Antibody levels to recombinant tick calreticulin increase in humans after exposure to Ixodes scapularis (Say) and are correlated with tick engorgement indices.
The antibody responses of subjects who presented with a definite Ixodes scapularis (Say) tick bite were measured to determine the utility of the antibody response against recombinant tick calreticulin (rTC) as a biologic marker of tick exposure. Subjects bitten by I. scapularis evidenced an increase in anti-rTC antibody levels between visit 1 and visit 2 from 24.3 to 27.1 ng/microl serum (n = 88, p = 0.003), and levels remained elevated at visit 3 (p = 0.005). These anti-rTC antibody levels during visits 2 and 3 were significantly higher than those in four non-exposed controls. Tick engorgement indices, measured on the biting ticks, were found to be correlated with anti-rTC antibody levels (e.g., for visit 3: Pearson's r = 0.357, p = 0.001). Tick engorgement index (TEI), ratio of body length to scutal width, was identified to be the only independent predictor of anti-rTC antibody levels in linear regression models. Logistic regression revealed that a bite from an I. scapularis tick that became engorged (TEI >3.4) was a risk factor for anti-rTC antibody seropositivity (adjusted odds ratio for age and bite location = 7.4 (95% confidence interval 2.1-26.4)). The anti-rTC antibody test had a sensitivity of 0.50 and a specificity of 0.86 for a bite from I. scapularis that became engorged. Immunoblotting revealed that subjects made a specific anti-rTC antibody response. (+info)
Fulminant infection by uncommon organisms in animal bite wounds.
In 1995 and 1996, 215 patients exposed to different species of animals were treated at the Amarnath Polyclinic, Balasore, in India. Among them were two children infected by uncommon organisms, i.e., Capnocytophaga canimorsus and Pasteurella multocida; the patients recovered with appropriate antibiotic therapy. (+info)
Clinical course and risk factors of hepatitis C virus related liver disease in the general population: report from the Dionysos study.
BACKGROUND: The severity, clinical course, and risk of hepatitis C virus (HCV) related chronic liver disease are still rather poorly defined. AIMS: To investigate the prevalence, risk factors, and severity of HCV related liver disease in the general population, and investigate whether infection with a specific genotype is associated with an increased risk of cirrhosis or hepatocellular carcinoma. METHODS: HCV RNA determination by polymerase chain reaction (PCR) and HCV genotyping were performed in all anti-HCV positive subjects belonging to the Dionysos study (6917 subjects). Diagnosis of cirrhosis and hepatocellular carcinoma was established by liver biopsy in all cases. All the data were analysed by univariate and multivariate statistics in all the cohort. To investigate the natural history of HCV infection, anti-HCV positive subjects were followed up every six months for three years with liver function tests and ultrasonograms. RESULTS: The overall prevalence of HCV RNA positivity was 2.3%. Positivity increased progressively with age, and was higher in women (ratio of men to women = 0.7). Genotypes 1b and 2a were the most frequent (42 and 24% of HCV RNA positive patients), with a prevalence of 1 and 0.6% respectively. Intravenous drug use, blood transfusions received before 1990, history of previous hepatitis among the cohabiting, and history of animal (mainly dogs) bites were significantly (p<0.05) associated with HCV infection, independently of age and sex. Multivariate analysis showed that, independently of age, sex, and alcohol intake, genotype 1b infection, with or without coinfection with other genotypes, is the major risk factor associated with the presence of cirrhosis and/or hepatocellular carcinoma. During the three years of follow up, 57 (35%) of the HCV RNA positive subjects had consistently normal alanine aminotransferase and gamma-glutamyltransferase values. Two of the 22 HCV RNA positive cirrhotic patients, all drinking more than 90 g of alcohol a day, developed hepatocellular carcinoma (incidence rate = 3.0% per year). CONCLUSIONS: In the general population of Northern Italy, HCV infection is widespread, but only less than 50% of the anti-HCV positive subjects, particularly those infected with genotype 1b, are associated with a more severe liver disease. Alcohol consumption greater that 30 g a day significantly aggravates the natural course of the disease. (+info)
Characterization of Bacteroides forsythus strains from cat and dog bite wounds in humans and comparison with monkey and human oral strains.
Bacteroides forsythus strains recovered from cat and dog bite wound infections in humans (n = 3), monkey oral strains (n = 3), and the human oral ATCC 43037 type strain were characterized by using phenotypic characteristics, enzymatic tests, whole cell fatty acid analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, PCR fingerprinting, and 16S rDNA (genes coding for rRNA) sequencing. All three bite wound isolates grew on brucella agar supplemented with 5% sheep blood, vitamin K1, and hemin. These strains, unlike the ATCC strain and previously described monkey oral and human clinical strains, did not require N-acetylmuramic acid supplementation for growth as pure cultures. However, their phenotypic characteristics, except for catalase production, were similar to those of previously identified strains. PCR fingerprinting analysis showed differences in band patterns from the ATCC strain. Also, SDS-PAGE and whole cell fatty acid analysis indicated that the dog and cat bite wound strains were similar but not identical to the human B. forsythus ATCC 43037 type strain and the monkey oral strains. The rDNA sequence analysis indicated that the three bite wound isolates had 99.93% homology with each other and 98.9 and 99.22% homology with the human ATCC 43037 and monkey oral strains, respectively. These results suggest that there are host-specific variations within each group. (+info)
Human rabies postexposure prophylaxis during a raccoon rabies epizootic in New York, 1993 and 1994.
We describe the epidemiology of human rabies postexposure prophylaxis (PEP) in four upstate New York counties during the 1st and 2nd year of a raccoon rabies epizootic. We obtained data from records of 1,173 persons whose rabies PEP was reported to local health departments in 1993 and 1994. Mean annual PEP incidence rates were highest in rural counties, in summer, and in patients 10 to 14 and 35 to 44 years of age. PEP given after bites was primarily associated with unvaccinated dogs and cats, but most (70%) was not attributable to bites. Although pet vaccination and stray animal control, which target direct exposure, remain the cornerstones of human rabies prevention, the risk for rabies by the nonbite route (e. g., raccoon saliva on pet dogs' and cats' fur) should also be considered. (+info)
Risk for rabies transmission from encounters with bats, Colorado, 1977-1996.
To assess the risk for rabies transmission to humans by bats, we analyzed the prevalence of rabies in bats that encountered humans from 1977 to 1996 and characterized the bat-human encounters. Rabies was diagnosed in 685 (15%) of 4,470 bats tested. The prevalence of rabies in bats that bit humans was 2.1 times higher than in bats that did not bite humans. At least a third of the encounters were preventable. (+info)
Update on the status of Africanized honey bees in the western states.
The Africanized honey bee (AHB), Apis mellifera scutella--perhaps better known as the "killer bee"--has arrived in the western United States and in southern California, following a nearly 50-year north-ward migration across South and Central America. First detected near Hidalgo, Texas in October 1993, the bees continue to advance 100 to 300 miles per year by colonizing existing hives or forming new hives in the wild. Although the AHB's "killer" reputation has been greatly exaggerated, the presence of AHBs will increase the chances of people being stung. (+info)
Linezolid activity compared to those of selected macrolides and other agents against aerobic and anaerobic pathogens isolated from soft tissue bite infections in humans.
Linezolid was tested against 420 aerobes and anaerobes, including 148 Pasteurella isolates, by an agar dilution method. Linezolid was active against all Pasteurella multocida subsp. multocida and P. multocida subsp. septica isolates and most Pasteurella canis, Pasteurella dagmatis, and Pasteurella stomatis isolates. The MIC was +info)