Flu Outbreak closes Hong Kong Schools

Outbreaks of influenza-like illness (ILI) in over 20 schools that are linked to the deaths of three children have caused the government to shut all schools in Hong Kong for two weeks, keeping half a million children away, reported Reuters.

According to information from the Center for Health Protection (CHP) of the Department of Health (DH) in Hong Kong, up to yesterday, Wednesday 12th March, health officials had received reports of 184 ILI cases in outbreaks affecting 23 schools. Officials from the CHP have visited all the schools and given appropriate advice, according to a press release on the CHP website.

ILI can be caused by influenza or other respiratory viruses, said the CHP, who will be giving out public information on seasonal influenza today. The center has also set up a hotline.

Three children, aged 2, 3 and 7 have died in the last two weeks, the older two had seasonal flu and the cause of illness in the youngest is still undetermined, said Reuters.

The government has closed the schools as a precaution because the number of young children getting the flu seems to be higher this year, Health Secretary York Chow told a press conference. The second reason was the number of deaths so far.

A fourth death was reported to the CHP yesterday, that of a 21 month old boy who developed fever and cough on February 22nd, was admitted to Alice Ho Miu Ling Nethersole Hospital the next day, and was transferred to the Intensive Care Unit (ICU) of the Prince of Wales Hospital after developing generalized seizure. He died on 22nd February. A sample taken from the boy tested negative for influenza types A and B, and there is no evidence that he had influenza, said the CHP. The case is still being investigated.

Another 3 year old boy is in a stable condition, according to the CHP who received an update on his condition yesterday, when he was admitted to the ICU at Princess Margaret Hospital with symptoms of persistent fever, cough and shortness of breath. A sample taken from him has tested positive for influenza type A (H1N1).

Health officials have visited the kindergarten the boy attended, where so far no ILI outbreak has been reported.

Giving out further information on the 7 year old boy who died in Tuen Mun Hospital after being admitted with respiratory and neurological symptoms, the CHP said a sample taken from him has tested positive for influenza A (H1N1), and the case has been referred to the Coroner's Court.

While it is natural for parents to be concerned, experts have told the press there is no cause for panic and that every few years or so there is a higher than usual incidence of flu outbreaks.

In the meantime, the Hong Kong Department of Health suggests people boost their immune system against the flu by "having a proper diet, regular exercise, and adequate rests, reducing stress and avoiding smoking". They also urge people to "maintain good personal and environmental hygiene."

Hong Kong's hotline for seasonal flu information is on telephone number 2125-1133, open Monday to Friday, 9 am to 6 pm (provided by Center for Health Protection, CHP).

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Modeling Flu Pandemics may help prevent them

An article published in the Early Edition of the Proceedings of the National Academy of Sciences in the United States of America suggests that we can reduce the likelihood of a pandemic influenza outbreak in the United States by quickly implementing social-distancing measures alongside antiviral treatment and prophylaxis (preventive measures) until a vaccine becomes accessible.

The study was conducted by three teams of researchers in the US and England who worked closely with federal officials. The teams and an informatics group - part of the Models of Infectious Disease Agent Study (MIDAS) Network, funded by the National Institute of General Medical Sciences (NIGMS) - set out to study several intervention combinations to aid the planning process for a national pandemic.

The authors, led by M. Elizabeth Halloran, M.D., D.Sc. and Ira M. Longini Jr., Ph.D., (Fred Hutchinson Cancer Research Center and professors of biostatistics at the University of Washington), investigated the natural course of infectious diseases by using sophisticated mathematical and statistical models. Longini notes that to make sure the results were robust, the federal government wanted three groups to be working on the same problem. The data, says Longini, "would be used to inform national pandemic planning," and thus they got the highest level of input.

Since a flu vaccine was not available when the researchers began the study, they focused on the effectiveness of using antiviral and social-distancing interventions (e.g. closing schools) together in order to prevent an influenza pandemic. According to earlier studies, models have shown that an available vaccine, even if low-efficacy, would be helpful in reducing the speed of a pandemic.

Halloran notes: "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."

One research team consisted of Halloran, Longini, a computer scientist Shufu Xu, and others at the Los Alamos National Laboratories. Researchers at Imperial College in London and the University of Pittsburgh comprised a second group, and a third group included researchers at Virginia Bioinformatics Institute at Virginia Tech in Blacksburg, Va.

Each research team used separate but similar computer models. They calculated how influenza would disperse in a city of about 8.6 million people, such as Chicago, IL. The models assumed that residents of the virtual community interacted in households, schools, workplaces, and the community, just as they usually do. The models all assumed attack-rate patterns that were analogous to US flu pandemics that have occurred in the past.

To take into account real-world unpredictability and several other characteristics of the disease and the population, Halloran and colleagues use stochastic modeling when predicting the spread of influenza. The first step in building pandemic models requires researchers to come up with various assumptions about the ways in which people interact and how the virus spreads. They can then introduce intervention strategies to the model in order to test how effective they are.

Two categories of intervention were assessed:

1. Medical intervention: surveillance used to identify cases, and antiviral agents are used to treat patients and prevent the disease among close contacts
2. Non-pharmaceutical: social distancing - closing schools, voluntary quarantine, restricting travel restrictions

The models allowed researchers to analyze how combinations of targeted antiviral treatment, prophylaxis, and social-distancing strategies affect five intervention scenarios of varying stringency and disease transmissibility levels. Transmissibility of the virus is calculated as the average number of secondary cases that each primary case infects at the beginning of the epidemic, and how rapidly these cases arise. These data aid the researchers in estimating the likelihood that an epidemic will become a pandemic.

The three computer simulations predict about 47 to 60 percent of the population will have symptomatic influenza if there is no intervention.

In the least-stringent scenario, interventions were implemented after 1 percent of the population had developed symptomatic influenza, schools were closed, 60 percent of clinical influenza patients received antivirals and their contacts received prophylaxis, 30 percent complied with quarantine, and 60 percent complied with social-distancing measures.

The three computer-modeling groups predict an 83 to 94 percent reduction in cases of influenza using combined intervention strategies at a lower transmissibility of the virus, even in the least-stringent scenario.

Longini maintains that the researchers "ran this simulation with the assumption that the pandemic was as virulent and lethal as the 1918 pandemic." He adds: "Even when modeling the situation of pandemic flu, with a modest compliance range in social-distancing measures, and modest ability to identify and treat and prophylax with antivirals, the interventions were similarly - though not identically - effective in all three models."

The researchers believe that the policy implications of these findings are noteworthy. "If one could achieve these levels of compliance, ascertainment and social distancing, then there is a possibility of considerably mitigating a pandemic until a vaccine was available." They caution, though, that the levels of disease ascertainment and compliance that were entered into the models may not be realistic.

"These models, which are built from the best available data and with the best tools, contribute greatly to our understanding of how a pandemic could spread and what measures might protect the public's health," said Jeremy M. Berg, Ph.D., director of the NIGMS, which supports the MIDAS program. "But they are not our only resource; field work and experimental studies remain critical and will enhance the quality and reliability of these and other models," conclude the authors.

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Macular Degeneration more than Doubles Heart Attack and Stroke Risk

Age related macular degeneration (AMD) doubles the risk of dying from a heart attack, according to research released on February 28, 2008 in the British Journal of Opthalmology.

AMD is a progressive eye diseases which affects the center of the retina, known as the macula, at the back of the eye. This portion of the eye is most specialized for fine, central vision tasks, including reading or driving. It is most common among the elderly, and in developed countries it is a major cause of untreatable blindness.

An Australian team of researchers at the University of Sydney analyzed over 3600 people aged 49 years or more between 1992 and 1994. Five years later, a follow up was performed on 2335 of these people; after ten years, 1952 were examined again. The analysis included physical examinations and photographs of the retina itself -- the causes of death of participants during the study was also noted based on the national register.

Of the population under age 75 who participated in the study, early presentation of AMD was linked to a double in the risk of death from heart attack or stroke within a decade. The late stage disease was associated with a five fold increase in death from heart attack and ten time the risk of death from stroke.

As there are some concerns that current treatments for AMD could elevate stroke risk, these results have extremely important implications for the treatment of this disease in the elderly.

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PSA less useful in Prostate Screening now Biopsies have improved

Researchers in the US suggest that the prostate specific antigen (PSA) test is now less useful in prostate cancer screening, and may have lost some of its predictive value, because biopsy techniques have improved in the ten years or so since the research that justified the use of PSA as a diagnostic tool was done.

The study is the work of Drs. Douglas Scherr and Michael Schwartz, and colleagues at the New York Presbyterian Hospital of the Weill Medical College of Cornell University, based in New York City, and is published in the 10 March online issue of the journal Cancer.

The correlation between PSA levels and positive prostate biopsy results was established at a time when biopsy patterns were not as they are today. Much of the data to justify the PSA test as a useful diagnostic tool was generated in the 1990s. Today, more biopsies are taken, and more samples are taken from each patient.

Scherr, Schwartz and colleagues examined data on 1,607 patients whose prostate biopsies were carried out at their hospital between 1993 and 2005 and grouped them according to when they received their biopsies: 1993-1997, 1998-2001, and 2002-2005. They then looked for how patterns of practice, and correlation between PSA and biopsy results shifted with time.

Using the number of biopsies performed, the number that were positive, the number of biopsy samples taken, the age of the patient, the most recent PSA before the biopsy and the volume of the prostate, the researchers assessed the potential links between PSA levels and the rate of positive biopsies.

They found that:

* The number of biopsies performed, the percentage of positive biopsies, and patient age did not change significantly over time.

* But there was more frequent use of PSA level 2.5 to 3.99 ng/ml as a biopsy indication (ie tendency toward lower PSA threshold).

* And there was an increase in the median number of core samples taken at the time of the biopsy.

* In men with a normal digital rectal exam, there was a moderate correlation between PSA level and positive biopsy rate between 1993 and 1997, but not after that.

* Fewer biopsies were performed for the indication of a suspicious digital rectal exam.

* The positive biopsy rate in men with PSA levels between 2.0 and 3.99 ng/ml was the same or higher than that for men with higher PSA levels.

* Multivariate analysis showed that PSA was not a significant predictor of biopsy result in men with a normal digital rectal exam.

The researchers concluded that:

"Early in the PSA era, the predictive power of PSA depended on multiple factors: high prevalence of disease, higher prevalence of high-grade disease, and low likelihood of prostate cancer diagnosis in men with low PSA."

But today, because of the "culling effect" of more frequent biopsies and shifts in biopsy patterns, they said that:

"The correlation between PSA and biopsy result is lost in men with normal DRE [digital rectal exam]," and that "diagnosing a higher proportion of tumors in men with a PSA between 2.0 and 4.0 ng/mL has negatively influenced the predictive value of PSA for cancer detection".

According to the American Cancer Society, the PSA level normally goes above 4 ng/ml when cancer is present, but around 15 per cent of men with a PSA under 4 will have prostate cancer.

Scherr told WebMD that whether the PSA level was as low as 2.5 or as high as 10, the chance of finding cancer was about the same in the men who had biopsies, so the usefulness of using PSA to find the men who need biopsies has been lost, he said, especially given that the prostate cancers they are finding are also smaller.

The researchers said there was an urgent need for new blood or urinary markers to predict who should have a prostate biopsy, because apart from family history or signs from previous biopsy results, there is little help available to give doctors a clue as to who should be referred for a prostate biopsy.

Dr. Robert Smith, Director of Screening at the American Cancer Society told WebMD that while PSA is an imperfect test, it "happens to be the best one we have at the moment", and that:

"Because of the uncertainties, leading cancer organizations, including ACS, recommend that men discuss the pros and cons of this test with their doctors."

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Hope for Crohn's Patients with Fistulas found in HUMIRA/Adalimumab

At the recent European Crohn's and Colitis Organization (ECCO) annual meeting in Lyon, France, Abbott Laboratories announced that HUMIRA (Adalimumab) is successful in the treatment of fistulas in susceptible Crohn's patients.

Crohn's Disease (CD) is a gastrointestinal disorder which is indicated by chronic inflammation of the wall of the digestive tract. The disease involves constant cycles of flare-ups and remission throughout the life of the patient, and without proper treatment, must be addressed surgically. It is considered an inflammatory bowel disease (IBD), similar to ulcerative colitis. Up to 43% of Crohn's disease patients develop painful and embarrassing fistulas, which are tunnels that connect affected organs to surrounding tissues such as the bladder, vagina, or skin. These are difficult to treat, can cause fecal discharge in abnormal locations, and can thus lead to incontinence, infections, and complications that will necessitate surgery.

HUMIRA, or Adalimumab works by binding Tumor Necrosis Factor α (TNF-α), an important part of the immune response pathway -- in this way it is related to infliximab and other TNF-α blockers. It has been approved in several countries for treatment of many autoimmune diseases including CD, psoriasis, and certain types of arthritis. Abbott Labs is also studying HUMIRA in pediatric CD.

The fistula study was based on data taken in the CHARM study. In a subanalysis, it was shown that fistula healing was improved with treatment with HUMIRA:

* 60% of patients experienced fistula healing at one year of treatment
* 76% of patients who experienced healing at one year sustained the healing through two years
* 71% of patients demonstrated a 50% reduction in the number of draining fistulas after two years of treatment

Over a two year term, fistula patients had a higher quality of life because the CD was in remission, defined as scoring greater than 170 points on the Inflammatory Bowel Disease Questionnaire (IBDQ): after 1 year, 54% of patients and after 2 years, 60% of patients achieved this score.

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