SWINE FLU (H1N1 Virus)
So what is Swine flu ?
Swine flu refers to a respiratory infection caused by Influenza A viruses that ordinarily cause illness in pigs. Like humans, pigs can get infected with an influenza virus. Humans can get infected with flu from pigs and this happens very rarely. And more uncommon feature is transmission of swine flu from human to another human.
Swine flu doesn't often infect people, and the rare human cases that have occurred in the past have mainly affected people who had direct contact with pigs. But the current swine flu outbreak is different. It's caused by a new swine flu virus(H1N1 Type A influenza virus) that has changed in ways genetically that allow it to spread from one person to another and it's happening among people who haven't had any contact with pigs.
This new swine flu strain is being called by a number of names, including: swine-origin influenza A, swine influenza A (H1N1), influenza A/California/H1N1, swine origin influenza virus, North American flu and influenza A (H1N1).
Symptoms of Swine Flu
Important clinical features of swine influenza include fever, and upper respiratory symptoms such as cough and sore throat. Head ache, body ache, fatigue diarrhea and vomiting have also been observed.
There is insufficient information to date about clinical complications of this variant of swine origin influenza A (H1N1) virus infection. Clinicians should expect complications to be similar to seasonal influenza: sinusitis, otitis media, croup, pneumonia, bronchiolitis, status asthamaticus, myocarditis, pericarditis, myositis, rhabdomyolysis, encephalitis, seizures, toxic shock syndrome and secondary bacterial pneumonia with or without sepsis. Individuals at extremes of age and with preexisting medical conditions are at higher risk of complications.
Investigations
Includes haematological, biochemical, radiological and microbiological tests as necessary.
Confirmation of influenza A(H1N1) swine origin infection is through:
¯ Real time (RT) PCR or
¯ Isolation of the virus in culture or
¯ Four-fold rise in virus specific neutralizing antibodies.
Treatment
The guiding principles are:
¯ Early implementation of infection control precautions to minimize nosocomical / household spread of disease
¯ Prompt treatment to prevent severe illness & death.
¯ Early identification and follow up of persons at risk.
Oseltamivir Medication
— Oseltamivir is the recommended drug both for prophylaxis and treatment.
— Dose for treatment is as follows:
— By Weight:
- <15kg 30 mg BD for 5 days
- 15-23kg 45 mg BD for 5 days
- 24-<40kg 60 mg BD for 5 days
- >40kg 75 mg BD for 5 days
As on 30.04.09, 148 laboratory confirmed human cases of Swine influenza A (H1N1) has been reported from nine countries with 8 deaths. ( Mexico [26 cases, 7 deaths], USA [91 cases, one death], Canada (13), Austria(1), Germany (3), Israel(2), New Zealand (3), Spain(4), and United Kingdom (5). Over 1300 suspected cases have been reported with about 100 deaths. The outbreak started in Mexico on 18th March, 2009 and spread to USA and Canada and then to other countries.
WHO has heightened the pandemic level to Phase 5 implying widespread human infection.
