Reviews of infectious diseases最新文献

Pyomyositis is a pyogenic infection of skeletal muscle that is endemic in the tropics and is being recognized with increasing frequency in temperate climates. We report two cases of nonendemic pyomyositis in patients with diabetes mellitus. A review of the literature suggests that diabetes mellitus may be an important risk factor for the development of pyomyositis. Possible mechanisms of this association are discussed.

Antimicrobial agents given as prophylaxis have profound effects on the microbial flora of the skin. Coagulase-negative staphylococci cultured from the skin of patients after cardiac surgery have been found to be more resistant to antimicrobial drugs than organisms cultured from the same skin sites preoperatively. Evidence exists both for the selection of resistant organisms from the preoperative flora and for the postoperative acquisition of such organisms from the nosocomial environment. Staphylococci causing postoperative infections have the same antimicrobial resistance phenotypes as do colonizing isolates; this observation suggests that colonized patients and hospital staff make up a nosocomial reservoir for resistant organisms.

A case of hypothyroidism that manifested as depression and deteriorating functional status and that ultimately resulted in the death of a 41-year-old patient with AIDS is described. Postmortem examination revealed destruction of the thyroid gland by Kaposi's sarcoma. Analysis of stored serum samples revealed that the patient had become profoundly hypothyroid during his terminal illness. Practitioners are reminded of the need to exclude metabolic causes when treating encephalopathy in patients infected with human immunodeficiency virus.

This report summarizes the findings of the 17 published studies involving humans who have been experimentally infected with filarial parasites. Over the past 60 years, 45 individuals have been deliberately infected with Wuchereria bancrofti, Brugia malayi, Brugia pahangi, Loa loa, Mansonella perstans, Mansonella ozzardi, and/or Onchocerca volvulus. The findings from these experimental infections of humans have helped define microfilarial survival and periodicity within human hosts, the prepatent period for the causative agents of lymphatic filariasis, etiologic agents for particular clinical syndromes, immunologic and hematologic consequences of filarial infection, and the role of chemotherapeutic agents in the prevention and treatment of filarial infections.

More than four decades ago, Rickettsia australis was discovered to be the etiologic agent of Queensland tick typhus (QTT), yet many unanswered questions persist about the ecology, epidemiology, and clinical features of this disease. We review 46 previously published cases of QTT along with 16 cases discovered by active surveillance. QTT is usually a mild disease. Patients often have regional lymphadenopathy and eschars. Some have vesicular rashes. Because clinical features overlap, serologic tests are necessary to distinguish QTT from other endemic Australian rickettsial diseases (scrub and murine typhus). Only two tick vectors of R. australis have been identified: Ixodes holocyclus and Ixodes tasmani. Until rickettsiae are isolated from patients in Victoria and Tasmania, it remains unproven that spotted fever group infections in these locations are due to R. australis. However, available serologic, epidemiologic, and clinical data suggest that QTT is not confined to the area in which R. australis was first isolated (Queensland); rather, it occurs along a 3,200-km span of eastern coastal Australia, from tropical to temperate climates.

Although rates of seroconversion following administration of trivalent oral poliovirus vaccine (TOPV) approach 100% in industrialized countries, only 73% (range, 36%-99%) and 70% (range, 40%-99%) of children in developing countries have detectable antibody to poliovirus types 1 and 3, respectively, after three doses. While factors accounting for these differences have not been fully elucidated, available data suggest that type 2 vaccine virus and enteric pathogens often interfere with responses to types 1 and 3 vaccine viruses but that this interference may be overcome by modifying the absolute and relative dosage of the three Sabin types. Increasing the interval between doses beyond 30 days may also be important, in view of the prolonged excretion of vaccine virus and the potential for interference with responses to subsequent doses. Although advances in molecular biology may ultimately lead to the development of more-immunogenic vaccine candidates, approaches such as increasing the number of doses of TOPV, mass vaccination campaigns, and combined use of oral and inactivated vaccines should also be considered.

The patterns of use of perioperative antimicrobial prophylaxis were assessed in a randomly selected sample of short-stay hospitals in middle Tennessee. Overall, 438 procedures (48%) were associated with antimicrobial prophylaxis. Prophylaxis was more common in hospitals with more than 400 beds than in smaller hospitals. Moreover, prophylactic antibiotics were given more often for procedures with a proven indication for prophylaxis than for those without a proven indication (60% vs. 41%, P less than .05); this relationship remained constant regardless of hospital size (common odds ratio, 2.09). However, prophylaxis for procedures with a proven indication was more likely to be given in teaching hospitals than in nonteaching hospitals (odds ratios, 5.41 vs. 1.94). The duration of prophylaxis was less than 2 days for 89% of procedures. A wide variety of agents were used. This study suggests that while improvements have been made over the past decade in decisions about the duration of prophylaxis, considerable variation remains in the selection of the procedures in which such treatment is administered and of the antimicrobial agents used.

Typhoid accounts for 8% of pediatric admissions to the Aga Khan University Hospital in Karachi, Pakistan. Over a 4-year period (1986-1989), 355 children had typhoid documented by culture of blood or bone marrow. Strains of Salmonella, resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole accounted for 20% of these cases. Compared with children infected by drug-susceptible strains of Salmonella, children with multiresistant infection were generally sicker at presentation and were more likely to be assessed as appearing "toxic" (P less than .001), as having disseminated intravascular coagulation (P less than .01), and as exhibiting hepatomegaly (P less than .01). The mortality was 4.2% among children with multiresistant infection and 1.4% among those infected with strains susceptible to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole; the higher mortality in the former group was probably due to a longer duration of illness (P less than .05) and to ineffectual oral antimicrobial therapy before hospitalization.