Factors Related to Pertussis and Tetanus Vaccination Status Among Foreign-Born Adults Living in the United States.

Pertussis is a common vaccine-preventable disease (VPD) worldwide. Its reported incidence has increased steadily in the United States, where it is endemic. Tetanus is a rare but potentially fatal VPD. Foreign-born adults have lower tetanus-diphtheria-pertussis (Tdap) and tetanus-diphtheria (Td) vaccination coverage than do U.S.-born adults. We studied the association of migration-related, socio-demographic, and access-to-care factors with Tdap and Td vaccination among foreign-born adults living in the United States. The 2012 and 2013 National Health Interview Survey data for foreign-born respondents were analyzed. Multivariable logistic regression was conducted to calculate prevalence ratios and 95% confidence intervals, and to identify variables independently associated with Tdap and Td vaccination among foreign-born adults. Tdap and Td vaccination status was available for 9316 and 12,363 individuals, respectively. Overall vaccination coverage was 9.1% for Tdap and 49.8% for Td. Younger age, higher education, having private health insurance (vs. public insurance or uninsured), having visited a doctor in the previous year, and region of residence were independently associated with Tdap and Td vaccination. Among those reporting a doctor visit, two-thirds had not received Tdap. This study provides further evidence of the need to enhance access to health care and immunization services and reduce missed opportunities for Tdap and Td vaccination for foreign-born adults in the United States. These findings apply to all foreign-born, irrespective of their birthplace, citizenship, language and years of residence in the United States. Addressing vaccination disparities among the foreign-born will help achieve national vaccination goals and protect all communities in the United States.

Viral shedding and clinical illness in naturally acquired influenza virus infections.

BACKGROUND: Volunteer challenge studies have provided detailed data on viral shedding from the respiratory tract before and through the course of experimental influenza virus infection. There are no comparable quantitative data to our knowledge on naturally acquired infections. METHODS: In a community-based study in Hong Kong in 2008, we followed up initially healthy individuals to quantify trends in viral shedding on the basis of cultures and reverse-transcription polymerase chain reaction (RT-PCR) through the course of illness associated with seasonal influenza A and B virus infection. RESULTS: Trends in symptom scores more closely matched changes in molecular viral loads measured with RT-PCR for influenza A than for influenza B. For influenza A virus infections, the replicating viral loads determined with cultures decreased to undetectable levels earlier after illness onset than did molecular viral loads. Most viral shedding occurred during the first 2-3 days after illness onset, and we estimated that 1%-8% of infectiousness occurs prior to illness onset. Only 14% of infections with detectable shedding at RT-PCR were asymptomatic, and viral shedding was low in these cases. CONCLUSIONS: Our results suggest that "silent spreaders" (ie, individuals who are infectious while asymptomatic or presymptomatic) may be less important in the spread of influenza epidemics than previously thought.

Effects of oseltamivir treatment on duration of clinical illness and viral shedding and household transmission of influenza virus.

BACKGROUND: Large clinical trials have demonstrated the therapeutic efficacy of oseltamivir against influenza. We assessed the indirect effectiveness of oseltamivir in reducing secondary household transmission in an incident cohort of influenza index patients and their household members. METHODS: We recruited index outpatients whose rapid test results were positive for influenza from February through September 2007 and January through September 2008. Household contacts were followed up for 7-10 days during 3-4 home visits to monitor symptoms. Nose and throat swabs were collected and tested for influenza by reverse-transcription polymerase chain reaction or viral culture. RESULTS: We followed up 384 index patients and their household contacts. Index patients who took oseltamivir within 24 h of symptom onset halved the time to symptom alleviation (adjusted acceleration factor, 0.56; 95% confidence interval [CI], 0.42-0.76). Oseltamivir treatment was not associated with statistically significant reduction in the duration of viral shedding. Household contacts of index patients who had taken oseltamivir within 24 h of onset had a nonstatistically significant lower risk of developing laboratory-confirmed infection (adjusted odds ratio, 0.54; 95% CI, 0.11-2.57) and a marginally statistically significant lower risk of clinical illness (adjusted odds ratio, 0.52; 95% CI, 0.25-1.08) compared with contacts of index patients who did not take oseltamivir. CONCLUSIONS: Oseltamivir treatment is effective in reducing the duration of symptoms, but evidence of household reduction in transmission of influenza virus was inconclusive.

Facemasks and hand hygiene to prevent influenza transmission in households: a cluster randomized trial.

BACKGROUND: Few data are available about the effectiveness of nonpharmaceutical interventions for preventing influenza virus transmission. OBJECTIVE: To investigate whether hand hygiene and use of facemasks prevents household transmission of influenza. DESIGN: Cluster randomized, controlled trial. Randomization was computer generated; allocation was concealed from treating physicians and clinics and implemented by study nurses at the time of the initial household visit. Participants and personnel administering the interventions were not blinded to group assignment. (ClinicalTrials.gov registration number: NCT00425893) SETTING: Households in Hong Kong. PATIENTS: 407 people presenting to outpatient clinics with influenza-like illness who were positive for influenza A or B virus by rapid testing (index patients) and 794 household members (contacts) in 259 households. INTERVENTION: Lifestyle education (control) (134 households), hand hygiene (136 households), or surgical facemasks plus hand hygiene (137 households) for all household members. MEASUREMENTS: Influenza virus infection in contacts, as confirmed by reverse-transcription polymerase chain reaction (RT-PCR) or diagnosed clinically after 7 days. RESULTS: Sixty (8%) contacts in the 259 households had RT-PCR-confirmed influenza virus infection in the 7 days after intervention. Hand hygiene with or without facemasks seemed to reduce influenza transmission, but the differences compared with the control group were not significant. In 154 households in which interventions were implemented within 36 hours of symptom onset in the index patient, transmission of RT-PCR-confirmed infection seemed reduced, an effect attributable to fewer infections among participants using facemasks plus hand hygiene (adjusted odds ratio, 0.33 [95% CI, 0.13 to 0.87]). Adherence to interventions varied. LIMITATION: The delay from index patient symptom onset to intervention and variable adherence may have mitigated intervention effectiveness. CONCLUSION: Hand hygiene and facemasks seemed to prevent household transmission of influenza virus when implemented within 36 hours of index patient symptom onset. These findings suggest that nonpharmaceutical interventions are important for mitigation of pandemic and interpandemic influenza. PRIMARY FUNDING SOURCE: Centers for Disease Control and Prevention.

Antibiotics for bacteremic pneumonia: Improved outcomes with macrolides but not fluoroquinolones.

BACKGROUND: The questions of whether the use of antibiotics that are active against atypical organisms is beneficial in the treatment of community-acquired pneumonia and of the potential mechanisms of any beneficial effects remain unresolved. Proposed mechanisms include activity against atypical organisms vs the immunomodulatory effects of these antibiotics. The study of outcomes of a large cohort of patients with bacteremic pneumonia provides a unique opportunity to address these questions by excluding patients with primary atypical infection. METHODS: We reviewed data from the charts of 2,209 Medicare patients who were admitted to hospitals across the United States from either home or a nursing facility with bacteremic pneumonia between 1998 and 2001. Patients were stratified according to the type of antibiotic treatment. Multivariate modeling was performed to assess the relationship between the class of antibiotic used and several outcome variables. RESULTS: The initial use of any antibiotic active against atypical organisms was independently associated with a decreased risk of 30-day mortality (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.59 to 0.98; p = 0.03) and hospital admission within 30 days of discharge (OR, 0.67; 95% CI, 0.51 to 0.89; p = 0.02). Further analysis revealed that the benefits of atypical treatment were associated with the use of macrolides, but not the use of fluoroquinolones or tetracyclines, with macrolides conferring lower risks of in-hospital mortality (OR, 0.59; 95% CI, 0.40 to 0.88; p = 0.01), 30-day mortality (OR, 0.61; 95% CI, 0.43 to 0.87; p = 0.007), and hospital readmission within 30 days of discharge (OR, 0.59; 95% CI, 0.42 to 0.85; p = 0.004). CONCLUSIONS: Initial antibiotic treatment including a macrolide agent is associated with improved outcomes in Medicare patients hospitalized with bacteremic pneumonia. These results have implications regarding the mechanism by which the use of a macrolide for treatment of pneumonia is associated with improved outcomes.

Volume, quality of care, and outcome in pneumonia.

BACKGROUND: The establishment of minimum volume thresholds has been proposed as a means of improving outcomes for patients with various medical and surgical conditions. OBJECTIVE: To determine whether volume is associated with either quality of care or outcome in the treatment of pneumonia. DESIGN: Retrospective cohort study. SETTING: 3243 hospitals participating in the National Pneumonia Quality Improvement Project in 1998 and 1999. PATIENTS: 13,480 patients with pneumonia cared for by 9741 physicians. MEASUREMENTS: The association between the annual pneumonia caseload of physicians and hospitals and adherence to quality-of-care measures and severity-adjusted in-hospital and 30-day mortality rates. RESULTS: Physician volume was unrelated to the timeliness of administration of antibiotics and the obtainment of blood cultures; however, physicians in the highest-volume quartile had lower rates of screening for and administration of influenza (21%, 19%, 20%, and 12% for quartiles 1 through 4, respectively; P < 0.01) and pneumococcal (16%, 13%, 13%, and 9% for quartiles 1 through 4, respectively; P < 0.01) vaccines. Among hospitals, the percentage of patients who received antibiotics within 4 hours of hospital arrival was inversely related to pneumonia volume (72%, 64%, 60%, and 56% for quartiles 1 through 4, respectively; P < 0.01), while selection of antibiotic, obtainment of blood cultures, and rates of immunization were similar. Physician volume was not associated with in-hospital or 30-day mortality rates. Odds ratios for in-hospital mortality rates rose with increasing hospital volume (1.14 [95% CI, 0.87 to 1.49], 1.34 [CI, 1.03 to 1.75], and 1.32 [CI, 0.97 to 1.80] for quartiles 2 to 4, respectively); however, odds ratios for 30-day mortality rates were similar. LIMITATIONS: This study was limited to Medicare beneficiaries 65 years of age and older. Ascertainment of some measures of the quality of care and severity of illness depended on the documentation practices of the physician. CONCLUSION: Among both physicians and hospitals, higher pneumonia volume is associated with reduced adherence to selected guideline recommendations and no measurable improvement in patient outcomes.

Use of antimicrobial prophylaxis for major surgery: baseline results from the National Surgical Infection Prevention Project.

HYPOTHESIS: Surgical site infections (SSIs) are a major contributor to patient injury, mortality, and health care costs. Despite evidence of effectiveness of antimicrobials to prevent SSIs, previous studies have demonstrated inappropriate timing, selection, and excess duration of administration of antimicrobial prophylaxis. We herein describe the use of antimicrobial prophylaxis for Medicare patients undergoing major surgery. DESIGN: National retrospective cohort study with medical record review. SETTING: Two thousand nine hundred sixty-five acute-care US hospitals. PATIENTS: A systematic random sample of 34,133 Medicare inpatients undergoing coronary artery bypass grafting; other open-chest cardiac surgery (excluding transplantation); vascular surgery, including aneurysm repair, thromboendarterectomy, and vein bypass operations; general abdominal colorectal surgery; hip and knee total joint arthroplasty (excluding revision surgery); and abdominal and vaginal hysterectomy from January 1 through November 30, 2001. MAIN OUTCOME MEASURES: The proportion of patients who had parenteral antimicrobial prophylaxis initiated within 1 hour before the surgical incision; the proportion of patients who were given a prophylactic antimicrobial agent that was consistent with currently published guidelines; and the proportion of patients whose antimicrobial prophylaxis was discontinued within 24 hours after surgery. RESULTS: An antimicrobial dose was administered to 55.7% (95% confidence interval [CI], 54.8%-56.6%) of patients within 1 hour before incision. Antimicrobial agents consistent with published guidelines were administered to 92.6% (95% CI, 92.3%-92.8%) of the patients. Antimicrobial prophylaxis was discontinued within 24 hours of surgery end time for only 40.7% (95% CI, 40.2%-41.2%) of patients. CONCLUSION: Substantial opportunities exist to improve the use of prophylactic antimicrobials for patients undergoing major surgery.

Blood culture and susceptibility results and allergy history do not influence fluoroquinolone use in the treatment of community-acquired pneumonia.

STUDY OBJECTIVE: To determine the influence of blood culture and susceptibility results and antimicrobial allergy history on fluoroquinolone use in the treatment of community-acquired pneumonia. DESIGN: Retrospective analysis of medical records. SETTING: Centers for Medicare and Medicaid Services, Seattle, Washington. PATIENTS: A total of 10,275 Medicare beneficiaries hospitalized with the diagnosis of pneumonia received antimicrobial treatment within 24 hours of admission. Of these patients, 288 had blood cultures positive for pneumococcus and were matched one-to-one with patients with negative blood and sputum cultures. MEASUREMENTS AND MAIN RESULTS: Antimicrobial use at the beginning and end of hospitalization, culture and susceptibility results, and patient allergies were recorded retrospectively and compared between two matched groups: patients with blood cultures positive for Streptococcus pneumoniae and those whose blood and sputum cultures were negative. Neither culture and susceptibility results nor allergy history affected the rate of fluoroquinolone use. Despite infection due to penicillin-susceptible pneumococci and no penicillin allergy, patients received therapy with fluoroquinolones (26.7%) as frequently as those with culture-negative pneumonia (34.9%; p=0.401). CONCLUSION: Fluoroquinolones are prescribed despite microbiologic confirmation of penicillin-susceptible pneumococcal pneumonia in the absence of penicillin allergy. These prescribing patterns may contribute to selection pressure associated with fluoroquinolone-resistant gram-positive and gram-negative bacteria.

Antimicrobial prophylaxis for surgery: an advisory statement from the National Surgical Infection Prevention Project.

In January 2003, leadership of the Medicare National Surgical Infection Prevention Project hosted the Surgical Infection Prevention Guideline Writers Workgroup meeting. The objectives were to review areas of agreement among the published guidelines for surgical antimicrobial prophylaxis, to address inconsistencies, and to discuss issues not currently addressed. The participants included authors from most of the published North American guidelines for antimicrobial prophylaxis and several specialty colleges. The workgroup reviewed currently published guidelines for antimicrobial prophylaxis. Nominal group process was used to draft a consensus paper that was widely circulated for comment. The consensus positions of the workgroup include that infusion of the first antimicrobial dose should begin within 60 minutes before surgical incision and that prophylactic antimicrobial agents should be discontinued within 24 hours of the end of surgery. This advisory statement provides an overview of other issues related to antimicrobial prophylaxis including specific suggestions regarding antimicrobial selection.

Timing of antibiotic administration and outcomes for Medicare patients hospitalized with community-acquired pneumonia.

BACKGROUND: Pneumonia accounts for more than 600 000 Medicare hospitalizations yearly. Guidelines have recommended antibiotic treatment within 8 hours of arrival at the hospital. METHODS: We performed a retrospective study using medical records from a national random sample of 18 209 Medicare patients older than 65 years who were hospitalized with community-acquired pneumonia from July 1998 through March 1999. Outcomes were severity-adjusted mortality, readmission within 30 days of discharge, and length of stay (LOS). RESULTS: Among 13 771 (75.6%) patients who had not received outpatient antibiotic agents, antibiotic administration within 4 hours of arrival at the hospital was associated with reduced in-hospital mortality (6.8% vs 7.4%; adjusted odds ratio [AOR], 0.85; 95% confidence interval [CI], 0.74-0.98), mortality within 30 days of admission (11.6% vs 12.7%; AOR, 0.85; 95% CI, 0.76-0.95), and LOS exceeding the 5-day median (42.1% vs 45.1%; AOR, 0.90; 95% CI, 0.83-0.96). Mean LOS was 0.4 days shorter with antibiotic administration within 4 hours than with later administration. Timing was not associated with readmission. Antibiotic administration within 4 hours of arrival was documented for 60.9% of all patients and for more than 50% of patients regardless of hospital characteristics. CONCLUSIONS: Antibiotic administration within 4 hours of arrival was associated with decreased mortality and LOS among a random sample of older inpatients with community-acquired pneumonia who had not received antibiotics as outpatients. Administration within 4 hours can prevent deaths in the Medicare population, offers cost savings for hospitals, and is feasible for most inpatients.

Failure to vaccinate Medicare inpatients: a missed opportunity.

BACKGROUND: Hospitalized elderly patients are at risk for subsequent influenza and pneumococcal disease. Despite this risk, they are often not vaccinated in this setting. METHODS: We reviewed the medical records of a national sample of 107 311 fee-for-service Medicare patients, 65 years or older, discharged from April 1, 1998, through March 31, 1999, with a principal diagnosis of acute myocardial infarction, heart failure, pneumonia, or stroke. We linked patient identifiers to Medicare Part B claims to identify influenza and pneumococcal vaccines paid for before, during, or after hospitalization. The main outcome measures were documentation by chart review or paid claim of influenza or pneumococcal vaccination. RESULTS: Of the 104 976 patients with a single hospitalization, 35 169 (33.5%; 95% confidence interval [CI], 33.2%-33.8%) received pneumococcal vaccination prior to admission, 444 (0.4%; 95% CI, 0.4%-0.5%) were vaccinated in the hospital, and 1076 (1.0%; 95% CI, 1.0%-1.1%) were vaccinated within 30 days of discharge. In the subgroup of 40 488 patients discharged from October through December, 12 782 (31.6%; 95% CI, 31.1%-32.0%) received influenza vaccination prior to admission, 755 (1.9%; 95% CI, 1.7%-2.0%) were vaccinated in the hospital, and 4302 (10.6%; 95% CI, 10.3%-10.9%) were vaccinated after discharge. Of patients who were unvaccinated prior to admission, 97.3% (95% CI, 97.1%-97.5%) did not receive influenza vaccine and 99.4% (95% CI, 99.3%-99.4%) did not receive pneumococcal vaccine before hospital discharge. CONCLUSION: National recommendations for inpatient vaccination against influenza and pneumococcal disease are not being followed for the vast majority of eligible Medicare patients admitted to the hospital.

Antimicrobial prophylaxis for surgery: an advisory statement from the National Surgical Infection Prevention Project.

In January 2003, leadership of the Medicare National Surgical Infection Prevention Project hosted the Surgical Infection Prevention Guideline Writers Workgroup (SIPGWW) meeting. The objectives were to review areas of agreement among the most-recently published guidelines for surgical antimicrobial prophylaxis, to address inconsistencies, and to discuss issues not currently addressed. The participants included authors from most of the groups that have published North American guidelines for antimicrobial prophylaxis, as well as authors from several specialty colleges. Nominal group process was used to draft a consensus paper that was widely circulated for comment. The consensus positions of SIPGWW include that infusion of the first antimicrobial dose should begin within 60 min before surgical incision and that prophylactic antimicrobials should be discontinued within 24 h after the end of surgery. This advisory statement provides an overview of other issues related to antimicrobial prophylaxis, including specific suggestions regarding antimicrobial selection.

Effects of previous influenza vaccination on subsequent readmission and mortality in elderly patients hospitalized with pneumonia.

PURPOSE: To determine the effect of influenza vaccination on mortality and hospital readmission rates following discharge of elderly patients admitted with pneumonia. METHODS: We reviewed the medical records of 12,566 randomly selected Medicare beneficiaries hospitalized for pneumonia from October 1 through December 31, 1998, to assess mortality and hospital readmission rates from the date of discharge through the influenza season, May 1, 1999. Patients were grouped based on vaccination status: before hospitalization, during hospitalization, or unknown (no evidence of vaccination). RESULTS: Severity-adjusted mortality rates were 22.4% (95% confidence interval [CI]: 14.4% to 29.7%) for the vaccination before hospitalization group, 26.4% (95% CI: 20.4% to 31.9%) for the in-hospital vaccination group, and 29.4% (95% CI: 28.1% to 30.6%) for the unknown vaccination status group. Patients vaccinated before hospitalization had significantly lower mortality than did patients with unknown vaccination status (hazard ratio [HR] = 0.65; 95% CI: 0.59 to 0.70; P <0.0001). Adjusted readmission rates were 42.6% (95% CI: 40.0% to 45.1%) for the vaccination before hospitalization group, 40.0% (95% CI: 33.2% to 46.1%) for the in-hospital vaccination group, and 44.8% (95% CI: 43.3% to 46.4%) for the unknown vaccination status group. Patients vaccinated before hospitalization had significantly lower readmission rates than patients with unknown vaccination status (HR = 0.92; 95% CI: 0.87 to 0.98; P = 0.009). CONCLUSION: Influenza vaccination before hospitalization was effective in decreasing subsequent mortality and hospital readmission in elderly patients with pneumonia.

Office evaluation and treatment of elderly patients with acute bronchitis.

OBJECTIVES: To assess the office evaluation of seniors with uncomplicated acute bronchitis and to determine the association between elements of the clinical evaluation and antibiotic prescribing decisions. DESIGN: Cross-sectional chart review. SETTING: Seventy-seven community-based office practices in the Denver metropolitan area. PARTICIPANTS: Elderly fee-for-service Medicare patients. MEASUREMENTS: Medicare administrative data to identify patients with acute bronchitis; medical record review to confirm the diagnosis and record other clinical data. RESULTS: Of 198 elderly patients with acute bronchitis, the mean age+/-standard deviation was 76+/-8.6; 53% had at least one comorbid condition. Clinically important vital signs were frequently not recorded; temperature was missing from 34% of charts and pulse from 50% of charts. When recorded, significant vital sign abnormalities were uncommon, with 7% having a temperature of 100 degrees F and 8% having a pulse of 100 beats per minute or greater. However, antibiotics were prescribed to 83% of patients, with more than half of these prescriptions being for extended-spectrum antibiotics. Treatment with antibiotics was more common in men than women (92% vs 78%, P=.007) but was not associated with clinical factors including vital sign measurement, vital sign results, chest radiography, patient age, duration of illness, or the presence of comorbidities. CONCLUSION: The vast majority of seniors with acute bronchitis are treated with antibiotics, regardless of patient characteristics or the type of evaluation received. Reducing inappropriate antibiotic use in seniors with acute bronchitis may depend on improving the evaluation of these patients and encouraging clinicians to act appropriately on the results.

Antibiotic treatment of acute respiratory tract infections in the elderly: effect of a multidimensional educational intervention.

OBJECTIVES: : To measure and improve antibiotic use for acute respiratory tract infections (ARIs) in the elderly. DESIGN: : Prospective, nonrandomized controlled trial. SETTING: : Ambulatory office practices in Denver metropolitan area (n=4 intervention practices; n=51 control practices). PARTICIPANTS: : Consecutive patients enrolled in a Medicare managed care program who were diagnosed with ARIs during baseline (winter 2000/2001) and intervention (winter 2001/2002) periods. A total of 4,270 patient visits were analyzed (including 341 patient visits in intervention practices). INTERVENTION: : Appropriate antibiotic use and antibiotic resistance educational materials were mailed to intervention practice households. Waiting and examination room posters were provided to intervention office practices. MEASUREMENTS: : Antibiotic prescription rates, based on administrative office visit and pharmacy data, for total and condition-specific ARIs. RESULTS: : There was wide variation in antibiotic prescription rates for ARIs across unique practices, ranging from 21% to 88% (median=54%). Antibiotic prescription rates varied little by patient age, sex, and underlying chronic lung disease. Prescription rates varied by diagnosis: sinusitis (69%), bronchitis (59%), pharyngitis (50%), and nonspecific upper respiratory tract infection (26%). The educational intervention was not associated with greater reduction in antibiotic prescription rates for total or condition-specific ARIs beyond a modest secular trend (P=.79). CONCLUSION: : Wide variation in antibiotic prescription rates suggests that quality improvement efforts are needed to optimize antibiotic use in the elderly. In the setting of an ongoing physician intervention, a patient education intervention had little effect. Factors other than patient expectations and demands may play a stronger role in antibiotic treatment decisions in elderly populations.

Factors affecting QuickVue Influenza A + B rapid test performance in the community setting.

Rapid diagnosis of influenza can facilitate timely clinical management. We evaluated the performance of the QuickVue Influenza A + B test (Quidel, San Diego, CA) in a community setting and investigated the factors affecting test sensitivity. We recruited 1008 subjects from 30 outpatient clinics in Hong Kong between February and September 2007. Each subject provided 2 pooled pairs of nose and throat swabs; 1 pair was tested by the QuickVue rapid test on site, and the other pair was sent to a laboratory for reference tests. Among 998 enrolled subjects with valid results, the rapid test had overall sensitivity of 0.68 and specificity of 0.96 compared with viral culture. Sensitivity for both influenza A and B was significantly higher for specimens with viral loads greater than 5 log(10) copies/mL. The QuickVue Influenza A + B test has similar sensitivity in point-of-care community settings to more controlled conditions.

Preliminary findings of a randomized trial of non-pharmaceutical interventions to prevent influenza transmission in households.

BACKGROUND: There are sparse data on whether non-pharmaceutical interventions can reduce the spread of influenza. We implemented a study of the feasibility and efficacy of face masks and hand hygiene to reduce influenza transmission among Hong Kong household members. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cluster randomized controlled trial of households (composed of at least 3 members) where an index subject presented with influenza-like-illness of <48 hours duration. After influenza was confirmed in an index case by the QuickVue Influenza A+B rapid test, the household of the index subject was randomized to 1) control or 2) surgical face masks or 3) hand hygiene. Households were visited within 36 hours, and 3, 6 and 9 days later. Nose and throat swabs were collected from index subjects and all household contacts at each home visit and tested by viral culture. The primary outcome measure was laboratory culture confirmed influenza in a household contact; the secondary outcome was clinically diagnosed influenza (by self-reported symptoms). We randomized 198 households and completed follow up home visits in 128; the index cases in 122 of those households had laboratory-confirmed influenza. There were 21 household contacts with laboratory confirmed influenza corresponding to a secondary attack ratio of 6%. Clinical secondary attack ratios varied from 5% to 18% depending on case definitions. The laboratory-based or clinical secondary attack ratios did not significantly differ across the intervention arms. Adherence to interventions was variable. CONCLUSIONS/SIGNIFICANCE: The secondary attack ratios were lower than anticipated, and lower than reported in other countries, perhaps due to differing patterns of susceptibility, lack of significant antigenic drift in circulating influenza virus strains recently, and/or issues related to the symptomatic recruitment design. Lessons learnt from this pilot have informed changes for the main study in 2008. TRIAL REGISTRATION: ClinicalTrials.gov NCT00425893 HKClinicalTrials.com HKCTR-365.