Non-cholera Vibrio spp. invasive infections in the summer following May 2023 flood disaster in Romagna, Italy: a case series.

Non-cholera Vibrio spp. includes ubiquitous organisms living in aquatic environments. Their occurrence is associated with global warming and meteorological disasters. In May 2023 the Romagna region, Italy, was affected by severe floods. In the following 15 weeks we observed 5 patients with invasive infections caused by V. vulnificus (3/5) and V. harveyi (2/5). All patients (median age 77 years) had medical comorbidities and shared exposure to seawater. Two patients needed surgery; 2 died. In conclusion, we observed an increased burden of Vibrio spp. invasive infections after May 2023 floods, affecting old patients with predisposing medical conditions.

Wound infection with Vibrio harveyi following a traumatic leg amputation after a motorboat propeller injury in Mallorca, Spain: a case report and review of literature.

BACKGROUND: Vibrio spp. are aquatic bacteria that are ubiquitous in warm estuarine and marine environments, of which 12 species are currently known to cause infections in humans. So far, only five human infections with V. harveyi have been reported. CASE PRESENTATION: A 26-year old patient was transferred to our center by inter-hospital air transfer from Mallorca, Spain. Seven days before, he had suffered a complete amputation injury of his left lower leg combined with an open, multi-fragment, distal femur fracture after he had been struck by the propeller of a passing motorboat while snorkeling in the Mediterranean Sea. On admission he was febrile; laboratory studies showed markedly elevated inflammatory parameters and antibiotic treatment with ampicillin/sulbactam was initiated. Physical examination showed a tender and erythematous amputation stump, so surgical revision was performed and confirmed a putrid infection with necrosis of the subcutaneous tissue and the muscles. Tissue cultures subsequently grew V. harveyi with a minimal inhibitory concentration (MIC) of 16 mg/L for ampicillin, and antibiotic treatment was switched to ceftriaxone and ciprofloxacin. Throughout the following days, the patient repeatedly had to undergo surgical debridement but eventually the infection could be controlled, and he was discharged. CONCLUSIONS: We report the first human infection with V. harveyi acquired in Spain and the second infection acquired in the Mediterranean Sea. This case suggests that physicians and microbiologists should be aware of the possibility of wound infections caused by Vibrio spp. acquired in the ocean environment, especially during hot summer months. Since Vibrio spp. preferentially grow at water temperatures above 18 °C, global warming is responsible for an abundance of these bacteria in coastal waters. This will likely lead to a worldwide increase in reports of Vibrio-associated diseases in the future.

Impact of climate change on waterborne infections and intoxications.

Progressive climate change holds the potential for increasing human health risks from waterborne infections and intoxications, e. g. through an increase in pathogen concentrations in water bodies, through the establishment of new pathogens or through possible changes in pathogen properties. This paper presents some examples of potential impacts of climate change in Germany. Non-cholera Vibrio occur naturally in seawater, but can proliferate significantly in shallow water at elevated temperatures. In the case of Legionella, climate change could lead to temporary or longer-term increased incidences of legionellosis due to the combination of warm and wet weather. Higher temperatures in piped cold water or lower temperatures in piped hot water may also create conditions conducive to higher Legionella concentrations. In nutrient-rich water bodies, increased concentrations of toxigenic cyanobacteria may occur as temperatures rise. Heavy rainfall following storms or prolonged periods of heat and drought can lead to increased levels of human pathogenic viruses being washed into water bodies. Rising temperatures also pose a potential threat to human health through pathogens causing mycoses and facultatively pathogenic micro-organisms: increased infection rates with non-tuberculous mycobacteria or fungi have been documented after extreme weather events.