November 2, 2004 Vol. 53, No. 22

Telephone 503/731-4024 Emergencies 503/731-4030 Fax 503/731-4798 [email protected] www.dhs.state.or.us/publichealth/cdsummary/ AN EPIDEMIOLOGY PUBLICATION OF THE OREGON DEPARTMENT OF HUMAN SERVICES

LOSING OUR GRIPPE: FIGHTING FLU WITHOUT VACCINE

LTHOUGH vaccination is the This patient is already ill; how can Next, give antiviral prophylaxis most effective way to protect others be protected? Hospitalized pa- promptly to all asymptomatic residents the general public from influ- tients need to be cared for using droplet and staff to prevent influenza A infection; A 3 enza, strategies also can help— precautions (gown and gloves if soiling healthy staff should receive medication for particularly this year when our vaccine likely; wear mask if within 3 feet of two weeks after vaccination; but residents supply is half of what was expected. patient; private room if possible). and any unvaccinated staff need it until 7 This CD Summary reviews guidelines In the clinic, effective infection con- days after the outbreak is over. LTCF staff for antiviral use, flu infection control trol starts by encouraging respiratory are high priority for vaccination and pro- and “respiratory etiquette.”* The fol- etiquette in the waiting room.4 phylaxis because, if ill with influenza, lowing scenarios are intended to help • Ask patients to volunteer acute respi- they could easily infect several residents. you minimze the morbidity and mortali- ratory symptoms at check-in. The recommended agents for prophylaxis ty of influenza, given constraints of • Have tissues, receptacles, and hand- are amantadine and rimantadine, a.k.a. the vaccine and medication supply. (alcohol rubs work for influ- adamantanes. Both are active only against SCENARIO 1 enza) available in waiting areas. influenza A and can cause GI and CNS Influenza is crowding ERs, kids are • Offer masks to patients with cough, side effects; the latter occur more often home from school sick, and two of your and seat coughing patients at least 3 with amantadine (5–10%) than with colleagues are ill when an elderly patient feet from others. rimantadine (1–2%). To help preserve the with chronic obstructive pulmonary • Wallpaper your office with “Cover supply, oseltamivir is reserved for prophy- disease presents with fever and cough for Your Cough” posters to encourage laxis when adamantane-resistant virus is 1 day. He did receive influenza vaccine the practice of respiratory etiquette by suspected. Federal officials believe that this year, but you highly suspect influenza your patients at all times. plenty of adamantanes will be available A. What should you do? Some clinics may be able to arrange commercially this year. During peak flu season, many pa- “sick” and “well” waiting areas or to Third, treat suspected cases of influenza tients with typical symptoms (fever, room patients quickly to minimize the with a neuraminidase inhibitor (vide su- cough, myalgia) will have influenza; in time spent in close quarters. Consider pra) and isolate them with droplet precau- the spring or early fall flu is much less modifying appointments so individuals tions. If several residents are ill, care in a likely. In this situation, your high-risk being seen for high-risk chronic condi- cohort setting by a subset of staff may patient should be treated empirically tions are not seen at the same time as limit further spread.5 with an influenza antiviral agent for 5 those with acute fever and cough. Al- CD Summary readers know that antibi- days. Oral oseltamivir (Tamiflu®) and ways remember hand-hygiene before otics have no effect on influenza virus but inhaled zanamivir (Relenza®), both and after patient contact, and if your that bacterial pneumonia is an important neuraminidase inhibitors, are effective patient is coughing, think about wearing complication of influenza infection. Con- in decreasing the rate of influenza com- a mask yourself. These precautions may sider antibiotics if and only if you suspect plications (including hospitalization)1 also help prevent the spread of other bacterial superinfection, typically heralded and are less likely than amantadine and respiratory illnesses, such as SARS, by clinical deterioration several days into rimantadine to cause drug resistance. should it rear its ugly head in Oregon. illness. Inhaled zanamivir should not be used in SCENARIO 2 Finally, make sure your LTCF pro- this patient because it can cause bron- In December you learn of several motes respiratory etiquette, hand-hygiene, chospasm. cases of influenza A at the long-term- and common sense. Are tissues, trash All influenza antiviral agents are of care facility (LTCF) of which you are cans, sinks (or hand gel dispensers) avail- most benefit when started promptly; the the medical director. What can you do to able? Are feverish, coughing employees at efficacy of oseltamivir rapidly dwindles contain this outbreak? work? Is sick leave is provided for ill with each 12-hour delay.2 Don’t bother First, notify your local health depart- employees? Those without sick leave may starting treatment more than 48 hours ment (all outbreaks are reportable, re- need to work even when ill (not good!). after onset unless hospitalization is gardless of etiology); then, vaccinate SCENARIO 3 required or life-threatening complica- any residents or staff missed in this You care for individuals with severe tions are anticipated. year’s campaign. Vaccine distribution is immunosupression (e.g., oncology pa- * CDC’s attractive “Cover Your Cough” posters expected to continue through January tients on chemotherapy, transplant recipi- provide practical respiratory etiquette tips in your 2005. Don’t give up on your vaccination ents, HIV-infected patients, etc.) and you choice of languages. Get them at http://www.cdc.gov/ flu/protect/covercough.htm. effort until the season is over! staunchly promote annual influenza vacci- The CD Summary (ISSN 0744-7035) is published biweekly, free of CD SUMMARY charge, by the Oregon Dept. of Human Services, Office of Communicable PERIODICALS Disease and Epidemiology, 800 NE Oregon St., Portland, OR 97232 November 2, 2004 POSTAGE Periodicals postage paid at Portland, Oregon. Vol. 53, No. 22 Postmaster—send address changes to: PAID CD Summary, 800 NE Oregon St., Suite 730, Portland, OR 97232 Portland, Oregon

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nation despite your worry that your SUMMARY REFERENCES patients may not mount a protective Since we can predict neither the size 1. Kaiser L, Wat C, Mills T, et al. Impact of oseltamivir treatment on influenza-related lower respiratory tract response. How can you protect them nor the severity of the 04–05 flu season, complications and hospitalizations. Arch Intern Med once influenza is detected in the com- we promote adoption of respiratory eti- 2003;163:1667–72. 2. Aoki FY, Macleod MD, Paggiaro P, et al. Early adminis- munity? quette, clinic infection control, and rea- tration of oral oseltamivir increases the benefits of If local supplies are adequate, then sonable use (and expectations) of influenza treatment. J Antimicrob Chemother influenza antivirals. This flu season is a 2003;51:123–9. consider prophylaxis of high-risk indi- 3. Infection control measures for preventing and controlling viduals with amantadine or rimantadine good time to make them part of daily influenza transmission in healthcare facilities. CDC. practice. For additional on (Accessed November 16, 2004 at http://www.cdc.gov/flu/ for the duration of the influenza season professionals/infectioncontrol/healthcarefacilities.htm). (see http://www.cdc.gov/flu/weekly/ influenza antiviral guidelines and influen- 4. Respiratory hygiene/cough etiquette in healthcare fluactivity.htm and our website for za testing, see http:www.cdc.gov /flu/ settings. CDC. (Accessed November 16, 2004 at http:// www.cdc.gov/flu/professionals/infectioncontrol/ weekly reports). Be sure to review the professionals/treatment/ and http://www. resphygiene.htm. side-effect profiles and drug interactions cdc.gov/flu/about/qa/testing.htm. 5. Detection and control of influenza outbreaks in acute care facilities. CDC. (Accessed November 16, 2004 at http:// before prescribing. : www.cdc.gov/ncidod/hip/INFECT/flu_acute.htm#13). do not let your outpatient clinic imperil Prophylaxis and treatment of influenza A in non-pregnant patients 1 your fragile patients; minimize the threat using the infection-control suggestions Groups Drug Dose Duration in scenario #1. Limited Supply SCENARIO 4 At 4:30 pm on a Friday afternoon Treatment • High-risk persons, first 48 hours of illness 2 Oseltamivir or 75 mg p.o. b.i.d. during flu season, you get a call from an • Any person with potentially life- 5 days 3 otherwise healthy adult with acute onset threatening influenza Zanamivir 10 mg inhaled b.i.d. of fever and cough 24 hours ago. The Prophylaxis office closes in 15 minutes; should you • Outbreaks in institutions caring for Duration of elderly or other high-risk groups Amantadine or 4,5 outbreak or 7 Rimantadine 100 mg p.o. b.i.d. days after last prescribe an influenza antiviral by • Exposed high-risk persons phone? exposure Unless there is a shortage, consider Adequate Supply prompt treatment of otherwise healthy Treatment people with oseltamivir or zanamivir for Oseltamivir or 75 mg p.o. b.i.d. 2 • Healthy adults, children >1 yr 3 5 days 5 days to decrease the duration of symp- Zanamivir 10 mg inhaled b.i.d. toms (but not the already low rate of Prophylaxis • Unvaccinated high-risk persons complications) in this population. The Duration of • High-risk <2 weeks after vaccination Amantadine or 4,5 100 mg p.o. b.i.d. influenza • Immunosuppressed individuals Rimantadine 6 cost, $70 for oseltamivir and $48 for season zanamivir (according to the Sanford • Unvaccinated healthcare workers Guide) is significant; will the patient 1. All influenza antivirals are pregnancy category C. 2. For patients with CrCl 10–30 ml/min 75 mg q.d. for treatment. Minimum age 1 year.

start it soon enough to help? Seize this For children: 2 mg/kg (up to 75 mg) b.i.d.

“teachable moment” and emphasize See: http://www.cdc.gov/flu/professionals/treatment/dosage.htm. avoiding contact with high-risk persons, 3. Zanamivir minimum age 7 years; not recommended for those with underlying lung disease. 4. Amantadine 100 mg q.d. if over age 65 or CrCl<50ml/m. Children aged 1–9 years: 2.5 mg/kg staying home from work or school until (up to 75 mg) p.o. b.i.d; children 10 years and older: 100 mg p.o. b.i.d. afebrile and following respiratory eti- 5. Rimantadine 100 mg q.d. if over age 65, CrCl<10ml/min, or severe hepatic dysfunction. Children quette and hand-hygiene principles. aged 1–9 years: 2.5 mg/kg (up to 75 mg) p.o. b.i.d; children 10 years and older: 100 mg p.o. b.i.d. 6. Only for two weeks after vaccination in those expected to respond.