Risk factors for pulmonary tuberculosis recurrence, relapse and reinfection: a systematic review and meta-analysis

BACKGROUND

The rate of pulmonary tuberculosis (TB) recurrence is substantial. Identifying risk factors can support the development of prevention strategies.

METHODS

We retrieved studies published between 1 January 1980 and 31 December 2022 that assessed factors associated with undifferentiated TB recurrence, relapse or reinfection. For factors reported in at least four studies, we performed random-effects meta-analysis to estimate a pooled relative risk (RR). We assessed heterogeneity, risk of publication bias and certainty of evidence.

RESULTS

We included 85 studies in the review; 81 documented risk factors for undifferentiated recurrence, 17 for relapse and 10 for reinfection. The scope for meta-analyses was limited given the wide variety of factors studied, inconsistency in control for confounding and the fact that only few studies employed molecular genotyping. Factors that significantly contributed to moderately or strongly increased pooled risk and scored at least moderate certainty of evidence were: for undifferentiated recurrence, multidrug resistance (MDR) (RR 3.49; 95% CI 1.86 to 6.53) and fixed-dose combination TB drugs (RR 2.29; 95% CI 1.10 to 4.75) in the previous episode; for relapse, none; and for reinfection, HIV infection (RR 4.65; 95% CI 1.71 to 12.65). Low adherence to treatment increased the pooled risk of recurrence 3.3-fold (95% CI 2.37 to 4.62), but the certainty of evidence was weak.

CONCLUSION

This review emphasises the need for standardising methods for TB recurrence research. Actively pursuing MDR prevention, facilitating retention in treatment and providing integrated care for patients with HIV could curb recurrence rates. The use of fixed-dose combinations of TB drugs under field conditions merits further attention.

PROSPERO REGISTRATION NUMBER

CRD42018077867.

Delays in health seeking, diagnosis and treatment for tuberculosis patients in Mongolia: an analysis of surveillance data, 2018-2021

Early diagnosis and treatment of infectious tuberculosis (TB) is essential to the attainment of global targets specified in the End TB Strategy. Using case-based TB surveillance data, we analysed delays in health seeking, diagnosis and treatment among TB patients in Mongolia from 2018 to 2021. We calculated the median and interquartile range (IQR) for "diagnostic delay," defined as the time from symptom onset to diagnosis, subdivided into "health-seeking delay" (time from symptom onset to first visit to a health facility) and "health facility diagnostic delay" (time from first health facility visit to diagnosis), and for "treatment delay," defined as the time from diagnosis to start of treatment. We also calculated "total delay," defined as the time from symptom onset to treatment start. Based on data for 13 968 registered TB patients, the median total delay was estimated to be 37 days (IQR, 19-76). This was mostly due to health-seeking delay (median, 23 days; IQR, 8-53); in contrast, health facility diagnostic delay and treatment delay were relatively short (median, 1 day; IQR, 0-7; median, 1 day; IQR, 0-7, respectively). In 2021, health-seeking delay did not differ significantly between men and women but was shorter in children than in adults and shorter in clinically diagnosed than in bacteriologically confirmed TB cases. Health-seeking delay was longest in the East region (median, 44.5 days; IQR, 20-87) and shortest in Ulaanbaatar (median, 9; IQR, 14-64). TB treatment delay was similar across sexes, age groups and types of TB diagnosis but slightly longer among retreated cases and people living in Ulaanbaatar. Efforts to reduce TB transmission in Mongolia should prioritize decreasing delays in health seeking.

Tuberculosis Knowledge among Persons Living with HIV Attending a Tertiary Hospital in Lima, Peru

Tuberculosis (TB) is the leading cause of death among people living with HIV (PLWH). Limited TB knowledge has been associated with delayed TB diagnosis and low adherence to TB treatment. A cross-sectional study was conducted among PLWH at the largest HIV-referral center in Lima, Peru, to describe TB knowledge among PLWH and potential associated sociodemographic factors. Participants answered a self-administered survey on TB knowledge, which consisted of five questions about TB cure, transmission, treatment, symptoms, and prevention. Of 179 PLWH enrolled, most participants did not know that isoniazid (85%) and antiretrovirals (78%) are preventive measures for TB, and 56 (31.3%) knew that TB can be asymptomatic in PLWH. We did not find statistical differences in TB knowledge based on gender, education, marital status, and time on HIV care. We identified important gaps in TB knowledge among PLWH. Addressing these gaps could empower PLWH to reduce their TB risk.

Lessons learned from over a decade of data audits in international observational HIV cohorts in Latin America and East Africa

Introduction

Routine patient care data are increasingly used for biomedical research, but such "secondary use" data have known limitations, including their quality. When leveraging routine care data for observational research, developing audit protocols that can maximize informational return and minimize costs is paramount.

Methods

For more than a decade, the Latin America and East Africa regions of the International epidemiology Databases to Evaluate AIDS (IeDEA) consortium have been auditing the observational data drawn from participating human immunodeficiency virus clinics. Since our earliest audits, where external auditors used paper forms to record audit findings from paper medical records, we have streamlined our protocols to obtain more efficient and informative audits that keep up with advancing technology while reducing travel obligations and associated costs.

Results

We present five key lessons learned from conducting data audits of secondary-use data from resource-limited settings for more than 10 years and share eight recommendations for other consortia looking to implement data quality initiatives.

Conclusion

After completing multiple audit cycles in both the Latin America and East Africa regions of the IeDEA consortium, we have established a rich reference for data quality in our cohorts, as well as large, audited analytical datasets that can be used to answer important clinical questions with confidence. By sharing our audit processes and how they have been adapted over time, we hope that others can develop protocols informed by our lessons learned from more than a decade of experience in these large, diverse cohorts.

Are trajectories of depressive symptoms during the first half of drug-sensitive pulmonary tuberculosis treatment associated with loss to follow-up? A secondary analysis of longitudinal data

OBJECTIVE

The objective of this study was to identify trajectories of depressive symptoms (DSs) during the first half of drug-sensitive pulmonary tuberculosis (PTB) treatment and examine their association with loss to follow-up (LTFU) in the second half.

DESIGN

This study involved a secondary analysis of longitudinal data to identify potential trajectories of DS and their relationship with LTFU.

SETTING

The study was conducted in first and second-level health centres located in San Juan de Lurigancho, Lima, Peru.

PARTICIPANTS

Anonymised data from 265 individuals, including monthly measures of DSs from diagnosis to the completion of treatment, initiation of treatment for multidrug resistant TB, LTFU or death, were collected.

RESULTS

Three trajectories were identified: 'declining', 'growth' and 'high'. These trajectories were observed in 182 (68.7%), 53 (20%) and 30 (11.3%) of the 265 individuals, respectively, during the first half of PTB treatment. Compared with those with a 'declining' trajectory, individuals with a 'growth' trajectory had a higher likelihood of experiencing LTFU during the second half of PTB treatment, after controlling for sociodemographic factors and at least weekly alcohol use (OR 3.9; 95% CI 1.09 to 13.97, p=0.036).

CONCLUSIONS

The findings suggest that a trajectory of increasing DSs during the first half of PTB treatment is associated with a higher risk of LTFU during the second half.

Long-term impact on cardiopulmonary function and quality of life among patients recovered from SARS-CoV-2 infection in a 6-month follow-up period in Lima, Peru: FUNCTION cohort study protocol

INTRODUCTION

The sequelae of COVID-19 have been described as a multisystemic condition, with a great impact on the cardiovascular and pulmonary systems with abnormalities in pulmonary function tests, such as lower diffusing capacity of the lung for carbon monoxide (DLco) levels and pathological patterns in spirometry; persistence of radiological lesions; cardiac involvement such as myocarditis and pericarditis; and an increase in mental disorders such as anxiety and depression. Several factors, such as infection severity during the acute phase as well as vaccination status, have shown some variable effects on these post-COVID-19 conditions, mainly at a clinical level such as symptoms persistence. Longitudinal assessments and reversibility of changes across the spectrum of disease severity are required to understand the long-term impact of COVID-19.

METHODS AND ANALYSIS

A prospective cohort study aims to assess the impact of SARS-CoV-2 infection on cardiopulmonary function and quality of life after the acute phase of the disease over a 6-month follow-up period. Sample size was calculated to recruit 200 participants with confirmatory COVID-19 tests who will be subsequently classified according to infection severity. Four follow-up visits at baseline, month 1, month 3 and month 6 after discharge from the acute phase of the infection will be scheduled as well as procedures such as spirometry, DLco test, 6-minute walk test, chest CT scan, echocardiogram, ECG, N-terminal pro-B-type natriuretic peptide measurement and RAND-36 scale. Primary outcomes are defined as abnormal pulmonary function test considered as DLco <80%, abnormal cardiovascular function considered as left ventricular ejection fraction <50% and abnormal quality of life considered as a <40 score for each sphere in the RAND-36-Item Short Form Health Survey.

ETHICS AND DISSEMINATION

The study protocol was approved by the Institutional Ethics Committee of the Universidad Peruana Cayetano Heredia (SIDISI 203725) and the Ethics Committee of the Hospital Cayetano Heredia (042-2021). Protocol details were uploaded in ClinicalTrials.gov. Findings will be disseminated through peer-reviewed journals, scientific conferences and open-access social media platforms.

TRIAL REGISTRATION NUMBER

NCT05386485.

Isoniazid preventive therapy completion in children under 5 years old who are contacts of tuberculosis cases in Lima, Peru: study protocol for an open-label, cluster-randomized superiority trial

BACKGROUND

Children < 5 years old in contact with TB cases are at high risk for developing severe and fatal forms of TB. Contact investigation, BCG vaccination, and isoniazid preventive therapy (IPT) are the most effective strategies to prevent TB among children. However, the implementation of IPT faces challenges at several stages of the cascade of care of TB infection among children, particularly those less than 5 years old. In Peru, a large proportion of children do not complete IPT, which highlights the need to design effective interventions that enhance preventive therapy adherence and completion. Although the body of evidence for such interventions has grown, interventions in medium TB incidence settings are lacking. This study aims to test the effectiveness, acceptability, and feasibility of an intervention package to increase information and motivation to complete IPT among children < 5 who have been prescribed IPT.

METHODS

An open-label, cluster-randomized superiority trial will be conducted in two districts in South Lima, Peru. Thirty health facilities will be randomized as clusters, 10 to the intervention and 20 to control (standard of care). We aim to recruit 10 children from different households in each cluster. Participants will be caretakers of children aged < 5 years old who initiated IPT. The intervention consists of educational material, and short message services (SMS) reminders and motivators. The primary outcomes will be the proportion of children who picked up > 90% of the 24 weeks of IPT (22 pick-ups) and the proportion of children who picked up the 24 weeks of IPT. The standard of care is a weekly pick-up with monthly check-ups in a health facility. Feasibility and acceptability of the intervention will be assessed through an interview with the caretaker.

DISCUSSION

Unfavorable outcomes of TB in young children, high effectiveness of IPT, and low rates of IPT completion highlight the need to enhance adherence and completion of IPT among children < 5 years old. Testing of a context-adapted intervention is needed to improve IPT completion rates and therefore TB prevention in young children.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03881228. Registered on March 19, 2019.

Epidemiology of tuberculosis in Mongolia: analysis of surveillance data, 2015-2019

Mongolia has a high tuberculosis (TB) burden. Data from routine paper-based surveillance were used to describe the epidemiology of TB in Mongolia; the data included testing presumptive TB cases, TB notifications, drug-resistant cases, treatment outcomes and notifications in prisoners. The proportion of the population tested for TB increased between 2015 and 2019. The number and rate per 100 000 population of TB notifications decreased between 2015 and 2018 and then increased in 2019. Most TB notifications in 2019 were in the capital, Ulaanbaatar (59.3%), followed by the central (16.8%), Khangai (10.4%), east (8.5%) and west (5.0%) regions. About half of TB notifications nationally were bacteriologically confirmed (45.4% in 2015, 48.1% in 2019), with the proportion of bacteriologically confirmed TB per province or district varying from 0% to 66%. High TB notification rates were observed in 2019 for males aged 15-54 years (202 per 100 000
population) and females aged 15-34 years (190 per 100 000 population). Treatment success for all forms of TB was 90% in 2019 but was below the 90% target for bacteriologically confirmed cases. Between 2015 and 2019, the number of RR/MDR-TB notifications ranged from 265 to 211. The Mongolian National Tuberculosis Programme needs to continue its efforts in TB control, to further increase the programmatic impact and reduce the TB burden. It is recommended that Mongolia continue to increase TB screening, the use of Xpert testing, contact investigations and preventive treatments, and targeting interventions to the high-burden areas identified in this subnational analysis.

278. Long-term impact of pulmonary function among patients recovered from SARS-CoV-2 infection in Lima, Peru: a preliminary analysis of the FUNCTION cohort study

Background

Longitudinal assessment and reversibility of changes in the pulmonary function tests in the post-acute phase of COVID-19 across the whole spectrum of severity of infection is needed to understand the long-term burden of the disease.

Methods

This was a prospective cohort of symptomatic patients with a positive SARS-CoV-2 (molecular or antigenic) test. Participants were divided based on infection severity at baseline as mildly-ill (B1), moderately-ill (B2), severely-ill (B3), critically-ill (B4) (Fig.1). Follow-up consisted of 4 visits: within 7 days from discharge (BL), and at months 1 (M1), 3 (M3), and 6(M6). We report findings up to M3 for participants enrolled August 2021- March 2022. Pulmonary function capacity was assessed with carbon monoxide diffusing capacity (DLCO), spirometry, and 6-minute walk test (6MWT). A DLCO&lt; 80% was considered abnormal and reverted if &gt;80% at follow-up visits.

Study population divided by severity of infection

Results

Out of 206 eligible participants, 110 were enrolled, of which 96 (87%%), 79 (72%), and 52(47.2%) were evaluated at BL, M1, and M3, respectively (Fig.2). Most (67%) participants were male, median age was 37.5 years old (IQR: 28-46.3) and median body mass index was 26.7 (IQR:23.7-30.4). Regarding severity, 39 (41%) participants were classified as critically-ill (B4) at BL. No underlying comorbidities were reported among 63 (66%) participants, while diabetes type 2 (11%), asthma (7%) prior pulmonary tuberculosis (6%) and hypertension (5%) where the most frequent comorbidities overall; 17 (18%) reported smoking exposure. There were significant differences accross severity groups for sex, age, absence of comorbidities, and dyspnea during the acute phase of COVID-19 (Tab.1). At Of the 88 (92%) participants that underwent the pulmonary function tests at BL: 49 (56%) had DLCO &lt; 80% with a tendency to revert across B1-B4 groups at month 3 (Fig.3). Spirometry parameters (Forced Vital Capacity, Forced Expiratory Volume 1, Peak Expiratory Flow) and distance walked on 6MWT were different across groups.

Flowchart of the study population

Demographics of study population stratified by groups of severity

Median DLCO adjusted for hemoglobin value at baseline, month 1 and month 3 visits stratified by groups of severity of infection.

Conclusion

Abnormal DLCO tended to increase and revert to values greater than 80% in the 3-month follow-up period of patients recovered from SARS-CoV-2 infection across severity groups.

Disclosures

All Authors: No reported disclosures.

Drawings as tools to (re)imagine space in interdisciplinary global health research

Understanding the role of space in infectious diseases' dynamics in urban contexts is key to developing effective mitigation strategies. Urbanism, a discipline that both studies and acts upon the city, commonly uses drawings to analyze spatial patterns and their variables. This paper revisits drawings as analytical and integrative tools for interdisciplinary research. We introduce the use of drawings in two interdisciplinary projects conducted in the field of global public health: first, a study about the heterogeneous burden of tuberculosis and COVID-19 in Lima, Peru, and second, a study about urban malaria in Jimma, Ethiopia. In both cases, drawings such as maps, plans, and sections were used to analyze spatial factors present in the urban context at different scales: from the scale of the territory, the city, and the district, to the neighborhood and the household. We discuss the methodological approaches taken in both cases, considering the nature of the diseases being investigated as well as the natural and social context in which the studies took place. We contend that the use of drawings helps to reimagine space in public health research by adding a multidimensional perspective to spatial variables and contexts. The processes and products of drawing can help to (a) identify systemic relations within the spatial context, (b) facilitate integration of quantitative and qualitative data, and (c) guide the formulation of policy recommendations, informing public and urban health planning.

Lung cancer occurrence after an episode of tuberculosis: a systematic review and meta-analysis

INTRODUCTION

People with tuberculosis experience long-term health effects beyond cure, including chronic respiratory diseases. We investigated whether tuberculosis is a risk factor for subsequent lung cancer.

METHODS

We searched PubMed, Scopus, Cochrane, Latin American and Caribbean Health Sciences Literature and the Scientific Electronic Library Online for cohort and case-control studies providing effect estimates for the association between tuberculosis and subsequent lung cancer. We pooled estimates through random-effects meta-analysis. The study was registered in PROSPERO (CDR42020178362).

RESULTS

Out of 6240 records, we included 29 cohort and 44 case-control studies. Pooled estimates adjusted for age and smoking (assessed quantitatively) were hazard ratio (HR) 1.51 (95% CI 1.30-1.76, I²=81%; five studies) and OR 1.74 (95% CI 1.42-2.13, I²=59%; 19 studies). The occurrence of lung cancer was increased for 2 years after tuberculosis diagnosis (HR 5.01, 95% CI 3.64-6.89; two studies), but decreased thereafter. Most studies were retrospective, had moderate to high risk of bias, and did not control for passive smoking, environmental exposure and socioeconomic status. Heterogeneity was high.

CONCLUSION

We document an association between tuberculosis and lung cancer occurrence, particularly in, but not limited to, the first 2 years after tuberculosis diagnosis. Some cancer cases may have been present at the time of tuberculosis diagnosis and therefore causality cannot be ascertained. Prospective studies controlling for key confounding factors are needed to identify which tuberculosis patients are at the highest risk, as well as cost-effective approaches to mitigate such risk.

Integrating services for HIV and multidrug-resistant tuberculosis: A global cross-sectional survey among ART clinics in low- and middle-income countries

Tuberculosis (TB) is the leading cause of death among PLHIV and multidrug-resistant-TB (MDR-TB) is associated with high mortality. We examined the management for adult PLHIV coinfected with MDR-TB at ART clinics in lower income countries. Between 2019 and 2020, we conducted a cross-sectional survey at 29 ART clinics in high TB burden countries within the global IeDEA network. We used structured questionnaires to collect clinic-level data on the TB and HIV services and the availability of diagnostic tools and treatment for MDR-TB. Of 29 ART clinics, 25 (86%) were in urban areas and 19 (66%) were tertiary care clinics. Integrated HIV-TB services were reported at 25 (86%) ART clinics for pan-susceptible TB, and 14 (48%) clinics reported full MDR-TB services on-site, i.e. drug susceptibility testing [DST] and MDR-TB treatment. Some form of DST was available on-site at 22 (76%) clinics, while the remainder referred testing off-site. On-site DST for second-line drugs was available at 9 (31%) clinics. MDR-TB treatment was delivered on-site at 15 (52%) clinics, with 10 individualizing treatment based on DST results and five using standardized regimens alone. Bedaquiline was routinely available at 5 (17%) clinics and delamanid at 3 (10%) clinics. Although most ART clinics reported having integrated HIV and TB services, few had fully integrated MDR-TB services. There is a continued need for increased access to diagnostic and treatment options for MDR-TB patients and better integration of MDR-TB services into the HIV care continuum.

Clinical characteristics of vulnerable populations hospitalized and diagnosed with COVID-19 in Buenos Aires, Argentina

There is not in Argentina publications regarding the presentation of patients with COVID-19 requiring hospitalized and emergency care in vulnerable populations (lower incomes and less education tend at greater risk for poor health status and healthcare access), and it has few reports in developing countries. The objective is to determine whether in the care of vulnerable patients, to succeed against COVID-19, multiple public health tools and interventions will be needed to minimize morbidity and mortality. The study is a prospective cohort investigation of patients with lab-confirmed COVID-19, who required to any of the Health Centers response from April 8, 2020, to August 18, 2020. In Buenos Aires Metropolitan Area (AMBA), April 8, 2020 the virus was identified in patients hospitalized in the "Southeast Network" (SN), AMBA. SN covering an area of 661 square kilometers, with 1.8 million inhabitants residing in urban, and rural areas. A total of 14 health centers with different levels of care complexity provide care to patients in the region. The information of each patient with COVID-19 evaluated by SN, was incorporated in an Epidemiological Dashboard. The investigation was designed and reported with consideration of observational studies in epidemiology. We describe the hospitals presentation and care of persons who required SN response and were ultimately diagnosed with COVID-19. From April 8, 2020, to August 18, 2020, were included 1495 patients with lab-confirmed COVID-19 in SN. A total of 58% patients were men, and the mean age (SD) was 48.9 (15.59) years. Eighty one percent patients with pre-existing diseases, most frequent hypertension and diabetes, but hypertension, chronic lung disease, and cardiovascular disease presented higher risk. A total of 13% were hospitalized in Intensive Therapy Unit. The mortality of the cohort was 9.77%. Mortality was higher for patients aged 65 or more (OR 5.09), and for those had some pre-existing disease (OR 2.61). Our observations are consistent with reports demonstrating older persons, and those with comorbidities have the highest risk of mortality related to COVID-19. However, unlike other reports from developed or some developing countries, the mortality in our study is lower. This finding may be related to age of our cohort is younger than other published. Also, the health system was able to respond to the demand.

Recurrent TB: a systematic review and meta-analysis of the incidence rates and the proportions of relapses and reinfections

BACKGROUND

A recurrent tuberculosis (TB) episode results from exogenous reinfection or relapse after cure. The use of genotyping allows the distinction between both.

METHODS

We did a systematic review and meta-analysis, using four databases to search for studies in English, French and Spanish published between 1 January 1980 and 30 September 2020 that assessed recurrences after TB treatment success and/or differentiated relapses from reinfections using genotyping. We calculated person years of follow-up and performed random-effects model meta-analysis for estimating pooled recurrent TB incidence rates and proportions of relapses and reinfections. We performed subgroup analyses by clinical-epidemiological factors and by methodological study characteristics.

FINDINGS

The pooled recurrent TB incidence rate was 2.26 per 100 person years at risk (95% CI 1.87 to 2.73; 145 studies). Heterogeneity was high (I²=98%). Stratified pooled recurrence rates increased from 1.47 (95% CI 0.87 to 2.46) to 4.10 (95% CI 2.67 to 6.28) per 100 person years for studies conducted in low versus high TB incidence settings. Background HIV prevalence, treatment drug regimen, sample size and duration of follow-up contributed too. The pooled proportion of relapses was 70% (95% CI 63% to 77%; I²=85%; 48 studies). Heterogeneity was determined by background TB incidence, as demonstrated by pooled proportions of 83% (95% CI 75% to 89%) versus 59% (95% CI 42% to 74%) relapse for studies from settings with low versus high TB incidence, respectively.

INTERPRETATION

The risk of recurrent TB is substantial and relapse is consistently the most frequent form of recurrence. Notwithstanding, with increasing background TB incidence the proportion of reinfections increases and the predominance of relapses among recurrences decreases.

PROSPERO REGISTRATION NUMBER

CRD42018077867.

Contact evaluation and isoniazid preventive therapy among close and household contacts of tuberculosis patients in Lima, Peru: an analysis of routine data

OBJECTIVE

Contacts of pulmonary tuberculosis (TB) cases are at high risk of TB infection and progression to disease. Close and household contacts and those <5 years old have the highest risk. Isoniazid preventive therapy (IPT) can largely prevent TB disease among infected individuals. International and Peruvian recommendations include TB contact investigation and IPT prescription to eligible contacts. We conducted a study in Lima, Peru, to determine the number of close and household contacts who were evaluated, started on IPT, and who completed it, and the factors associated to compliance with national guidelines.

METHODS

We conducted a longitudinal retrospective study including all TB cases diagnosed between January 2015 and July 2016 in 13 health facilities in south Lima. Treatment cards, TB registers and clinical files were reviewed and data on index cases (sex, age, smear status, TB treatment outcome), contact investigation (sex, age, kinship to the index case, evaluations at month 0, 2 and 6) and health facility (number of TB cases notified per year, proportion of TB cases with treatment success) were extracted. We tabulated frequencies of contact evaluation by contact and index case characteristics. To investigate determinants of IPT initiation and completion, we used generalised linear mixed models.

RESULTS

A total of 2323 contacts were reported by 662 index cases; the median number of contacts per case was four (IQR, 2-5). Evaluation at month 0 was completed by 99.2% (255/257) of contacts <5 and 98.1% (558/569) of contacts aged 5-19 years. Of 191 eligible contacts <5 years old, 70.2% (134) started IPT and 31.4% (42) completed it. Of 395 contacts 5-19 years old, 36.7% (145) started IPT and 32.4% (47) completed it. Factors associated to not starting IPT among contacts <5 years old were being a second-degree relative to the index case (OR 6.6 95CI% 2.6-16.5), not having received a tuberculin skin test (TST) (OR 3.9 95%CI 1.4-10.8), being contact of a smear-negative index case (OR 5.5 95%CI 2.0-15.1) and attending a low-caseload health facility (OR 2.8 95%CI 1.3-6.2). Factors associated to not starting IPT among 5-19 year-olds were age (OR 13.7 95%CI 5.9-32.0 for 16-19 vs. 5-7 years old), being a second-degree relative (OR 3.0 95%CI 1.6-5.6), not having received a TST (OR 5.4, 95%CI 2.5-11.8), being contact of a male index case (OR 2.1 95CI% 1.2-3.5), with smear-negative TB (OR 1.9 95%CI 1.0-3.6), and attending a high-caseload health facility (OR 2.1 95%CI 1.2-3.6). Factors associated to not completing IPT, among contacts who started, were not having received a TST (OR 3.4 95%CI 1.5-7.9 for <5 year-olds, and OR 4.3 95%CI 1.7-10.8 for those 5-19 years old), being contact of an index case with TB treatment outcome other than success (OR 9.3 95%CI 2.6-33.8 for <5 year-olds and OR 15.3 95%CI 1.9-125.8 for those 5-19 years old), and, only for those 5-19 years old, attending a health facility with high caseload (OR 3.2 95%CI 1.4-7.7) and a health facility with low proportion of TB cases with treatment success (OR 4.4 95%CI 1.9-10.2).

CONCLUSIONS

We found partial compliance to TB contact investigation, and identified contact, index case and health facility-related factors associated to IPT start and completion that can guide the TB programme in increasing coverage and quality of this fundamental activity.

Variations in AXIN2 predict risk and prognosis of colorectal cancer

Objective

Colorectal cancer (CRC) and hypodontia are frequent and different diseases with common genes are involved in their etiology. The objective of this study was to identify the association between AXIN2 rs2240308 with hypodontia and CRC.

Patients and methods

This study consisted of 50 individuals with hypodontia, 50 individuals with CRC, and 155 healthy individuals from Colombia. SNP genotyping assays of rs2240308 were performed and family history of cancer in individuals with hypodontia was documented. In silico analysis was implemented to define the genomic profile of the AXIN2 gene associated with CRC. Multivariate analysis, chi square, odd ratio tests, and R software were used for statistical analysis.

Results

AXIN2 rs2240308 showed association with CRC (OR = 5.4 CI: 2.7–10.4; p < 0.001) and with other familial cancer in individuals with hypodontia (p < 0.005 OR = 1.75, 95% CI: 1.22–6.91). In silico analysis showed that variations in AXIN2 found in CRC patients, were more frequently in earlier stages of tumor and patients who carry variations in the AXIN2 gene have a worse prognosis (p < 0.05). The association between AXIN2 rs2240308 with hypodontia was not significant.

Conclusions

These results suggest that AXIN2 rs2240308 polymorphism is associated with CRC and AXIN2 could be a risk marker for predisposition and prognosis of CRC.

Mycobacterium tuberculosis-specific cytokine biomarkers for the diagnosis of childhood TB in a TB-endemic setting

The tuberculin skin test and interferon-gamma release assays have limitations in diagnosing tuberculosis (TB), particularly in children. This study investigated the performance of candidate M. tuberculosis-specific cytokine biomarkers for TB in children in a TB-endemic setting. A total of 237 children with a household contact with smear-positive pulmonary TB were recruited. Importantly, a group of children with illnesses other than TB (sick controls) was included to assess specificity.

Median IFN-ɣ, IL-1ra, IL-2, IL-13, IP-10, MIP-1β and TNF-α responses were significantly higher in children with active TB and latent TB infection (LTBI) than in both healthy and sick control children. Three of these cytokines – IL-2, IL-13 and IP-10 – showed better performance characteristics than IFN-ɣ, with IL-2 achieving positive and negative predictive values of 97.7% and 90.7%, respectively. Furthermore, IL-1ra and TNF-α responses differed significantly between active TB and LTBI cases, suggesting that they may be stage-specific biomarkers.

Our data indicate that incorporating these biomarkers into future blood-based TB assays could result in substantial performance gains.

Health literacy and knowledge related to tuberculosis among outpatients at a referral hospital in Lima, Peru

BACKGROUND

Tuberculosis (TB) case detection in Peru relies on passive case finding. This strategy relies on the assumption that the community is aware that a persistent cough or contact with a TB patient is an indication to seek formal health care. This study evaluated health literacy and TB knowledge among outpatients at Hospital Cayetano Heredia in Lima, Peru.

METHODS

A cross-sectional survey was performed between June and August 2017. Data on sociodemographic factors, TB knowledge, and health literacy were collected, and bivariate and multivariate logistic regressions were performed to study the associations between variables.

RESULTS

The analysis included 272 participants; 57.7% knew someone who had TB and 9% had TB in the past. A 2-week cough was reported as a TB symptom by 66 (24%) participants. High TB knowledge was found among 149 (54.8%) participants and high health literacy was found among 193 (71.0%) participants. Health literacy and TB knowledge were not significantly associated (OR=0.9; 95% CI 0.5-1.5). After controlling for sex, age, district, education, health insurance, frequency of hospital visits, and previous TB diagnosis, high TB knowledge was associated with knowing someone with TB (aOR=2.7; 95% CI 1.6-4.7) and inversely associated with being a public transport driver (aOR=0.2; 95% CI 0.05-0.9). Not living in poverty was the single factor associated with high health literacy (aOR=3.8; 95% CI 1.6-8.9).

CONCLUSION

Although TB knowledge was fair, 30% did not know that cough is a symptom of TB and >70% did not know being in contact with a TB patient is a risk factor for TB. Tailoring educational strategies to at-risk groups may enhance passive case detection especially among transport workers and TB contacts in Lima, Peru.

Patient-nominated supporters as facilitators for engagement in HIV care in a referral hospital in Peru: A retrospective cohort study

Patient-nominated supporters can potentially improve the continuum of HIV care. We retrospectively determined factors associated with having a patient-nominated supporter among people living with HIV (PLWH), and its association with retention in care and viral suppression. We analysed registries of adults evaluated by social workers (n = 1345) at a referral hospital in Peru between 2011–2014. Nondisclosure of HIV status was associated with lacking supporters (aPR: 5.41, 95% CI: 3.83–7.64). Retention in care was 76.4% and 34.2% after one and two years of enrolment, respectively. PLWH with supporters were more likely to be retained in care after two years (aRR = 1.36, 95% CI: 1.02–1.81), but not after one year (aRR = 1.10, 95% CI: 0.98–1.23) compared to PLWH without supporters. Having supporters who were parents or friends was associated with an increased probability of being retained in care after one and two years of enrolment. Viral suppression after one year of enrolment was 58.7%. Having a supporter was not associated with viral suppression (aRR = 1.18, 95% CI: 0.99–1.41), but PLWH with supporters were more likely to have viral load measurements (p = 0.005). Patient-nominated supporters appear beneficial for engagement in HIV care; these benefits may be related to the nature of their relationship with PLWH.

HIV screening among newly diagnosed TB patients: a cross sectional study in Lima, Peru

Background

Since 2006, the Peruvian National TB program (NTP) recommends voluntary counseling and testing (VCT) for all tuberculosis (TB) patients. Responding to the differential burden of both diseases in Peru, TB is managed in peripheral health facilities while HIV is managed in referral centers. This study aims to determine the coverage of HIV screening among TB patients and the characteristics of persons not screened.

Methods

From March 2010 to December 2011 we enrolled new smear-positive pulmonary TB adults in 34 health facilities in a district in Lima. NTP staff offered VCT to all TB patients. Patients with an HIV positive result were referred for confirmation tests and management. We interviewed patients to collect their demographic and clinical characteristics and registered if patients opted in or out of the screening.

Results

Of the 1295 enrolled TB patients, nine had a known HIV diagnosis. Of the remaining, 76.1% (979) were screened for HIV. Among the 23.9% (307) not screened, 38.4% (118) opted out of the screening. TB patients at one of the health care facilities of the higher areas of the district (OR = 3.38, CI 95% 2.17–5.28 for the highest area and OR = 2.82, CI 95% 1.78–4.49 for the high area) as well as those reporting illegal drug consumption (OR = 1.65, CI 95% 1.15–2.37) were more likely not to be screened. Twenty-four were HIV positive (1.9% of all patients 1295, or 2.4% of those screened). Of 15 patients diagnosed with HIV during the TB episode, ten were enrolled in an HIV program. The median time between the result of the HIV screening and the first consultation at the HIV program was 82 days (IQR, 32–414). The median time between the result of the HIV screening and antiretroviral initiation was 148.5 days (IQR 32–500).

Conclusions

An acceptable proportion of TB patients were screened for HIV in Lima. Referral systems of HIV positive patients should be strengthened for timely ART initiation.

Improving Appointment Adherence among Young Adults with HIV in Peru with an mHealth Intervention: a Feasibility Study

Background

Mobile Health (mHealth) interventions, including short message services (SMS) reminders and motivational messages, are associated with improved HIV appointment adherence, though feasibility is context-dependent. We assessed the feasibility of an mHealth intervention to improve appointment adherence among young adults with HIV in Lima, Peru.

Methods

Between November 2016 and April 2017, we implemented a one-way mHealth pilot intervention in an outpatient hospital without electronic medical records. We enrolled young adults (age 18–29) entering HIV care in a 3-component intervention: (i) reminder SMS prior to scheduled appointments (provider, laboratory, pharmacy); (ii) motivational SMS after each visit; and (iii) phone call following a missed visit. Feasibility evaluation included enrollment acceptance, visit tracking (information captured in the study database within 3 days of attendance), and proportion of intervention delivery (threshold &gt;90%). We performed a qualitative assessment to identify implementation challenges reviewing staff field notes and meeting minutes.

Results

We enrolled 80/94 (85.1%) eligible participants. The median age was 25 years and 83% were male. The median time of follow-up after enrollment was 115 [interquartile range (IQR): 84–141] days, and participants had a median of 10 (IQR: 8–14) visits during the study period. Among 850 total participant visits, study personnel tracked 751 (88.4%); most (80.8%) untracked visits were pharmacy pickups. Of all tracked visits, most (78.7%) were scheduled appointments and 160 (21.3%) were unscheduled walk-ins. Intervention delivery reached 556/591 (94.1%) for reminder SMS; 733/751 (97.6%) for motivational messages, and 169/170 (99.4%) phone calls for missed visits, 127 (75.1%) of which were answered. Qualitative assessment revealed 2 major themes: real-time appointment tracking in a paper-based system consumed most staff time and resources, and meticulous in-person coordination between the implementation and hospital staff was essential for tracking.

Conclusion

An mHealth intervention to improve appointment adherence among young adults with HIV in Peru appears feasible with dedicated staff and a reliable appointment tracking system. Digitalized appointment systems may be needed to address challenges for scale-up.

Disclosures

All authors: No reported disclosures.

Mycobacterium tuberculosis lineage 4 comprises globally distributed and geographically restricted sublineages

Generalist and specialist species differ in the breadth of their ecological niches. Little is known about the niche width of obligate human pathogens. Here we analyzed a global collection of Mycobacterium tuberculosis lineage 4 clinical isolates, the most geographically widespread cause of human tuberculosis. We show that lineage 4 comprises globally distributed and geographically restricted sublineages, suggesting a distinction between generalists and specialists. Population genomic analyses showed that, whereas the majority of human T cell epitopes were conserved in all sublineages, the proportion of variable epitopes was higher in generalists. Our data further support a European origin for the most common generalist sublineage. Hence, the global success of lineage 4 reflects distinct strategies adopted by different sublineages and the influence of human migration.

A prospective longitudinal study of tuberculosis among household contacts of smear-positive tuberculosis cases in Lima, Peru

Background

Household contacts (HHCs) of TB cases are at increased risk for TB disease compared to the general population but the risk may be modified by individual or household factors. We conducted a study to determine incident TB among HHCs over two years after exposure and to identify individual and household level risk factors.

Methods

Adults newly diagnosed with a first episode of smear-positive pulmonary TB (index cases) between March 2010 and December 2011 in eastern Lima, were interviewed to identify their HHC and household characteristics. TB registers were reviewed for up to two years after the index case diagnosis and house visits were made to ascertain TB cases among HHC. The TB incidence rate ratio among HHCs as a function of risk factors was determined using generalized linear mixed models.

Results

The 1178 index cases reported 5466 HHCs. In 402/1178 (34.1 %) households, at least one HHC had experienced a TB episode ever. The TB incidence among HHCs was 1918 (95%CI 1669–2194) per 100,000 person-years overall, and was 2392 (95%CI 2005–2833) and 1435 (95%CI 1139–1787) per 100,000 person-years in the first and second year, respectively. Incident TB occurred more than six months following the index case’s TB diagnosis in 121/205 (59.0 %) HHCs. In HHCs, bacillary load and time between symptoms and treatment initiation in the index case, as well as the relationship to the index case and the sex of the HHC all had a significant association with TB incidence in HHCs.

Conclusions

Incidence of TB among HHCs was more than ten times higher than in the general population. Certain HHC and households were at higher risk of TB, we recommend studies to compare HHC investigation to households at highest risk versus current practice, in terms of efficiency.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1616-x) contains supplementary material, which is available to authorized users.

Prevalence, Risk Factors, and Treatment Outcomes of Isoniazid- and Rifampicin-Mono-Resistant Pulmonary Tuberculosis in Lima, Peru

Background

Isoniazid and rifampicin are the two most efficacious first-line agents for tuberculosis (TB) treatment. We assessed the prevalence of isoniazid and rifampicin mono-resistance, associated risk factors, and the association of mono-resistance on treatment outcomes.

Methods

A prospective, observational cohort study enrolled adults with a first episode of smear-positive pulmonary TB from 34 health facilities in a northern district of Lima, Peru, from March 2010 through December 2011. Participants were interviewed and a sputum sample was cultured on Löwenstein-Jensen (LJ) media. Drug susceptibility testing was performed using the proportion method. Medication regimens were documented for each patient. Our primary outcomes were treatment outcome at the end of treatment. The secondary outcome included recurrent episodes among cured patients within two years after completion of the treatment.

Results

Of 1292 patients enrolled, 1039 (80%) were culture-positive. From this subpopulation, isoniazid mono-resistance was present in 85 (8%) patients and rifampicin mono-resistance was present in 24 (2%) patients. In the multivariate logistic regression model, isoniazid mono-resistance was associated with illicit drug use (adjusted odds ratio (aOR) = 2.10; 95% confidence interval (CI): 1.1–4.1), and rifampicin mono-resistance was associated with HIV infection (aOR = 9.43; 95%CI: 1.9–47.8). Isoniazid mono-resistant patients had a higher risk of poor treatment outcomes including treatment failure (2/85, 2%, p-value<0.01) and death (4/85, 5%, p<0.02). Rifampicin mono-resistant patients had a higher risk of death (2/24, 8%, p<0.01).

Conclusion

A high prevalence of isoniazid and rifampicin mono-resistance was found among TB patients in our low HIV burden setting which were similar to regions with high HIV burden. Patients with isoniazid and rifampicin mono-resistance had an increased risk of poor treatment outcomes.

Implementation of a stepped-wedge cluster randomized design in routine public health practice: design and application for a tuberculosis (TB) household contact study in a high burden area of Lima, Peru

Background

We designed a pragmatic stepped-wedge cluster randomized controlled trial in order to evaluate provider-initiated evaluation of household contacts (HCs) of smear positive tuberculosis (TB) cases within a routine TB program in Lima, Peru.

Methods/Design

National TB program (NTP) officers of San Juan de Lurigancho District (Lima, Peru) and university-based researchers jointly designed a pragmatic stepped-wedge cluster randomized trial design in order to evaluate a planned active case finding (ACF) program for all HCs of smear-positive TB cases in 34 district healthcare centres. Randomization of time to intervention initiation was stratified by health centre TB case rate. The ACF intervention included provider-initiated home visits of all new sputum smear positive TB patients in order to evaluate household contacts for active TB. Active TB was diagnosed using symptom screening, sputum screening, chest x-ray and clinical evaluation. Once initiated, ACF was provided by NTP staff and integrated into the routine DOTS TB program activities.

Discussion

This study protocol describes the pragmatic stepped-wedge cluster randomized trial of active household contact evaluations within an NTP. The stepped-wedge design met overlapping needs of local TB programmers and researchers to adequately evaluate the large-scale roll out of a new control program in a TB endemic setting. Multiple planning meetings were required to develop the necessary networks and in order to understand the operations, needs and goals of the NTP staff and researchers collaborating on this project. The advantages and challenges of using this study design in practice and within existing routine TB programs in a middle-income country context are discussed.

Trial registration

ClinicalTrials.gov NCT02174380. Registered 24 Jun 2014

Patient Characteristics Associated with Tuberculosis Treatment Default: A Cohort Study in a High-Incidence Area of Lima, Peru

Background

Although tuberculosis (TB) is usually curable with antibiotics, poor adherence to medication can lead to increased transmission, drug resistance, and death. Prior research has shown several factors to be associated with poor adherence, but this problem remains a substantial barrier to global TB control. We studied patients in a high-incidence district of Lima, Peru to identify factors associated with premature termination of treatment (treatment default).

Methods

We conducted a prospective cohort study of adult smear-positive TB patients enrolled between January 2010 and December 2011 with no history of TB disease. Descriptive statistics and multivariable logistic regression analyses were performed to determine risk factors associated with treatment default.

Results

Of the 1233 patients studied, 127 (10%) defaulted from treatment. Patients who defaulted were more likely to have used illegal drugs (OR = 4.78, 95% CI: 3.05-7.49), have multidrug-resistant TB (OR = 3.04, 95% CI: 1.58-5.85), not have been tested for HIV (OR = 2.30, 95% CI: 1.50-3.54), drink alcohol at least weekly (OR = 2.22, 95% CI: 1.40-3.52), be underweight (OR = 2.08, 95% CI: 1.21-3.56), or not have completed secondary education (OR = 1.55, 95% CI: 1.03-2.33).

Conclusions

Our study identified several factors associated with defaulting from treatment, suggesting a complex set of causes that might lead to default. Addressing these factors individually would be difficult, but they might help to identify certain high-risk patients for supplemental intervention prior to treatment interruption. Treatment adherence remains a barrier to successful TB care and reducing the frequency of default is important for both the patients’ health and the health of the community.

Time to initiation of multidrug-resistant tuberculosis treatment and its relation with outcome in a high incidence district in Lima, Peru

OBJECTIVE

To determine the time from diagnosis to start of multidrug resistant tuberculosis (MDR TB) treatment in Lima, Peru.

METHODS

We studied new smear-positive TB adults that were started on MDR TB treatment or that were switched to it between June 2008 and December 2011.

RESULTS

Time from the first positive smear to MDR-TB treatment was >30 days in 35% (13/37) of patients. Among the 27% (24/88) of patients that switched to MDR-TB treatment, time from the last dose of a drug-susceptible regimen was >30 days.

CONCLUSION

Start of and switching to MDR TB treatment is still delayed.

Association of major depressive episode with negative outcomes of tuberculosis treatment

BACKGROUND

Pulmonary tuberculosis (TB) persists an important contributor to the burden of diseases in developing countries. TB control success is based on the patient's compliance to the treatment. Depressive disorders have been negatively associated with compliance of therapeutic schemes for chronic diseases. This study aimed to estimate the significance and magnitude of major depressive episode as a hazard factor for negative outcomes (NO), including abandon or death in patients receiving TB treatment.

METHODOLOGY/PRINCIPAL FINDINGS

A longitudinal study was conducted to evaluate the association of major depressive episode (MDE), as measured by a 5-item version of the Center for Epidemiological Studies Depression Scale (CES-D) with NO to TB treatment. Patients with confirmed TB were enrolled before the start of TB treatment. Baseline measurements included socio-demographic variables as well as the CES-D, which was also applied every month until the end of the treatment. Death and treatment default were assessed monthly. Survivor function (SF) for NO according to MDE status (CES-D≥6) at baseline (MDEb) was estimated. Cox's Regression was performed for bivariate analyses as well as for the multivariate model. A total of 325 patients accepted to participate in the study, of which 34 where excluded for diagnosis of MDR-TB. NO was observed in 24 patients (8.2%); 109 (37%) presented MDEb. Statistically significant difference was found on the SF of patients with and without MDEb (0.85 vs. 0.96, p-value = 0.002). The hazard ratio for NO, controlled for age, sex, marital status and instruction level was 3.54 (95%CI 1.43-8.75; p-value = 0.006).

CONCLUSION

The presence of MDE at baseline is associated to NO of TB treatment. Targeting detection and treatment of MDE may improve TB treatment outcomes.

Charge separation in donor-acceptor spiro compounds at metal and metal oxide surfaces investigated by surface photovoltage

Molecules with donor (diphenylamine) and acceptor moieties (dicyano or cyanoacrylic acid moieties) were linked by fluorene or spirobisfluorene cores and the chain length has been changed by introducing a thiophene group between fluorene and diphenylamine. Four different kinds of fluorene and spirobisfluorene compounds were adsorbed from highly diluted solutions at ultra-thin nanoporous TiO2 (np-TiO2), Au and ITO surfaces. Charge separation has been investigated by surface photovoltage spectroscopy in the fixed capacitor and Kelvin probe arrangements in vacuum. Striking differences between the interaction of linking (dicyano or cyanoacrylic moieties) and different substrates were observed. Intra-molecular charge separation and electron injection have been distinguished and the directed adsorption of spiro compounds was deduced.

Endogenous neurogenesis after intracerebral hemorrhage

Currently, it is accepted that brain injury promotes endogenous neurogenesis in mammals, primarily in the subventricular zone (SVZ), and newborn cells can migrate to the injured area. We examined the pattern of endogenous neurogenesis in adult rats after intracerebral hemorrhage (ICH) that was caused by intrastrial administration of collagenase type IV. Our results showed that ICH induced strong endogenous neurogenesis between 72 hours and 7 days after injury, but that the majority of newborn cells did not survive longer than 3 weeks due to apoptosis-mediated cell death. Furthermore, endogenous neurogenesis remained into a small extent at least 1 year after ICH. Because of the growing interest in new strategies for brain regeneration, these data suggest endogenous neurogenesis and inhibiting apoptosis of newborn neuroblasts as potential strategies to improve the consequences of hemorrhagic stroke in humans.

High prevalence of primary multidrug resistant tuberculosis in persons with no known risk factors

Introduction

In high multidrug resistant (MDR) tuberculosis (TB) prevalence areas, drug susceptibility testing (DST) at diagnosis is recommended for patients with risk factors for MDR. However, this approach might miss a substantial proportion of MDR-TB in the general population. We studied primary MDR in patients considered to be at low risk of MDR-TB in Lima, Peru.

Methods

We enrolled new sputum smear-positive TB patients who did not report any MDR-TB risk factor: known exposure to a TB patient whose treatment failed or who died or who was known to have MDR-TB; immunosuppressive co-morbidities, ex prison inmates; prison and health care workers; and alcohol or drug abuse. A structured questionnaire was applied to all enrolled participants to confirm the absence of these factors and thus minimize underreporting. Sputum from all participants was cultured on Löwenstein-Jensen media and DST for first line drugs was performed using the 7H10 agar method.

Results

Of 875 participants with complete data, 23.2% (203) had risk factors for MDR-TB elicited after enrolment. Among the group with no reported risk factors who had a positive culture, we found a 6.3% (95%CI 4.4–8.3) (37/584) rate of MDR-TB. In this group no epidemiological characteristics were associated with MDR-TB. Thus, in this group, multidrug resistance occurred in patients with no identifiable risk factors.

Conclusions

We found a high rate of primary MDR-TB in a general population with no identifiable risk factors for MDR-TB. This suggests that in a high endemic area targeting patients for MDR-TB based on the presence of risk factors is an insufficient intervention.

Quality assessment of smear microscopy by stratified lot sampling of treatment follow-up slides

SETTING

Ten peripheral laboratories performing routine acid-fast bacilli (AFB) smear microscopy in Lima, Peru.

OBJECTIVES

To test whether external quality assessment (EQA) rechecking of AFB smears becomes more efficient with stratified lot sampling of treatment follow-up smears.

DESIGN

In 2 consecutive years, a stratified lot sample of 36 treatment follow-up slides and 24 diagnostic slides were randomly selected and blindly rechecked. A second controller determined the final result for discordant slides. Feedback was provided to laboratory technicians during supervisory visits.

RESULTS

More false-negative errors were found in the follow-up slides than in the tuberculosis suspect slides: 25 vs. 3. This represented a yield of 3.5% in 720 follow-up slides and only 0.6% in 480 diagnostic slides. Positive predictive values were high in both years. Respectively three and eight laboratories did not reach a relative sensitivity of >65% during the first and second year, and a clear improvement was seen in only one laboratory. Excessive workload seemed to preclude raising the level of routine performance.

CONCLUSIONS

EQA with stratified lot sampling of treatment follow-up slides proved very efficient and effective for identifying laboratories with substandard performance in a setting with low positivity rates in routine diagnostic smears.