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.

Yield of tuberculosis among household contacts of tuberculosis patients in Accra, Ghana

Background

The End TB Strategy calls for systematic screening of selected high-risk groups including contacts of tuberculosis (TB) cases to facilitate early TB case detection. Contact investigation is not usually routinely practiced in low TB burden countries, such as Ghana, with consequent paucity of data on the yield of TB case detection from such interventions. This study’s objective was to document the outcomes and feasibility of implementing contact investigation activities under programmatic conditions in Ghana.

Methods

Retrospective analyses were conducted of abstracted data from the National TB Program, following a contact investigation intervention for TB cases diagnosed in 10 facilities in Accra from June 2010 to December 2014. Various proportions and yield from number of contacts needed to screen (NNS) and number needed to test (NNT) to detect a TB case were assessed.

Results

Overall, out of the 8519 listed contacts of 3267 index cases, 8166 (96%) were screened and 614 (7.5%) were identified as presumptive TB. Out of these, 438 (71%) underwent sputum smear microscopy/evaluation and 53 TB cases were diagnosed. Of these, 56.6% were males, and 49% had sputum smear-positive TB, 38% had sputum smear-negative TB, and 7% had extra-pulmonary TB. The NNS and NNT to detect a TB case of all forms were 154 and 8, respectively. The proportion of TB cases with contacts listed and proportion of contacts screened annually were 88–96% and 83–100%, respectively. The proportion of presumptive TB cases tested and proportion of TB cases diagnosed among contacts tested that were 100% and 36%, respectively, in 2010 dropped to 40% and 14%, respectively, by 2014.

Conclusions

The study demonstrates that contact identification and prioritization components of a contact investigation were feasible, but overall yield of TB cases may have been lower due to the declining rate of clinical evaluation of presumptive TB contacts over time. Addressing barriers to accessing appropriate diagnostic tests may enhance yield from contact investigation in Ghana.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0396-5) contains supplementary material, which is available to authorized users.

Stakeholder perspectives for optimization of tuberculosis contact investigation in a high-burden setting

Introduction

Optimal tuberculosis contact investigation impacts TB prevention, timely case finding and linkage to care, however data on routine implementation in high burden contexts is limited.

Materials and methods

In a multi-method qualitative study based on individual interviews with TB patients, facility observations and focus group discussions with health workers (HWs) in 13 public health facilities, and key informant interviews with governmental and non-governmental experts, we describe TB contact investigation in the context of an urban setting in Kenya and identify opportunities for optimization.

Results

Invitation of TB patients to bring close contacts by HWs was key for all patient decisions that led to contact screening in addition to patients’ understanding of TB transmission and desire to avoid contacts suffering from TB. Sub-optimal HW enquiry of TB patients and contacts presenting at the facility were missed opportunities which stemmed from lack of standardized operational procedures, documentation tools and HW training. Stakeholders proposed provision of fast tracked and holistic health packages for contacts seeking TB screening, and sustainable government led funding for the requisite infrastructure and workforce.

Conclusion

TB contact invitation by HWs leading to contact screening occurs in this context. Stakeholder perspectives inform the design of an operational framework for optimized delivery.

[Results of tuberculosis screening in children with household contact]

INTRODUCTION

Tuberculosis screening in children is important to identify and treat latent tuberculosis infection and thus avoid progression to disease.

METHODS

It is a prospective study realized in 83 children between November 2009 and January 2013 who consulted after a household contact for tuberculosis in the pediatric department B of Abderrahmen Mami hospital of Ariana.

RESULTS

The mean age of the children was 4.8 years (3 months-15 years). A latent tuberculosis infection was diagnosed in 31.3% of children, 10.8% had tuberculosis and 57.8% were considered healthy. Fifty-seven children (68.7%) had a close daytime contact with the index and 57.8% slept in the same bedroom of the contaminator. The identified risk factors were the diagnosis delay of the index of more than 30 days (P=0.023), presence of cavitations on the chest X-ray of the index (P=0.029) and a close daytime contact (P=0.004).

CONCLUSION

Our study showed a high rate of contamination in children with a household contact. Efforts are needed to shorten the time to diagnosis of adults' tuberculosis.

Increased Case Notification through Active Case Finding of Tuberculosis among Household and Neighbourhood Contacts in Cambodia

Background

Globally, there has been growing evidence that suggests the effectiveness of active case finding (ACF) for tuberculosis (TB) in high-risk populations. However, the evidence is still insufficient as to whether ACF increases case notification beyond what is reported in the routine passive case finding (PCF). In Cambodia, National TB Control Programme has conducted nationwide ACF with Xpert MTB/RIF that retrospectively targeted household and neighbourhood contacts alongside routine PCF. This study aims to investigate the impact of ACF on case notifications during and after the intervention period.

Methods

Using a quasi-experimental cluster randomized design with intervention and control arms, we compared TB case notification during the one-year intervention period with historical baseline cases and trend-adjusted expected cases, and estimated additional cases notified during the intervention period (separately for Year 1 and Year 2 implementation). The proportion of change in case notification was compared between intervention and control districts for Year 1. The quarterly case notification data from all intervention districts were consolidated, aligning different implementation quarters, and separately analysed to explore the additionality. The effect of the intervention on the subsequent case notification during the post-intervention period was also assessed.

Results

In Year 1, as compared to expected cases, 1467 cases of all forms (18.5%) and 330 bacteriologically-confirmed cases (9.6%) were additionally notified in intervention districts, whereas case notification in control districts decreased by 2.4% and 2.3%, respectively. In Year 2, 2737 cases of all forms (44.3%) and 793 bacteriologically-confirmed cases (38%) were additionally notified as compared to expected cases. The proportions of increase in case notifications from baseline cases and expected cases to intervention period cases were consistently higher in intervention group than in control group. The consolidated quarterly data showed sharp rises in all forms and bacteriologically-confirmed cases notified during the intervention quarter, with 64.6% and 68.4% increases (compared to baseline cases), and 46% and 52.9% increases (compared to expected cases), respectively. A cumulative reduction of case notification for five quarters after ACF reached more than -200% of additional cases.

Conclusions

The Cambodia’s ACF with Xpert MTB/RIF that retrospectively targeted household and neighbourhood contacts resulted in the substantial increase in case notification during the intervention period and reduced subsequent case notification during the post-intervention period. The applicability of retrospective contact investigation in other high-burden settings should be explored.

The yield of screening symptomatic contacts of multidrug-resistant tuberculosis cases at a tertiary hospital in Addis Ababa, Ethiopia

BACKGROUND

Early detection and treatment of multidrug-resistant tuberculosis (MDR-TB, resistant to isoniazid and rifampicin) is an urgent global priority. Identifying and tracing close contacts of patients with MDR-TB could be a feasible strategy to achieve this goal. However, there is limited experience with contact tracing among patients with drug-resistant tuberculosis both globally and in Ethiopia. Here we present our findings on the extent of screening symptomatic contacts and its yield in a tertiary hospital in a major urban setting in Ethiopia.

RESULTS

Symptomatic household contacts were identified in 29 (5.7%) of 508 index cases treated at the hospital. There were a total of 155 family members in the households traced of whom 16 (10%) had confirmed MDR-TB. At least one confirmed MDR-TB cases was identified in 15 (51.7%) of the 29 traced households.

CONCLUSIONS

Tracing symptomatic contacts of MDR-TB cases could be a high yield strategy for early detection and treatment of MDR-TB cases in the community. The approach should be promoted for wider adoption and dissemination. Larger scale studies should be done to determine its effectiveness and sustainability in similar settings.

Silicosis mortality with respiratory tuberculosis in the United States, 1968-2006

The presence of tuberculosis (TB) in patients with silicosis increases mortality risk. To characterize silicosis-respiratory TB comortality in the United States, the authors used 1968-2006 National Center for Health Statistics multiple cause-of-death data for decedents aged ≥25 years. The authors calculated proportionate mortality ratios (PMRs) using available information on decedents' industries and occupations reported from 26 states from 1985 through 1999. Among 16,648 silicosis deaths, 2,278 (13.7%) had respiratory TB listed on the death certificate. Of silicosis-respiratory TB deaths, 1,666 decedents (73.1%) were aged ≥65 years, 2,255 (99.0%) were male, and 1,893 (83.1%) were white. Silicosis-respiratory TB deaths declined 99.5% during the study period (P < 0.001 for time-related trend), from 239.8 per year during 1968-1972 to 1.2 per year during 2002-2006, with no reported deaths in 2006. Silicosis-respiratory TB deaths reported from Pennsylvania (n = 525; 1.29 per million population), Ohio (n = 258; 0.81 per million), and West Virginia (n = 146; 2.35 per million) accounted for 40.8% of all such deaths in the United States. The highest PMR for silicosis-respiratory TB death was associated with the "miscellaneous nonmetallic mineral and stone products" industry (PMR = 73.7, 95% confidence interval: 33.8, 139.8). In the United States, 2006 marked the first year since 1968 with no silicosis-respiratory TB deaths. The substantial decline in silicosis-respiratory TB comortality probably reflects prevention and control measures for both diseases.