Case Report: Cardiovascular Manifestations Due to Flea-Borne Typhus
This paper has been added because it displays some of the effects of Rickettsia typhi.
Flea-borne typhus is caused by Rickettsia typhi and occurs worldwide, except in Antarctica. In the United States, most cases are seen in California, Hawaii, and Texas. It is characterized by fever, headache, rash, arthralgia, cough, hepatosplenomegaly, diarrhea, and abdominal pain. The cardiovascular system is rarely affected. We present a case of endocarditis resulting from flea-borne typhus diagnosed by blood microbial cell-free DNA testing the required valve replacement and antibiotic therapy for 6 months. Also, we review 20 cases of presumed and confirmed cardiovascular manifestations resulting from flea-borne typhus.
Murine Typhus: A Review of a Reemerging Flea-Borne Rickettsiosis with Potential for Neurologic Manifestations and Sequalae
This paper has been added because it highlights current knowledge of Rickettsia typhi and what needs further study.
Murine typhus is an acute febrile illness caused by Rickettsia typhi. Rats serve as the reservoir and their fleas serve as the vector. Humans can become infected when infected feces enter the body through wounds or mucous membranes. The disease is endemic throughout much of the world and is reemerging as an important cause of febrile illness in Texas and Southern California, likely through opossums and cat fleas. After infection, a range of neurologic manifestations may occur. Early empiric treatment with doxycycline is imperative. Thus, the purpose of this review is to highlight murine typhus as an important emerging and reemerging infectious disease, review its neurologic manifestations, and discuss areas in need of further study.
Rickettsia thypi in Southern California: A Growing Flea-Borne Threat
This opinion piece on increasing flea-borne typhus cases in Southern California looks through the publication “Surveillance of Flea-borne Typhus in California, 2011-2019.” Flea-borne typhus is the vector for Rickettsia typhi. It is classically maintained by rats and it likely utilizes opossums as an amplifying host in North America. Despite the difficulties in establishing a diagnosis, it has become clear that flea-borne typhus is becoming increasingly prevalent, causing some people to be hospitalized. The number of cases in California has been on the rise. With the ability of rats to thrive in the vicinity of humans, the broad geographic distribution of opossums, and the ubiquity of fleas, the resurgence of flea-borne typhus in other communities of California and in other states, is likely.
Surveillance of Flea-Borne Typhus in California, 2011-2019
This paper has been added because it highlights cases of flea-borne typhi.
Flea-borne typhus is an acute febrile disease in humans caused by the bacteria Rickettsia typhi. In this study, they characterized the epidemiology of flea-borne typhus cases in California from 2011 to 2019. A total of 881 cases were reported during this period. Demographics, animal exposures, and clinical courses for case patients were summarized. Additionally, spatiotemporal cluster analyses pointed to five areas in southern California with persistent flea-borne typhus transmission.
New records of pathogenic bacteria in different species of fleas collected from domestic and peridomestic animals in Spain. A potential zoonotic threat?
Fleas can play a significant role as vectors of pathogenic bacteria. Over a 19-month period, fleas were collected from dogs, cats, and hedgehogs, for a total of 812 fleas. Five different species including C. felis, C.canis, S. cuniculi, P. irritans, and A. erinacei. Wolbachia sp. was detected in all five species with a total prevalence rate of 86%. A total of 131 fleas tested positive for Bartonella sp., representing a prevalence rate of 16%. With the data, the list of bacterial zoonotic agents found in fleas in Spain was updated. This emphasizes the need for future research to assess and confirm the potential vectorial role of certain fleas.
Vector biology of the cat flea Ctenocephalides felis
C. felis is one of the most prevalent and widely dispersed vectors worldwide. Research of C. felis is behind research on other vectors and vector-borne pathogens. So, they aimed to review aspects of C. felis as a vector such as behavior, epidemiology, phylogenetics, immunology, and microbiome composition). They propose that future laboratory experimental infection should examine the vector-pathogen interface utilizing contemporary visualization, transcriptomic, and gene-editing techniques. They also acknowledge that further environmental sampling will inform the range and prevalence of C. felis and associated pathogens, improving the accuracy of vector and pathogen modeling to improve infection/infestation risk assessment and diagnostic recommendations.
A nowcast model to predict outdoor flea activity in real time for the contiguous United States
The cat flea, C. felis, is a competent vector for several zoonotic pathogens. Veterinarians recommend that both cats and dogs be routinely treated with medications to prevent flea infestation. A mathematical model was created based on weighted averaging over time to predict outdoor flea activity from weather conditions in the United States. The nowcast predictions displayed strong seasonal and geographic patterns, with predicted activity generally being highest in the summer months. This model is valuable for educating pet owners about the risk of fleas.