Influenza Virus Mashup

(Thu, 26 Aug 2010 18:07:00 +0000)

# 4836

One of the downsides to employing averages, rule’s of thumb, and oversimplified but `friendly’ data is that it can skew the public’s perception of what is `normal’ or expected.

A prime example is the oft stated statistic that 36,000 Americans die each year from an influenza-related illness. 

It’s an easy and convenient `factoid’ that the media can slip into a news report, but it isn’t a completely reliable number.

As I’ve mentioned in the past, that number is an estimate . . . not an actual count . . . and it can be a bit misleading because it is an average of estimated deaths that occurred during the 1990s – a number that was calculated as ranging from a low of 17,000 to a high of 52,000.

None of this is hidden knowledge, of course.  The CDC has readily stated how they came up with their estimates, and those methods have been the subject of considerable debate.

While everyone wants good numbers, there are a number of obstacles in the way of any attempt to accurately estimate flu-related deaths.

Including: 

• Estimates are extrapolated based on a surveillance subset of the country, not the whole nation
• There are often co-circulating viruses that may influence overall mortality.
• Surveillance, testing, and reporting may change over time
• Different mathematical models can produce differing results
• There are varying opinions as to what constitutes an influenza-related fatality.

When combined with the inevitable variations in the severity of influenza seasons (H3 years are usually more severe than H1 years), this makes it impossible to derive a single number that `works’.

In an attempt to help us better understand the impact of influenza-related deaths in the United States each year, the CDC has released a new study in today’s MMWR  titled:

Estimates of Deaths Associated with Seasonal Influenza — United States, 1976–2007

Weekly

August 27, 2010 / 59(33);1057-1062

There is a lot of data here, as deaths are divided into two broad camps ( 1) pneumonia and influenza causes and 2) respiratory and circulatory causes), and further divided by three age brackets (<19 years, 19–64 years, and ≥65 years)

For deaths with underlying pneumonia and influenza causes (the most narrow definition of flu-related fatalities used) the models estimated a yearly average of 6,309 (range: 961 in 1986–87 to 14,715 in 2003–04) influenza-associated deaths.

 

Using a broader criteria (underlying respiratory and circulatory causes including pneumonia and influenza causes)  the models estimated an annual average of 23,607 (range: 3,349 in 1986–87 to 48,614 in 2003–04) influenza-associated deaths.

Somewhat less than the old 36,000 number, but explained in the report as that number having been based on estimates derived during the 1990s – when H3N2 was the predominant strain.

These new numbers are based on 31 influenza seasons, running 1976-2007.

The short course  from the study is as follows. 

What is already known on this topic?

Influenza infections result in substantial medical costs, hospitalizations, lost productivity, and thousands of deaths every year in the United States with the majority of deaths from seasonal influenza occurring among adults aged ≥65 years.

 

What is added by this report?

During 1976–2007, annual estimates of influenza-associated deaths from respiratory and circulatory causes ranged from 3,349 (in 1986–87) to 48,614 (in 2003–04), and the annual rate of influenza-associated death for all ages ranged from 1.4 to 16.7 deaths per 100,000 persons; during seasons when influenza A(H3N2) circulating strains were prominent, 2.7 times more deaths occurred compared with seasons when A(H3N2) was not prominent.

 

What are the implications for public health practice?

A single estimate should not be used to summarize influenza-associated deaths; a range of estimates should be described in the context of circulating virus strains and underlying causes of death among age groups. Annual influenza vaccination (now recommended for all persons aged ≥6 months) is the best way to avoid influenza complications, and prompt treatment with antiviral medications can reduce the risk for severe illness and death among persons at increased risk for influenza or who are hospitalized with influenza.

Since statistical analysis isn’t my strong suit, I’ll leave it to others to try to analyze these findings and methods.

By just about any calculation, however, influenza is a serious illness that exacts a heavy toll on society.  Which makes getting the yearly flu vaccine a smart move.

By all means, follow this link to read the report in its entirety.

Thanks to Mike Coston who passed along a heads-up about this story. Via Al-Masry Al-Youm: Egypt announces 36th bird flu death. Excerpt:

Egypt announced Thursday its 36th death linked to the H5N1 virus, commonly referred to as avian or bird flu. 

The 33-year-old victim, a woman from Qalyubiya, was hospitalized in Cairo Wednesday after experiencing a high fever and difficulty breathing. The Ministry of Health suspects she contracted the virus through contact with infected poultry. 

The World Health Organization says Egypt ranks third globally in H5N1 documented cases. The majority of the cases in Egypt have come as the result of close contact with infected domestic poultry. 

Approximately five million Egyptian families depend on poultry as an important source of food and income.

The report goes on to say that 16,000 persons have contracted bird flu and over 265 have died of it. That’s first a gross error and second an understatement. WHO’s latest tally, publish August 12, shows 504 confirmed human H5N1 cases and 299 deaths. This makes 505 and 300.

(Thu, 26 Aug 2010 16:01:00 +0000)

# 4835

The announcement yesterday of the 112th human infection by bird flu in Egypt (see KUNA: Egypt Announces 112th Bird Flu Infection) indicated that the patient – a 33 year-old woman – was in critical condition.

Today, sadly, we learn that she has died.   

A hat tip to Twall on FluTrackers for the heads up on this story.

Health announces the ninth bird flu death in 2010

Thursday, August 26th, 2010 - 13:23

Written by Amira Abdel-Salam

Ministry of Health announced today, Thursday, for the death of ninth case of bird flu during the year 2010, which is of a woman Qaliubiya old 33 years old.

It is noteworthy that since the issuance of the disease in 2006 cases amounted to 112 cases of infection, while reaching deaths to 36.

Via Radio New Zealand: Swine-flu related death toll now 15. Excerpt:

The number of deaths in New Zealand this year linked to swine flu has climbed to 15. 

Five deaths from the Auckland and Waitemata district health board areas have been recorded this week.
Meanwhile, Hawke’s Bay is experiencing the highest rate of influenza-like illness. 

Despite this, the Ministry of Health says some regions - particularly in the North Island - may be starting to see a decline in the number of cases of swine flu, also known as the H1N1 virus. 

However, the ministry says it is too early to tell whether this is the start of a downward trend. 

To date, 583 people have been hospitalised with the H1N1 virus this year, including 91 cases referred to intensive care.

Yesterday Ida at Bird Flu Information Corner reported a B2B H5N1 outbreak in chickens. Today she has a follow-up: Pamekasan, East Java ::: Bird flu not transmitted to people. Excerpt:

Health Service of Pamekasan ensured bird flu H5N1 is not transmitted to chicken owner and neighbours. 

“Medics have examined people who had direct contact with dead chickens. And they are clear,”said Head of Health Service, Hendro Santoso, Thursday (26/08).

(Thu, 26 Aug 2010 12:45:00 +0000)

# 4834

The shell egg recall over possible Salmonella-related contamination continues to grow, with a 23rd state (Michigan) now involved.  Lisa Schnirring writing for CIDRAP News has the latest, after which I’ll return with some FDA and CDC resources.

 

States affected by egg recall grow to 23

Lisa Schnirring Staff Writer

Aug 25, 2010 (CIDRAP News) – Agriculture officials in Michigan said yesterday that eggs connected to the national Salmonella-related recall have been distributed in the state, though it wasn’t mentioned in recall notices by the two Iowa companies at the center of the investigation, Wright County Egg and Hillandale Farms.

 

The Michigan Department of Agriculture said in a statement that an ongoing traceback investigation has revealed that some of the companies’ customers are distributors and wholesalers that sold the eggs to Michigan customers.

 

Michigan’s announcement raises the number of states affected by the recall to 23, according to a review of company recall notices. The two companies have recalled about 500 million eggs. Four smaller companies that repackaged and resold the eggs from the two companies have also issued recalls.

(Continue. . . )

The FDA maintains a webpage on this recall, and continually adds new resources and links.

Recall of Shell Eggs

Updated August 26, 2010

Topics on this page:

• Introduction
• Identifying Recalled Brands and Products
• News Updates
• Consumer Health Information
• Information about Egg Safety and Salmonella
• Investigation into the Salmonella and Shell Egg Outbreak

---

Introduction

An outbreak of Salmonella Enteritidis (SE) that has sickened hundreds of people across the country has led to a recall of shell eggs. On August 13, Wright County Egg voluntarily conducted a nationwide recall of shell eggs on 3 of its 5 farms. Further epidemiologic and traceback information led to Wright County Egg expanding its recall on August 18 to cover all 5 farms and 380 million eggs (according to company figures). The FDA is monitoring the recall, including conducting audit checks at retail stores, wholesalers, and distributors to make sure the recalled shell eggs are being removed from the market. The FDA is in ongoing communications with Wright County Egg to ensure that appropriate preventive measures are put in place to reduce the risk of recurrence.

(Continue . . . )

The CDC meanwhile offers some advice on how to limit your chances of contracting Salmonella  Enteritidis from shell eggs on their Tips to Reduce Your Risk of Salmonella from Eggs webpage.

What are the specific actions I can take to reduce my risk of a Salmonella Enteritidis infection?

1. Keep eggs refrigerated at ≤ 45° F (≤7° C) at all times.
2. Discard cracked or dirty eggs.
3. Wash hands, cooking utensils, and food preparation surfaces with soap and water after contact with raw eggs.
4. Eggs should be cooked until both the white and the yolk are firm and eaten promptly after cooking.
5. Do not keep eggs warm or at room temperature for more than 2 hours.
6. Refrigerate unused or leftover egg-containing foods promptly.
7. Avoid eating raw eggs.
8. Avoid restaurant dishes made with raw or undercooked, unpasteurized eggs. Restaurants should use pasteurized eggs in any recipe (such as Hollandaise sauce or Caesar salad dressing) that calls for raw eggs.
9. Consumption of raw or undercooked eggs should be avoided, especially by young children, elderly persons, and persons with weakened immune systems or debilitating illness.

Who is most at risk for getting Salmonella Enteritidis?

The elderly, infants, and those with impaired immune systems may have a more severe illness. In these patients, the infection may spread from the intestines to the blood stream, and then to other body sites and can cause death unless the person is treated promptly with antibiotics.

How do I know if I have Salmonella Enteritidis?

A person infected with the Salmonella Enteritidis bacterium usually has fever, abdominal cramps, and diarrhea beginning 12 to 72 hours after consuming a contaminated food or beverage. The illness usually lasts 4 to 7 days, and most persons recover without antibiotic treatment. However, the diarrhea can be severe, and the person may be ill enough to require hospitalization.

CIDRAP has published its August 25 NEWS SCAN: H5N1 in Egypt, H1N1 patterns in China, dengue advisory. As always, it’s concise and informative.

Via ABC News: Flu spike on the way, experts warn. Excerpt:

This year’s flu season has been late, but influenza experts say people should brace themselves for some potent strains of the disease. 

Last winter it was predicted that hundreds of thousands of people could be affected by the swine flu virus. 

While those numbers did not eventuate, many people still felt the ill-effects of the flu and experts are warning it is on its way back. 

Virologists keep a close eye on New Zealand to see what flu strain is going to hit Australia next. 

The head of the Influenza Specialist Group, Doctor Allan Hampson, says the flu season has arrived later than expected and the number of cases is continuing to climb. 

“We’re seeing increasing levels of influenza levels in New Zealand over the last three weeks,” he said. 

“We normally follow New Zealand by a couple of weeks, so that’s a good indication of what’s to come.” 

It is estimated almost 3,000 Australians die from influenza-related causes every year. 

Dr Hampson says the threat remains as serious as ever and there is still a strong risk from the swine flu. 

“The virus that’s predominant at the moment is the same one that we had last year, the so-called swine flu,” he said. 

“But there is a second or even a third virus actually in the community at the moment and we’re not sure just to what extent they will be predominant or whether the swine flu will continue to predominate in Australia.” 

Last year, the swine flu caused worldwide panic. 

Dr Hampson says it differs from most flu viruses because it affects many people who are usually not considered at risk. 

“It tends to attack younger people than we’re used to with influenza,” he said. “The severe cases and the deaths have occurred in people who don’t appear to have any underlying risk condition.” 

Pregnant women and people of Aboriginal and Torres Strait Islander backgrounds are considered to be at extra risk.

Via Al-Masry Al-Youm: Health Ministry announces Egypt’s 122nd case of bird flu. But I suspect it’s a typo for “112th.” Explanation after the excerpt:

The Health Ministry on Wednesday announced the appearance of another case of the H5N1 virus, bringing the total number of documented cases in Egypt to 122 since the virus–also known as avian or bird flu–first emerged in 2006. 

The patient, a female resident of  the Qalyubiya Governorate, is currently receiving treatment at a Cairo hospital. 

According to a ministry statement, her symptoms include high fever and breathing difficulties. She contracted the illness after coming into contact with poultry suspected of having been infected with the virus, the statement noted, adding that she remained in critical condition despite having been treated with the anti-viral drug Tamiflu on arrival to the hospital. 

The last time an Egyptian succumbed to the H5N1 virus was in April. That case brought the total number of bird flu fatalities in Egypt to 34.

WHO’s last situation update on H5N1 in Egypt was on August 12, describing a two-year-old who was the country’s 111th confirmed case. That update also mentioned 35 H5N1 deaths so far. So unless the Egyptian authorities have been concealing 10 cases, this young woman is case #112.

(Wed, 25 Aug 2010 18:36:00 +0000)

# 4833

From the Kuwaiti News Service, KUNA today, we have this brief announcement of a new human infection by the H5N1 virus in Egypt.

I’ve run the original Arabic through the Google Translator (this link) to produce the following:

Egyptian Ministry of Health declares human infection with bird flu, No. 112

 

Health 08/25/2010 5:39:00 PM

Cairo - 25-8 (KUNA) - Ministry of Health announced today that No. 112 of human infection with bird flu since the disease appeared in Egypt, noting that they belong to a woman, aged 33, from Qaliubiya described her condition critical.

 

 

The ministry said in a press statement that the woman, who introduced a Cairo hospital on Thursday suffering from high temperature, cough and difficulty breathing after exposure to birds suspected of being affected by bird flu.

This is the second human case in Egypt this month, with case #111 reported on here.  

Sporadic human infections with the H5N1 avian flu virus continue to be reported in a handful of countries around the globe.  Most (but not all) have been linked to close contact with infected poultry or birds.

The bird flu virus has yet to adapt well enough to human physiology to transmit effectively between people, although scientists warn that H5N1 could mutate into a pandemic strain someday.

The world remains in Pre-Pandemic Phase III on H5N1, and so monitoring and reporting on this virus remains vital.

Note: A hat tip to Pandemic Information News  for the heads up on this story.