Information About Swine Flu - Keep employees/associates informed

Please inform the employees/associates about this and take enough care to make sure that the virus doesn't spread. As Always "Prevention is Better than CURE"

Brief Information
About Swine Flu

Swine Flu or Swine Influenza, also called H1N1 Flu is an acute disease of respiratory system affecting pigs, caused by influenza virus (H1NI subtype). Now-a-days it is affecting humans too. World Health Organization (WHO) has declared Swine flu as pandemic, since it has already traveled more than 70 countries all over the world.
• First case in humans was reported in Mexico and the United States in March and April, 2009.
• In India, it was diagnosed for the first time in Hyderabad on May 16, 2009.
• On June 11 2009, WHO raised a pandemic alert level to Phase 6 globally (Phase 6 - indicates that a global pandemic is underway)
This illness is referred as "swine flu" because the genes of this virus strain were found to be similar to influenza virus occurring in pigs in North America. But, further studies have indicated that the virus is very different from the virus affecting North American pigs. It consists of two genes similar to that found in flu viruses affecting pigs in Europe and Asia, avian and human genes. Hence, scientists call it as "Quadruple Reassortant" virus.

Usually H1N1 does not infect but human infections can happen. It is communicable and can spread from person to person. Since, it is new to humans, there is little or no immunity against it and can cause severe and widespread impact.

Currently, there is no vaccine for protecting against this H1N1 virus. Therefore, it becomes important to follow "Prevention is better than cure". Most of the infected humans have recovered without any medication. According to Centers for Disease Control and Prevention (CDC), further more cases, more hospitalizations and more deaths are anticipated in the near future.


Mortality and Morbidity

Till date, the maximum number of confirmed and probable cases of H1N1 flu was in the age group between 5 and 24-years-old. For now, there are few cases and no deaths reported in the age of more than 64 years old, unlike seasonal flu.


Pathogenesis

Pigs carry the virus and spread it to young animals. However, there is no evidence that they remain in true long term carrier state. After inhalation, the virus gets deposited on the surface of the lower respiratory tract.

Incubation Period: The estimated incubation period in humans is unknown and could range from 1-7 days, and more likely 1-4 days. Patient may be contagious from one day before they develop symptoms to up to 7 days after they get sick. Younger children might potentially be contagious for longer periods.



Pathology
Uncomplicated infections might cause changes in the cranial ventral lung lobes. Bronchial and mediastinal lymph nodes get enlarged. The pathological changes that can be seen are:
• Sharp line of demarcation between normal and affected lung tissue can be identified with the affected tissue being purple and firm.
• Interlobular edema can be found in few cases.
• Airways get filled up with blood-tinged fibrinous exudates with peribronchial and perivascular cellular infiltration.
• Fibrinous pleuritis is seen in severe cases.
• Microscopically lesions show airways filled with exudate, with extensive alveolar atelectasis, interstitial pneumonia and emphysema.
• Research revealed that widespread interstitial pneumonia prevails up to 21 days after infection and causes hemorrhagic lymph nodes.


Transmission

Transmission of H1N1 is believed to be in a similar way to other influenza viruses.
• Large-particle respiratory droplet transmission: When an infected person coughs or sneezes near a susceptible person, airborne transmission occurs. It requires close contact between the infected and recipient persons because droplets do not remain suspended in the air and travel short distances not more than 6 feet.

Respiratory secretions and bodily fluids (diarrheal stool) of infected cases are potentially infectious. However, susceptibility of ocular, conjunctival, or gastrointestinal infection is not yet known.

• Contact with contaminated surface: Sometimes people may become infected by touching something with flu viruses on it and then touching their mouth or nose. Studies have shown that virus can survive on environmental surfaces for nearly 2-8 hours after being deposited on the surface and have the potential for infecting a person.


What works against the transmission?
• H1N1 virus can be destroyed by heat at 167-212°F [75-100°C].
• Detergents (Soap), chemical germicides including chlorine, hydrogen peroxide, iodophors (iodine-based antiseptics), and alcohols are also effective against human influenza viruses, if used in proper concentration for a sufficient length of time.

For example, wipes or gels with alcohol in them can be used to clean hands. The gels should be rubbed into hands until they are dry.





Myths and Facts

• People get infected from eating or preparing pork.

Fact- This virus does not spread by food or from eating pork or pork products, if properly handled and cooked.


• There is a risk of virus transmission from drinking water.

Fact - Research on susceptibility of this virus to conventional drinking water treatment processes is not yet completed. However, recent studies have demonstrated that highly pathogenic H5N1 avian influenza gets inactivated by free chlorine levels normally used in drinking water treatment. So, it is believed that other influenza viruses like novel H1N1 can also be inactivated by chlorination. No human case was documented as caused by exposure to influenza-contaminated drinking water, till date.


• It can spread through water in swimming pools, water parks, spas, interactive fountains, and other recreational water venues.

Fact – Till now, no case of influenza virus infection has been documented as caused by water exposure. Recreational water treated with disinfectant at CDC recommended levels (1–3 parts per million [ppm or mg/L] for pools and 2–5 ppm for spas) does not cause transmission of influenza viruses like avian influenza A (H5N1) virus. No research is completed on the susceptibility of novel H1N1 virus to chlorine and other disinfectants used in swimming pools, water parks, spas, interactive fountains etc. So, it is believed that novel H1N1 might be disinfected similarly.

• There is a risk of spread at recreational water venues outside of the water!
Fact - Recreational water venues are not different from other common group setting.


Sign and Symptoms

Symptoms occuring in infected human by H1N1 are like any other flu symptoms.
• Fever
• Chills
• Headache
• Upper respiratory tract symptoms - cough, sore throat, rhinorrhea, shortness of breath
• Myalgia
• Arthralgia
• Fatigue
• Vomiting
• Diarrhea
Certain groups including infants, elderly and persons with compromised immune systems may have a typical presentations.

Prevention of Spread of Swine Flu
The following points must be taken care of by the ill person to prevent its spread in the community.
• Keep distance from people when sneezing or coughing. Cover your nose and mouth with a single use tissue while coughing or sneezing, and dispose the tissue in trash after use.
• Wash your hands with soap and water or alcohol-based hand cleaners frequently after coughing or sneezing and when you take off face cover.
• Avoid touching your eyes, nose or mouth to prevent spreading of germs.
• Avoid close contact/touching/hand shake/kissing/hugging sick people.
• Avoid traveling when you are sick, for minimum 7 days after you fall sick. Stay home from work or school if you are sick.
• Separate airy space should be provided for sick people in home. Try to be away from the patient at least by 1 meter distance. Caretakers should be assigned for the sick person.

Emergency Warning Signs

Signs and symptoms that indicate the need for urgent medical attention include:
In children-
• Fast breathing or trouble breathing
• Bluish skin color
• Not drinking enough fluids
• Not waking up or not interacting
• Being so irritable that the child does not want to be held
• Flu-like symptoms improve but then return with fever and worse cough
• Fever with a rash
In adults-
• Difficulty breathing or shortness of breath
• Pain or pressure in the chest or abdomen
• Sudden dizziness
• Confusion
• Severe or persistent vomiting

Diagnosing H1N1

Clinicians should suspect novel influenza (H1N1) virus if an acute febrile respiratory illness or sepsis-like syndrome is presented. But, not all people with suspected novel influenza (H1N1) infection need to have the diagnosis confirmed, especially, if the person resides in an affected area even if the illness is mild.

Indications for investigation are- if the persons
• Require hospitalization or
• Are at high-risk for severe disease.
Tests: Upper respiratory specimens should be collected for testing H1N1 which includes nasopharyngeal swab or aspirate, nasal swab plus a throat swab or nasal wash, or tracheal aspirate.
A trained physician / microbiologist preferably should collect the sample before anti-viral treatment. The specimens should be kept in a refrigerator (not a freezer) at 4°C in viral transport media until testing. The samples should be transported within 24 hours for testing. If transportation cannot be done within time, it should be stored at -70°C. Paired blood samples should also be collected at an interval of 14 days for serological testing. Confirmation of influenza A (H1N1) swine origin infection is done by:
• Real time RT PCR or
• Isolation of the virus in culture or
• Four-fold rise in virus specific neutralizing antibodies.
The samples are to be tested in BSL-3 laboratory. At present, the following laboratories are the identified laboratories for this purpose:
1 National Institute of Communicable Diseases, 22, Sham Nath Marg, Delhi [Tel. Nos. Influenza Monitoring Cell: 011-23921401; Director: 011-23913148]
2 National Institute of Virology, 20-A, Dr. Ambedkar Road, Pune-411001 [Tel.No. 020-26124386]
A confirmed case of novel influenza A (H1N1) virus infection is defined as a person with an influenza-like illness with laboratory confirmed novel influenza A (H1N1) virus infection by real-time RT-PCR or viral culture.

A probable case of novel influenza A (H1N1) virus infection is defined as a person with influenza-like-illness who is positive for influenza A, but negative for human H1 and H3 by influenza RT_PCR.

A suspected case of novel influenza A (H1N1) virus infection is defined as a person who does not meet the confirmed or probable case definition, and is not novel H1N1 test negative, and is/has:
• a previously healthy person < 65 years hospitalized for influenza like illness OR
• influenza like illness and resides in a state without confirmed cases, but has traveled to a state or country where there are one or more confirmed or probable cases OR
• influenza like illness and has an epidemiologic link in the past 7 days to a confirmed case or probable case


Complications

Spectrum of illness is not yet known completely for this novel influenza H1N1A infection. Complications are expected to be similar to seasonal influenza such as:
• Exacerbation of underlying chronic medical conditions
• Upper respiratory tract disease - sinusitis, otitis media, croup
• Lower respiratory tract disease - pneumonia, bronchiolitis, status asthmaticus
• Cardiac - myocarditis, pericarditis
• Musculoskeletal - myositis, rhabdomyolysis
• Neurologic - acute and post-infectious encephalopathy, encephalitis, febrile seizures, status epilepticus
• Toxic shock syndrome
• Secondary bacterial pneumonia with or without sepsis.


High Risk Groups for Developing Complications

The age and risk groups who are at higher risk for seasonal influenza complications are believed to be at higher risk for swine- influenza complications due to the insufficient data available.

Groups at higher risk for seasonal influenza complications include:
• Children less than 5 years old;
• Persons aged 65 years or older; (Uncertain)
• Children and adolescents (less than 18 years) who are receiving long-term aspirin therapy and who might be at risk for experiencing Reye syndrome after influenza virus infection;
• Pregnant women;
• Adults and children with chronic pulmonary, cardiovascular, hepatic, hematological, neurologic, neuromuscular, or metabolic disorders;
• Adults and children with immunosuppression (including immunosuppression caused by medications or by HIV);
• Residents of nursing homes and other chronic-care facilities.


Vaccine for H1N1 Influenza A virus

There are no vaccines to contain the current swine influenza virus, causing swine flu in humans. It is not known whether human seasonal influenza vaccines can provide any protection. Influenza viruses transform very quickly. Hence, WHO needs access to maximum viruses to select the most appropriate candidate vaccine virus. Developing a vaccine against the currently circulating virus strain is important to provide maximum protection to people.