“It’s a bit like Crichton’s The Andromeda Strain come to life,” says one person in disbelief. A pregnant cousin is pressing all the panic buttons she can see, greeting visitors with a daunting array of face masks, hand wipes and washes. “I’m in the high-risk category,” she says defiantly when quizzed about her reaction. “I’ve got a cough,” announces a seven-year-old to her mother. “At school, they said ‘don’t come if you have a cough or cold’.” Just try clearing your throat in a public place and chances are you’ll be glared out of the place.
Sounds familiar? Welcome to the world of swine flu. Words like ‘pandemic’, epidemic’, ‘H1N1’, ‘precautions’ have become part of everyday conversation, as people scramble for information. With people succumbing to the virus across the country, containing the spread is no longer feasible. The government has moved into mitigation mode, says Dr. Lalit Kant, Head, Division of Epidemiology & Communicable Diseases, Indian Council of Medical Research. “The case management guidelines for flu-like illness have also been modified to make them user-friendly and rationalising the need for testing, drug administration and hospitalisation,” he adds.
True, but people still panic. Just look at the media reports: thousands queue up at government hospitals for testing; centres run out of kits; contradictory reports about stockpiling of Tamiflu? The experts are not surprised at the reaction. For one, it’s not easy for a lay person to distinguish between ordinary flu and swine flu, says Dr. V. Ravi, Professor and Head, Department of Neurovriology, NIMHANS, Bangalore. The signs to watch out for, according to him, are fever above 38°C (100.4°F), running nose, sore throat and cough. “Around 30 per cent of laboratory-confirmed swine flu patients have also reported nausea, vomiting and diarrhoea. This is something not very common in ordinary flu,” he points out. Signs to look out for
But, he adds, it is neither possible nor necessary that every one should undergo tests for swine flu. As the revised guidelines issued by the Ministry of Health and Family Welfare lat week make clear, testing is required only if the patients show signs of breathlessness, chest pain, drowsiness, fall in blood pressure, sputum mixed with blood, bluish discolouration of nails; irritability among small children, refusal to accept feed; worsening of underlying chronic conditions. The others, Dr. Kant and Dr. Ravi stress, need to stay at home and avoid infecting others. Both doctors also agree that the policy of starting oseltamivir (better known as Tamiflu) treatment early is correct since “about 30 per cent of specimens tested are H1N1 positive.” The side-effects, both affirm, are relatively mild; Dr. Kant adds, “The benefits outweigh the potential drawbacks.”
With this outbreak coinciding with the festive season in India, we’re seeing cases of closure of malls, theatres, schools, colleges? Is this necessary or is it a knee-jerk reaction? There is no consensus on whether such interventions are useful, says Dr. Kant. The decision will depend on the local circumstances; there is no single uniform strategy. He also points out that the impact on economy and education will have to be weighed against the potential benefits of containing the spread of the virus. He reiterates the advice the media has also been disseminating: those with flu-like symptoms should impose restrictions on their movements, and stay at home for seven days after the onset of illness or at least 24 hours after symptoms have resolved, whichever is longer.
“There’s been so much scientific advance,” says one fretful mum. “Why can’t they find a vaccine or something?” Strangely her views find a distant echo in a recent article in the Virology Journal. William R. Gallaher of the Department of Microbiology, Immunology and Parasitology in Louisiana State University Health Sciences Center, comments that the 2009 H1N1 strain is “a novel virus quite unlike even the other H1N1 influenza viruses that have preceded it” and advocates quick development of “a new influenza vaccine ?prepared for worldwide administration.” Dr. Kant’s reaction is soothing: “There is no dearth of expertise, infrastructure or most importantly the enthusiasm. Work is proceeding in a public-private partnership mode and three indigenous manufacturers have imported the WHO seed strains.” He hopes that an Indian-made H1N1 vaccine will be available in 4-7 months.
Prepared for the future?
Now that is some time to wait, especially since winter’s coming and that is regular flu season. What happens if the virus mutates by then and develops into a different strain? Dr. Ravi agrees that this is a possibility since “influenza viruses are notorious for rapid mutations”, but Dr. Kant is not worried: “The current approach in the vaccine industry,” he points out, “is to set up a platform technology and refine the downstream production process. Creating a new vaccine for different strains won’t be a problem once the recommended seed strain is made available.” He compares it to inserting a new cassette while playing music; your player remains the same.
Given the outbreak of various pandemic situations in the last decade or so, first SARS, then bird flu and now swine flu, is there a link between them? “The obvious fact,” Dr. Kant says, “is that they all have a zoonotic link. SARS came from the civet cat, the avian flu from the migratory birds and now a strain that has links to bird, swine and human viruses.” Dr. Ravi is more expansive on why new viral diseases have emerged in this century and spread so rapidly: over-crowding of man, animals and birds in certain parts of the world leading to free exchange of viruses between the three species; rapid and easy access to international air travel has facilitated quick spread from one continent to the other; genetic mutation/recombination and re-assortment in the virus and, lastly, lack of herd immunity in the population to novel agents such as the H1N1 virus. Dr. Kant adds that given the proximity of contact between human and the animal world, this was inevitable.
Given that the doctors refer to previous influenza epidemics, one wonders if any lessons have been learnt from previous experiences and what this current crisis teaches us. Dr. Kant feels that, having learnt from the SARS and bird flu pandemics, India did manage to contain the initial spread of this disease “considering about five million people travel to India mostly from countries having high load of H1N1.” Dr. Ravi talks about learning “how to put systems in place in a laboratory that is flooded with specimens.” He makes a crucial point about “interaction with administrators and advising them on the correct steps to be taken and, most importantly, feeding evidence-based facts that are key to policy making.” At another level, he says the biggest challenge of this particular outbreak has been “the mad rush of samples for testing.” Given that each test costs about Rs. 5,000 (not including man hours and machine time) he calls it “an utter waste of national resources” to test each and every sample.
However with the inclusion of private labs to handle testing, the load on the government institutes will come down but Dr. Ravi sounds a cautionary note. He advocates a quick audit by laboratory experts to assess infrastructure, technical competence and laboratory practices before the lab is allowed to conduct the H1N1 test. “Bio-safety is top priority,” he says.
Testing process
First, proper sample collection at the designated hospital/ clinic. The staff who collect the throat swab and the nasal swab must be properly trained and follow personal protection measures.
Second, specimen processing in a bio-safety level 3 lab or bio-safety level 2 lab with level 3 practices takes approximately one hour.
Third, extracting the virus’ genetic material (RNA) takes about one-and-a-half hours.
Fourth, setting up and performing the Real Time Polymerase chain reaction (RT-RCR) takes two-and-a-half hours.
Last, analysis and reporting of results takes about 30 minutes.
Overall, it takes approximately six hours to complete testing after the sample is received in the laboratory. At a time, a batch of 10 samples can be processed. If we run 24/7services and overlap certain steps, a lab can test approximately 50-100 samples a day depending on the number of staff available.
Courtesy: Dr. V. Ravi
Other influenza virus subtypes and earlier outbreaks
Influenza type A viruses can infect people, birds, pigs, horses, and other animals, but wild birds are natural hosts. There are 16 known HA subtypes and nine known NA subtypes. Many different combinations of HA and NA proteins are possible. Only some influenza A subtypes (i.e., H1N1, H1N2, and H3N2) are currently in general circulation among people. Other subtypes are found most commonly in other animal species.
Influenza A H5: Nine potential subtypes of H5 are known. H5 infections, such as HPAI H5N1 viruses, currently circulating in Asia and Europe, have been documented among humans and sometimes cause severe illness or death.
Influenza A H7 : Nine potential subtypes of H7 are known. Infection in humans is rare but can occur among persons who have direct contact with infected birds. Symptoms may include conjunctivitis and/or upper respiratory symptoms.
Influenza A H9 : Nine potential subtypes of H9 are known but have rarely been reported to infect humans.
Influenza B viruses are usually found only in humans. Unlike influenza A viruses, these viruses are not classified according to subtype. Influenza B viruses can cause morbidity and mortality among humans, but in general are associated with less severe epidemics than influenza A viruses. Although influenza type B viruses can cause human epidemics, they have not caused pandemics.
Influenza type C viruses cause mild illness in humans and do not cause epidemics or pandemics.
Previous outbreaks
Influenza A virus strains caused three major global epidemics during the 20th century: the Spanish flu (H1N1) in 1918, Asian flu (H2N2) in 1957 and Hong Kong flu (H3N2) in 1968–69.
Other outbreaks include the Hongkong avian flu (H5N1) outbreak in 1997 and outbreaks of avian H5N1 infections with sporadic human spread in Vietnam, Thailand, Indonesia and Cambodia since 2003.
Source: Kilbourne ED.
Influenza pandemics of the 20th century. Emerging Infectious Diseases 2006;12(1): 9-14.Hsieh, Yu-Chia et al. Influenza pandemics: past present and future. Journal of the Formosan Medical Association 2006;105(1): 1–6.
Testing centres
Maharashtra: In Mumbai, Kasturba Hospital; Haffkine Institute; Sion Hospital; KEM Hospital; J.J. Hospital; Kokilaben Hospital; Nanavati Hospital; L.H. Hiranandani Hospital.
In Pune, Naidu Hospital; Sassoon Hospital; National Institute of Virology; Jehangir Hospital
Tamil Nadu: In Chennai, Lister Metropolis; Sri Ramachandra University; Bharat Scans, Royapettah; Hi-Tech Diagnostic Center, T.Nagar; Diagnostic Services, T.Nagar.
In Coimbatore: Immuno Ancilliary Clinic, Micro Labs, R.S.Puram.
In Nagercoil, Vivek Labs.
In Tiruchi, Dr. Rath’s Lab, Thillai Nagar.
