# Diagnostic value of metagenomic next-generation sequencing in atypical brucellosis: a case report

## TL;DR

A case report shows how metagenomic sequencing helped diagnose a rare form of brucellosis without fever, leading to effective treatment.

## Contribution

First reported case of afebrile submandibular brucellosis diagnosed using metagenomic next-generation sequencing.

## Key findings

- mNGS identified Brucella suis in a submandibular abscess sample within 48 hours.
- Targeted therapy resolved symptoms in 6 days after mNGS-guided diagnosis.
- Combining mNGS with epidemiological history improved diagnostic accuracy in atypical brucellosis.

## Abstract

Brucellosis with atypical presentations, such as submandibular abscess without fever, is frequently misdiagnosed.

Metagenomic next-generation sequencing (mNGS) was applied to pus samples from a 47-year-old female with a treatment-refractory submandibular abscess and a history of livestock exposure; results were confirmed serologically.

Within 48 h, mNGS identified Brucella suis—representing, to our knowledge, the first reported afebrile submandibular infection caused by this pathogen. Targeted therapy with doxycycline and rifamycin led to symptom resolution within 6 days.

This case highlights that mNGS, combined with a thorough epidemiological history, can resolve diagnostic dilemmas in atypical brucellosis, guide precise treatment, and mitigate antibiotic misuse.