Scandinavian journal of infectious diseases. Supplementum最新文献

Nasopharyngeal and throat swabs taken from 66 patients presenting at the Department of Infectious Disease with symptoms of upper and lower respiratory tract infection were analysed by use of the polymerase chain reaction (PCR) for Chlamydia pneumoniae and Mycoplasma pneumoniae. A total of 18 patients (27%) were positive by PCR for C. pneumoniae. All 18 patients were positive from throat swabs, and three were also positive from nasopharyngeal specimens. The difference between the outcome of PCR using throat and nasopharyngeal swabs was statistically significant. A total of 7 patients (10.6%) were positive for M. pneumoniae and of these, 6 were positive from throat swabs and 2 were positive from nasopharyngeal swabs. This difference was not statistically significant, probably due to the low numbers of positive patient specimens.

To increase the accessibility of qualified and anonymous advice on herpes infections in Sweden, a telephone counselling service was initiated in November 1994. The nucleus of the service is an answering machine that works around the clock. A caller can choose one of 3 different messages dealing with labial or genital herpes infection or herpes zoster--each message is approximately 3 min long. Those wanting written information can register and have material sent to them. For 2 h daily, 4 days a week, calls pass directly to the staff of the sexually transmitted diseases clinic of the University Hospital in Uppsala, Sweden--the caller pays only a single telephone unit charge. The personal calls deal with all aspects of herpes infections. During the first 3 months of the counselling service more than 4,500 calls were received.

Epstein-Barr virus (EBV) is present, as both latent and replicating virus, in most healthy individuals, and disturbance of the normal host-virus balance may cause a variety of diseases. A number of diagnostic tools can he used, depending upon the particular condition investigated, however, serology is the best method for diagnosis of primary EBV infections. In approximately 85% of cases of mononucleosis, the primary EBV infection can he diagnosed by an assay for heterophile antibodies. The presence of immunoglobulin G (IgG) and IgM to antigens from the replicative cycle of the virus, in combination with absence of antibodies to the EBV nuclear antigens (EBNA 1-6), is a diagnostic for a primary EBV infection. Serological tests for elevated IgA levels to various EBV antigens have been used to screen for EBV-associated nasopharyngeal carcinoma. In those with AIDS with EBV-associated lymphomas of the brain, EBV genomes can always be detected with polymerase chain reaction on cerebrospinal fluid. Epstein-Barr virus involvement in tumours, other than those of the brain and solid organs, can be verified by in situ demonstration of EBV-DNA or by immunocytochemical techniques for viral antigens.

Ceftazidime has reduced the mortality of severe disease by half, but melioidosis remains a difficult and expensive infection to treat. Empirical treatment of septicemia with aminoglycosides combined with penicillin, ampicillin, or second-generation cephalosporins is ineffective. The response to appropriate antibiotic treatment is slow, and most patients require a minimum of 2 weeks of high-dose parenteral treatment. Large abscesses should be drained if possible. Ceftazidime remains the drug of choice, but co-amoxyclav is an effective alternative (although treatment failure rates are slightly higher), and preliminary experience with imipenem is encouraging. The relapse rate following 8 weeks of treatment is approximately 28%, and this is reduced to 9% with 20 weeks of treatment. The relapse rate is determined by the extent of the infection and not the underlying predisposing condition. Resistance to all treatment antimicrobials has been documented, but this has not proved a major problem to date. Patients who survive the acute phase of melioidosis require life-long follow-up.

High rates of acinetobacter bacteremia were observed in a large teaching hospital in Hong Kong. A retrospective study of 94 acinetobacter bacteremic episodes in patients in 1993-94 revealed 70 episodes of significant bacteremia. 53% of the patients were over 60 years with a male to female ratio of 1.5:1. Cases were most rare during the fourth quarter. The intensive care unit was the commonest location of acquisition of bacteremia. Most infections were hospital acquired. Intravascular catheters, urinary catheters, antibiotic therapy and respiratory tract manipulations were common risk factors. Lower respiratory tract infections and catheter-related sepsis were predominant foci of bacteremia. One-third of the patients received appropriate antibiotics within 48 hours after bacteremia onset. Mortality attributable to acinetobacter infection was 27%. Prognosis of underlying diseases, location in intensive care unit, lower respiratory tract infection as foci of infection as well as diabetes mellitus were associated with mortality.

Endotoxic lipopolysaccharide (LPS) is a major constituent of the outer membrane of the Gram-negative microbe. Following its release from the bacterium, LPS serves as a potent proinflammatory stimulus by interacting with humoral and cellular mediator systems to stimulate production of an array of inflammatory molecules. Cell-wall active antibiotics are known to promote endotoxin release. To assess the contribution of antibiotic-induced endotoxin release in the pathogenesis of Gram-negative sepsis, we have developed several experimental models in which mice have been pretreated with various agents to make them sensitive to Gram-negative (E. coli, pseudomonas) infection and/or the lethal effects of endotoxin. For the former, both cyclophosphamide (which renders mice neutropenic) and the reversible hepatotoxin D-galactosamine (D-gal) have been used. D-gal also sensitized mice to the lethal effects of LPS. Infected mice treated with cell-wall active antibiotics are protected approximately five- to 10-fold (as assessed by increases in LD50) if they are sensitive to LPS lethality (D-gal treatment) but 500-fold if they are resistant to LPS lethality. Importantly, different antibiotics that have been documented to cause different amounts of endotoxin release in vitro also differ in their protective efficacy in vivo. Thus, imipenem, which causes relatively low endotoxin release, is significantly more protective (8-fold) than ceftazidime or meropenem (3-fold, P < 0.005) under conditions of equivalent MICs. Lethality data correlate well with circulating levels of interleukin-6 (Il-6) in vivo and with induction of Il-6 in ex vivo studies in which anticoagulated mouse blood is incubated with bacteria and antibiotics. Finally, antiendotoxin agents manifest additional levels of protection in vivo under conditions in which antibiotics alone are not protective. Collectively, these results strongly implicate antibiotic-induced endotoxin release as a significant contributing factor in experimental Gram-negative sepsis.

Several parameters of shingles' pain can be measured and each provides meaningful information. Generally, the more comprehensive the assessment the better, but there are significant difficulties in measuring the duration of post-herpetic neuralgia (PHN). Patients with herpes zoster usually feel pain as a continuum and, although acute pain and PHN have different qualities and pathophysiologies, we lack the sophistication to determine when PHN commences. Use of an arbitrarily defined starting point is meaningless for the patient and may introduce statistical bias (particularly if acute pain and PHN are divided by the point of rash healing). Thus, measurement of the pain as a continuum ('zoster-associated pain') is advocated. We also need to decide what degree of pain intensity is meaningful and whether complete cessation of pain or loss of pain (or only 'moderate/severe' pain) for a finite period is a better assessment. This approach to pain measurement was recently adopted in a meta-analysis of the placebo-controlled trials of oral aciclovir in herpes zoster. When 'time to complete cessation of all pain' was assessed, the hazard ratio was 2.13 in favour of aciclovir, with a 95% confidence interval (CI) of 1.42 to 3.19. For 'time to complete cessation of moderate/severe pain' the hazard ratio was 1.46 (95% CI; 1.11, 1.93); for 'time to first pain-free period' it was 1.31 (95% CI; 1.08, 1.60). These results indicate that aciclovir significantly speeds pain resolution in shingles.

Cytomegalovirus (CMV) infections are a major problem in transplant recipients, although recent advances in diagnosis, prevention and therapy have reduced the risk of CMV disease. To illustrate these advances, the risks of CMV disease and subsequent death were analyzed in 482 consecutive bone marrow transplant (BMT) patients transplanted between 1975 and 1994. No CMV-seronegative patient with seronegative donor marrow developed disease. Among the remaining 384 patients, the risk for CMV disease was reduced from 13.0% in patients transplanted between 1975 and 1985 to 2.2% in those transplanted between 1991 and 1994 (p = 0.06). The corresponding risks for death due to CMV disease were reduced from 13.0% to 0% (p = 0.002). Significant factors in multivariate analysis for the reduction of death from CMV disease were acute graft-versus-host disease and pre-emptive therapy based on rapid diagnosis with polymerase chain reaction. These data are discussed in relation to previously published results in BMT and solid organ transplant patients.

Malaria remains one of the major health problems in many tropical countries. Plasmodium falciparum is the most common malaria parasite in Africa, and it causes much more severe and progressive illness than any of the other types of malaria parasite. Children living in sub-Saharan Africa are bearing the major burden of the disease and the mortality. Whatever parameter is used to measure the mortality or the morbidity from malaria, the true problem is likely to be underestimated. The pattern of morbidity and mortality depends on the transmission intensity; the more intensity of malaria transmission is increased, the earlier and more confined the age range of symptomatic malaria. The asymptomatic carrier status is common, and 60-80% of the children in highly endemic areas have P. falciparum parasitaemia at any given time. Consequently a case definition based on the mere presence of parasites in the blood is non-informative in terms of measuring morbidity. Recognizing that there are no specific diagnostic clinical parameters for malaria, but that fever is very common, and that morbidity is to some extent dependent on the parasite density, we described using a logistic regression model the probability of being sick from malaria in relation to body temperature and parasite density. Acquired clinical and parasitological immunity develop progressively over several years after repeated exposure to infection. Protection is acquired first against death or severe clinical disease, then against milder clinical attacks, but protection against infection is never complete. Clinical and parasitological immunity develop concomitantly, as demonstrated by relating the parasite densities to measured body temperature. However, the ability to control the disease and parasite density develops earlier than the ability to prevent the parasite infection. The individual immune mechanisms that are responsible for the acquired immunity remain uncertain, but classical transfer experiments with polyvalent gamma globulin from immune donors to non-immune individuals showed that antibodies play an important role. Potential targets for malarial vaccines include antigens on the surface of the sporozoites and the merozoites. Several protein antigens from P. falciparum have been characterized at the molecular level, and most of the characterized antigens have the common characteristic that they are recognized by immune sera from individuals living in malaria endemic areas. Working on the approach that potentially useful targets for protective vaccine development can be identified by correlating the naturally acquired immune responses with defined P. falciparum antigens, we examined antigens from both the sporozoite stage (CS-protein) and the blood stages (Pf155/RESA, GLURP, and MSP1), as well as P. falciparum induced neoantigens on the red blood cell (band-3 neoantigens). The relationship between the immune response to these defined P. falciparum antigens and clinical and parasi

In many western countries, successful control of bacterial sexually transmitted diseases (STDs) has contrasted with an increase in the prevalence of viral STDs. The continued increase in clinical and subclinical genital herpes infections is of particular concern because of the implications for the risk of coincident spread of human immunodeficiency virus infection. Advances in knowledge of the epidemiology and natural history of genital herpes must be the basis of renewed educational efforts targeted at the general public, healthcare professionals, as well as infected persons. Diagnostic techniques, such as polymerase chain reaction and type-specific serology, now allow increased detection of subclinical infection. However, infected persons must be assured of access to effective antiviral treatment and comprehensive holistic management if the clinical and epidemiological benefits of detection are to outweigh the psychological and psychosocial disadvantages of being infected with a stigmatized condition. Vaccines could offer the best prospect for both primary prophylaxis and immunotherapy of genital herpes, and may have the greatest impact in limiting the spread of this infection. Recent progress has been made in the development of effective and safe vaccines, and their successful introduction should be a major priority over the next decade.