First Fatal Cases due to Escherichia coli O157 and Campylobacter jejuni subsp. jejuni Outbreak Occurred in Southern...

Area of Science:

• Microbiology
• Infectious Diseases
• Public Health

Background:

• A cluster of severe gastrointestinal illnesses, including diarrhea, vomiting, and fever, affected four children from the same school in Brazil in December 2019.
• One child's mother was diagnosed with hemolytic uremic syndrome (HUS), a serious complication often associated with bacterial infections.
• These initial cases preceded the identification of specific bacterial pathogens and the tragic outcomes.

Purpose of the Study:

• To identify the causative agents of a severe outbreak of illness and death in children in Brazil.
• To investigate the potential sources and transmission routes of the identified pathogens.
• To determine the role of specific bacteria, Escherichia coli O157 NM and Campylobacter jejuni, in the outbreak's severity and fatalities.

Main Methods:

• Bacterial isolation and identification from clinical samples (stool), food, environmental sources, and tap water.
• Pulsed-field gel electrophoresis (PFGE) to compare the genetic profiles of bacterial isolates.
• Clinical assessment of symptoms and patient outcomes, including cause of death.

Main Results:

• Escherichia coli O157 NM was isolated from one child's stool.
• Campylobacter jejuni isolates were found in the feces of affected children, raw food, environmental samples, and tap water.
• Identical PFGE profiles for C. jejuni isolates from feces and tap water indicated a common source of infection.
• Two children died from renal and respiratory failure, respectively. Deaths were attributed to E. coli O157 NM, with potential contribution from C. jejuni coinfection.
• This outbreak represented the first registered deaths attributed to E. coli O157 NM in Brazil.

Conclusions:

• Escherichia coli O157 NM was identified as the primary cause of a fatal outbreak in Brazil.
• Campylobacter jejuni coinfection may have exacerbated the severity of the clinical presentation and contributed to the fatalities.
• The findings highlight the public health risk posed by these pathogens and the importance of identifying transmission sources, such as contaminated tap water.