Rickettsia sp. Strain Atlantic Rainforest Infection in a Patient from a Spotted Fever-Endemic Area in Southern Brazil

Krawczak, Felipe da Silva; Muñoz-Léal, Sebastián; Guztzazky, Ana Carolina; Oliveira, Stefan Vilges de; Santos, Fabiana Cristina Pereira dos; Angerami, Rodrigo Nogueira; Moraes‐Filho, Jonas; Souza, Júlio César de; Labruna, Marcelo B.

doi:10.4269/ajtmh.16-0192

Cited by 58 publications

(31 citation statements)

References 14 publications

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“…Since the discovery in 2010 of a rickettsial disease caused by an SFGR identical or very similar to Rickettsia sp. Atlantic rainforest Aa46, there have been four confirmed cases (12)(13)(14)(15), and hundreds more are suspected (15,20,65) in several states in Brazil. Although U.S. and South American strains of R. parkeri produce infections that are clinically similar to and frequently misdiagnosed as RMSF, there are no known deaths attributed to infection with R. parkeri.…”

Section: Discussionmentioning

confidence: 99%

Unique Strain of Rickettsia parkeri Associated with the Hard Tick Dermacentor parumapertus Neumann in the Western United States

Paddock

Allerdice

Karpathy

et al. 2017

Appl Environ Microbiol

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In 1953, investigators at the Rocky Mountain Laboratories in Hamilton, MT, described the isolation of a spotted fever group Rickettsia (SFGR) species from Dermacentor parumapertus ticks collected from black-tailed jackrabbits (Lepus californicus) in northern Nevada. Several decades later, investigators characterized this SFGR (designated the parumapertus agent) by using mouse serotyping methods and determined that it represented a distinct rickettsial serotype closely related to Rickettsia parkeri; nonetheless, the parumapertus agent was not further characterized or studied. To our knowledge, no isolates of the parumapertus agent remain in any rickettsial culture collection, which precludes contemporary phylogenetic placement of this enigmatic SFGR. To rediscover the parumapertus agent, adult-stage D. parumapertus ticks were collected from black-tailed jackrabbits shot or encountered as roadkills in Arizona, Utah, or Texas from 2011 to 2016. A total of 339 ticks were collected and evaluated for infection with Rickettsia species. Of 112 D. parumapertus ticks collected in south Texas, 16 (14.3%) contained partial ompA sequences with the closest identity (99.6%) to Rickettsia sp. strain Atlantic rainforest Aa46, an SFGR that is closely related or identical to an SFGR species that causes a mild rickettsiosis in several states of Brazil. A pure isolate, designated strain Black Gap, was cultivated in Vero E6 cells, and sequence analysis of the rrs, gltA, sca0, sca5, and sca4 genes also revealed the closest genetic identity to Rickettsia sp. Atlantic rainforest Aa46. Phylogenetic analysis of the five concatenated rickettsial genes place Rickettsia sp. strain Black Gap and Rickettsia sp. Atlantic rainforest Aa46 with R. parkeri in a distinct and well-supported clade.IMPORTANCE We suggest that Rickettsia sp. Black Gap and Rickettsia sp. Atlantic rainforest Aa46 represent nearly identical strains of R. parkeri and that Rickettsia sp. Black Gap or a very similar strain of R. parkeri represents the parumapertus agent. The close genetic relatedness among these taxa, as well as the response of guinea pigs infected with the Black Gap strain, suggests that R. parkeri Black Gap could cause disease in humans. The identification of this organism could also account, at least in part, for the remarkable differences in severity ascribed to Rocky Mountain spotted fever (RMSF) among various regions of the American West during the early 20th century. We suggest that the wide variation in case fatality rates attributed to RMSF

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Section: Discussionmentioning

confidence: 99%

Unique Strain of Rickettsia parkeri Associated with the Hard Tick Dermacentor parumapertus Neumann in the Western United States

Paddock

Allerdice

Karpathy

et al. 2017

Appl Environ Microbiol

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“…After this report, new human cases related to Rickettsia sp. Atlantic rainforest have been documented from Brazilian patients from Bahia and Santa Catarina states (SILVA et al, 2011;KRAWCZAK et al, 2016c). Research to unveil its epidemiology has identified the tick Amblyomma ovale as its main vector (KRAWCZAK et al, 2016a).…”

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confidence: 99%

First molecular detection of Rickettsia sp. strain Atlantic rainforest in Amblyomma ovale ticks from Espírito Santo state, Brazil

Acosta

Luz

Faccini-Martínez

et al. 2018

Rev. Bras. Parasitol. Vet.

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Espírito Santo state (southeastern Brazil) is considered an endemic area for spotted fever group rickettsioses. In February 2017, we received in our laboratory seven unfed Amblyomma ovale adult ticks collected by a farmer from his clothes and body (not attached) during a working day in the rural area of Ibiraçu municipality, Espírito Santo state. By polymerase chain reaction (PCR) analyses, targeting gltA and ompA rickettsial genes, the DNA of Rickettsia was detected in 6/7 (85.7%) A. ovale. In all cases, DNA sequencing of PCR products revealed that consensus sequences of both genes were 100% identical to gltA and ompA corresponding sequences of Rickettsia sp. strain Atlantic rainforest retrieved from GenBank. This study reports the first molecular detection of Rickettsia sp. strain Atlantic rainforest in A. ovale ticks from Espírito Santo state. Our findings indicate a new Brazilian state in the southeast region at risk of human infection with this tick-borne emerging rickettsial agent.

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“…In the context of rickettsial diseases and infections, the presence of lymphadenopathy has been described in infections by other rickettsial species, including R. parkeri , and the Rickettsia sp. strain Atlantic Rainforest of in Brazil (Spolidorio et al., ; Silva et al., ; Krawczak et al., ; Vizzoni et al., ). Lymphadenopathy has been reported in 49% of cases in an endemic region in southern Brazil, particularly in the state of Santa Catarina, where the clinical profile of SF is often one of a mild illness without reports of death (Angerami et al., ).…”

Section: Discussionmentioning

confidence: 99%

“…strain Atlantic Rainforest, a species closely related to Rickettsia sibirica , Rickettsia parkeri and Rickettsia africae . Its clinical manifestations are milder, and its common characteristics include the presence of inoculation eschars and lymphadenopathy (Angerami et al., ; Spolidorio et al., ; Silva et al., ; Vizzoni et al., ; Krawczak et al., ; Moerbeck et al., ). However, in the south‐eastern region of Brazil, the most serious form of the disease occurs.…”

Section: Introductionmentioning

confidence: 99%

Predictive Factors for Fatal Tick‐Borne Spotted Fever in Brazil

Oliveira

Willemann²,

Angerami

et al. 2017

Zoonoses and Public Health

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In Brazil, two pathogenic Rickettsia species have been identified causing tick-borne spotted fever (SF). The aetiological agent Rickettsia rickettsii causes serious illness, particularly in the south-eastern region of the country. Moreover, the Rickettsia sp. strain Atlantic Rainforest cause milder clinical manifestations in south-eastern, south and north-east regions. This study has sought to analyse predictive factors for fatal SF. A case-control study was performed using disease notification records in Brazil. The cases included were individuals with laboratory confirmation and fatal progression of SF, while the controls included individuals with SF who were cured. A total of 386 cases and 415 controls were identified (1 : 1.1), and the cases and controls were similar in age. The factors identified as being protective against death were reported presence of ticks (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.41-0.88), residing in urban areas (OR, 0.47, 95% CI, 0.31-0.74) and presenting lymphadenopathy (OR, 0.43; 95% CI, 0.23-0.82). Males exhibited a greater chance of death (OR, 1.57; 95% CI, 1.13-2.18), as did patients who were hospitalized (OR, 10.82; 95% CI, 6.38-18.35) and who presented hypotension or shock (OR, 10.80; 95% CI, 7.33-15.93), seizures (OR, 11.24; 95% CI, 6.49-19.45) and coma (OR of 15.16; 95% CI, 8.51-27.02). The study demonstrates the severity profile of the SF cases, defined either as the frequency of hospitalization (even in cases that were cured) or as the increased frequency of the clinical complications typically found in critical patients. Opportune clinical diagnosis, a careful evaluation of the epidemiological aspects of the disease and adequate care for patients are determining factors for reducing SF fatality rates.

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Rickettsia sp. Strain Atlantic Rainforest Infection in a Patient from a Spotted Fever-Endemic Area in Southern Brazil

Cited by 58 publications

References 14 publications

Unique Strain of Rickettsia parkeri Associated with the Hard Tick Dermacentor parumapertus Neumann in the Western United States

Unique Strain of Rickettsia parkeri Associated with the Hard Tick Dermacentor parumapertus Neumann in the Western United States

First molecular detection of Rickettsia sp. strain Atlantic rainforest in Amblyomma ovale ticks from Espírito Santo state, Brazil

Predictive Factors for Fatal Tick‐Borne Spotted Fever in Brazil

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