Household Pets and Human Infections

Selected Zoonoses

Human risks of acquiring a zoonotic disease from animals used in biomedical research have declined over the last decade because higher quality research animals have defined microbiologic profiles. Even with diminished risks, the potential for exposure to infectious agents still exists, especially from larger species such as nonhuman primates, which may be obtained from the wild, and from livestock, dogs, ferrets, and cats, which are generally not raised in barrier facilities and are not subject to the intensive health monitoring performed routinely on laboratory rodents and rabbits. Additionally, when laboratory animals are used as models for infectious disease studies, exposure to microbial pathogens presents a threat to human health. Also, with the recognition of emerging diseases, some of which are zoonotic, constant vigilance and surveillance of laboratory animals for zoonotic diseases are still required.

Acute renal failure: a common manifestation of leptospirosis

Leptospirosis is an infectious disease caused by pathogenic leptospires and may vary in degree from an asymptomatic infection to severe and fatal illness. Sixteen patients (all males; aged 40+/-17 years) with leptospirosis were admitted to Sişli Etfal Training and Research Hospital between July 1998 and August 2003 and were retrospectively reviewed. Age, gender, occupation, clinical presentation, laboratory features, seasonal distribution of the disease, diagnostical approach, and prognostic factors were evaluated. Eleven patients were cured with no complication; four patients died of hepatic and/or renal failure. Eight patients presented with acute renal failure; seven of them needed dialytic support. One patient developed chronic renal failure and had to undergo regular hemodialysis. All deceased patients (aged 61+/-7 years) were anuric at admission and their serum bilirubin changed between 39-44 mg/dL (mean 41.3+/-2.2 mg/dL). Cured patients ranged in age from 14-62 years (34+/-14 years) and their serum bilirubin levels ranged from 9-35 mg/dL (23.1+/-11.4 mg/dL). Crystalline penicillin G 12 million U/day was administered to all patients. Six patients also received hepatic coma treatment. This study emphasizes that leptospirosis presenting with renal failure is a severe disease, and mortality is frequently related to delays in diagnosis due to lack of clinical understanding. The association of acute renal failure and jaundice should lead the clinician to suspect leptospirosis. We concluded that old age, oliguria/anuria, high serum bilirubin levels (>36 mg/dL), and high serum potassium levels might be risk factors that increase mortality in leptospirosis.

Isolation of a fastidious Bergeyella species associated with cellulitis after a cat bite and a phylogenetic comparison with Bergeyella zoohelcum strains

Bergeyella zoohelcum is an uncommon zoonotic pathogen typically associated with cat or dog bites. Previously, only five cases of B. zoohelcum infection have been reported. We report the isolation and characterization of a fastidious Bergeyella species from acute cellulitis in the upper extremity of a 60-year-old woman. The organism was too fastidious for identification and susceptibility testing with traditional culture methods. The isolate was characterized further by PCR amplification and sequencing of the 16S rRNA gene with broad-range eubacterial primers. Phylogenetic analysis of the 16S ribosomal DNA sequence indicated that this isolate was a member of the species B. zoohelcum (previously Weeksella zoohelcum), a gram-negative bacillus that is rarely associated with infections in humans. Despite sharing a close genetic relationship with other B. zoohelcum strains, this isolate was extremely fastidious in nature, raising the possibility that similar strains from cat or dog bite wound infections have been underreported.

Leptospirosis presenting as diffuse alveolar hemorrhage: case report and literature review

The literature on diffuse alveolar hemorrhage heavily emphasizes the causal role of vasculitides. We present a patient with diffuse alveolar hemorrhage caused by leptospirosis. Although the pathology in leptospirosis occurs secondary to a vasculitic process, this disease is not listed as a cause of diffuse alveolar hemorrhage in the review literature. In the right clinical scenario, the disease should be considered in a patient presenting with diffuse alveolar hemorrhage.

Zoonotic infections from pets. Understanding the risks and treatment

As much as we hate to admit it, even the gentlest of our friendly pets can harbor harmful pathogens, and although the fact is not widely known, pet-associated infections can significantly affect the health of humans. In this article, Dr Morrison focuses on pets and their accompanying potential zoonoses, outlining how these diseases can be transmitted to humans and how the infections are treated. Special attention is paid to rabies and toxoplasmosis, which have attained particular notoriety over time.

Leptospirosis in Latin America

Leptospirosis is a common disease in Latin America. Transmission to humans occurs by contact with water or soil contaminated with the urine of rodents, dogs, or livestock. Pathogenesis is still poorly understood, and bacterial toxin or virulence factors are probably responsible for many features of the disease. The anicteric form is the most frequent presentation, and its clinical picture resembles influenza or other acute febrile diseases. Icterohemorrhagic leptospirosis, or Weil's syndrome, represents the severe form of the disease. Its clinical picture is similar to bacterial sepsis and multiple organ involvement occurs, mainly in kidneys and lungs, and causes great morbidity and mortality. Death is often related to multiple organ failure and pulmonary hemorrhages. Diagnosis is based on serology or blood, cerebrospinal fluid and urine cultures in specific media. Treatment involves a combination of antibiotics and supportive measures.

[Infections associated with pets]

INTRODUCTION

Domestic pets can transmit numerous infections, including bacterial, parasitic, fungal, and viral diseases. This paper reports the epidemiologic, clinical, therapeutic and prophylactic data of these zoonoses.

CURRENT KNOWLEDGE AND KEY POINTS

The routes of transmission are various. Bites and scratches are the most common health hazards and result in localized infections. Pasteurellosis, various aerobic and anaerobic infections, and cat-scratch disease are predominant. Bites are treated by cleaning the wound, rabies and tetanus prophylaxis, and the appropriate use of antibiotics. Other infections are transmitted through cutaneous, mucous, digestive or respiratory routes, by direct contact with the pets, excreta, or by arthropods. The most common are gastrointestinal (campylobacter, salmonella, yersinia, parasites, etc), dermatologic (dermatophytoses, scabies, cutaneous larva migraines, etc.), respiratory (psittacosis, etc.), and multisystemic (toxoplasmosis, toxocariasis, leishmaniosis). Certain people are at high risk for diverse diseases: small children (toxocariasis, helminthiasis), pregnant women (toxoplasmosis), and immunodeficient patients (cryptosporidiosis, salmonellosis, systemic pasteurellosis). These infectious diseases can be partly prevented by avoiding contact with diseased animals, and by washing the hands following exposure to pets or pet-derived excreta. Specific vaccines for humans and pets, as well as worming pets regularly, form an important part of the prevention. Veterinarians must discourage the keeping of wild or exotic animals as pets.

FUTURE PROSPECTS AND PROJECTS

National health survey institutions and new communication systems can improve our knowledge about the real epidemiology of pet-transmitted zoonoses.

Prevention of infection in the immunocompromised host

The Association for Professionals in Infection Control and Epidemiology, Inc, is accredited as a provider of continuing education in nursing by the American Nurses Credentialing Center's Commission on Accreditation. This learner-paced study package is designated for 1.1 contact hours. APIC's California nursing provider number is CEP 7146. This continuing medical laboratory education activity is recognized by the American Society of Clinical Pathologists as meeting the criteria for 1 CMLE credit hour. ASCP CMLE credit hours are acceptable to meet the continuing education requirements for the ASCP Board of Registry Continuing Competence Recognition Program. (See the instructions and examination at the end of the article.)Infectious diseases represent a major cause of morbidity and mortality in immunocompromised patients. Infectious complications are often predictable and may be preventable. This article is an overview of practical considerations in the care of immunocompromised patients. Recognizing the compromised host, identifying and correcting risk factors in advance, and reducing sources of infection all play a role in prevention. Topics were chosen to include the areas of care that differ from the immune competent patient, such as diet, pet therapy, handwashing, immunizations, augmentation of host resistance, prevention of pneumonia, and antibiotic prophylaxis. National practice guidelines are cited when possible; evidence-based literature review and experience are applied to situations lacking consensus statements. Treatment decisions are made in areas for which information is often incomplete. A systematic approach to care of the immunocompromised host, tailored to the individual patient's needs, should reduce the risk of infection.