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PubMed2004

No serological evidence of Rickettsia helvetica infection in Scandinavian sarcoidosis patients.

Many agents have been suggested to elicit sarcoidosis, and, recently, an association was presented between this disease and the bacterium Rickettsia helvetica. The aim of this study was to investigate if serological support for such an association could be detected. Sera from 20 well-characterised sarcoidosis patients were investigated for anti-rickettsial immunoglobulin G antibodies with a micro-immunofluorescence technique. R. helvetica, R. conorii and R. typhi served as antigens. In conclusion, none of the investigated sera displayed detectable titres of anti-rickettsial immunoglobulin G antibodies. Thus, the current study does not support an association between rickettsia and sarcoidosis.

Adult↗
PubMed1987

Evidence for infection caused by spotted fever group Rickettsia in Kyushu, Japan.

Of 50 cases that gave negative immunofluorescence reaction with Rickettsia tsutsugamushi among patients with suspected tsutsugamushi disease encountered in Miyazaki Prefecture during the last four years, three showed a significant rise in the antibody titer to Rickettsia montana, a species of spotted fever group. This paper reports evidence for the occurrence of the rickettsial infection of the spotted fever group in Kyushu, Japan.

Adult↗
PubMed2000

Prevalence of spotted fever rickettsial antibodies in dogs and rodents in the Philippines.

Antibodies against spotted fever group rickettsiae have been detected in blood samples of dogs and rodents obtained from selected areas in the Philippines. In this serosurvey, the positive percentage rates are 8.3% (11/132) in dogs and 12.2% (6/49) in rats. Positive results were read from samples tested with Rickettsia japonica antigen. No positive result was obtained in blood samples of rats and house mice using R. akari antigen. The findings of this study are the first to confirm the detection of spotted fever group rickettsial antibodies in the Philippines.

Animals↗
PubMedDate not supplied

Virological investigations in adults with acute pneumonia.

Virological investigations (immunofluorescence reactions and isolation attempts with pharyngeal exudate specimens, as well as serological tests) were performed in 110 adult patients with pneumonia. Viral or inframicrobial agents were involved in 70 (63.7%) of the cases, either alone (27 cases) or in association with bacteria (43 cases). Parainfluenza and adenoviruses were most frequently encountered both in the cases with mixed (viral + bacterial) and in those with strictly viral pneumonia. Mycoplasma pneumoniae accounted for 11% of the cases; the role of chlamydial and rickettsial germs was insignificant.

Acute Disease↗
PubMed1988

A study of viral and rickettsial exposure and causes of fever in Juba, southern Sudan.

Patients presenting at the Juba Teaching Hospital, either with fever of undetermined origin or with a clinical cause of fever, gave evidence of exposure to a wide range of viral and rickettsial agents. Serological tests showed high antibody levels to flaviviruses (56.9%) and alphaviruses (29.2%), with lesser levels of bunyamweraviruses (3.8%), Rift Valley fever (2.3%), and sandfly fever (0.75%). Flavivirus exposure was significantly associated with clinical evidence of liver disease; repeated exposure to flaviviruses was particularly prevalent in those with poor sanitation and who had received previous injections. A significant focus of Ebola and Marburg exposure in Juba has been identified. Clinical evidence of liver disease was evident in 37% of patients studied, and 24.6% were HBsAg positive. The first 2 HIV-positive individuals from the southern Sudan are reported, including one with clinical AIDS. A high prevalence of positive antibodies to Rickettsia typhi in the population indicated that murine typhus was common locally. This study indicates the need for further public health measures in the southern Sudan to control the spread of these infections.

Adolescent↗
PubMed2005

Prevalence of Ehrlichia canis infection in thrombocytopenic dogs from Rio de Janeiro, Brazil.

BACKGROUND: Infection with Ehrlichia canis causes a highly variable, multisystemic disease in dogs. Nevertheless, many clinicians in Rio de Janeiro, Brazil, use the presence of only thrombocytopenia to make a presumptive diagnosis of E canis infection. OBJECTIVE: The objective of this study was to determine the prevalence of E canis in thrombocytopenic dogs from Rio de Janeiro, Brazil, using polymerase chain reaction (PCR). METHODS: Following DNA extraction of whole blood samples from 226 dogs, PCR assays were done using primers for rickettsial DNA (including Ehrlichia spp, Anaplasma platys and A phagocytophilum) and using E canis-specific primers (16S rRNA gene). Dogs were grouped as thrombocytopenic and nonthrombocytopenic based on platelet counts. The null hypothesis that there was no difference in the prevalence of E canis in these groups was rejected at P<.05. RESULTS: Thirty-six (32.1%) of the thrombocytopenic dogs and 4 (3.5%) of the nonthrombocytopenic dogs were positive for rickettsial gene sequences (P<.0001). Further, 30 (26.8%) of thrombocytopenic dogs and 4 (3.5%) nonthrombocytopenic dogs were positive for E canis-specific gene sequences (P<.0001). CONCLUSIONS: Although the prevalence of E canis infection was higher in thrombocytopenic dogs, less than one third of these dogs had demonstrable E canis infection. Thus, thrombocytopenia is not specific for the detection of E canis infection and should not be used solely to establish a diagnosis of canine ehrlichiosis, even in a geographic area with relatively high disease prevalence.

Animals↗
PubMed2006

Clinical and epidemiological features of hospitalized acute Q fever cases from Split-Dalmatia County (Croatia), 1985-2002.

BACKGROUND: Q fever shows a wide diversity of clinical manifestation. Q fever is endemic in northern Croatia, but the epidemiological and clinical characteristics of this disease in various ecological areas of southern Croatia are unclear. MATERIAL/METHODS: From January 1985 to December 2002, acute Q fever cases hospitalized at Split University Hospital were analyzed. Acute Q fever was defined as fever (>38 degrees C) with clinical findings in lung and/or liver verified by serologic testing with Coxiella burnetii phase II antigen. RESULTS: During the period of observation, 155 acute Q fever cases were hospitalized. The mean incidence of acute Q fever in the study region was 0.20/100,000/year (95%CI:0-0.78) in the coastal area and 4.64/100,000/year (95%CI:0.44-8.85) in the non-coastal areas, with a male predominance (chi2=60.0; p=0.0000) and a mean male to female ratio of 4.2:1. People of essentially all ages (4-76 years) were affected, the highest rate of infection being recorded in 20- to 49-year-old age groups. In contrast to adults, girls were more frequently affected than boys (2:1). No case of acute Q fever was recorded on any of the nearby islands. Clinically, acute Q fever most commonly presented with both pneumonia and hepatitis (60.0%), followed by pneumonia (25.8%), hepatitis (9.0%), and nonspecific febrile illnesses (5.2%). CONCLUSIONS: C. burnetii is endemic in rural, coastal, and non-coastal areas of southern Croatia and is associated with stock breeding. In these areas, Q fever occurs sporadically and epidemically. Males 20-49 years of age were the prevalent cases.

Acute Disease↗
PubMed1977

Q fever and animal abortion in Cyprus.

Seventy-eight British soldiers stationed in the Eastern Sovereign Base Area (ESBA) in Cyprus contracted Q fever in the period December 1974 to June 1975. Pneumonia developed in 59% of cases. Of 31 patients tested, 81% had biochemical evidence of hepatitis although only one became clinically jaundiced. Three patients (4%) suffered pericarditis. Treatment with tetracycline had no apparent effect on the course of the disease. Investigation revealed an abortion epidemic involving 21 mixed flocks of sheep and goats in the south-eastern coastal region. 11 of the flocks grazed in and around the ESBA. A serological survey of 10 affected flocks, and evidence collected from previous years, indicated that the abortion epidemic was the result of infection with Coxiella burneti. Infection in the humans was almost certainly acquired by inhalation of dust from brush contaminated with rickettsial parturition products of the aborting flocks. A human serological survey revealed a number of cases of subclinical Q fever in a susceptivle military population, and an asymptomatic epidemic in a largely immune local position.

Abortion, Veterinary↗
PubMed1984

Susceptibility and reservoir potential of the dog to spotted fever-group rickettsiae.

This study was initiated to determine the degree of susceptibility of dogs to virulent and nonvirulent spotted fever-group rickettsiae and to evaluate dogs as sources of infection for ticks. Dogs were exposed either by inoculation (syringe) or by infective tick bite to the following rickettsial serotypes: (1) Rickettsia rickettsii (Wachsmuth and Sawtooth female 2 strains), (2) R montana (M/5-6 B strain), and (3) R rhipicephali (3-7-female 6 strain). Results indicated that dogs inoculated with 1,000 or 10,000 egg infective doses of virulent R rickettsii developed a rickettsemia that was detectable as early as 4 days after inoculation to as late as 10 days. Conversely, none of the dogs inoculated with R montana (M/5-6 B) or R rhipicephali (3-7-female 6) or exposed to ticks infected with these strains developed detectable rickettsemia, fever, or other observable clinical signs. None of the 394 ticks that fed on rickettsemic dogs (R rickettsii) infected by inoculation became infected, and only 3 of 348 ticks (0.9% infection rate) were infected after feeding on dogs which had been infected by tick bite. All ticks fed on dogs exposed to R rhipicephali and R montana were shown to be free of rickettsiae. The largest concentrations of plaque-forming units (PFU) in Vero cell culture from undiluted whole blood were found on day 6 and on day 7 in dogs that were inoculated with 10,000 and 1,000 R rickettsii, respectively, of the Sawtooth female 2 strain. The highest rickettsial concentration observed for the dog infected by tick feeding was on day 9.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

Spectrum of disease and relation to place of exposure among ill returned travelers.

BACKGROUND: Approximately 8 percent of travelers to the developing world require medical care during or after travel. Current understanding of morbidity profiles among ill returned travelers is based on limited data from the 1980s. METHODS: Thirty GeoSentinel sites, which are specialized travel or tropical-medicine clinics on six continents, contributed clinician-based sentinel surveillance data for 17,353 ill returned travelers. We compared the frequency of occurrence of each diagnosis among travelers returning from six developing regions of the world. RESULTS: Significant regional differences in proportionate morbidity were detected in 16 of 21 broad syndromic categories. Among travelers presenting to GeoSentinel sites, systemic febrile illness without localizing findings occurred disproportionately among those returning from sub-Saharan Africa or Southeast Asia, acute diarrhea among those returning from south central Asia, and dermatologic problems among those returning from the Caribbean or Central or South America. With respect to specific diagnoses, malaria was one of the three most frequent causes of systemic febrile illness among travelers from every region, although travelers from every region except sub-Saharan Africa and Central America had confirmed or probable dengue more frequently than malaria. Among travelers returning from sub-Saharan Africa, rickettsial infection, primarily tick-borne spotted fever, occurred more frequently than typhoid or dengue. Travelers from all regions except Southeast Asia presented with parasite-induced diarrhea more often than with bacterial diarrhea. CONCLUSIONS: When patients present to specialized clinics after travel to the developing world, travel destinations are associated with the probability of the diagnosis of certain diseases. Diagnostic approaches and empiric therapies can be guided by these destination-specific differences.

Adult↗
PubMed1999

Antibodies reactive with Ehrlichia canis, Ehrlichia phagocytophila genogroup antigens and the spotted fever group rickettsial antigens, in free-ranging jackals (Canis aureus syriacus) from Israel.

A seroepidemiological survey was conducted to investigate the prevalence of antibodies reactive with the Ehrlichia canis and Ehrlichia phagocytophila genogroup antigens, and the spotted fever group (SFG) rickettsiae antigens in jackals in Israel (Canis aureus syriacus), to assess the possible role of the jackal in the epidemiology of these diseases. Fifty-three serum samples from jackals were assayed by the indirect immunofluorescence antibody test. Antibodies to E. canis were detected in 35.8% serum samples while 26.4% of the samples tested were positive to Ehrlichia chaffeensis. Twenty-six percent of the jackals tested were seropositive to E. phagocytophila, of which 5.7% were seropositive to E. phagocytophila alone without any seroreactivity to either E. canis or E. chaffeensis. Fifty-five percent of the jackals were seropositive to the SFG-rickettsiae antigens. The results suggest a high exposure rate of jackals in Israel to E. canis. Positive reactivity to E. chaffeensis was considered to be due to antigenic cross-reactions with E. canis. The study demonstrated for the first time the presence of E. phagocytophila antibodies in free-range jackals. The high incidence of antibodies to the SFG-rickettsiae and their relatively high antibody titers was suggestive of either recent or persistent infection. The possibility that jackals may play a role in the transmission of E. canis, E. phagocytophila and the SFG-rickettsiae for human and canine infections is discussed.

Animals↗
PubMed2003

Cross-protection between distantly related spotted fever group rickettsiae.

Two excellent C3H/HeN mouse models of spotted fever rickettsioses caused by the distantly related organisms, Rickettsia conorii and Rickettsia australis, were utilized to evaluate the possibility of the stimulation of broad cross-protective immunity. Sublethal infection stimulated complete immunity, that is absence of disease, after challenge with a dose of the heterologous Rickettsia that uniformly killed naïve mice. In contrast, heterologous immune sera did not protect mice against a lethal dose (two LD50) of rickettsiae in the mouse toxicity neutralization assay, the standard method for evaluation of rickettsial vaccine potency. These observations suggest that development of a broadly protective vaccine against spotted fever group (SFG) rickettsiae is feasible, and the results indicate that mouse toxicity neutralization is an inappropriate method for evaluation of candidate vaccines.

Animals↗
PubMed1994

Minimizing the risk of Q fever in the hospital setting.

Q fever is caused by a rickettsial microorganism (Coxiella burnetii) harboured in sheep. The highest concentration of organisms are found in birth products. It is a very contagious organism which humans can contract by inhaling aerosolized organisms. Most commonly it leads to an acute 'flu-like illness. Rarely, chronic disease with endocarditis is fatal. Infected patients should be treated with tetracyclines or chloramphenicol. A number of outbreaks have been reported in hospital and research settings. Because of the fear of patients and staff contracting Q fever, Hospital Research Review Boards have increasingly resisted the presence of sheep in medical facilities. The authors have reviewed the circumstances leading to these outbreaks and believe researchers can minimize the risk of Q fever. The most important precautions are to use sheep only from Q fever controlled flocks and, depending on the nature of the research, only male sheep.

Academies and Institutes↗