Availability of drugs and resistance testing for BPaLM regimen for rifampicin-resistant tuberculosis in Europe

OBJECTIVES

Multidrug-resistant/Rifampicin-resistant tuberculosis (TB) is a major obstacle to successful TB control. The recommendation by the World Health Organization to use bedaquiline, pretomanid, linezolid and moxifloxacin (BPaL(M)) for 6 months, based on results of three trials with high efficacy and low toxicity, has revolutionized treatment options.

METHODS

In this study, representatives of the Tuberculosis Network European Trialsgroup (TBnet) in 44/54 countries of the WHO Europe region document the availability of the medicines and drug susceptibility testing (DST) of the BPaL(M) regimen through a structured questionnaire between September to November 2023.

RESULTS

24/44 (54.5%), 42/44 (95.5%), 43/44 (97.7%), and 43/44 (97.7%) had access to pretomanid, bedaquiline, linezolid, and moxifloxacin, respectively. Overall, 23/44 (52.3%) had access to all the drugs composing the BPaL(M) regimen. 7/44 (15.9%), 28/44 (63.6%), 34/44 (77.3%) and 36/44 (81.8%) had access to DST for pretomanid, bedaquiline, linezolid and moxifloxacin, respectively. DST was available for all medicines composing the BPaL(M) regimen in 6/44 (13.6%) countries.

CONCLUSION

Only in about half of the countries participating in the survey clinicians have access to all the BPaL(M) regimen drugs. In less than a fifth of countries, a complete DST is possible. Rapid scale up of DST capacity to prevent unnoticed spread of drug resistance and equal access to new regimens are urgently needed in Europe.

Ventriculostomy-associated infection (VAI) in patients with acute brain injury-a retrospective study

BACKGROUND

Ventriculostomy-associated infection (VAI) is common after external ventricular drains (EVD) insertion but is difficult to diagnose in patients with acute brain injury. Previously, we proposed a set of criteria for ruling out VAI in traumatic brain injury. This study aimed to validate these criteria. For exploratory purposes, we sought to develop and validate a score for VAI risk assessment in patients with different types of severe acute brain injury.

METHODS

This retrospective cohort study included adults with acute brain injury who received an EVD and in whom CSF samples were taken over a period of 57 months. As standard non-coated bolt-connected EVDs were used. The predictive performance of biomarkers was analyzed as defined previously. A multivariable regression model was performed with five variables.

RESULTS

A total of 683 patients with acute brain injury underwent EVD placement and had 1272 CSF samples; 92 (13.5%) patients were categorized as culture-positive VAI, 130 (19%) as culture-negative VAI, and 461 (67.5%) as no VAI. A low CSF WBC/RBC ratio (< 0.037), high CSF/plasma glucose ratio (> 0.6), and low CSF protein (< 0.5g/L) showed a positive predictive value of 0.09 (95%CI, 0.05-0.13). In the multivariable logistic regression model, days to sample (OR 1.09; 95%CI, 1.03-1.16) and CSF WBC/RBC ratio (OR 34.86; 95%CI, 3.94-683.15) were found to predict VAI.

CONCLUSION

In patients with acute brain injury and an EVD, our proposed combined cut-off for ruling out VAI performed satisfactorily. Days to sample and CSF WBC/RBC ratio were found independent predictors for VAI in the multivariable logistic regression model.

Global treatment outcomes of extensively drug-resistant tuberculosis in adults: A systematic review and meta-analysis

INTRODUCTION

Historically, extensively drug-resistant tuberculosis has been notoriously difficult to treat with devasting outcomes. As we are coming to the end of an era where the 2006 extensively drug-resistant tuberculosis definitions and old treatment regimens are being replaced, we aimed to estimate the proportion of extensively drug-resistant tuberculosis patients globally who achieved successful treatment outcomes.

METHODS

We conducted a systematic review of PubMed/MEDLINE, Scopus, Web of Science, and Embase from January 1, 2005, through April 3, 2023. Included studies reported WHO treatment outcomes, or adaptions hereof, for pre-extensively and/or extensively drug-resistant tuberculosis patients according to the 2006 WHO definition. Eligible studies included cohorts of at least 10 adults (aged>18 years) that were not pregnant. Using a random-effects model, we calculated pooled proportions of treatment outcomes and performed sensitivity and subgroup analyses. PROSPERO registration number: CRD42022340961.

RESULTS

Among 5056 studies reviewed, we identified 94 studies from 26 countries, involving 10,223 extensively drug-resistant tuberculosis patients. The pooled proportion of successful treatment outcomes was 44.2% (95%CI: 38.3-50.3). Sensitivity analyses consistently produced similar estimates. A slight improvement in treatment outcomes was observed after 2013. Furthermore, 25 studies reported outcomes for 3564 individuals with pre-extensively drug-resistant tuberculosis, of which 63.3% achieved successful treatment (95%CI: 43.1-72.5).

CONCLUSION

Globally, the success rate of extensively drug-resistant tuberculosis treatment is 44.2%, far below the WHO's target rate of 75%. These results may serve as a reference for future studies assessing extensively drug-resistant tuberculosis treatment outcomes under the 2021 definition treated with better treatment regimens available. Comprehensive surveillance data of extensively drug-resistant tuberculosis outcomes from the whole world are desirable to monitor treatment progress.

Mortality, risk factors, and causes of death among people with tuberculosis in Denmark, 1990-2018

OBJECTIVES

This study aimed to analyze mortality, risk factors, and causes of death among people with tuberculosis (TB).

METHODS

This is a population-based cohort study with patients with TB ≥18 years notified from 1990 to 2018 in Denmark, compared with sex- and age-matched controls. Mortality was assessed in Kaplan-Meier models and risk factors for death were estimated in Cox proportional hazards models.

RESULTS

Overall mortality was twofold higher among people with TB compared with controls up to 15 years after TB diagnosis (hazard ratio [HR]: 2.18, 95% confidence interval [CI]: 2.06-2.29, P <0.0001). Danes with TB were three times more likely to die than migrants (adjusted HR: 3.13, 95% CI: 2.84-3.45, P <0.0001). Risk factors for death included living alone, being unemployed, having low income, and comorbidities such as mental illness with substance abuse, lung diseases, hepatitis, and HIV. TB was the most common cause of death (21%), followed by chronic obstructive pulmonary disease (7%), lung cancer (6%), alcoholic liver disease (5%), and mental illness with substance abuse (4%).

CONCLUSION

People with TB had substantially inferior survival up to 15 years after TB diagnosis, in particular, socially disadvantaged Danes with TB with specific comorbidities. This may reflect unmet needs for enhanced treatment of other medical/social conditions during TB treatment.

Reduced vitamin D-induced cathelicidin production and killing of Mycobacterium tuberculosis in macrophages from a patient with a non-functional vitamin D receptor: A case report

Tuberculosis (TB) presents a serious health problem with approximately a quarter of the world’s population infected with Mycobacterium tuberculosis (M. tuberculosis) in an asymptomatic latent state of which 5–10% develops active TB at some point in their lives. The antimicrobial protein cathelicidin has broad antimicrobial activity towards viruses and bacteria including M. tuberculosis. Vitamin D increases the expression of cathelicidin in many cell types including macrophages, and it has been suggested that the vitamin D-mediated antimicrobial activity against M. tuberculosis is dependent on the induction of cathelicidin. However, unraveling the immunoregulatory effects of vitamin D in humans is hampered by the lack of suitable experimental models. We have previously described a family in which members suffer from hereditary vitamin D-resistant rickets (HVDRR). The family carry a mutation in the DNA-binding domain of the vitamin D receptor (VDR). This mutation leads to a non-functional VDR, meaning that vitamin D cannot exert its effect in family members homozygous for the mutation. Studies of HVDRR patients open unique possibilities to gain insight in the immunoregulatory roles of vitamin D in humans. Here we describe the impaired ability of macrophages to produce cathelicidin in a HVDRR patient, who in her adolescence suffered from extrapulmonary TB. The present case is a rare experiment of nature, which illustrates the importance of vitamin D in the pathophysiology of combating M. tuberculosis.

Social determinants of tuberculosis: a nationwide case-control study, Denmark, 1990-2018

BACKGROUND

The global vision is a world free of tuberculosis (TB). Even in resource-rich TB low-incidence settings, we need more focus on the role of social risk factors to end the TB epidemic.

METHODS

Nationwide, retrospective register-based, case-control study from 1990 to 2018, including all TB patients in Denmark ≥18 years old (n = 9581) matched 1:3 on sex and age with population controls. TB risk factors were assessed in logistic regression models and estimated by odds ratio (OR).

RESULTS

All TB patients had considerably lower socio-economic status compared with controls (P < 0.0001). Among ethnic Danes, TB was mostly found among males, persons between 35 and 65 years, those living alone, those with low educational level, persons on social welfare benefits and those with low income. Conversely, for migrants, being younger, sex and living alone were less important, whereas having children was protective. In an adjusted multivariable regression model among Danes, key risk factors for TB were being on disability pension (OR = 2.7) and cash benefits (OR = 4.7). For migrants, fewer social risk factors increased TB risk, although low income and cash benefits did (OR = 3.1).

CONCLUSION

Even today in a resourceful setting, socio-economic status drives disparities in health. In our study, multifactorial social deprivation was highly associated with TB. Especially household structure, education, employment and income were important risk factors that should be addressed in the future to accelerate TB control and end the TB epidemic.

Pregnancy and post-partum tuberculosis; a nationwide register-based case-control study, Denmark, 1990 to 2018

Background

Pregnancy increases the risk of tuberculosis (TB), however, data on TB epidemiology in pregnant women are limited.

Aim

To guide possible interventions, we analysed risk factors for TB in pregnant and post-partum women.

Methods

We conducted a nationwide retrospective register-based case–control study from January 1990 to December 2018 in Denmark. Cases were women diagnosed with TB during their pregnancy or in the post-partum period. We selected two control groups: pregnant or post-partum women without TB, and non-pregnant women with TB. Differences were assessed by chi-squared or Fisher’s exact test. Risk factors for TB were identified through logistic regression and estimated by odds ratio (OR).

Results

We identified 392 cases, including 286 pregnant and 106 post-partum women. Most were migrants (n = 366; 93%) with a shorter median time spent in Denmark (2.74 years; interquartile range (IQR): 1.52–4.64) than non-pregnant TB controls (3.98 years; IQR: 1.43–8.51). Cases less likely had a Charlson comorbidity index ≥ 2compared with non-pregnant TB controls (p < 0.0001), and had no increased risk of severe disease (p = 0.847). Migrants from other World Health Organization regions than Europe, especially Africa (OR: 187; 95%CI: 125–281) had persistently higher odds of TB.

Conclusions

In Denmark, the risk of TB in pregnant and post-partum women is increased in migrant women who have stayed in the country a median time of approximately 3 years. We recommend increased focus on TB risk during pregnancy and suggest evaluating targeted TB screening of selected at-risk pregnant women to promote early case finding and prevent TB among mothers and their newborn children.

The Hammer vs Mitigation-A comparative retrospective register study of the Swedish and Danish national responses to the COVID-19 pandemic in 2020

In the efforts to dampen the COVID‐19 pandemic, governments are compelled to outweigh disease control efforts to the possible negative consequences of closing large parts of society. Although Denmark and Sweden are alike in political organization and health care, national responses to the 2020 COVID‐19 epidemic differed noticeably. Denmark initiated a hard lock down followed by an outbreak control strategy (the so‐called “hammer and dance” strategy), while Sweden’s strategy was based on advising on social distancing, while keeping society open (a so‐called mitigative strategy). The objective of this study is to describe national epidemic control strategies in Denmark and Sweden in 2020, and compare the epidemic dynamics in the two countries, with respect to number of COVID‐19 cases, admissions to intensive care and mortality. Data on epidemic control efforts and COVID‐associated morbidity/mortality were downloaded from official government and epidemic surveillance webpages and comparatively described using basic statistics. Overall, we found “the hammer” resulted in better epidemic control during 2020 with less COVID‐19‐associated admissions to intensive care and lower mortality.

β-cell dysfunction and insulin resistance in relation to pre-diabetes and diabetes among adults in north-western Tanzania: a cross-sectional study

OBJECTIVE

Studies on phenotypes of diabetes in Africa are inconsistent. We assessed the role of β-cell dysfunction and insulin resistance on pre-diabetes and diabetes.

METHODS

We included 1890 participants with mean age of 40.6 (SD11.9) years in a cross-sectional study among male and female adults in Tanzania during 2016 to 2017. Data on C-reactive protein (CRP), alpha-acid glycoprotein (AGP), HIV, oral glucose tolerance test (OGTT), body composition and insulin were collected. Insulinogenic index and HOMA-IR were used to derive an overall marker of β-cell dysfunction and insulin resistance which was categorised as follows: normal β-cell function and insulin sensitivity, isolated β-cell dysfunction, isolated insulin resistance, and combined β-cell dysfunction and insulin resistance. Pre-diabetes and diabetes were defined as 2-hour OGTT glucose between 7.8-11.0 and ≥ 11.1 mmol/L, respectively. Multinomial regression assessed the association of β-cell dysfunction and insulin resistance with outcome measures.

RESULTS

β-cell dysfunction, insulin resistance, and combined β-cell dysfunction and insulin resistance were associated with higher pre-diabetes risk. Similarly, isolated β-cell dysfunction (adjusted relative risk ratio (aRRR) 4.8 (95% confidence interval (CI) 2.5, 9.0), isolated insulin resistance (aRRR 3.2 (95% CI 1.5, 6.9), and combined β-cell dysfunction and insulin resistance (aRRR 35.9 (95% CI 17.2, 75.2) were associated with higher diabetes risk. CRP, AGP and HIV were associated with higher diabetes risk, but fat mass was not. 31%, 10% and 33% of diabetes cases were attributed to β-cell dysfunction, insulin resistance, and combined β-cell dysfunction and insulin resistance, respectively.

CONCLUSIONS

β-cell dysfunction seemed to explain most of diabetes cases compared to insulin resistance in this population. Cohort studies on evolution of diabetes in Africa are needed to confirm these results.

CT and MR neuroimaging findings in patients with Lyme neuroborreliosis: A national prospective cohort study

BACKGROUND

We aimed to describe the use and findings of cranial computerized tomography (CT-head), spine and brain magnetic resonance imaging (MRI-spine/MRI-brain) in Lyme neuroborreliose (LNB).

METHODS

Patients with LNB were identified using a nationwide, population-based prospective cohort of all adults treated for neuroinfections at departments of infectious diseases in Denmark from 2015 to 2019. Multivariate logistic regression analyses assessed associations between clinical characteristics and MRI-findings consistent with LNB.

RESULTS

We included 368 patients (272 definite LNB and 96 probable LNB), 280 scans were performed in 198 patients. Neuroimaging was associated with older age (59 vs. 57, p = 0.03), suspicion of other diseases (77% vs. 37%, p < 0.0001), no history of tick bites (58% vs. 43%, p = 0.01), physical/cognitive deficits prior to admission (15% vs 5%, p = 0.006), peripheral palsy (10% vs. 2%, p = 0.0008), encephalitis (8% vs. 1%, p = 0.0007) and cognitive impairment (8% vs. 2%, p = 0.03) compared with those without neuroimaging. Normal or incidental findings were common (93/98 CT-head and 154/182 MRI). 1/98 CT-head, 19/131 MRI-brain and 6/51 MRI-spine had findings consistent with LNB. Symptoms ≥45 days was associated with MRI-findings consistent with LNB (adjusted odds ratio (aOR) 4.2, 95%confidence interval 1.2-14.4, p = 0.02).

CONCLUSION

In this Danish cohort including 368 LNB-patients, use of neuroimaging was common and often performed in older comorbid patients without previous tick-bite intended to investigate alternative diagnoses. The results were in general without pathology and neuroimaging cannot exclude LNB or replace lumbar puncture. MRI is of value when investigating alternative neurological diseases and may support suspicion of LNB in cases with meningeal/leptomeningeal/neural enhancement.

Mycobacterium arosiense, an unexpected cause of osteomyelitis in a patient with sarcoidosis: a case report

BACKGROUND

Nontuberculous mycobacteria belonging to the Mycobacterium avium complex are recognized as opportunistic pathogens to humans. Mycobacterium arosiense is one of the novel members of the Mycobacterium avium complex. The organism has only rarely been reported in human clinical cases and may be routinely misidentified.

CASE PRESENTATION

An adult male with a history of a discus prolapse and sarcoidosis presented with high fever and a strong back pain with projection to the extremities. A Magnetic Resonance Imaging scan of columna revealed a tumor suspect process at thoracic vertebrae 11/12 with changes at the second lumbar vertebra, which was partly removed by laminectomy. Biopsy smears revealed acid-fast bacilli and turned out to be Mycobacterium tuberculosis complex PCR negative. The routine line probe assay INNO-LiPa v2 (INNOGENETICS NV, Gent), which differentiates 16 mycobacterial species indicated the presence of a not readily identifiable NTM species. Whereas, the GenoType Mycobacterium CM v2.0 (HAIN Lifescience GmbH) that routinely differentiates 14 clinically relevant mycobacteria revealed a Mycobacterium intracellulare species. However, additional diagnostic sequencing of the 16S rRNA gene confirmed the presence of a Mycobacterium arosiense species.

CONCLUSIONS

This is the second unusual case of osteomyelitis with clinical significance ever to be reported, caused by Mycobacterium arosiense and complicated by an underlying sarcoidosis. Mycobacterium arosiense has rarely been reported clinically and the first description of the species was identified as the cause of osteomyelitis in a child with a hereditary partial interferon gamma deficiency. Symptoms attributed to sarcoidosis waned on Mycobacterium arosiense treatment and it is inconclusive whether the patient ever suffered from sarcoidosis. Mycobacterium arosiense was misidentified by the GenoType as Mycobacterium intracellulare and implicates that the diagnosis requires supplemental sequencing of the 16S rRNA gene.

Set-up and validation of mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRU-VNTR) analysis of Mycobacterium tuberculosis using BioNumerics software

The objective was to describe and validate a new and alternative software procedure for 24-locus mycobacterial interspersed repetitive unit-variable number-tandem repeat (MIRU-VNTR) typing of Mycobacterium tuberculosis (Mtb) based on the multipurpose BioNumerics software. DNA from randomly selected isolates of Mtb from two European laboratories, including external control samples for MIRU-VNTR typing, were analysed. Samples were genotyped using the commercial 24-locus VNTR typing kit from GenoScreen. The PCR amplified fragments were separated by capillary electrophoresis. For the subsequent analyses, the currently used software GeneMapper was compared with BioNumerics. The endpoint was the level of concordance when comparing genotyping results obtained from BioNumerics with results obtained from GeneMapper and the ECDC proficiency study reference results. Also, the number of necessary manual standard size corrections and allele assignments in the two different software methods were compared. In total, 272 DNA samples, including the ECDC proficiency panel, were analysed. For all samples, there were 100% concordance of results. For a randomly selected set of 96 samples the numbers of manual corrections needed for size standards were 199 with GeneMapper versus zero for BioNumerics. The numbers of manual corrections for allele assignments were 122 with GeneMapper versus 16 with BioNumerics. In conclusion, we have validated the multipurpose software BioNumerics for standard 24-locus MIRU-VNTR typing and the software shows promising benefits in terms of simplification and minimization of hand-on time.

HIV, TB, inflammation and other correlates of serum phosphate: A cross-sectional study

BACKGROUND

There is little information about serum phosphate levels among patients with pulmonary tuberculosis (TB) and HIV infection.

OBJECTIVE

We aimed to assess the role of TB, HIV, inflammation and other correlates on serum phosphate levels.

METHODS

A cross-sectional study was conducted among TB patients and age- and sex-matched non-TB controls. Pulmonary TB patients were categorized as sputum -negative and -positive, based on culture. Age- and sex-matched non-TB controls were randomly selected among neighbours to sputum-positive TB patients. Data on age, sex, alcohol and smoking habits were obtained. HIV status, serum phosphate, and the acute phase reactants C-reactive protein (serum CRP) and α₁-acid glycoprotein (serum AGP) were determined. Linear regression analysis was used to identify correlates of serum phosphate.

RESULTS

Of 1605 participants, 355 (22.1%) were controls and 1250 (77.9%) TB patients, of which 9.9% and 50.4% were HIV-infected. Serum phosphate was determined before start of TB treatment in 44%, and 1-14 days after start of treatment in 56%. Serum phosphate was up to 0.10 mmol/L higher 1-3 days after start of TB treatment, and lowest 4 days after treatment, after which it increased. In multivariable analysis, TB patients had 0.09 (95% CI: 0.05; 0.13) mmol/L higher serum phosphate than controls, and those with HIV had 0.05 (95% CI: 0.01; 0.08) mmol/L higher levels than those without. Smoking was also a positive correlate of serum phosphate, whereas male sex and age were negative correlates.

CONCLUSION

While HIV and TB are associated with higher serum phosphate, our data suggest that TB treatment is followed by transient reductions in serum phosphate, which may reflect hypophosphataemia in some patients.

Trends and differences in tuberculosis incidences and clustering among natives in Denmark, Sweden and Finland: comparison of native incidences and molecular epidemiology among three low-incidence countries

OBJECTIVES

To compare the epidemiology of tuberculosis (TB) in Denmark, Sweden and Finland, by focusing on the native population in order to identify epidemiologic differences and thus indirectly possible differences in TB control.

METHODS

TB incidence trends from 1990 through 2015 were compared among the countries. In addition, for the periods 2012-2013 and 2014-2015, genotyping data were compared. Genotyping was performed using the 24-locus mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRU-VNTR) method in Denmark and Sweden. For Finland, spoligotyping in conjunction with the 15-locus MIRU-VNTR method was used for 2012-2013 and translated into the 24-locus MIRU-VNTR when feasible, and for 2014-2015 only MIRU-VNTR was used. Both incidence trends and molecular epidemiology were assessed for native cases.

RESULTS

The average annual rate of change in TB incidence for native Danes was -2.4% vs. -6.1% and -6.9% for native Swedes and Finns respectively. In 2012-2013 Denmark had 52 native cases in the largest transmission chain vs. three cases in Sweden and ten in Finland, and during the same period the clustering rate for native Danes was 48.8% vs. 6.5% and 18.2% for native Swedes and Finns respectively. For 2014-2015, a similar pattern was seen.

CONCLUSIONS

The decline of TB among natives in Denmark is slower than for Sweden and Finland, and it seems Denmark has more active transmission among natives. The focused assessment on basic native TB epidemiology reveals striking differences in TB transmission among otherwise similar low-TB-incidence countries.

Prevalence and significance of Mycoplasma genitalium in women living with HIV in Denmark

OBJECTIVE

Mycoplasma genitalium (M. genitalium) is a sexually transmitted pathogen associated with urethritis, cervicitis, and pelvic inflammatory disease. Previous studies have shown a strong association between M. genitalium and HIV infection, therefore screening and treatment for M. genitalium has been suggested as part of HIV prevention strategies. The objective of this study was to determine the prevalence of M. genitalium in women living with HIV (WLWH) in Denmark, and to compare the result with data on symptoms from the lower abdomen, sexual habits and immune status. 234 women, recruited from Danish HIV centres as part of a larger observational study on aspects of living with HIV as a woman (the SHADE study), were included.

RESULTS

We tested cervical samples for M. genitalium by specific PCR. We found three samples positive (1.3%). The women were between 30 and 50 years old, all were of Asian origin, sexually active, and on antiretroviral treatment with supressed HIV RNA and CD4 count >350 cells/µL. None reported symptoms from the lower abdomen. The prevalence of M. genitalium infection in WLWH in Denmark is low, thus systematic screening for M. genitalium in this group does not seem relevant.

Erythema nodosum and the risk of tuberculosis in a high incidence setting

OBJECTIVE

This study estimates the erythema nodosum (EN) incidence in a tuberculosis (TB) endemic setting and evaluates the likelihood of a subsequent TB diagnosis among individuals with Mycobacterium tuberculosis infection (MTI) with or without EN.

DESIGN

We estimated EN incidence rates (IRs) in East Greenland in 2010-2011 and conducted a cohort study following all individuals who tested positive for MTI from 1 January 2010 until 31 December 2012. A personal identifier allowed individual follow-up in the mandatory TB register. MTI was defined by a positive interferon-gamma release assay. TB incidence rate ratios (IRRs) among participants with or without EN were estimated with the Cox proportional hazard model.

RESULTS

We identified 38 EN cases corresponding to an IR of 500/100,000 inhabitants/year. All cases were among individuals with MTI. The EN IR was 11.79 (95% CI 5.73-24.27) times higher for BCG-unvaccinated compared with BCG-vaccinated individuals. The TB IRR was 25 (95% CI 11-60) within 1 month of EN compared to individuals without EN.

CONCLUSION

This study documents a high EN incidence in a TB endemic region. EN occurred only in individuals with MTI, and predominantly among BCG-unvaccinated individuals. EN was significantly associated with a TB diagnosis within 1 month of diagnosis.

Effect of alterations in blood volume with bed rest on glucose tolerance

Bed rest leads to rapid impairments in glucose tolerance. Plasma volume and thus dilution space for glucose are also reduced with bed rest, but the potential influence on glucose tolerance has not been investigated. Accordingly, the aim was to investigate whether bed rest-induced impairments in glucose tolerance are related to a concomitant reduction in plasma volume. This hypothesis was tested mechanistically by restoring plasma volume with albumin infusion after bed rest and parallel determination of glucose tolerance. Fifteen healthy volunteers (age 24 ± 3 yr, body mass index 23 ± 2 kg/m², maximal oxygen uptake 44 ± 8 ml·min^-1·kg^-1; means ± SD) completed 4 days of strict bed rest. Glucose tolerance [oral glucose tolerance test (OGTT)] and plasma and blood volumes (carbon monoxide rebreathing) were assessed before and after 3 days of bed rest. On the fourth day of bed rest, plasma volume was restored by means of an albumin infusion prior to an OGTT. Plasma volume was reduced by 9.9 ± 3.0% on bed rest day 3 and area under the curve for OGTT was augmented by 55 ± 67%. However, no association (R² = 0.09, P = 0.33) between these simultaneously occurring responses was found. While normalization of plasma volume by matched albumin administration (408 ± 104 ml) transiently decreased (P < 0.05) resting plasma glucose concentration (5.0 ± 0.4 to 4.8 ± 0.3 mmol/l), this did not restore glucose tolerance. Bed rest-induced alterations in dilution space may influence resting glucose values but do not affect area under the curve for OGTT.

Tuberculosis screening in patients with HIV: use of audit and feedback to improve quality of care in Ghana

BACKGROUND

Tuberculosis screening of people living with HIV (PLHIV) can contribute to early tuberculosis diagnosis and improved patient outcomes. Evidence-based guidelines for tuberculosis screening are available, but literature assessing their implementation and the quality of clinical practice is scarce.

OBJECTIVES

To assess tuberculosis screening practices and the effectiveness of audit and performance feedback to improve quality of tuberculosis screening at HIV care clinics in Ghana.

DESIGN

Healthcare providers at 10 large HIV care clinics prospectively registered patient consultations during May and October 2014, before and after a performance feedback intervention in August 2014. The outcomes of interest were overall tuberculosis suspicion rate during consultations and provider adherence to the International Standards for Tuberculosis Care and the World Health Organizations' guidelines for symptom-based tuberculosis screening among PLHIV.

RESULTS

Twenty-one healthcare providers registered a total of 2,666 consultations; 1,368 consultations before and 1,298 consultations after the feedback intervention. Tuberculosis suspicion rate during consultation increased from 12.6 to 20.9% after feedback (odds ratio, OR 1.83; 95% confidence interval, CI: 1.09-3.09). Before feedback, sputum smear microscopy was requested for 58.7% of patients with suspected tuberculosis, for 47.2% of patients with cough ≥2 weeks, and for 27.5% of patients with a positive World Health Organization (WHO) symptom screen (any of current cough, fever, weight loss or night sweats). After feedback, patients with a positive WHO symptom screen were more likely to be suspected of tuberculosis (OR 2.21; 95% CI: 1.19-4.09) and referred for microscopy (OR 2.71; 95% CI: 1.25-5.86).

CONCLUSIONS

A simple prospective audit tool identified flaws in clinical practices for tuberculosis screening of PLHIV. There was no systematic identification of people with suspected active tuberculosis. We found low initial tuberculosis suspicion rate compounded by low referral rates of relevant patients for sputum smear microscopy. Adherence to recommended standards and guidelines for tuberculosis screening improved after performance feedback.

Tuberculosis and non-tuberculous mycobacteria among HIV-infected individuals in Ghana

OBJECTIVES

To assess the prevalence and clinical importance of previously unrecognised tuberculosis (TB) and isolation of non-tuberculous mycobacteria (NTM) among HIV-infected individuals in a teaching hospital in Ghana.

METHODS

Intensified mycobacterial case finding was conducted among HIV-positive individuals before initiation of antiretroviral therapy (ART). Data were collected on socio-demographic characteristics, medical history and TB-related signs and symptoms, and participants were followed for six months to determine treatment and vital status. Two sputum samples were obtained and examined for mycobacteria with smear microscopy, culture and Xpert MTB/RIF assay. NTM species were identified with the GenoType Mycobacterium CM/AS or sequence analysis of 16S rRNA gene.

RESULTS

Of 473 participants, 60 (12.7%) had confirmed pulmonary TB, and 38 (8.0%) had positive cultures for NTM. Mycobacterium avium complex was identified in 9/38 (23.7%) of NTM isolates. Participants with NTM isolated were more likely to have CD4 cell count< 100 cells/μL (aOR 2.37; 95% CI: 1.10-5.14), BMI<18.5kg/m(2) (aOR 2.51; 95% CI: 1.15-5.51) and fever ≥2 weeks (aOR 2.76; 95% CI: 1.27-6.03) at baseline than participants with no mycobacteria. By six months, 76 (16.1%) participants had died; 20 (33.3%) with confirmed TB and 9 (23.7%) with NTM-positive culture. Mortality at six months was independently associated with TB diagnosis at enrolment (aHR 1.97; 95% CI 1.09-3.59), but not with NTM isolation after controlling for age, sex, CD4 cell count, BMI, prolonged fever and ART initiation.

CONCLUSIONS

Intensified mycobacterial screening of HIV-infected individuals revealed a high burden of unrecognised pulmonary TB before ART initiation, which increased risk of death within six months. NTM were frequently isolated and associated with signs of poor clinical status but not with increased mortality.

Occupational Tuberculosis in Denmark through 21 Years Analysed by Nationwide Genotyping

Tuberculosis (TB) is a well-known occupational hazard. Based on more than two decades (1992–2012) of centralized nationwide genotyping of all Mycobacterium tuberculosis culture-positive TB patients in Denmark, we compared M. tuberculosis genotypes from all cases notified as presumed occupational (N = 130) with M. tuberculosis genotypes from all TB cases present in the country (N = 7,127). From 1992 through 2006, the IS6110 Restriction Fragment Length Polymorphism (RFLP) method was used for genotyping, whereas from 2005 to present, the 24-locus-based Mycobacterial Interspersed Repetitive Unit-Variable Number of Tandem Repeat (MIRU-VNTR) was used. An occupational TB case was classified as clustered if the genotype was 100% identical to at least one other genotype. Subsequently, based on genotype, time period, smear positivity, geography, susceptibility pattern, and any reported epidemiological links between the occupational cases and any potential source cases, the occupational case was categorized as confirmed, likely, possible or unlikely occupationally infected. Among the 130 notified presumed occupational cases, 12 (9.2%) could be classified as confirmed and 46 (35.4%) as unlikely, accounting for nearly half of all cases (44.6%). The remaining 72 cases (55.4%) were categorized as possible. Within this group, 15 cases (11.5%) were assessed to be likely occupational. Our study shows that genotyping can serve as an important tool for disentangle occupational TB in high-income low incidence settings, but still needs to be combined with good epidemiological linkage information.

Pharmacokinetics of Isoniazid, Pyrazinamide, and Ethambutol in Newly Diagnosed Pulmonary TB Patients in Tanzania

Exposure to lower-than-therapeutic levels of anti-tuberculosis drugs is likely to cause selection of resistant strains of Mycobacterium tuberculosis and treatment failure. The first-line anti-tuberculosis (TB) regimen consists of rifampicin, isoniazid, pyrazinamide, and ethambutol, and correct management reduces risk of TB relapse and development of drug resistance. In this study we aimed to investigate the effect of standard of care plus nutritional supplementation versus standard care on the pharmacokinetics of isoniazid, pyrazinamide and ethambutol among sputum smear positive TB patients with and without HIV. In a clinical trial in 100 Tanzanian TB patients, with or without HIV infection, drug concentrations were determined at 1 week and 2 months post initiation of anti-TB medication. Data was analysed using population pharmacokinetic modelling. The effect of body size was described using allometric scaling, and the effects of nutritional supplementation, HIV, age, sex, CD4+ count, weight-adjusted dose, NAT2 genotype, and time on TB treatment were investigated. The kinetics of all drugs was well characterised using first-order elimination and transit compartment absorption, with isoniazid and ethambutol described by two-compartment disposition models, and pyrazinamide by a one-compartment model. Patients with a slow NAT2 genotype had higher isoniazid exposure and a lower estimate of oral clearance (15.5 L/h) than rapid/intermediate NAT2 genotype (26.1 L/h). Pyrazinamide clearance had an estimated typical value of 3.32 L/h, and it was found to increase with time on treatment, with a 16.3% increase after the first 2 months of anti-TB treatment. The typical clearance of ethambutol was estimated to be 40.7 L/h, and was found to decrease with age, at a rate of 1.41% per year. Neither HIV status nor nutritional supplementations were found to affect the pharmacokinetics of these drugs in our cohort of patients.

Diagnostic accuracy of the rapid urine lipoarabinomannan test for pulmonary tuberculosis among HIV-infected adults in Ghana-findings from the DETECT HIV-TB study

Background

Rapid diagnostic tests are urgently needed to mitigate HIV-associated tuberculosis (TB) mortality. We evaluated diagnostic accuracy of the rapid urine lipoarabinomannan (LAM) test for pulmonary TB and assessed the effect of a two-sample strategy.

Methods

HIV-infected adults eligible for antiretroviral therapy were prospectively enrolled from Korle-Bu Teaching Hospital in Ghana and followed for minimum 6 months. We applied the LAM test on urine collected as a spot and early morning sample. Diagnostic accuracy was analysed for a microbiological TB reference standard based on sputum culture and Gene Xpert MTB/RIF results and for a composite reference standard including clinical follow-up data. Performance of sputum smear microscopy was included for comparison.

Results

Of 469 patients investigated for TB, the LAM test correctly identified 24/55 (44 %) of microbiologically confirmed TB cases. Sensitivity of the LAM test was positively associated with hospitalisation (67 %), Modified Early Warning Score > 4 (57 %) and subsequent death (71 %). LAM test specificity was 95 % increasing to 98 % for the composite reference standard. A two-sample LAM test strategy did not improve test performance. Using concentrated sputum for Ziehl-Neelsen and fluorescence microscopy in combination yielded a sensitivity of 31/55 (56 %) that increased to 35/55 (64 %) when the LAM test was added. Surprisingly, nontuberculous mycobacteria were cultured in 34/469 (7 %) and associated with a positive LAM test (p = 0.008).

Conclusions

LAM test sensitivity was highest in patients with poor prognosis and subsequent death and did not increase with a two-sample strategy. A rigorous sputum microscopy strategy had superior sensitivity, but the simplicity of the LAM test holds operational possibilities as a TB screening method among severely sick patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1151-1) contains supplementary material, which is available to authorized users.

Lipid-based nutrient supplements do not affect efavirenz but lower plasma nevirapine concentrations in Ethiopian adult HIV patients

OBJECTIVES

Lipid-based nutrient supplements (LNSs) are increasingly used in HIV programmes in resource-limited settings. However, the possible effects of LNSs on the plasma concentrations of antiretroviral drugs have not been assessed. Here, we aimed to assess the effects of LNSs on plasma efavirenz and nevirapine trough concentrations in Ethiopian adult HIV-infected patients.

METHODS

The effects of LNSs were studied in adults initiating antiretroviral therapy (ART) in a randomized trial. Patients with body mass index (BMI) > 17 kg/m(2) (n = 282) received daily supplementation of an LNS containing whey (LNS/w), an LNS containing soy (LNS/s) or no LNS. Trough plasma concentrations of efavirenz and nevirapine were measured at 1 and 2 months. Genotyping for 516 G>T and 983 T>C polymorphisms of the cytochrome P450 (CYP) 2B6 locus was performed. Multilevel linear mixed-effects models were used to assess the associations between LNS and plasma efavirenz and nevirapine concentrations.

RESULTS

In patients with BMI > 17 kg/m(2), nevirapine concentrations were lower in the LNS/w and LNS/s groups by a median of -2.3 μg/mL [interquartile range (IQR) -3.9; -0.9 μg/mL; P = 0.002] and -2.1 μg/mL (IQR -3.9; -0.9 μg/mL; P = 0.01), respectively, compared with the group not receiving supplements. There were no differences between groups with respect to efavirenz plasma concentrations. The CYP2B6 516 G>T polymorphism was associated with a 5 μg/mL higher plasma efavirenz concentration compared with the wild type (P < 0.0001), while it was not associated with plasma nevirapine concentrations.

CONCLUSIONS

Intake of an LNS was associated with lower plasma nevirapine trough concentrations, indicating possible drug-LNS interactions. The clinical relevance of such reductions in nevirapine exposure is not clear. Plasma efavirenz concentration was not affected by the LNS.

Predictors of body composition changes during tuberculosis treatment in Mwanza, Tanzania

BACKGROUND/OBJECTIVES

Gains in fat mass and lean mass during tuberculosis (TB) treatment may determine functional recovery and survival; yet, data are scarce. We aimed to assess predictors of fat and fat-free mass during 2 months of intensive TB treatment in a cohort in Mwanza, Tanzania.

SUBJECTS/METHODS

Fat and fat-free mass were determined at the start of TB treatment and repeated after 2 months using the deuterium dilution technique. Gains in fat and fat-free mass were determined and predictors assessed using regression analysis.

RESULTS

Data for 116 patients were available at baseline and during follow-up. Of these, 38.8% were females, mean age was 37.3 (s.d. 13.5) years, 69% (81) had sputum-positive TB, 45.7% (53) were HIV infected and 25% (29) were current smokers. The mean weight gain was 3.3 kg (95% confidence interval: 2.7; 3.8), and it did not differ by sex. However, compared with females, males had 1.0 (0.4; 1.6) kg/m(2) lower fat mass but 0.7 (0.2; 1.3) kg/m(2) higher fat-free mass gain. Current smoking was associated with higher fat mass (0.7 kg/m(2), 0.04; 1.4) but lower fat-free mass (-0.5 kg/m(2), -1.2; 0.07) gain. Among HIV-infected patients, antiretroviral therapy (ART) led to a lower fat gain (-1.2 kg/m(2), -2.2; -0.2) but to a higher fat-free mass among sputum-negative (2.9 kg/m(2), 0.8; 5.1) but not sputum-positive patients.

CONCLUSIONS

During intensive phase of TB treatment, sex, smoking and ART were predictors of body composition. Larger studies are needed to further understand predictors of body composition during recovery, to help design interventions to improve treatment outcomes.

The role of anthropometric and other predictors for diabetes among urban Tanzanians with tuberculosis

BACKGROUND

As diabetes impairs tuberculosis (TB) treatment outcomes, it is essential to identify diabetes among TB patients. While little is known about predictors of diabetes among healthy individuals in Africa, predictors among TB patients are almost non-existent.

OBJECTIVE

To assess potential predictors for diabetes among newly diagnosed pulmonary TB patients in Tanzania.

METHODS

TB patients were tested for diabetes using an oral glucose tolerance test, demographic information was collected and anthropometric measurements taken. The association between diabetes and possible predictors were examined using logistic regression analyses.

RESULTS

Of 1205 TB patients, 16.4% (n = 197) had diabetes, 9.0% (n = 108) were aged ≥55 years, 3.3% (n = 40) were overweight (body mass index [BMI] ≥ 25 kg/m(2)) and 12.7% (n = 152) severely underweight (BMI < 16 kg/m(2)). Diabetes was most prevalent in the 45-55 year age group, and increasing weight, BMI and waist circumference were associated with diabetes. Severe underweight (BMI < 16 kg/m(2)) among male TB patients (sex-BMI interaction, P = 0.02) was associated with diabetes (OR 2.52, P = 0.004).

CONCLUSION

Diabetes is a common comorbidity among TB patients. Although diabetes was associated with obesity and was more prevalent among the middle-aged, the majority of TB patients with diabetes comorbidity were young and lean. With diabetes as a major risk factor for TB, and with the lack of strong predictors for diabetes, universal diabetes screening should be implemented in the TB programme.

Migrant tuberculosis: the extent of transmission in a low burden country

Background

Human migration caused by political unrest, wars and poverty is a major topic in international health. Infectious diseases like tuberculosis follow their host, with potential impact on both the migrants and the population in the recipient countries. In this study, we evaluate Mycobacterium tuberculosis transmission between the national population and migrants in Denmark.

Methods

Register study based on IS6110-RFLP results from nationwide genotyping of tuberculosis cases during 1992 through 2004. Cases with 100% identical genotypes were defined as clustered and part of a transmission chain. Origin of clusters involving both Danes and migrants was defined as Danish/migrant/uncertain. Subsequently, the proportion of cases likely infected by the "opposite" ethnic group was estimated.

Results

4,631 cases were included, representing 99% of culture confirmed cases during 1992 through 2004. Migrants contributed 61.6% of cases. Up to 7.9% (95% CI 7.0-8.9) of migrants were infected by Danes. The corresponding figure was 5.8% (95% CI 4.8-7.0) for Danes. Thus, transmission from Danes to migrants occurred up to 2.5 (95% CI 1.8-3.5) times more frequent than vice versa (OR = 1). A dominant strain, Cluster-2, was almost exclusively found in Danes, particular younger-middle-aged males.

Conclusions

Transmission between Danes and migrants is limited, and risk of being infected by the "opposite" ethnic group is highest for migrants. TB-control efforts should focus on continues micro-epidemics, e.g. with Cluster-2 in Danes, prevention of reactivation TB in high-risk migrants, and outbreaks in socially marginalized migrants, such as Somalis and Greenlanders. Fears that TB in migrants poses a threat for resident Danes seem exaggerated and unjustified. We believe this to be true for other low incidence countries as well.

Combined IL-12 receptor and IgA deficiency in an adult man intestinally infested by an unknown, non-cultivable mycobacterium

Interleukin-12 receptor deficiency is a well-described cause of human susceptibility to infection with low-virulent mycobacteria and Salmonella species. We identified a male patient presenting in his late forties with severe gastroenteropathy because of outbred infestation by a previously unknown mycobacterium. In addition to selective IgA deficiency, the patient was found to carry a not previously described R283X homozygous mutation in his IL12RΒ1 gene. Two of his sisters, a brother, and his four children were healthy, heterozygous carriers of the mutation. In this patient, the combination of two deficiencies could promote illness. Even though the IgA deficiency in itself does not predispose to mycobacterial disease, the lack of secreted IgA may have disturbed the intestinal homoeostasis and increased the susceptibility to the low-virulent mycobacterium that the patient was not able to clear because of his IL12R deficiency. Antimycobacterial chemotherapy and interferon-γ treatment for 2 years significantly improved his condition. This is the first description of IL12RΒ1 deficiency combined with another immunodeficiency, and we suggest that combinatory defects may circumvent the otherwise low penetrance of IL12RB1 deficiency.

Diabetes is a risk factor for pulmonary tuberculosis: a case-control study from Mwanza, Tanzania

BACKGROUND

Diabetes and TB are associated, and diabetes is increasingly common in low-income countries where tuberculosis (TB) is highly endemic. However, the role of diabetes for TB has not been assessed in populations where HIV is prevalent.

METHODS

A case-control study was conducted in an urban population in Tanzania among culture-confirmed pulmonary TB patients and non-TB neighbourhood controls. Participants were tested for diabetes according to WHO guidelines and serum concentrations of acute phase reactants were measured. The association between diabetes and TB, and the role of HIV as an effect modifier, were examined using logistic regression. Since blood glucose levels increase during the acute phase response, we adjusted for elevated serum acute phase reactants.

RESULTS

Among 803 cases and 350 controls the mean (SD) age was 34.8 (11.9) and 33.8 (12.0) years, and the prevalence of diabetes was 16.7% (95% CI: 14.2; 19.4) and 9.4% (6.6; 13.0), respectively. Diabetes was associated with TB (OR 2.2, 95% CI: 1.5; 3.4, p<0.001). However, the association depended on HIV status (interaction, p = 0.01) due to a stronger association among HIV uninfected (OR 4.2, 95% CI: 1.5; 11.6, p = 0.01) compared to HIV infected (OR 0.1, 95% CI: 0.01; 1.8, p = 0.13) after adjusting for age, sex, demographic factors and elevated serum acute phase reactants.

CONCLUSION

Diabetes is a risk factor for TB in HIV uninfected, whereas the association in HIV infected patients needs further study. The increasing diabetes prevalence may be a threat to TB control.

Risk factors for Mycobacterium tuberculosis infection among children in Greenland

OBJECTIVE

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

METHODS

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

FINDINGS

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

CONCLUSION

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

Daily multi-micronutrient supplementation during tuberculosis treatment increases weight and grip strength among HIV-uninfected but not HIV-infected patients in Mwanza, Tanzania

Undernutrition is common among tuberculosis (TB) patients. The objective of this study was to assess the effect of multi-micronutrient supplementation during TB treatment on weight, body composition, and handgrip strength. A total of 865 patients with smear-positive (PTB+) or -negative (PTB-) pulmonary TB were randomly allocated to receive a daily biscuit with or without multi-micronutrients for 60 d during the intensive phase of TB treatment. Weight, arm fat area, arm muscle area, and handgrip strength were assessed at baseline and after 2 and 5 mo. At 2 mo, the multi-micronutrient supplementation led to a higher handgrip gain (1.22 kg; 95% CI = 0.50, 1.94; P = 0.001) but had no effects on other outcomes. The effects of multi-micronutrient supplementation were modified by HIV infection (P-interaction = 0.002). Among HIV- patients, multi-micronutrient supplementation increased weight gain by 590 g (95% CI = -40, 1210; P = 0.07) and handgrip strength by 1.6 kg (95% CI = 0.78, 2.47; P < 0.001), whereas among HIV+ patients, it reduced weight gain by 1440 g (95% CI = 290, 2590; P = 0.002) and had no effect on handgrip strength (0.07 kg; 95% CI = -1.30, 1.46; P = 0.91). The reduced weight gain among HIV+ patients receiving multi-micronutrient supplementation seemed to be explained by a higher proportion of patients reporting fever. At 5 mo, the effects on weight were sustained, whereas there was no effect on handgrip strength. In conclusion, multi-micronutrient supplementation given as a biscuit is beneficial among HIV- PTB patients and may be recommended to TB programs. More research is needed to develop an effective supplement for HIV+ PTB patients.

Weight, body composition and handgrip strength among pulmonary tuberculosis patients: a matched cross-sectional study in Mwanza, Tanzania

This study aimed to estimate deficits in weight, arm fat area (AFA), arm muscle area (AMA) and handgrip strength among smear-positive pulmonary TB (PTB+) patients starting treatment. We conducted a cross-sectional study among PTB+ patients and age- and sex-matched neighborhood controls. HIV status, anthropometric measurements and handgrip strength were determined. Deficits in weight, AFA, AMA and handgrip strength associated with PTB+ and HIV were estimated using multiple regression analysis. We recruited 355 pairs of PTB+ patients and controls. PTB+ was associated with deficits of 10.0kg (95% CI 7.3; 12.7) in weight and 6.8kg (95% CI 5.2; 8.3) in handgrip strength among females and 9.1kg (95% CI 7.3; 10.9) in weight and 6.8kg (95% CI 5.2; 8.4) in handgrip strength among males. In both sexes, PTB+ was associated with deficits in AFA and AMA. Among females, HIV was associated with deficits in AMA and handgrip strength, but the deficit in handgrip strength was larger among PTB+ patients (3.2kg 95% CI 1.3; 5.2) than controls (-1.6kg 95% CI -4.8; 1.5) (interaction, P=0.009). These findings suggest that deficits in weight and handgrip strength among patients starting TB treatment are severe. Thus, nutritional support may be necessary to ensure reversal of the deficits, and may improve treatment outcomes.

Body composition of HIV-positive patients with pulmonary tuberculosis: a cross-sectional study in Mwanza, Tanzania

To estimate the weight deficit and body composition of cases of pulmonary TB (PTB), and assess the roles of HIV and the acute-phase response, a cross-sectional study was carried out in Tanzania. Weight, body mass index (BMI), arm muscle area (AMA), arm fat area (AFA) and the serum concentration of the acute-phase protein alpha(1)-antichymotrypsin (serum ACT) were evaluated for each of 532 cases of PTB and 150 'non-TB' controls. On average, the female cases of PTB not only weighed 7.8 kg less but also had BMI that were 3.1-kg/m(2) lower, AMA that were 14.8-cm(2) lower, and AFA that were 7.6-cm(2) lower than those seen in the female subjects without TB. Similarly, on average, the male cases of PTB weighed 7.1 kg less and had BMI that were 2.5-kg/m(2) lower, AMA that were 18.8-cm(2) lower and AFA that were 1.6-cm(2) lower than those seen in the male subjects without TB. Although HIV infection was associated with a 1.7-kg lower weight and a 0.6-kg/m(2) lower BMI (with deficits in both AMA and AFA) among males, it was not associated with any such deficits among the female subjects. Elevated serum ACT was found to be a negative predictor of BMI, AMA and AFA, partially explaining the effects of the PTB but not those of the HIV. There is need for a better understanding of the determinants and effects of loss of fat and lean body mass in HIV-positive tuberculosis.

Recurrent tuberculosis in Denmark: relapse vs. re-infection

SETTING

Denmark, a country with a low-incidence of tuberculosis (TB).

OBJECTIVE

To analyse the proportion of relapse vs. re-infection and to compare selected characteristics between the two subgroups.

DESIGN

A population-based cohort study. All 4154 Mycobacterium tuberculosis isolates from patients in Denmark genotyped by insertion sequence 6110 restriction fragment length polymorphism were followed for recurrent TB over 13.5 years. Recurrent cases were classified as relapse or re-infection by genotype patterns in initial and serial disease episodes.

RESULTS

Recurrent TB was found in 73 (1.8%) cases. Identical M. tuberculosis genotypes in initial and serial episodes were found in 54 (1.3%), indicating relapse, whereas different genotypes, representing re-infection, were found in 19 (0.5%) cases. Cavitary TB in the initial episode was significantly associated with relapse (OR 4.6, 95%CI 1.1-26.9) compared to re-infection.

CONCLUSION

The rate of recurrent TB is low in Denmark. Comparing selected characteristics between the relapse and re-infection subgroups revealed that only the presence of cavitary disease was associated with relapse. Although recurrent TB was rarely due to re-infection, the risk of re-infection increased with time.

Mycobacterium arosiense sp. nov., a slowly growing, scotochromogenic species causing osteomyelitis in an immunocompromised child

A yellow-pigmented, scotochromogenic, slowly growing mycobacterial strain, designated T1921(T), was isolated from the disseminated osteomyelitic lesions of a 7-year-old child with an underlying partial gamma interferon receptor alpha-1 deficiency. Hybridization by the line probe assay indicated the presence of a Mycobacterium species. Sequencing of the 16S rRNA gene, the internally transcribed spacer (ITS) region and the hsp65 and rpoB genes revealed that strain T1921(T) could be differentiated from all recognized species of the genus Mycobacterium. Phylogenetic analysis based on the 16S rRNA gene indicated that strain T1921(T) was related most closely to Mycobacterium intracellulare, whereas analysis based on the ITS and hsp65 and rpoB genes indicated that it was most closely related to Mycobacterium avium. Phenotypic tests were not able to differentiate strain T1921(T) from similar slowly growing mycobacteria. Strain T1921(T) is considered to represent a novel species of the genus Mycobacterium, for which the name Mycobacterium arosiense sp. nov. is proposed. The type strain is T1921(T) (=DSM 45069(T) =ATCC BAA-1401(T)).

HIV and parasitic co-infections in tuberculosis patients: a cross-sectional study in Mwanza, Tanzania

A cross-sectional study was conducted in Mwanza, Tanzania, to determine the burden of HIV and parasitic co-infections among patients who were confirmed or suspected cases of pulmonary tuberculosis (PTB). Of the 655 patients investigated, 532 (81.2%) had been confirmed as PTB cases, by microscopy and/or culture (PTB+), whereas the other 123 (18.8%) were only suspected cases, on the basis of other clinical criteria (PTB-). Hookworm and Schistosoma mansoni infections were common in the patients, with prevalences of 18% and 34%, respectively. Malarial, Ascaris lumbricoides, Trichuris trichiura and Strongyloides stercoralis infections were less common, each recorded at a prevalence of <5%. The PTB+ patients were less likely to be HIV-positive than the PTB- patients (43.6% v. 62.6%; P<0.0001). Among the PTB+ patients, the HIV-positive had a significantly lower prevalence (12.1% v. 25%; P<0.0001) and mean intensity (49 v. 123 eggs/g; P=0.003) of hookworm infection than the HIV-negative. The PTB patients in the study area were, however, still frequently co-infected with HIV and with parasitic infections that may increase morbidity and accelerate the progression of HIV disease.

Elevated levels of soluble urokinase receptor in serum from mycobacteria infected patients: still looking for a marker of treatment efficacy

In search for a serological marker, which may be used to monitor treatment efficacy in patients with extra-pulmonary mycobacterial infections, serum samples were collected prospectively from patients during a 6-months treatment period. The levels of soluble urokinase-type plasminogen activator receptor (suPAR) and soluble tumour necrosis factor receptor II (sTNFrII) were measured and compared with erythrocyte sedimentation rate (SR) and C-reactive protein levels (CRP). sTNFrII levels were elevated at the time of diagnosis and declined in parallel with traditional inflammation markers (SR and CRP). suPAR levels were elevated to more than double (median 7.7 ng/ml, range 5.6-25.8) compared to levels previously reported for patients with pulmonary tuberculosis. The serum suPAR levels however remained high during the entire treatment period. This may reflect that significant inflammatory activity is continuing for more than 6 months in patients with extrapulmonary mycobacterial infections, despite adequate anti-tuberculosis treatment.

Influence of candidate susceptibility genes on tuberculosis in a high endemic region

Genetic susceptibility towards clinical tuberculosis has been proposed in several population studies. We investigated whether polymorphisms in the candidate genes encoding solute carrier 11a1 protein (SLC11A1 formerly NRAMP1), mannose-binding lectin (MBL2) and Vitamin D receptor (VDR) were associated with tuberculosis in an East-African setting. Four hundred and forty-three culture positive pulmonary tuberculosis patients and 426 controls from Mwanza district in the northern part of Tanzania were prospectively included. Polymorphisms in the candidate genes were detected by different PCR-based techniques. A significant association between pulmonary tuberculosis and a microsatellite marker in the 5'(CA)n locus in the SLC11A1 gene compared with controls (38% versus 30% odds ratio 1.45, 95% CI: 1.06-1.9, P=0.014) was observed. The association was apparent only in HIV negative tuberculosis patients. No association with tuberculosis was seen with 3 other SLC11A1 loci investigated, which previously have been associated with tuberculosis in other populations or with MBL2 and VDR polymorphisms. The tuberculosis associated microsatellite marker was situated on different SLC11A1 haplotypes. In this cohort a microsatellite marker in the 5'(CA)n locus situated in the SLC11A1 gene was associated with tuberculosis. The observed association was seen only in HIV negative patients suggesting that this genetic susceptibility for tuberculosis may be surpassed by co-infections.

The long-term pharmacokinetics and safety of adding low-dose ritonavir to a nelfinavir 1250 mg twice-daily regimen in HIV-infected patients

OBJECTIVES

To evaluate the long-term pharmacokinetics and safety of adding ritonavir 100 mg twice-daily to a nelfinavir 1250 mg twice-daily regimen in HIV-infected patients.

METHODS

This was a prospective, randomized, open-label, controlled 24-week study. Sixteen patients receiving a nelfinavir 1250 mg twice-daily regimen with plasma viral load <1000 HIV-1 RNA copies/mL were randomized to continue treatment or to have ritonavir 100 mg twice-daily added. Safety, including fasting lipid levels, was evaluated at weeks 4, 12 and 24. Patients who were randomized to have ritonavir added (n=9) participated in three 12-h pharmacokinetic evaluations at baseline, week 4 and week 24.

RESULTS

Increases in median nelfinavir steady-state plasma concentrations at 12 h (C(12)) from 512 to 773 ng/mL [median difference 450 ng/mL; 95% confidence interval (CI) 116--1510 ng/mL] and in median active nelfinavir metabolite M 8 C(12) from 107 to 603 ng/mL (median difference 545 ng/mL; 95% CI 370--891) were seen after the addition of low-dose ritonavir (baseline to week 24). There were no differences between the nelfinavir or M 8 pharmacokinetic parameters at weeks 4 and 24. No significant changes or differences in the concentration of fasting total cholesterol, low-density lipoprotein (LDL) cholesterol or total triglycerides or in the occurrence of adverse events were observed within or between the two groups.

CONCLUSIONS

Nelfinavir and especially M 8 concentrations are increased when low-dose ritonavir is added to a nelfinavir-containing regimen. The combination seems to be safe and the nelfinavir/ritonavir regimen could be an option in patients with low nelfinavir+M 8 concentrations.

A dominant Mycobacterium tuberculosis strain emerging in Denmark

SETTING

Denmark, a high-income country with a low prevalence of tuberculosis.

OBJECTIVE AND DESIGN

Molecular epidemiological studies of Mycobacterium tuberculosis strains are conducted worldwide, and distinct strains have been associated with large outbreaks of tuberculosis. This is the first systematic population-based search for distinct strains of M. tuberculosis in Denmark among 4102 strains DNA fingerprinted nationwide from 1992 to 2001.

RESULTS

A specific strain of M. tuberculosis has emerged rapidly in Denmark: in 1992, the Danish Cluster 2 strain accounted for 5.8% of all culture-positive Danish-born cases, increasing to 29.0% in 2001. The Cluster 2 cases were on average younger (41.8 vs. 51.4 years), more likely to be male (81.4% vs. 64.1%), and more likely to have pulmonary involvement only (90.3% vs. 64.6%) than other Danish-born cases. During the first 4 observation years, they were mainly found in the capital city, Copenhagen, but were later increasingly observed in the provinces.

CONCLUSION

The reasons for the increasing dominance and change in geographical distribution of Cluster 2 strains in Denmark is unknown, but may be partly explained by the fact that Cluster 2 is associated with younger males with pulmonary disease manifestation. We consider it as an outbreak and believe the situation requires increased focus on early tuberculosis diagnosis and control of transmission in Denmark.

Pharmacokinetic Interaction between Rifampin and the Combination of Indinavir and Low‐Dose Ritonavir in HIV‐Infected Patients

Rifampin is an important drug in the treatment of tuberculosis, but administration of rifampin in combination with protease inhibitors is complicated because of drug-drug interactions. A prospective, controlled, multiple-dose study involving 6 HIV-infected patients receiving a combination of indinavir (800 mg) and ritonavir (100 mg) twice a day was performed to evaluate whether the inducing effect of rifampin on the drug-metabolizing enzyme cytochrome P450 (CYP) 3A4 could be overcome by the inhibitory effect of ritonavir. Pharmacokinetic evaluations of steady-state concentrations of indinavir and ritonavir were performed before and after administration of rifampin (300 mg every day for 4 days). An 87% reduction (from 837 to 112 ng/mL) in median indinavir and a 94% reduction (from 431 to 27 ng/mL) in median ritonavir concentrations were seen 12 h after the last dose of rifampin was administered (P=.031). These results strongly indicate that the administration of rifampin with a combination of indinavir (800 mg) and ritonavir (100 mg) could lead to subtherapeutic concentrations of indinavir.

A prospective evaluation of the clinical value of nation-wide DNA fingerprinting of tuberculosis isolates in Denmark

SETTING

Denmark, a country with a low incidence of tuberculosis (TB).

OBJECTIVE

To evaluate the value of the nation-wide DNA fingerprinting of Mycobacterium tuberculosis isolates performed in Denmark since 1992.

DESIGN

Prospective study of consecutive patients with culture-verified TB from five large TB Departments in Denmark during a 7-month period in 1998. Results of IS6110 RFLP and spoligotyping were compared to those in the nation-wide Danish DNA-fingerprint database which covers approximately 95% of all culture-verified TB cases from 1992 onwards. Questionnaires asking about contact tracing and epidemiological links were sent to the patients' treating physicians.

RESULTS

Of the 177 patients included in the study, 57 were Danes, one was from Iceland, 111 were immigrants, and eight were from Greenland. Responses to the questionnaires were obtained from 163 patients (92%). Four cases of unsuspected transmission were detected: one of nosocomial spread of TB, one of occupational acquisition of TB and two of transmission in an international school, leading to further contact tracing among 75 schoolchildren. These four cases were all the result of short-term contacts. In 22 cases, contact with one or more TB patient(s) was reported. In six of these, the DNA-fingerprint result revealed that the presumed contact could not be the source of infection, even though in two of the cases the known TB contact was from the household.

CONCLUSION

Nation-wide DNA fingerprinting of TB isolates provides information that could not have been obtained otherwise, and contribute to the understanding of TB transmission in Danish society. In some cases the results lead to further contact tracing. Short-term contact can apparently result in transmission of TB.

Usefulness of spoligotyping To discriminate IS6110 low-copy-number Mycobacterium tuberculosis complex strains cultured in Denmark

Mycobacterium tuberculosis complex strains cultured in Denmark have been analyzed by IS6110 restriction fragment length polymorphism (RFLP) on a routine basis from 1992 and onwards. Due to the influx of immigrants with tuberculosis, the number of strains harboring only one to five copies of IS6110 has increased steadily. Since the discriminatory power of IS6110 fingerprinting for such strains is poor, we have performed additional genotyping of all low-copy-number strains by the recently described PCR-based method known as spoligotyping. A total of 311 clinical strains were typed: 14 Mycobacterium bovis BCG, 48 M. bovis, and 249 M. tuberculosis strains. Spoligotyping correctly differentiated M. bovis and M. bovis BCG from M. tuberculosis strains, but it did not differentiate M. bovis from M. bovis BCG. All M. bovis BCG strains exhibited identical spoligotype patterns. The discriminatory power of spoligotyping of low-copy-number M. tuberculosis strains was higher than that of IS6110 fingerprinting. Based on RFLP typing solely, 83% of the low-copy-number M. tuberculosis strains were found to form part of a cluster, and 75% were found to form a cluster on the basis of spoligotyping. When the two techniques were combined, the amount of clustering decreased to 55%. The combination of these two techniques might be valuable in studying the epidemiology of M. tuberculosis strains harboring few copies of the IS6110 element.

Epidemiology of tuberculosis in HIV-infected patients in Denmark

Denmark is an area of low incidence of HIV and tuberculosis (TB). The number of newly reported cases of HIV has been stable during the 1990s, whereas the number of TB cases has doubled in Denmark in the past decade, mainly due to immigration. However, among native Danes the incidence of TB has increased in the younger age groups, indicating more newly infected persons. This study was performed in order to assess the impact of the HIV epidemic and immigration on TB incidence among native Danes. The study was also designed to reveal transmission patterns of TB among HIV-positive patients. Data from HIV-TB co-infected patients identified in the national registers of TB and AIDS from 1992-95 were collected retrospectively from medical records. Restriction fragment length polymorphism (RFLP) analyses of TB isolates from co-infected patients were compared with all patterns registered in the nationwide Danish RFLP database (approximately 1,700 patients). Sixty-seven co-infected patients were identified, 26 Danes and 41 immigrants, representing only 4% of all TB cases during the study period. Danish co-infected patients were part of a cluster, i.e. they had a RFLP-pattern identical to a pattern in the national RFLP database, more often than immigrants (83% vs. 45%, p < 0.005). In only 2 cases were co-infected Danes and immigrants part of the same cluster. Danish HIV-TB co-infected patients were more often intravenous drug users than were co-infected immigrants (p < 0.0005). In conclusion, we found no evidence to suggest that the increase in TB incidence among young Danes was caused by the HIV-epidemic or transmission from immigrants. TB among HIV-positive Danes is most often due to recent infection. The patients often belong to a subpopulation living in Copenhagen characterized by intravenous drug use.