Infection rates of Amblyomma americanum and Dermacentor variabilis by Ehrlichia chaffeensis and Ehrlichia ewingii in southwest Missouri

Both Ehrlichia chaffeensis and Ehrlichia ewingii are causative agents of human ehrlichiosis. Both pathogens are transmitted to humans through the bite of an infected lone star tick (Amblyomma americanum). Since Missouri has a high incidence of human monocytic ehrlichiosis, we investigated the prevalence of E. chaffeensis- and E. ewingii-infected A. americanum and Dermacentor variabilis (American dog tick) ticks to help assess the relative risk for humans exposed to these vectors. We used a nested polymerase chain reaction assay for the detection of ehrlichial DNA in the collected ticks. Infection rates for both ehrlichial species were calculated from the assay results for each of the tick species. E. chaffeensis was found to be present in 9.8% of adult A. americanum ticks (57 of 579) and 6.7% of D. variabilis ticks (eight of 120). E. ewingii DNA was present at an infection rate of 5.4% in adult A. americanum (31 of 579) and 3.3% of D. variabilis ticks (four of 120). A minimum infection rate for nymph pools of A. americanum was 1.7% for E. chaffeensis and 0.6% for E. ewingii.     

13例HIV/HBV重叠感染患者的实验指标分析

目的了解艾滋病病毒与乙型肝炎病毒（HIV/HBV）重叠感染患者的临床特征,分析HIV与HBV在疾病进展中的相互作用。方法回顾性分析、比较13例HIV/HBV重叠感染组、28例单纯HIV感染组、28例单纯HBV感染组患者,在免疫功能、肝脏功能及血常规方面的差异。结果免疫功能检测：CD4^＋T细胞计数和CD4^＋/CD8^＋T细胞比值表现为HIV/HBV重叠感染组〈单纯HIV组〈单纯HBV组（P〈0.01）;肝脏功能检测：HIV/HBV重叠感染组与单纯HIV感染组各项指标无显著性差异,而单纯HBV组的丙氨酸氨基转移酶（ALT）、天冬氨酸转氨酶（AST）、总胆红素显著高于（P〈0.01）或高于（P〈0.05）另外两组;血常规检测：HIV/HBV重叠感染组和单纯HIV组各指标无显著性差异,但与单纯HBV组比较,则红细胞和血红蛋白显著降低（P〈0.01）,血小板明显升高（P〈0.01）。结论研究结果初步提示,HIV与HBV重叠感染后,可能减轻患者的肝细胞损伤,进一步降低患者的免疫功能。     

Causes of death in persons with human immunodeficiency virus infection.

PURPOSE: Pneumocystis carinii pneumonia (PCP) was reported to be the predominant cause of human immunodeficiency virus (HIV)-related deaths prior to 1988, the year that effective prophylaxis against PCP entered routine use. Our study was performed to study the causes of HIV-related death since January 1988 in a region where patient tracking is virtually complete. PATIENTS AND METHODS: We surveyed physicians associated with the Brown University Acquired Immunodeficiency Syndrome (AIDS) Program who cared for greater than 95% of known HIV-positive patients in Rhode Island. These physicians identified all those HIV-infected persons who had died under their care between January 1988 and July 1990, and determined these patients' causes of death by chart review. For comparison, death certificates of identified persons were also reviewed at the Rhode Island Department of Vital Statistics. RESULTS: Among 126 deaths since January 1988, bacterial infections were the most common cause of death (30%), whereas PCP was responsible for only 16% of deaths. Persons not receiving any form of PCP prophylaxis were more likely to die from PCP than were those who received prophylaxis (26% versus 11% [p = 0.04]). Cause of death as recorded on actual death certificates was imprecise, although bacterial infections were again the most common cause indicated. Only one death occurred in a patient with a CD4 count greater than 200/mL, and this was not HIV-related. CONCLUSION: PCP has not been the leading cause of death in our region since January 1988. Bacterial infections contribute substantially to mortality, and this may influence future prophylactic regimens. HIV-related deaths in patients with CD4 counts greater than 200/mL are unusual.     

Herpes simplex virus shedding and plasma human immunodeficiency virus RNA levels in coinfected women.

Asymptomatic herpes simplex virus (HSV) shedding was described in a cohort of human immunodeficiency virus (HIV)-infected women, and the association of HSV shedding with changes in plasma HIV RNA load was investigated. Genital, rectal, and oral swabs were obtained daily during a 4-week period for polymerase chain reaction and culture, and concomitant plasma specimens were drawn 3 times weekly for determination of HIV RNA load. During the study, 70% and 79% of subjects shed HSV from the oral cavity and genital area, respectively. Shedding of HSV occurred for a mean of 3.2 days for oral shedding and 5.4 days for genital shedding. Mean plasma HIV RNA loads during periods of HSV shedding and nonshedding and for periods 3 days after the cessation of shedding were compared; no significant differences were found (P=.74). In women who shed HSV, as evaluated by detection of virus, plasma HIV RNA load did not fluctuate with HSV shedding.     

Immunization for persons infected with human immunodeficiency virus

Immunization is an important measure to protect HIV-infected children and adults against certain vaccine preventable diseases. However, the antibody response, which is associated with the level of CD4+ T cell count, is frequently impaired in this group of patients. Certain vaccines enhance virus replication and transiently increase HIV viral load. Theoretically, vaccination should be given before the immune status of the patients is suppressed. Inactivated vaccines are generally safe and are beneficial for HIV-infected patients. These vaccines should be administered at appropriate age recommended for immunocompetent individuals. Live vaccines should be used with caution since some of the vaccines may be harmful to patients with severe immunologic suppression. Recommendations for immunization in HIV-infected patients may differ from country to country, depending on the availability and affordability of each vaccine, and the prevalence of each preventable disease. Vaccine trial in HIV-infected patients is needed in order to establish the most appropriate vaccine recommendation for this group of patients.     

Liver fibrosis progression in human immunodeficiency virus and hepatitis C virus coinfected patients. The Multivirc Group.

The natural history of hepatitis C virus (HCV) infection in human immunodeficiency virus (HIV)-infected patients has never been studied according to the concept of liver fibrosis progression. The aim of this work was to assess the fibrosis progression rate in HIV-HCV coinfected patients and in patients infected by HCV only. A cohort of 122 HIV-HCV coinfected patients was compared with a control group of 122 HIV-negative HCV-infected patients. Groups were matched according to age, sex, daily alcohol consumption, age at HCV infection, and duration and route of HCV infection. The fibrosis progression rate was defined as the ratio between fibrosis stage (METAVIR scoring system) and the HCV duration. The prevalence of extensive liver fibrosis (METAVIR fibrosis scores 2, 3, and 4) and moderate or severe activity were higher in HIV-infected patients (60% and 54%, respectively) than in control patients (47% and 30%, respectively; P <.05 and P <.001, respectively). The median fibrosis progression rate in coinfected patients and in control patients was 0.153 (95% confidence interval [CI], 0.117-0.181) and 0.106 (95% CI, 0.084-0.125) fibrosis units per year, respectively (P <.0001). HIV seropositivity (P <.0001), alcohol consumption (>50 g/d, P =.0002), age at HCV infection (<25 years old, P <.0001), and severe immunosuppression (CD4 count 50 g/d), CD4 count (相似文献   

查菲埃立克体和人单核细胞埃立克体病研究进展

埃立克体病是由埃立克体属微生物引起的一类人兽共患急性传染病,其特征为高热、头疼、贫血、白细胞减少、消瘦和黄疸等。查菲埃立克体是埃立克体属中代表性的蜱媒人畜共患病病原体,对人、畜均有较强致病性,在人体引起人单核细胞埃立克体病（HME）。本文较为全面地总结了查非埃立克体和HME的病原学、流行病学、临床表现、诊断和防治等方面的研究进展。     

Management of the coinfected patient: human immunodeficiency virus/hepatitis B and human immunodeficiency virus/hepatitis C

Deaths from liver disease have increased in persons infected with human immunodeficiency virus (HIV) because of coinfection with chronic hepatitis B and C; consequently, all HIV-infected patients should be screened for hepatitis B and C, and all those susceptible should be vaccinated for hepatitis B. Hepatitis A vaccination is indicated for susceptible coinfected patients. It is also important to stress other means of preventing the transmission of hepatitis, such as safe sex and avoidance of blood exposures. Three oral agents, lamivudine, adefovir, and tenofovir, are active against hepatitis B infection. The need for highly active antiretroviral therapy and hepatitis B therapy should be addressed in a coordinated fashion, since two of these agents are active against both HIV and hepatitis B virus. Oral combination therapy for hepatitis B infection looks promising but needs further study. Combination therapy for chronic hepatitis C with pegylated interferon plus ribavirin is the most effective available therapy and the current standard of care. Prior to therapy, patients should be evaluated for contraindications to therapy. During treatment, they should be closely monitored for adverse events.     

Relapses versus reinfections in patients coinfected with Leishmania infantum and human immunodeficiency virus type 1

In the Mediterranean basin, Leishmania infantum is a major opportunistic parasite in people with acquired immunodeficiency syndrome (AIDS), and up to 9% of the patients with AIDS suffer from newly acquired or reactivated visceral leishmaniasis. Distinguishing between reinfections and relapses in these patients is important because some apparent treatment failures occur in patients with new rather than reactivated infections. Isoenzyme characterization is limited for use in determining relapsed versus newly acquired leishmaniasis in human immunodeficiency virus (HIV)-infected patients because of the variability of L. infantum and the predominance of the MON-1 zymodeme in people coinfected with HIV. A seminested polymerase chain reaction (PCR) was used to amplify L. infantum minicircle kinetoplast DNA, and, after digestion, the restriction fragment-length polymorphism (RFLP) profiles showed that 3 (7.5%) of 40 patients coinfected with L. infantum and HIV had a new infection, whereas isoenzyme characterization indicated that all 40 patients had infection relapses. These results suggest the utility of this PCR-RFLP analysis in detecting leishmaniasis reinfection in HIV-positive patients.     

Selenium and interleukins in persons infected with human immunodeficiency virus type 1

An important role for selenium in human immunodeficiency virus (HIV) disease has been proposed. Decreased selenium levels, as found in persons with HIV infection or AIDS, are sensitive markers of disease progression. Selenium deficiency, an independent predictor of mortality in both HIV-1-infected adults and children, is an essential micronutrient that is associated with an improvement of T cell function and reduced apoptosis in animal models. In addition, adequate selenium may enhance resistance to infections through modulation of interleukin (IL) production and subsequently the Th1/Th2 response. Selenium supplementation up-regulates IL-2 and increases activation, proliferation, differentiation, and programmed cell death of T helper cells. Moreover, selenium supplementation may down-regulate the abnormally high levels of IL-8 and tumor necrosis factor-alpha observed in HIV disease, which has been associated with neurologic damage, Kaposi's sarcoma, wasting syndrome, and increased viral replication. Together, these findings suggest a new mechanism through which selenium may affect HIV-1 disease progression.     

Prophylaxis against opportunistic infections in persons infected with human immunodeficiency virus

This article outlines the current official recommendations for the prevention of opportunistic disease in adults and adolescents infected with human immunodeficiency virus, including specific guidelines for discontinuing primary and secondary prophylaxis when immune reconstitution has occurred as a result of highly active antiretroviral therapies. The recommendations, developed by the U. S. Public Health Service and the Infectious Diseases Society of America for clinicians and healthcare providers, were originally published in 1995 and revised in 1997, 1999, and 2002. The 2002 recommendations are summarized in this article.     

Usefulness of elastometry in evaluating the extents of liver fibrosis in hemophiliacs coinfected with hepatitis C virus and human immunodeficiency virus.

The newly developed elastometer, FibroScan((R)), was utilized to evaluate liver fibrosis in hepatitis C virus (HCV)- and human immunodeficiency virus (HIV)-coinfected 33 hemophiliacs and HIV-uninfected 24 patients with chronic hepatitis C. Chronicity in the liver was categorized into 4 stages by abdominal ultrasound (AUS): 1 (normal or fatty liver); 2 (chronic liver disease, mild); 3 (moderate); and 4 (severe). Stiffness of the liver was significantly increased as AUS stages advanced: 5.4+/-2.2 (N=3) versus 7.5+/-2.7 (N=9), in stage 1; 4.9+/-1.7 (N=2) versus 9.9+/-6.0 (N=10), in stage 2, 13.5+/-4.7 (N=5) versus 12.9+/-5.9 (N=6), in stage 3, and 22.0+/-9.5 (N=14) versus 28.1+/-21.3 (N=8), in stage 4, in non-HIV group and in HIV group, respectively (P=0.004 and 0.007). Stiffness was correlated with AUS stages (r=0.740, P<0.001), platelet counts (PLT; r=-0.642, P=0.001) and 7S domain of type IV collagen (IV-coll; r=0.480, P=0.024) in non-HIV group, while in HIV group, with IV-coll (r=0.801, P<0.001), AUS stages (r=-0.603, P<0.001), procollagen type III peptides (P-III-P; r=0.621, P=0.001), PLT (r=-0.480, P=0.005), and hyaluronic acid (r=0.433, P=0.027). FibroScan((R)) is absolutely noninvasive and can be the alternative to liver biopsy, especially in patients with bleeding tendency.     

Transfusion-acquired human immunodeficiency virus infection among immunocompromised persons

Transmission of the human immunodeficiency virus (HIV) was studied in a group of patients with cancer who received transfusion of blood components harvested from a single, asymptomatic, seropositive donor. Of ten living recipients, nine had antibodies to the virus in fresh or cryopreserved sera at a median of 384 days (range, 237 to 686) after transfusion. In three patients, an enzyme-linked immunosorbent assay was negative at the same time that Western blot and radioimmunoprecipitation techniques showed seropositivity. Cultures for HIV obtained at a median of 615 days (range, 322 to 714) after transfusion were positive in seven of nine seropositive recipients. Six seropositive recipients have developed immunologic and clinical sequelae of HIV infection at a median of 286 days (range, 56 to 745) after transfusion. The sera of the two patients without clinical sequelae neutralized HIV in an in-vitro assay, whereas the seven other seropositive patients lacked such neutralizing antibodies. Our study characterizes the clinical, serologic, virologic, and immunologic manifestations of HIV infection in immunocompromised persons.