The results of screening more than 23,000 serum samples from persons belonging to risk groups, as well as those not belonging to such groups, in Moscow, Vilnius and Klaipeda are presented. Screening was carried out with the use of an assay system manufactured by the Scientific and Industrial Amalgamation "Antigen" (USSR). In this screening 3 HIV carriers were detected; of these, 2 were foreign students from two African countries.
Yupik Eskimos of southwestern Alaska have the highest known prevalence of hepatitis B virus infection of any general population in the United States. Prospective serological surveys of 1,280 seronegative Yupik Eskimos, performed between 1971 and 1976, identified 189 (14.8%) who developed serological evidence of hepatitis B virus infection. Twenty-six (13.8%) developed clinical hepatitis during the interval when seroconversion occurred. The proportion of patients with clinically apparent hepatitis increased with age (P less than .01), ranging from 9.5% of infections in patients who were four years of age or less to 33.3% of infections in patients who were 30 years of age or older. Twenty-five (13.3%) of the 188 individuals who were studied became chronic carriers of hepatitis B surface antigen. The risk of becoming a carrier was inversely related to the age of the patient at the time of infection (P = .02). Among patients who were four years of age or less when infected, 28.8% became chronic carriers of hepatitis B, as compared with 7.7% of those who were 30 years of age or older.
From: Fortuine, Robert et al. 1993. The Health of the Inuit of North America: A Bibliography from the Earliest Times through 1990. University of Alaska Anchorage. Citation number 1937.
Staphylococcus aureus nasal carriers risk autoinfection; however, knowledge about the factors that make specific strains successful colonizers is limited. This study was undertaken to identify the most successful S. aureus clones in nasal carriers and compare their distribution among host groups. The population structure of S. aureus isolates from healthy adults was investigated by spa typing 1,981 isolates from persistent and intermittent nasal carriers participating in a health survey. In the baseline screening (1,113 isolates), the most common spa types were t012 (8.4%), t084 (7.6%), and t065 (4.9%). Three large spa clonal complexes (spa CC012, spa CC065, and spa CC084) comprised 62.4% of the isolates. In multivariate models adjusted for age and smoking status, male sex was associated with higher risk for spa type t084 (odds ratio [OR], 1.72; 95% confidence interval [CI], 1.06 to 2.77), and lower risk of spa type t012 (OR, 0.60; 95% CI, 0.39 to 0.92) colonization. The prevalence of spa type t012 decreased significantly with increasing age (P = 0.03), with a prevalence almost twice as high in the youngest group (age 30 to 44 years, prevalence = 11.1%) as in the oldest group (age, 60 to 87 years; prevalence = 5.6%). Among baseline isolates, spa type t084 had a twofold-higher prevalence among intermittent carriers than among persistent carriers (10.6% versus 5.5%; P = 0.04). In summary, the two most prevalent spa types found in this study were significantly associated with age and/or gender. This may provide valuable clues to the multifactorial mechanisms, among them bacterial factors, involved in nasal colonization with S. aureus.
OBJECTIVE: To determine the total and functional serogroup C antibody response to a quadrivalent meningococcal polysaccharide vaccine in a group of aboriginal infants, children and adolescents. A secondary objective was to determine their prevalence of meningococcal carriage. DESIGN: Open prospective, before and after intervention study. SUBJECTS: Aboriginal children ages 0.5 to 19.9 years, living in a single Northern community and eligible for a public health immunization campaign conducted in all Manitoba native reserve communities to control a meningococcal serogroup C, electrophoretic type (ET) 15 outbreak. No outbreak cases had occurred in the community at the time of the study. METHODS: Total serogroup C capsular polysaccharide antibody (CPA) and functional bactericidal antibody (BA) responses were measured by enzyme-linked immunosorbent assay and bactericidal assay, respectively. RESULTS: Neisseria meningitidis was recovered from the oropharynx of 13 (5.2%) of 249 aboriginal children including 4 (1.6%) serogroup C isolates, all with the designation C:2a:P1.2,5 ET15. Paired sera from 152 children were available for assay. For CPA the geometric mean concentrations and proportions with > or =2 microg/ml before and after immunization were 0.69, 18% and 12.3, 96%, respectively. A significant increase in serum CPA was achieved by children of all ages, with the greatest response occurring after age 11 years. Among infants or =2 microg/ml. For BA the pre- and post-vaccine geometric mean titers were 1.02 and 45.9. The response was significantly associated with age. BA titers > or =1:8 were present, before and after immunization, respectively, in 0 and 0% of infants or =2-year-olds. CONCLUSION: The age-related total and functional group C meningococcal antibody response after quadrivalent polysaccharide vaccine among aboriginals is similar to that reported for Caucasian children. After age 2 all children made excellent CPA and BA responses. In the younger age groups the BA response was blunted but 82 to 95% achieved CPA titers of > or =2 microg/ml.
OBJECTIVE: Before 1991, Alaska Native children experienced one of the highest rates of invasive Haemophilus influenzae type b disease. H influenzae type b vaccine has led to a near-elimination of invasive H influenzae type b disease in the United States. We describe challenges encountered in controlling H influenzae type b disease in Alaska and update the current status of H influenzae disease and carriage in Alaska as lessons to other populations. PATIENTS AND METHODS: We reviewed data from statewide H influenzae disease surveillance conducted during 1980-2004. Vaccine coverage data were based on audits from tribal facilities and the National Immunization Survey. H influenzae type b colonization data were based on 6 carriage studies. RESULTS: After universal infant vaccination in 1991, H influenzae type b disease among Alaska Native and non-Native children
Ampicillin-resistant enterococci (ARE) have recently emerged as clinical pathogens in Sweden. Between 1991 and 1995 the incidence of ARE among enterococcal isolates at Uppsala University Hospital increased from 0.5% to 8.1%. Shedding of ARE from infected cases and risk factors for infection with ARE were studied during a period of 7 months for 38 ARE cases and 38 controls with ampicillin-susceptible enterococci. ARE cases had longer mean duration of hospitalization than controls (29 d vs. 15 d; p = 0.002). In univariate analysis other risk factors for infection with ARE were found to be prior therapy with > 2 antimicrobials (odds ratio [OR] 3.3; 95% confidence interval [CI] 1.2-9.5), > 4 weeks of antimicrobial therapy (OR 6.9; CI 1.8-28.3) and cephalosporin therapy (OR 9.1; CI 2.6-33.7). Fourteen of 26 skin carriers of ARE were found to be shedding ARE to the environment, compared to 2 of 12 non-skin carriers (p = 0.03). Pulsed-field gel electrophoresis suggested multifocal origin of the majority of the infecting ARE strains. Non-recognized fecal colonization and silent spread of ARE among many patients and over a prolonged time period is suggested to be the main explanation for the increase of ARE infections in our hospital. Infection control measures focusing on protecting patients at high risk for ARE infections and further efforts to optimize antimicrobial use are proposed.
A three-wave epidemic cycle caused by a new serotype agent is simulated. The mechanism of stepwise recession in a stratum of the susceptible persons is examined. A group of asymptomatic infected individuals as well as an antigen activity index, which regulates the intensity of input streams into the groups of infected patients, are introduced into the model. Morbidity rate is additionally regulated by the virulence. The model is identified according to the observations of the three-wave passage of Hong-Kong serotype (H3N2). On the basis of the simulation results it is shown that a leading role in upgrading the virulence capacity of the agent and in replenishment of the morbid group is assigned to the asymptomatic infected individuals.