ABSTRACT
BACKGROUND: To explore Bacillus Calmette-Guérin vaccine (BCG) as a protective factor against tuberculosis (TB) and how human immunodeficiency virus (HIV) infection modifies the effect of BCG on TB. METHODS: Two matched case-control studies were conducted. One study compared TB cases and controls who were HIV positive. The second compared TB cases and controls who were HIV negative. The study population consisted of 88 TB cases and 88 controls among HIV-positive individuals and 314 TB cases and 310 controls among HIV-negative individuals. Cases were new TB diagnoses, confirmed by either bacteriology, pathology, radiology or clinical response to treatment; controls were selected from people without TB symptoms and who sought medical attention in the same institution where a case was enrolled. BCG was assessed by the presence of a typical scar. RESULTS: The level of protection against all clinical forms of TB was 22% among HIV positive individuals (odds ratio [OR] = 0.78, 95% CI : 0.48-1.26) and 26% among HIV negatives (OR = 0.74, 95% CI : 0.52-1.05). There was a significant difference (P = 0.002) in the level of protection against extrapulmonary TB (ETB) between HIV-negative (OR = 0.54, 95% CI : 0.32-0.93) and HIV-positive individuals (OR = 1.36, 95% CI : 0.72-2.57). CONCLUSION: BCG has a modest protective effect against all forms of TB independent of HIV status, and BCG confers protection against extrapulmonary TB among HIV-negative individuals. However, HIV infection seems to abrogate the protective effect of BCG against extrapulmonary TB. Our data support the public health importance of BCG vaccine in the prevention of extrapulmonary TB among immunocompetent individuals.
Subject(s)
BCG Vaccine , HIV Infections/epidemiology , Tuberculosis/epidemiology , Tuberculosis/prevention & control , Adult , Case-Control Studies , Colombia/epidemiology , Comorbidity , Enzyme-Linked Immunosorbent Assay , Female , Humans , Logistic Models , Male , Odds Ratio , Socioeconomic Factors , Treatment OutcomeABSTRACT
The 16S rRNA sequences and selected phenotypic characteristics were determined for six recently isolated bacteria that can tolerate high levels of hydrolyzable and condensed tannins. Bacteria were isolated from the ruminal contents of animals in different geographic locations, including Sardinian sheep (Ovis aries), Honduran and Colombian goats (Capra hircus), white-tail deer (Odocoileus virginianus) from upstate New York, and Rocky Mountain elk (Cervus elaphus nelsoni) from Oregon. Nearly complete sequences of the small-subunit rRNA genes, which were obtained by PCR amplification, cloning, and sequencing, were used for phylogenetic characterization. Comparisons of the 16S rRNA of the six isolates showed that four of the isolates were members of the genus Streptococcus and were most closely related to ruminal strains of Streptococcus bovis and the recently described organism Streptococcus gallolyticus. One of the other isolates, a gram-positive rod, clustered with the clostridia in the low-G+C-content group of gram-positive bacteria. The sixth isolate, a gram-negative rod, was a member of the family Enterobacteriaceae in the gamma subdivision of the class Proteobacteria. None of the 16S rRNA sequences of the tannin-tolerant bacteria examined was identical to the sequence of any previously described microorganism or to the sequence of any of the other organisms examined in this study. Three phylogenetically distinct groups of ruminal bacteria were isolated from four species of ruminants in Europe, North America, and South America. The presence of tannin-tolerant bacteria is not restricted by climate, geography, or host animal, although attempts to isolate tannin-tolerant bacteria from cows on low-tannin diets failed.
Subject(s)
Clostridium/classification , Escherichia coli/classification , Hydrolyzable Tannins/metabolism , Phylogeny , RNA, Ribosomal, 16S/genetics , Rumen/microbiology , Streptococcus/classification , Yersinia/classification , Animals , Clostridium/genetics , Clostridium/isolation & purification , Colombia , DNA, Ribosomal/genetics , Deer , Erwinia/classification , Erwinia/genetics , Erwinia/isolation & purification , Escherichia coli/genetics , Escherichia coli/isolation & purification , Eubacterium/classification , Eubacterium/genetics , Eubacterium/isolation & purification , Goats , Honduras , Hydrolyzable Tannins/pharmacology , New York , Oregon , Peptostreptococcus/classification , Peptostreptococcus/genetics , Peptostreptococcus/isolation & purification , Phenotype , Sheep , Streptococcus/genetics , Streptococcus/isolation & purification , Yersinia/genetics , Yersinia/isolation & purificationABSTRACT
To define the role of adenoviruses in the pertussis syndrome, a study was done of a group of 134 children with clinical pertussis and a healthy control population of similar age, race, sex, and socioeconomic status. Adenovirus infections occurred in 30 (22.4%) of 134 patients with the pertussis syndrome and 5 (4.9%) of 101 control subjects (p smaller than 0.001). B. pertussis was recovered from 46 (34.3%) patients, and from 18 (39.1%) of these patients adenoviruses were also isolated. Although adenovirus infections also occurred in patients with the pertussis syndrome with negative cultures for B. pertussis, the rate, 12 of 88 patients (13.6%), was significantly lower (p smaller than 0.001). The clinical course was similar irrespective of the results of bacterial or viral cultures. These data substantiate the frequent association of adenoviruses with the pertussis syndrome, It would appear that adenoviruses do not usually have an independent role in the pathogenesis of the pertussis syndrome since we found them so commonly to be one agent in a mixed infection.