Cowpox Virus Outbreak in Banded Mongooses (Mungos mungo) and Jaguarundis (Herpailurus yagouaroundi) with a Time-Delayed Infection to Humans

BACKGROUND:Often described as an extremely rare zoonosis, cowpox virus (CPXV) infections are on the increase in Germany. CPXV is rodent-borne with a broad host range and contains the largest and most complete genome of all poxviruses, including parts with high homology to variola virus (smallpox). So far, most CPXV cases have occurred individually in unvaccinated animals and humans and were caused by genetically distinguishable virus strains. METHODOLOGY/PRINCIPAL FINDINGS:Generalized CPXV infections in banded mongooses (Mungos mungo) and jaguarundis (Herpailurus yagouaroundi) at a Zoological Garden were observed with a prevalence of the affected animal group of 100% and a mortality of 30%. A subsequent serological investigation of other exotic animal species provided evidence of subclinical cases before the onset of the outbreak. Moreover, a time-delayed human cowpox virus infection caused by the identical virus strain occurred in a different geographical area indicating that handling/feeding food rats might be the common source of infection. CONCLUSIONS/SIGNIFICANCE:Reports on the increased zoonotic transmission of orthopoxviruses have renewed interest in understanding interactions between these viruses and their hosts. The list of animals known to be susceptible to CPXV is still growing. Thus, the likely existence of unknown CPXV hosts and their distribution may present a risk for other exotic animals but also for the general public, as was shown in this outbreak. Animal breeders and suppliers of food rats represent potential multipliers and distributors of CPXV, in the context of increasingly pan-European trading. Taking the cessation of vaccination against smallpox into account, this situation contributes to the increased incidence of CPXV infections in man, particularly in younger age groups, with more complicated courses of clinical infections

CPXV infected exotic animals (except <i>Muroidae</i>).

<p>nk: not known.</p

Lesions on mongooses #1 and #8.

<p>(A) Acute lesions on the head of mongoose #1 with a generalized infection and (B) subacute to chronic epidermal lesions with scarring on the body of mongoose #8.</p

Severe cowpox lesion on the patient's chin caused by the identical virus strain that was isolated from deceased mongooses and jaguarundis.

<p>Severe cowpox lesion on the patient's chin caused by the identical virus strain that was isolated from deceased mongooses and jaguarundis.</p

Orthopoxvirus-specific antibody titers, measured by IFAT, in animals at Zoo Krefeld, Germany, before and after intramuscular vaccination with modified VACV Ankara (MVA).

<p>Date of sera sampling: ¹24 May 2007, ²12 Dec 2007, ³30 Jan 2008, ⁴29 Jun 2007, ⁵14 Mar 2007.</p><p>Date of first vaccination: ⁶03/05–25/08.</p><p>Date of second vaccination: ⁷11 Apr 2008–7 May 2008.</p><p>Secondary antibodies: ⁸α-feline, ⁹Protein A/G, ¹⁰α-canine, ¹¹Protein A.</p><p>IFAT: Indirect fluorescence antibody test detecting specific anti-orthopoxvirus antibodies, the reciprocal titer is given.</p><p>n.d.  =  not done.</p

Histopathological and electron microscopical examination.

<p>(A) Multiple circumscribed, elevated, pale red, plaque-like foci in the lung of mongoose #1, (B) HE-stained skin lesion of mongoose #1 showing multiple eosinophilic intracytoplasmic inclusion bodies (arrows) and mild ballooning degeneration of epidermal cells associated with focal severe necrotizing dermatitis with neutrophilic and lymphoplasmacellular infiltrates, (C) HE-stained liver section of mongoose #1 showing severe necrosis with hemorrhage and mild inflammatory infiltration and degenerating hepatocytes with multiple intracytoplasmic inclusion bodies (arrow), (D) HE-stained lung section of mongoose #1 showing a bronchiolus with markedly hyperplastic epithelium and focal obliterating proliferation undergoing necrosis. Negative-stain electron microscopy revealing typical orthopoxvirus-like particles in skin lesion material of mongoose #1 (E) and jaguarundi #1 (F).</p

Characteristics of cowpox virus isolates and orthopoxvirus reference strains.

<p>CPXV: cowpox virus, VACV: vaccinia virus, CMLV: camelpox virus, MPXV: monkeypox virus, ECTV: ectromelia virus, VARV: variola virus.</p><p>nk: not known.</p

Clinical and laboratory findings in a cowpox virus outbreak affecting a colony of 13 banded mongooses (<i>Mungos mungo</i>) and 2 jaguarundis (<i>Herppailurus yagouaroundi</i>) at Krefeld Zoo, Germany. Skin, lung, liver, tongue, spleen and feces were tested by real-time PCR; blood by IFAT.

<p>Positive virus isolates:</p>1<p>CPXV MonKre08/1,</p>2<p>CPXV MonKre08/2,</p>3<p>CPXV MonKre08/3,</p>4<p>CPXV JagKre08/1,</p>5<p>Sera were collected on the day of death,</p>6<p>Sera and skin scrapings collected on 20 Feb 2008,</p>7<p>J#2 also PCR positive for lymph nodes, larynx and colon,</p>8<p>Poxvirus infection verified by histology,</p><p>M: mongoose, J: jaguarondi.</p><p>IFAT: Indirect fluorescence antibody test detecting specific anti-orthopoxvirus antibodies with protein G (mongoose) or α-feline (jaguarundi) as secondary antibodies, the reciprocal titer is given.</p