High rates of multiple antibiotic resistance in Streptococcus pneumoniae from healthy children living in isolated rural communities: association with cephalosporin use and intrafamilial transmission

OBJECTIVE

Streptococcus pneumoniae is one of the most clinically significant pathogens with emerging antibiotic resistance. We performed a surveillance study in isolated rural populations of healthy children to estimate the prevalence of pneumococcal resistance and to contrast factors that predict pneumococcal carriage with those that specifically predict resistant pneumococcal carriage.

METHODS

The study was conducted in 1998 in 2 rural communities in Utah. Families were recruited directly for participation through community canvassing. Surveillance nasopharyngeal cultures were obtained from children who were younger than 8 years. Antibiotic usage and information on other potential risk factors were obtained from questionnaires and local pharmacy records. Resistance was determined by testing isolates for susceptibility to penicillin, cefaclor, trimethoprim-sulfamethoxazole, erythromycin, ceftriaxone, and trovafloxacin. Selected resistant isolates were characterized further by serotyping, pulsed field gel electrophoresis, and Southern blot with DNA probes specific for the pneumococcal lytA gene and for antibiotic resistance genes.

RESULTS

In April 1998, surveillance nasopharyngeal cultures were obtained from 368 children aged </=8 years in community A and 369 children in community B. The number of antibiotic courses per child within 1 year before culture was higher in community B than A (mean: 2.2 vs 1.7). Conversely, oral cephalosporins were more frequently used in community A than B (community A: 22% received cephalosporins within 4 months; community B: 12%). Colonization with S pneumoniae was detected in 24% of children in community A and 14% in community B; 36% of isolates from community A and 28% of isolates from community B were resistant or intermediately susceptible to at least 1 antibiotic tested. Reduced susceptibility was most common to trimethoprim-sulfamethoxazole and cefaclor (28% and 26%, respectively). Pneumococcal carriage (susceptible or resistant) was independently associated with age <5 years (odds ratio [OR]: 2.2), child care exposure (OR: 2.4), presence of a sibling with a positive culture (OR: 3.3), and residence in community A (OR: 1.7). Among carriers, age <2 years (OR: 2.6), use of cephalosporins within the preceding 4 months (OR: 2.7), and having a sibling colonized with resistant S pneumoniae (OR: 5.5) were independent predictors of reduced susceptibility or resistance. Each pair of resistant isolates from siblings was indistinguishable by pulsed field gel electrophoresis and other molecular typing techniques. Several pneumococcal isolates from these isolated rural areas had the molecular characteristics of international clones of multiple-drug-resistant pneumococci that have been associated with worldwide spread.

CONCLUSIONS

Young age and intrafamilial transmission were important risk factors for carriage of both susceptible and resistant S pneumoniae. In contrast, previous cephalosporin use was linked specifically to resistant pneumococcal carriage, which suggests that modifications in antibiotic usage patterns may have salutary effects on antimicrobial resistance. These results extend previous observations in large cities regarding the penetration of multiple-drug-resistant clones of pneumococci into community populations.

Excessive antibiotic use for acute respiratory infections in the United States

Estimating the amount and cost of excess antibiotic use in ambulatory practice and identifying the conditions that account for most excess use are necessary to guide intervention and policy decisions. Data from the 1998 National Ambulatory Medical Care Survey, a sample survey of United States ambulatory physician practices, was used to estimate primary care office visits and antibiotic prescription rates for acute respiratory infections. Weight-averaged antibiotic costs were calculated with use of 1996 prescription marketing data and adjusted for inflation. In 1998, an estimated 76 million primary care office visits for acute respiratory infections resulted in 41 million antibiotic prescriptions. Antibiotic prescriptions in excess of the number expected to treat bacterial infections amounted to 55% (22.6 million) of all antibiotics prescribed for acute respiratory infections, at a cost of approximately $726 million. Upper respiratory tract infections (not otherwise specified), pharyngitis, and bronchitis were the conditions associated with the greatest amount of excess use. This study documents that the amount and cost of excessive antibiotic use for acute respiratory infections by primary care physicians are substantial and establishes potential target rates for antibiotic treatment of selected conditions.

Principles of appropriate antibiotic use for treatment of uncomplicated acute bronchitis: background

The following principles of appropriate antibiotic use for adults with acute bronchitis apply to immunocompetent adults without complicating comorbid conditions, such as chronic lung or heart disease.1.

The evaluation of adults with an acute cough illness or a presumptive diagnosis of uncomplicated acute bronchitis should focus on ruling out serious illness, particularly pneumonia. In healthy, nonelderly adults, pneumonia is uncommon in the absence of vital sign abnormalities or asymmetrical lung sounds, and chest radiography is usually not indicated. In patients with cough lasting 3 weeks or longer, chest radiography may be warranted in the absence of other known causes.

2.

Routine antibiotic treatment of uncomplicated acute bronchitis is not recommended, regardless of duration of cough. If pertussis infection is suspected (an unusual circumstance), a diagnostic test should be performed and antimicrobial therapy initiated.

3.

Patient satisfaction with care for acute bronchitis depends most on physician–patient communication rather than on antibiotic treatment.

[Gonzales R, Bartlett JG, Besser RE, Cooper RJ, Hickner JM, Hoffman JR, Sande MA. Principles of appropriate antibiotic use for treatment of uncomplicated acute bronchitis: background. Ann Emerg Med. June 2001;37:720-727.]

Principles of appropriate antibiotic use for treatment of nonspecific upper respiratory tract infections in adults: background

The following principles of appropriate antibiotic use for adults with nonspecific upper respiratory tract infections apply to immunocompetent adults without complicating comorbid conditions, such as chronic lung or heart disease. 1. The diagnosis of nonspecific upper respiratory tract infection or acute rhinopharyngitis should be used to denote an acute infection that is typically viral in origin and in which sinus, pharyngeal, and lower airway symptoms, although frequently present, are not prominent. 2. Antibiotic treatment of adults with nonspecific upper respiratory tract infection does not enhance illness resolution and is not recommended. Studies specifically testing the impact of antibiotic treatment on complications of nonspecific upper respiratory tract infections have not been performed in adults. Life-threatening complications of upper respiratory tract infection are rare. 3. Purulent secretions from the nares or throat (commonly observed in patients with uncomplicated upper respiratory tract infection) predict neither bacterial infection nor benefit from antibiotic treatment.

Principles of appropriate antibiotic use for acute pharyngitis in adults: background

The following principles of appropriate antibiotic use for adults with acute pharyngitis apply to immunocompetent adults without complicated comorbid conditions, such as chronic lung or heart disease, and history of rheumatic fever. They do not apply during known outbreaks of group A streptococcus. 1. Group A beta-hemolytic streptococcus (GABHS) is the causal agent in approximately 10% of adult cases of pharyngitis. The large majority of adults with acute pharyngitis have a self-limited illness, for which supportive care only is needed. 2. Antibiotic treatment of adult pharyngitis benefits only those patients with GABHS infection. All patients with pharyngitis should be offered appropriate doses of analgesics and antipyretics, as well as other supportive care. 3. Limit antibiotic prescriptions to patients who are most likely to have GABHS infection. Clinically screen all adult patients with pharyngitis for the presence of the four Centor criteria: history of fever, tonsillar exudates, no cough, and tender anterior cervical lymphadenopathy (lymphadenitis). Do not test or treat patients with none or only one of these criteria, since these patients are unlikely to have GABHS infection. For patients with two or more criteria the following strategies are appropriate: (a) Test patients with two, three, or four criteria by using a rapid antigen test, and limit antibiotic therapy to patients with positive test results; (b) test patients with two or three criteria by using a rapid antigen test, and limit antibiotic therapy to patients with positive test results or patients with four criteria; or (c) do not use any diagnostic tests, and limit antibiotic therapy to patients with three or four criteria. 4. Throat cultures are not recommended for the routine primary evaluation of adults with pharyngitis or for confirmation of negative results on rapid antigen tests when the test sensitivity exceeds 80%. Throat cultures may be indicated as part of investigations of outbreaks of GABHS disease, for monitoring the development and spread of antibiotic resistance, or when such pathogens as gonococcus are being considered. 5. The preferred antibiotic for treatment of acute GABHS pharyngitis is penicillin, or erythromycin in a penicillin-allergic patient.

Principles of appropriate antibiotic use for treatment of acute respiratory tract infections in adults: background, specific aims, and methods

The need to decrease excess antibiotic use in ambulatory practice has been fueled by the epidemic increase in antibiotic-resistant Streptococcus pneumoniae. The majority of antibiotics prescribed to adults in ambulatory practice in the United States are for acute sinusitis, acute pharyngitis, acute bronchitis, and nonspecific upper respiratory tract infections (including the common cold). For each of these conditions--especially colds, nonspecific upper respiratory tract infections, and acute bronchitis (for which routine antibiotic treatment is not recommended)--a large proportion of the antibiotics prescribed are unlikely to provide clinical benefit to patients. Because decreasing community use of antibiotics is an important strategy for combating the increase in community-acquired antibiotic-resistant infections, the Centers for Disease Control and Prevention convened a panel of physicians representing the disciplines of internal medicine, family medicine, emergency medicine, and infectious diseases to develop a series of "Principles of Appropriate Antibiotic Use for Treatment of Acute Respiratory Tract Infections in Adults." These principles provide evidence-based recommendations for evaluation and treatment of adults with acute respiratory illnesses.This paper describes the background and specific aims of and methods used to develop these principles. The goal of the principles is to provide clinicians with practical strategies for limiting antibiotic use to the patients who are most likely to benefit from it. These principles should be used in conjunction with effective patient educational campaigns and enhancements to the health care delivery system that facilitate nonantibiotic treatment of the conditions in question.

Principles of appropriate antibiotic use for acute rhinosinusitis in adults: background

The following principles of appropriate antibiotic use for adults with acute rhinosinusitis apply to the diagnosis and treatment of acute maxillary and ethmoid rhinosinusitis in adults who are not immunocompromised. Most cases of acute rhinosinusitis diagnosed in ambulatory care are caused by uncomplicated viral upper respiratory tract infections. Bacterial and viral rhinosinusitis are difficult to differentiate on clinical grounds. The clinical diagnosis of acute bacterial rhinosinusitis should be reserved for patients with rhinosinusitis symptoms lasting 7 days or more who have maxillary pain or tenderness in the face or teeth (especially when unilateral) and purulent nasal secretions. Patients with rhinosinusitis symptoms that last less than 7 days are unlikely to have bacterial infection, although rarely some patients with acute bacterial rhinosinusitis present with dramatic symptoms of severe unilateral maxillary pain, swelling, and fever. Sinus radiography is not recommended for diagnosis in routine cases. Acute rhinosinusitis resolves without antibiotic treatment in most cases. Symptomatic treatment and reassurance is the preferred initial management strategy for patients with mild symptoms. Antibiotic therapy should be reserved for patients with moderately severe symptoms who meet the criteria for the clinical diagnosis of acute bacterial rhinosinusitis and for those with severe rhinosinusitis symptoms-especially those with unilateral facial pain-regardless of duration of illness. For initial treatment, the most narrow-spectrum agent active against the likely pathogens, Streptococcus pneumoniae and Haemophilus influenzae, should be used.

Principles of appropriate antibiotic use for treatment of uncomplicated acute bronchitis: background

The following principles of appropriate antibiotic use for adults with acute bronchitis apply to immunocompetent adults without complicating comorbid conditions, such as chronic lung or heart disease. The evaluation of adults with an acute cough illness or a presumptive diagnosis of uncomplicated acute bronchitis should focus on ruling out serious illness, particularly pneumonia. In healthy, nonelderly adults, pneumonia is uncommon in the absence of vital sign abnormalities or asymmetrical lung sounds, and chest radiography is usually not indicated. In patients with cough lasting 3 weeks or longer, chest radiography may be warranted in the absence of other known causes. Routine antibiotic treatment of uncomplicated acute bronchitis is not recommended, regardless of duration of cough. If pertussis infection is suspected (an unusual circumstance), a diagnostic test should be performed and antimicrobial therapy initiated. Patient satisfaction with care for acute bronchitis depends most on physician--patient communication rather than on antibiotic treatment.

Principles of appropriate antibiotic use for acute pharyngitis in adults: background

The following principles of appropriate antibiotic use for adults with acute pharyngitis apply to immunocompetent adults without complicated comorbid conditions, such as chronic lung or heart disease, and history of rheumatic fever. They do not apply during known outbreaks of group A streptococcus.1. Group A beta-hemolytic streptococcus (GABHS) is the causal agent in approximately 10% of adult cases of pharyngitis. The large majority of adults with acute pharyngitis have a self-limited illness, for which supportive care only is needed.2. Antibiotic treatment of adult pharyngitis benefits only those patients with GABHS infection. All patients with pharyngitis should be offered appropriate doses of analgesics and antipyretics, as well as other supportive care.3. Limit antibiotic prescriptions to patients who are most likely to have GABHS infection. Clinically screen all adult patients with pharyngitis for the presence of the four Centor criteria: history of fever, tonsillar exudates, no cough, and tender anterior cervical lymphadenopathy (lymphadenitis). Do not test or treat patients with none or only one of these criteria, since these patients are unlikely to have GABHS infection. For patients with two or more criteria the following strategies are appropriate: a) Test patients with two, three, or four criteria by using a rapid antigen test, and limit antibiotic therapy to patients with positive test results; b) test patients with two or three criteria by using a rapid antigen test, and limit antibiotic therapy to patients with positive test results or patients with four criteria; or c) do not use any diagnostic tests, and limit antibiotic therapy to patients with three or four criteria. 4. Throat cultures are not recommended for the routine primary evaluation of adults with pharyngitis or for confirmation of negative results on rapid antigen tests when the test sensitivity exceeds 80%. Throat cultures may be indicated as part of investigations of outbreaks of GABHS disease, for monitoring the development and spread of antibiotic resistance, or when such pathogens as gonococcus are being considered.5. The preferred antibiotic for treatment of acute GABHS pharyngitis is penicillin, or erythromycin in a penicillin-allergic patient.

Principles of appropriate antibiotic use for treatment of nonspecific upper respiratory tract infections in adults: background

The following principles of appropriate antibiotic use for adults with nonspecific upper respiratory tract infections apply to immunocompetent adults without complicating comorbid conditions, such as chronic lung or heart disease.1. The diagnosis of nonspecific upper respiratory tract infection or acute rhinopharyngitis should be used to denote an acute infection that is typically viral in origin and in which sinus, pharyngeal, and lower airway symptoms, although frequently present, are not prominent. 2. Antibiotic treatment of adults with nonspecific upper respiratory tract infection does not enhance illness resolution and is not recommended. Studies specifically testing the impact of antibiotic treatment on complications of nonspecific upper respiratory tract infections have not been performed in adults. Life-threatening complications of upper respiratory tract infection are rare.3. Purulent secretions from the nares or throat (commonly observed in patients with uncomplicated upper respiratory tract infection) predict neither bacterial infection nor benefit from antibiotic treatment.

Principles of appropriate antibiotic use for treatment of acute respiratory tract infections in adults: background, specific aims, and methods

The need to decrease excess antibiotic use in ambulatory practice has been fueled by the epidemic increase in antibiotic-resistant Streptococcus pneumoniae. The majority of antibiotics prescribed to adults in ambulatory practice in the United States are for acute sinusitis, acute pharyngitis, acute bronchitis, and nonspecific upper respiratory tract infections (including the common cold). For each of these conditions-especially colds, nonspecific upper respiratory tract infections, and acute bronchitis (for which routine antibiotic treatment is not recommended)-a large proportion of the antibiotics prescribed are unlikely to provide clinical benefit to patients. Because decreasing community use of antibiotics is an important strategy for combating the increase in community-acquired antibiotic-resistant infections, the Centers for Disease Control and Prevention convened a panel of physicians representing the disciplines of internal medicine, family medicine, emergency medicine, and infectious diseases to develop a series of "Principles of Appropriate Antibiotic Use for Treatment of Acute Respiratory Tract Infections in Adults." These principles provide evidence-based recommendations for evaluation and treatment of adults with acute respiratory illnesses.This paper describes the background and specific aims of and methods used to develop these principles. The goal of the principles is to provide clinicians with practical strategies for limiting antibiotic use to the patients who are most likely to benefit from it. These principles should be used in conjunction with effective patient educational campaigns and enhancements to the health care delivery system that facilitate nonantibiotic treatment of the conditions in question.

Principles of appropriate antibiotic use for acute rhinosinusitis in adults: background

The following principles of appropriate antibiotic use for adults with acute rhinosinusitis apply to the diagnosis and treatment of acute maxillary and ethmoid rhinosinusitis in adults who are not immunocompromised.1. Most cases of acute rhinosinusitis diagnosed in ambulatory care are caused by uncomplicated viral upper respiratory tract infections. 2. Bacterial and viral rhinosinusitis are difficult to differentiate on clinical grounds. The clinical diagnosis of acute bacterial rhinosinusitis should be reserved for patients with rhinosinusitis symptoms lasting 7 days or more who have maxillary pain or tenderness in the face or teeth (especially when unilateral) and purulent nasal secretions. Patients with rhinosinusitis symptoms that last less than 7 days are unlikely to have bacterial infection, although rarely some patients with acute bacterial rhinosinusitis present with dramatic symptoms of severe unilateral maxillary pain, swelling, and fever.3. Sinus radiography is not recommended for diagnosis in routine cases. 4. Acute rhinosinusitis resolves without antibiotic treatment in most cases. Symptomatic treatment and reassurance is the preferred initial management strategy for patients with mild symptoms. Antibiotic therapy should be reserved for patients with moderately severe symptoms who meet the criteria for the clinical diagnosis of acute bacterial rhinosinusitis and for those with severe rhinosinusitis symptoms-especially those with unilateral facial pain-regardless of duration of illness. For initial treatment, the most narrow-spectrum agent active against the likely pathogens, Streptococcus pneumoniae and Haemophilus influenzae, should be used.

Principles of appropriate antibiotic use for treatment of uncomplicated acute bronchitis: background

The following principles of appropriate antibiotic use for adults with acute bronchitis apply to immunocompetent adults without complicating comorbid conditions, such as chronic lung or heart disease.1. The evaluation of adults with an acute cough illness or a presumptive diagnosis of uncomplicated acute bronchitis should focus on ruling out serious illness, particularly pneumonia. In healthy, nonelderly adults, pneumonia is uncommon in the absence of vital sign abnormalities or asymmetrical lung sounds, and chest radiography is usually not indicated. In patients with cough lasting 3 weeks or longer, chest radiography may be warranted in the absence of other known causes.2. Routine antibiotic treatment of uncomplicated acute bronchitis is not recommended, regardless of duration of cough. If pertussis infection is suspected (an unusual circumstance), a diagnostic test should be performed and antimicrobial therapy initiated.3. Patient satisfaction with care for acute bronchitis depends most on physician-patient communication rather than on antibiotic treatment.

Uncomplicated acute bronchitis

Acute bronchitis is an acute cough illness in otherwise healthy adults that usually lasts 1 to 3 weeks. This review describes the pathophysiology of the condition and provides a practical approach to the evaluation and treatment of adults with uncomplicated acute bronchitis. Practical points to be made are:1. Respiratory viruses appear to cause the large majority of cases of uncomplicated acute bronchitis.2. Pertussis infection is present in up to 10% to 20% of adults with cough illness of more than 2 to 3 weeks' duration. No clinical features distinguish pertussis from nonpertussis infection in adults who were immunized against pertussis as children.3. Transient bronchial hyperresponsiveness appears to be the predominant mechanism of the bothersome cough of acute bronchitis.4. Ruling out pneumonia is the primary objective in evaluating adults with acute cough illness in whom comorbid conditions and occult asthma are absent or unlikely. In the absence of abnormalities in vital signs (heart rate > 100 beats/min, respiratory rate > 24 breaths/min, and oral body temperature > 38 degrees C), the likelihood of pneumonia is very low.5. Randomized, placebo-controlled trials do not support routine antibiotic treatment of uncomplicated acute bronchitis.6. Randomized, placebo-controlled trials have shown that inhaled albuterol decreases the duration of cough in adults with uncomplicated acute bronchitis.7. Intervention studies suggest that antibiotic treatment of acute bronchitis can be reduced by using a combination of patient and physician education. Decreased rates of antibiotic treatment are not associated with increased utilization, return visits, or dissatisfaction with care.

Routine use of anaerobic blood cultures: are they still indicated?

PURPOSE

To determine the number of patients with bacteremia and fungemia and to evaluate the utility of routine anaerobic blood cultures as part of the work-up for suspected bacteremia.

SUBJECTS AND METHODS

Retrospective review of microbiology data followed by selective chart review at a university-affiliated Veterans Affairs Medical Center. We determined the number of bacterial blood cultures drawn from January 1, 1994, to December 31, 1996, and the number of anaerobic, aerobic, and fungal isolates. Chart reviews were then performed on all patients with a positive anaerobic result.

RESULTS

There were 6,891 sets of blood cultures processed through the laboratory, yielding 1,626 patients with positive results. Anaerobic isolates were recovered from 36 patients (2.2%) in 48 bottles. Aerobic isolates were recovered from 1550 patients (95.3%), and fungal isolates were recovered from 40 patients (2.5%). Seven patients (0.4%) had true anaerobic bacteremia. All seven patients had an obvious source of anaerobic infection that was known or suspected before the cultures were drawn. Antibiotic changes were made in four of these patients after the positive anaerobic results were known. Antibiotic changes led to clinical improvement in one patient.

CONCLUSIONS

Routine use of anaerobic blood cultures rarely results in clinically important diagnostic or therapeutic benefits, based on the low incidence of anaerobic bacteremia in patients who are not at increased risk. Anaerobic blood cultures should be selectively ordered in patients at risk for anaerobic infections.

AIDS and the elderly

Individuals 50 years of age or older continue to account for at least 10% of AIDS cases reported to the Centers for Disease Control and Prevention in recent years. Little research is devoted to addressing the specific issues affecting diagnosis, treatment, and prevention of AIDS in older Americans. Survival rates among elderly individuals infected with human immunodeficiency virus (HIV) are consistently decreased in comparison with those for younger patients. Elderly individuals also are less likely to use a condom during sexual intercourse or to participate in routine HIV testing. This article reviews the current literature concerning the changing epidemiology of AIDS among older Americans. The article also addresses AIDS-related morbidity and mortality, treatment issues, and HIV-prevention behaviors among the elderly. Enhanced clinician awareness of HIV in the elderly, along with further research concerning HIV treatment and prevention, is necessary to improve survival and outcome for those patients.

A randomized comparison of the safety and efficacy of once-daily gentamicin or thrice-daily gentamicin in combination with ticarcillin-clavulanate

PURPOSE

The primary purpose of the clinical trial was to assess the safety and efficacy of once-a-day compared with three-times-a-day gentamicin in patients with serious infections who had protocol-determined peak serum aminoglycoside concentrations.

PATIENTS AND METHODS

A total of 249 hospitalized patients with suspected or proven serious infections were randomized in a 2:2:1 ratio to gentamicin given three times a day with ticarcillin-clavulanate (TC), gentamicin once a day with TC, or ticarcillin-clavulanate (TC) alone. The gentamicin once-a-day dosage for patients with estimated creatinine clearance values of > or =80 mL/min was 5.1 mg/kg. With lower creatinine clearance estimates, the mg/kg dosage of gentamicin was decreased, and the dosage intervals (once daily or three times a day) were maintained. Evaluability required documentation of achievement of protocol-defined peak serum gentamicin levels.

RESULTS

Of the total 175 evaluable patients, there were no significant differences found between treatment regimens with respect to clinical or microbiologic efficacy. Bedside audiometry proved impractical due to the frequency of altered mental state in ill patients. Based on the traditional increase in serum creatinine values from baseline values, no differences in renal toxicity between the treatment groups was identified. When changes in renal function were reanalyzed based on maintaining, as opposed to worsening, of renal function, preservation of renal function was better in the gentamicin once-a-day patients as opposed to the gentamicin three-times-a-day patients, P <0.01.

CONCLUSIONS

Gentamicin once a day plus TC, gentamicin three times a day plus TC, and TC alone had similar effects in seriously ill hospitalized patients. The incidence of nephrotoxicity was similar in the three treatment groups. Using a nonvalidated post-hoc analysis, renal function was better preserved in gentamicin once-a-day + TC and TC-only patients as opposed to gentamicin three-times-a-day + TC.

The abilities of a Staphylococcus epidermidis wild-type strain and its slime-negative mutant to induce endocarditis in rabbits are comparable

The abilities of a parent and mutant pair of Staphylococcus epidermidis strains, the slime-producing parent RP62A and its slime-negative mutant, to establish endocarditis in a rabbit model of aortic valve endocarditis and to accumulate and adhere to surfaces in vitro were compared. Vegetation titer and infection rate depended on the presence or absence of a catheter (P = 0.020) and on inoculum size (P < 0.001) but not on the infecting strain. The ability of the parent strain vis-à-vis its mutant to accumulate in vitro on surfaces as demonstrated in a slime test did not correlate with any enhancement in the development of endocarditis in the rabbit model. In vitro initial adherence rates were identical. Both isolates accumulated to the same reduced extent in vitro in the presence of serum, albumin, or gelatin. Adhesion was equally promoted by addition of fibronectin. These data suggest that the in vitro phenomenon of accumulation described as slime production in the absence of serum may not be an important virulence determinant in vivo.

Antibiotic prescribing for children with colds, upper respiratory tract infections, and bronchitis

CONTEXT

The spread of antibiotic-resistant bacteria is associated with antibiotic use. Children receive a significant proportion of the antibiotics prescribed each year and represent an important target group for efforts aimed at reducing unnecessary antibiotic use.

OBJECTIVE

To evaluate antibiotic-prescribing practices for children younger than 18 years who had received a diagnosis of cold, upper respiratory tract infection (URI), or bronchitis in the United States.

DESIGN

Representative national survey of practicing physicians participating in the National Ambulatory Medical Care Survey conducted in 1992 with a response rate of 73%.

SETTING

Office-based physician practices.

PARTICIPANTS

Physicians completing patient record forms for patients younger than 18 years.

MAIN OUTCOME MEASURES

Principal diagnoses and antibiotic prescriptions.

RESULTS

A total of 531 pediatric office visits were recorded that included a principal diagnosis of cold, URI, or bronchitis. Antibiotics were prescribed to 44% of patients with common colds, 46% with URIs, and 75% with bronchitis. Extrapolating to the United States, 6.5 million prescriptions (12% of all prescriptions for children) were written for children diagnosed as having a URI or nasopharyngitis (common cold), and 4.7 million (9% of all prescriptions for children) were written for children diagnosed as having bronchitis. After controlling for confounding factors, antibiotics were prescribed more often for children aged 5 to 11 years than for younger children (odds ratio [OR], 1.94; 95% confidence interval [CI], 1.13-3.33) and rates were lower for pediatricians than for nonpediatricians (OR, 0.57; 95% CI, 0.35-0.92). Children aged 0 to 4 years received 53% of all antibiotic prescriptions, and otitis media was the most frequent diagnosis for which antibiotics were prescribed (30% of all prescriptions).

CONCLUSIONS

Antibiotic prescribing for children diagnosed as having colds, URIs, and bronchitis, conditions that typically do not benefit from antibiotics, represents a substantial proportion of total antibiotic prescriptions to children in the United States each year.

Perspectives on switching oral acyclovir from prescription to over-the-counter status: report of a consensus panel

The proposed switching of oral acyclovir from prescription to over-the-counter (OTC) status for the 5-day episodic treatment of genital herpes was considered by a consensus panel. It was concluded that self-diagnosis/misdiagnosis, misuse, and adverse drug effects were potential problems with the OTC use of acyclovir. While acyclovir reduces asymptomatic shedding of herpes simplex virus type 2, the reduction in transmission of virus potentially resulting from increased acyclovir use was felt to be of unknown extent but likely to be of benefit overall. The availability of acyclovir would likely be improved. There were differences in opinion as to whether widespread availability of acyclovir (prescription or OTC) may speed the development of viral resistance. However, all panel members felt that granting OTC status may set an undesirable precedent for the switch from prescription to OTC use of other systemically administered antiinfective agents. The effect of this precedent, in terms of accelerating development of multidrug-resistant bacteria, was a major concern of all panel members. The consensus was that the switch of acyclovir to OTC status could not be supported.

Antibiotic prescribing for adults with colds, upper respiratory tract infections, and bronchitis by ambulatory care physicians

CONTEXT

Antibiotic use is associated with increased rates of antibiotic-resistant organisms. A previous study has shown that colds, upper respiratory tract infections, and bronchitis account for nearly one third of all antibiotic prescribing by ambulatory care physicians. How frequently antibiotics are prescribed for these conditions and for and by whom is not known.

OBJECTIVES

To measure antibiotic prescription rates and to identify predictors of antibiotic use for adults diagnosed as having colds, upper respiratory tract infections, and bronchitis in the United States.

DESIGN

Sample survey of practicing physicians participating in the National Ambulatory Medical Care Survey, 1992.

SETTING

Office-based physician practices.

SUBJECTS

Physicians (n=1529) completing patient record forms for adult office visits (n=28787).

MAIN OUTCOME MEASURES

Antibiotic prescriptions for colds, upper respiratory tract infections, and bronchitis.

RESULTS

Office visits for colds, upper respiratory tract infections, and bronchitis resulted in approximately 12 million antibiotic prescriptions, accounting for 21% of all antibiotic prescriptions to adults in 1992. A total of 51 % of patients diagnosed as having colds, 52% of patients diagnosed as having upper respiratory tract infections, and 66% of patients diagnosed as having bronchitis were treated with antibiotics. Female sex (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.05-2.62) and rural practice location (OR, 2.25; 95% CI, 1.33-3.80) were associated with greater antibiotic prescription rates, whereas black race (OR, 0.44; 95% CI, 0.21-0.93) was associated with lower antibiotic prescription rates. Patient age, Hispanic ethnicity, geographic region, physician specialty, and payment sources were not associated with antibiotic prescription rates in the bivariate analysis. Multivariate logistic regression analysis identified only rural practice location (adjusted OR, 2.58; 95% CI, 1.39-4.76) to be independently associated with more frequent antibiotic prescriptions for colds, upper respiratory tract infections, and bronchitis.

CONCLUSION

Although antibiotics have little or no benefit for colds, upper respiratory tract infections, or bronchitis, these conditions account for a sizable proportion of total antibiotic prescriptions for adults by office-based physicians in the United States. Overuse of antibiotics is widespread across geographical areas, medical specialties, and payment sources. Therefore, effective strategies for changing prescribing behavior for these conditions will need to be broad based.

Treatment of experimental cryptococcal meningitis with fluconazole: impact of dose and addition of flucytosine on mycologic and pathophysiologic outcome

Fluconazole is effective in the therapy of cryptococcal meningitis in patients with AIDS. The optimal dosage of fluconazole and the impact of combination with flucytosine are not known. In this study, rabbits with experimental cryptococcal meningitis were given fluconazole at low, intermediate, or high dose or in combination with a low or intermediate dose of flucytosine. Serial cerebrospinal fluid (CSF) examinations showed that all three doses of fluconazole and low-dose fluconazole in combination with intermediate-dose flucytosine were effective in reducing CSF cryptococcal titer, lactate, white blood cell count, and cryptococcal antigen (CRAG) titers. The intermediate and high doses of fluconazole reduced CSF fungal (P < .05) and CRAG (P < .001) titers earlier than low-dose fluconazole alone or in combination with flucytosine. Only the highest dose of fluconazole reduced brain edema after 7 days. In this model of cryptococcal meningitis, there was evidence of a dose response with fluconazole but no in vivo synergism with flucytosine.

Single-dose ampicillin/sulbactam versus ceftriaxone as treatment for uncomplicated gonorrhoea in a Ugandan STD clinic population with a high prevalence of PPNG infection

During the period November 1989 to March 1991 a total of 330 patients (269 males and 61 females) with signs and symptoms of uncomplicated lower genital tract infections with Neisseria gonorrhoeae were treated at a sexually transmitted disease clinic in Kampala, Uganda. Patients were randomized for treatment with either intramuscular ampicillin/sulbactam (1 g ampicillin/0.5 g sulbactam), plus 1 g probenecid orally, or ceftriaxone (250 mg). In those cases where N. gonorrhoeae was isolated and the patients returned for a follow-up visit, 70/74 (95%) of the patients treated with ampicillin/sulbactam and 71/72 (99%) of those treated with ceftriaxone had favourable clinical outcomes. All 24 patients with penicillinase-producing N. gonorrhoeae (PPNG) treated with ampicillin/sulbactam had a favourable clinical outcome compared with 95% (20/21) of those with PPNG treated with ceftriaxone. The infecting pathogen was eradicated in 65/71 (92%) of the evaluable patients treated with ampicillin/sulbactam and in 60/63 (95%) of the ceftriaxone group. Both drug regimens were well tolerated and there were no reports of adverse drug effects. In summary, in a predominantly male group of clinic patients in Kampala, Uganda, ampicillin/sulbactam was as safe and effective as ceftriaxone in treating uncomplicated gonococcal infections of the lower genital tract caused by either PPNG or non-PPNG strains.

Outcome for hospitalized patients with fever and neutropenia who are infected with the human immunodeficiency virus

We conducted a retrospective cohort study to evaluate the occurrence of bacteremia and associated mortality among hospitalized patients who were seropositive for the human immunodeficiency virus (HIV) and who developed fever and neutropenia following antineoplastic chemotherapy or for other reasons. Review of medical records revealed 224 episodes in 142 patients. Of these episodes, 57% occurred following antineoplastic chemotherapy, and 43% occurred under other circumstances. Members of the chemotherapy group had significantly less-advanced HIV disease, a lower mean absolute-neutrophil-count nadir, and a shorter duration of hospitalization. There was no difference between the two groups in the frequency of bacteremia or mortality due to all causes when they were compared by multivariate analysis. Statistically significant univariate and multivariate predictors of bacteremia included sepsis syndrome and concurrent infection. Predictors of mortality included sepsis syndrome, concurrent infection, bacteremia, and antimicrobial therapy. This study suggests that the cause of neutropenia in HIV-seropositive patients is not a predictor of the outcome of fever and neutropenic episodes. Instead, clinical presentation and concomitant illnesses have a greater impact on outcome for a patient.

Adjunctive folinic acid with trimethoprim-sulfamethoxazole for Pneumocystis carinii pneumonia in AIDS patients is associated with an increased risk of therapeutic failure and death

Ninety-two AIDS patients with Pneumocystis carinii pneumonia (PCP) were randomized to receive folinic acid or matching placebo in conjunction with trimethoprim-sulfamethoxazole in a prospective, double-blind trial. Neither frequency of dose-limiting toxicity (26% vs. 37%; P = .4) nor time to occurrence (P = .7) was associated with folinic acid use. Although incidence of neutropenia was lower in patients receiving folinic acid (23% vs. 47%; P = .03), time to occurrence of neutropenia did not differ (P = .4). Seven (7.6%) of 92 patients with confirmed PCP met criteria for therapeutic failure, and 5 (6%) died during therapy. Surprisingly, folinic acid use was associated with a higher rate of both therapeutic failure (15% vs. 0; P = .01) and death (11% vs. 0; P = .06). Time to therapeutic failure was shorter and probability of death greater in patients receiving folinic acid (P = .005, P = .02, respectively), even when adjusted for baseline arterial oxygen pressure, serum lactate dehydrogenase, respiratory rate, CD4 cell count, and peak serum level of trimethoprim or sulfamethoxazole.

Antiretroviral therapy for adult HIV-infected patients. Recommendations from a state-of-the-art conference. National Institute of Allergy and Infectious Diseases State-of-the-Art Panel on Anti-Retroviral Therapy for Adult HIV-Infected Patients

This document summarizes recommendations from a state-of-the-art conference convened to evaluate the role of nucleoside analogue reverse transcriptase inhibitors in the treatment of human immunodeficiency virus (HIV) infection. Data from controlled clinical trials of zidovudine, didanosine, and zalcitabine were reviewed by an expert panel, which then formulated guidelines to assist clinicians and HIV-infected patients in the use of these agents. Recommendations were framed in the context of clinical scenarios for patients with asymptomatic HIV infection who have not had prior antiretroviral therapy; those with signs and symptoms of HIV-related disease who have not received prior therapy; clinically stable patients who are tolerating initial zidovudine therapy; patients experiencing clinical progression while on zidovudine therapy; and those who are intolerant of antiretroviral therapy. The panel concluded that physicians need to integrate up-to-date scientific knowledge with other relevant needs to improve the care of HIV-infected patients.

Fluid administration, brain edema, and cerebrospinal fluid lactate and glucose concentrations in experimental Escherichia coli meningitis

The effect of no fluids versus liberal fluid supplementation on brain edema and cerebrospinal fluid (CSF) lactate and glucose concentrations was compared in rabbits with experimental Escherichia coli meningitis. Fluid restriction for the duration of the experiment (19 h) led to a decrease in body weight by approximately 5%, while the high fluid regimen increased body weight by approximately 5%. Infected animals developed brain edema compared with controls, but the fluid regimen had no measurable effect on the degree of edema. In contrast, fluid-restricted animals had significantly higher CSF lactate and lower CSF glucose concentrations than fluid-supplemented animals (lactate, 13.5 +/- 3.5 vs. 10.1 +/- 3.3 mmol/L; glucose, 1.89 +/- 1.39 vs. 4.11 +/- 1.39 mmol/L). These results fail to support the hypothesis that administration of large amounts of fluid in this model of gram-negative bacterial meningitis aggravates brain edema.

Sexual harassment in medical training

BACKGROUND

Sexual harassment has become a national concern and one that is increasingly recognized in the field of medicine. Although there are reports of the sexual harassment of medical trainees, there is little information on the prevalence of this problem and whether it is adequately addressed by training institutions.

METHODS

Surveys with descriptions and examples of sexual harassment were mailed to 133 internal medicine residents in a university training program. The residents were asked to report anonymously whether they had encountered sexual harassment during medical school or residency, the frequency and type of harassment, its effect on them, whether they chose to report it to a person in authority, and the factors that influenced this decision.

RESULTS

Surveys were returned by 82 residents (response rate, 62 percent), 33 women and 49 men. Twenty-four women (73 percent) and 11 men (22 percent) reported that they had been sexually harassed at least once during their training. The women were more likely than the men to have been physically harassed, and the women's harassers were of higher professional status. Among those harassed, 19 of the women (79 percent) and 5 of the men (45 percent) thought that the experience created a hostile environment or interfered with their performance at work, but only 2 women and no men reported their experiences to an authority. The women cited a lack of confidence that they would be helped as the main reason for not reporting the experience, whereas men most commonly said that they had dealt with the problem without the need for outside assistance.

CONCLUSIONS

Many medical trainees encounter what they believe to be sexual harassment during medical school or residency, and this often creates a hostile learning and work environment. Training institutions need to address the adverse effects this may have on medical education and patient care.

Toxoplasmosis of the central nervous system in the acquired immunodeficiency syndrome

BACKGROUND AND METHODS

Toxoplasmosis is the most common opportunistic infection of the central nervous system in patients with the acquired immunodeficiency syndrome (AIDS). To investigate its clinical course, we reviewed the records of 115 patients with AIDS and central nervous system toxoplasmosis treated at San Francisco General Hospital between 1981 and 1990.

RESULTS

The most common presenting symptoms were headache (in 55 percent), confusion (52 percent), and fever (47 percent). Focal neurologic deficits were present in 79 patients (69 percent). The median CD4 cell count at presentation was 50 per cubic millimeter (50 x 10(6) per liter). Thirteen of 80 patients with clinical toxoplasmosis (16 percent) and 4 of 18 patients with pathologically proved disease (22 percent) had undetectable antitoxoplasma IgG antibodies by indirect immunofluorescence assay. Of 103 patients, 94 (91 percent) had enhancing lesions on CT. Single lesions were seen in 28 of 103 patients (27 percent) on CT, and such lesions were seen in 3 of 21 patients (14 percent) on magnetic resonance imaging. Over 90 percent of patients who eventually had clinical and radiographic improvement had evidence of improvement by day 14 of therapy. Adverse drug reactions occurred in 71 patients (62 percent) and led to a change in therapy in 50 patients (43 percent). Among the patients who survived a first episode of toxoplasmosis, the median survival was 265 days.

CONCLUSIONS

Toxoplasmosis occurs in advanced stages of human immunodeficiency virus infection, and the absence of antitoxoplasma antibodies on immunofluorescence assay does not exclude the diagnosis. The clinical and radiographic response to therapy is usually rapid, but treatment is frequently limited by adverse drug effects.

Relationship between antibiotic concentration in bone and efficacy of treatment of staphylococcal osteomyelitis in rats: azithromycin compared with clindamycin and rifampin

We examined the effect of azithromycin (CP-62,993), a new oral macrolide-like antibiotic, alone and in combination with rifampin, as treatment for experimental staphylococcal osteomyelitis. Clindamycin was used as a comparison drug. Rats (n = 10 to 15 per group) were infected by direct instillation of Staphylococcus aureus into the tibial medullary cavity. After 10 days, 21-day treatments with azithromycin (50 mg/kg of body weight, once daily, by the oral route), rifampin (20 mg/kg, once daily, subcutaneously), or clindamycin (90 mg/kg, three times daily, by the oral route) were started. The drugs were used singly or in combination (azithromycin plus rifampin or clindamycin plus rifampin). Peak azithromycin concentrations in bone were > 30 times higher than levels in serum, but the drug had little effect on final bacterial titers (5.13 +/- 0.46 log10 CFU/g of bone; for controls, 6.54 +/- 0.28 log10 CFU/g). Clindamycin was more active than azithromycin (3.26 +/- 2.14 log10 CFU/g of bone; 20% of sterilized bones), but rifampin was the most active single drug (1.5 +/- 1.92 log10 CFU/g; 53% of sterilized bones). Therapy with rifampin or clindamycin alone was associated with the emergence of resistance. Rifampin plus azithromycin (0.51 +/- 1.08 log10 CFU/g of bone; 80% of sterilized bones) and rifampin plus clindamycin (0.87 +/- 1.34 log10 CFU/g of bone; 66% of sterilized bones) were the most active regimens. Thus, azithromycin is ineffective as a single drug for the treatment of experimental staphylococcal osteomyelitis, despite high levels in bone that markedly exceeded the MIC, but it may be an attractive partner drug for rifampin.

Evaluation of new anti-infective drugs for the treatment of acute bacterial meningitis. Infectious Diseases Society of America and the Food and Drug Administration

Predisposing conditions for acute bacterial meningitis include prematurity, young age, management in an intensive care setting, low socioeconomic background, and crowded living conditions. Clinical findings vary with age and may be nonspecific (altered feeding behavior) or specific (Kernig and Brudzinski signs). Examination and culture of cerebrospinal fluid (CSF) are essential for diagnosis. Antigen identification in CSF, serum, or urine by latex agglutination or other techniques can be useful in the identification of the pathogen. Randomized, controlled studies with a single-, double-, or evaluator-blinded design are encouraged. Among neonates, infants, and children, CSF should be examined again 24-36 hours after initiation of therapy. Outcomes should be judged by both clinical and microbiological criteria. Assessment of microbiological outcome is paramount.

Evaluation of new anti-infective drugs for the treatment of viral encephalitis. Infectious Diseases Society of America and the Food and Drug Administration

Viral encephalitis may develop subsequent to viremia, via neuronal spread, or by arthropod vector. Diagnosis often requires invasive studies such as lumbar puncture and brain biopsy. This guideline addresses herpes simplex, rabies, and arbovirus infections of the central nervous system. Clinical trials should be designed according to the availability of approved therapeutic agents. Study designs with an active control (herpesvirus), a placebo control (arbovirus), or no control (rabies virus) are recommended. Outcome should be assessed 4-6 weeks, 4-6 months, and 11-13 months after the completion of therapy. For newborns with encephalitis, outcome should be assessed yearly through the age of 5 years. Assessment of clinical outcome is paramount.

Evaluation of new anti-infective drugs for the treatment of cryptococcal meningitis. Infectious Diseases Society of America and the Food and Drug Administration

Cryptococcus neoformans may infect persons with intact or compromised host defenses. Clinical manifestations generally correlate directly with the degree of immunosuppression. Treatment is prescribed on the basis of the severity of disease and the degree of immunosuppression. Cryptococcal meningitis is the most common clinical form of cryptococcal infection and the most amenable to study in clinical trials. The current standard of care for cryptococcal meningitis is therapy with amphotericin B. Despite clinical improvement and microbiological suppression of the organism at the completion of therapy, the microbiological outcome will be identified as presumptive persistence if treatment is continued. Patients should be observed for 1 year after completion of therapy before a final assessment is made.

Evaluation of new anti-infective drugs for the treatment of toxoplasma encephalitis. Infectious Diseases Society of America and the Food and Drug Administration

Toxoplasma gondii is a protozoan that exists in three forms, all of which are potentially infectious for humans. After acute infection, cysts persist in the central nervous system and extraneural tissue. Human hosts with compromised immunity, particularly those with the acquired immunodeficiency syndrome, are vulnerable to reactivation and dissemination. The most common clinical expression of toxoplasma infection is encephalitis. The diagnosis is established by clinical presentation, computed tomography and/or magnetic resonance imaging, and detection of antibodies to T. gondii in serum of patients positive for human immunodeficiency virus. Brain biopsy may be performed. Protocols may be developed for the evaluation of new regimens for the treatment of acute encephalitis, the suppression of disease after treatment, or the prevention of reactivation before the onset of clinical disease. Assessment of clinical outcome is paramount.

The microbial etiology and antimicrobial therapy of adults with acute community-acquired sinusitis: a fifteen-year experience at the University of Virginia and review of other selected studies

Pretreatment sinus puncture was performed on 339 patients with acute community-acquired sinusitis (ACAS) between 1975 and 1990. Bacterial species recovered in titers of greater than or equal to 10(4) colony-forming units per milliliter (CFU/ml) from 383 sinus aspirates included Streptococcus pneumoniae, 92 (41%); Haemophilus influenzae, 79 (35%); anaerobes, 17 (7%); streptococcal species, 16 (7%); Moraxella catarrhalis, 8 (4%); Staphylococcus aureus, 7 (33%); and other, 8 (4%). Viruses (rhinovirus, parainfluenza virus, and influenza virus) and fungi (Aspergillus, zygomycoses, Phaeohyphomycis, Pseudallescheria, and Hyalohyphomycis) have also been reported to cause ACAS. Posttreatment sinus puncture was performed on 220 of the 339 patients in six studies to evaluate efficacy of selected antimicrobial agents in producing bacteriologic cure. Ampicillin, 500 mg four times daily; amoxicillin, 500 mg three times daily; trimethoprim-sulfamethoxazole, twice a day; cefaclor, 500 mg four times daily; bacampicillin, 800 mg twice a day; cyclacillin, 500 mg three times a day; cefuroxime axetil, 250 mg twice daily; amoxicillin-clavulanate, 500/125 three times daily; and loracarbef 400 mg twice daily, given in 10-day courses, produced bacteriologic cure in more than 90% of patients. Early studies were done before beta-lactamase-producing strains of H. influenzae were a frequent cause of ACAS in Charlottesville. Management of therapeutic failures is a difficult problem for which diagnostic and therapeutic sinus puncture and lavage, prolonged antimicrobial therapy, steroid therapy, and evaluation of allergy, immunodeficiency, and surgically correctable lesions of the osteomeatal complex are recommended.