How can gastro-intestinal tuberculosis diagnosis be improved? A prospective cohort study

Christopher Lowbridge,Jayaram Menon,Emma Schimann,Gayathri D Krishnan,Dawn Carmel Paul,Timothy William,Giri Shan Rajahram,Nagaraj Sriram,Soraya A M Fadhil,Aatish Patel,Anna P Ralph,Raman Muthu Karuppan

doi:10.1186/s12879-020-04983-y

Christopher Lowbridge, Jayaram Menon + Show 10 more

Open Access

https://doi.org/10.1186/s12879-020-04983-y

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Abstract

BackgroundGastrointestinal tuberculosis (TB) is diagnostically challenging; therefore, many cases are treated presumptively. We aimed to describe features and outcomes of gastrointestinal TB, determine whether a clinical algorithm could distinguish TB from non-TB diagnoses, and calculate accuracy of diagnostic tests.MethodsWe conducted a prospective cohort study of hospitalized patients in Kota Kinabalu, Malaysia, with suspected gastrointestinal TB. We recorded clinical and laboratory characteristics and outcomes. Tissue samples were submitted for histology, microscopy, culture and GeneXpert MTB/RIF®. Patients were followed for up to 2 years.ResultsAmong 88 patients with suspected gastrointestinal TB, 69 were included in analyses; 52 (75%) had a final diagnosis of gastrointestinal TB; 17 had a non-TB diagnosis. People with TB were younger (42.7 versus 61.5 years, p = 0.01) and more likely to have weight loss (91% versus 64%, p = 0.03). An algorithm using age < 44, weight loss, cough, fever, no vomiting, albumin > 26 g/L, platelets > 340 × 109/L and immunocompromise had good specificity (96.2%) in predicting TB, but very poor sensitivity (16.0%). GeneXpert® performed very well on gastrointestinal biopsies (sensitivity 95.7% versus 35.0% for culture against a gold standard composite case definition of confirmed TB). Most patients (79%) successfully completed treatment and no treatment failure occurred, however adverse events (21%) and mortality (13%) among TB cases were high. We found no evidence that 6 months of treatment was inferior to longer courses.ConclusionsThe prospective design provides important insights for clinicians managing gastrointestinal TB. We recommend wider implementation of high-performing diagnostic tests such as GeneXpert® on extra-pulmonary samples.

Highlights

Gastrointestinal tuberculosis (TB) is diagnostically challenging; many cases are treated presumptively
Samples were processed at the research laboratory at Queen Elizabeth Hospital (GeneXpert Mycobacterium tuberculosis (MTB)/RIF®), the pathology department of Queen Elizabeth Hospital and the Public Health Laboratory of Kota Kinabalu, Malaysia
Patient characteristics From a total of 88 patients suspected of having gastrointestinal TB on presentation at Queen Elizabeth Hospital and the Women’s and Children’s Hospitals, Kota Kinabalu, Sabah, between March 2015 and June 2017, consent for inclusion in the study was obtained from 77 patients

Summary

Introduction

Gastrointestinal tuberculosis (TB) is diagnostically challenging; many cases are treated presumptively. Gastrointestinal tuberculosis (TB) is a relatively uncommon form of TB which is defined as infection of the peritoneum, abdominal organs or abdominal lymphatic system [1]. TB control programs typically focus on pulmonary TB which is the predominant form of the disease; extra-pulmonary TB, in particular gastro-intestinal TB, is relatively neglected. This is likely due to it being more difficult to diagnose and lacking the transmission potential of smear-positive pulmonary TB. Extra-pulmonary TB, including gastrointestinal TB often represents the worst end of the TB disease severity spectrum, with poorer prognosis and treatment outcomes [2]. Sabah State, located in Malaysian Borneo, has a high burden of disease, accounting for approximately 20 to 30% of Malaysia’s TB cases despite having only 10% of Malaysia’s population [4, 5]

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