Screening for HIV Infection: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

Approximately 1.1 million persons in the United States are currently living with HIV, and more than 700 000 persons have died of AIDS since the first cases were reported in 1981. There were approximately 38 300 new diagnoses of HIV infection in 2017. The estimated prevalence of HIV infection among persons 13 years and older in the United States is 0.4%, and data from the Centers for Disease Control and Prevention show a significant increase in HIV diagnoses starting at age 15 years. An estimated 8700 women living with HIV give birth each year in the United States. HIV can be transmitted from mother to child during pregnancy, labor, delivery, and breastfeeding. The incidence of perinatal HIV infection in the United States peaked in 1992 and has declined significantly following the implementation of routine prenatal HIV screening and the use of effective therapies and precautions to prevent mother-to-child transmission.

OBJECTIVE

To update the 2013 US Preventive Services Task Force (USPSTF) recommendation on screening for HIV infection in adolescents, adults, and pregnant women.

EVIDENCE REVIEW

The USPSTF reviewed the evidence on the benefits and harms of screening for HIV infection in nonpregnant adolescents and adults, the yield of screening for HIV infection at different intervals, the effects of initiating antiretroviral therapy (ART) at a higher vs lower CD4 cell count, and the longer-term harms associated with currently recommended ART regimens. The USPSTF also reviewed the evidence on the benefits (specifically, reduced risk of mother-to-child transmission of HIV infection) and harms of screening for HIV infection in pregnant persons, the yield of repeat screening for HIV at different intervals during pregnancy, the effectiveness of currently recommended ART regimens for reducing mother-to-child transmission of HIV infection, and the harms of ART during pregnancy to the mother and infant.

FINDINGS

The USPSTF found convincing evidence that currently recommended HIV tests are highly accurate in diagnosing HIV infection. The USPSTF found convincing evidence that identification and early treatment of HIV infection is of substantial benefit in reducing the risk of AIDS-related events or death. The USPSTF found convincing evidence that the use of ART is of substantial benefit in decreasing the risk of HIV transmission to uninfected sex partners. The USPSTF also found convincing evidence that identification and treatment of pregnant women living with HIV infection is of substantial benefit in reducing the rate of mother-to-child transmission. The USPSTF found adequate evidence that ART is associated with some harms, including neuropsychiatric, renal, and hepatic harms, and an increased risk of preterm birth in pregnant women. The USPSTF concludes with high certainty that the net benefit of screening for HIV infection in adolescents, adults, and pregnant women is substantial.

CONCLUSIONS AND RECOMMENDATION

The USPSTF recommends screening for HIV infection in adolescents and adults aged 15 to 65 years. Younger adolescents and older adults who are at increased risk of infection should also be screened. (A recommendation) The USPSTF recommends screening for HIV infection in all pregnant persons, including those who present in labor or at delivery whose HIV status is unknown. (A recommendation).

Preexposure Prophylaxis for the Prevention of HIV Infection: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

An estimated 1.1 million individuals in the United States are currently living with HIV, and more than 700 000 persons have died of AIDS since the first cases were reported in 1981. In 2017, there were 38 281 new diagnoses of HIV infection reported in the United States; 81% of these new diagnoses were among males and 19% were among females. Although treatable, HIV infection has no cure and has significant health consequences.

OBJECTIVE

To issue a new US Preventive Services Task Force (USPSTF) recommendation on preexposure prophylaxis (PrEP) for the prevention of HIV infection.

EVIDENCE REVIEW

The USPSTF reviewed the evidence on the benefits of PrEP for the prevention of HIV infection with oral tenofovir disoproxil fumarate monotherapy or combined tenofovir disoproxil fumarate and emtricitabine and whether the benefits vary by risk group, population subgroup, or regimen or dosing strategy; the diagnostic accuracy of risk assessment tools to identify persons at high risk of HIV acquisition; the rates of adherence to PrEP in primary care settings; the association between adherence and effectiveness of PrEP; and the harms of PrEP when used for HIV prevention.

FINDINGS

The USPSTF found convincing evidence that PrEP is of substantial benefit in decreasing the risk of HIV infection in persons at high risk of HIV acquisition. The USPSTF also found convincing evidence that adherence to PrEP is highly associated with its efficacy in preventing the acquisition of HIV infection; thus, adherence to PrEP is central to realizing its benefit. The USPSTF found adequate evidence that PrEP is associated with small harms, including kidney and gastrointestinal adverse effects. The USPSTF concludes with high certainty that the magnitude of benefit of PrEP with oral tenofovir disoproxil fumarate-based therapy to reduce the risk of acquisition of HIV infection in persons at high risk is substantial.

CONCLUSIONS AND RECOMMENDATION

The USPSTF recommends offering PrEP with effective antiretroviral therapy to persons at high risk of HIV acquisition. (A recommendation).

Screening for Elevated Blood Lead Levels in Children and Pregnant Women: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

Elevated blood lead levels in children are associated with neurologic effects such as behavioral and learning problems, lower IQ, hyperactivity, hearing problems, and impaired growth. In pregnant women, lead exposure can impair organ systems such as the hematopoietic, hepatic, renal, and nervous systems, and increase the risk of preeclampsia and adverse perinatal outcomes. Many of the adverse health effects of lead exposure are irreversible.

OBJECTIVE

To update the 2006 US Preventive Services Task Force (USPSTF) recommendation on screening for elevated blood lead levels in children and pregnant women.

EVIDENCE REVIEW

The USPSTF reviewed the evidence on the benefits and harms of screening for and treatment of elevated blood lead levels. In this update, an elevated blood lead level was defined according to the Centers for Disease Control and Prevention reference level of 5 μg/dL.

FINDINGS

The USPSTF found adequate evidence that questionnaires and other clinical prediction tools to identify asymptomatic children with elevated blood lead levels are inaccurate. The USPSTF found adequate evidence that capillary blood testing accurately identifies children with elevated blood lead levels. The USPSTF found inadequate evidence on the effectiveness of treatment of elevated blood lead levels in asymptomatic children 5 years and younger and in pregnant women. The USPSTF found inadequate evidence regarding the accuracy of questionnaires and other clinical prediction tools to identify asymptomatic pregnant women with elevated blood lead levels. The USPSTF found inadequate evidence on the harms of screening for or treatment of elevated blood lead levels in asymptomatic children and pregnant women. The USPSTF concluded that the current evidence is insufficient, and that the balance of benefits and harms of screening for elevated blood lead levels in asymptomatic children 5 years and younger and in pregnant women cannot be determined.

CONCLUSIONS AND RECOMMENDATION

The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for elevated blood lead levels in asymptomatic children. (I statement) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for elevated blood lead levels in asymptomatic pregnant persons. (I statement).

Pediatric Gastroesophageal Reflux Clinical Practice Guidelines: Joint Recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition

This document serves as an update of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) 2009 clinical guidelines for the diagnosis and management of gastroesophageal reflux disease (GERD) in infants and children and is intended to be applied in daily practice and as a basis for clinical trials. Eight clinical questions addressing diagnostic, therapeutic and prognostic topics were formulated. A systematic literature search was performed from October 1, 2008 (if the question was addressed by 2009 guidelines) or from inception to June 1, 2015 using Embase, MEDLINE, the Cochrane Database of Systematic Reviews and the Cochrane Central Register of Controlled Clinical Trials. The approach of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) was applied to define and prioritize outcomes. For therapeutic questions, the quality of evidence was also assessed using GRADE. Grading the quality of evidence for other questions was performed according to the Quality Assessment of Studies of Diagnostic Accuracy (QUADAS) and Quality in Prognostic Studies (QUIPS) tools. During a 3-day consensus meeting, all recommendations were discussed and finalized. In cases where no randomized controlled trials (RCT; therapeutic questions) or diagnostic accuracy studies were available to support the recommendations, expert opinion was used. The group members voted on each recommendation, using the nominal voting technique. With this approach, recommendations regarding evaluation and management of infants and children with GERD to standardize and improve quality of care were formulated. Additionally, 2 algorithms were developed, 1 for infants <12 months of age and the other for older infants and children.

Randomized Controlled Trial of a Clinic-Based Intervention to Promote Healthy Beverage Consumption Among Latino Children

The objective of this study was to evaluate an educational module for Latino parents about the health effects of sweet beverages. Latino parents were randomized to receive the beverage module or a control module. Child beverage consumption was assessed at baseline, 2 weeks, 2 months, and 3 months via a beverage recall survey. At 2-week follow-up, children of intervention participants had a mean reduction in 7-day total sugar-sweetened beverage and 100% fruit juice consumption of 16 ounces while controls had a mean increase of 4 ounces ( P = .01). At 2-month and 3-month follow-up, there was a reduction in mean total sugar-sweetened beverage and 100% fruit juice consumption among both intervention and control children. An educational module on beverages for Latino parents reduced child consumption of sweet beverages at 2-week follow-up. However, study participation appears to have also reduced controls' beverage consumption suggesting that frequent intensive surveys of beverage intake may be an intervention unto itself.

Protection of chickens vaccinated with combinations of commercial live infectious bronchitis vaccines containing Massachusetts, Dutch and QX-like serotypes against challenge with virulent infectious bronchitis viruses 793B and IS/1494/06 Israel variant 2

Infectious bronchitis virus (IBV) is a coronavirus which affects chickens of all ages. IBV mainly causes respiratory disease but can also result in reduced weight gain, reduced egg production, increased frequency of abnormal eggs and increased rates of mortality. Vaccination is the most important way to control the disease. Nevertheless, novel strains of infectious bronchitis (IB) continue to emerge in the field. In order to respond promptly, combinations of existing IB vaccines are frequently tested to see whether they can provide cross-protection. The efficacy of a combination of vaccines based on Massachusetts, Dutch and QX-like IB strains against emerging IB Israel variant 2 and IB 793B strains was assessed by means of four challenge studies. At least 80% of the birds vaccinated with IB H120 (Mass type) combined with IB D274 (Dutch type) followed by a QX-like IB vaccine booster or vaccinated with a combination of IB H120, IB D274 and QX-like IB were protected against a challenge with IB 793B. In addition, IB 1263 (Mass type) boosted by QX-like IB showed an 85% protection following challenge with IB 793B. A combination of IB H120 and IB D274 boosted by QX-like IB vaccine conferred 70% protection whilst H120 and IB D274 combination on its own showed 61.1% protection against Israel variant 2 challenge. IB 1263 boosted by a QX-like IB vaccine showed 50% protection against IB Israel variant 2. Therefore, it can be concluded that a combination of the IB H120, IB D274 and QX-like IB confers broad protection against different non-related virulent IB strains.

Early Administration of Azithromycin and Prevention of Severe Lower Respiratory Tract Illnesses in Preschool Children With a History of Such Illnesses: A Randomized Clinical Trial

IMPORTANCE

Many preschool children develop recurrent, severe episodes of lower respiratory tract illness (LRTI). Although viral infections are often present, bacteria may also contribute to illness pathogenesis. Strategies that effectively attenuate such episodes are needed.

OBJECTIVE

To evaluate if early administration of azithromycin, started prior to the onset of severe LRTI symptoms, in preschool children with recurrent severe LRTIs can prevent the progression of these episodes.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blind, placebo-controlled, parallel-group trial conducted across 9 academic US medical centers in the National Heart, Lung, and Blood Institute's AsthmaNet network, with enrollment starting in April 2011 and follow-up complete by December 2014. Participants were 607 children aged 12 through 71 months with histories of recurrent, severe LRTIs and minimal day-to-day impairment.

INTERVENTION

Participants were randomly assigned to receive azithromycin (12 mg/kg/d for 5 days; n = 307) or matching placebo (n = 300), started early during each predefined RTI (child's signs or symptoms prior to development of LRTI), based on individualized action plans, over a 12- through 18-month period.

MAIN OUTCOMES AND MEASURES

The primary outcome measure was the number of RTIs not progressing to a severe LRTI, measured at the level of the RTI, that would in clinical practice trigger the prescription of oral corticosteroids. Presence of azithromycin-resistant organisms in oropharyngeal samples, along with adverse events, were among the secondary outcome measures.

RESULTS

A total of 937 treated RTIs (azithromycin group, 473; placebo group, 464) were experienced by 443 children (azithromycin group, 223; placebo group, 220), including 92 severe LRTIs (azithromycin group, 35; placebo group, 57). Azithromycin significantly reduced the risk of progressing to severe LRTI relative to placebo (hazard ratio, 0.64 [95% CI, 0.41-0.98], P = .04; absolute risk for first RTI: 0.05 for azithromycin, 0.08 for placebo; risk difference, 0.03 [95% CI, 0.00-0.06]). Induction of azithromycin-resistant organisms and adverse events were infrequently observed.

CONCLUSIONS AND RELEVANCE

Among young children with histories of recurrent severe LRTIs, the use of azithromycin early during an apparent RTI compared with placebo reduced the likelihood of severe LRTI. More information is needed on the development of antibiotic-resistant pathogens with this strategy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01272635.

The administration of probiotics and synbiotics in immune compromised adults: is it safe?

This study aimed to systematically evaluate safety of probiotics and synbiotics in immune compromised adults (≥18 years). Safety was analysed using the Common Terminology Clinical Adverse Events (CTCAE version 4.0) classification, thereby providing an update on previous reports using the most recent available clinical data (2008-2013). Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. Analysis of 57 clinical studies indicates that probiotic and/or synbiotic administration in immune compromised adults is safe with regard to the current evaluated probiotic strains, dosages and duration. Individuals were considered immune compromised if HIV-infected, critically ill, underwent surgery or had an organ- or an autoimmune disease. There were no major safety concerns in the study, as none of the serious adverse events (AE)s were related, or suspected to be related, to the probiotic or synbiotic product and the study products were well tolerated. Overall, AEs occurred less frequent in immune compromised subjects receiving probiotics and/or synbiotics compared to the control group. In addition, the results demonstrated a flaw in precise reporting and classification of AE in most studies. Furthermore, generalisability of conclusions are greatly limited by the inconsistent, imprecise and potentially incomplete reporting as well as the variation in probiotic strains, dosages, administration regimes, study populations and reported outcomes. We argue that standardised reporting on adverse events (CTCAE) in 'food' studies should be obligatory, thereby improving reliability of data and re-enforcing the safety profile of probiotics.

Safety of probiotics and synbiotics in children under 18 years of age

This study aimed to systematically evaluate safety of probiotics and synbiotics in children ageing 0-18 years. This study is the third and final part in a safety trilogy and an update is provided using the most recent available clinical data (2008-2013) by means of the Common Terminology Clinical Adverse Events (CTCAE version 4.0) classification. Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. Analysis of 74 clinical studies indicated that probiotic and/or synbiotic administration in children is safe with regard to the specific evaluated strains, dosages and duration. The population of children include healthy, immune compromised and obese subjects, as well as subjects with intestinal disorders, infections and inflammatory disorders. This study revealed no major safety concerns, as the adverse events (AEs) were unrelated, or not suspected to be related, to the probiotic or synbiotic product. In general the study products were well tolerated. Overall, AEs occurred more frequent in the control arm compared to children receiving probiotics and/or synbiotics. Furthermore, the results indicate inadequate reporting and classification of AEs in the majority of the studies. In addition, generalizability of conclusions are greatly limited by the inconsistent, imprecise and potentially incomplete reporting as well as the variation in probiotic strains, dosages, administration regimes, study populations and reported outcomes.

Vitamin D insufficiency and severe asthma exacerbations in Puerto Rican children

RATIONALE

Vitamin D insufficiency (a serum 25(OH)D <30 ng/ml) has been associated with severe asthma exacerbations, but this could be explained by underlying racial ancestry or disease severity. Little is known about vitamin D and asthma in Puerto Ricans.

OBJECTIVES

To examine whether vitamin D insufficiency is associated with severe asthma exacerbations in Puerto Rican children, independently of racial ancestry, atopy, and time outdoors.

METHODS

A cross-sectional study was conducted of 560 children ages 6-14 years with (n = 287) and without (n = 273) asthma in San Juan, Puerto Rico. We measured plasma vitamin D and estimated the percentage of African racial ancestry among participants using genome-wide genotypic data. We tested whether vitamin D insufficiency is associated with severe asthma exacerbations, lung function, or atopy (greater than or equal to one positive IgE to allergens) using logistic or linear regression. Multivariate models were adjusted for African ancestry, time outdoors, atopy, and other covariates.

MEASUREMENTS AND MAIN RESULTS

Vitamin D insufficiency was common in children with (44%) and without (47%) asthma. In multivariate analyses, vitamin D insufficiency was associated with higher odds of greater than or equal to one severe asthma exacerbation in the prior year (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.5-4.9; P = 0.001) and atopy, and a lower FEV(1)/FVC in cases. After stratification by atopy, the magnitude of the association between vitamin D insufficiency and severe exacerbations was greater in nonatopic (OR, 6.2; 95% CI, 2-21.6; P = 0.002) than in atopic (OR, 2; 95% CI, 1-4.1; P = 0.04) cases.

CONCLUSIONS

Vitamin D insufficiency is associated with severe asthma exacerbations in Puerto Rican children, independently of racial ancestry, atopy, or markers of disease severity or control.

Infection control knowledge, attitudes, and practices among cystic fibrosis patients and their families

BACKGROUND

In 2003, the Cystic Fibrosis (CF) Foundation in the United States published evidence-based infection control guidelines and distributed these to CF care centers. However, it is unclear how well the guidelines have been disseminated to patients and families, how well patients and families understand the principles of infection control, and what barriers they experience implementing the guidelines.

METHODS

We assessed infection control knowledge, attitudes, and practices among CF patients and their families at 17 randomly selected CF centers. Anonymous surveys were completed by CF patients (≥16 years old) or their family members (patients <16 years old). To adjust for similarities of patients within each center, generalized estimating equations regression was used.

RESULTS

From January 2007 to May 2009, 1,399 respondents completed surveys of whom 38% were patients and 62% were family members (overall mean age of patients = 14 years). Overall, 65% of respondents were aware of the CF infection control guidelines, but only 30% had discussed them more than once with their CF care team. More than one discussion was associated with increased knowledge of infection control, including routes of pathogen transmission; the importance of avoiding close contact with other CF patients; increased confidence in practicing infection control; and increased belief in the health benefits of infection control.

CONCLUSIONS

This study revealed that many CF patients and families are aware of the infection control guidelines, but that few had discussed them more than once with their CF teams. These findings underscore the importance of engaging patients and their families in regular discussions about infection control that address questions and concerns including the potential impact of infection control on health and well-being. Further strategies are needed to overcome barriers to implementing these guidelines.

Barriers to Prescribing Controller Anti Inflammatory Medication among Puerto Rican Asthmatic Children with Public Insurance: Results of National Survey of Pediatricians

BACKGROUND: There are substantial disparities in dispensing patterns of long term control medications for asthma among children in Puerto Rico with public insurance as compared to those with private insurance. Public health insurance policy in Puerto Rico includes the cost of medications in the capitation paid to the primary care physicians and clinics. METHODS: Survey questionnaires were mailed to all pediatricians enrolled in the Puerto Rico College of Physicians (n=798) in addition to some pediatricians not enrolled in the College (n=25) for a total of 823 pediatricians. Of these, 722 were eligible pediatricians with 458 responding to the survey for a response rate of 63.4%. RESULTS: Most of the respondents expressed being moderately to very familiar with the National Asthma Education and Prevention Program (NAEPP) guidelines (71.7%) and with the NAEPP recommendations for controller asthma medication use (73.5%). Inadequate capitation to cover asthma medication (86.2%) and lack of adequate health insurance coverage of the patient (83.2%) however, were the most frequent barriers reported by pediatricians for prescribing controller asthma medication to children with public health insurance. The most frequent strategies used to provide controller asthma medication to these children were prescription of oral medications (59.5%) and giving away samples (44.7%). CONCLUSIONS: Current public health insurance policy in Puerto Rico creates a disincentive to the appropriate prescription of long term control medication for children with asthma. To improve the quality of asthma care of children in Puerto Rico, revision of this public health insurance policy is necessary.

Potential roles and clinical utility of prebiotics in newborns, infants, and children: proceedings from a global prebiotic summit meeting, New York City, June 27-28, 2008

Initial bacterial colonization, including colonization with health-positive bacteria, such as bifidobacteria and lactobacilli, is necessary for the normal development of intestinal innate and adaptive immune defenses. The predominance of beneficial bacteria in the gut microflora of breast-fed infants is thought to be, at least in part, supported by the metabolism of the complex mixture of oligosaccharides present in human breast milk, and a more adult-type intestinal microbiota is found in formula-fed infants. Inadequate gut colonization, dysbiosis, may lead to an increased risk of infectious, allergic, and autoimmune disorders later in life. The addition of appropriate amounts of selected prebiotics to infant formulas can enhance the growth of bifidobacteria or lactobacilli in the colonic microbiota and, thereby, might produce beneficial effects. Among the substrates considered as prebiotics are the oligosaccharides inulin, fructo-oligosaccharides, galacto-oligosaccharides, and lactulose. There are some reports that such prebiotics have beneficial effects on various markers of health. For example, primary prevention trials in infants have provided promising data on prevention of infections and atopic dermatitis. Additional well-designed prospective clinical trials and mechanistic studies are needed to advance knowledge further in this promising field.

Long-term outcomes of physician peer teaching

Research conducted in 10 cities assessed long-term pediatric asthma outcomes from a peer teaching intervention for physicians to improve their asthma-related clinical and counseling skills. Hypotheses were better outcomes for patients, symptom reduction, less health care use, and enhanced view of the physician. Peers trained 53 intervention group pediatricians (seeing 418 patients); 48 pediatricians (seeing 452 patients) were controls. Patients provided baseline and 2-year follow-up data, collected by telephone interview and from medical records. Intent-to-treat analyses used Poisson regression and general estimation equations. Treatment physicians' patients gave them higher performance ratings ( P = .02). Patients had fewer sleep disruptions from asthma symptoms ( P = .03). Those with baseline health care use had fewer ED visits ( P = .005), hospitalizations (P = .03), and urgent office visits (P = .001), and they made fewer phone calls to the doctor's office (P = .02). Treatment physicians spent no more patient visit time than control physicians. Peer training increased patient's positive views of clinician's performance and reduced children's symptoms and health care use up to two years post program.

Barriers to adherence to cystic fibrosis infection control guidelines

BACKGROUND

In 2003, the American Cystic Fibrosis (CF) Foundation published revised, evidence-based guidelines for infection control. We sought to assess potential barriers to adherence to these guidelines experienced by health care professionals (HCPs) caring for CF patients.

METHODS

From April 2004 to December 2005, a knowledge, attitude, and practice survey was administered to HCPs at randomly selected CF centers in the United States to explore potential barriers to adherence to selected guidelines: (1) obtaining quarterly cultures from CF patients, (2) discouraging socialization among CF patients during hospitalization, (3) educating patients and families about hand hygiene, (4) educating patients and families to clean and disinfect home nebulizers, and (5) cleaning the clinic exam rooms between CF patients.

RESULTS

The survey was completed by 528 HCPs from 25 sites (5-50 respondents per site). Only 60% of respondents were aware of the guidelines, but despite awareness, 31-47% were unfamiliar with the specific guidelines. Self-reported adherence was low; only 23-63% of respondents reported practicing the selected guidelines >75% of the time/opportunities. Lack of self-efficacy, that is, confidence in adequately performing the guidelines, was commonly experienced by respondents. Access to a copy of the guidelines was associated with increased agreement with the recommendations and increased self-efficacy.

CONCLUSIONS

Strategies to reduce barriers to adherence to CF infection control guidelines are needed. Strategies could include quality improvement initiatives with enhanced education and skills workshops, sharing successful interventions among CF centers, and linking adherence to improved patient outcomes.

Microbial manipulation of immune function for asthma prevention: inferences from clinical trials

The "hygiene hypothesis" proposes that the increase in allergic diseases in developing countries reflects a decrease in infections during childhood. Cohort studies suggest, however, that the risks of asthma are increased in children who suffer severe illness from a viral respiratory infection in infancy. This apparent inconsistency can be reconciled through consideration of epidemiologic, clinical, and animal studies. The elements of this line of reasoning are that viral infections can predispose to organ-specific expression of allergic sensitization, and that the severity of illness is shaped by the maturity of immune function, which in turn is influenced by previous contact with bacteria and viruses, whether pathogenic or not. Clinical studies of children and interventional studies of animals indeed suggest that the exposure to microbes through the gastrointestinal tract powerfully shapes immune function. Intestinal microbiota differ in infants who later develop allergic diseases, and feeding Lactobacillus casei to infants at risk has been shown to reduce their rate of developing eczema. This has prompted studies of feeding probiotics as a primary prevention strategy for asthma. We propose that the efficacy of this approach depends on its success in inducing maturation of immune function important in defense against viral infection, rather than on its effectiveness in preventing allergic sensitization. It follows that the endpoints of studies of feeding probiotics to infants at risk for asthma should include not simply tests of responsiveness to allergens, but also assessment of intestinal flora, immune function, and the clinical response to respiratory viral infection.

Outcomes associated with spirometry for pediatric asthma in a managed care organization

BACKGROUND

The National Heart, Lung and Blood Institute asthma guidelines recommend that children with asthma receive spirometry testing "at least every 1 to 2 years to assess the maintenance of airway function."

OBJECTIVE

The purpose of this work was to describe: (1) how often children with asthma receive spirometry testing, (2) what factors are associated with receipt of spirometry testing, and (3) the impact of spirometry testing on subsequent emergency department visits for asthma.

METHODS

We analyzed all pediatric asthma claims data from a university-based managed care organization for a 3-year period (January 2001 to December 2003). We included all of the continuously enrolled patients with active asthma between 7 and 21 years of age. Our outcomes of interest were the presence of > or = 1 claim for spirometry testing (Common Procedural Terminology 94010-6, 94060, 94070, or 94150) and the time to emergency department visit. We used multivariate logistic regression to determine factors associated with receipt of spirometry and survival analyses techniques to assess the association between receipt of spirometry with the likelihood of an emergency department asthma visit in the next year, controlling for patient age, gender, severity of illness, and type of insurance.

RESULTS

There were 2688 eligible children of whom 1509 (56%) were male, 324 (12%) had Medicaid insurance, and 624 (24%) had persistent asthma in the initial year. Of the 2688 children, only 612 (23%) had > or = 1 claim for spirometry testing during the study period. In all of the multivariate logistic analysis models, increased severity of illness was consistently associated with increased likelihood of receiving spirometry testing. Compared with patients without Medicaid insurance, children with Medicaid insurance were consistently less likely to receive spirometry testing. After adjusting for age, gender, severity, and insurance type, receipt of spirometry did not affect the likelihood of future emergency department asthma use.

CONCLUSIONS

Children with Medicaid insurance are less likely to receive spirometry testing. Reasons may be because of access to care, inadequate provider referral for testing, or patient preferences. Objective lung function tests, such as spirometry, are a potentially important component of monitoring chronic disease status. However, it is not clear whether spirometry testing by itself, completed every 1 to 2 years, helps prevent the likelihood of emergency department asthma visits. Compared with guideline recommendations, spirometry is underused; however, additional work is needed to understand how to best integrate such testing to improve asthma outcomes.

Receipt of asthma subspecialty care by children in a managed care organization

BACKGROUND

Although proper outpatient asthma management sometimes requires care from subspecialists, there is little information on factors affecting receipt of subspecialty care in a managed care setting.

OBJECTIVE

To determine factors associated with receipt of subspecialty care for children with asthma in a managed care organization.

METHODS

We conducted an analysis of the claims from 3163 children with asthma enrolled in a university-based managed care organization from January 1998 to October 2000. We used logistic regression analysis to determine factors associated with an outpatient asthma visit with an allergist or pulmonologist.

RESULTS

Of the 3163 patients, 443 (14%) had at least 1 subspecialist visit for asthma; 354 (80%) were seen by an allergist, 63 (14%) were seen by a pulmonologist, and 26 (6%) were seen by both. In multivariate analysis, patients with more severe asthma (odds ratio [OR], 3.81; 95% confidence interval [CI], 2.99-4.86) and older patients (OR, 1.04; 95% CI, 1.02-1.07) were more likely to receive care from a subspecialist. Compared with Medicaid patients, both non-Medicaid patients with copayment (OR, 2.52; 95% CI, 1.85-4.43) and non-Medicaid patients without any copayment (OR, 3.40; 95% CI, 2.35-4.93) were more likely to receive care from an asthma subspecialist.

CONCLUSIONS

Children insured by Medicaid are less likely to receive care from subspecialists for asthma. Reasons may be due to health care system-related factors, such as accessibility of subspecialists, to physician referral decisions, and/or to patient factors, such as adherence to recommendations to see a subspecialist. Our findings suggest a need to further investigate health care system barriers, physician referral, and patient acceptance and completion of subspecialty referral.

The impact of practice guidelines in the management of Barrett esophagus: a national prospective cohort study of physicians

BACKGROUND

Surveillance of patients with Barrett esophagus (BE) is recommended to detect dysplasia and early cancer. In 1998, practice guidelines for the surveillance of patients with BE were developed under the auspices of the American College of Gastroenterology (ACG). Our objective is to assess physicians' awareness of agreement with and adherence to these guidelines.

METHODS

A national prospective cohort study of practicing gastroenterologists who completed a self-administered questionnaire containing case studies prior to the release of the guidelines and another survey 18 months later. Analysis of adherence to the guidelines was done using the McNemar chi(2) test.

RESULTS

Of the 154 gastroenterologists (66%) who responded to the follow-up survey, more than half (55%) were aware of the guidelines, and members of the ACG were more likely to know of their existence than nonmembers (61% vs 38%; P =.01). Overall, about 27% of physicians reported practicing in accordance with the guidelines at baseline; adherence increased modestly to 38% in the 18-month follow-up (P =.04) and was inversely related to fee-for-service reimbursement. Awareness was not associated with an increased likelihood of adherence, but agreement with the guidelines was strongly correlated with adherence (P<.001). The most frequent reasons for disagreement were concerns about liability, cancer risk, and inadequate evidence.

CONCLUSIONS

Awareness of the guidelines published by the ACG was low. Guideline awareness did not predict adherence. Improvement in guideline adherence will require steps beyond mere dissemination and promotion. Addressing disagreements about liability, disease risk, and scientific evidence as well as restructuring payment incentives may help achieve optimal practice.

A bacteriophage lambda-based genetic screen for characterization of the activity and phenotype of the human immunodeficiency virus type 1 protease

Human immunodeficiency virus type 1 (HIV-1) resistance to antiretroviral drugs is the main cause of patient treatment failure. Despite the problems associated with interpretation of HIV-1 resistance testing, resistance monitoring should help in the rational design of initial or rescue antiretroviral therapies. It has previously been shown that the activity of the HIV-1 protease can be monitored by using a bacteriophage lambda-based genetic assay. This genetic screening system is based on the bacteriophage lambda regulatory circuit in which the viral repressor cI is specifically cleaved to initiate the lysogenic to lytic switch. We have adapted this simple lambda-based genetic assay for the analysis of the activities and phenotypes of different HIV-1 proteases. Lambda phages that encode HIV-1 proteases either from laboratory strains (strain HXB2) or from clinical samples are inhibited in a dose-dependent manner by the HIV-1 protease inhibitors indinavir, ritonavir, saquinavir, and nelfinavir. Distinct susceptibilities to different drugs were also detected among phages that encode HIV-1 proteases carrying different resistance mutations, further demonstrating the specificity of this assay. Differences in proteolytic processing activity can also be directly monitored with this genetic screen system since two phage populations compete in culture with each other until one phage outgrows the other. In summary, we present here a simple, safe, and rapid genetic screening system that may be used to predict the activities and phenotypes of HIV-1 proteases in the course of viral infection and antiretroviral therapy. This assay responds appropriately to well-known HIV-1 protease inhibitors and can be used to search for new protease inhibitors.

Prevalence and route of transmission of infection with a novel DNA virus (TTV), hepatitis C virus, and hepatitis G virus in patients infected with HIV

OBJECTIVES

To evaluate the prevalence, route of transmission and clinical significance that current co-infection with TT virus (TTV), hepatitis C virus (HCV), and hepatitis G virus (HGV) have in HIV-1-infected patients.

DESIGN

Presence of TTV, HCV, and HGV was analyzed in plasma samples from 160 HIV-1-infected patients with parenteral (38 intravenous drug users [IVDUs] and 41 patients with hemophilia) or sexual (39 homosexuals and 42 heterosexuals) risk of exposure, and in 168 volunteer blood donors. Alanine aminotransferase (ALT) levels and CD4+ counts were also analyzed.

METHODS

HCV and HGV RNA were detected by specific reverse transcriptase (RT) nested polymerase chain reaction (PCR) and TTV DNA by specific heminested PCR.

RESULTS

TTV DNA was detected in 39% of the patients and in 14% of the volunteer blood donors. HCV and HGV infections were detected in 42% and in 14% of the patients, and in 0% and 3% of the blood donors, respectively. Prevalences of TTV and HCV infection were higher among patients with parenteral (62% and 68%) than in those with sexual (17% and 16%) risk of exposure. A higher prevalence of TTV infection (but not of HCV or HGV infection) was observed among patients with hemophilia (76%) than IVDUs (47%), and among homosexuals (26%) than among heterosexuals (10%). Abnormal ALT levels were related with the presence of HCV infection, independently of the detection of TTV DNA. TTV infection did not seem to alter the levels of CD4+ T cells.

CONCLUSIONS

Prevalence of current TTV infection is high among HIV-infected patients with parenteral risk of exposure, but TTV is also transmitted through sexual routes; detection of TTV does not seem to influence the clinical or immune status of HIV-infected patients.