No abstract

No abstract

No abstract

In Brazil, Brazilian spotted fever was once considered the only tick-borne rickettsial disease. We report eschar-associated rickettsial disease that occurred after a tick bite. The etiologic agent is most related to Rickettsia parkeri, R. africae, and R. sibirica and probably widely distributed from São Paulo to Bahia in the Atlantic Forest.

Leptospirosis is a widespread anthropozoonosis, with a broad array of mammalian reservoirs, occurring as rural endemics, urban outbreaks related to floods, and emergent disease associated with water sports and recreational exposure in developed countries. Rats are the major source of human infection, particularly in urban areas; however few reports have focused on the pathology of leptospirosis in this host. This study reports pathological changes in 60 kidneys from captured wild rats and compares these with changes in the kidney of Wistar rats experimentally infected with Leptospira interrogans serovar Copenhageni strain FIOCRUZ L1-130. A broad range of morphological alterations were detected in the kidneys from captured rats but interstitial nephritis was the only feature reproduced under experimental conditions. The role of interstitial nephritis in the pathogenesis of leptospirosis is reviewed and it is suggested that rats may provide a potential tool for the study of colonization mechanisms and host resistance in acute leptospiral disease.

It is possible that biological behavior of KOTs may be related to suprabasal proliferative compartment in the cystic epithelium as observed by high levels of Ki-67, p53 and p63. In addition, p63 immunostaining may represent immaturity of keratinocytes in KOTs, and suggests that this protein may participate in the regulation of epithelial cell differentiation. Taken together, these data may favor tumorigenesis on KOTs.

eThe pathogen Leptospira interrogans is a highly motile spirochete that causes acute and fulminant infections in humans and other accidental hosts. Hematogenous dissemination is important for infection by the pathogen but remains poorly understood because few animal model studies have used sensitive tools to quantify the bacteria. We evaluated the kinetics of leptospiral infection in Golden Syrian hamsters by a sensitive quantitative real-time PCR (TaqMan) with lipl32 as the target gene. The dissemination and bacterial burden were measured after intraperitoneal infection with a high dose (10 8 ) or low dose (2.5 ؋ 10 2 ) of leptospires. We also examined the conjunctival challenge route to mimic the natural history of infection. Quantification of leptospires in perfused animals revealed that pathogens were detected in all organs of intraperitoneally infected hamsters, including the eye and brain, within 1 h after inoculation of 10 8 virulent L. interrogans bacteria. Peaks of 10 5 to 10 8 leptospires per gram or per milliliter were achieved in blood and all tissues between day 4 and day 8 after intraperitoneal inoculation of highand low-dose challenges, respectively, coinciding with macroscopic and histological changes. The conjunctival route resulted in a delay in the time to peak organ burden in comparison to intraperitoneal infection, indicating that although infection could be established, penetration efficiency was low across this epithelial barrier. Surprisingly, infection with a large inoculum of highpassage-number attenuated L. interrogans strains resulted in dissemination to all organs in the first 4 days postinfection, albeit with a lower burden, followed by clearance from the blood and organs 7 days postinfection and survival of all animals. These results demonstrate that leptospiral dissemination and tissue invasion occur. In contrast, development of a critical level of tissue burden and pathology are dependent on the virulence of the infecting strain.

A cohort of children attending a day care center in Salvador (Bahia, Brazil) was studied prospectively to determine the incidence of viral respiratory infectious episodes and to identify the viruses associated with them. Two hundred seventy-one nasopharyngeal samples were collected over a 1-year period for examination, using indirect immunofluorescence with monoclonal antibodies against adenovirus, influenza A and B, parainfluenzae 1-3, and respiratory syncytial virus, and reverse transcriptase-polymerase chain reaction for picornavirus. Examination yielded positive results in 116 samples (42.8%). Rhinovirus was identified alone in 56 samples (48.3%) and was observed along with other viruses in 11 additional samples. Incidence density of viral respiratory infectious episodes was 7.66 episodes/1,000 child-days.