• 15Oct

    Symptoms of the swine flu – how to diagnose it?

    Swine flu/influenza is an acute respiratory illness caused by infection with influenza group of viruses. The disease affects the respiratory tract. The mode of transmission of this disease is by coughing and sneezing.  Outbreaks of illness are of variable extent and severity occurs frequently. Such outbreaks result in significant morbidity (having a disease, being disabled or having poor health) in the general population and in increased mortality (death) rates among high-risk patients, mainly as a result of complications involving the lungs.

    Occasional cases of influenza are transmitted from pigs to humans. An outbreak of swine ‘flu’ began in 2009, initially in Mexico and then spread around the world. The causative strain is an H1N1 strain which has significant genetic variations from human strains of H1N1. This new sub type of influenza A (H1N1) virus has segments from four influenza viruses: North American Swine, North American Avian, Human Influenza and Eurasian Swine. Clinical features of infections with this strain are similar to influenza-A infection, although some cases have more prominent enteric (related to gastro-intestinal tract) features.

    Clinical features and symptoms of the swine flu

    The incubation period of the disease is 1 to 7 days. The incubation period is the duration between exposure to an infection and the appearance of  first symptoms. This disease remains communicable from one day before to seven days after the onset of symptoms or till the resolution of the illness.

    H1N1 virus can be transmitted from pigs to humans

    H1N1 virus can be transmitted from pigs to humans

    The systemic signs and symptoms are fever, cough, sore throat, headache, body ache, fatigue, diarrhea, vomiting and weakness. People with extremes of age or with pre-existing diseases are at higher risk of complications like sinusitis (inflammation of sinuses), otitis media (middle ear infection), pneumonia (lung infection), bronchiolitis (infection of respiratory passage), status asthamaticus (attack of asthma), myocarditis (inflammation of heart), pericarditis (inflammation of outer covering of heart), myositis (inflammation of muscles), rhabdomyolysis (breakdown of muscle proteins), encephalitis (brain inflammation), seizures (fits), secondary bacterial pneumonia with or without sepsis.

    Diagnosis of swine flu

    For confirmation of diagnosis, specimens like nasopharyngeal swab, throat swab, nasal swab and tracheal aspirate (for intubated patients) are obtained. Confirmation of influenza A(H1N1) swine origin infection is done through one or more of the following three tests: Real time RT PCR (Real time Reverse transcriptase polymerase chain reaction), isolation of the virus in culture or four-fold rise in virus specific neutralizing antibodies.

    Prevention of swine flu

    • It involves good infection control with hand hygiene to preclude dissemination through fomites (an inanimate object or substance, such as clothing, furniture, or soap that is capable of transmitting infectious organisms from one individual to another). The virus can survive in the environment for variable period of time (hours to days) Cleaning followed by disinfection should be done for contaminated surfaces and equipment. The virus is inactivated by many disinfecting agents like 70% ethanol, 5% benzalkonium chloride (Lysol) and 10% sodium hypochlorite.
    • Prevention of dissemination of infection by droplet infection (coughing, sneezing) through the use of high efficiency masks (N95 mask), isolation of patients and barrier nursing through use of ‘Personal Protective Equipment’ (PPE includes cap, three layered surgical mask, gloves and gown, protective eyewear) while treating the patients.
    • Vaccination – It is recommended that people from high-risk groups be vaccinated against H1N1 virus. This includes people with chronic diseases involving lungs, heart, kidney and liver. It also includes people with Parkinson’s disease, diabetes mellitus, pregnant women and people aged  over 65 years.


    • Antiviral drugs – Oseltamivir and Zanamivir are used for treatment. Oral Oseltamivir (75 mg 12-hourly) or inhaled Zanamivir (10 mg 12-hourly) given to adult patients for 5 days can reduce the severity of symptoms if started within 48 hours of onset of symptoms. For children the dosage depends on body weight. Antiviral drugs can also be used for prevention in high-risk individuals during the ‘flu season’. Resistance can emerge to all of these agents.
    • Supportive therapy – the seriously ill patients may require admission and supportive treatment in the form of IV fluids, oxygen inhalation, antibiotics for superadded bacterial infections and intravenous nutrition.
    • Aspirin is strictly contra-indicated in any influenza patient and especially in children due to risk of Reye’s syndrome (rash, vomiting, and liver damage) with high fatality rate.

    Anna L.

    It’s all about health!
    I have academic background in drugs related Chemical Technology, as well as extensive professional experience in pharma and medical companies. My main area of interest is everyday life medicine. The goal of my articles is to give people informative answers to the questions that bother them, to dispel doubts and some common misbeliefs and also to inspire everyone to keep healthy lifestyle.

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