Rickettsial Infections around the World, Part 1: Pathophysiology and the Spotted Fever Group

2005 ◽  
Vol 9 (2) ◽  
pp. 54-62
Author(s):  
Jashin J. Wu ◽  
David B. Huang ◽  
Katie R. Pang ◽  
Stephen K. Tyring
Keyword(s):  
Spotted Fever ◽  
Clinical Manifestations ◽  
Review Article ◽  
Learning Activity ◽  
Clinical Aspects ◽  
Spotted Fever Group ◽  
Infectious Agents ◽  
Important Group ◽  
Rickettsial Infections ◽  
Rickettsial Diseases

Background: The rickettsial diseases are an important group of infectious agents that have dermatological manifestations. These diseases are important to consider in endemic areas, but in certain suspicious cases, possible acts of bioterrorism should warrant prompt notification of the appropriate authorities. Objective: In this two part review article, we review these diverse diseases by examining established and up-to-date information about the pathophysiology, epidemiology, clinical manifestations, and treatment of the ricksettsiae. Methods: Using PubMed to search for relevant articles, we browsed over 500 articles to compose a clinically based review article. Results: Part one focuses on pathophysiology of the rickettsial diseases and the clinical aspects of the spotted fever group. Conclusions: At the completion of part one of this learning activity, participants should be able to discuss all of the clinical manifestations and treatments of the sported fever group. Participants should also be familiar with the pathophysiology of the rickettsial diseases.

scholarly journals Spotted fever rickettsiosis in Coronel Fabriciano, Minas Gerais State

2003 ◽  
Vol 36 (4) ◽  
pp. 479-481 ◽  
Author(s):  
Márcio Antônio Moreira Galvão ◽  
Simone Berger Calic ◽  
Chequer Buffe Chamone ◽  
Cláudio Lísias Mafra S. ◽  
Gracco Cesarino Filho ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Spotted Fever ◽  
Clinical Manifestations ◽  
Minas Gerais ◽  
Spotted Fever Group ◽  
Minas Gerais State ◽  
Brazilian Spotted Fever ◽  
Spotted Fever Group Rickettsia ◽  
Rickettsial Diseases

We report cases of spotted fever rickettsiosis in Coronel Fabriciano Municipality of Minas Gerais State, Brazil. The cases occurred in May and June of 2000. During this period there were two deaths among children from an area named Pedreira in a periurban area of this municipality. In a boy who died with clinical manifestations of Brazilian spotted fever, a necropsy revealed the presence of a spotted fever group Rickettsia. The serological results confirm the difficulty in the differential diagnosis of patients with symptoms of rickettsial diseases.

scholarly journals Molecular and serological evidence of flea-associated typhus group and spotted fever group rickettsial infections in Madagascar

2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Rado J. L. Rakotonanahary ◽  
Alan Harrison ◽  
Alice N. Maina ◽  
Ju Jiang ◽  
Allen L. Richards ◽  
...  
Keyword(s):  
Spotted Fever ◽  
Spotted Fever Group ◽  
Serological Evidence ◽  
Rickettsial Infections

scholarly journals Diagnosis of spotted fever group Rickettsia infections: the Asian perspective

2019 ◽  
Vol 147 ◽  
Author(s):  
Matthew T. Robinson ◽  
Jaruwan Satjanadumrong ◽  
Tom Hughes ◽  
John Stenos ◽  
Stuart D. Blacksell
Keyword(s):  
Positive Result ◽  
Diagnostic Tests ◽  
Quantitative Polymerase Chain Reaction ◽  
Spotted Fever ◽  
Emerging Infectious Diseases ◽  
Immunofluorescence Assay ◽  
Diagnostic Methods ◽  
Spotted Fever Group ◽  
Sample Collection ◽  
Rickettsial Infections

Abstract Spotted fever group rickettsiae (SFG) are a neglected group of bacteria, belonging to the genus Rickettsia, that represent a large number of new and emerging infectious diseases with a worldwide distribution. The diseases are zoonotic and are transmitted by arthropod vectors, mainly ticks, fleas and mites, to hosts such as wild animals. Domesticated animals and humans are accidental hosts. In Asia, local people in endemic areas as well as travellers to these regions are at high risk of infection. In this review we compare SFG molecular and serological diagnostic methods and discuss their limitations. While there is a large range of molecular diagnostics and serological assays, both approaches have limitations and a positive result is dependent on the timing of sample collection. There is an increasing need for less expensive and easy-to-use diagnostic tests. However, despite many tests being available, their lack of suitability for use in resource-limited regions is of concern, as many require technical expertise, expensive equipment and reagents. In addition, many existing diagnostic tests still require rigorous validation in the regions and populations where these tests may be used, in particular to establish coherent and worthwhile cut-offs. It is likely that the best strategy is to use a real-time quantitative polymerase chain reaction (qPCR) and immunofluorescence assay in tandem. If the specimen is collected early enough in the infection there will be no antibodies but there will be a greater chance of a PCR positive result. Conversely, when there are detectable antibodies it is less likely that there will be a positive PCR result. It is therefore extremely important that a complete medical history is provided especially the number of days of fever prior to sample collection. More effort is required to develop and validate SFG diagnostics and those of other rickettsial infections.

Clinical Features of Rickettsial Infection in Children in Tropical Australia—A Report of 15 Cases

2020 ◽  
Vol 66 (6) ◽  
pp. 655-660 ◽  
Author(s):  
Alexandra G A Stewart ◽  
Simon Smith ◽  
Enzo Binotto ◽  
Josh Hanson
Keyword(s):  
Scrub Typhus ◽  
Spotted Fever ◽  
Case Fatality ◽  
Spotted Fever Group ◽  
Tertiary Referral Hospital ◽  
Admission Rates ◽  
Rickettsial Infections ◽  
Retrospective Audit ◽  
Tropical Australia ◽  
The Tropics

Abstract Rickettsial infections are an under-recognized cause of acute, undifferentiated fever in the tropics. In Asia, intensive care unit (ICU) admission rates as high as 21% and case-fatality rates of up to 5% have been reported. This 20-year retrospective audit of children and adults with serologically confirmed scrub typhus or spotted fever group (SFG) infection was performed at a tertiary-referral hospital in tropical Australia. There were 15 paediatric cases during the study period (11 scrub typhus, 3 SFG and 1 undifferentiated). Hypotension [5/15 (33%)], tachycardia [6/15 (40%)] and tachypnoea [6/15 (40%)] were common at presentation. Children were more likely to be hypotensive at admission than adults [5/15 (33%) vs. 5/118 (4%), p = 0.002]. However, no child died or was admitted to ICU, compared with 18/120 (15%) adults who required ICU support during the study period, one of whom died. Paediatric rickettsial infections have a relatively benign clinical course in tropical Australia with serious complications appearing far less frequently than have been reported in the Asian literature.

Spotted Fever Group Rickettsial Infections in Australia

1991 ◽  
Vol 13 (5) ◽  
pp. 876-886 ◽  
Author(s):  
D. J. Sexton ◽  
B. Dwyer ◽  
R. Kemp ◽  
S. Graves
Keyword(s):  
Spotted Fever ◽  
Spotted Fever Group ◽  
Rickettsial Infections

Rickettsial Infections Around the World, Part 1: Pathophysiology and the Spotted Fever Group

2005 ◽  
Vol 9 (2) ◽  
pp. 54-62 ◽  
Author(s):  
Jashin J. Wu ◽  
David B. Huang ◽  
Katie R. Pang ◽  
Stephen K. Tyring
Keyword(s):  
Spotted Fever ◽  
Spotted Fever Group ◽  
Rickettsial Infections ◽  
The World

Tick-borne rickettsial diseases

2011 ◽  
Author(s):  
Emmanouil Angelakis ◽  
Didier Raoult
Keyword(s):  
Spotted Fever ◽  
Reservoir Host ◽  
Spotted Fever Group ◽  
Rickettsia Species ◽  
The Family ◽  
Risk Areas ◽  
Vertebrate Hosts ◽  
Group 2 ◽  
Rickettsial Diseases ◽  
Rickettsia Bellii

Bacteria of the genus Rickettsia belong to the family Rickettsiaceae in the order Rickettsiales and have for long been described simply as short, Gram-negative, strict intracellular rods that retain basic fuchsin when stained by the method of Gimenez (Raoult and Roux 1997). These bacteria are associated with ticks, lice, fleas or mites. To date the Rickettsia genus contains 24 recognized species classified into three groups based on their antigenic, morphological, and ecologic patterns: 1) the typhus group, 2) the spotted fever group and 3) Rickettsia bellii (Fournier and Raoult 2007). Most spotted fever group (SFG) rickettsiae are closely associated with ticks belonging to the family Ixodidae (also called “hard” ticks) (Parola et al. 2005). Ticks can act as vectors, reservoirs, and/or amplifiers of SFG rickettsiae and require optimal environmental conditions which determine the geographic distribution of the vectors and consequently the risk areas for rickettsioses. Many Rickettsia species are strictly associated with one genus of ticks and the transmittion to people is made through the tick bite, which generally implies that the Rickettsia can localize to their salivary glands. Therefore, since larvae, nymphs, and adults may all be infective for susceptible vertebrate hosts, the ticks must be regarded as the main reservoir host of rickettsiae. Humans are not considered as good reservoirs for Rickettsiae, as they are seldom infested with ticks for long periods and rickettsiaemia has normally short duration, especially with antibiotic intervention.

Hospital based serological evidence of rickettsial diseases and assessment diagnostic tests of pyrexia of unknown origin

2019 ◽  
Vol 50 (2) ◽  
pp. 122-124
Author(s):  
Muzaheed ◽  
Amal J Fatani ◽  
Darshan D Divakar ◽  
Sanjay Rathod ◽  
Mustafa S Aloahd
Keyword(s):  
Scrub Typhus ◽  
Spotted Fever ◽  
Unknown Origin ◽  
Molecular Techniques ◽  
Serological Evidence ◽  
Serological Tests ◽  
Pyrexia Of Unknown Origin ◽  
Rickettsial Infections ◽  
Igm Elisa ◽  
Rickettsial Diseases

The present study examined hospital-based serological tests of rickettsial infections and assessment for diagnosis of pyrexia of unknown origin (PUO). Blood samples were tested for Weil Felix antigens, ELISA for scrub typhus group and polymerase chain reaction (PCR) to detect the presence of DNA of spotted and scrub typhus group with the help of specific oligonucleotide. We tested 450 patient samples and found 101 Weil Felix-positive with 15 having ≥320 titres. IgM ELISA identified 32 (7.1%) positive cases. Positive PCR was seen in 13 (2.9%) samples, being only 40.1% of those testing positive for ELISA. Rickettsial infection is predominantly diagnosed through serological evidence in combination with molecular techniques. The Weil Felix test has a number of disadvantages and tends to provide false-positive results in a number of scenarios, especially where scrub typhus and spotted fever are widely distributed.

LABORATORY CONFIRMATION OF THE SPOTTED FEVER GROUP RICKETTSIOSES AMONG PATIENTS WITH TYPICAL AND ATYPICAL CLINICAL MANIFESTATIONS

2020 ◽  
Author(s):  
T.A. Chekanova ◽  
Keyword(s):  
New Species ◽  
Primary Infection ◽  
Spotted Fever ◽  
Clinical Signs ◽  
Clinical Manifestations ◽  
Spotted Fever Group ◽  
Single Group ◽  
Laboratory Confirmation ◽  
Atypical Manifestations

In the group of patients with typical clinical signs of acute tick-borne rickettsioses, specific IgM and/or IgG with/without IgA were found in 75.6% cases. IgG were low avidity in most cases, which indicated the recent primary infection. More than 20% of sera have single group specific IgA. In patients with atypical manifestations highly avidity IgG were predominant, that along with the presence of IgM and/or IgA may indicate re-infection or infection by new species, which is different from previous pathogen of the tick-borne spotted group rickettsioses.

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