An international study involving data from 261 bloodstream infections caused by bacteria of the genus Campylobacter has found that people with humoral immunodeficiencies, which are immune system disorders that affect antibody production, are at particularly high risk of recurrent infections caused by this bacterium. The research, conducted with the participation of researchers from the Fight Infections Foundation, also warns that antibiotic resistance in some species of this bacterium may exceed 90%.
The study, published in the journal Open Forum Infectious Diseases, analysed cases diagnosed between 2009 and 2024 across 27 hospitals in five countries: Spain, Italy, France, the United Kingdom and Brazil. This makes it one of the largest studies on Campylobacter bacteraemia described to date.
Although this bacterium is primarily known for causing gastroenteritis and diarrhoea, in some cases it can enter the bloodstream and cause serious infections. This risk is particularly significant in immunocompromised people. In fact, almost two-thirds of the cases analysed involved patients with some form of immunodeficiency.
Nine out of ten recurrent infections occur in patients with antibody deficiencies
The researchers observed that recurrent infections occurred in 8% of cases. However, the risk was considerably higher among patients with immune system disorders that impair antibody production, who accounted for 19 of the 21 recurrent episodes recorded in the study.
This phenomenon was particularly common among people who have difficulty producing antibodies, a key component of the immune system’s defence against infections, as well as among patients with blood disorders who had received treatments that affect these defences.
In addition, people with humoral immunodeficiencies were more likely to have a history of Campylobacter infections and previous episodes of bacteraemia, reinforcing the key role of antibodies in controlling this microorganism.
More than 90% of Campylobacter coli strains are resistant to antibiotics
The study also describes an increase in cases caused by Campylobacter coli, which rose from accounting for 12% of episodes during the earlier years of the study to almost 27% in the most recent period.
The results show that this species has very high levels of resistance to antibiotics commonly used to treat these infections. Specifically, more than 90% of the Campylobacter coli strains analysed were resistant to ciprofloxacin, while more than half were resistant to azithromycin, two of the antibiotics most commonly used to treat this bacterium.
The authors point out that this situation represents a growing clinical challenge and highlight the need to optimise treatment strategies for the most vulnerable patients.
An infection with a low mortality rate but a high recurrence rate
Although overall mortality at 30 days was below 10%, the researchers highlight that the main problem in this patient group was recurrence of the infection, which can occur weeks or even months after the initial episode.
According to the authors, the findings highlight the need for further studies to better understand the mechanisms that contribute to these recurrent infections and to determine the optimal duration of antibiotic treatment to prevent them.
Share