Yield of contact tracing from pediatric tuberculosis index cases in Gaborone, Botswana

Clinical standards for drug-susceptible TB in children and adolescents

BACKGROUND: These clinical standards aim to provide guidance for diagnosis, treatment, and management of drug-susceptible TB in children and adolescents.METHODS: Fifty-two global experts in paediatric TB participated in a Delphi consensus process. After eight rounds of revisions, 51/52 (98%) participants endorsed the final document.RESULTS: Eight standards were identified: Standard 1, Age and developmental stage are critical considerations in the assessment and management of TB; Standard 2, Children and adolescents with symptoms and signs of TB disease should undergo prompt evaluation, and diagnosis and treatment initiation should not depend on microbiological confirmation; Standard 3, Treatment initiation is particularly urgent in children and adolescents with presumptive TB meningitis and disseminated (miliary) TB; Standard 4, Children and adolescents should be treated with an appropriate weight-based regimen; Standard 5, Treating TB infection (TBI) is important to prevent disease; Standard 6, Children and adolescents should receive home-based/community-based treatment support whenever possible; Standard 7, Children, adolescents, and their families should be provided age-appropriate support to optimise engagement in care and clinical outcomes; and Standard 8, Case reporting and contact tracing should be conducted for each child and adolescent.CONCLUSION: These consensus-based clinical standards, which should be adapted to local contexts, will improve the care of children and adolescents affected by TB.

Tuberculosis contact investigation in African Portuguese-speaking countries at End TB Strategy era: a scoping review

OBJECTIVES

The contact investigation of tuberculosis (TB) index case is one of the critical elements pointed by the WHO to reach the end of the TB epidemic. The scoping review aimed to map out the recommended and the adopted processes applied to active contact investigation of TB index case in African Portuguese-speaking countries (PALOP).

DESIGN

Scoping review.

DATA SOURCES

We searched B-on, Cochrane Library, PubMed, Web of Science, Scopus, WHOLIS, IRIS, OKR, each country's Ministry of Health websites, WHO, Global Fund, World Bank and bibliographic reference lists from February to May 2020.

ELIGIBILITY CRITERIA

All available literature on TB contact investigation in each country part of PALOP (Angola, Cape Verde, Guinea-Bissau, Mozambique and Sao Tome and Principe) published from 1 January 2010 to 31 January2020.

DATA EXTRACTION AND SYNTHESIS

A data-charting form was developed to extract data on documents' characteristics and variables pertinent to the TB contact investigation process. Before qualitative analysis, we thematically synthesised findings and converted them into appropriate text units.

RESULTS

Fifteen documents were included in the scoping review. The recommended processes for TB contact investigation were identified only for Cape Verde and Mozambique. It included clinical evaluation, counselling and testing for HIV, chest radiography, tuberculin skin test, sputum smear microscopy or Xpert MTB/RIF. The adopted processes were detected only in research studies from Angola, Guinea-Bissau and Mozambique. Therefore, they cannot be assumed as adopted within the scope of the national programmes of the respective countries.

CONCLUSION

This review highlights the scarcity of references on TB contact investigation in PALOP at the End TB Strategy era. Furthermore, it is well clear the importance of an information system that provides actual data for assessing the real impact of such interventions in controlling the disease in African Portuguese-speaking countries.

Screening tests for active pulmonary tuberculosis in children

BACKGROUND

Globally, children under 15 years represent approximately 12% of new tuberculosis cases, but 16% of the estimated 1.4 million deaths. This higher share of mortality highlights the urgent need to develop strategies to improve case detection in this age group and identify children without tuberculosis disease who should be considered for tuberculosis preventive treatment. One such strategy is systematic screening for tuberculosis in high-risk groups.

OBJECTIVES

To estimate the sensitivity and specificity of the presence of one or more tuberculosis symptoms, or symptom combinations; chest radiography (CXR); Xpert MTB/RIF; Xpert Ultra; and combinations of these as screening tests for detecting active pulmonary childhood tuberculosis in the following groups. - Tuberculosis contacts, including household contacts, school contacts, and other close contacts of a person with infectious tuberculosis. - Children living with HIV. - Children with pneumonia. - Other risk groups (e.g. children with a history of previous tuberculosis, malnourished children). - Children in the general population in high tuberculosis burden settings.

SEARCH METHODS

We searched six databases, including the Cochrane Central Register of Controlled Trials, MEDLINE, and Embase, on 14 February 2020 without language restrictions and contacted researchers in the field.

SELECTION CRITERIA

Cross-sectional and cohort studies where at least 75% of children were aged under 15 years. Studies were eligible if conducted for screening rather than diagnosing tuberculosis. Reference standards were microbiological (MRS) and composite reference standard (CRS), which may incorporate symptoms and CXR.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed study quality using QUADAS-2. We consolidated symptom screens across included studies into groups that used similar combinations of symptoms as follows: one or more of cough, fever, or poor weight gain and one or more of cough, fever, or decreased playfulness. For combination of symptoms, a positive screen was the presence of one or more than one symptom. We used a bivariate model to estimate pooled sensitivity and specificity with 95% confidence intervals (CIs) and performed analyses separately by reference standard. We assessed certainty of evidence using GRADE.

MAIN RESULTS

Nineteen studies assessed the following screens: one symptom (15 studies, 10,097 participants); combinations of symptoms (12 studies, 29,889 participants); CXR (10 studies, 7146 participants); and Xpert MTB/RIF (2 studies, 787 participants). Several studies assessed more than one screening test. No studies assessed Xpert Ultra. For 16 studies (84%), risk of bias for the reference standard domain was unclear owing to concern about incorporation bias. Across other quality domains, risk of bias was generally low. Symptom screen (verified by CRS) One or more of cough, fever, or poor weight gain in tuberculosis contacts (4 studies, tuberculosis prevalence 2% to 13%): pooled sensitivity was 89% (95% CI 52% to 98%; 113 participants; low-certainty evidence) and pooled specificity was 69% (95% CI 51% to 83%; 2582 participants; low-certainty evidence). Of 1000 children where 50 have pulmonary tuberculosis, 339 would be screen-positive, of whom 294 (87%) would not have pulmonary tuberculosis (false positives); 661 would be screen-negative, of whom five (1%) would have pulmonary tuberculosis (false negatives). One or more of cough, fever, or decreased playfulness in children aged under five years, inpatient or outpatient (3 studies, tuberculosis prevalence 3% to 13%): sensitivity ranged from 64% to 76% (106 participants; moderate-certainty evidence) and specificity from 37% to 77% (2339 participants; low-certainty evidence). Of 1000 children where 50 have pulmonary tuberculosis, 251 to 636 would be screen-positive, of whom 219 to 598 (87% to 94%) would not have pulmonary tuberculosis; 364 to 749 would be screen-negative, of whom 12 to 18 (2% to 3%) would have pulmonary tuberculosis. One or more of cough, fever, poor weight gain, or tuberculosis close contact (World Health Organization four-symptom screen) in children living with HIV, outpatient (2 studies, tuberculosis prevalence 3% and 8%): pooled sensitivity was 61% (95% CI 58% to 64%; 1219 screens; moderate-certainty evidence) and pooled specificity was 94% (95% CI 86% to 98%; 201,916 screens; low-certainty evidence). Of 1000 symptom screens where 50 of the screens are on children with pulmonary tuberculosis, 88 would be screen-positive, of which 57 (65%) would be on children who do not have pulmonary tuberculosis; 912 would be screen-negative, of which 19 (2%) would be on children who have pulmonary tuberculosis. CXR (verified by CRS) CXR with any abnormality in tuberculosis contacts (8 studies, tuberculosis prevalence 2% to 25%): pooled sensitivity was 87% (95% CI 75% to 93%; 232 participants; low-certainty evidence) and pooled specificity was 99% (95% CI 68% to 100%; 3281 participants; low-certainty evidence). Of 1000 children, where 50 have pulmonary tuberculosis, 63 would be screen-positive, of whom 19 (30%) would not have pulmonary tuberculosis; 937 would be screen-negative, of whom 6 (1%) would have pulmonary tuberculosis. Xpert MTB/RIF (verified by MRS) Xpert MTB/RIF, inpatient or outpatient (2 studies, tuberculosis prevalence 1% and 4%): sensitivity was 43% and 100% (16 participants; very low-certainty evidence) and specificity was 99% and 100% (771 participants; moderate-certainty evidence). Of 1000 children, where 50 have pulmonary tuberculosis, 31 to 69 would be Xpert MTB/RIF-positive, of whom 9 to 19 (28% to 29%) would not have pulmonary tuberculosis; 969 to 931 would be Xpert MTB/RIF-negative, of whom 0 to 28 (0% to 3%) would have tuberculosis. Studies often assessed more symptoms than those included in the index test and symptom definitions varied. These differences complicated data aggregation and may have influenced accuracy estimates. Both symptoms and CXR formed part of the CRS (incorporation bias), which may have led to overestimation of sensitivity and specificity.

AUTHORS' CONCLUSIONS

We found that in children who are tuberculosis contacts or living with HIV, screening tests using symptoms or CXR may be useful, but our review is limited by design issues with the index test and incorporation bias in the reference standard. For Xpert MTB/RIF, we found insufficient evidence regarding screening accuracy. Prospective evaluations of screening tests for tuberculosis in children will help clarify their use. In the meantime, screening strategies need to be pragmatic to address the persistent gaps in prevention and case detection that exist in resource-limited settings.

Contribution of Xpert® MTB/RIF to tuberculosis case finding among pregnant women in Botswana

Setting

Seven health facilities with antenatal care (ANC) clinics in two districts near Gaborone, Botswana.

Objectives

To determine 1) the prevalence of tuberculosis (TB) and HIV-TB co-infection in pregnancy, and 2) the sensitivities of symptomatic TB screening and Xpert testing against gold standard culture.

Design

This was a cross-sectional study. Pregnant women were randomly enrolled and screened using TB symptoms. HIV status was determined from ANC clinics' client records. Two sputum specimens were collected from all clients and each was tested using Xpert^® and culture for Mycobacterium tuberculosis.

Results

Of 407 cases, eight had one or more TB symptoms, and all tested negative with Xpert^® and culture. Another two (0.5%, 95%CI 0.08-1.96) asymptomatic clients tested positive with both tests. The adjusted TB prevalence was higher than that of the general population (0.6% vs. 0.24%; P < 0.001). The prevalence of TB among HIV-positive and HIV-negative clients was 1/69 (1.45%, 95%CI 0.29-2.61) and 1/336 (0.3%, 95%CI 0.23-0.83), respectively (Fisher's exact test P = 0.312). Xpert^® demonstrated a 100% sensitivity and 100% specificity, while symptom screening had 0.0% sensitivity and 98% specificity.

Conclusions

TB prevalence among pregnant women was high and TB symptom screening had limited ability to detect TB. An alternative TB screening algorithm for pregnant women is urgently needed irrespective of TB symptoms.

Outcomes of Community-Based Systematic Screening of Household Contacts of Patients with Multidrug-Resistant Tuberculosis in Myanmar

Screening of household contacts of patients with multidrug-resistant tuberculosis (MDR-TB) is a crucial active TB case-finding intervention. Before 2016, this intervention had not been implemented in Myanmar, a country with a high MDR-TB burden. In 2016, a community-based screening of household contacts of MDR-TB patients using a systematic TB-screening algorithm (symptom screening and chest radiography followed by sputum smear microscopy and Xpert-MTB/RIF assays) was implemented in 33 townships in Myanmar. We assessed the implementation of this intervention, how well the screening algorithm was followed, and the yield of active TB. Data collected between April 2016 and March 2017 were analyzed using logistic and log-binomial regression. Of 620 household contacts of 210 MDR-TB patients enrolled for screening, 620 (100%) underwent TB symptom screening and 505 (81%) underwent chest radiography. Of 240 (39%) symptomatic household contacts, 71 (30%) were not further screened according to the algorithm. Children aged <15 years were less likely to follow the algorithm. Twenty-four contacts were diagnosed with active TB, including two rifampicin- resistant cases (yield of active TB = 3.9%, 95% CI: 2.3%-6.5%). The highest yield was found among children aged <5 years (10.0%, 95% CI: 3.6%-24.7%). Household contact screening should be strengthened, continued, and scaled up for all MDR-TB patients in Myanmar.

Intensified household contact tracing, prevention and treatment support versus enhanced standard of care for contacts of tuberculosis cases in South Africa: study protocol for a household cluster-randomised trial

BACKGROUND

Household contact tracing of index TB cases has been advocated as a key part of TB control for many years, but has not been widely implemented in many low-resource setting because of the current dearth of high quality evidence for effectiveness. Innovative strategies for earlier, more effective treatment are particularly important in contexts with hyper-endemic levels of HIV, where levels of TB infection remain extremely high.

METHODS

We present the design of a household cluster-randomised controlled trial of interventions aimed at improving TB-free survival and reducing childhood prevalence of Mycobacterium tuberculosis infection among household contacts of index TB cases diagnosed in two provinces of South Africa. Households of index TB cases will be randomly allocated in a 1:1 ratio to receive either an intensified home screening and linkage for TB and HIV intervention, or enhanced standard of care. The primary outcome will compare between groups the TB-free survival of household contacts over 15 months. All participants, or their next-of-kin, will provide written informed consent to participate.

DISCUSSION

Evidence from randomised trials is required to identify cost-effective approaches to TB case-finding that can be applied at scale in sub-Saharan Africa.

TRIAL REGISTRATION

ISRCTN16006202 (01/02/2017: retrospectively registered) and NHREC4399 (11/04/2016: prospectively registered). Protocol version: 4.0 (date: 18th January 2018).

Undetected tuberculosis at enrollment and after hospitalization in medical and oncology wards in Botswana

Cancer patients are at higher risk of tuberculosis (TB) infection, especially in hospital settings with high TB/HIV burden. The study was implemented among adult patients admitted to the largest tertiary-level referral hospital in Botswana. We estimated the TB prevalence at admission and the rate of newly diagnosed TB after hospitalization in the medical and oncology wards, separately. Presumptive TB cases were identified at admission through symptom screening and underwent the diagnostic evaluation through GeneXpert. Patients with no evidence of TB were followed-up until TB diagnosis or the end of the study. In the medical and oncology wards, four of 867 admitted patients and two of 240 had laboratory-confirmed TB at admission (prevalence = 461.4 and 833.3 per 100,000, respectively.) The post-admission TB rate from the medical wards was 28.3 cases per 1,000 person-year during 424.5 follow-up years (post-admission TB rate among HIV-positive versus. -negative = 54.1 and 9.8 per 1,000 person-year, respectively [Rate Ratio = 5.5]). No post-admission TB case was detected from the oncology ward. High rates of undetected TB at admission at both medical and oncology wards, and high rate of newly diagnosed TB after admission at medical wards suggest that TB screening and diagnostic evaluation should target all patients admitted to a hospital in high-burden settings.

Prevention of tuberculosis in household members: estimates of children eligible for treatment

Objective

To estimate of the number of children younger than 5 years who were household contacts of people with tuberculosis and were eligible for tuberculosis preventive treatment in 2017.

Methods

To estimate the number of eligible children, we obtained national values for the number of notified cases of bacteriologically confirmed pulmonary tuberculosis in 2017, the proportion of the population younger than 5 years in 2017 and average household size from published sources. We obtained global values for the number of active tuberculosis cases per household with an index case and for the prevalence of latent tuberculosis infection among children younger than 5 years who were household contacts of a tuberculosis case through systematic reviews, meta-analysis and Poisson regression models.

Findings

The estimated number of children younger than 5 years eligible for tuberculosis preventive treatment in 2017 globally was 1.27 million (95% uncertainty interval, UI: 1.24–1.31), which corresponded to an estimated global coverage of preventive treatment in children of 23% at best. By country, the estimated number ranged from less than one in the Bahamas, Iceland, Luxembourg and Malta to 350 000 (95% UI: 320 000–380 000) in India. Regionally, the highest estimates were for the World Health Organization (WHO) South-East Asia Region (510 000; 95% UI: 450 000–580 000) and the WHO African Region (470 000; 95% UI: 440 000–490 000).

Conclusion

Tuberculosis preventive treatment in children was underutilized globally in 2017. Treatment should be scaled up to help eliminate the pool of tuberculosis infection and achieve the End TB Strategy targets.

Infectivity of Mycobacterium tuberculosis Genotypes and Outcome of Contact Investigation in Classroom in Guangxi, China

OBJECTIVE

To evaluate the infectivity of Mycobacterium tuberculosis (M.tb) genotypes of index cases in the classroom of adolescent schools in Guangxi, China.

METHODS

Adolescent school tuberculosis (TB) contact investigations were conducted for all reported index TB cases from November 2016 to December 2017 in Guangxi, China. Genotypes of index cases and contact cases were identified by 15-loci mycobacterial interspersed repetitive units-variable number tandem repeat and spoligotyping. Outcome variable was 5 levels' order of tuberculin skin test (TST) results to new active TB [0-5 mm, 6-9 mm, 10-14 mm, ≥ 15 mm (without TB), and ≥15 mm (with TB)]. Multivariate ordered logistic regression analysis was performed to evaluate the independent effect of genotypes of index case on contact screening outcome.

RESULTS

Beijing genotype occurred more commonly in female index patients. One genotypic cluster of two index cases and one cluster of two contact cases were detected. The association between infectivity of Beijing genotype of index cases and outcome of contact investigation was statistically significant in univariate analysis but no so after adjustment for characteristics of contacts and sex of index cases (P value=0.057). Female index cases increased the chance for TB infection/being active TB among contacts (ordinal odds ratio = 1.39, 95% confidence interval: 1.21, 1.60). Contacts who studied in the middle school, who with non-Han ethnicity and who without BCG scar had increased risk for TB infection/being active TB.

CONCLUSION

There was not enough evidence from our data to support that Beijing strains were more infective than non-Beijing strains in TB transmission in school setting.

Adolescent tuberculosis associated with tuberculosis exposure in classrooms and dorm rooms in Guangxi, China

OBJECTIVE

Quantify tuberculosis (TB) risk attributable to dorm room exposure in addition to classroom exposure.

METHODS

Adolescent school contact investigations were conducted for every reported index TB case, and similar contact investigations were conducted in selected community-control classes from November 2016 to October 2017 in Guangxi, China.

RESULTS

A total of 6263 contacts of 112 index TB cases and 6130 classmates of 112 controls were investigated. There were 14, 12, and 2 new active TB cases detected among classmates/non-roommates of index cases, classmates/roommates of index cases, and control classmates, respectively. Compared with control contacts, the adjusted relative risk (95% confidence interval (CI)) and population attributable fraction (PAF) for being a classmate/non-roommate of the index case increased the risk of active TB diagnosis to 8.44 (95% CI: 1.31-54.48) and 44.1%. The adjusted RR and PAF for being a classmate/roommate of the index case was 29.37 (95% CI: 3.80, 227.11) and 41.4%. Being classmates/roommates significantly increased the risk of TB compared to a classmate/non-roommate of the index case (RR=3.48, 95% CI: 1.64, 7.40).

CONCLUSION

The additional risk of TB due to exposure in the dorm room should be taken into account in planning of TB prevention and control in boarding schools.

Source case identification in HIV-exposed infants and tuberculosis diagnosis in an isoniazid prevention study

BACKGROUND

Identifying source cases of children exposed to tuberculosis (TB) is challenging. We examined the time-point of obtaining contact information of TB source cases in human immunodeficiency virus (HIV) infected and HIV-exposed uninfected (HEU) children in a randomised, placebo-controlled trial of pre-exposure to isoniazid prophylaxis.

METHODS

A total of 543 HIV-infected and 808 HEU infants without TB exposure aged 3-4 months were enrolled between 2004 and 2008. At 3-monthly follow-up, infants were evaluated for TB and care givers were asked about new TB exposure.

RESULTS

In total, 128 cases of TB disease and 40 deaths were recorded among 19% (105/543) of the HIV-infected and 8% (63/808) of the HEU children; 229 TB contact occasions were reported in 205/1351 (15%) children, of which 83% (189/229) were in the household. Of the 189 household contacts, 108 (53%) underwent microbiological evaluations; 81% (87/108) were positive. HIV-infected and HEU infants had similar frequencies of TB contact: in 48% of infants with definite TB, 58% with probable TB and 43% with possible TB. Of 128 children diagnosed with TB, a TB contact was identified for 59. Of these, 29/59 (49%) were identified at or after the child's TB diagnosis.

CONCLUSION

TB source cases are often identified at or after a child's TB diagnosis. More effort is required for earlier detection.

Feasibility and Effectiveness of Tuberculosis Active Case-Finding among Children Living with Tuberculosis Relatives: a Cross-Sectional Study in Guinea-Bissau

Background and objectives

The World Health Organization End tuberculosis (TB) Strategy, approved in 2014, aims at a 90% reduction in TB deaths and an 80% reduction in TB incidence rate by 2030. One of the suggested interventions is the systematic screening of people with suspected TB, belonging to specific risk groups. The Hospital Raoul Follereau (HRF) in Bissau, Guinea-Bissau, is the National Reference Hospital for Tuberculosis and Lung Disease of the country. We performed an active case-finding program among pediatric age family members and cohabitants of admitted adult TB patients, from January to December 2013.

Methods

Newly admitted adult patients with a diagnosis of TB were invited to bring their family members or cohabitants in childhood age for clinical evaluation in a dedicated outpatient setting within the hospital compound. All the children brought to our attention underwent a medical examination and chest x-ray. In children with clinical and/or radiologic finding consistent with pulmonary TB, a sputum-smear was requested.

Results

All admitted adult patients accepted to bring their children cohabitants. In total, 287 children were examined in 2013. Forty-four patients (15%) were diagnosed with TB. The number needed to screen (NNS) to detect one case of TB was 7. 35 patients (80%) had pulmonary TB; 2 of them were sputum smear-positive. No adjunctive personnel cost was necessary for the intervention.

Conclusions

A hospital-based TB active case-finding program targeted to high-risk groups like children households of severely ill admitted patients with TB can successfully be implemented in a country with limited resources.

BUTIMBA: Intensifying the Hunt for Child TB in Swaziland through Household Contact Tracing

Background

Limited data exists to inform contact tracing guidelines in children and HIV-affected populations. We evaluated the yield and additionality of household contact and source case investigations in Swaziland, a TB/HIV high-burden setting, while prioritizing identification of childhood TB.

Methods

In partnership with 7 local TB clinics, we implemented standardized contact tracing of index cases (IC) receiving TB treatment. Prioritizing child contacts and HIV-affected households, screening officers screened contacts for TB symptoms and to identify risk factors associated with TB. We ascertained factors moderating the yield of contact tracing and measured the impact of our program by additional notifications.

Results

From March 2013 to November 2015, 3,258 ICs (54% bacteriologically confirmed; 70% HIV-infected; 85% adults) were enrolled leading to evaluation of 12,175 contacts (median age 18 years, IQR 24–42; 45% children; 9% HIV-infected). Among contacts, 196 TB cases (56% bacteriologically confirmed) were diagnosed resulting in a program yield of 1.6% for all forms of TB. The number needed to screen (NNS) to identify a bacteriologically confirmed TB case or all forms TB case traced from a child IC <5 years was respectively 62% and 40% greater than the NNS for tracing from an adult IC. In year one, we demonstrated a 32% increase in detection of bacteriologically confirmed child TB. Contacts were more likely to have TB if <5 years (OR = 2.0), HIV-infected (OR = 4.9), reporting ≥1 TB symptoms (OR = 7.7), and sharing a bed (OR = 1.7) or home (OR = 1.4) with the IC. There was a 1.4 fold increased chance of detecting a TB case in households known to be HIV-affected.

Conclusion

Contact tracing prioritizing children is not only feasible in a TB/HIV high-burden setting but contributes to overall case detection. Our findings support WHO guidelines prioritizing contact tracing among children and HIV-infected populations while highlighting potential to integrate TB and HIV case finding.

Evaluation of a Mobile Health Approach to Tuberculosis Contact Tracing in Botswana

Tuberculosis (TB) contact tracing is typically conducted in resource-limited settings with paper forms, but this approach may be limited by inefficiencies in data collection, storage, and retrieval and poor data quality. In Botswana, we developed, piloted, and evaluated a mobile health (mHealth) approach to TB contact tracing that replaced the paper form-based approach for a period of six months. For both approaches, we compared the time required to complete TB contact tracing and the quality of data collected. For the mHealth approach, we also administered the Computer System Usability Questionnaire to 2 health care workers who used the new approach, and we identified and addressed operational considerations for implementation. Compared to the paper form-based approach, the mHealth approach reduced the median time required to complete TB contact tracing and improved data quality. The mHealth approach also had favorable overall rating, system usefulness, information quality, and interface quality scores on the Computer System Usability Questionnaire. Overall, the mHealth approach to TB contact tracing improved on the paper form-based approach used in Botswana. This new approach may similarly benefit TB contact tracing efforts in other resource-limited settings.

Factors influencing health care workers' implementation of tuberculosis contact tracing in Kweneng, Botswana

INTRODUCTION

TB contact tracing rates remain low in high burden settings and reasons for this are not well known. We describe factors that influence health care workers' (HCW) implementation of TB contact tracing (CT) in a high TB burden district of Botswana.

METHODS

Data were collected using questionnaires and in-depth interviews in 31 of the 52 health facilities in Kweneng East Health District. Responses were summarized using summary statistics and comparisons between HCW groups were done using parametric or non-parametric tests as per normality of the data distribution.

RESULTS

One hundred and four HCWs completed questionnaires. Factors that influenced HCW TB contact tracing were their knowledge, attitudes and practices as well as personal factors including decreased motivation and lack of commitment. Patient factors included living further away from the clinic, unknown residential address and high rates of migration and mobility. Administrative factors included staff shortages, lack of transport, poor reporting of TB cases and poor medical infrastructure e.g. suboptimal laboratory services. A national HCW strike and a restructuring of the health system emerged as additional factors during in-depth interviews of TB coordinators.

CONCLUSION

Multiple factors lead to poor TB contact tracing in this district. Interventions to increase TB contact tracing will be informed by these findings.

Integrated Source Case Investigation for Tuberculosis (TB) and HIV in the Caregivers and Household Contacts of Hospitalised Young Children Diagnosed with TB in South Africa: An Observational Study

BACKGROUND

Contact tracing, to identify source cases with untreated tuberculosis (TB), is rarely performed in high disease burden settings when the index case is a young child with TB. As TB is strongly associated with HIV infection in these settings, we used source case investigation to determine the prevalence of undiagnosed TB and HIV in the caregivers and household contacts of hospitalised young children diagnosed with TB in South Africa.

METHODS

Caregivers and household contacts of 576 young children (age ≤7 years) with TB diagnosed between May 2010 and August 2012 were screened for TB and HIV. The primary outcome was the detection of laboratory-confirmed, newly-diagnosed TB disease and/or HIV-infection in close contacts.

RESULTS

Of 576 caregivers, 301 (52·3%) self-reported HIV-positivity. Newly-diagnosed HIV infection was detected in 63 (22·9%) of the remaining 275 caregivers who self-reported an unknown or negative HIV status. Screening identified 133 (23·1%) caregivers eligible for immediate anti-retroviral therapy (ART). Newly-diagnosed TB disease was detected in 23 (4·0%) caregivers. In non-caregiver household contacts (n = 1341), the prevalence of newly-diagnosed HIV infection and TB disease was 10·0% and 3·2% respectively. On average, screening contacts of every nine children with TB resulted in the identification of one case of newly-diagnosed TB disease, three cases of newly diagnosed HIV-infection, and three HIV-infected persons eligible for ART.

CONCLUSION

In high burden countries, source case investigation yields high rates of previously undiagnosed HIV and TB infection in the close contacts of hospitalised young children diagnosed with TB. Furthermore, integrated screening identifies many individuals who are eligible for immediate ART. Similar studies, with costing analyses, should be undertaken in other high burden settings-integrated source case investigation for TB and HIV should be routinely undertaken if our findings are confirmed.

Yield of close contact tracing using two different programmatic approaches from tuberculosis index cases: a retrospective quasi-experimental study

Background

Being a contact of a pulmonary tuberculosis (TB) case is a risk factor for active and latent TB. The objective of this study is to determine the contact tracing yield using two different programmatic definitions of close contact in the city of Rio de Janeiro, Brazil.

Methods

This is a retrospective quasi-experimental study. Data were obtained by reviewing the medical records from TB index cases and their close contacts admitted to the Outpatient TB Clinic of the Institute of Thoracic Diseases, University of Rio de Janeiro. From January 2001 to December 2004, a close contact was defined as an individual who shared an enclosed space with a TB index case for a total period of ≥ 100 hours, whereas from January 2005 to December 2008 the definition of close contact was changed to an individual who shared an enclosed space with a TB index case ≥ 4 hours a week. The primary outcome of this study was newly diagnosed pulmonary TB cases and the secondary outcome was the prevalence of latent TB infection (LTBI) among close contacts during both periods.

Results

From 2001–2004, 810 close contacts from 257 index cases were evaluated and the prevalence of active TB and LTBI were 2% (16/810) and 62% (496/794), respectively. From 2005–2008, 1,310 close contacts from 369 index cases were identified and the prevalence of active TB and LTBI were 2.7% (35/1,310) and 69% (877/1,275), respectively. There was not a statically significant difference in the detection of active TB (p = 0.3) between the 2 time periods, but the detection of LTBI was significant higher (p = 0.003). The number needed to screen (contacts/new cases) decreased from 50 to 37 and the number need to contact trace (index cases/new cases) decreased from 16 to 10 from 2001–2004 to 2005–2008.

Conclusion

In conclusion, the findings of this study suggest that the less conservative definition of TB close contacts (sharing space ≥ 4 h/week) can be a helpful tool for increasing the rate of diagnosis for newly active pulmonary TB cases and for the detection of LTBI among contacts of active pulmonary TB cases.