Angela J. Peck

Lower respiratory tract infections among american Indian and Alaska Native children and the general population of U.S. Children.

Background and Objective: Lower respiratory tract infections (LRTIs) cause substantial childhood morbidity. This study characterizes and compares LRTI-associated morbidity among American Indian/Alaska Native (AI/AN) children and the general population of U.S. children. Methods: Hospitalization and outpatient records with a diagnosis indicating LRTIs were evaluated for children aged younger than 5 years during 1990–2001. Results: For 1999–2001, the LRTI-associated hospitalization rate was significantly higher for AI/AN children than for U.S. children (116.1 versus 63.2/1000, respectively), with the disparity being greater for infants than for 1- to 4-year-old children. Also the rate of LRTI-associated outpatient visits among AI/AN infants was higher than that for all U.S. infants (737.7 versus 207.2/1000, respectively). LRTI hospitalization and outpatient visit rates were highest in the Alaska and Southwest Indian Health Service regions. During 1990–2001, the LRTI hospitalization rate among AI/AN infants in the Alaska region and among the general U.S. infant population increased. Bronchiolitis-associated hospitalization rates increased for AI/AN and U.S. infants, whereas the pneumonia-associated hospitalization rate decreased among AI/AN infants and remained stable among U.S. infants. Conclusions: LRTIs continue to be an important cause of morbidity in children, especially among AI/AN infants in the Alaska and Southwest regions. Strategies to reduce LRTI hospitalizations and outpatient visits are warranted for all infants, but the greatest potential impact would be among AI/AN infants.

Safety and tolerability of oseltamivir prophylaxis in hematopoietic stem cell transplant recipients: a retrospective case-control study.

BACKGROUND Oseltamivir is safe and effective in immunocompetent persons, and prophylactic use is recommended during influenza outbreaks. However, no data exist regarding the use of oseltamivir as prophylaxis among patients undergoing hematopoietic stem cell transplantation (HSCT). METHODS In January 2002, an influenza A outbreak was identified when 4 cases occurred within 1 week at an outpatient residential facility for patients undergoing HSCT. Oseltamivir prophylaxis (75 mg per day) was initiated for all asymptomatic patients living in the housing facility. Retrospectively, 45 patients (25 of whom had undergone HSCT, and 20 of whom were pre-HSCT candidates) who received oseltamivir prophylaxis were evaluated for adverse events. These 45 patients were matched 1 : 1 with control subjects who received transplants during the period 1994-2003 and did not receive prophylaxis; they were matched according to donor type, conditioning regimen, cytomegalovirus serostatus, time after HSCT, and recipient age (+/-5 years). The frequency of clinical and laboratory adverse events was determined by chart review and graded using National Cancer Institute Common Terminology Criteria. RESULTS Forty-five residents received oseltamivir for a median of 17 days (range, 10-81 days). No new cases of influenza A occurred in the facility. Seven weeks after initiation of prophylaxis, 1 resident who had been noncompliant to prophylaxis developed an influenza B infection, followed by an additional case of influenza B that occurred in a patient who had not received prophylaxis. No deaths occurred that were attributable to prophylaxis. The proportions of clinical and laboratory adverse events meeting common terminology criteria grades 2-4 or 3-4 were not significantly different between the case patients who received oseltamivir prophylaxis and control subjects. CONCLUSION Oseltamivir prophylaxis appeared to be safe and well tolerated in managing an influenza outbreak in an HSCT outpatient residence.

Two Outbreaks of Severe Respiratory Disease in Nursing Homes Associated with Rhinovirus

Objectives: To characterize illness and identify the etiology for two nursing home outbreaks of respiratory illness.

Rhinovirus as a cause of fatal lower respiratory tract infection in adult stem cell transplantation patients: a report of two cases

Respiratory failure is an important cause of morbidity and mortality among adult hematopoietic SCT (HCT) patients. Although rhinovirus is known to replicate and cause symptoms within the upper respiratory tract (URT), its potential role in lower respiratory tract (LRT) infection is controversial.1, 2 Data regarding the potential etiologic role of rhinovirus in LRT infection within the HCT population are sparse. Three previous studies of a combined 181 HCT patients identified 16 patients with respiratory failure and evidence of LRT rhinovirus.3, 4, 5 In each of these cases, however, either a copathogen was identified that likely contributed to disease or disease developed within 10 days of HCT, while patients were still suffering the effects of chemotherapy and/or radiotherapy that may have contributed to respiratory failure. We present two cases of fatal pneumonia in HCT patients likely caused by rhinovirus.

Pretransplantation respiratory syncytial virus infection: Impact of a strategy to delay transplantation

BACKGROUND Delay of hematopoietic stem cell transplantation (HSCT) has been suggested if upper respiratory tract infection (URTI) due to respiratory syncytial virus (RSV) occurs in transplantation candidates, but the efficacy of this strategy in preventing posttransplantation RSV infection is unknown. METHODS In a retrospective study, we reviewed charts of patients who underwent transplantation at Fred Hutchinson Cancer Research Center (Seattle, WA) during the period of June 1987 through December 2000 and evaluated the strategy of delaying HSCT in candidates with laboratory-confirmed RSV URTI. RESULTS Thirty-one of 37 patients had RSV URTI before conditioning, 2 (6.5%) of whom developed RSV infection after HSCT. In 6 of 37 patients, symptoms of URTI were present during the start of conditioning, but RSV virologic confirmation occurred a median of 4.5 days (range, 2-5 days) into the conditioning regimen. Conditioning was aborted for 3 of 6 patients; none had progression to RSV pneumonia. Of the 3 patients in whom HSCT proceeded as scheduled, 2 developed RSV pneumonia. Overall, RSV pneumonia occurred in 1 of 34 patients for whom HSCT was delayed, compared with 2 of 3 patients for whom there was no delay (P=.01). CONCLUSIONS In patients with pretransplantation RSV URTI, delay of HSCT was associated with a lower risk of pneumonia than was no delay. Because URTIs can progress to severe complications in patients receiving HSCTs, these results support Centers for Disease Control and Prevention/American Society of Blood and Marrow Transplantation recommendations that HSCT be delayed on the basis of symptoms of URTI rather than waiting for virologic confirmation.

SARS-associated Coronavirus Transmission, United States

To better assess the risk for transmission of the severe acute respiratory syndrome–associated coronavirus (SARS-CoV), we obtained serial specimens and clinical and exposure data from seven confirmed U.S. SARS patients and their 10 household contacts. SARS-CoV was detected in a day-14 sputum specimen from one case-patient and in five stool specimens from two case-patients. In one case-patient, SARS-CoV persisted in stool for at least 26 days after symptom onset. The highest amounts of virus were in the day-14 sputum sample and a day-14 stool sample. Residual respiratory symptoms were still present in recovered SARS case-patients 2 months after illness onset. Possible transmission of SARS-CoV occurred in one household contact, but this person had also traveled to a SARS-affected area. The data suggest that SARS-CoV is not always transmitted efficiently. Laboratory diagnosis of SARS-CoV infection is difficult; thus, sputum and stool specimens should be included in the diagnostic work-up for SARS-CoV infection.

430 OSELTAMIVIR PROPHYLAXIIS IN HEMATOPOIETIC STEM CELL TRANSPLANTATION RECIPIENTS: A CASE-CONTROL STUDY.

Background Oseltamivir is safe and effective in immunocompetent persons, and prophylactic use is recommended in the setting of an influenza outbreak; however, no data exist for use as prophylaxis among hematopoietic stem cell transplantation (HCT) candidates and recipients. Methods In January 2002, an influenza outbreak was identified when four cases occurred within 1 week at an outpatient residential facility for HCT patients. Oseltamivir prophylaxis (75 mg QD) was initiated 1 week after and given to 44 patients living in the same housing facility (25 post-HCT recipients, 19 pre-HCT candidates). Retrospectively, these 44 patients were matched 1:1 with controls transplanted between 1994 and 2003 who did not receive prophylaxis according to donor type, conditioning regimen, CMV serostatus, and recipient age ± 5 years. Frequency of clinical and laboratory adverse events (AEs) was determined by chart review and graded using the NCI Common Toxicity Criteria (CTC), grades ranging from 0 (no AE) to 5 (death). Results Forty-four patients received oseltamivir for a median of 24 days (range 15-88). Eleven pre-HCT candidates received HCT while taking prophylaxis and did not develop influenza. One of 44 patients developed influenza infection 28 days after oseltamivir was initiated; this patient had been noncompliant with dosing. No CTC grade 5 AEs occurred in either the prophylaxis or control group. The proportion of clinical AEs meeting CTC grades 2 to 4 or 3 to 4 was not significantly different between patients receiving oseltamivir and controls. There was also no difference in the proportion of laboratory abnormalities meeting CTC grades 2 to 4 between groups. Conclusion Oseltamivir prophylaxis appeared to be safe and well tolerated in managing an influenza outbreak in an HCT outpatient residential setting.