ABSTRACT
Nasal colonization plays an important role in the pathogenesis of Staphylococcus aureus infections. To identify characteristics associated with colonization, we studied a cross-section of a well-described cohort of HIV-seropositive and -seronegative active and former drug users considered at risk for staphylococcal infections. Sixty percent of the 217 subjects were Hispanic, 36% were women, 25% actively used injection drugs, 23% actively used inhalational drugs, 23% received antibiotics, and 35% were HIV-seropositive. Forty-one percent of subjects had positive nasal cultures for S. aureus. The antibiotic susceptibility patterns were similar to the local hospital's outpatient isolates and no dominant strain was identified by arbitrarily primed polymerase chain reaction (AB-PCR). Variables significantly and independently associated with colonization included antibiotic use (odds ratio [OR] = 0.37; confidence interval [CI] = 0.18-0.77), active inhalational drug use within the HIV-seropositive population (OR = 2.36; CI = 1.10-5.10) and female gender (OR = 1.97; CI = 1.09-3.57). Characteristics not independently associated included injection drug use, HIV status, and CD4 count. The association with active inhalational drug use, a novel finding, may reflect alterations in the integrity of the nasal mucosa. The lack of association between HIV infection and S. aureus colonization, which is contrary to most previous studies, could be explained by our rigorous control for confounding variables or by a limited statistical power due to the sample sizes.
Subject(s)
AIDS-Related Opportunistic Infections/microbiology , HIV Seronegativity , HIV Seropositivity/microbiology , Nasal Mucosa/microbiology , Staphylococcal Infections/microbiology , Staphylococcus aureus/growth & development , Substance-Related Disorders/microbiology , AIDS-Related Opportunistic Infections/drug therapy , AIDS-Related Opportunistic Infections/epidemiology , Adult , Cross-Sectional Studies , Female , HIV Seropositivity/epidemiology , Humans , Longitudinal Studies , Male , Microbial Sensitivity Tests , Middle Aged , Nasal Mucosa/drug effects , Prospective Studies , Rhinitis/epidemiology , Rhinitis/microbiology , Staphylococcal Infections/drug therapy , Staphylococcal Infections/epidemiology , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purification , Substance-Related Disorders/epidemiology , Substance-Related Disorders/virologyABSTRACT
IgA, IgG, IgM, and IgE levels in healthy, non-atopic, Israeli-born children aged 20 days to 16 years were analyzed and showed similar age-related values and dynamics as those of white populations found in other countries. No significant effect of sex of the individual or ethnic origin of the parents was found on the IgE values at different ages. This may indicate that total IgE levels are strongly influenced by environmental factors. Establishing tolerance limits at 97.5, 95, 75, 25 and 5th percentiles and the geometric mean provides the practitioner with more complete reference values. The use of multivariate control charts with tolerance limits from normal IgA, IgG, IgM, and IgE levels is described and is offered as an additional tool for the diagnosis of an allergic individual.