临床医师处方抗菌药物前需思考的几个问题

2001年和2003年卫生部全国医院感染监测网调查结果均显示,医院横断面抗菌药物的平均使用率在54%以上,联合用药较为普遍.国内监测结果也表明细菌耐药性日益严重.针对上述问题,提出临床医师在面对病人开处方抗菌药物之前,须思考的问题:是否有使用抗菌药物的适用症?是否了解选用的抗菌药物,选用何种药物?是否有联合使用抗菌药物的指征?采用何种给药途径、给药剂量、给药时间?是否属于特殊宿主或针对特殊病原体的感染使用抗菌药物?密切观察抗菌药物治疗是否有效?针对局部感染是否需要穿刺或外科手术引流病灶?是否已出现抗菌药物的不良反应?是否存在药物相互作用?是否存在不合理使用抗菌药物情况?并且针对每个问题提出了建议.     

Pneumocystis carinii pneumonia recurrence in HIV patients on highly active antiretroviral therapy: secondary prophylaxis

The incidence and risk factors for Pneumocystis carinii pneumonia (PCP) recurrence were evaluated in 451 HIV-infected patients enrolled in the French Hospital Database on HIV who started highly active antiretroviral therapy (HAART) while receiving secondary PCP prophylaxis after a first episode occurring between January 1995 and December 1998. There were 18 episodes of recurrent PCP. On HAART, the CD4+ cell count increased to above 200 x 106/L in 274 patients, 51 of whom stopped PCP prophylaxis. None of these patients had PCP recurrences during 363 person-years (PY) of follow-up after the CD4+ cell count had reached 200 x 106/L (incidence rate [IR], 0.00 cases/100 PY; 95% confidence interval [CI], 0.00-0.82), and 37 PY of follow-up after the CD4+ cell count had reached 200 x 106/L and PCP prophylaxis had been discontinued (IR, 0.00 cases/100 PY; 95% CI, 0.00-7.84). The CD4+ cell count remained < 200 x 106/L in 177 patients; 9 patients stopped PCP prophylaxis, and 6 of these had a disease recurrence. Multivariate Cox analysis (time censored when CD4+ cell count > 200 x 106/L) showed that discontinuation of secondary prophylaxis (relative hazard [RH], 25.95; p <.0001) was associated with recurrence, whereas higher CD4+ cell counts during follow-up (RH, 0.39/50 x 106/L increment; p <.002) were protective.     

Extended epidemic of nosocomial urinary tract infections caused by Serratia marcescens

In recent years a significant increase in the incidence of Serratia marcescens infections was noted at the Chang Gung Memorial Hospital, Taoyuan, Taiwan. A review of laboratory (1991 to 2002) and infection control (1995 to 2002) records showed the possibility of an extended epidemic of nosocomial urinary tract infections (UTIs) caused by S. marcescens. Therefore, in 1998 and 1999, 87 isolates were collected from patients with such infections and examined and another 51 isolates were collected in 2001 and 2002. The patients were mostly elderly or the infections were associated with the use of several invasive devices. S. marcescens was usually the only pathogen found in urine cultures in our study. Neither prior infections nor disseminated infections with the organism were observed in these patients. Resistance to most antibiotics except imipenem was noted. Two genotyping methods, pulsed-field gel electrophoresis and infrequent-restriction-site PCR, were used to examine the isolates. A total of 12 genotypes were identified, and 2 predominant genotypes were found in 72 (82.8%) of the 87 isolates derived from all over the hospital. However, 63.9% of the isolates of the two genotypes were from neurology wards. A subsequent intervention by infection control personnel reduced the infection rate greatly. The number and proportion of the two predominant genotypes were significantly reduced among the 51 isolates collected in 2001 and 2002. Thus, a chronic and long-lasting epidemic of nosocomial UTIs caused by S. marcescens was identified and a successful intervention was carried out. Both a cautious review of laboratory and infection control data and an efficient genotyping system are necessary to identify such a cryptic epidemic and further contribute to the quality of patient care.     

HIV-1 p24 antigen is a significant inverse correlate of CD4 T-cell change in patients with suppressed viremia under long-term antiretroviral therapy

An HIV-1 p24 antigen test involving signal amplification-boosted ELISA of heat-denatured plasma was evaluated prospectively in 55 patients whose viral RNA in plasma had previously been suppressed for at least 6 months under antiretroviral combination therapy. During a median follow-up of 504 days, CD4 counts increased by a median of 62 cells per year. By univariate and multivariate linear regression analysis, the level of p24 antigen as expressed by the absorbance/cutoff ratio was a significant inverse correlate of both the CD4 count in a sample (p =.013) and its annual change in a patient (p <.0001). The p24 antigen retained significance even among 48 individuals whose HIV-1 RNA, apart from occasional blips, remained below 400 copies/mL. Batch-wise retesting of 70 samples from 5 such patients with a further improved procedure showed measurable p24 antigen in all but 1 sample and an inverse correlation with both the CD4 count (p =.0331) and percentage (p <.0001), thus confirming the prospectively generated data. Comparison of p24 antigen and HIV-1 RNA concentrations indicate that the p24 antigen detected in these samples is not associated with viral RNA-containing particles and may originate from other compartments of virus expression.     

Longitudinal analysis of B cell repertoire and antibody gene rearrangements during early HIV infection

In chronically HIV infected individuals, a number of functional B cell abnormalities have been described. However, the immediate changes that occur in the B cell compartment following viral exposure and how they affect the long-term course of infection are not well understood. We report the longitudinal analysis of B cell repertoires during early infection in untreated and treated individuals receiving highly active antiretroviral therapy (HAART). Analysis was based on IgG heavy chain gene utilization and CDR3 length measurement and relationship with CD4/CD8 counts, viral load, and total serum IgG, and anti-HIV antibodies levels. Repertoires were assessed at baseline and at weeks 2, 4, 12, 24, and 72 after initiation of therapy. The findings indicate a stable peripheral B cell repertoire during the first 72 weeks following infection, particularly in the HAART treated patients. A modest association between B cell repertoire integrity and viremia levels as well as treatment was detected.     

Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 28-2001. A 44-year-old woman with chills, fever, jaundice, and hepatic abscesses

BACKGROUND: The introduction of expensive but very effective antiviral medications has led to questions about the effects on the total use of resources for the care of patients with human immunodeficiency virus (HIV) infection. We examined expenditures for the care of HIV-infected patients since the introduction of highly active antiretroviral therapy. METHODS: We interviewed a random sample of 2864 patients who were representative of all American adults receiving care for HIV infection in early 1996, and followed them for up to 36 months. We estimated the average expenditure per patient per month on the basis of self-reported information about care received. RESULTS: The mean expenditure was $1,792 per patient per month at base line, but it declined to $1,359 for survivors in 1997, since the increases in pharmaceutical expenditures were smaller than the reductions in hospital costs. Use of highly active antiretroviral therapy was independently associated with a reduction in expenditures. After adjustments for the interview date, clinical status, and deaths, the estimated annual expenditure declined from $20,300 per patient in 1996 to $18,300 in 1998. Expenditures among subgroups of patients varied by a factor of as much as three. Pharmaceutical costs were lowest and hospital costs highest among underserved groups, including blacks, women, and patients without private insurance. CONCLUSIONS: The total cost of care for adults with HIV infection has declined since the introduction of highly active antiretroviral therapy. Expenditures have increased for medications but have declined for other services. However, there are large variations in expenditures across subgroups of patients.     

Incidence of and risk factors for lipoatrophy (abnormal fat loss) in ambulatory HIV-1-infected patients

To identify clinical factors associated with the incidence of HIV-1-associated lipoatrophy, HIV-1-infected patients in the HIV Outpatient Study (HOPS) were prospectively evaluated for clinical signs of lipoatrophy at two visits about 21 months apart. Development of lipoatrophy was analyzed in stratified and multivariate analyses for its relationship to immunologic, virologic, clinical, and drug treatment information for each patient. Of 337 patients with no lipoatrophy at Survey 1, 44 (13.1%) developed moderate or severe lipoatrophy between the two surveys. In multivariate analyses, significant risk factors for incident lipoatrophy were white race (OR = 5.2; 95% CI: 1.9-17.1; =.003), CD4 T-lymphocyte count at Survey 2 less than 100 cells/mm3 (OR = 4.2; 95% CI: 1.3-13.1; =.013), and body mass index (BMI) less than 24 kg/m2 (OR = 2.4; 95% CI: 1.1-5.4; =.024). Analyses that controlled for the severity of HIV illness demonstrated no significant association with use of or time on any antiretroviral agent or class of agents and the development of lipoatrophy. Some host factors and factors associated with previous or current severity of HIV infection, especially CD4 T-lymphocyte cell count, appeared to have the strongest association with incidence of lipoatrophy.     

A组轮状病毒广州地方株VP7基因序列的比较分析

目的 了解我国轮状病毒G1型广州地方株与标准株及北京G1型地方株VP7基因序列的差异，为我国轮状病毒疫苗的研制提供资料。方法 通过逆转录—聚合酶链反应(RT—PCR)获得了轮状病毒广州地方株R97—196 VP7全基因的cDNA片段，将其克隆入T—A克隆质粒pUCm—T中，构建成重组质粒pUCmT—VP7，对克隆的VP7基因进行序列测定。结果 该地方株的基因核苷酸全长为1062nt，读码框架和以往的研究一致，和北京G1型地方株173的VP7氨基酸序列具有高度同源性(98％)，而与不同血清型标准株间则变异较大(73％—81％)，氨基酸序列中存在的一些高变区和保守功能区与已报道的研究结果一致。从进化角度分析，与轮状病毒标准株Wa株，相距较远。结论 轮状病毒广州地方株R97—196 VP7基因片段属G1型，轮状病毒VP7基因的变异与地域有一定关系。     

Increasing trend of Cesarean deliveries in HIV-infected women in the United States from 1994 to 2000

BACKGROUND: Meta-analysis and randomized clinical trial results reported in June 1998 indicated a significant reduction in perinatal HIV transmission rates among mothers undergoing a cesarean section (C-section). OBJECTIVE: The objective of this study was to examine recent trends in and factors associated with C-section deliveries among HIV-infected women in the United States. DESIGN: A multisite pediatric medical record review of a cohort of HIV-exposed and HIV-infected infants in the Pediatric Spectrum of HIV Disease (PSD) Cohort study (n = 6467) and the national Pediatric HIV/AIDS Reporting System (HARS) (n = 8,306) was conducted. SETTING/PATIENTS: All infants born between 1994 and 2000 to HIV-positive mothers referred to the PSD study or to a Pediatric HARS hospital or clinic site were enrolled. RESULTS: The proportion of deliveries by C-section was steady at about 20% from 1994 through June 1998. From July 1998 through December 2000, this proportion increased to 44% in the PSD study and to nearly 50% in the Pediatric HARS. On analysis by multiple logistic regression, delivery of infants by C-section was associated with the release of study results (OR = 2.83), delivery in four PSD sites in reference to Texas (OR: 2.02-1.43), having private medical care reimbursement (OR = 1.62), and having maternal prenatal care (OR = 1.43). CONCLUSIONS: The PSD and Pediatric HARS data demonstrate a sharp increase in C-section rates mainly among HIV-infected women in the United States after the release of the meta-analysis and randomized clinical trial results in 1998. This finding highlights the rapid impact of study results on obstetric practice. It underscores the critical role of prenatal care in offering perinatal interventions such as scheduled C-section when indicated to reduce the likelihood of HIV transmission.