Fatal Streptobacillus moniliformis Infection in a Two-Month-Old Infant

Abstract

Streptobacillus moniliformis is an uncommon human pathogen contracted from exposure to rodents. It usually produces a mild, protracted illness (rat-bite fever, Haverhill fever, erythema arthriticum epidemicum) that has either a favorable response to antibiotic therapy or spontaneously resolves. This report describes a fatal case of Streptobacillus moniliformis in an infant bitten by a wild rat. The autopsy findings included an interstitial pneumonia, fibrinous endocarditis, mild mononuclear meningitis, hepatosplenomegaly and lymphadenopathy, erythrophagocytosis, and sinusoidal mononuclear cell infiltrates in regional lymph nodes and the liver. To the authors' knowledge, this is the first report of the autopsy pathology findings of this agent.

Rat Bite Fever andStreptobacillus moniliformis

“…S. moniliformis exists in two variant types, the normally occurring bacillary form and the inducible or spontaneously occurring, cell wall-deficient L form, growing with a "fried-egg" colony morphology. The L form is considered nonpathogenic (28); spontaneous conversion between the two forms in vitro has been reported and is felt by some to be responsible for clinical relapses and resistance to therapy (72).…”

“…However, the organism appears to be capable of producing morphological findings not customarily associated with bacterial infections. Autopsy of rat bite fever victims demonstrates pronounced erythrophagocytosis, hepatosplenomegaly, interstitial pneumonia, and lymph node sinus hyperplasia (72). Endocarditis and myocarditis have also been demonstrated, along with degenerative changes in the kidneys and liver (1).…”

“…Over 200 cases of rat bite fever have been documented in this country, but this represents a significant underestimate because neither the disease nor its causative organism is reportable to health departments. The youngest reported case of rat bite fever was in a 2-month-old infant (72), and the oldest reported case occurred in an 87-year-old man (82). The risk of infection after a rat bite appears to be 10% (23,35), and the mortality rate of untreated rat bite fever is approximately 13% (65,91).…”

Selected Zoonoses

“…Most cases of RBF resolve spontaneously within 14 days; however, 13% of untreated cases are fatal (Sens et al, 1989). Prophylactic efficacy of antibiotic treatment following rat bites has not been thoroughly investigated.…”

Rattenbißfieber Infektion mit Streptobacillus moniliformis

“…Fallbeispiels [5] nach einer Bißverletzung akut mit Bauchschmerzen, hohem Fieber, zunehmendem Exanthem und Arthritis erkrankte, zeigte unser 2. Komplikationen wie Endokarditiden [8,23,30], Pneumonien und Abszedierungen in subkutanes Gewebe, Gehirn und Herzmuskel [28] bedingen hierbei eine relativ hohe Letalitä t von bis zu 13 % [14,24,32]. Insbesondere dieser Verlauf weist auf die Gefä hrlichkeit der Erkrankung hin.…”