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H1N1 Notes: Some Cases Without Fever; Postexposure Prophylaxis in Pregnancy
Pregnant women "in close contact" with those who have confirmed, probable, or suspected swine-origin influenza A (H1N1) infection should receive a 10-day course of zanamivir or oseltamivir, according to an MMWR Dispatch report on three pregnant women with H1N1, one of whom died.
The report also recommends that pregnant women with confirmed, probable, or suspected disease should receive antivirals for 5 days. Oseltamivir is "normally not recommended for use during pregnancy," according to its label, but the CDC says the drug is the preferred treatment for pregnant women during this outbreak. Oseltamivir should be started within 48 hours of symptom onset.
In other flu-related news, the New York Times reports an "odd feature" of the H1N1 virus — about one third of infected patients at two Mexican hospitals did not have fever when screened. Given that many experts consider fever "the most important sign of the disease," the Times says, its absence "could increase the difficulty of controlling the epidemic."

H1N1 Flu's Course Showing 'Encouraging Signs'

Swine-origin influenza A (H1N1) shows "a lot of encouraging signs" of taking a more benign course, according to CDC acting director Richard Besser.
For one, the virus is not showing the virulence markers associated with more serious disease, which Nancy Cox of the agency's influenza division calls "very good news." Secondly, H1N1's typical clinical course is only about as severe as garden-variety seasonal flu, says Dr. Besser.
The CDC officials say they will keep an eye on the virus's behavior in the Southern Hemisphere, where the flu season is about to begin. Changes in its behavior there could portend trouble when flu season returns to the Northern Hemisphere toward the end of the year.
As of Monday, H1N1 flu was confirmed in 286 patients in 36 states, according to Dr. Besser. There were more than 700 "probable" cases in 44 states.

Flu Cases — But Not Severity — Increase with Wider Testing; Journals Weigh In

The count of H1N1 cases in the U.S. is approaching 2000, and more are expected as test kits reach the states, but cases generally seem "self-limited and uncomplicated," MMWR reports.
In response to the epidemic, medical journals have begun to weigh in with data, advice, and resources.
American Family Physician offers an online article on the telephone triage of patients with suspected H1N1 disease.
BMJ thinks that the world is "not necessarily" well prepared for all this — especially the developing world, which is "unlikely to receive an effective vaccine early (if at all), once it is produced in large amounts."

Schools Should Reopen, CDC Says, as H1N1 Flu Threat Apparently Eases

Students with influenza symptoms should stay at home for a week, rather than having schools close, the CDC recommends in the face of more information on the severity of swine-origin influenza A (H1N1).
"Students, faculty and staff who appear to have an influenza-like illness ... should be isolated promptly in a room separate from other students and sent home," according to an announcement from the CDC and Health and Human Services. "It's important to note that schools that were closed based on previous interim CDC guidance related to this outbreak may reopen," it advises.
CDC officials say that H1N1 flu continues to act like seasonal flu, and in Mexico, wider surveillance paints a less alarming picture than previously feared.

A New Virus Emerges

Novel influenza A (H1N1) is a new flu virus of swine origin that was first detected in April, 2009. The virus is infecting people and is spreading from person-to-person, and has sparked a growing outbreak of illness in the United States with an increasing number of cases being reported internationally as well.
CDC anticipates that there will be more cases, more hospitalizations and more deaths associated with this new virus in the coming days and weeks because the population has little to no immunity against it. Novel influenza A (H1N1) activity is now being detected in two of CDC’s routine influenza surveillance systems as reported in the May 8, 2009 FluView. FluView is a weekly report that tracks U.S. influenza activity through multiple systems across five categories.
The May 8 FluView found that the number of people visiting their doctors with influenza-like-illness is higher than expected in the United States for this time of year. Second, laboratory data shows that regular seasonal influenza A (H1N1), (H3N2) and influenza B viruses are still circulating in the United States, but novel influenza A (H1N1) and “unsubtypable”* viruses now account for a significant number of the viruses detected in the United States.
It’s thought that novel influenza A (H1N1) flu spreads in the same way that regular seasonal influenza viruses spread; mainly through the coughs and sneezes of people who are sick with the virus.
CDC continues to take aggressive action to respond to the outbreak. CDC’s response goals are to reduce the spread and severity of illness, and to provide information to help health care providers, public health officials and the public address the challenges posed by this new public health threat.

H1N1(Swine flu)
Swine flu is a type of virus. It's named for a virus that pigs can get. People do not normally get swine flu, but human infections can and do happen. The virus is contagious and can spread from human to human. Symptoms of swine flu in people are similar to the symptoms of regular human flu and include fever, cough, sore throat, body aches, headache, chills and fatigue.
There are antiviral medicines you can take to prevent or treat swine flu. There is no vaccine available right now to protect against swine flu. You can help prevent the spread of germs that cause respiratory illnesses like influenza by

Covering your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
Washing your hands often with soap and water, especially after you cough or sneeze. You can also use alcohol-based hand cleaners.
Avoiding touching your eyes, nose or mouth. Germs spread this way.
Trying to avoid close contact with sick people.
Staying home from work or school if you are sick.

WHO Promises H1N1 Swine Flu Vaccine for All

By Daniel J. DeNoon
WebMD Health News
Reviewed By Brunilda Nazario, MD
May 6, 2009 -- If there's an H1N1 swine flu pandemic, vaccine makers should be able to churn out "at least" 1 billion to 2 billion doses of H1N1 swine flu vaccine, the World Health Organization (WHO) estimates.
The WHO hasn't yet declared an official pandemic. But given the growing number of cases worldwide -- as of Wednesday, 1,658 confirmed cases in 23 nations -- acting CDC Director Richard Besser, MD, says it would be surprising if an official pandemic was not eventually announced.
If that happens, world vaccine production would lag only four to six months behind, says Marie-Paule Kieny, PhD, the World Health Organization director of the Initiative for Vaccine Research.
"The current world capacity to make seasonal influenza vaccine is around 900 million doses per year," Kieny said today at a news conference. "This would translate to 1 billion to 2 billion doses of H1N1 vaccine if there should be a pandemic."
The decision whether to ask vaccine manufacturers to go full speed ahead with making an H1N1 swine flu vaccine may be made on Thursday at a WHO advisory committee meeting. The committee is charged with advising the WHO secretary-general to make a formal request to manufacturers.
Besser said the CDC has not yet decided whether to ask manufacturers for a swine flu vaccine, although early vaccine preparations are under way.
Many obstacles to a vaccine remain:

It's not yet known how well the H1N1 virus will grow in eggs.
There's no way to know for sure that vaccines against the current H1N1 virus strain will match the virus spreading six months from now.
It's not clear how many vaccine doses will be needed for immunity. If people already have some immunity from immunization or prior infection with seasonal H1N1 flu bugs, only one dose may be needed. If not, two doses may be required.
It's not known how big a dose of vaccine will be needed. If big doses are needed, there will be fewer doses to go around.
Any new vaccine will have to clear at least preliminary safety tests.

Next week, Kieny said, the WHO will meet with vaccine makers to discuss how to make sure poorer nations have access to H1N1 swine flu vaccine.
"We are appealing to corporate responsibility and working together toward equitable access," she said. "The manufacturers we have discussed this with have been very forthcoming, and we hope in the coming weeks to announce some agreement has been signed."
Meanwhile, Besser urged Americans to stay on the alert.
"This remains a dynamic situation," he said at today's news conference. "We remain concerned. We see continued spread around the country."
As state health departments receive test kits from CDC, they are working through their backlog of suspected cases. The result is that case numbers have surged a bit. But Besser noted that new cases of H1N1 swine flu continue to occur, and that more severe cases and deaths can be expected.
As of today, there were 1,487 probable and confirmed cases in 44 states. The ages of the patients in these cases range from 3 months to 81 years, but the median age is 16. It's still not clear why older children and young adults are more likely to get the new flu.

Influenza A(Swine flu) H1N1 update

As of 16:00 GMT, 3 May 2009, 18 countries have officially reported 900 cases of influenza A (H1N1) infection. Mexico has reported 506 confirmed human cases of infection, including 19 deaths.

The higher number of cases from Mexico in the past 48 hours reflects ongoing testing of previously collected specimens. The United States Government has reported 226 laboratory confirmed human cases, including one death.
The following countries have reported laboratory confirmed cases with no deaths - Austria (1), Canada (85), China, Hong Kong Special Administrative Region (1), Costa Rica (1), Denmark (1), France (2), Germany (8), Ireland (1), Israel (3), Netherlands (1), New Zealand (4), Republic of Korea (1), Spain (40), Switzerland (1) and the United Kingdom (18).

WHO Status: Phase 5 (of 6 phases)
The World Health Organization (WHO) alert level remains at 5 (of 6 phases). Phase 6 requires the presence of community transmission in more than one WHO region. Health surveillance within all countries reporting the existence of Influenza A (H1N1) continues to be critical in order to identify if community transmission is occurring.
Further information will be available on the WHO website on a regular basis.
Number of confirmed and suspected cases in New Zealand
As at 3pm today

there are 5 confirmed cases of Influenza A(H1N1) - up one since yesterday
there are a further 12 probable cases - down one since yesterday
and 69 suspected cases - this is down 20 (from 89) yesterday afternoon.
In addition there are 335 people in isolation or quarantine and being treated with Tamiflu. This is down by 25 since yesterday afternoon. These are people who have developed symptoms of influenza within seven days of having been in the areas of concern or are close contacts of cases that have flu-like symptoms.

There is still no evidence of community transmission - that means that to date, all of the cases have recently returned from travelling in affected areas or been a close contact of a case.
The National Centre for Biosecurity and Infectious Diseases (ESR) is now able to report laboratory confirmed Influenza A (H1N1) and will continue to refer samples to the Melbourne WHO reference laboratory for re-confirmation as required under international reporting protocols.
These numbers will fluctuate as a result of more suspected cases being found, or suspected cases being ruled out.
Dr Fran McGrath, Deputy Director of Public Health

Paris, April 27 - 2009 - A virus circulating in Mexico and the USA and involving person to person transmission appears to cause in some cases severe disease in certain people infected by this virus. There is no evidence that this virus is transmitted by food.
It is not a classical human influenza virus called seasonal influenza, which causes every year millions of human cases of influenza worldwide but a virus which includes in its characteristics swine, avian and human virus components.
No current information in influenza like animal disease in Mexico or the USA could support a link between human cases and possible animal cases including swine. The virus has not been isolated in animals to date. Therefore, it is not justified to name this disease swine influenza. In the past, many human influenza epidemics with animal origin have been named using geographic name, eg Spanish influenza or Asiatic influenza, thus it would be logical to call this disease “North-American influenza”.
Urgent scientific research must be started in order to know the susceptibility of animals to this new virus, and if relevant to implement biosecurity measures including possible vaccination to protect susceptible animals. If this virus would be shown to cause disease in animals, virus circulation could worsen the regional and global situation for public health.
Currently, only findings related to the circulation of this virus in pigs in zones of countries having human cases would justify trade measures on the importation of pigs from these countries. The OIE will continue its alert function and will publish in relation with its Members, Reference Laboratories and Collaborating Centres all appropriate information in real time.
OIE and FAO underline the great value of the influenza veterinary laboratory network called OFFLU, in charge of the surveillance of the evolution of influenza viruses in animals. There is a strong need to reinforce this network whose members are urged to put immediately in the public domain any genetic sequence of influenza virus they obtain.
This influenza event underlines in all countries the crucial importance of maintaining worldwide veterinary services able to implement in animals early detection of relevant emerging pathogens with a potential public health impact. This capacity is fully linked with veterinary services good governance and their compliance with OIE international standards of quality.

CDC Updates on Swine-Origin Influenza A (H1N1)

Dispatches describe the swine flu outbreak in Mexico and in a New York City school.
On April 30, the CDC issued two dispatches describing the status of swine-origin influenza A (H1N1) case identification and disease spread in Mexico and in New York City.

Cases of influenza-like illness (ILI) were reported in several Mexican states in mid-April. Virus isolates were type A, but were not subtypable at first. Confirmation of typing as swine-origin influenza A by reverse-transcription polymerase chain reaction was accomplished on April 23, and a suspected case definition was developed: severe respiratory illness with fever, cough, and difficulty breathing. From the onset of the outbreak to the time of the update, authorities identified 1918 suspected cases, of which 286 were probable; 97 of these were confirmed. Eighty-four patients with suspected H1N1 infection died, including 7 with confirmed infection. Suspected cases were reported all over Mexico. Confirmed cases ranged in age from 1 to 59 years, and 62% were female. In addition to respiratory symptoms, seven of 16 patients with complete in-hospital follow-up reported either vomiting or diarrhea. Attempts to curtail the outbreak have included education, distributing masks and hand sanitizers, closing schools and businesses, and discouraging large gatherings.

On April 24, the CDC reported 8 confirmed cases of swine-origin influenza A in Texas and California; as of this writing, half of the confirmed U.S. cases involve students and staff at a single New York high school. Initially, 222 students at the school were identified as having seen the nurse with acute illness. Alerted by the Mexican cases, the New York Department of Health collected nasopharyngeal swabs from 9 newly symptomatic individuals and decided to close the school. Authorities attempted to reach the remaining 213 individuals who reported illness between April 26 and April 28. Overall, authorities confirmed 44 cases, all but one of whom were students; the median age was 15 years, and 70% were female. None of the patients had traveled to Texas, California, or Mexico. Unlike the Mexican cases, the New York patients reported symptoms similar to those seen with seasonal flu, but gastrointestinal complaints (including nausea, vomiting, and diarrhea) occurred in about half the patients. An online survey of other students at the school revealed that several had traveled to Mexico in the weeks before the outbreak; enhanced surveillance of these and other students is ongoing.

Treatment guidelines include oseltamivir or zanamivir (neuraminidase inhibitors) for hospitalized patients with suspected, probable, or confirmed H1N1 infection or severe respiratory illness and underlying immunodeficiency or other conditions that increase risk for severe infection. These same agents are being recommended as prophylaxis for healthcare workers who provided care to patients in the New York cluster and who did not use proper personal protective measures for high-risk close household contacts of probable, suspected, or confirmed cases.

Comment: It is still too early to predict the magnitude of the swine flu outbreak. It has reached pandemic proportions, not as measured by the total number of sick patients, but by number of countries it has affected in a very short time. WHO authorities noted in a May 2 press briefing that although the virus is present in more than a dozen countries, there is no sign of sustained community transmission outside of North America, and Mexico’s health minister said on May 1 that the rate of infection does not appear to be as rapid as originally feared. Nonetheless, the emergence of a virus similar to the one that caused the 1918 pandemic has sounded a clear alarm about the eventuality of a major influenza pandemic and tested the preparedness of public health agencies throughout the world.
— Stephen G. Baum, MD