Transcript Emerging Influenza Viruses

‫سورة البقرة (‪)۳۲‬‬
Influenza is a serious respiratory illness which can be
debilitating and causes complications that lead to
hospitalization and death, especially in the elderly.
Influenza virus is a genus of the orthomyxoviridae family
of viruses. Influenza A virus causes influenza in bird and
some mammals.
There are three groups of influenza virus: influenza A, B,
and C. Influenza B and C viruses are associated with lowlevel sporadic disease and are never causes of pandemic
influenza. influenza A is responsible for most seasonal
influenza and all known pandemics.
On the surface of influenza virus reside two major
proteins; Haemagglutinin (HA) and Neuraminidase (NA).
Sixteen subtypes of HA (H1 to H16) and nine subtypes of
NA (N1 to N9) are recognized in aquatic birds.
Death mostly occurs as a consequence of primary viral
pneumonia or of secondary respiratory bacterial
infections, especially in patients with underlying
pulmonary or cardiopulmonary diseases.
The aim of this work is to study the current status of
emerging influenza viruses infections and their
clinical implications.
Avian flu is influenza infection in birds. The disease is of
concern to humans, who have no immunity against it. The
virus that causes this infection in birds can mutate to easily
infect humans.
There are many subtypes of avian influenza viruses,
but only some strains of four subtypes have been highly
pathogenic in humans. These are types H5N1, H7N3, H7N7
and H9N2.
Avian influenza transmission to humans appears to occur
predominantly as a result of direct contact with infected
poultry.
People at risk include those who are exposed to water and
surfaces contamination by bird droppings
There is no evidence that properly cooked poultry meat or
poultry products are a source of human infection by H5N1
influenza virus.
After exposure to infected poultry, the incubation
period generally appears to be 7 days or less, and in many
cases this period is 2 to 5 days.
Initial symptoms of H5N1 influenza may include fever
(typically a temperature of more than 38°C), headache,
malaise, myalgia, sore throat, cough, and rhinitis with lower
respiratory tract symptoms, shortness of breath and
radiological evidence of pneumonia.
Isolation
 Nose, Throat Swab
 Tissue culture
Two groups of antiviral agents are available for treatment
and prophylaxis of influenza
- Amantadine
- Rimantadine
- Oseltamivir phosphate
- Zanamivir
Oseltamivir is taken orally (75 mg twice daily), and
Zanamivir is taken via an inhalation apparatus (10 mg bid
for 5 days).
The WHO advises travelers to avoid contact with highrisk environments in affected countries.
The WHO continues to recommend that travelers to
affected areas avoid contact with live animal markets
and poultry farms.
Populations in affected countries are advised to avoid
contact with dead migratory birds or wild birds
showing signs of disease.
Avoid contact with infected poultry or with surfaces
and objects contaminated by their droppings .
Swine influenza is an infection by any one of several
types of swine influenza virus. Swine Influenza Virus is
any strain of the influenza family of viruses that is
endemic in pigs. As of 2009, the known SIV strain
include influenza C and the subtypes of influenza A
known as H1N1, H1N2, H3N1, H3N2 and H2N3.
The virus appears to have emerged first in Mexico in
late February 2009, this likely represents the first largescale transmission of this virus.
The main route of transmission is through direct contact
between infected and uninfected animals.
The direct transfer of the virus probably occurs either by
pigs touching noses, or through dried mucus.
Swine influenza (H1N1) is spread primarily via droplets and
to a lesser extent via hand-to-face transmission.
People with regular exposure to pigs are at increased risk of
swine flu infection.
 Chronic respiratory diseases (eg, asthma, COPD, bronchiectasis,
lung surgery)
 Obesity
 Pregnancy
 Smoking
 Diabetes mellitus
 Chronic cardiovascular diseases
 Renal diseases
 Immunosuppression (such as blood disorders, malignancy)
 Delay in presentation to hospital (and hence delay in initiating
antiviral therapy)
Symptoms include fever, cough, sore throat, body aches,
headache, chills and fatigue.








Dyspnea
Cyanosis
Bloody or colored sputum
Chest pain
Altered mental status
High fever that persists beyond 3 days
Hypotension
In children, danger signs include tachypnea or dyspnea,
drowsiness, and no desire to play
Diagnosis
1- CBC:  Relative lymphopenia
2- Serum enzymes:
-(AST/ALT) are often elevated
- Creatine phosphokinase  elevated
3- Radiographic:
-Initially (CXR)  shows no or minimal infiltrates.
-Later  bilateral patchy interstitial infiltrates
For patients with underlying medical conditions that
increase the risk of more severe disease, WHO
recommends treatment with either oseltamivir or
zanamivir. These patients should also receive treatment as
soon as possible after symptom onset, without waiting for
the results of laboratory tests.
Antiviral agents
Drugs indicated for treatment of H1N1 influenza A virus
include neuraminidase inhibitors (i.e. oseltamivir and
zanamivir).
Oseltamivir (Tamiflu)
Treatment for acute illness :75 mg capsule twice daily for
5 days .
Prophylaxis :75 mg capsule twice daily for 5 days .
Zanamivir
Treatment for acute illness : 10 mg inhaled orally twice
daily for 5 days .
Prophylaxis of household contact: 10 mg inhaled orally
twice daily for 10 days .
U.S. President Barack Obama
Being vaccinated against H1N1 flu
Available as monovalent, inactivated influenza A virus
vaccine (H1N1) for IM injection. Indicated for active
immunization against influenza caused by pandemic (H1N1)
2009 virus. Stimulates active immunity to influenza virus
infection by inducing production of specific antibodies.
Prevention of swine influenza has three components:
prevention in swine, prevention of transmission to
humans, and prevention of its spread among humans.
The use of vaccines on swine to prevent their infection is a
major method of limiting swine to human transmission.
Influenza spreads between humans when infected people
cough or sneeze, then other people breathe in the virus or
touch something with the virus on it and then touch their
own face (avoid touching your eyes, nose or mouth.
Germs spread this way). Swine flu cannot be spread by
pork products, since the virus is not transmitted through
food.
Chance of transmission is also reduced by disinfecting
household surfaces, which can be done effectively with
a diluted chlorine bleach solution.
Recommendations to prevent spread of the virus among
humans include using standard infection control against
influenza. This includes frequent washing of hands with
soap and water or with alcohol-based hand sanitizers,
especially after being out in public