A Focus of Dogs and Rickettsia massiliae–Infected Rhipicephalus sanguineus in California

Abstract

Abstract. A recurrent focus of Rhipicephalus sanguineus infestation was investigated in a suburban area of southern California after reports of suspected Rocky Mountain spotted fever in two dogs on the same property. Abundant quantities of Rh. sanguineus were collected on the property and repeatedly from each dog, and Rickettsia massiliae DNA was detected by polymerase chain reaction (PCR). Whole blood and serum samples from four dogs were tested by using PCR and microimmunofluorescent assay for antibodies against spotted fever group rickettsiae. Serum samples from all four dogs contained antibodies reactive with R. massiliae , R. rhipicephali , R. rickettsii , and 364D Rickettsia but no rickettsial DNA was detected by PCR of blood samples. Serum cross-absorption and Western blot assays implicated R. massiliae as the most likely spotted fever group rickettsiae responsible for seropositivity. To our knowledge, this is the first detection of R. massiliae in ticks in California.

Detección molecular de Rickettsia massiliae y Anaplasma platys en garrapatas Rhipicephalus sanguineus y caninos domésticos del municipio de Bahía Blanca (Argentina)

“…Rickettsia massiliae ha sido detectada en garrapatas del género Rhipicephalus con diversos niveles de infección, de 2,5-18% en Europa 25,26 , 5-6% en África 27,28 , 25% en Israel 29 hasta más de 25% en Estados Unidos de América 9,30 . En Sudamérica, sólo había sido detectada en CABA, con un nivel de infección de 3,4 16 a 20% 31 .…”

“…en caninos domésticos, aunque, al igual que en nuestro estudio, no se pudo detectar en sangre mediante RPC 9,16,31 . En caninos, R. conorii y R. rickettsii producen rickettsemia detectable del día 2 al 12 luego de la infección; sin embargo, no se ha comprobado su susceptibilidad a R. massiliae 9 . Por ello, se necesitan estudios complementarios para dilucidar el rol de los caninos como reservorios de este patógeno.…”

“…Los signos clínicos incluyen fiebre, cefalea, lesión necrótica en el sitio de picadura de la garrapata, erupción purpúrica maculo-papular en extremidades, espalda, palmas de las manos y plantas de los pies, y también afección ocular con disminución aguda bilateral de la visión asociada a corio-retinitis 4,5,7,8 . En caninos domésticos también podría causar enfermedad, con signos similares a otras rickettsiosis caninas, tales como fiebre, anorexia, mialgias, signos neurológicos, presencia de edema e hiperemia en labios, prepucio, escroto, orejas y extremidades, y lesiones oculares 4,9 . Anaplasma platys presenta distribución mundial y se transmite por garrapatas R. sanguineus, es el agente de la trombocitopenia cíclica infecciosa canina, afección generalmente leve, aunque con diversa patogenicidad www.sochinf.cl…”

The Biological Survey of Canada: A Personal History

“…Rickettsia massiliae was implicated as the cause of an RMSF-like illness in dogs in southern California, and was present in Rhipicephalus sanguineus collected from the area where the dogs lived (Beeler et al 2011). Rickettsia massiliae has not yet been detected from humans in North America, although the potential for human infection clearly exists.…”

National Surveillance of Spotted Fever Group Rickettsioses in the United States, 2008–2012

“…Several other SFG Rickettsia species, including Rickettsia massiliae, Rickettsia montanensis, and Rickettsia amblyommii have been isolated from ticks, and may cause some infections in humans, but have not yet been isolated from human specimens in the United States. [6][7][8][9] Speculation has arisen as to how often mildly pathogenic or nonpathogenic rickettsial species may be misdiagnosed as RMSF. 8,[10][11][12] The available serological assays for R. rickettsii cross react with other pathogens in the SFG Rickettsia, as well as member of the transitional group (TRG) Rickettsia, including Rickettsia akari and Rickettsia felis.…”