SCI-ART LAB

Science, Art, Litt, Science based Art & Science Communication

There is a pandemic of swine flu now in this part of the world as well as other regions. People are dying. Even vaccines are not working properly and efficiently according to doctors and only 23% of the total vaccinated people are getting protection. Why is this so? Why is flu difficult to control? Here are a few answers to these questions.

Swine flu, also known as 2009 H1N1 type A influenza, is a human disease. People get the disease from other people, not from pigs. The disease originally was nicknamed swine flu because the virus that causes the disease originally jumped to humans from the live pigs in which it evolved. The virus is a "reassortant" - a mix of genes from swine, bird, and human flu viruses. The swine flu viruses that usually spread among pigs aren't the same as human flu viruses. 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 that has changed in ways that allow it to spread from person to person -- among people who haven't had any contact with pigs.

Many people have at least partial immunity to seasonal H1N1 viruses because they've been infected with or vaccinated against this flu virus. These viruses "drift" genetically, which is why the flu vaccine has to be tweaked from time to time. But the H1N1 swine flu is not the usual "drift variant" of H1N1. It came to humans from a different line of evolution. That means most people have no natural immunity to H1N1 swine flu. The normal seasonal flu shot does not protect against this new virus.

The virus spreads when you touch an infected surface or breathe cough and sneeze droplets in the air. If you are infected, you can be contagious for up to 10 days. The symptoms are the same as the seasonal flu -- cough, runny nose, sore throat, fever, chills, headache, body aches and fatigue. Some have diarrhea and vomiting. Young children, pregnant women, and older adults are more likely to develop complications. A rapid flue test can confirm the virus as the symptoms described above can be common to several other conditions. The accuracy of the test depends on the quality of the manufacturer’s test, the sample collection method, and how much virus a person is shedding at the time of testing.

People who are at particularly high risk of severe disease or bad outcomes if they get the flu: Pregnant women are six times more likely to have severe flu disease than women who are not pregnant, young children, especially those under 2 years of age, people with asthma,  COPD or other chronic lung conditions,  cardiovascular conditions (except high blood pressure),  liver problems, kidney problems,  blood disorders, including sickle cell disease,  neurologic disorders,  neuromuscular disorders, metabolic disorders, including diabetes,  immune suppression, including HIV infection and medications that suppress the immune system, such as cancer chemotherapy or anti-rejection drugs for transplants, residents of a nursing home or other chronic-care facility, elderly people are at high risk of severe flu disease -- if they get it. Relatively few swine flu cases have been seen in people over age 65. People in these groups should seek medical care as soon as they get flu symptoms. If people come into close contact with a person who has the flu -- especially if that person did not cover a cough or sneeze when they were within 6 feet -- they have been exposed. Exposure does not guarantee infection or illness, so there's still a good chance people won't get the flu. If you have any of the conditions that put you at increased risk of severe H1N1 swine flu -- pregnancy, asthma, lung disease, diabetes, heart disease, neurologic disease, immune suppression, or other chronic conditions -- it may be riskier for you to get the flu than for other people. That also goes for children under age 2 years, young people under age 19 taking daily aspirin therapy, and people over age 65.
One need not take medicines immediately when exposed if you don't belong to the high risk category . Experts advice you to wait till you develop any of the symptoms. If you face any of the symptoms, the next step is immediately go for a test. If the test confirms that you have swine flu virus, then only you need to go for the specific medicines. However, if you come under the high risk group you need to take the medicines as soon as you develop symptoms and you should not wait for the test results. The results sometimes don't give positive signs even if you have the flu. The drugs work best when taken within 48 hours of the first symptom, although even when taken much later they can prevent severe illness. Urgent medical attention is needed if you develop these symptoms: difficulty in breathing or shortness of breath, pain or pressure in the chest or abdomen, sudden dizziness, confusion, severe or persistent vomiting, flu-like symptoms that improve, but then come back with worsening fever or cough, you have flu symptoms.


Try not to spread the disease if you have the flu by following these things: When you cough or sneeze, cover your mouth and nose with a tissue or a cloth. Afterward, throw them in the trash and wash your hands. That will help prevent your flu from spreading. If you can do it comfortably, wear a surgical mask if you must be around others. Stay at home if you feel sick.

To protect from getting infections people should follow these precautions: Keep away from crowded places. Wear masks that are specifically designed for viruses when you go out. Wash your hands as frequently as possible with soap and clean water. Avoid touching your eyes, nose, or mouth. Germs spread this way.  Try to avoid close contact with sick people. Get vaccinated, although this may not give you full protection. Eat healthy food especially fruits and vegetables.

Tamiflu and Relenza can treat or prevent swine flu. But an annual flu shot is your best bet against this virus.  But vaccinations take time - at least three weeks - to protect you. Therefore, even if you are vaccinated, you might contact the flu before this period if you are exposed to the virus. The antiviral medications aren't a question of life or death for the vast majority of people. Most swine flu patients all over the world have made a full recovery without antiviral drugs. But that depends on how good your immune system works and how healthy you are to have one. A third antiviral drug, peramivir, can be used only in hospitalized patients with severe flu.

Many people who have died of H1N1 swine flu had bacterial co-infections, particularly pneumococcal infections. There's a vaccine against pneumococcal infections. It's routine for children and recommended for adults with underlying health conditions, smokers, or people over age 65. If your flu symptoms get worse after getting better, call your doctor immediately. You may need treatment with antibiotic medications. Most of the patients die because of the other complications developed during the infection like organ failures.

Tamiflu and Relenza can prevent swine flu, but the experts advice even at-risk people to try to avoid using the drugs indiscriminately. Not only is supply insufficient for preventive use, but preventive use appears to be a major factor in the few cases of drug-resistant H1N1 swine flu that have appeared.

There are vaccines against Swine flu. But there are a few problems with these vaccines.

Usually what happens is experts will decide which influenza strains that vaccine makers should target for next year’s flu season. It’s an annual medical guessing game of sorts, one backed by data but also plagued with uncertainty. And when the guesses don’t exactly match the reality, as happened this year, it can mean a dismal and deadly flu season. People will do their best. But the flu virus is very smart. It’s very, very frustrating and a very inexact science. Each year, the expert group will pore over surveillance information from around the globe, hear presentations from government researchers, and weigh recommendations from the World Health Organization. The specialists will cast their votes for the four specific flu strains — two each from the ‘‘A’’ and ‘‘B’’ types of the virus — that manufacturers should focus on in making the coming season’s vaccine. Then, they will wait and hope that they got their work right. Despite constant tracking and surveillance of the virus in labs across the world and the work of hundreds of specialists at universities, the WHO and agencies such as the Centers for Disease Control and Prevention (CDC), picking the correct flu strains still involves a measure of good fortune. Every few years, specialists miss the mark. The main problem is - the flu virus is highly unpredictable. It morphs very often, and a new variant emerges. This ‘‘drift,’’ as specialists call it, renders the season’s vaccine far less effective than initially expected. And people get sick despite taking the vaccines! Such viral drift has been a persistent problem over the years, although less devastating than the ‘‘antigenic shift’’ that occasionally occurs, creating an entirely new strain that leaves much of the population largely defenseless. That’s what led to the 2009 flu pandemic in some parts of the world.

Every February, the WHO identifies which strains in the Northern Hemisphere and other parts of the world where it can expect the severe cases that are most likely to wreak havoc the following flu season. The Governments take cues from WHO and take steps and gives guidelines to manufacturers. After that, drug makers develop formulations for each strain, and regulators ensure vaccines from numerous manufacturers are safe and similarly potent. ‘‘Standardization" is a critical job. Manufacturers also must produce and package millions of doses and distribute them to physicians’ offices and pharmacies in time for vaccinations to begin, ahead of the flu season in most of the developed countries. In developing countries, which mainly depend on overseas vaccination products, the activity happens mostly when there is an outbreak because of the severe regional cold waves. But then these vaccines produced in some other part of the world based on the specific needs of those regions need not work very efficiently in other parts of the world as the flu strains might differ from place to place.

But still it is a huge gamble medical people will take. Naturally the outcomes depend on the weather, 'smartness' and strains of the viruses prevalent and living conditions of the people. And the uncertainty continues.

Views: 406

Replies to This Discussion

405

A flu outbreak in India that has claimed over 1200 lives may not be identical to the 2009 North American strain A/California/07/2009, as recently reported in India. A comparative analysis conducted by scientists at the Massachusetts Institute of Technology (MIT) shows that the flu virus in India seems to have acquired mutations that could spread more readily and therefore requires deeper studies. As flu season in India winds down, the researchers call on officials to increase surveillance of this and future flu outbreaks and rethink vaccination strategies to account for potential new viruses.

The MIT analysis, which compared viral proteins important for virulence and transmissibility in the 2009 and 2014 flu epidemics, was conducted by professor Ram Sasisekharan, PhD, at the Koch Institute for Integrative Cancer Research, and his research scientist colleague Kannan Tharakaraman, PhD. It appears in the March 11 issue of the journal Cell Host & Microbe.
Influenza Surveillance: 2014–2015 H1N1 “Swine”-Derived Influenza Viruses from India
http://www.cell.com/cell-host-microbe/abstract/S1931-3128%2815%2900...

RSS

© 2017   Created by Dr. Krishna Kumari Challa.   Powered by

Badges  |  Report an Issue  |  Terms of Service