Reviews of infectious diseases最新文献

Streptococcus pneumoniae is an uncommon cause of infection in the female genital tract. An unusual case of postmenopausal pneumococcal tubo-ovarian abscess is presented. The pathogenesis of this infection probably entailed the ascent of bacteria from the vagina to the internal genitalia; there was no evidence of infection of the bloodstream or gastrointestinal tract.

This review covers four areas: the use of prophylactic antibiotics in orthopedic surgery not involving prosthetic devices; the use of prophylactic antibiotics in prosthetic joint implantation; the use of antibiotic-containing cement in prosthetic joint surgery; and the use of prophylactic antibiotics for dental procedures in individuals with implanted prosthetic joints. The major conclusions are as follows: (1) Prophylactic antimicrobial agents lower the rate of wound infection following surgery for closed hip fractures. (2) Antimicrobial prophylaxis reduces the frequency of deep wound infection following total joint replacement; operating rooms with ultraclean air have a similar effect. (3) Antibiotic-impregnated cement is as effective as systemic antibiotics in preventing early infection following total joint replacement. (4) For routine dental work in most patients with total joint replacement, there is insufficient evidence to support antibiotic prophylaxis; for such individuals with periodontal disease or potential dental infection, antimicrobial prophylaxis seems indicated.

An excess rate of mediastinitis complicating cardiac operations occurred in one of two hospitals served by the same surgeons. The rates were 4% at hospital A and 0.48% at hospital B for the same period (P = .002). At hospital A five patients who underwent a thoracic reoperation experienced postoperative pneumonia or bacteremia prior to onset of mediastinitis; these infections were caused by the same bacterial species. This circumstance provided a unique opportunity for comparing infection control practices, in which one hospital served as a control for interventional changes. At hospital A regular and temporary critical care nursing personnel, who took care of both infected and uninfected patients, did not antisepticize their hands before manipulation of percutaneous catheters. After cohorts of nurses were formed and antisepsis of the hands with alcohol was strictly enforced (no diminution in the number of temporary personnel was instituted), the frequency of mediastinitis decreased significantly among patients who underwent reoperations at hospital A (P = .002), but no concurrent change was noted at hospital B. Preventable postoperative remote-site infection may lead to mediastinitis.

Clinical experience over the past decade suggests that the number of cases of polymicrobial infective endocarditis has greatly increased. We found 101 reports of cases of polymicrobial endocardial infection in a review of the English-language literature published in the 1980s. The mean patient age, 36.5 years, reflected a relatively young population, with men outnumbering women almost 2:1. Seventy-one patients were intravenous drug users; only three described recent invasive medical procedures. More than one-half of the patients had infections of the tricuspid valve, and 31 patients developed septic pulmonary emboli. The mean age of patients who died was significantly (P = .004) greater than that of those who survived. In comparison with patients who were infected with three or more organisms, those who were infected with two pathogens were almost twice (38.3% vs. 20.8%) as likely to die of their infections. These differences in mortality reflected the relative paucity of endocardial infections involving the left heart in patients with polymicrobial infections caused by three or more organisms (compared with those infected with two pathogens, P = .0032) and the variability in virulence among infecting agents.

Although the studies presented in this symposium illustrate the benefits of biologicals in treating patients whose immune systems have been compromised by congenital or acquired immunodeficiencies, it is likely that in the future these agents will also play a role in the management of immunocompetent persons suffering from complications of infection. The insights resulting from the work discussed here provide a strong basis for making that possibility a reality.

Neisseria mucosa is a species of gram-negative cocci that has a characteristic mucoid, adherent colonial morphology and includes pigmented and nonpigmented morphotypes. The ability of N. mucosa to reduce nitrates distinguishes it from other Neisseria species. N. mucosa is part of the normal human nasopharyngeal flora and infrequently causes human infections, including meningitis. We report a unique case of a patient with a cerebrospinal fluid shunt infection due to N. mucosa and review five other reports of cases of meningitis caused by this organism. Seven additional previously reported cases of presumed N. mucosa meningitis have been excluded from this review on the basis of the current criteria for identification of the organism. In the reports of established cases, female infants and children who often had predisposing conditions predominate. Although the outcome for such patients has been favorable, no clinical or laboratory findings are helpful in distinguishing meningitis due to N. mucosa from that due to other bacteria.

Four cases of blastomycosis seen in two acute care hospitals in Harare, Zimbabwe, are described. All patients had symptoms of at least 2 months' duration before presentation, and all had radiographic evidence of pulmonary consolidation. Three patients had confirmed bone involvement, and two had chronic discharging sinuses. The features of blastomycosis in Africa are reviewed, and problems of diagnosis and treatment are discussed. It is concluded that blastomycosis in Africa may often be misdiagnosed as tuberculosis or pyogenic infection in the absence of adequate facilities for mycologic investigation.

We reviewed 103 episodes of bacteremia in 93 patients with spinal cord injury who had bacteremia during initial hospitalization (39 patients) or readmission (54 patients) during 1978-1988. Eighteen episodes (18%) were due to polymicrobial infections. Urinary tract infections (47%), infected pressure areas (19%), and pneumonia (9%) were the most frequent primary infections and sources of the bacteremia. The bacteria most frequently associated with urinary tract infections were enterococci (26%), Escherichia coli (26%), Pseudomonas species (20%), and Klebsiella pneumoniae (12%). Bacteria most frequently isolated from patients with infected pressure areas were anaerobes and Staphylococcus aureus. Bacteremia was the cause of death for 8 patients (9%). The urinary tract was identified only once as the source of gram-negative bacteremia in an immunocompetent patient who died. The reason for the low mortality in patients with spinal cord injury is unclear.

In the summer and fall of 1988, three humans and one dog in a lakeshore community in northern Wisconsin were found to have blastomycosis on the basis of the results of cultures and histologic studies; the infection was also suspected in one human and four dogs on the basis of clinical data. Serologic testing with use of enzyme immunoassay for antibody to the A antigen of Blastomyces dermatitidis was performed for 77 additional human residents and visitors in the area an average of 9 months after the outbreak. Titers of antibody of greater than or equal to 1:32 were considered presumptive evidence of blastomycosis, and measurement of such titers enabled identification of 18 additional suspected cases in this group, compared with none in a control group (n = 40). Of the 22 humans with confirmed and suspected cases, 16 (73%) were asymptomatic. Epidemiologic and meteorologic data gathered during this period suggested an associated between this outbreak and the presence of dust from excavation for a hotel across the lake. The result of this study further confirm the common occurrence of self-limited and subclinical infection with B. dermatitidis and suggest that excavation in an area endemic for B. dermatitidis is a risk factor for human and canine infection.