Pasteurella multocida Infections with Unusual Modes of Transmission from Animals to Humans: A Study of 79 Cases with 34 Nonbite Transmissions.

Pasteur discovered the causative agent of fowl cholera (Pasteurella multocida) in 1880. Since then, multiple zoonotic infections affecting humans have been reported. P. multocida infections usually result from bites of cats or dogs. The earliest reports of nonbite transmissions (NBTs) were attributed to cat scratches and lung colonization. More recently, multiple modes of unusual NBTs have been reported, including animal exposures with no direct contact. Here, we report 79 cases of pet-associated infections, with 34 NBTs. Previously unreported and unsuspected, novel modes of NBTs presented include stepping on dog drool infecting a submetatarsal ulcer, contamination of a wound by socks covered with cat hair and dander resulting in P. multocida bacteremia, stumbling over a dog and falling while drunk and abrasions contaminated with dog saliva resulting in wound infection, and severe epiglottitis and supraglottitis after eating peanut butter and crackers half eaten by a dog. Cat bites were more common than dog bites. Both bite and nonbite infections were more common in the elderly, with more older patients in the nonbite group. Upper extremity bites were more than lower extremity bites for both cats and dogs. NBTs were associated with more co-morbidities and resulted in more life-threatening infections than bites, confirming the findings of a prior smaller series. Open wounds were the most common point of entry for nonbite infections, with majority in the lower extremity. Based on this study and prior reports, pet owners must protect open wounds and individuals with certain underlying conditions and infants should avoid pet exposure completely. Our findings and animal transmission of bite and nonbite P. multocida infections reported in literature are summarized.

Circulation of a community healthcare-associated multiply-resistant meticillin-resistant Staphylococcus aureus lineage in South Yorkshire identified by whole genome sequencing.

BACKGROUND: A cluster of seven cases of skin and wound infections caused by a multiply resistant meticillin-resistant Staphylococcus aureus (MRSA) were detected in a small-town community in South Yorkshire. Initial microbiological investigations showed that all isolates belonged to a spa type observed rarely in England (t1476). AIM: To describe the epidemiology of t1476 MRSA in South Yorkshire. METHODS: Retrospective and prospective case ascertainment was promoted through communication with local microbiology laboratories. Public health investigation included a detailed review of clinical notes for a subset of nine cases. Genomic and phylogenetic analysis was undertaken on t1476 MRSA. FINDINGS: Thirty-two cases of t1476 MRSA infection or colonization were identified between December 2014 and February 2018. Cases were older adults (aged 50-98 years). Healthcare exposures for a subset of nine cases indicated frequent contact with a team of district nurses, with all but one case receiving treatment on the same day as another case prior to their own diagnosis. No cases were admitted to hospital at the time of specimen collection. Despite detailed investigations, no carriers were detected among district nursing staff. A long-term carrier/super-shedder was not found. Phylogenetic analysis indicated that t1476 MRSA cases from South Yorkshire were monophyletic and distant from both MRSA of the same lineage from elsewhere in the UK (N = 15) and from publicly available sequences from Tanzania. CONCLUSION: Genomic and epidemiological analyses indicate community-based transmission of a multiply resistant MRSA clone within South Yorkshire introduced around 2012-2013, prior to the detection of a spatial-temporal cluster associated with a distinct risk group. Surveillance data indicate continued circulation.

Acinetobacter - the trojan horse of infection control?

BACKGROUND: Five cases of multi-resistant Acinetobacter baumanii (MRA) producing OXA-23 and OXA-51 occurred in a regional burn intensive care unit (BICU). Three were repatriated from other parts of the world (Dubai and Mumbai) and colonized on admission. Despite optimal precautions, two patients acquired MRA. Both had been nursed in the same room. METHODS: Multi-disciplinary outbreak investigation of MRA in a regional BICU. FINDINGS: The mechanism of transfer for the first case is thought to have been contaminated air from theatre activity releasing MRA bacteria into the communal corridor. No MRA patients went to theatre between the first and second acquired cases. The mechanism of transfer for the second case is thought to have been via a shower unit that was decontaminated inadequately between patients. CONCLUSION: In an outbreak where contact precautions and environmental cleaning are optimal, it is important to give careful consideration to other mechanisms of spread. If there is a failure to do this, it is likely that the true causes of transmission will not be addressed and the problem will recur. It is recommended that burn theatres within burn facilities should be designed to operate at negative pressure; this is the opposite of normal operating theatre ventilation. Where showers are used, both the shower head and the hose should be changed after a patient with a resistant organism. The role of non-contact disinfection (e.g. hydrogen peroxide dispersal) should be reconsidered, and constant vigilance should be given to any 'trojan horse' item in the room.

An outbreak of multidrug-resistant Pseudomonas aeruginosa in a burns service in the North of England: challenges of infection prevention and control in a complex setting.

BACKGROUND: Burns patients are at high risk of nosocomial infection, and Pseudomonas aeruginosa is one of the most common causes of wound and systemic infections resulting in significant morbidity and mortality in burns patients. AIM: To describe an outbreak of multidrug-resistant P. aeruginosa (MDR-Pa) at a specialist burns service and highlight the challenges in identifying the reservoir of infection despite extensive epidemiological, microbiological, and environmental investigations. METHODS: Multi-disciplinary outbreak control investigation. FINDINGS: Following an inter-hospital transfer of a burns patient from another country, an admission screen revealed that the patient was colonized with MDR-Pa. Subsequently nine more patients contracted MDR-Pa in the period from November 2015 to September 2017. Given the relatively long gap between confirmation of the index and subsequent cases, it was not possible to identify with certainty the reservoirs and mechanisms of spread of infection, although contamination of the burns service environment and equipment are likely to be contributory factors. CONCLUSION: Preventing infection transmission in specialist burns services is highly challenging, and it may not always be possible to identify and eradicate the reservoirs of infection for P. aeruginosa outbreaks. Our study supports the literature, providing additional evidence that inanimate, common contact surfaces play an important role in nosocomial transmission of P. aeruginosa. These surfaces should either be decontaminated efficiently between patient contacts or be single patient use. Enhanced vigilance is crucial, and, with strict adherence to infection prevention and control procedures, it is possible to reduce the risk of acquisition and spread of infection in patients.

Bacteria aerosol spread and wound bacteria reduction with different methods for wound debridement in an animal model.

Debridement is essential in wound treatment to remove necrotic tissue and wound bacteria but may lead to bacteria spread by aerosolization. This study investigated the wound bacterial reduction and bacterial transmission induced by debridement using curette, plasma-mediated bipolar radiofrequency ablation (Coblation®) or hydrodebridement (Versajet®). Full thickness dermal wounds in porcine joint specimens inoculated with S. aureus were debrided with curette, Coblation, Versajet, or were left untreated. During and after debridement, aerosolized bacteria were measured and to assess wound bacterial load, quantitative swab samples were taken from each wound. Only Coblation was able to reduce the bacterial load of the wound significantly. Versajet debridement resulted in a significant bacterial aerosolization, but this was not the case with Coblation and curette debridement. This study shows that Coblation is a promising wound debridement method, which effectively reduces the wound bed bacterial load without the risk of bacterial aerosolization.

The evaluation of nasal mupirocin to prevent Staphylococcus aureus burn wound colonization in routine clinical practice.

BACKGROUND: Staphylococcus aureus wound colonization frequently occurs in patients with burns and can cause impaired wound healing. Nasal mupirocin application may contribute to the reduction of burn wound colonization of endogenous origin, whereas colonization by the exogenous route can be reduced by blocking cross-infection from other sources. In this study we evaluated whether the implementation of routine treatment of patients and burn center personnel using nasal mupirocin ointment reduces S. aureus burn wound colonization. METHODS: We composed three study groups, consisting of a control period (Control), a mupirocin period (MUP), in which patients with burns were all receiving nasal mupirocin at admission, and a mupirocin+personnel period (MUP+P), in which we also screened the burn center personnel and decolonized S. aureus carriers by nasal mupirocin. RESULTS: The patients who carried S. aureus in their nose and did not have S. aureus burn wound colonization at admission were considered as patients susceptible for the use of nasal mupirocin. In these patients, the S. aureus burn wound colonization rate was the same in all study groups. S. aureus nasal carriage was a significant independent risk factor for burn wound colonization (OR: 3.3; 95% CI: 1.4-7.6) when analyzed within the three study groups. CONCLUSION: Although S. aureus carriage is a significant risk factor for developing burn wound colonization, the routine use of nasal mupirocin did not contribute to a reduction of burn wound colonization.

Isolation of Leclercia adecarboxylata from a wound infection after exposure to hurricane-related floodwater.

A man in his early 80s presented to our emergency department with painless redness and swelling in his right leg. One week prior, he cleaned up floodwater in his basement after Hurricane Irene passed the Mid-Atlantic region of the USA in August 2011. Physical examination included large purple bullae and raised concern for necrotising fasciitis. Wound culture revealed a polymicrobial infection including Leclercia adecarboxylata.

[Vibrio infections from food and sea water. Introducing the "VibrioNet"]. / Vibrio-Infektionen durch Lebensmittel und Meerwasser. Das Netzwerk "VibrioNet" stellt sich vor.

Vibrio is a genus of bacteria present in surface and coastal waters as well as in marine organisms worldwide. In many countries, pathogenic Vibrio species are a main cause of bacterial diarrhea, which may result from comsumption of contaminated seafood and fish products or from drinking contaminated water. Vibrio infections may also gain in importance in our regions due to global warming and the increase in the world trade of seafood. The research network "VibrioNet" studies pathogenic Vibrios in the marine environment and in seafood consumed by humans as a potential, new emerging zoonotic agent. An assessment of the risk arising from pathogenic non-cholera-vibrios in central Europe is the target of a multidisciplinary research effort. The research network will be strengthened by cooperations with international partners from countries in which Vibrio infections play a major role (Bangladesh, Chile, India, Thailand, and Vietnam).

Burn wounds infected by contaminated water: case reports, review of the literature and recommendations for treatment.

First-aid education for the management of burns advocates cool running water over burnt skin to limit soft tissue damage. However, the water used may itself constitute a risk. We report three cases of severe invasive and necrotizing infection in patients who used or immersed themselves in contaminated water in an attempt to extinguish the fire following acute major burns. Wound cultures from all patients yielded Aeromonas hydrophila and two yielded Bacillus cereus. One patient had a complex polymicrobial infection, including zygomycosis with Rhizomucor variabilis. All patients were treated aggressively with wound débridement, including one patient who required bilateral lower limb amputations to control progressive infection. All infections were successfully treated and all patients survived their burn injuries. We review the management of burns complicated by exposure to contaminated water leading to burn wound infections. We describe commonly reported organisms from various water sources, the appropriate initial empirical antimicrobial chemotherapy and present the clinician with a proposed algorithm for managing these serious infections.

Multidrug-resistant organisms in military wounds from Iraq and Afghanistan.

Mortality from battlefield wounds has historically declined, thanks to better surgical management, faster transport of casualties, and improved antibiotics. Today, one of the major challenges facing U.S. military caregivers is the presence of multidrug-resistant organisms in orthopaedic extremity wounds. The most frequently identified resistant strains of bacteria are Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter calcoaceticus-baumannii complex. Overuse of broad-spectrum antibiotics may be an important factor in building resistant strains. Acinetobacter infections appear to hospital-acquired and not from an initial colonization of the injury. More research is required to give military physicians the tools they require to reduce the infection rate and defeat multidrug-resistant organisms.

Five-year review of infections in a burn intensive care unit: High incidence of Acinetobacter baumannii in a tropical climate.

A 5-year review of nosocomial infections, bacteraemia and wound colonization in patients admitted to a burn intensive care unit from June 2001 to May 2006 was carried out. All patients required intubation at some point, and ICU support. Data on bacterial and fungal isolates were entered prospectively into a hospital-wide computerized database. Nosocomial infections (NIs) were defined using standard CDC criteria. Seventy-six patients were admitted during the study period, with 57 qualifying for analysis. Forty-two patients (74%) developed 137 NIs, with 240 NIs/100 admissions. The most common NI was pneumonia (43%), followed by burn wound infection (34%), primary bloodstream infection (20%) and urinary tract infection (3%). The device specific rate of pneumonia was 143 infections per 1000 ventilator days. There were 113 episodes of bacteraemia and 173 episodes of wound colonization without infection. The most common organisms causing nosocomial infections were Acinetobacter sp. (n=33), followed by methicillin resistant Staphylococcus aureus (MRSA) (n=24) and Pseudomonas aeruginosa (n=22). A. baumannii isolates were highly multiresistant, with 82 distinct strains isolated from 47 patients (82% of patients). Data from this and other studies supports the hypothesis that A. baumannii is more common in tropical, warm climes necessitating vigorous infection control measures to optimise patient outcome.

Study of the environmental effect of a commercial wound cleanser used with different mechanical forces.

Important improvements have been made in wound care over the last decade. However, few data are available on the influence that these have outside their intended use. This study aimed to clarify the effects of the use of wound cleansers on bacterial contamination of the immediate surroundings. Little evidence was found from either laboratory or clinical settings that wound-derived micro-organisms become airborne during wound cleansing. Bacterial dispersion around wounds may be attributed to general activity rather than wound cleansing. If simple precautions are taken, risks for personnel and patients in hospitals and consultation rooms during wound cleansing can be minimized.

Pseudomonas infections in the thermally injured patient.

Pseudomonas aeruginosa, remains a serious cause of infection and septic mortality in burn patients, particularly when nosocomially acquired. A prototypic burn patient who developed serious nosocomially acquired Pseudomonas infection is described as an index case which initiated investigations and measures taken to identify the source of the infection. The effect of changes in wound care to avoid further nosocomial infections was measured to provide data on outcome and cost of care. The bacteriology of Pseudomonas is reviewed to increase the burn care providers understanding of the behaviour of this very common and serious pathogen in the burn care setting, before reviewing the approach to detection of the organism and treatment both medically and surgically. After controlling the nosocomial spread of Pseudomonas in our burn unit, we investigated the morbidity and mortality associated with nosocomial infection with an aminoglycoside resistant Pseudomonas and the associated costs compared to a group of case-matched control patients with similar severity of burn injury, that did not acquire resistant Pseudomonas during hospitalization at our institution. We found a significant increase in the mortality rate in the Pseudomonas group compared to controls. The morbidity in terms of length of stay, ventilator days, number of surgical procedures, and the amount of blood products used were all significantly higher in the Pseudomonas group compared to controls. Costs associated with antibiotic requirements were also significantly higher in the Pseudomonas group. Despite this increased resource consumption necessary to treat Pseudomonas infections, these efforts did not prevent significantly higher mortality rates when compared to control patients who avoided infection with the resistant organism. Thus, in addition to the specific measures required to identify and treat nosocomial Pseudomonas infections in burn patients, prevention of infection through modification of treatment protocols together with continuous infection control measures to afford early identification and eradication of nosocomial Pseudomonas infection are critical for cost-effective, successful burn care.