Serosurvey of Coxiella burnetii in Descendants of Former Black Slaves (Quilombola Communities) of Southern Brazil.

Brazilian descendants of former Black-slave (quilombola) communities have been predisposed to several zoonotic diseases due to social vulnerability, characterized by subsistence and close contact with livestock and companion animals. Accordingly, the present study has assessed anti-Coxiella burnetii antibodies in 200 individuals and 20 dogs from four quilombola communities located in Paraná State, southern Brazil. Serum samples were tested by indirect immunofluorescence assay (IFA) using in-house and commercial diagnostic protocols, with analysis of seropositive titers and antibody type. Fisher's exact test was used to compare seropositivity to C. burnetti with binary variables, with variables with three or more possible responses submitted to logistic regression. In total, 44/200 (22%; 95% CI 16.82-28.24) people tested positive, and 4.5% had titers higher than 128, indicating a recent onset of C. burnetii infection. Seropositive individuals were statistically associated with the Limitão community (p = 0.0013), urban workers as occupations (p = 0.0475), consumption of undercooked meat (p = 0.0159), and contact with animal abortion (p = 0.0276). No seropositivity association was found for age, sex, education, habit of entering forest areas, consumption of game meat, consumption of raw milk, flea and tick bites, dog contact, or history of female miscarriage. Only one of 20 dogs was seropositive with a titer of 128, probably related to an acute animal infection. Despite the prevalence here being higher than previous Brazilian reports, including with symptomatic populations, the results were within range for worldwide outbreaks and occupational risk populations. To the reader's knowledge, this is the first human survey of Q fever in southern Brazil and should be considered a warning for C. burnetii in vulnerable populations, particularly Quilombola communities.

Seroprevalence estimate and risk factors for Coxiella burnetii infections among humans in a highly urbanised Brazilian state.

BACKGROUND: Q fever is among the top 13 global priority zoonoses, however, it is still neglected and under-reported in most of the world, including Brazil. Thus, we evaluated the seroprevalence of and the risk factors for Coxiella burnetii infections in humans from Minas Gerais, a highly urbanised Brazilian state. METHODS: Coxiella burnetii was searched for patient samples (n=437), which were suspected of then later confirmed as negative for dengue fever, by the indirect immunofluorescence technique and real-time PCR. Risk factors for infections and spatial clusters for both C. burnetii-seropositive individuals and livestock concentration were evaluated. RESULTS: We found that 21 samples (4.8%; 95% CI 3.0 to 7.2%) were reactive for at least one class of anti-C. burnetii antibodies (titer of ≥64), with rural residence (p=0.036) being a risk factor. Also, two spatial clusters of seropositivity were found within a significant area by Scan, and a probable relationship between the Scan result and the livestock concentration by area was found. CONCLUSIONS: Seropositive individuals were associated with rural residence, with a likely relationship with the livestock concentration. Thus, this study establishes baseline figures for C. burnetii seroprevalence in humans in a state of Brazil, allowing the monitoring of trends and setting of control targets, as well as more representative longitudinal and risk analysis studies.

Needlestick-Associated Rocky Mountain Spotted Fever, Brazil.

We report a fatal case of Rocky Mountain spotted fever (RMSF) in a man in Brazil without recent history of tick bites or environmental exposure. He received an accidental needlestick while working as a nurse. The nurse and his patient died. Both cases were confirmed as RMSF by molecular methods.

Confirming Rickettsia rickettsii as the etiological agent of lethal spotted fever group rickettsiosis in human patients from Espírito Santo state, Brazil.

Although Espírito Santo state is considered an endemic area for Brazilian spotted fever (BSF) with related lethal cases, it also constitutes the only state of southeastern Brazil that currently lacks a specific confirmation of the specific rickettsial agent. In an attempt to a species level confirmation of the etiological agent of fatal rickettsiosis cases in Espírito Santo state, in this study we tested human sera obtained between 2015 to 2017 by means of qPCR and subsequent conventional PCR protocols targeting gltA (citrate synthase) and ompA (190-kDA outer membrane protein) rickettsial genes. All samples were found to contain rickettsial DNA through the citrate synthase qPCR protocol. By conventional PCR, rickettsial gltA and ompA specific DNA fragments were detected in 25% (one sample) and 50% (2 samples) of the screened sera, respectively. Obtained consensuses for each gene partial sequences were 100% identical to Rickettsia rickettsii gltA and ompA genes. The present study confirms for the first time R. rickettsii as the etiological agent of a lethal spotted fever group rickettsiosis in human patients from Espírito Santo state.

Rickettsia rickettsii infecting Rhipicephalus sanguineus sensu lato (Latreille 1806), in high altitude atlantic forest fragments, Ceara State, Brazil.

In Brazil, Spotted Fever (SF) is caused by Rickettsia rickettsii and Rickettsia parkeri strain Atlantic Forest. In recent years, several human cases of a milder SF have been reported from the Maciço de Baturité region of Ceará State. Previous studies in this region found R. parkeri strain Atlantic Forest to be present in Rhipicephalus sanguineus sensu lato and Amblyomma ovale ticks. The present study isolated and identified the Rickettsia spp. present in this new endemic area in Brazil. In March 2015, R. sanguineus s.l. and A. ovale were collected in rural areas of the Maciço de Baturité region, and subjected to the isolation technique. A bacterium was isolated from one R. sanguineus s.l., which phylogenetic analysis clustered to the R. rickettsii group. In conclusion, R. rickettsii bacteria is circulating in the studied area and may in future have an impact on the clinical diagnoses and consequently cause changes in the profile of the disease in the region. In addition, we suggest the increase of epidemiological and environmental surveillance in the area, in order to prevent Brazilian Spotted Fever cases.