EMERGING INFLUENZA VIRUSES INTRODUCTION Influenza is a serious

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EMERGING INFLUENZA VIRUSES

EMERGING INFLUENZA VIRUSES

INTRODUCTION

INTRODUCTION

Influenza is a serious respiratory illness which can be debilitating and causes complications that

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 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

On the surface of influenza virus reside two major proteins; Haemagglutinin (HA) and Neuraminidase (NA). Sixteen subtypes of HA (H 1 to H 16) and nine subtypes of NA (N 1 to N 9) 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

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,

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. Subtypes: There are many subtypes of avian influenza viruses, but only some strains of four subtypes have been highly pathogenic in humans. These are types H 5 N 1, H 7 N 3, H 7 N 7 and H 9 N 2.

Transmission: Avian influenza transmission to humans appears to occur predominantly as a result of

Transmission: 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 H 5 N 1 influenza virus.

Incubation period: After exposure to infected poultry, the incubation period generally appears to be

Incubation period: 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. Symptoms: Initial symptoms of H 5 N 1 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

Isolation Nose, Throat Swab Tissue culture

Treatment Two groups of antiviral agents are available for treatment and prophylaxis of influenza

Treatment Two groups of antiviral agents are available for treatment and prophylaxis of influenza a) Viral M 2 Protein Inhibitors: - Amantadine - Rimantadine b) Selective Neuraminidase Inhibitors: - 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 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.

Infection Control Recommendations

Infection Control Recommendations

Infection control guidelines for H 5 N 1 avian influenza:

Infection control guidelines for H 5 N 1 avian influenza:

SWINE FLU

SWINE FLU

Swine influenza is an infection by any one of several types of swine influenza

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 H 1 N 1, H 1 N 2, H 3 N 1, H 3 N 2 and H 2 N 3. The virus appears to have emerged first in Mexico in late February 2009, this likely represents the first largescale transmission of this virus.

Transmission: Transmission between pigs: The main route of transmission is through direct contact between

Transmission: Transmission between pigs: 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. Transmission to humans: Swine influenza (H 1 N 1) 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.

Risk factors for severe infections § Chronic respiratory diseases (eg, asthma, COPD, bronchiectasis, lung

Risk factors for severe infections § 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)

Signs and symptoms: Symptoms include fever, cough, sore throat, body aches, headache, chills and

Signs and symptoms: Symptoms include fever, cough, sore throat, body aches, headache, chills and fatigue. Warning signs indicating more severe disease § § § § 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

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

Treatment: For patients with underlying medical conditions that increase the risk of more severe

Treatment: 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 H 1 N 1 influenza A

Antiviral agents Drugs indicated for treatment of H 1 N 1 influenza A virus include neuraminidase inhibitors (i. e. oseltamivir and zanamivir). Oseltamivir (Tamiflu) ØTreatment for acute illness : 75 mg capsule twice daily for 5 days. ØProphylaxis : 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 H 1 N 1 flu

U. S. President Barack Obama Being vaccinated against H 1 N 1 flu Available as monovalent, inactivated influenza A virus vaccine (H 1 N 1) for IM injection. Indicated for active immunization against influenza caused by pandemic (H 1 N 1) 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

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

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