Pandemic influenza-focus on inpatient issues

Pandemic influenza-focus on inpatient issuesSusan M. Kellie, MD, MPHAssociate Professor of MedicineDivision of Infectious DiseasesHospital Epidemiologist, UNMHSC and NMVAHCS

Talk outlineCurrent epidemiologyPotential surge for inpatient careSpectrum of disease and complicationsTesting and treatmentInfection control in the hospitalHealthcare worker health issuesContingency planning

Number of isolates Influenza A by week 2009-Tricore lab, NM

Case rate by age group-US data on around 35k confirmed cases

Hospitalization rates by age group

Deaths-numbers by age group

Age distribution of current cases-NMTricore requests for virus detection 9/5-9/11/09536 requests, 80 positives3 adenovirus77 Influenza A-all from previous week confirmed as H1N1Age# of isolates0-2: 33-5:126-11: 2212-18: 2119-64: 15>65: 4

FluSurge 2.0 assumptionsNo. 1 Average length of non-ICU hospital stay for influenza-related illness is 5 days. No. 2 Average length of ICU stay for influenza-related illness is 10 days. No. 3 Average length of ventilator usage for influenza-related illness is 10 days. No. 4 Average proportion of admitted influenza patients will need ICU care is 15%. No. 5 Average proportion of admitted influenza patients will need ventilators is 7.5%. No. 6 Average proportion of influenza deaths assumed to be hospitalized is 70%. No. 7 Daily percentage increase in cases arriving compared to previous day is 3%. 4

Disease spectrumMost disease is mild and does not require medical attentionPatients should be educated to do self-care at homeAll persons should be aware of the danger signs shortness of breath, either during physical activity or while resting difficulty in breathing turning blue bloody or coloured sputum chest pain altered mental status high fever that persists beyond 3 days low blood pressure.

Clinical course of more severe diseaseWHO states 40% of patients with severe manifestations of pandemic influenza do not have underlying risk factors

Rapid progression to viral pneumonia at the onset of symptomsDeterioration at day 4-5 of symptoms with viral pneumonia and MODSBacterial superinfection not described in US severe casesSome descriptions of bloody mucus plugging requiring therapeutic bronchoscopy

Groups at risk of severe diseasePregnant women and those in the immediate post-partum periodChildren under 4Immunocompromised and those with underlying cardiopulmonary, metabolic, liver, renal conditionsOlder children with neurodevelopmental delay-only group described so far with substantial rates of bacterial superinfectionObesity may be a risk factor? Due to other underlying conditions

MMWR Dispatch July 10, 2009/58(Dispatch):1-4Intensive Care patients with Severe Novel Influenza A (H1N1) Virus Infection-Michigan, June 200910 patients with H1N1 and ARDS9 had BMI >30, 7 had BMI>40Other RF: asthma, asthma plus smoking, granulomatous chronic lung disease5 had PE, 9 had MODS3 diedDFA for influenza was negative in all 10, viral culture was positive in 210 were confirmed by PCR of respiratory specimens

Complicated or severe influenza

Presentations:clinical and/or radiological signs of pneumonia, CNS findings (e.g. encephalopathy), severe dehydration or secondary complications such as renal failure, multiorgan failure, and septic shock. Other complications can include musculoskeletal (rhabdomyolysis) and cardiac (myocarditis).

Exacerbation of underlying chronic disease

Any condition requiring hospital admission for clinical management.

Signs and symptoms of progressive disease

Patients who present initially with uncomplicated influenza may progress to more severe disease. Progression can be rapid. Indicators include respiratory, CNS deterioration or indicators of severe dehydration, hypotensioni.e. meet criteria for sepsis, SIRS, MODS

Preventing bacterial pneumoniaPneumovax is now indicated for all asthmatics and current smokers age 19 and up

Be aware of MRSA/ MSSA necrotizing pneumonia following or concurrent with influenzaPresents with severe pleuritic chest pain, purulent bloody sputum, toxic patients

Neuro manifestations of influenza in adults-per Dr. Larry DavisMost common is severe headache, fever, and meningismus mimicking an acute meningitis. However, the CSF is normal with no cells. It is self limited. Myalgias of the posterior neck muscles simulate the meningismus.

Second most common is pt with high fever, headache, myalgias, and confusion looking like an acute encephalopathy. MRI is normal. Self limited, improves quickly

The third most common is seizures. Any high fever can trigger a seizure and influenza can. In those from Mexico, consider underlying neurocysticercosis.

Uncommon but does occur are patients with Reyes syndrome

Another group is the influenza ADEM where the encephalopathy has focal neurologic signs, and the MRI shows patchy white matter lesions.

Finally is the influenza patient with focal myositis. The muscle is painful and biopsies have shown actual fiber necrosis and inflammation.CPK is elevated

H1N1 2009 influenza virus during pregnancy in the USA-Lancet online July 29, 2009From April 15-May 18, 2009, 34 confirmed or probable cases of H1N1 in pregnant women were reported to CDC from 13 states. 11 (32%) were admitted to hospital. Rate of admission was 0.32 per 100,000 pregnant women at risk vs 0.076 per 100,000 general population6 of 45 deaths from April 15 to June 16 were in pregnant women. As more deaths accrued over the following week, this ratio dropped to 7 out of 87 deaths.

Recent case at UNM21 year old woman with only PMHx recent pregnancy and C-section-not within last month4 days of coryza, cough and feverPresented to another ED hypotensive and hypoxemicIntubated, flown to UNMH.Died after 11 days in ICU with refractory ARDS

Emerging complicationsPulmonary embolisms in non-hospitalized and hospitalized patients

Respiratory decompensation in ventilated patients due to plugging with bloody mucus

Myositis

Figure 3. Distribution of Guillain-Barre syndrome episodes in 90-day intervals around the date of influenza-like illness, UK 1990-2005. Stowe et al. Am J Epidemiol 2009; 169: 382-8

Influenza causes GBS

Testing/surveillanceAs disease activity increases, it is 30-70% likely that influenza-like illness (i.e. fever plus sore throat and/or cough) is influenza-more sensitive the younger the patient is. Influenza H1N1 is almost 100% of circulating strainsTesting should be limited to hospitalized patientsSpecific PCR testing for H1N1 will be performed at state lab on admitted patients for epidemiologic purposes

Exact mechanics of testing still to be decidedCurrently Tricore forwards all positives to SLD for PCR-requires extensive form to be filled outState now wants all negative swabs also-will match to admission list for respiratory diseases (?)No feedback loop to infection control on previously unidentified cases (rapid neg, PCR positive)-these are called to provider/patientTricore now validating independent PCR with SLD

Test all patients admitted with or developing while in hospitalNMDOH : All hospitalized patients meeting any of the following criteria are considered by NMDOH to be possible influenza cases and should have a specimen sent to SLD for influenza PCR testing, regardless of whether other influenza testing has been ordered (e.g., a rapid influenza diagnostic test):

*Influenza or rule-out influenza*Influenza-like illness (i.e., fever 100 degrees Fahrenheit or higher, and cough, and/or sore throat) *Pneumonia or rule-out pneumonia*Bronchiolitis*Exacerbation of underlying pulmonary disease (e.g., asthma, cystic fibrosis, COPD)*Fever of unknown origin*Cough*Dyspnea/shortness of breath/respiratory distress*CHF, or CHF exacerbation, associated with fever or with unclear etiology

Added by SK_ARDS, respiratory failure

*Any of the following testing/treatment events:

*Any influenza test ordered on an inpatient*Any influenza antiviral medication/s {e.g., Tamiflu (oseltamavir), Relenza (zanamavir), Symmetrel (amantadine), Flumadine (rimantadine)} ordered for an inpatient

OseltamivirNew Mexico has 350,000 coursesEnough to treat 1/3 to 1/2 of those who might become illPrioritize those admitted to hospital with severe/complicated influenzaPersons at high risk of complications of influenza-young children, pregnant women and those with underlying conditionsProphylax persons at high risk post-exposure

WHO classificationUncomplicated influenza Influenzalike illness symptoms: fever, cough, sore throat, rhinorrhea, headache, muscle pain, malaise, but no shortness of breath, no dyspnoea. Patients may present with some or all of these symptoms. Gastrointestinal illness may also be present, such as diarrhoea and/or vomiting, especially in children, but without evidence of dehydration.

Signs and symptoms of progressive disease

Patients who present initially with uncomplicated influenza may progress to more severe disease. Progression can be rapid. Indicators include respiratory, CNS deterioration or indicators of severe dehydration, hypotensioni.e. meet criteria for sepsis, SIRS, MODS

TreatmentTreat serious /hospitalized cases immediatelyOseltamivir can significantly reduce the risk of pneumonia (a leading cause of death for both pandemic and seasonal influenza) and the need for hospitalization. (usual dose 75mg po bid for 5 days, reduce by 50% for creatinine clearance under 30ml/min)

For patients with severe or deteriorating illness, treatment should be provided even if started later. Where oseltamivir is unavailable or cannot be used for any reason, zanamivir may be given.

Patients with underlying medical conditions that increase the risk of more severe disease, should also receive treatment as soon as possible after symptom onset, without waiting for the results of laboratory tests. Children under4Pregnant women or those in the immediate post-partum periodAll patients with underlying conditionsALSO PROPHYLAX THIS GROUP AND EXPOSED HCWsProphylaxis dose oseltamivir 75mg po qd for 10 d

Treatment in severe diseaseIn ventilated patients, some clinicians have used double dose oseltamivir 150mg po bid Based on H5N1 experience and fear that diarrhea will interfere with absorptionDuration of treatment can be longer-no data in severely ill patients

Investigational drug: peramivir-Dr. Goade is PI,Intravenous neuraminidase inhibitor, final criteria for study pending, open label

Employee healthEmployees with influenza-like illness must call supervisor and stay off work for either 7 days or 24 hours afebrile off all antipyretics, whichever is longerDoctors note will not be requiredVacation time will not be takenTreatment will be dispensed to employees at higher risk of complications-send in family with your ID. Lobocare clinic will be site of care for sick UNM employees and referral site for UH employeesNo work restrictions are advised for employees at higher risk e.g. pregnant workers

Infection control-see WHO checklistHICPAC recommendations:Standard and droplet (surgical mask) precautions will be used.N95 masks will be reserved for the following aerosol-generating procedures on patients with ILI:Intubation/extubationCPR with emergency intubation and/or chest compressionsOpen suctionBronchoscopy

Infection control in 1918Basic respiratory hygiene and droplet precaution measures

None of my classmates died and very few became ill. Perhaps the masks, gowns and handwashing did more to protect us than we had a right to expect. Certainly, with death all around us, we had every encouragement to be as careful as we could, but we were so busy and so tired that we forgot about precautions, and patient after patient coughed into our faces as we tended to their needs.Starr. Influenza in 1918: recollections of the epidemic in Philadelphia. Ann Intern Med 2006: 145:138-40.

Visitors: Some restrictions applyBefore entering the room:Hand HygieneDon Surgical MaskDon Gown, Gloves and Eye Protection depending on task and risk of exposure to body fluidsExpanded Precautions indicated for aerosol generating procedures turn sign overOn exit from room:Remove and Discard PPEHand HygieneDisinfect all shared equipment.

Droplet PrecautionsPlease see a nurse for instructions before entering the room. Surgical mask required with hand hygiene on entry and exit. Protective equipment is not available for children