The Return of Swine Flu – A Death in the U.S. and Uncertainty

Sadly, the U.S. reported its first death in a 23 month old Mexican toddler visiting in Texas.

Cases have developed in countries on at least five continents over a brief time period. The first death in the U.S. among 64 cases, which is also the first death globally outside of Mexico among 100 or more cases, is difficult to put into perspective with any confidence – especially since the baby came from Mexico. The death of a baby in the U.S. is tragic, but each year we see 36,000 deaths from influenza in our country. Influenza is always serious – even without an exotic strain from another country. We cannot at this time predict the mortality of the Swine flu outbreak, but only put in a range of 0.1% of cases to something higher such as 0.5% (seen in the 1957 “Asian” flu and 1968 “Hong Kong” flu pandemics). A 1% mortality may be worst case scenario and seems unlikely.

If more deaths are occurring in Mexico than the rest of the world, why would this happen? In both the U.S. and Mexico the same virus is attacking the same age cohort – young adults. Then any big differences would be ascribed to differences in patients. Is it possible that patients in Mexico have co-infection with a second virus? Do they have high rates of secondary bacterial pneumonia with Staphylococcus aureus or Pneumococcus? Is the particulate air pollution in Mexico City damaging airways and lungs causing more disease? Do patients have an unusually robust immune response to the virus – the so-called cytokine storm? We do not know the answers to any of these questions, but the key point is this: CDC in concert with health authorities in Mexico should perform sophisticated viral and bacterial studies, and pathology analyses on patients with severe disease and on patients who have died. Our understanding of how to manage this viral infection will be enhanced with such information.

As we prepare ourselves in the U.S. for more illnesses and more deaths from the new Swine flu, it is the uncertainty that is especially challenging. Knowing the cause of severe illnesses and deaths and the true mortality will be of critical importance.

The Return of Swine Flu: Mexico vs. U.S.

Those who boldly predict the outcome of influenza do so at their own peril.

The 2009 Swine Flu outbreak in the U.S. and Mexico is different than previous outbreaks. The key issue today is why deaths have been reported in Mexico and not elsewhere. The same virus is attacking the same age group - healthy young adults - in the affected countries. So, the difference in outcome must be differences among the patients. This is likely due to one of three things: in Mexico, the patients have more secondary bacterial pneumonia (e.g. with Staph or Pneumococcus), or co-infected with flu virus and another virus, or there is more damage to the lungs given the high level of pollution in Mexico City.

Since the cases in the U.S. are mild, it cannot be the rapid access to ICUs here that is saving lives - as some have speculated. Furthermore, the antivirals are weak therapeutic agents, which disproves that our access to therapy is saving patients with the disease.

The good news is that we have two antivirals that are effective against the circulating strain of Swine Flu. The key point, however, is that each offers excellent protection as a prophylactic agent- from recent studies of the antivirals about 70% of exposed but not ill people can be spared infection. Yet both drugs are marginal as therapeutic agents, and neither has been rigorously tested in life-threatening cases of flu. That is the reason to seek a safe and effective vaccine.

There are important lessons from prior influenza and Severe Acute Respiratory Syndrome (SARS) pandemics:

* Accurate and early reporting of all cases globally is essential for control. The delays in reporting the initial cases of SARS in China contributed to its early dissemination.

* Infection Control in hospitals must be assiduous to avoid spread to health care workers and other patients. This was noted early in Canada with the SARS pandemic, and rapid interventions led to its control there. Specifically, handwashing and prudent use of masks are helpful and effective. If the new Swine Flu strain shows occasional ability to be airborne within microscopic droplets, the use of negative air pressure rooms - if available to keep the air currents going only in the direction of the patient's room- may help.

* Lastly, the need for psychological support of health care workers was not fully appreciated early in the SARS outbreaks. These dedicated men and women are overepresented by young adults- susceptible to Swine Flu. Careful attention to their needs and support for their families would be essential.

In 1976, when my colleagues and I reported two patients in Virginia with Swine Flu, it added some concern that the original cluster at Fort Dix had spread beyond New Jersey. President Ford received impassioned advice from health policy experts at that time and strongly advocated a national vaccine program. Subsequently, there were two unexpected outcomes: The Swine Flu epidemic never materialized, and the vaccine unexpectedly caused a 7-fold increase in a neurological side effect leading to weakness and paralysis, the Guillian Barre Syndrome. A shakeup at CDC followed, and for years the public's willingness to accept vaccines was diminished.

It is unclear if Swine flu will act more like the devastating avian flu pandemic of 1918-19 or the fizzled Swine flu outbreak of 1976. However, the latest "influence" to visit itself upon the citizens of the world reminds us that epidemics are part of the natural interaction of people and microbes throughout civilization. Yet each time we react as though we have discovered something new. The only really new things are our surprise and consistent inability to recall all of the lessons from prior visitations.

KEEP THOSE HANDS TO YOURSELF TO REDUCE SPREAD OF DISEASE

The handshake is deeply ingrained in our culture. Other than the kiss, it’s the way we are taught to say hello, goodbye, or to “seal a deal.”

It is thought to be an ancient custom whereby strangers encountering each other could show that no weapon was being held, but the handshake may have outlived its usefulness. In fact, the Japanese and Europeans could have a better idea. Rather than shaking hands when they meet each other, the Japanese clasp their own hands and bow, and the Europeans peck each other on both cheeks.

No hands meet. And that may be a very good thing to think about when it comes to preventing the spread of infectious diseases, like the common cold, the norovirus (the flu), and the deadly MRSA bacteria.

It turns out that shaking hands is among the best ways to spread germs. According to a recent study by the London School of Hygiene, hands are a critical link in the chain of illness as they transmit infections from surfaces to people and person to person.

Actually, it turns out this warning is really nothing new. As far back as 1919, The New York Times reported on a Montclair, New Jersey health officer, John Gaub, who issued a warning about the dangers of “indiscriminate hand shaking” in his community.

Of course, you can always wash your hands after shaking with someone, which is the most effective way to stop the spread of viruses. A study of Detroit school children found that those who regularly washed their hands had 24 percent fewer sick days due to respiratory illness and 51 percent fewer due to stomach illness.

But unless handwashing is done perfectly, some germs may linger.

While most people think that viruses, particularly the flu, are spread through the air - the truth is they are most often passed from one person to another when the sick person rubs his nose and touches something like the handle you are about to use to open the bathroom door, or the keyboard you touch or the telephone you pick up. If you then touch your own eye or nose or mouth, you may initiate an infection from your newly contaminated hands.

While the flu season is still raging – and cities like Boston feel its worst effects with the tragic death of 12-year-old boy from the flu -- the potential for infection spreading continues to loom, it just makes sense to reinforce the simple and obvious ways that we can avoid getting sick

Wash your hands frequently. And stop shaking hands.
It’s not rude. It is a lesson in good health.