Public Health Aspects of H1N1

VIHA Family Practice CouncilSeptember 17, 2009

Reassortments leading to the evolution of 2009 Influenza A H1N1

Trifonov, NEJM, July 2009

Clinical Presentation of Initial US H1N1 Cases

0 20 40 60 80 100

vomit

diarrhea

sore throat

cough

fever

percent of cases

Influenza Like Illness Clinical Case Definition

• Fever(*) AND Cough• AND at least one of:

– Sore throat– coryza– Myalgia– Arthralgia– Diarrhea/vomiting

*Fever may be absent in young children and seniors

Surveillance Plan for H1N1

• Detailed data collection from all hospitalized cases• Lab based surveillance of all submitted specimens• Sentinel physicians• MSP data monitoring• Reporting of high absenteeism in schools/daycares• Active follow up with remote First Nations

communities

H1N1 Vaccine

• Produced by GlaxoSmithKline• Adjuvanted (AS03) single Ag, split virus • Initial trials safe and immunogenic after

single dose (similar vaccines from other manufactures showing similar results)

• Initial shipments expected in mid- November; then weekly for about 2 months

H1N1 Vaccine Priority Groups– persons with chronic medical conditions– pregnant women– children 6 months to less than 5 years of age– persons residing in remote and isolated settings or

communities– health care workers involved in pandemic response or

who deliver essential health services– household contacts or caregivers of those at high risk

who cannot be immunized– populations otherwise identified as high risk

• There will be sufficient H1N1 vaccine available in Canada for everyone that needs and wants to be immunized. No one will be left out.

H1N1 Vaccine Delivery

• Expected to start in mid-November• Physician and public health delivered

– Physicians will have a critical role in providing to their patients in a timely way

• 10 dose vials– e.g. could plan for 10 patients in ½ hour block

• IM injection (likely single dose)• Further information including ordering

forms will be sent by mail in October.

Tamiflu

• Commercial supply currently available through community pharmacies

• Provincial stockpile to be released to community pharmacies Oct 1.

• Available with physician prescription– Consider providing high risk patients a

prescription in advance that could be filled during fall if they develop influenza

Tamiflu Indictions• Early treatment of influenza in:

– patients with underlying conditions: Pregnancy, respiratory, cardiovascular disease, diabetes, obesity, immunocompromised

– Children 2 years and under– *Aboriginal people living on reserve

• Treatment of severe influenza cases– (severity may be indicated by deterioration in

condition with dyspnea, tacchypnea, reduced oxygen sats, hypotension)

Tamiflu dosing

H1N1 and Schools

• Schools can facilitate virus amplification• However, based on mild virus profile,

closures of schools are not warranted.• Instead, approach is:

– Attempt to exclude those with influenza until recovered

– Strong emphasis on hygeine and cough etiquette

– Emphasis on cleaning common surfaces