IHS facilities collaborate with local authorities on case reporting is not well understood.We validated active cases of TB disease within the AI/AN population by reviewing the medical charts of individuals assigned an active TB disease ICD-9-CM code in the inpatient and outpatient NPIRS visit data from 2006 to 2009 to determine the completeness of reporting TB disease by examining whether validated TB cases from IHS facilities were reported to state health departments.     

Risk factors associated with disease progression and mortality in chronic kidney disease of uncertain etiology: a cohort study in Medawachchiya, Sri Lanka

Background

The alarming rise in the prevalence of chronic kidney disease of uncertain etiology (CKDu) among the low socioeconomic farming community in the North Central Province of Sri Lanka has been recognized as an emerging public health issue in the country.

Methods

This study sought to determine the possible factors associated with the progression and mortality of CKDu. The study utilized a single-center cohort registered in 2003 and followed up until 2009 in a regional clinic in the endemic region, and used a Cox proportional hazards model.

Results

We repeatedly found an association between disease progression and hypertension. Men were at higher risk of CKDu than women. A significant proportion of the patients in this cohort were underweight, which emphasized the need for future studies on the nutritional status of these patients.

Conclusions

Compared with findings in western countries and other regions of Asia, we identified hypertension as a major risk factor for progression of CKDu in this cohort.     

Health-related quality of life among pulmonary tuberculosis patients in Pakistan

Purpose

Health-related quality of life (HRQoL) of pulmonary TB patients has not been assessed in Pakistan. We assessed self-reported HRQoL of pulmonary TB patients in Karachi, Pakistan utilizing the EQ-5D and EQ-VAS prior to, during, and after completion of TB treatment.

Methods

We enrolled 226 pulmonary TB patients in a longitudinal cohort study. Health-utility scores were estimated by the EQ-5D five dimensions and the EQ-Visual Analogue Scale (VAS) at baseline (month 0) and each monthly follow-up visit until treatment completion at month 6. Repeated-measures ANOVA was used to investigate effect of time into treatment on EQ-5D and EQ-VAS scores.

Results

EQ-5D health utility and EQ-VAS scores increase with treatment progression. For the enrolled TB patients, the mean EQ-5D utility scores more than doubled from 0.43 to 0.88, p?<?.001, effect size η²?=?0.40 from treatment initiation to treatment completion.

Conclusion

Perceived HRQoL of TB patients improves with treatment progression. This can inform targeted treatment plans as well as TB policy and funding for high-burden countries.

     

Screening for delirium within the interrai acute care assessment system

Objectives

To develop and validate a screening strategy for delirium within the inter RAI Acute Care comprehensive assessment system.

Design

Prospective validation cohort study.

Setting

Acute general medical wards in two acute care metropolitan hospitals in Brisbane, Australia.

Participants

Two hundreds thirty-nine subjects with and without delirium, aged 70 and older.

Measurements

Trained research nurses assessed subjects within 36 hours of hospital admission using the inter-RAI acute care (AC) system which includes four observational delirium items: Acute change mental status from baseline (ACMS), mental function varies over the course of the day (MFV), episode of disorganised speech (EDS), and easily distracted (ED). Geriatricians assessed subjects face to face within 4 hours of nurses?? assessment using the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) criteria and clinical judgement to determine delirium presence. Based on the performance of each delirium feature and to achieve highest predictive accuracy, a combination algorithm of either ACMS or MFV was developed and compared with the reference standard diagnosis determined by geriatricians.

Results

Geriatricians diagnosed delirium in 52 of 239 (21.7%) subjects aged 70?C102 years. The area under the receiver operator characteristics (AUC) for interRAI-AC delirium screener algorithm was 0.87 (95% CI; 0.80, 0.93), sensitivity 82%, specificity 91%, positive and negative predictive value of 0.72% and 95%, and likelihood ratio of 9.6 achieving the highest predictive accuracy of all possible combination of 4 delirium features. Underlying pre-morbid cognitive impairment did not undermine validity of the screening strategy, AUC 0.85 (95% CI; 0.74,0.95), sensitivity 90% and specificity 69%.

Conclusion

The interRAI AC delirium screening strategy is a valid measure of delirium in older subjects in acute medical wards.     

In-hospital contact investigation among health care workers after exposure to pulmonary tuberculosis in an intermediate tuberculosis prevalence area: A prospective study

We carried out in-hospital contact investigations of patients with pulmonary tuberculosis and analyzed the prevalence of latent tuberculosis infection (LTBI) among health care workers (HCWs) after TB exposure. A prospective study was conducted of 872 HCWs who were exposed to 55 index cases diagnosed with active pulmonary TB. HCWs after TB exposure were evaluated both TST and chest X-ray at the time of enrollment and 12 weeks after exposure; 625 HCWs (71.6%) underwent both initial assessments; 41 HCWs (6.6%) had a positive TST result. After 12 weeks, 71.1% of HCWs with initial negative TST (n = 415) underwent a second assessment. Ten HCWs had TST conversion. One HCW (0.2%) developed active pulmonary TB. In multivariable analysis, age over 30 years was associated with TST conversion (p = .02). Point prevalence of latent TB was 6.6%, and incidence of LTBI was estimated as 2.4 per 100 HCWs. Strict infection control measures should be emphasized in intermediate TB-burden, BCG-vaccinated countries, especially in HCWs with high risk for TB exposure.