Diagnostic Accuracy of Lung and Abdominal Ultrasound for Tuberculosis in a German Multicenter Cohort of Patients With Presumed Tuberculosis Disease

Abstract

Background: There is limited evidence on point-of-care ultrasound for tuberculosis (TB), but studies suggest high sensitivity, especially for lung ultrasound (LUS). However, insufficient data are available on specificity of the examination and its generalizability to a broader patient population.

Aims: Our study aimed to establish accuracy for lung, chest, and abdominal ultrasound, individually and in combination, for TB diagnosis.

Methods: We conducted a prospective diagnostic accuracy study among consecutive adult out- and inpatients with probable TB in three German referral hospitals. We applied a comprehensive standardized ultrasound protocol. TB diagnosis was established by a microbiological reference standard including polymerase chain reaction and culture.

Results: A total of 102 participants originating from 30 different countries were enrolled. HIV prevalence was 7/99 (7%) and 73/102 (72%) had confirmed TB. TB was limited to the lungs in 15/34 (44%) of refugees and 27/39 (69%) in nonrefugees. Focused assessment with sonography for HIV-associated tuberculosis had a sensitivity of 40% (95% confidence interval [CI], 30-52) and specificity of 55% (95% CI, 38-72). Additional findings, such as small subpleural consolidations on LUS had a high sensitivity (88%; 95% CI, 78-93), but a low specificity (17%; 95% CI, 8-35). Larger consolidations in the lung apices had a sensitivity of 19% (95% CI, 12-30) and a specificity of 97% (95% CI, 83-100).

Conclusions: Our study establishes the first data on LUS performance against a comprehensive reference standard. Overall, our data suggest that ultrasound does not meet the requirements for triage but previously described and novel ultrasound targets in combination could aid in the clinical decision making.Registry: DRKS00026636.

Keywords: diagnosis; lung ultrasound; migrant medicine; point-of-care ultrasound; tuberculosis.

Figure 1.

schematic of lung zones and probe movement. Zone 1/2: example for longitudinal sweep; zone 7/8: example for intercostal sweeps.

Figure 2.

Flow chart for study recruitment and reference standard categories. Abbreviations: CRS, composite reference standard; eMRS extended MRS; MRS, microbiological reference standard; TB, tuberculosis; UKC, University Hospital Cologne; UKF, University Hospital Frankfurt; UKHD, University Hospital Heidelberg. *UKHD n = 83, UKF n = 19, UKC n = 6.

Figure 3.

Tuberculosis location and refugee status. Venn diagrams for location of TB in all participants, self-identified refugees and nonrefugees. A (left), all TB cases. B (center), nonrefugee TB cases. C (right), refugee TB cases. Abbreviations: EPTB, extrapulmonary tuberculosis; PTB, pulmonary tuberculosis; PTB + EPTB: concurrent PTB and EPTB; TB, tuberculosis.

Figure 4.

Ultrasound case studies. A, Female in her 40 s, DM–, HIV–, MRS+ with numerous small peritoneal nodules seen from transcostal view. B, C, Man in his 20s, eMRS+, internal mammary enlarged lymph node (1.9 × 0.8 cm) (B), and omental cake with hypoechoic inclusions (C, inclusions single arrows). D, Female in her 20s, after kidney transplant 5 y ago with unlikely TB and disseminated bartonellosis (tissue-PCR positive) with numerous small and large hypoechoic spleen lesions (maximum 2.8 cm). E + F: Female in her 40s, HIV+, post-TB with irregular treatments in the past, now MRS+ (pre-XDR), widespread SPC _{< 1cm} and SPC _{≥ 1cm} with single SPC showing oval shape (E), other lesions resembled shreds (F). G + H: Man in his 40s with large cell neuroendocrine lung carcinoma with pulmonary aspergillosis with SPC _{< 1cm} (G) and SPC _{≥ 1cm} (H, curved array). Abbreviations: CRS, composite reference standard; DM, diabetes mellitus; eMRS, extended microbiological reference standard; MRS, microbiological reference standard; SPC, subpleural consolidation; TB, tuberculosis; XDR, extensively drug resistant.