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Pandemic Flu Can Be Controlled Pending Availability of a Vaccine

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Prompt use of social-distancing measures, antiviral treatment and prophylaxis could control an outbreak of pandemic influenza in the United States, pending the availability of a vaccine, according to a recently-published study.

Three teams of researchers in the U.S, and England, in close collaboration with Government officials, studied various intervention combinations to guide national pandemic planning. The three research teams and an informatics group that participated are part of the Models of Infectious Disease Agent Study (MIDAS) Network, an effort funded by the National Institute of General Medical Sciences, or NIGMS.

"The federal government wanted three separate infectious-disease-modeling groups working on the same problem just to make sure the results were robust, since this data would be used to inform national pandemic planning," said the study’s co-author, Ira M. Longini Jr., Ph.D. "We got the highest level of input."

The researchers concentrated on assessing the effectiveness of a blend of antiviral and social-distancing interventions (like closing schools) in preventing a flu pandemic, since a vaccine was unavailable at the time. Other studies had shown that a vaccine would be very helpful in slowing a pandemic.

"The good news was that all three of the disease-modeling groups involved in the study found that an outbreak of pandemic flu similar to the pandemic of 1918 could be mitigated if these measures were implemented quickly," said M. Elizabeth Halloran, M.D., D.Sc., the study’s lead author.

To conduct the study, the researchers used three separate but similar computer models to calculate the spread of influenza within a population similar to that of Chicago, with approximately 8.6 million people. Members of this virtual community interacted the way people normally do: within households, schools and workplaces, and the community at large. All three models were set up to have attack-rate patterns similar to those of past U.S. flu pandemics.

Predicting the spread of an infectious disease such pandemic influenza requires much more than simply connecting dots on a map. Instead, Halloran and colleagues rely on a tool called stochastic modeling to take into account real-world unpredictability, as well as many factors about the disease and the affected population. In constructing these models, the researchers begin with assumptions about how people interact and how the virus spreads. They also introduce and evaluate the effectiveness of various intervention strategies.

These were the findings published in the online Early Edition of PNAS, a publication of the Proceedings of the National Academy of Sciences of the United States of America. M. Elizabeth Halloran, M.D., D.Sc., was the lead author, Ira M. Longini Jr., Ph.D., was the co-author. Both are researchers at Fred Hutchinson Cancer Research Center and professors of biostatistics at the University of Washington, and use mathematical and statistical methods to study the natural course of infectious diseases. Prior to publication, Longini presented the findings at the White House and at the Institute of Medicine.

Mathematical Model for Prescribing Antibiotics May Help Control Antibiotic Resistant Bacteria

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In the United States some 100,000 people die every year because they become infected in hospital with a strain of antibiotic-resistant bacteria. To combat this problem, a sophisticated mathematical model has been developed that changes the way that antibiotics are prescribed and administered.

"We have developed the mathematical model in order to identify the key factors that contribute to this problem and to estimate the effectiveness of different types of preventative measures in typical hospital settings," said Vanderbilt mathematician Glenn F. Webb, who described the results at a presentation at the annual meeting of the American Association for the Advancement of Science on Feb. 17, 2008 in Boston, Massachusetts.

The most effective way to combat this growing problem, said Mr. Webb, was to minimize the use of antibiotics. It was no secret, he continued, that antibiotics were overused in hospitals. How to optimize its administration was a difficult issue. But the excessive use of antibiotics, which may benefit individual patients, was creating a serious problem for the general patient community.

The model, developed by an inter-disciplinary team of researchers, showed that in a hospital where antibiotic treatments were begun 3 days after diagnosis and continued for 18 days, the number of cross-infections by resistant bacteria increased and decreased but never disappeared completely. When antibiotic treatments started the day of diagnosis and continued for 8 days, however, the cross-infection rate fell to nearly zero within 20 days.

. The mathematical analysis reveals that the "optimal strategy" for controlling hospital epidemics is to start antibiotic treatments as soon as possible and administer the drugs for the shortest possible time. Beginning treatment as early as possible is the most effective in knocking down the population of the non-resistant bacteria that is causing a patient’s initial illness and minimizing the length of treatment shortens the length of time when each patient acts as a source of infection. "Our results point out an urgent need for more research into the issue of the best timing for the administration of antibiotics and how to reduce its misuse and overuse," said Webb.

The model was developed by an interdisciplinary team of researchers. In addition to Webb, the contributors are Erika M.C. D’Agata at Harvard University’s Beth Israel Deaconess Medical Center, Pierre Magal and Damien Olivier at the Université du Havre in France and Shigui Ruan at the University of Miami, Coral Gables. It is described in the paper "Modeling antibiotic resistance in hospitals: The impact of minimizing treatment duration" published in the Journal of Theoretical Biology.

Source: Journal of Theoretical Biology, December, 2007.

Stress May Increase HPV and Cervical Cancer Risk

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Sress can reduce the immune system’s ability to resist HPV, a common sexually transmitted disease that may lead to cancer, according to a recent study published in the Annals of Behavioral Medicine. No such association is seen, however, between past major life events, such as divorce or job loss, and the body’s response to the infection.

"HPV infection alone is not sufficient to cause cervical cancer," explained Fox Chase Cancer Center’s Carolyn Y. Fang, Ph.D. "Most HPV infections in healthy women will disappear spontaneously over time. Only a small percentage will progress to become precancerous cervical lesions or cancer."

Women with precancerous cervical lesions were asked to complete a questionnaire detailing their stress in the past month, such as divorced, death of a close family member or job loss. "We were surprised to discover no significant association between the occurrence of major stressful life events and immune response to HPV16. This could be due to the amount of time that has passed since the event occurred and how individuals assess and cope with the event," said Fang.

"Our findings about subjective daily stress told a different story, however. Women with higher levels of perceived stress were more likely to have an impaired immune response to HPV16. That means women who report feeling more stressed could be at greater risk of events that had occurred, such as divorce, death of a close family member or loss of a job.

"We were surprised to discover no significant association between the occurrence of major stressful life events and immune response to HPV16. This could be due to the amount of time that has passed since the event occurred and how individuals assess and cope with the event," said Fang. "Our findings about subjective daily stress told a different story, however. Women with higher levels of perceived stress were more likely to have an impaired immune response to HPV16. That means women who report feeling more stressed could be at greater risk of developing cervical cancer because their immune system can’t fight off one of the most common viruses that causes it."

Fang’s study was funded by a grant from the National Cancer Institute.


Source: Annals of Behavioral Medicine (Vol. 17, No. 1)

Probiotics Reduces Respiratory Illness Rates in Athletes, Says Study

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A study in the British Journal of Sports Medicine finds that the rate and length of respiratory illness in distance runners is substantially cut by the probiotic Lactobacillus. The normal immune response to colds and flu can be suppressed by heavy exercise, which can leave some athletes vulnerable to them.

Twenty elite athletes took three freeze-dried capsules twice daily of the probiotic Lactobacillus fermentum or a placebo, during four months of winter training. Lactobacillus is a lactic acid bacteria that has been used in the treatment of gut infections. Treatments lasted four weeks each, interspersed by a month of nothing, so that by the end of the period all athletes had taken both the probiotic and placebo.

Respiratory tract infections were assessed, together with treadmill performance, immune response. While there was no difference in performance between between athletes taking the probiotic and placebo, athletes taking the probiotic had less that half the number of days of symptoms of the athletes taking the placebo. Specifically, respiratory symptoms while taking Lactobacillus lasted 30 days compared with 72 days for those taking the placebo. Levels of interferon gamma were doubled by the probiotic, an important element of the body’s immune response.

"Probiotics seem to increase systemic immunity, possibly by boosting the activity of T cells", say the researchers. "The potential of this probiotic to be used as a treatment to ward off illness merits further investigation", they say.

"An improvement in resistance to common illnesses constitutes an important benefit to elite athletes undertaking high level training in preparation for national and international competitions," they conclude.

Source: British Journal of Sports Medicine (First Br J Sports Med 2008; doi 10.1136/bjsm.2007.044628)

Industry Standards Needed for Children’s Flu Vaccine, Says Report

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Evaluating and establishing industry standards for flu vaccines for hospitalized children could help prevent additional hospitalizations and complications from influenza, according to a study published in a recent issue of Pediatrics.

A research team led by Danielle M. Zerr, MD, MPH, medical director of infection control at Seattle Children’s Hospital and associate professor of Pediatrics at the University of Washington School of Medicine (UWSOM), monitored the number of times children with influenza had been hospitalized, and summarized their findings in an article entitled "Hospital-Based Influenza Vaccination of Children: An Opportunity to Prevent Subsequent Hospitalization."

It was found that 23% of the children admitted to hospital with influenza had a previous hospitalization during the most recent flu season. This suggests that providing in-hospital vaccinations when the children were at highest risk for influenza could reduce the rates of childrens’ influenza during the flu season.

Approximately 14,000 children were hospitalized with influenza—and 170,000 were hospitalized with influenza or a respiratory illness—during a 5-year period (2001–2006) when discharge data provided by the Pediatric Health Information System (PHIS) database was analyzed. The data was checked to see how many children had a previous hospitalization during the most recent flu season.

Researchers found approximately 16% of those hospitalized with influenza and 23% of those hospitalized with influenza and another underlying condition had previous hospital admissions during the vaccination season.

"This information will help pediatricians recognize hospitalization as an important opportunity to vaccinate the highest-risk children, and may hopefully prompt the development of hospital-based flu vaccine programs," said Zerr.

The study looked at five years of hospital discharge data from the Pediatric Health Information System (PHIS) database from 2001 through 2006 to determine how many children hospitalized with influenza or respiratory illness had a previous hospitalization during the most recent flu-vaccine season. PHIS is an administrative database developed by the Child Health Corporation of America (CHCA), used by 42 free-standing pediatric hospitals. Subjects included newborns through age 18. A previous hospitalization during flu vaccination season was considered if it occurred in the two weeks to six months prior to the influenza admission and between September 1 and March 1. Approximately 14,000 cases of children hospitalized with influenza and 170,000 hospitalized with influenza or a respiratory illness were reviewed.

Source: Pediatrics, February, 2008

Hospitals Slow to Check Catheter-related Infections

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Twenty-five percent of Americans in hospital are given a urinary catheter, but a new study shows that hospitals are slow to prevent UTIs (urinary tract infections), which are the most common hospital acquired infections and represent 40% of such infections.

The study was published in the January issue of the journal Clinical Infectious Diseases by a team of safety experts from the University of Michigan Health System and the VA Ann Arbor Healthcare System, It shows that almost half of all hospitals do not have any way of knowing which patients currently have a catheter, and three quarters lack a system which tell them how long a patient has had a catheter, or whether one has been removed. Close to one third of hospitals do not monitor the UTI rates among their patients.

A method of reducing UTI rates and the time patients spend with catheters—
a simple daily reminder for doctors to check whether a catheter is needed—
is used by less than 10% of hospitals. “Until now, we haven’t had national data to tell us what hospitals are doing to prevent this common and costly patient-safety problem,” says lead author Sanjay Saint, M.D., MPH, the director of the U-M/VA Patient Safety Enhancement Program, and leader of several other studies on catheter-related issues. “Now that we have these data, it’s clear that there’s no one dominant practice that’s being used, including physician reminders, which have proven benefit and make a lot of common sense.”

Continues Saint, who is also a U-M professor of internal medicine and a research scientist at VA Ann Arbor, “The bottom line for hospitalized patients and their families is, if you have a catheter, ask the doctor or nurse every day if you really still need it.”

Source: University of Michigan Health System

Test for Respiratory Viruses Cleared by FDA

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The U.S. Food and Drug Administration today cleared for marketing a test that simultaneously detects and identifies 12 specific respiratory viruses.

The test, called the xTAG Respiratory Viral Panel, is the first test for the detection and differentiation of influenza A subtypes H1 and H3. Influenza A is the most severe form of influenza for humans, and has been the cause of major epidemics. The new panel is also the first test for human metapneumovirus (hMPV), newly identified in 2001.

The xTAG Respiratory Viral Panel amplifies viral genetic material found in secretions taken from the back of the throat in patients with possible respiratory tract infections. In the test, specific beads, or microspheres, bind to the amplified viral genetic material. The beads are then sorted so that the specific virus can be identified.

The xTAG panel is the first FDA-cleared test for infectious respiratory disease viruses that uses a multiplex platform, allowing several tests to be processed using the same sample.

"Nucleic acid tests such as the xTAG Respiratory Viral Panel utilize small amounts of genetic material, and then replicate it many times," said Daniel G. Schultz, M.D., director of FDA’s Center for Devices and Radiological Health.

"This speeds up the usual process of detecting and identifying respiratory viruses, which can take up to a week," said Schultz. "And, because this multiplex viral panel tests for 12 viruses at once, it uses less of a patient’s test specimen."

Other viruses identified by the xTAG Respiratory Viral Panel:

  • influenza B – one of three types of human influenza, less severe than influenza A
  • respiratory syncytial virus subtype A and B – both are leading causes of infant pneumonia and bronchiolitis (an infection of the airways leading to the lungs) and often contribute to the development of long-term pulmonary disease
  • parainfluenza 1, 2 and 3 – all are leading factors in the croup and the common cold
  • rhinovirus – the most common viral infective agent in humans and a cause of the common cold
  • adenovirus – a cause of respiratory tract infections often similar to strep throat or tonsilitis

While the test is faster than conventional tests, it is specific to the dozen viruses listed and should be used with other diagnostics such as patient data, bacterial or viral cultures and X-rays. Positive results do not rule out other infection or co-infection and the virus detected may not be the specific cause of the disease or patient symptoms.

The xTAG Respiratory Viral Panel is manufactured by Toronto-based Luminex Molecular Diagnostics.

Source: FDA, January 3, 2008

Flu Shot Decreases Elderly Death Risk by Half Says Study

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A recent study published in The New England Journal of Medicine indicates that seniors over 65 who get the flu vaccine cut their risk of influenza death in half, and that vaccination lowers hospitalization rates by 27 percent.

Approximately 36,000 deaths and 200,000 hospitalizations are attributed to the flu each year in the United States.

The study, lead by Dr. Kristin Nichol, from the Minneapolis VA Medical Center, was conducted on approximately 300,000 unvaccinated and 415,000 vaccinated seniors over the age of 65 from three different HMO’s over 10 years.

Interestingly, this study contradicts one that was released just last week that indicated results of flu vaccine effectiveness were exagerated. Dr. Nichol’s study attempted to address some of the discrepancies.

 

Source: The New England Journal of Medicine, October 4,
2007.

 

Taking Zinc for colds? Think Again

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In a paper by Stanford University Department of Pediatrics and Medicine, with the University of Virginia School of Medicine, and published in the Journal of Clinical Infectious Diseases, 105 published reports of zinc efficacy in warding off the common cold were studied.

Of the 105 articles reviewed, fourteen were randomized placebo-controlled studies—in other words, proper scientific studies. Of these fourteen studies, eleven featured the qualities of inquiry representative of a proper clinical trial.

In reviewing these eleven trials, the author’s concluded "this structured review suggests that the therapeutic effectiveness of zinc lozenges has yet to be established. One well-designed study did report a positive effect of zinc nasal gel."

Botulism Warning from FDA – Canned French Cut Green Beansbo

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The FDA warned consumers this week to avoid specific brands of French Cut Green beans because the beans may not have been processed properly to eliminate the potential for botulism toxin.

So far there have been no illnesses associated with the products, but the potential for serious illness exists.
Anyone who has any of the following list of beans should immediately throw them away. If you are unable to read the code on the affected cans, it is recommended to dispose of them anyway.
The affected Lakeside cut green beans are sold nationwide under the following labels: Albertson’s, Happy Harvest, Best Choice, Food Club, Bogopa, Valu Time, Hill Country Fare, HEB, Laura Lynn, Kroger, No Name, North Pride, Shop N Save, Shoppers Valu, Schnucks, Cub Foods, Dierbergs, Flavorite, IGA, Best Choice and Thrifty Maid. The specific codes (top line of can code) involved are: EAA5247, EAA5257, EAA5267, EAA5277, EAB5247, EAB5257, ECA5207, ECA5217, ECA5227, ECA5297, ECB5207, ECB5217, ECB5227, ECB5307