Treatment for radiographically active, sputum culture-negative pulmonary tuberculosis: A systematic review and meta-analysis.

BACKGROUND: People with radiographic evidence for pulmonary tuberculosis (TB), but negative sputum cultures, have increased risk of developing culture-positive TB. Recent expansion of X-ray screening is leading to increased identification of this group. We set out to synthesise the evidence for treatment to prevent progression to culture-positive disease. METHODS: We conducted a systematic review and meta-analysis. We searched for prospective trials evaluating the efficacy of TB regimens against placebo, observation, or alternative regimens, for the treatment of adults and children with radiographic evidence of TB but culture-negative respiratory samples. Databases were searched up to 18 Oct 2022. Study quality was assessed using ROB 2·0 and ROBINS-I. The primary outcome was progression to culture-positive TB. Meta-analysis with a random effects model was conducted to estimate pooled efficacy. This study was registered with PROSPERO (CRD42021248486). FINDINGS: We included 13 trials (32,568 individuals) conducted between 1955 and 2018. Radiographic and bacteriological criteria for inclusion varied. 19·1% to 57·9% of participants with active x-ray changes and no treatment progressed to culture-positive disease. Progression was reduced with any treatment (6 studies, risk ratio [RR] 0·27, 95%CI 0·13-0·56), although multi-drug TB treatment (RR 0·11, 95%CI 0·05-0·23) was significantly more effective than isoniazid treatment (RR 0·63, 95%CI 0·35-1·13) (p = 0·0002). INTERPRETATION: Multi-drug regimens were associated with significantly reduced risk of progression to TB disease for individuals with radiographically apparent, but culture-negative TB. However, most studies were old, conducted prior to the HIV epidemic and with outdated regimens. New clinical trials are required to identify the optimal treatment approach.

High resolution imaging and five-year tuberculosis contact outcomes.

Background: The evolution of tuberculosis (TB) disease during the clinical latency period remains incompletely understood. Methods: 250 HIV-uninfected, adult household contacts of rifampicin-resistant TB with a negative symptom screen underwent baseline 18F-Fluorodeoxyglucose positron emission and computed tomography (PET/CT), repeated in 112 after 5-15 months. Following South African and WHO guidelines, participants did not receive preventive therapy. All participants had intensive baseline screening with spontaneous, followed by induced, sputum sampling and were then observed for an average of 4.7 years for culture-positive disease. Baseline PET/CT abnormalities were evaluated in relation to culture-positive disease. Results: At baseline, 59 (23.6%) participants had lung PET/CT findings consistent with TB of which 29 (11.6%) were defined as Subclinical TB, and 30 (12%) Subclinical TB-inactive. A further 83 (33.2%) had other lung parenchymal abnormalities and 108 (43.2%) had normal lungs. Over 1107-person years of follow-up 14 cases of culture-positive TB were diagnosed. Six cases were detected by intensive baseline screening, all would have been missed by the South African symptom-based screening strategy and only one detected by a WHO-recommended chest X-Ray screening strategy. Those with baseline Subclinical TB lesions on PET/CT were significantly more likely to be diagnosed with culture-positive TB over the study period, compared to those with normal lung parenchyma (10/29 [34.5%] vs 2/108 [1.9%], Hazard Ratio 22.37 [4.89-102.47, p<0.001]). Conclusions: These findings challenge the latent/active TB paradigm demonstrating that subclinical disease exists up to 4 years prior to microbiological detection and/or symptom onset. There are important implications for screening and management of TB.

Mind the gap - Managing tuberculosis across the disease spectrum.

We currently have a binomial approach to managing tuberculosis. Those with active disease, ideally confirmed microbiologically, are treated with a standard 6-month, multi-drug regimen and those with latent infection and no evidence of disease with shorter, one or two drug regimens. Clinicians frequently encounter patients that fall between these two management pathways with some but not all features of disease and this will occur more often with the increasing emphasis on chest X-ray-based systematic screening. The view of tuberculosis as a spectrum of disease states is being increasingly recognised and is leading to new diagnostic approaches for early disease. However, the 6-month regimen for treating disease was driven by the duration required to treat the most extensive forms of pulmonary TB and shorter durations appear sufficient for less extensive disease. It is time undertake clinical trials to better define the optimal treatment for tuberculosis across the disease spectrum.

Risk factors for death among children aged 5-14 years hospitalised with pneumonia: a retrospective cohort study in Kenya.

INTRODUCTION: There were almost 1 million deaths in children aged between 5 and 14 years in 2017, and pneumonia accounted for 11%. However, there are no validated guidelines for pneumonia management in older children and data to support their development are limited. We sought to understand risk factors for mortality among children aged 5-14 years hospitalised with pneumonia in district-level health facilities in Kenya. METHODS: We did a retrospective cohort study using data collected from an established clinical information network of 13 hospitals. We reviewed records for children aged 5-14 years admitted with pneumonia between 1 March 2014 and 28 February 2018. Individual clinical signs were examined for association with inpatient mortality using logistic regression. We used existing WHO criteria (intended for under 5s) to define levels of severity and examined their performance in identifying those at increased risk of death. RESULTS: 1832 children were diagnosed with pneumonia and 145 (7.9%) died. Severe pallor was strongly associated with mortality (adjusted OR (aOR) 8.06, 95% CI 4.72 to 13.75) as were reduced consciousness, mild/moderate pallor, central cyanosis and older age (>9 years) (aOR >2). Comorbidities HIV and severe acute malnutrition were also associated with death (aOR 2.31, 95% CI 1.39 to 3.84 and aOR 1.89, 95% CI 1.12 to 3.21, respectively). The presence of clinical characteristics used by WHO to define severe pneumonia was associated with death in univariate analysis (OR 2.69). However, this combination of clinical characteristics was poor in discriminating those at risk of death (sensitivity: 0.56, specificity: 0.68, and area under the curve: 0.62). CONCLUSION: Children >5 years have high inpatient pneumonia mortality. These findings also suggest that the WHO criteria for classification of severity for children under 5 years do not appear to be a valid tool for risk assessment in this older age group, indicating the urgent need for evidence-based clinical guidelines for this neglected population.

The changing aetiology of eosinophilia in migrants and returning travellers in the Hospital for Tropical Diseases, London 2002-2015: An observational study.

INTRODUCTION: Determining the cause of eosinophilia in patients returning from the tropics continues to present a diagnostic challenge. The history, symptoms and degree of eosinophilia are often poor predictors of eventual diagnosis, but helminths are an important cause. The current British Infection Association recommendations use travel history to guide investigation of eosinophilia. However the global burden of helminth disease and travel patterns have changed over the last 3 decades and guidelines based on previous epidemiology need to be reviewed in the light of current data. METHODS: Consecutive patients presenting with, or referred for, investigation of eosinophilia were identified prospectively. Case notes, laboratory results and electronic records were reviewed for demographic and clinical data. Patients with an eosinophil count ≥0.50 × 109/L were included, and grouped based on lifetime history of travel to: West Africa, elsewhere in Africa, and the rest of the world. Results were compared to published data from 1997 to 2002 collected at the same centre. RESULTS: Of 410 patients who met the inclusion criteria, 407 had a documented travel history. Average yearly referrals for eosinophilia fell from 58 per year between 1997 and 2002, to 33 per year (2002-2015). The proportion of eosinophilia cases diagnosed with a parasitic cause fell from 64% to 50%, and yields for all parasitological investigations fell, the largest reduction in stool microscopy (20% yield to 9%) and day bloods for microfilariae (14% yield to 3%). Strongyloides stercoralis was the commonest diagnosis overall in our cohort, accounting for 50% of the total parasites diagnosed, and was present in 38% of patients from West Africa, 19% from rest of Africa, and 34% from rest of world; a relative increase compared to previous data. Schistosomiasis is slightly less common in those who had travelled to West Africa than the rest of Africa, and overall point prevalence has fallen from 33% (1997-2002) to 17% (2002-2015). Travellers were significantly less likely than patients who had immigrated to the UK to be diagnosed with any parasite (OR 0.54 95% CI 0.378-0.778 p = 0.0009). DISCUSSION: A parasitic cause will still be found in half of people returning from the tropics with an eosinophilia, but we observed a fall in the overall prevalence of parasitic diagnoses when compared with the earlier data. This may, in part, be explained by the impact of control programmes on the prevalence of parasites globally, especially filarial disease. S. stercoralis now represents the majority of parasites diagnosed in our cohort from all continents. We identified significantly higher rates of strongyloidiasis in immigrants than returning travellers. Despite the falling yields of stool microscopy and filarial serology the current guidelines based on travel history remain relevant with adequate yield.

The utility of a blood culture database to identify patients suitable for outpatient parenteral antibiotic treatment.

BACKGROUND: The clinical and cost-effectiveness of outpatient parenteral antimicrobial therapy (OPAT) services are well described. We used a blood culture database as a novel approach to case finding and determined its utility in identifying inpatients suitable for OPAT. METHODS: From December 2012 to November 2013, consecutive adult inpatients with bacteraemia, and those recruited to OPAT, were prospectively studied. Univariate and multivariate logistic regression analysis were used to investigate the association between bacteraemic patient characteristics and OPAT recruitment. RESULTS: There were 470 bacteraemic and 134 OPAT patients. The blood culture database identified 22 (16.4%; CI 10.5 to 23.6) additional patients suitable for OPAT, 4.7% (95% CI 3.0% to 7.0%) of the total bacteraemic cohort. 20 (90.9%) of these patients had community-acquired bacteraemia. Bacteraemic patients with urinary tract infections (UTIs), 11/157 (7.0%; 95% CI 3.5% to 12.2%) were most commonly recruited to OPAT and Escherichia coli was the most common blood culture isolate. In the E. coli bacteraemic subgroup, extended-spectrum ß-lactamase (ESBL) producers were significantly higher in the OPAT group, compared with the non-OPAT group, 9/11 (81.8%) vs 17/192 (8.9%), p<0.001. Among OPAT patients, there were no deaths within 30 days and no significant difference in relapse rates between bacteraemic and non-bacteraemic patients, 1/22 (4.6%) vs 5/112 (4.5%). In logistic regression analysis, there were no patient characteristics in the bacteraemic cohort that predicted recruitment to OPAT. In a subgroup analysis of patients with Gram-negative bacteraemia, ESBL production was strongly associated with OPAT recruitment, OR 5.85 (95% CI 1.94 to 17.58), p=0.002. CONCLUSIONS: A blood culture database proved a useful adjuvant to a clinical referral system, particularly for patients with community onset, multidrug resistant UTIs caused by ESBL producing E. coli. All bacteraemic patients recruited to OPAT received treatment safely and had good clinical outcomes.