Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus.

Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV.

Phylogenetic and ecologic perspectives of a monkeypox outbreak, southern Sudan, 2005.

Identification of human monkeypox cases during 2005 in southern Sudan (now South Sudan) raised several questions about the natural history of monkeypox virus (MPXV) in Africa. The outbreak area, characterized by seasonally dry riverine grasslands, is not identified as environmentally suitable for MPXV transmission. We examined possible origins of this outbreak by performing phylogenetic analysis of genome sequences of MPXV isolates from the outbreak in Sudan and from differing localities.

An Investigation of a Cluster of Parapoxvirus Cases in Missouri, Feb-May 2006: Epidemiologic, Clinical and Molecular Aspects.

In the spring of 2006, four human cases of parapoxvirus infections in Missouri residents were reported to the Centers for Disease Control and Prevention (CDC), two of which were initially diagnosed as cutaneous anthrax. This investigation was conducted to determine the level of recognition of zoonotic parapoxvirus infections and prevention measures, the degree to which veterinarians may be consulted on human infections and what forces were behind this perceived increase in reported infections. Interviews were conducted and clinical and environmental sampling was performed.

Effective antiviral treatment of systemic orthopoxvirus disease: ST-246 treatment of prairie dogs infected with monkeypox virus.

Smallpox preparedness research has led to development of antiviral therapies for treatment of serious orthopoxvirus infections. Monkeypox virus is an emerging, zoonotic orthopoxvirus which can cause severe and transmissible disease in humans, generating concerns for public health. Monkeypox virus infection results in a systemic, febrile-rash illness closely resembling smallpox.

Dosage comparison of Congo Basin and West African strains of monkeypox virus using a prairie dog animal model of systemic orthopoxvirus disease.

The prairie dog is valuable for the study of monkeypox virus (MPXV) virulence and closely resembles human systemic orthopoxvirus disease. Herein, we utilize a variable dose intranasal challenge with approximately 10(3), 10(4), 10(5), and 10(6)PFU for each clade to further characterize virulence differences between the two MPXV clades. A trend of increased morbidity and mortality as well as greater viral shedding was observed with increasing viral challenge dose.

A silent enzootic of an orthopoxvirus in Ghana, West Africa: evidence for multi-species involvement in the absence of widespread human disease.

Human monkeypox has never been reported in Ghana, but rodents captured in forested areas of southern Ghana were the source of the monkeypox virus introduced into the United States in 2003. Subsequent to the outbreak in the United States, 204 animals were collected from two commercial trapping sites in Ghana. Animal tissues were examined for the presence of orthopoxvirus (OPXV) DNA using a real-time polymerase chain reaction, and sera were assayed for antibodies against OPXV.

The phylogenetics and ecology of the orthopoxviruses endemic to North America.

The data presented herein support the North American orthopoxviruses (NA OPXV) in a sister relationship to all other currently described Orthopoxvirus (OPXV) species. This phylogenetic analysis reaffirms the identification of the NA OPXV as close relatives of "Old World" (Eurasian and African) OPXV and presents high support for deeper nodes within the Chordopoxvirinae family. The natural reservoir host(s) for many of the described OPXV species remains unknown although a clear virus-host association exists between the genus OPXV and several mammalian taxa.

A prairie dog animal model of systemic orthopoxvirus disease using West African and Congo Basin strains of monkeypox virus.

Multiple monkeypox virus (MPXV) animal models have been discussed in previous studies, but no small animal models, nor most non-human primate models, demonstrated the protracted asymptomatic incubation phase seen in systemic human orthopoxvirus illness. Herein, we characterize a black-tailed prairie dog (PD) (Cynomys ludovicianus) model of infection, via intranasal and intradermal exposures, with the two MPXV clades. Daily observations of the animals were made (food consumption, general symptoms, disease presentation), while weights and virus evaluations (ocular, nasal, oropharyngeal, faeces, blood) were obtained/made every third day.

Eczema vaccinatum resulting from the transmission of vaccinia virus from a smallpox vaccinee: an investigation of potential fomites in the home environment.

On March 3, 2007, a 2-year-old boy was hospitalized with eczema vaccinatum. His two siblings, one with eczema, were subsequently removed from the home. Swabs of household items obtained on March 13th were analyzed for orthopoxvirus DNA signatures with real-time PCR.

Transmission of atypical varicella-zoster virus infections involving palm and sole manifestations in an area with monkeypox endemicity.

During a suspected monkeypox outbreak in the Republic of Congo, we documented transmission of varicella-zoster virus (VZV) infection with palm and sole manifestations among 5 family members. Genotyping results confirmed the VZV strain European E2, a genotype not previously reported in Africa. VZV with palm and sole involvement should be considered when differentiating a monkeypox diagnosis.

Real-time PCR assay to identify variants of Vaccinia virus: implications for the diagnosis of bovine vaccinia in Brazil.

Naturally occurring infections of Vaccinia virus (VACV) have been recognized in Brazil during the past 10 years. Human Brazilian Vaccinia virus (BVV) infections typically occur as a zoonosis transferred from affected dairy cows to their handlers. Outbreaks have caused notable economic losses to the rural community in the region.

Severe eczema vaccinatum in a household contact of a smallpox vaccinee.

Background: We report the first confirmed case of eczema vaccinatum in the United States related to smallpox vaccination since routine vaccination was discontinued in 1972. A 28-month-old child with refractory atopic dermatitis developed eczema vaccinatum after exposure to his father, a member of the US military who had recently received smallpox vaccine. The father had a history of inactive eczema but reportedly reacted normally to the vaccine.

Prevalence of antibodies against orthopoxviruses among residents of Likouala region, Republic of Congo: evidence for monkeypox virus exposure.

Monkeypox virus is a zoonotic orthopoxvirus (OPX) of west and central sub-Saharan Africa. We conducted a cross-sectional serosurvey in Likouala region, Republic of Congo to assess exposure to OPX. Whole blood was collected using Nobuto blood filter strips (NBFS).

Monkeypox zoonotic associations: insights from laboratory evaluation of animals associated with the multi-state US outbreak.

At the onset of the 2003 US monkeypox outbreak, virologic data were unavailable regarding which animal species were involved with virus importation and/or subsequent transmission to humans and whether there was a risk for establishment of zoonotic monkeypox in North America. Similarly, it was unclear which specimens would be best for virus testing. Monkeypox DNA was detected in at least 33 animals, and virus was cultured from 22.

A tale of two clades: monkeypox viruses.

Human monkeypox was first recognized outside Africa in 2003 during an outbreak in the USA that was traced to imported monkeypox virus (MPXV)-infected West African rodents. Unlike the smallpox-like disease described in the Democratic Republic of the Congo (DRC; a Congo Basin country), disease in the USA appeared milder. Here, analyses compared clinical, laboratory and epidemiological features of confirmed human monkeypox case-patients, using data from outbreaks in the USA and the Congo Basin, and the results suggested that human disease pathogenicity was associated with the viral strain.

Smallpox vaccine stability after maintenance at temperatures not recommended for shipping.

Two distinct smallpox vaccine formulations were exposed to temperatures beyond the ranges specified by the manufacturers for vaccine maintenance and shipping. Under the conditions investigated, titers of both Dryvax smallpox vaccine and Aventis Pasteur smallpox vaccine remained at or above the titers recommended for successful vaccination. From these data it can be inferred that vaccine efficacy would not be expected to be adversely affected by unintended fluctuations of temperature, within the ranges studied, for a 4-day period.

Stability of diluted smallpox vaccine under simulated clinical conditions.

Context: During a mass smallpox immunization campaign, vaccine may be exposed to ambient temperatures for extended periods of time.

Objective: To determine the viability of undiluted and 5x diluted DryVax smallpox vaccine after cycling vaccine in and out of refrigeration for 2 weeks, as might occur during an immunization campaign.

Design: Two vials of Dryvax vaccine were reconstituted as per manufacturer's instructions (1x) and two vials were reconstituted using 5x the recommended diluent (5x).

Human monkeypox infection: a family cluster in the midwestern United States.

Background: The outbreak of monkeypox in the Midwestern United States during June 2003 marks the first documented human infection in the Western Hemisphere. Consistent with those in outbreaks in Africa, most cases in this outbreak were associated with febrile rash illness. We describe a cluster of monkeypox in a family with a spectrum of clinical illness, including encephalitis, and outline the laboratory confirmation of monkeypox.

Population genetic analysis of Bartonella bacilliformis isolates from areas of peru where Carrion's disease is endemic and epidemic.

Carrion's disease is caused by infection with the alpha-proteobacterium Bartonella bacilliformis. Distribution of the disease is considered coincident with the distribution of its known vector, the sand fly Lutzomyia verrucarum. Recent epidemics of B.

Monkeypox transmission and pathogenesis in prairie dogs.

During May and June 2003, the first cluster of human monkeypox cases in the United States was reported. Most patients with this febrile vesicular rash illness presumably acquired the infection from prairie dogs. Monkeypox virus was demonstrated by using polymerase chain reaction in two prairie dogs in which pathologic studies showed necrotizing bronchopneumonia, conjunctivitis, and tongue ulceration.

The detection of monkeypox in humans in the Western Hemisphere.

Background: During May and June 2003, an outbreak of febrile illness with vesiculopustular eruptions occurred among persons in the midwestern United States who had had contact with ill pet prairie dogs obtained through a common distributor. Zoonotic transmission of a bacterial or viral pathogen was suspected.

Methods: We reviewed medical records, conducted interviews and examinations, and collected blood and tissue samples for analysis from 11 patients and one prairie dog.

Prevalence of Bartonella infection among human immunodeficiency virus-infected patients with fever.

Bartonella infection can be difficult to diagnose, especially when it manifests as bacteremia, which is usually accompanied by nonspecific symptoms, such as fever. Therefore, we hypothesized that Bartonella infection represents an underrecognized cause of febrile illness. To determine the prevalence of Bartonella infection among patients presenting with fever, we evaluated 382 patients in San Francisco.