DR. GIRISH BHASKAR
What started as an epidemic of swine flu in Mexico in March 2009 has now spread to 100 countries. The World Health Organization (WHO) has been alerting countries for the past eight years to get prepared for a major influenza outbreak. It seems to have finally arrived.
H1N1 virus moved from pigs and went on to infect humans, facilitated by crowded living conditions. From Mexico it spread to the United States, then to Europe and Asia. In the US, swine flu has so far killed 436 people and infected about 100,000 people. The situation will get worse as winter approaches parts of the world.
India has seen 21 deaths so far and this is causing panic among the populace. The good news is that the vast majority of the people who contract swine flu influenza are going to recover completely after going through a period of body aches, sore throat and fever.
If the Mexican experience is any guide, the H1N1 swine flu is sometimes lethal in children and young adults. This seems to be the pattern in India also. People born before 1957 appear to have some protection from the current pandemic. In the 1918 pandemic, it is estimated that close to 50 million people perished in different parts of the world.
In 2009, healthcare is very advanced compared to 1918. Tamiflu tablets if taken early may minimise the severity of the disease. But if Tamiflu is used indiscriminately, the virus will adapt and become resistant to the drug. Governments have stock piled millions of tablets to be used in a major outbreak.
The influenza virus sometimes settles down in the lungs and can cause severe respiratory distress requiring mechanical ventilatory support. Of the 2,155 cases of viral pneumonia reported from Mexico, 821 required hospitalisation and 100 died of respiratory failure in spite of mechanical ventilation. Not all viral pneumonia cases need ventilatory support.
Pharmaceutical companies are racing to bring a vaccine that could be effective against the swine flu virus. Pilot clinical studies are going on in America. The vaccine is expected to be available to the public in October of this year. One also needs protection against the regular flu virus which shows up every winter. It is unlikely there will be enough vaccine to vaccinate the entire world population. Pregnant women, children, young adults, healthcare professionals engaged in patient care, military personnel all should get priority.
Public need to remember that every year seasonal influenza causes 30,000 deaths in America especially the elderly with chronic lung disease, heart disease and kidney disease. Death generally happens only when there is severe involvement of both lungs by what is called acute lung injury or acute respiratory distress syndrome. With modern medical amenities, 42 percent of such cases can be saved.
Two classes of drugs are available to minimize the effects of flu on the body. They are Tamiflu (Oseltamivir) and Relenza (Zanamivir). Recently, Japanese scientists have successfully tested CS-8959 in a clinical trial. This drug may be released for public use in Japan next year. This is found to be safer and more efficacious than Tamiflu.
According to a British Medical Journal report, children under the age of 12 should not be given Tamiflu or Relenza. These drugs reduced the length of the flu infection by only one day. More importantly these drugs reduced the transmission of the virus only by eight percent.
The Mexican experience has also revealed the effectiveness of personal protective equipment, to prevent the infection of health care workers. Doctors and nurses taking care of critically ill patients should be given N 95 masks for their safety.
So many people are dying everyday from dengue fever, malaria, tuberculosis and various bacterial and viral infections. Yet, the media by heightening awareness about the disease has unwittingly engendered undue public anxiety.