Use of the Xpert^® MTB/RIF assay for diagnosing pulmonary tuberculosis comorbidity and multidrug‐resistant TB in obstetrics and gynaecology inpatient wards at the University Teaching Hospital, Lusaka, Zambia

Abstract

OBJECTIVESIn high-tuberculosis (TB)-endemic countries, comorbidity of pulmonary TB in hospitalised patients with non-communicable diseases is well documented. In this study, we evaluated the use of the Xpert® MTB/RIF assay for the detection of concomitant pulmonary TB in patients admitted to the University Teaching Hospital, Lusaka, Zambia, with a primary obstetric or gynaecological condition.METHODSThe Study population were inpatients admitted with a primary obstetric or gynaecological problem who had a concomitant cough and were able to expectorate a sputum sample. Sputum samples from 94 patients were analysed for the presence of Mycobacterium tuberculosis (M.tb) by standard smear microscopy, MGIT culture, MGIT drug-susceptibility testing (DST) and the Xpert® MTB/RIF assay. The sensitivity and specificity of the Xpert® MTB/RIF assay were evaluated against the culture gold standard.RESULTSTwenty-six of 94 (27.7%) patients had culture-confirmed pulmonary TB. The Xpert® MTB/RIF assay had a sensitivity of 80.8% [95% CI: 60.0–92.7%]) compared against MGIT culture. The Xpert® MTB/RIF assay was more sensitive than sputum smear microscopy (21/26 (80.8%) vs. 13/26 (50.0%), P = 0.02) and detected an additional eight culture-confirmed cases. Culture DST analysis identified two monoresistant M.tb strains: one resistant to rifampicin (rifampicin sensitive by the Xpert® MTB/RIF assay) and one to ethambutol. HIV infection was linked with a 3-fold increase in risk of TB, accounting for 87.5% (21/24) of TB cases. 50% of cases presented as comorbidities with other communicable diseases (CDs) and non-communicable diseases (NCDs).CONCLUSIONSAs an alternative to sputum microscopy, the Xpert® MTB/RIF assay provides a sensitive, specific and rapid method for the diagnosis of pulmonary TB in obstetric or gynaecological inpatients. Pulmonary TB is an important cause of concomitant comorbidity to the obstetric or gynaecological condition necessitating admission. TB and HIV comorbidities with other communicable and non-communicable diseases were also common. More proactive screening for TB comorbidity is required in obstetric and gynaecological wards.

Maternal and perinatal mortality and morbidity associated with tuberculosis during pregnancy and the postpartum period: a systematic review and meta‐analysis

“…23 In low and middle income countries, where TB may represent the greatest burden, pregnancy may be one of the few opportunities to assess a woman's health. 26,27 However, there are no guidelines for routine screening for active TB in pregnancy. 4 Different tests have been used in antenatal care, such as symptom check, routine sputum smear examination, 24,25 and the Xpert â MTB/RIF assay.…”

High HIV and active tuberculosis prevalence and increased mortality risk in adults with symptoms of TB: a systematic review and meta‐analyses

“…For HIV prevalence outcome, 47/62 (75.8%) of the studies had low risk of bias while 15/62 (24.2%) had high or unclear risk of bias (). Studies were categorized as having high risk of bias for the HIV prevalence due to poor determination of HIV status (6/62, 9.7%); unclear or low uptake of HIV testing (8/62, 12.9%); and not describing how HIV status was determined (1/62, 1.6%) . Most (53/59, 89.8%) studies had low risk of bias for the estimation of TB prevalence.…”

“…Studies at primary care level were either diagnostic evaluations [23][24][25][26][27][28][29][30], programme evaluations [31][32][33] or other cross-sectional designs [34][35][36][37]. Studies among hospital inpatients were predominantly diagnostic evaluations [38][39][40][41].…”

Transmission and Institutional Infection Control of Tuberculosis

“…Under high-burden conditions, TB is commonly missed in persons presenting with unrelated conditions (Willingham et al 2001;Bates et al 2012Bates et al , 2013. Under low-burden conditions, the diagnosis is less likely to be considered even with classical symptoms.…”