Cat bite: an injury not to underestimate

The polymicrobial nature of the oral cavity and claws of cats diagnosed by mass spectrometry and next-generation sequencing

Close contact between cats and humans increases the risk of transmission of zoonotic pathogens, through bites and scratches due to the complexity of microorganisms in the oral and nail microbiotas of felines. This study investigated the presence of bacteria and fungi in the oral cavity and claws of 100 apparently healthy cats using conventional and selective microbiological culture media, and next-generation sequencing (NGS) and mass spectrometry (MALDI-TOF MS). Furthermore, antimicrobial susceptibility testing of bacteria isolates was performed by disc diffusion method. In total, 671 bacteria and 33 yeasts were identified by MALDI-TOF MS. Neisseria animaloris (10.8 %), Staphylococcus felis (8.5 %), and Pasteurella multocida (7 %) were the most prevalent bacteria in oral cavity samples (n = 343), while the most common yeast (n = 19) was Candida albicans (68.4 %). Staphylococcus pettenkoferi (13.4 %), Staphylococcus felis (6.4 %), and Staphylococcus simulans (5.8 %) were the prevalent bacteria identified in the claw samples (n = 328), while Rhodotorula mucilaginosa (57.2 %) was the most common yeast (n = 14). NGS predominantly identified the genera Moraxella, Neisseria, Pasteurella, and Fusobacterium in oral cavity samples, whereas enterobacteria and staphylococci were prevalent in nail bed samples. In addition, the genera Capnocytophaga and Bartonella were identified, which have been described in serious human infections secondary to feline aggressions. Levofloxacin, marbofloxacin, and amoxicillin/clavulanic acid were the most effective drugs against the main groups of bacteria identified. Multidrug resistance was observed in 17 % of the bacterial isolates. Furthermore, three staphylococci harboring the methicillin resistance gene mecA were identified. We highlight the complexity of microorganisms inhabiting the oral/claw microbiotas of cats, the high resistance rate of the isolates to conventional antimicrobial agents, and the zoonotic risk of aggressions caused by bites and scratches from domestic cats.

[Trauma surgical relevance of bite injuries by animals and humans]

Bite injuries require differentiated treatment due to the deeply inoculated polymicrobial pathogen spectrum, possible concomitant injuries and pronounced soft tissue damage. Dog bites are the most common bite injuries but are less complicated to heal than human and cat bites. The location of the bite greatly depends on the age and the size of the bite victim as well as the type of bite perpetrator. In every case detection of the pathogen should be carried out to provide the best possible adapted treatment in the event of an exacerbation. The primary antibiotic treatment should be empirical with amoxicillin + clavulanic acid or ampicillin + sulbactam and, if necessary, adjusted according to the antibiogram. Depending on the findings, surgical treatment includes excision of the bite canal and a customized wound debridement. It is important to check the vaccination status of those involved and if indicated, to carry out postexposure prophylaxis for tetanus and rabies.

Early Intervention in Septic Arthritis of the Hand, Optimizing Patient Outcomes in Hand Infections-A Five-Year Retrospective Study

Background and Objectives: Hand septic arthritis is a potentially debilitating condition that can significantly affect patient functionality and quality of life. Understanding the demographic, clinical, and microbiological characteristics of this condition is crucial for its effective treatment and management. This study aimed to analyze the demographic and clinical profiles of patients with hand septic arthritis, to identify common microbial pathogens, and to evaluate the impact of various factors on clinical course and treatment outcomes. Material and Methods: This cross-sectional retrospective study examined patients diagnosed with septic arthritis of the hand, focusing on their demographic data, clinical presentation, causative organisms, treatment methods, and outcomes. Data on age, sex, cause of infection, affected sites, surgical interventions, microbiological findings, and patient outcomes were also collected. Results: This study found a higher prevalence of septic arthritis in males and identified bite as the predominant cause. Staphylococcus aureus is the most common pathogen. A large number of patients did not exhibit bacterial growth, and bacterial resistance did not significantly affect the outcome. Outcomes were statistically influenced by the timing of medical presentation and the presence of comorbidities. Conclusions: Early diagnosis and intervention are critical for effective management of hand septic arthritis. This study underscores the need for a comprehensive approach that considers patient demographic and clinical characteristics to optimize treatment outcomes. Awareness and preventive measures are essential to reduce the incidence and severity of this condition.

Performance and overview of clinically relevant areas of application of saliva testing in the cat

Introduction

The cat represents an important model in order to investigate basic physiological knowledge of salivary secretion as well as pharmacokinetics of active substances.

Objective

The aim of the study was to review in which diagnostic application areas saliva testing is routinely used and in which areas it could be further explored in the future.

Materials and methods

Literature relevant to the research question was collected in March 2022 using the Pubmed database.

Results

The diagnosis of infectious diseases in cat saliva is one of the most important fields of application. Saliva diagnostics may also indicate dental diseases, allergies or kidney and other metabolic diseases. Sexual and stress hormones can also be measured in cat saliva. A number of clinically relevant allergens in cat saliva that may cause allergies in humans has been investigated and described, in addition to infectious agents that can be transmitted from cats to humans.

Conclusions

Saliva testing in cats can be useful in many areas, including the detection of infectious diseases, allergies and dental disease. However, it is far from being used to its full potential within veterinary medicine.

Cat bite injuries to the hand and forearm: the impact of antibiotic treatment on microbiological findings and clinical outcome

INTRODUCTION

Patients and physicians often underestimate cat bite injuries. The deep and narrow wound seals quickly and provides an environment for the inoculated saliva and bacteria. Interestingly, the literature reports no bacterial growth in the microbiological workup of wound swaps in up to 43%. The time between bite injury and the first clinical presentation, the start of antibiotic treatment and surgical debridement might affect these findings. Therefore, the current project examines if (1) these factors impact the outcome of microbiological results following cat bite injuries and (2) the detection of bacterial growth leads to higher complication rates, longer hospital stays, longer total treatment time, or higher total treatment costs.

MATERIALS AND METHODS

This single-center retrospective study analyzed data from 102 adult patients. All patients received antibiotic and surgical treatment following a cat bite injury. Microbiological samples were collected during surgery in all cases. The time from the bite incident to the first presentation, beginning of antibiotic administration, and surgical debridement was calculated. Demographic data, complication rate, length of hospital stay, total treatment time, and total treatment costs were recorded. (1) A generalized linear model was fitted using the microbiological outcome as the dependent variable. (2) Two groups (negative or positive microbiological results) were formed and statistically compared.

RESULTS

The median age was 50 (SD 16), and 72% were female. (1) The time from the bite incident to the first clinical presentation, antibiotic administration, or surgical treatment was not associated with the outcome of the microbiological result. (2) No significant differences were observed between the two groups.

CONCLUSIONS

Our data do not suggest that early antibiotic administration or delayed surgical treatment affects the outcome of the microbiological workup following cat bite injuries to the hand and forearm. The microbiological outcome did not affect the complication rate, treatment time, and total treatment costs.

Audit of animal-related injuries at UK veterinary schools between 2009 and 2018

BACKGROUND

Animal-related injuries pose a significant risk to the veterinary profession. This study aimed to describe the incidence, demographics, context and consequences of animal-related injuries at UK veterinary schools.

METHODS

A multicentre audit of accident records (2009-2018) across five UK veterinary schools was performed. Injury rates were stratified by school, demographics and species. The context and cause of the injury were described. Multivariable logistic models explored factors associated with medical treatment, hospital visits and time off work.

RESULTS

An annual rate of 2.60 (95% confidence interval 2.48-2.72) injuries per 100 graduating students was calculated, varying between veterinary schools. Injuries were more frequently recorded in staff than students, and there were significant differences between staff and students in the activities performed preceding injury. Cats and dogs were associated with the highest number of reported injuries. However, injuries associated with cattle and horses were the most severe, with significantly higher hospital attendances and more time off work taken.

LIMITATIONS

Data were based on reported injuries and likely underestimate the true injury rate. The population at risk was hard to quantify as population size and exposure were variable.

CONCLUSION

Further research is recommended to explore the clinical and workplace management, including recording culture, of animal-related injuries among veterinary professionals.

Spatial patterns and risk of aggression of dogs and cats in a central township of Mexico City

Dog and cat aggressions are public health concerns associated with rabies transmission to the human population. The social and environmental conditions of marginalized and urban areas stand a risk due to people's contact with dogs. This study aimed to identify spatial patterns related to dog and cat aggression in a densely populated area in the center of Mexico City, analyzing the risk of aggression at the census unit level in the 2018-2020 triennium. This cross-sectional study was carried out in Coyoacán, in the south-central area of Mexico City's urbanized region. The total number of cases (n = 1,078) was obtained from monthly records of aggressions by dogs and cats, from the Control and Prevention of Zoonoses-Rabies Program of the Coyoacán Sanitary Jurisdiction. The information collected was related to the victims and the aggressors. Associations between the occurrence of bites and the characteristics of the victim were evaluated using a geographic information system (GIS), as well as the spatio-temporal distribution of the aggressions to the census unit level. Out of 1,078 cases reported, 977 (90.6%) were caused by dogs and 101 (9.4%) by cats, 55.1% (n = 587) occurred within the same household, and 13.7% (n = 148) were categorized as severe injuries. Adult men were the most affected group. Attacks on the street had a higher risk of resulting in a severe injury, compared to those that occurred at home (OR 1.63, 95CI 1.15 - 2.31, p <0.006). According to the standardized rate of the triennium, the values ​​ranged between 54.1 and 619 aggressions per 100,000 inhabitants, and summer was the season with a higher probability of occurrence. These results provide a basis for the analytical investigation of the spatial patterns of dog and cat aggression, highlighting the need to implement efficient surveillance systems and public health strategies.

Polymer-Based Constructs for Flexor Tendon Repair: A Review

A flexor tendon injury is acquired fast and is common for athletes, construction workers, and military personnel among others, treated in the emergency department. However, the healing of injured flexor tendons is stretched over a long period of up to 12 weeks, therefore, remaining a significant clinical problem. Postoperative complications, arising after traditional tendon repair strategies, include adhesion and tendon scar tissue formation, insufficient mechanical strength for early active mobilization, and infections. Various researchers have tried to develop innovative strategies for developing a polymer-based construct that minimalizes these postoperative complications, yet none are routinely used in clinical practice. Understanding the role such constructs play in tendon repair should enable a more targeted approach. This review mainly describes the polymer-based constructs that show promising results in solving these complications, in the hope that one day these will be used as a routine practice in flexor tendon repair, increasing the well-being of the patients. In addition, the review also focuses on the incorporation of active compounds in these constructs, to provide an enhanced healing environment for the flexor tendon.

Biting the hand that feeds you: Management of human and animal bites

Bites from animal and humans represent a very small proportion of all the patients presenting to emergency departments, However, they require prompt medical and surgical intervention in order to minimise the risk of infection, that may lead to limb and life-threatening complications. In this review article we synthesise the existing literature for treatment of human and animal bites and offer practical considerations when managing bite injuries.

Management of neglected vicious cat bite in a child: A case report

Cat bites make up 10% of all animal bites and have a high incidence of infection. Cat bites can cause severe deep bacterial infection in closed spaces such as tendon sheath, joints, and bones due to their sharp teeth. Generally, cat bite wound infections are reported at 30%-60%, which is double compared to rat or dog bites. However, cat bites are easily misjudged due to their minimal appearance of tissue injury. Case Report:We hereby present a case of a neglected cat bite wound complicated with infection in a healthy child. The wound was debrided in the operation theatre, and a ten-day course of antibiotics was completed. No further infection was noted and the child was discharged home well. Conclusion: There is no exact algorithm of treatment for cat bites. However, cat bites are nasty wounds that should be treated early and aggressively. Empirical oral or intravenous antibiotics should be started immediately, and adequate surgical debridement is indicated to provide a better outcome as there are no standardized protocols for initial management.

Treatment of hand infections using WALANT -when the anesthesiologist is not available: A retrospective cohort study

Backround

The aim of this study was to determine, if Wide Awake Local Anesthesia No Tourniquet (WALANT) can be used as an alternative method of providing anesthesia in management of deep infections of the hand. Since the advent of WALANT in 2003, infections of the hand have been regarded as a contraindication to its use. Occasional shortage of anesthesiologic manpower, especially during busy call hours and the current COVID-19 pandemic can lead to delay of treatment where urgent surgery is needed, to prevent progress of an infection, that can result in severe morbidity.

Methods

In the period from 2015 to 2020, 16 patients with various infections of the hand underwent 17 operations using WALANT in a Hand Trauma and Replantation Center (HTRC) in Germany. Retrospective cohort analysis of their operation reports, with emphasis on location of infection, time and duration of the operation, intraoperative incidents and complications were carried out. We also evaluated the need for revision surgery or necessity to convert to general anesthesia and factors causing delay till the time of surgery.

Results

No case of inadequate analgesia, the need to convert to general anesthesia, ischemic events or cardiovascular complications with the use of the WALANT solution containing adrenaline and lidocaine in the treatment of deep tissue infections.

The highest priority of limb preservation was ensured as no patient progressed to amputation of a digit or the hand. There was a statistically significant difference (p≤0.01) in delay from the time of admission until surgery of up to 9h24 m (SD±3h34 m) during the week and 4h10 m (SD±2h28 m) during the weekend.

Conclusion

The status of infection as an absolute contraindication to the use of WALANT should be revised. Especially when human resources are limited, WALANT is an adequate technique to enable quick anesthesia for urgent treatment to prevent progression of hand infections.

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Wide Awake Local Anesthesia No Tourniquet can be used to treat deep hand infections.

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In the COVID-19 pandemic alternative ways of providing anesthesia are needed.

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Absolute contraindication to the use of WALANT should be reevaluated.

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“time is function”, urgent treatment remains key in management of hand infections.

Practical Review of the Management of Animal Bites

Animal bites are common worldwide. Due to the plethora of animals, there are diverse pathogens with specific associated risks and treatment algorithms. It is crucial to understand these to develop and execute appropriate management plans. This practical review was designed to amalgamate the most common bites worldwide and synthesize data to help guide treatment plans.

METHODS

A PubMed literature search was performed focusing on the major animal bites. High-level studies were preferred and analyzed but lower-level studies were also used if high-level studies did not exist.

RESULTS

The tables presented in this article cover the pertinent information regarding the incidence, common presentation, initial treatment, and potential complications associated with bites from dogs, cats, horses, rodents, snakes, marine life, and spiders. Many of the pathogens associated with the bites are treatable with various and somewhat common antimicrobials, though some are less easy to access. Basic irrigation, debridement, and wound culture are common to almost every animal and should be the first step in treatment.

CONCLUSIONS

Based on the current studies, the most important factor in treating animal bites is timely presentation to a medical facility and/or physician. It is critical that the offending animal be accurately identified to help guide medical and surgical algorithms, including specific antimicrobial treatment guided by the most commonly presenting pathogens specific to certain animals.

[Osteitis/Osteomyelitis of the Hand and Wrist]

Osteomyelitis of the hand and wrist is uncommon compared to the infections of the long bones but not rare. There is poor evidence on many answers to questions concerning this disease. This includes careful consideration of the prevalence, pathogenesis, microbiology, diagnostic methods and the conservative, medical and surgical treatment. The emergence of the disease can subdivided in post-traumatic, postoperative, spread from contiguous infections and hematogenous. The individual patient-specific risk must be considered. Early diagnosis and correct management are essential to preserve bony structures and the articular function of the hand. A two-step surgical procedure is usually necessary, but uncertainties about the optimal treatment are still existing. Satisfactory control rates of the infection and successful bone reconstructions can be achieved. But complications, a limited range of motion and amputations of finger parts can still not be avoided in all cases.

Infections of Deep Hand and Wrist Compartments

The human hand is the most exposed part of the body to highest risk for injuries, loss of the skin integrity, and to the inoculation of bacteria, most commonly Staphylococcus aureus, Streptococcus β-haemolytic, and gram-negative. In case of an infection, the mobile anatomical structures and the synovial membranes in close proximity to each other may spread the pus towards deep spaces and compartments. Mild early infections without an abscess formation may respond to antibiotics, but at more advanced stage, erythema, swelling, stiffness, and severe pain may ensue. Abscess formation will cause debilitating pain, fever, systemic symptoms, and even sepsis. Necrotizing infections may threaten not only the limb, but also patient’s life. Therefore, an initially “trivial” hand injury should never be neglected, as it might turn into a deep space infection, which must be treated immediately with drainage, wound debridement, and i.v. antibiotics. Delay in diagnosis and inadequate initial management might rapidly lead to abscess formation, destruction of the gliding surfaces and the normal anatomy, and irreparable functional deterioration.

Risk factors for reoperation in primary hand infections: a multivariate analysis

INTRODUCTION

Severe hand infection might cause severe morbidity including stiffness, contracture and possibly amputation. The purpose of this study was to analyse the current epidemiology of adult acute hand infections in a European Hand Surgery Centre and to identify risk factors for secondary surgery.

MATERIALS AND METHODS

We retrospectively analyzed a cohort of 369 consecutive patients with primary infection of the hand that were admitted to our department and required operative treatment. The following variables were recorded: demographics, medical history, cause and location of infection, laboratory values, cultured microorganisms and reoperation rate. Univariate logistical regression was used to identify variables associated with reoperation and backward selection was applied to identify the final multiple variable model.

RESULTS

The mean age at the time of operation was 50.5 years (SD 16.1, range 19-91) and 65.6% of patients were male. Sharp cuts or lacerations were the most common cause (29.0%) for hand infections. 81 different species were cultivated and in 47 patients (12.7%), the cultures were positive for more than one organism. Staphylococcus aureus was the most common cultured organism (19.5%). There were relatively few cases of methicillin-resistant Staphylococcus aureus (2.2%). 80 patients (21.7%) needed more than one operation. We identified three risk factors for reoperation in a multivariate analysis: an elevated value of C-reactive protein at the time of admission, involvement of multiple sites and bacterial growth in culture.

CONCLUSION

The rate of infections with MRSA in this European cohort was lower compared to reports from the USA. Thus, hand surgeons should choose their empiric antibiotic therapy depending on their patient population. The knowledge of risk factors for severe hand infections might help surgeons to identify patients at risk for additional surgery early.