Specific and rapid detection methods for spinal tuberculosis, with sufficient sensitivity in HIV-1 co-infected individuals, are needed, to ensure early initiation of appropriate treatment to prevent physical disability and neurological fallout. In addition, understanding the systemic and local pathophysiology of spinal tuberculosis, and its interaction with HIV-1 infection, is crucial to guide future therapeutic interventions.

We prospectively enrolled adult patients presenting with signs and symptoms of suspected spinal tuberculosis, at Groote Schuur Hospital, between November 2020 and December 2021. TB diagnostic testing was performed on open and CT-guided spinal biopsies using Xpert MTB/RIF Ultra compared to gold standards TB culture and histology. A highly sensitive droplet digital PCR assay for detecting and quantifying Mycobacterium tuberculosis complex (MTBC) and HIV-1 DNA was tested. Plasma inflammatory proteins were measured to assess systemic inflammation.

Xpert Ultra had a high sensitivity of 94.7% and specificity of 100% for STB against TB culture and histology in both open and CT-guided biopsy samples. The ddPCR assay confirmed TB detection in 94% of patients with positive Xpert Ultra results. Four patients with negative TB diagnostic results had MTBC DNA detected by ddPCR. HIV-1 DNA was detected in the spinal tissues from all HIV-1-infected patients. MTBC DNA levels were significantly higher in HIV-1-co-infected spinal tissue samples (p< 0.01). We identified four biomarkers significantly associated with higher bacterial burden at the disease site (p< 0.01).

Xpert Ultra and MTBC ddPCR improve the detection of STB. DdPCR can be utilized as an additional, highly sensitive tool for detecting and quantifying Mtb, in pathological samples that may be paucibacillary. These findings provide novel diagnostic and pathophysiologic insight into STB, in the context of HIV-1 infection, and provide rationale to include these tests in hospital and research settings for patients from communities burdened by TB and HIV-1.

We investigated the response of chronic neck and shoulder pain to decompression of the carpal tunnel in 38 patients with whiplash injury. We also determined the plasma levels of substance P (SP) and calcitonin gene-related peptide (CGRP), which are inflammatory peptides that sensitise nociceptors. Compared with normal control subjects, the mean concentrations of SP (220 v 28 ng/l; p < 0.0001) and CGRP (400 v 85 ng/l; p < 0.0005) were high in patients with chronic shoulder and neck pain before surgery. After operation their levels fell to normal. There was resolution of neurological symptoms with improvement of pain in 90% of patients. Only two of the 30 with chronic neck and shoulder pain who had been treated conservatively showed improvement when followed up at two years.

In spite of having neuropathic pain arising from the median nerve, all these patients had normal electromyographic and nerve-conduction studies. Chronic pain in whiplash injury may be caused by ‘atypical’ carpal tunnel syndrome and responds favourably to surgery which is indicated in patients with neck, shoulder and arm pain but not in those with mild symptoms in the hand. Previously, the presence of persistent neurological symptoms has been accepted as a sign of a poor outcome after a whiplash injury, but our study suggests that it may be possible to treat chronic pain by carpal tunnel decompression.