Laboratory-acquired vaccinia infection

Abstract Background: Complications following vaccination with vaccinia virus have been well described but are not commonly observed. The use of vaccinia as a tool in molecular biology, in the development of therapeutics, and the anticipated increase of vaccinations in the general population due to the threat of bioterrorism have created a renewed awareness of the post-vaccination complications and the consequent need for clinical and laboratory diagnosis. Objectives: To report the clinical presentation and subsequent diagnosis of generalized vaccinia that resulted from a laboratory accident in an unvaccinated subject. Study design: The patient was seen by a local infectious disease's specialist and evaluated clinically and with laboratory support relative to a differential diagnosis. Results: Careful assessment of the patient's history, an evaluation of the workplace, and the elimination of likely microbial etiologies led to the diagnosis of generalized vaccinia. Laboratory confirmation was obtained by use of electron microscopy (EM) to observe poxvirus particles in infected cell cultures. Conclusions: Exposure to vaccinia virus should raise the index of suspicion for patients with skin lesions. Rapid diagnosis may be accomplished by direct examination of lesion material by EM. The virus also readily replicates in commonly available cell cultures and in the absence of immune reagents, typical poxvirus particles may be observed in the infected cells by EM

The immunopathology of canine vector-borne diseases

The canine vector-borne infectious diseases (CVBDs) are an emerging problem in veterinary medicine and the zoonotic potential of many of these agents is a significant consideration for human health. The successful diagnosis, treatment and prevention of these infections is dependent upon firm understanding of the underlying immunopathology of the diseases in which there are unique tripartite interactions between the microorganism, the vector and the host immune system. Although significant advances have been made in the areas of molecular speciation and the epidemiology of these infections and their vectors, basic knowledge of the pathology and immunology of the diseases has lagged behind. This review summarizes recent studies of the pathology and host immune response in the major CVBDs (leishmaniosis, babesiosis, ehrlichiosis, hepatozoonosis, anaplasmosis, bartonellosis and borreliosis). The ultimate application of such immunological investigation is the development of effective vaccines. The current commercially available vaccines for canine leishmaniosis, babesiosis and borreliosis are reviewed

Does co-infection with vector-borne pathogens play a role in clinical canine leishmaniosis?

The severity of canine leishmaniosis (CanL) due to Leishmania infantum might be affected by other vector-borne organisms that mimic its clinical signs and clinicopathological abnormalities. The aim of this study was to determine co-infections with other vector-borne pathogens based on serological and molecular techniques in dogs with clinical leishmaniosis living in Spain and to associate them with clinical signs and clinicopathological abnormalities as well as disease severity. Sixty-one dogs with clinical leishmaniosis and 16 apparently healthy dogs were tested for Rickettsia conorii, Ehrlichia canis, Anaplasma phagocytophilum and Bartonella henselae antigens by the immunofluorescence antibody test (IFAT) and for E. canis, Anaplasma spp., Hepatozoon spp., Babesia spp. and filarioid DNA by polymerase chain reaction (PCR). Among the dogs examined by IFAT, the seroprevalences were: 69% for R. conorii, 57% for E. canis, 44% for A. phagocytophilum and 37% for B. henselae ; while the prevalences found by PCR were: 8% for Ehrlichia / Anaplasma, 3% for Anaplasma platys and 1% for H. canis. No other pathogen DNA was detected. Statistical association was found between dogs with clinical leishmaniosis and seroreactivity to R. conorii antigen (Fisher's exact test: P = 0.025, OR = 4.1, 95% CI = 1-17) and A. phagocytophilum antigen (Fisher's exact test: P = 0.002, OR = 14.3, 95% CI = 2-626) and being positive to more than one serological or molecular tests (co-infections) (Mann-Whitney test: U = 243, Z = -2.6, n = 14, n = 61, P = 0.01) when compared with healthy dogs. Interestingly, a statistical association was found between the presence of R. conorii, E. canis, A. phagocytophilum and B. henselae antibodies in sick dogs and some clinicopathological abnormalities such as albumin and albumin/globulin ratio decrease and increase in serum globulins. Furthermore, seroreactivity with A. phagocytophilum antigens was statistically associated with CanL clinical stages III and IV. This study demonstrates that dogs with clinical leishmaniosis from Catalonia (Spain) have a higher rate of co-infections with other vector-borne pathogens when compared with healthy controls. Furthermore, positivity to some vector-borne pathogens was associated with more marked clinicopathological abnormalities as well as disease severity with CanL