Bartonella henselae as a cause of acute-onset febrile illness in cats

A comparison of Bartonella henselae infection in immunocompetent and immunocompromised mice

Bartonellosis refers to disease caused by the Bartonella genus of bacteria. The breadth of disease manifestations associated with Bartonella is currently expanding and includes regional lymphadenopathy, rheumatic, ocular, and neurological disorders. The dearth of knowledge regarding diagnosis, treatment and pathogenesis of this disease can be partially attributed to the lack of a reliable small animal model for the disease. For this study, Bartonella henselae, the most common species associated with human disease, was injected into Swiss Webster (SW) mice. When the outcome indicated that productive infection did not occur, SCID/Beige (immune compromised) mice were inoculated. While SW mice may potentially harbor an acute infection, less than 10 days in length, the SCID/Beige model provided a sustained infection lasting up to 30-days. These data indicate that SCID/Beige mice can provide a model to study Bartonella infection, therapeutics, and vector dynamics in the future.

Exposure of Domestic Cats to Three Zoonotic Bartonella Species in the United States

Cat-associated Bartonella species, which include B. henselae, B. koehlerae, and B. clarridgeiae, can cause mild to severe illness in humans. In the present study, we evaluated 1362 serum samples obtained from domestic cats across the U.S. for seroreactivity against three species and two strain types of Bartonella associated with cats (B. henselae type 1, B. henselae type 2, B. koehlerae, and B. clarridgeiae) using an indirect immunofluorescent assay (IFA). Overall, the seroprevalence at the cutoff titer level of ≥1:64 was 23.1%. Seroreactivity was 11.1% and 3.7% at the titer level cutoff of ≥1:128 and at the cutoff of ≥1:256, respectively. The highest observation of seroreactivity occurred in the East South-Central, South Atlantic, West North-Central, and West South-Central regions. The lowest seroreactivity was detected in the East North-Central, Middle Atlantic, Mountain, New England, and Pacific regions. We observed reactivity against all four Bartonella spp. antigens in samples from eight out of the nine U.S. geographic regions.

Molecular Survey of Bartonella Species in Shelter Cats in Rio De Janeiro: Clinical, Hematological, and Risk Factors

The present study aimed to detect Bartonella DNA in cats belonging to shelters, and to evaluate risk factors, clinical signs, and hematological abnormalities associated with infection. Complete blood counts and screening for the presence of Bartonella DNA were performed on cats' ethylenediamine tetraacetic acid anticoagulant-blood samples. Eighty-three cats (39.9%) were positive for Bartonella species. Bartonella DNA was also detected in fleas and in the blood of cats infested by positive flea. Cats that had not been sterilized, had outdoor access, had histories of fights, and had concurrent flea infestation were more likely to be infected by Bartonella species (P < 0.05). Age and sex were not associated with infection. Fifty-one (38.6%) symptomatic cats were positive to Bartonella species (P > 0.05). Clinical conditions most commonly observed were signs of respiratory abnormality and Sporothrix species coinfection (P > 0.05). Regarding hematological changes, eosinophilia was associated with infection (P < 0.05). A high frequency of Bartonella species infection was found in shelter cats and highlights the importance of adequate flea-control programs to prevent infection in cats and consequently in adopters and other animals.

Role of vector-borne pathogens in the development of fever in cats: 1. Flea-associated diseases

PRACTICAL RELEVANCE

There has been increasing identification of vector-borne pathogens in cats presented to veterinary clinics around the world for evaluation of fever and the associated secondary effects, such as signs of depression and loss of appetite.

AIM

The aim of this article is to summarize the clinically relevant information concerning fever in cats that is associated with pathogens known or suspected to be vectored by fleas, with an emphasis on presenting clinical abnormalities and optimal diagnostic, treatment and prevention strategies. Fever in cats that is associated with pathogens vectored by ticks or sandflies is discussed in Part 2 of this article series.

A review on the occurrence of companion vector-borne diseases in pet animals in Latin America

Companion vector-borne diseases (CVBDs) are an important threat for pet life, but may also have an impact on human health, due to their often zoonotic character. The importance and awareness of CVBDs continuously increased during the last years. However, information on their occurrence is often limited in several parts of the world, which are often especially affected. Latin America (LATAM), a region with large biodiversity, is one of these regions, where information on CVBDs for pet owners, veterinarians, medical doctors and health workers is often obsolete, limited or non-existent. In the present review, a comprehensive literature search for CVBDs in companion animals (dogs and cats) was performed for several countries in Central America (Belize, Caribbean Islands, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Puerto Rico) as well as in South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana (British Guyana), Paraguay, Peru, Suriname, Uruguay, Venezuela) regarding the occurrence of the following parasitic and bacterial diseases: babesiosis, heartworm disease, subcutaneous dirofilariosis, hepatozoonosis, leishmaniosis, trypanosomosis, anaplasmosis, bartonellosis, borreliosis, ehrlichiosis, mycoplasmosis and rickettsiosis. An overview on the specific diseases, followed by a short summary on their occurrence per country is given. Additionally, a tabular listing on positive or non-reported occurrence is presented. None of the countries is completely free from CVBDs. The data presented in the review confirm a wide distribution of the CVBDs in focus in LATAM. This wide occurrence and the fact that most of the CVBDs can have a quite severe clinical outcome and their diagnostic as well as therapeutic options in the region are often difficult to access and to afford, demands a strong call for the prevention of pathogen transmission by the use of ectoparasiticidal and anti-feeding products as well as by performing behavioural changes.

Bartonellosis, One Health and all creatures great and small

BACKGROUND

Bartonellosis is a zoonotic infectious disease of worldwide distribution, caused by an expanding number of recently discovered Bartonella spp.

OBJECTIVES

This review serves as an update on comparative medical aspects of this disease, including the epidemiology, pathogenesis, clinical diagnosis, treatment and challenges.

RESULTS

Of comparative medical importance, Bartonella spp. are transmitted by several arthropod vectors, including fleas, keds, lice, sand flies, ticks and, potentially, mites and spiders. Prior to 1990, there was only one named Bartonella species (B. bacilliformis), whereas there are now over 36, of which 17 have been associated with an expanding spectrum of animal and human diseases. Recent advances in diagnostic techniques have facilitated documentation of chronic bloodstream and dermatological infections with Bartonella spp. in healthy and sick animals, in human blood donors, and in immunocompetent and immunocompromised human patients. The field of Bartonella research remains in its infancy and is rich in questions, for which patient relevant answers are badly needed. Directed Bartonella research could substantially reduce a spectrum of chronic and debilitating animal and human diseases, and thereby reduce suffering throughout the world.

CONCLUSION

A One Health approach to this emerging infectious disease is clearly needed to define disease manifestations, to establish the comparative infectious disease pathogenesis of this stealth pathogen, to validate effective treatment regimens and to prevent zoonotic disease transmission.

Molecular detection of Bartonella henselae in 11 Ixodes ricinus ticks extracted from a single cat

BACKGROUND

Bartonella henselae is a highly prevalent, vector-borne pathogen. Transmission to humans and animals by ticks is discussed controversially. Here, we present a case report, where eleven Ixodes ricinus ticks all harbouring B. henselae DNA were removed from one single cat.

RESULTS

The first feeding tick was tested positive for B. henselae DNA. The cat was also found to be seropositive for anti-B. henselae IgG antibodies (titer 1:640). Bartonella henselae was not cultivatable from cat blood. Ten more feeding ticks removed 7 months later contained also B. henselae DNA. Sequence analysis of the 16SrDNA and the 16S-23S internal transcribed spacer (ITS) region revealed 100% sequence homology between all ticks. Bartonella adhesin A (badA) and VirB/VirD4 type IV secretion system (virB) DNA were also detected in all ticks.

CONCLUSIONS

Our results indicate that cats may serve as a reservoir for adult ticks to acquire B. henselae. Whether this observation implies an increased threat for human and animal health needs to be resolved.

Bartonella spp. - a chance to establish One Health concepts in veterinary and human medicine

Infectious diseases remain a remarkable health threat for humans and animals. In the past, the epidemiology, etiology and pathology of infectious agents affecting humans and animals have mostly been investigated in separate studies. However, it is evident, that combined approaches are needed to understand geographical distribution, transmission and infection biology of “zoonotic agents”. The genus Bartonella represents a congenial example of the synergistic benefits that can arise from such combined approaches: Bartonella spp. infect a broad variety of animals, are linked with a constantly increasing number of human diseases and are transmitted via arthropod vectors. As a result, the genus Bartonella is predestined to play a pivotal role in establishing a One Health concept combining veterinary and human medicine.