Birdflu Mailing List: WHO guide for H1N1 flu clinical management

[Fred H Olson (fholson]

Bill Weir wweir1 [at] gmail.com is the author of the message below.
It was posted by Fred, the list manager <fholson [at] cohousing.org>

Note that this list does not distribute attachments; the
"attached MS Word file" (actually a pdf file) is available at:

http://www.emro.who.int/csr/h1n1/pdf/clinical_management_21_5_2009.pdf

I've reformatted the text version below to improve it but the improperly
converted special characters and long URLs etc remain.

Fred

--------------------  FORWARDED MESSAGE FOLLOWS --------------------

The World Health Organization offers a guide for clinical managment of
possible H1N1 (swine) flu.  See below or, better, the attached MS Word file.

The toll of H1N1 continues to rise, with highest fatality rate still in
Mexico.  The highest number of cases so far is in US (>11,000), more than
half the global total of ~22,000, Nearby WI and IL have much higher case
rates than MN and IA.  Some authorities suggest a strong possibility of
much more virulent epidemic this coming autumn than last spring.


Suggestion:
Print the MS Word file, add a cover sheet on your congregation's letterhead,
recommending that "If you have any flu symptom, such as rapid high fever
(103+), please take a copy of this guide to your doctor in order to help
with diagnostic and treatment decisions."

Bill
Rev. Wm. M. Weir, Chair of Comte. for Emergency Preparedness, First
Unitarian Society of Minneapolis, 763-568-7022, wweir1 [at] gmail.com


===========================================================================================================================
World Health Organization

Clinical management of human infection with new influenza A (H1N1) virus:
initial guidance - 21 May 2009

Introduction

Since late April 2009, the World Health Organization (WHO) has received
reports of sustained person to person infections with a new influenza A
(H1N1) virus in Mexico and the United States. The virus has now spread to
multiple countries in Europe, the Americas and the Far East. Given the
widening risk of disease caused by this virus and its unique genetic and
antigenic characteristics as an influenza A (H1N1) variant of animal
origin, WHO, in accordance with established procedures, increased the
influenza pandemic alert level from phase 3 to phase 4 on 27 April 2009
and to phase 5 on 29 April 2009.

WHO convened a group of experts to develop the initial guidance for
clinicians on the management of human disease caused by the new influenza
A (H1N1) virus.

The advice is based on available information about the new influenza A
(H1N1) virus as well as data on the natural history, pathogenesis and
clinical characteristics of human infections caused by seasonal and avian
influenza viruses. Additional data and experience from relevant animal
models, other respiratory viral infections such as SARS (severe acute
respiratory syndrome) and associated syndromes, particularly acute
respiratory distress syndrome (ARDS) attributable to other causes, were
also reviewed. The evidence was not identified through a systematic review
process and did not include critical appraisal and grading of the quality
of the evidence. Table 1 summarizes WHO recommendations for the clinical
management of human infection with the new influenza A (H1NI) virus.

This document has been developed to meet the urgent need for guidance, and
will be updated as new information becomes available. An update on the use
of antivirals is expected before the end of June 2009.

Background

Laboratory-confirmed cases of human infection with the new influenza A
(H1N1) virus have mostly occurred in children and young adults. A spectrum
of disease ranging from non-febrile, mild upper respiratory tract illness
to severe or fatal pneumonia has been described.1 The most commonly
reported symptoms have included cough, fever, sore throat, malaise and
headache. Some cases have experienced gastrointestinal symptoms (nausea,
vomiting and/or diarrhoea). Patients who required hospitalization,
including both those who were previously healthy and those with chronic
underlying medical conditions,
~____________

1 New human influenza A (H1N1) virus infections in Mexico and other
affected countries: clinical observations. Weekly Epidemiological Record,
2009, 84(21):185?196.

have frequently experienced rapidly progressive, serious lower respiratory
tract disease. Other well-recognized influenza complications in those
seriously ill with the new influenza A (H1N1) infection have included
secondary bacterial infections, rhabdomyolysis with renal failure,
myocarditis, and worsening of underlying conditions (for example, asthma
and cardiovascular disease).

In order to improve understanding of the disease and refine optimal case
management, WHO urgently requests additional clinical and treatment data
from the regions and countries where patients infected with the new
influenza A (H1N1) virus are being treated.

Whenever possible, clinical data and serial samples for virological
monitoring should be collected prospectively in the context of a clinical
protocol, starting before treatment, to allow assessment of the effects of
treatment regimens. Retrospective reporting of clinical and laboratory
data from patients who had recently been infected may also be helpful.
Reporting clinical findings and treatment outcomes to WHO will greatly
facilitate the better understanding of the new disease and the development
of further management guidance.

Draft reporting forms are available at:
http://www.who.int/csr/resources/publications/swineflu/caseformadapted20090508.pdf

Infection control

Appropriate infection control measures (Standard plus Droplet Precautions)
should be adhered to at all times. Whenever performing high-risk
aerosol-generating procedures (for example, bronchoscopy, or any procedure
involving aspiration of the respiratory tract) use a particulate
respirator (N95, FFP2 or equivalent), eye protection, gowns, gloves, and
carry out the procedure in an airborne precaution room that can be
naturally or mechanically ventilated, per WHO guidance.2

Diagnosis

Laboratory confirmation of the new influenza A (H1N1) virus, especially at
the beginning of a new community outbreak, or for unusual cases, has
important implications for case management, including those pertaining to
infection control procedures, consideration of antiviral treatment options
and avoiding the inappropriate use of antibiotics. Currently, the
confirmatory diagnostic tests can be done by specialized laboratories3 in
many countries. Reverse transcriptase polymerase chain reaction (RTPCR)
will provide the most timely and sensitive evidence of infection with the
new influenza A (H1N1) virus. Clinical diagnosis (based on the acute onset
of fever and cough) can be increasingly predictive of the new influenza A
(H1N1) virus infection as the prevalence of infections increase.

At present, there is no validated rapid bedside diagnostic test for the
new influenza A (H1N1) virus infection (including so-called
?point-of-care? diagnostic tests).
_______________
2
http://www.who.int/csr/resources/publications/infection_control/en/index.html

3 WHO can assist with laboratory testing. See
http://www.who.int/csr/disease/swineflu/guidance/laboratory/en/index.html

Commercially available rapid tests for seasonal influenza have uncertain
sensitivity and lack specificity for detection of the new influenza A
(H1N1) virus. If these tests are performed, both positive and negative
results should be interpreted with caution.

Samples for laboratory tests should be taken from the deep nasal passages
(nasal swab), nasopharynx (naso-pharyngeal swab), throat or, if available,
bronchial aspirate. Upper respiratory tract sampling using a combination
of a nasal or nasopharyngeal and a throat swab is advised and may
facilitate virus detection. It is not yet known which clinical specimen
gives the best diagnostic yield for this specific infection. Specimen
collection should be done with appropriate precautions since this may
expose the collector to respiratory secretions from patients.

General treatment considerations

To date, most human cases of new influenza A (H1N1) virus infection have
had uncomplicated illness of limited duration. Hospitalization or
antiviral therapy is therefore not likely to be required for most
patients. Supportive care includes antipyretics, such as paracetamol or
acetaminophen for fever or pain, and fluid rehydration and can be provided
as needed. Salicylates (such as aspirin and aspirin-containing products)
should not be used in children and young adults (aged <18 years) because
of the risk of Reye?s syndrome.

The specific risk factors that predict increased risk of progressive
disease are incompletely understood. Clinicians and caregivers should
watch for signs of possible clinical deterioration (for example,
difficulty in breathing, chest pain, coughing up coloured sputum, altered
level of consciousness and confusion) and refer such patients immediately
to hospital. Clinicians should also take into account any underlying
comorbidities (such as immune-compromising conditions, pre-existing
chronic lung or cardiovascular disease, diabetes).

Pregnant women are known to be at increased risk of complications from
seasonal, avian H5N1 and previous pandemic influenza infection. Several
hospitalizations including fatal outcomes have been reported in pregnant
women infected with the new H1N1 virus. Consequently, pregnant women with
suspected or confirmed new influenza A (H1N1) infections warrant closer
observation and, if in accordance with national policies, treatment with
antivirals (see below).

Oxygen therapy

At presentation or triage and routinely during subsequent care in
hospitalized patients, oxygen saturation should be monitored by pulse
oximetry whenever possible. Supplemental oxygen should be provided to
correct hypoxaemia. The WHO recommendations for pneumonia advise oxygen
therapy to maintain oxygen saturations above 90%; however, this threshold
may be increased to 92?95% in some clinical situations, for example during
pregnancy. Populations at altitude will require different thresholds for
diagnosing hypoxaemia but will also have increased susceptibility to
severe hypoxaemia in the presence of pneumonia or ARDS.

Patients with severe hypoxaemia need high flow oxygen (e.g. 10 litres per
minute) delivered by face mask. Some patients who experience difficulties
with compliance (such as children) may require the close involvement of
nursing staff or family members. Where piped oxygen is not available, a
supply of large cylinders will be needed. WHO has included oxygen in its
List of Essential Medicines since 1979, but oxygen is still not widely
available in some countries. If medical oxygen is not available,
industrial oxygen can be used.4 Oxygen treatment of newborn infants should
follow guidelines5.

Antibiotic treatment

Antibiotic chemoprophylaxis should not be used. When pneumonia is present,
treatment with antibiotics should generally follow recommendations from
published evidencebased guidelines for community-acquired pneumonia6.
However, seasonal influenza and past influenza pandemics have been
associated with an increased risk of secondary Staphylococcus aureus
infections, which may be severe, rapidly progressive, necrotizing, and, in
some areas, caused by methicillin-resistant strains. The results of
microbiological studies, wherever possible, should be used to guide
antibiotic usage for suspected bacterial coinfection in patients with the
new influenza A (H1N1) virus infection. Several patients in Mexico have
developed ventilator-associated pneumonia or hospital-acquired pneumonia
caused by typical nosocomial pathogens.

Antiviral therapy

The new influenza A (H1N1) viruses are currently susceptible to the
neuraminidase inhibitors (NAIs) oseltamivir and zanamivir but resistant to
amantadine or rimantadine (adamantane or M2 inhibitor drugs).7 Since the
H1N1 virus is new, clinical efficacy data on antiviral treatment are not
yet available. Based on its in vitro susceptibility patterns and clinical
experiences derived from seasonal and avian H5N1 influenza infection,
early administration of NAIs might reduce severity and duration of illness
caused by the new H1N1 virus infection, and might also contribute to
prevent progression to severe disease and death. Antiviral therapy may be
beneficial especially for the following groups:

? pregnant patients, in whom administration of antiviral medicines should
be carefully evaluated taking possible benefits and risks into
consideration;

? patients with progressing lower respiratory disease or pneumonia;

? patients with underlying medical conditions.

If used, antiviral treatment should ideally be started early, but it may
also be used at any stage of active disease when ongoing viral replication
is anticipated or documented. It is possible that the virus may replicate
for a prolonged period of time in some patients as a result of the lack of
pre-existing protective immunity.

There are important pharmacological differences to consider when choosing
NAIs for
___________________
4 http://whqlibdoc.who.int/hq/1993/WHO_ARI_93.28.pdf
5 http://whqlibdoc.who.int/publications/2003/9241546220.pdf
6 http://whqlibdoc.who.int/publications/2006/924159084X_eng.pdf (for
  pregnant women and newborns)
7 http://www.cdc.gov/mmwr/PDF/wk/mm5817.pdf

treatment. Oseltamivir is administered orally and gives higher systemic
level. , Zanamivir is delivered by oral inhalation with low systemic
absorption. Oseltamivir is the recommended treatment for lower respiratory
tract complications.

Rare neuropsychiatric symptoms such as confusion or abnormal behaviour
have occurred after beginning treatment for seasonal influenza with
oseltamivir, particularly in children and adolescents,8 but the
contribution of oseltamivir to these events is unknown. Inhaled zanamivir
has been temporally associated with bronchospasm and patients with
preexisting airway disease appear to be at increased risk for this severe
adverse reaction. Any suspected adverse events should be reported to
national regulatory authorities. Table 2 gives the recommended antiviral
treatment regimens by age and weight.

Corticosteroids

Corticosteroids should not be used routinely to treat patients with the
new influenza A (H1N1). Low doses of corticosteroids may be considered for
patients in septic shock who require vasopressors and have suspected
adrenal insufficiency. Prolonged use of or highdose corticosteroids can
result in serious adverse events in influenza virus-infected patients,
including opportunistic infection and possibly prolonged viral
replication.

Advance respiratory support

Treatment of ARDS associated with the new influenza A (H1N1) virus
infection should be based upon published evidence-based guidelines for
sepsis-associated ARDS. Lungprotective mechanical ventilation strategies
should be used.9
__________________
8 http://www.fda.gov/medwatch/safety/2008/safety08.htm#Tamiflu
9 For example,
http://www.survivingsepsis.org/system/files/images/2008_Guidelines_Final_.pdf


Table 1: Summary of clinical management of the new influenza A (H1N1)
virus infection

Modalities
Strategies

Antibiotics
In case of pneumonia, empiric treatment for community acquired
pneumonia (CAP) per published guidelines pending microbiologic results
(e.g. 2-3 days); tailored therapy thereafter if pathogen(s) identified.

Antiviral therapy
If treatment needed, oseltamivir or zanamivir. The new influenza A (H1N1)
virus is currently resistant to amantadine and rimantadine.

Corticosteroids
Moderate to high dose steroids are NOT recommended. They are of unproven
benefit and potentially harmful. Infection control Standard plus Droplet
Precautions. For aerosol-generating procedures use particular respirator
(N95, FFP2 or equivalent), eye protection, gowns, gloves, and an airborne
precaution room, that can be naturally or mechanically ventilated, per WHO
guidance10.

NSAIDS, antipyretics
Paracetamol or acetaminophen given orally or by suppository. Avoid
administration of salicylates (aspirin and aspirin containing products) in
children and young adults (< 18 years old) due to risk of Reye?s syndrome.

Oxygen therapy
Monitor oxygen saturation and maintain SaO2 over 90% (95% for pregnant
women) with nasal cannulae or face mask.

Table 2: Recommended antiviral treatment regimens

Oseltamivir

Oseltamivir is indicated for treatment of patients one year of age and
older. For adolescents (13 to 17 years of age) and adults the recommended
oral dose is 75 mg oseltamivir twice daily for 5 days. For infants older
than 1 year of age and for children 2 to 12 years of age recommended doses
are as follows:

15kg or less    30 mg orally twice a day for 5 days
15-23kg         45 mg orally twice a day for 5 days
24-40kg         60 mg orally twice a day for 5 days
>40kg           75 mg orally twice a day for 5 days

Zanamivir

Zanamivir is indicated for treatment of influenza in adults and children
(>5 years). The recommended dose for treatment of adults and children from
the age of 5 years is two inhalations (2 x 5mg) twice daily for 5 days.

10
http://www.who.int/csr/resources/publications/infection_control/en/index.html