Rat Bite Fever: Variability in Clinical Presentation and Management in Children.

Rat bite fever is a systemic illness most commonly caused by Streptobacillus moniliformis that is classically characterized by fever, rash and migratory polyarthritis. Here, we highlight the highly variable clinical presentations of rat bite fever in children and the importance of maintaining a high degree of suspicion so appropriate treatment can be promptly initiated.

Rat bite fever caused by Streptobacillus moniliformis infection in a Chinese patient.

BACKGROUND: Rat bite fever (RBF), a severe infectious disease, can result from transmission of the pathogen Streptobacillus moniliformis (S. moniliformis) by rat bite. RBF diagnosis can be overlooked. CASE PRESENTATION: We present a case of RBF in a Chinese patient who was infected with S. moniliformis in mainland China. Meta-next generation sequencing (mNGS) was used to identify potential pathogens and detected S. moniliformis genome sequences in the pustular sample in less than 72 h. Then the diagnosis was validated by polymerase chain reaction analysis. Despite having severe RBF with complications, this 54-year-old male patient was successfully cured with penicillin as a result of timely pathogen-based diagnosis. CONCLUSIONS: Physicians should inquire about recent rat exposure and consider the possibility of RBF when a patient develops unexplained fever and rashes. mNGS is a new diagnostic technology and may identify RBF pathogens even when blood culture results are negative.

Streptobacillus moniliformis bacteremia in a rheumatoid arthritis patient without a rat bite: a case report.

BACKGROUND: Rat bite fever is a relatively rare infectious disease due to infection with Streptobacillus moniliformis or Spirillum minus mainly via directs bite by rats, mice, or other rodents. If there is no clear bite history, the diagnosis is difficult or may not be made. CASE PRESENTATION: A 72-year-old Asian female with rheumatoid arthritis was admitted for high grade fever and walking difficulty with severe lumbago. Initially, we suspected lumber compression fracture with deterioration of rheumatoid arthritis, but Gram-negative bacilli were isolated from blood culture during hospitalization. The isolated organism was identified as S. moniliformis by 16S ribosomal ribonucleic acid (rRNA) sequencing. S. moniliformis is well known to be a primary causative organism of rat bite fever, but this patient had no history of rat bite. Had S. moniliformis bacteremia not been detected, she might have been treated for rheumatic exacerbation. CONCLUSION: We emphasize the importance of performing appropriate microbial culture testing for identifying potential infectious diseases. We also conclude that S. moniliformis infection can become established with contaminated vehicle contact alone, not only as a direct result of a bite. We must keep mind that those working in places where rodents breed or are at risk of contact with rats or mice might be at risk for contracting this unusual disease.

A case of septic arthritis from rat-bite fever in Hawai'i.

BACKGROUND: Infection associated with a rat bite has been known for centuries. Streptobacillus moniliformis is a zoonotic organism identified in the 20th century as the causative agent of most cases of rat bite fever outside of mainland Asia. There are no previously published cases of this pathogen in Hawai'i. CASE PRESENTATION: The authors present a case of Streptobacillus moniliformis causing septic polyarthritis in a 59-year-old Hawaiian man with a history of alcohol abuse and recurrent exposure to rodents in his apartment. Blood cultures from the patient were negative. The organism was isolated after three days only in thioglycolate broth from a synovial fluid culture. 16S rRNA sequencing of extracted and purified DNA confirmed the organism as Streptobacillus moniliformis. CONCLUSION: Diagnosis of infection from Streptobacillus moniliformis is difficult to make because of the fastidious nature of the organism's growth, as well as inhibitors present in standard blood culture bottles. The use of bacterial 16S rRNA sequencing may aid in an earlier diagnosis for this disease. More research is required to identify host and virulence risk factors for involvement of specific organ systems.

Rat bite fever and Streptobacillus moniliformis.

Rat bite fever, caused by Streptobacillus moniliformis, is a systemic illness classically characterized by fever, rigors, and polyarthralgias. If left untreated, it carries a mortality rate of 10%. Unfortunately, its nonspecific initial presentation combined with difficulties in culturing its causative organism produces a significant risk of delay or failure in diagnosis. The increasing popularity of rats and other rodents as pets, together with the risk of invasive or fatal disease, demands increased attention to rat bite fever as a potential diagnosis. The clinical and biological features of rat bite fever and Streptobacillus moniliformis are reviewed, providing some distinguishing features to assist the clinician and microbiologist in diagnosis.

Haverhill fever with spine involvement.

Haverhill fever and rat-bite fever are closely-related syndromes caused by Streptobacillus moniliformis. This infection is characterized by the abrupt onset of fever with rigors, myalgias, headache, polyarthritis, and rash. We report a case of infection with S. moniliformis that manifested as acute polyarthritis with involvement of the spine. To our knowledge, involvement of the spine has not been reported previously with this infection. Diagnosis can be particularly difficult in the absence of fever or obvious exposure to rodents, as in our case. A high degree of awareness is necessary to make the diagnosis of this potentially fatal infection, which is easily treatable.

[Digital purpura revealing septicaemical rat-bite fever]. / Purpura digital isolé révélant une streptobacillose septicémique après morsure de rat.

INTRODUCTION: Infection with Streptobacillus moniliformis is an uncommon illness which can lead to death if untreated. We report the case in which initially cutaneous signs permitted diagnosis and further identification of the organism. CASE REPORT: A 42 year-old woman presented with a three-day history of acrally distributed purpuric macules on her fingers. Two days later, she was admitted for arthritis of the knees and wrists. There were two large pustules on the left elbow and the right knee. Laboratory studies showed inflammatory changes. The diagnosis of streptobacillary rat-bite fever was made after isolation of Gram-negative bacilli from a blood-culture and from cutaneous lesions. Finally identification of the organism was made by molecular biology analysis. The patient received intravenous ofloxacin and imipenem with complete resolution of arthritis and the cutaneous lesions. DISCUSSION: Streptobacillary rat-bite fever is a systemic infectious disease. It is caused by Streptobacillus moniliformis, organism found in the oropharyngeal flora of small rodents, especially rats. The illness is uncommon in urban settings. It starts by fever, followed by arthritis and rash. Septicaemical rat-bite fever may start only with cutaneous involvement such as acral purpura, like in our case. This clinical manifestation must be recognized by the dermatologist, because the illness can lead to death if untreated.

Streptobacillus moniliformis endocarditis in an HIV-positive patient.

Streptobacillus moniliformis is the causative agent of rat bite fever, with endocarditis being a rare but well-documented complication. We report the case of an HIV-positive man who acquired S. moniliformis endocarditis through a rat bite. No predisposing cardiac lesion was known. He was treated with ceftriaxone 2 g/day i.v. for 3 weeks, gentamicin 120 mg/day i.v. for 2 weeks and penicillin 24x10(6) units/day for 1 week. At the end of the antibiotic therapy he suffered a generalized Candida albicans infection, which was treated with fluconazole for 1 week. He was subsequently discharged in a satisfactory condition.

Gatos y ratas: rasguños y mordeduras / Cats and rats: scratches and bites

Numerosas afecciones son transmitidas al hombre por diferentes vectores, sean éstos insectos, pájaros o mamíferos. Entre las transmitidas por estos últimos, en la presente revisión se abordaron: la enfermedad por mordedura de rata que es básicamente un cuadro febril agudo, intenso, de comienzo brusco y de evolución recurrente y la enfermedad por rasguño de gato que se manifiesta por adenopatías sin signos inflamatorios locales, de lenta evolución regresiva y con escasa repercusión sobre el estado general. Ambas afecciones son más comunes en nuestro medio de lo que habitualmente se piensa y responden favorablemente a diversos antibióticos pero inicialmente plantean, con frecuencia, problemas de diagnóstico diferencial con enfermedades de pronóstico más grave

Streptobacillus moniliformis--a zoonotic pathogen. Taxonomic considerations, host species, diagnosis, therapy, geographical distribution.

Streptobacillus moniliformis (Sm), the causative agent of rat-bite fever and Haverhill fever in man, is also a pathogen in certain laboratory and domestic animals. With the introduction of modern maintenance systems, this microorganism seemed to be eradicated from laboratory animal units, but recent reports of Streptobacillus moniliformis (Sm) in colonies of laboratory rodents give evidence that this 'forgotten' bacterium can still be found even behind hygienic barrier systems. Although various national and international recommendations on microbiological screening include Sm, attempts to screen might fail because of insufficient knowledge about this remarkable bacterium. This article highlights these problems. As there is no recent review of Streptobacillus moniliformis, present knowledge of this zoonotic agent is summarized to include: description of the bacterium, its taxonomic position, host spectrum and clinical importance for animals and man, cultivation, diagnosis, antibiotic therapy, risk to laboratory personnel (occupational hazard) and geographical distribution.

Streptobacillus moniliformis epizootic in barrier-maintained C57BL/6J mice and susceptibility to infection of different strains of mice.

We report a Streptobacillus moniliformis epizootic in barrier-maintained SPF mice. Although various inbred and F1 hybrid strains of mice have been kept in this animal facility, only C57BL/6J Han [corrected] mice showed clinical signs of disease. During the course of the epizootic, 825 breeding animals (approximately 36% of the breeders) died or had to be killed because of severe clinical signs. Although sequential treatment with ampicillin and chlortetracycline gave good therapeutic results, the animal facility was vacated in order to exclude any risk of cross-contamination of the other rodent colonies in our institute. The source and route of transmission of S. moniliformis could not be elucidated. To investigate strain dependent differences experimental infection of different strains of mice with our S. moniliformis isolate was performed. After oral infection only C57BL/6J showed the typical signs of a cervical lymphadenitis and gave an immunological response. BALB/cJ, C3H/He, DBA/2J, CB6F1 and B6D2F1 mice were not affected except in two cases of DBA/2J and B6D2F1 mice where seroconversion was observed. After intravenous infection of C57BL/6J, DBA/2J [corrected] and BALB/cJ all animals showed positive titers in the indirect immunofluorescence test (IIF). One hundred percent of the C57BL/6J, forty percent of the DBA/2J, and none of the BALB/cJ mice developed severe symptoms. The results demonstrate that the susceptibility to streptobacillosis is predominantly influenced by genetic factors.

Streptobacillus actinoides (Bacillus actinoides): isolation from pneumonic lungs of calves and pathogenicity studies in gnotobiotic calves.

Pneumonic lungs of 56 calves were examined and 12 (21 per cent) of them yielded Streptobacillus moniliformis-like organisms. These organisms resembled those previously described as Bacillus actinoides or Actinobacillus actinoides. After intratracheal inoculation of cultures of two strains of these organisms, pneumonic consolidation developed in five out of six gnotobiotic calves and involved up to 16 per cent of the lung surface. Histological lesions of interstitial pneumonia were observed in the lungs of all six calves. Swellings at the site of the infection followed intradermal and subcutaneous inoculation of cultures of all strains in calves. Mice showed no signs of illness following intraperitoneal injection of three stains. The bacteriological findings suggested that a more appropriate name for these organisms would be Streptobacillus actinoides.

Host-parasite relationships in experimental Streptobacillus moniliformis arthritis in mice.

Several variables of host and parasite, relating to the establishment of the chronic Streptobacillus moniliformis-induced arthritis, were studied. Results from these studies indicated (i) that intravenous inoculation of the organism produced a progressive bacteremia and a polyarthritis, whereas subcutaneous inoculation into the top of the back foot produced an intermittent bacteremia and arthritis only in that foot, (ii) that serum-broth-grown cells were more virulent than serum-agar-grown cells, (iii) that young animals were more susceptible to infection than old, and (iv) that the organism apparently had a predilection for joints. It was also determined that the leukocyte and antibody responses of mice to infection were minimal with a slight neutrophilia and a maximum antibody titer of 1:640 detected after infection. Measurements of the effectiveness of antibody and leukocytes in prevention or resolution of infection indicated (i) that the presence of homologous antibody prior to infection prolonged the incubation period for development of the lesion, (ii) that the opsonic index was 1.2 to 1.4, and (iii) that the organism was apparently resistant to destruction by in vitro phagocytosis and actually increased in number in the presence of phagocytes. It was concluded that these represented some of the prime factors contributing to the establishment of the infection and its chronicity.