# Recurrent Cough in a Pediatric Patient From China: A Case Report of Bordetella pertussis Infection With Genomic Insights

## TL;DR

A six-year-old girl in China had a persistent cough caused by multiple infections, including drug-resistant Bordetella pertussis, which was identified using genomic sequencing.

## Contribution

The case highlights the use of targeted sequencing to detect co-infections and antibiotic resistance in a pediatric patient with persistent cough.

## Key findings

- The patient had co-infections with Bordetella pertussis, human rhinovirus A, adenovirus type 2, and SARS-CoV-2.
- An A2047G mutation in B. pertussis 23S rRNA gene indicated macrolide resistance, but it disappeared in later tests.
- Targeted sequencing helped identify the cause and resistance, leading to more effective treatment.

## Abstract

We report the case of a six-year-old girl from Zhangjiajie City, Hunan Province, with a history of recurrent cough lasting for a month, characterized by paroxysmal coughing, expectoration, and intermittent fever, with the highest temperature reaching 39℃. Recurrent coughing in pediatric patients presents diagnostic challenges when multiple pathogens and antibiotic resistance are involved. Despite receiving traditional Chinese medicine and antibiotic treatments, the patient’s symptoms persisted. The initial diagnosis failed to identify the cause, although blood tests showed elevated levels of C-reactive protein and serum amyloid A, and chest X-rays indicated signs of bronchopneumonia. The patient tested positive for respiratory syncytial virus and Haemophilus influenzae, with a Mycoplasma pneumoniae antibody titer of 1:40. Despite treatment with azithromycin, ambroxol, and nebulization, the cough symptoms did not improve, leading to multiple hospital admissions. Subsequent targeted sequencing confirmed infections by Bordetella pertussis, human rhinovirus A, adenovirus type 2, and SARS-CoV-2 at different stages. Notably, genomic analysis during the first hospital stay discovered an A2047G mutation in the 23S rRNA gene of B. pertussis, indicating resistance to macrolide drugs; however, subsequent tests showed that this mutation had disappeared. This case highlights the complexity of diagnosing and treating persistent cough in pediatric patients and underscores the importance of targeted next-generation sequencing in identifying resistance and co-infections, ultimately enabling more precise and effective treatment strategies for challenging respiratory infections in children.