This report provides an update to the international situation as of October 2, 2009. As of October 2, 2009, the World Health Organization (WHO) regions have reported over 343,298 laboratory-confirmed cases of 2009 H1N1 with at least 4,108 deaths, which is an increase of at least 24,373 cases and 191 deaths since September 20.

Centers for Disease Control and Prevention released a report that stated swine flu is “widespread in 27 states, and outpatient visits for influenza symptoms are above normal everywhere but New England.” In fact, during September, there were 16,174 hospitalizations for swine flu across the US with 1,379 flu-related deaths, of which most were swine flu-related and 11 of them pediatric swine flu deaths

Systematic Review: Safety and Efficacy of Extended-Duration Antiviral
Chemoprophylaxis Against Pandemic and Seasonal Influenza
Nayer Khazeni, Dena M. Bravata, Jon-Erik C. Holty, Timothy M. Uyeki,
Christopher D. Stave, and Michael K. Gould
Ann Intern Med 2009;151 464-473 Open Access
http://www.annals.org/cgi/content/abstract/151/7/464?etoc

Full study:  http://www.annals.org/cgi/content/full/151/7/464

Background: Neuraminidase inhibitors (NAIs) are stockpiled internationally for extended use in an influenza pandemic.

Purpose: To evaluate the safety and efficacy of extended-duration (>4 weeks) NAI chemoprophylaxis against influenza.

Data Sources: Studies published in any language through 11 June 2009 identified by searching 10 electronic databases and 3 trial registries.

Study Selection: Randomized, placebo-controlled, double-blind human trials of extended-duration NAI chemoprophylaxis that reported outcomes of laboratory-confirmed influenza or adverse events.

Data Extraction: 2 reviewers independently assessed study quality and abstracted information from eligible studies.

Data Synthesis: Of 1876 potentially relevant citations, 7 trials involving 7021 unique participants met inclusion criteria. Data were pooled by using random-effects models. Chemoprophylaxis with NAIs decreased the frequency of symptomatic influenza (relative risk [RR], 0.26 [95% CI, 0.18 to 0.37]; risk difference [RD], –3.9 percentage points [CI, –5.8 to –1.9 percentage points]) but not asymptomatic influenza (RR, 1.03 [CI, 0.81 to 1.30]; RD, –0.4 percentage point [CI, –1.6 to 0.9 percentage point]). Adverse effects were not increased overall among NAI recipients (RR, 1.01 [CI, 0.94 to 1.08]; RD, 0.1 percentage point [CI, –0.2 to 0.4 percentage point]), but nausea and vomiting were more common among those who took oseltamivir (RR, 1.48 [CI, 1.86 to 2.33]; RD, 1.7 percentage points [CI, 0.6 to 2.9 percentage points]). Prevention of influenza did not statistically significantly differ between zanamivir and oseltamivir.

Limitations: All trials were industry-sponsored. No study was powered to detect rare adverse events, and none included diverse racial groups, children, immunocompromised patients, or individuals who received live attenuated influenza virus vaccine.

Conclusion: Extended-duration zanamivir and oseltamivir chemoprophylaxis seems to be highly efficacious for preventing symptomatic influenza among immunocompetent white and Japanese adults. Extended-duration oseltamivir is associated with increased nausea and vomiting. Safety and efficacy in several subpopulations that might receive extended-duration influenza chemoprophylaxis are unknown.

Facemasks and Hand Hygiene to Prevent Influenza Transmission in Households:
A Cluster Randomized Trial
Benjamin J. Cowling, Kwok-Hung Chan, Vicky J. Fang, Calvin K.Y. Cheng, Rita
O.P. Fung, Winnie Wai, Joey Sin, Wing Hong Seto, Raymond Yung, Daniel W.S.
Chu, Billy C.F. Chiu, Paco W.Y. Lee, Ming Chi Chiu, Hoi Che Lee, Timothy M.
Uyeki, Peter M. Houck, J. S. Malik Peiris, and Gabriel M. Leung
Ann Intern Med 2009;151 437-446 Open Access
http://www.annals.org/cgi/content/abstract/151/7/437?etoc

Full study:  http://www.annals.org/cgi/content/full/151/7/437

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.

Nebivolol: The Somewhat-Different β-Adrenergic Receptor Blocker

Although its clinical use in Europe dates almost 10 years, nebivolol is a β-blocker that has been only recently introduced in the U.S. market. Like carvedilol, nebivolol belongs to the third generation of β-blockers, which possess direct vasodilator properties in addition to their adrenergic blocking characteristics. Nebivolol has the highest β₁-receptor affinity among β-blockers and, most interestingly, it substantially improves endothelial dysfunction via its strong stimulatory effects on the activity of the endothelial nitric oxide synthase and via its antioxidative properties. Because impaired endothelial activity is attributed a major causal role in the pathophysiology of hypertension, coronary artery disease, and congestive heart failure, the endothelium-agonistic properties of nebivolol suggest that this drug might provide additional benefit beyond β-receptor blockade. Although lesser β-blocker–related side effects have been reported in patients with chronic obstructive pulmonary disease or impotence taking nebivolol, side effects and contraindications overlap those of other β-blockers. Clinically, this compound has been proven to have antihypertensive and anti-ischemic effects as well as beneficial effects on hemodynamics and prognosis in patients with chronic congestive heart failure. Further studies are now necessary to compare the benefit of nebivolol with that of other drugs in the same class and, most importantly, its prognostic impact in patients with hypertension.

Link to full story:  http://www.cidrap.umn.edu/cidrap/content/influenza/swineflu/news/oct0509firstdoses.html

Oct 5, 2009 (CIDRAP News) – “The nation’s first doses of the pandemic H1N1 vaccine were administered today, mainly to a limited group of healthcare workers and emergency medical service workers, while some physicians’ offices fielded calls about when the vaccine would be more widely available.

Federal, state, and local officials were on hand to witness the events today at medical facilities in Memphis and Indianapolis. The very first doses were given to healthcare workers at Le Bonheur Children’s Medical Center in Memphis, according to a press release from the hospital.

Doctors, nurses, and respiratory therapists who work in the hospital’s emergency department and intensive care units were in the first group to receive the live attenuated nasal mist form of the H1N1 flu vaccine, made by MedImmune. Pediatric physicians, residents, and infectious disease specialists were also among Le Bonheur’s first recipients.

About 150 workers lined up to receive the vaccine……”