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> Внимание. Обязательно к прочтению!, если не утка конечно
probegallo |
Дата 26 Марта, 2005, 9:36
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US flu vaccine trials may be effort wasted
12:30 25 March 2005


The first human trials of a vaccine against H5N1 bird flu are likely to be a waste of time and money.

The formulations that the US plans to test are thought likely to be ineffective - and even if they do work it will take far too long to manufacture enough doses to prevent a pandemic strain wreaking havoc. Other countries are following more promising approaches, but they are not ready to start trials.

Fears that the H5N1 virus might mutate into a form capable of triggering a human pandemic have persuaded several countries to change strategy. Instead of waiting for a pandemic strain to emerge, health authorities are creating human vaccines against the current strain. Although these vaccines might not be perfect, the hope is that they will make the difference between life and death.

The sooner prototype vaccines are tested, the sooner vaccine makers can prepare to manufacture the vast quantities that might be needed. But so far the US is the only country to have ordered enough prototype vaccine to do clinical trials - and there are two major problems with its formulations.
No immunising effect

The key ingredient in any flu vaccine is the viral protein haemagglutinin, or HA. Vaccines against ordinary flu contain 15 micrograms each of three varieties of HA. The clinical trials planned by the US National Institute of Allergy and Infectious Diseases will test doses of 15 and 45 micrograms of H5 - the HA of the H5N1 virus killing people in Vietnam. The aim is to make the vaccine as similar to ordinary flu vaccines as possible, to ease approval by the FDA.

But several studies have shown that with HAs that people have not been exposed to before, such as H5, even doses higher than 15 micrograms have little or no immunising effect. "I predict they won't get much immune response at all," says Tony Colegate of the vaccine company Chiron in the UK, head of the industry's pandemic task force.

For this reason, other countries planning to test prototype vaccines - like Japan, Canada and Australia - will all add a chemical such as alum to boost the immune system reaction. This adjuvant is used in many childhood vaccines.

Another important benefit of adding an adjuvant is that far less HA will be needed in each dose. That is crucial because vaccine production capacity is limited.
Worldwide capacity

The single flu vaccine factory in the US would take six months to produce 180 million doses of 15 micrograms of H5, according to calculations by flu expert David Fedson in the latest issue of the Journal of Public Health Policy. And since past studies suggest people need two shots three weeks apart to develop immunity to novel strains, that is enough for only 90 million people. All vaccine plants worldwide could produce only enough for 450 million people.

In 2001, however, scientists in the UK found that with an adjuvant, two doses of just 7.5 micrograms of H5 were enough to induce immunity in previously unexposed people. And last year scientists at GlaxoSmithKline Biologicals found that two doses each of 1.9 micrograms of another novel HA were enough.

If a vaccine could be made with just 1.9 micrograms per dose, the world's vaccine plants could churn out 7.2 billion doses in six months, enough for 3.6 billion people, Fedson says. "That's probably more than the world's combined healthcare services can vaccinate."

Bruce Gellin, head of the US National Vaccine Programme Office, says the trials now being planned "are only the first in a long series". Last week his department asked for proposals to find ways to make vaccines stretch farther, he says. "We are taking this very seriously."

Journal reference: Journal of Public Health Policy
probegallo |
Дата 27 Марта, 2005, 18:38
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United Kingdom: Emergency services plan for 750,000 deaths in flu pandemic


By Geoffrey Lean and Severin Carrell

27 March 2005

Mortuaries and emergency services are to be put on alert and told to prepare for up to three-quarters of a million deaths from a bird flu pandemic, The Independent on Sunday can reveal.

Emergency planners have begun to look for sites for special mortuaries, each capable of storing 1,000 bodies, and the Home Office is to hold an exercise this summer to practise coping with mass fatalities. The instruction, to go out from the Civil Contingencies Secretariat, the Cabinet Office body in charge of emergencies, explodes the Government's public position that the pandemic could be expected to kill only "around 50,000" people in Britain.

It shows that its true expectation is closer to the prediction made by Professor Hugh Pennington, the president of the Society for General Microbiology, in The Independent on Sunday two weeks ago that up to two million Britons could perish. The Secretariat also believes that a quarter of the country's workforce could fall ill, paralysing economic life.

A senior government official told a private seminar in London last week: "It may be somewhere between 20,000 and 750,000 extra deaths and it may be 25 per cent of the population off work. That is the shape of the event we are going to have to deal with."

He added that plans had been drawn up to confirm that emergency services and coroners had the staff and equipment to cope with such a crisis. Senior emergency planners said last week that they received official instructions at the end of last year to prepare for mass mortuaries to cope with a flu pandemic or a biological terrorism attack.

They said that most police authority areas normally had emergency mortuaries to hold 100 to 200 bodies, but they had now been asked to make provision for up to 1,000.

The authorities were now identifying greenfield sites and beginning to enter into contracts with firms to provide marquees and buildings to put on them. The planners said that these would be cooled to about the same temperature as household refrigerators, to store bodies.

The scale of the preparation suggests that the Government fears that the 14.6 million doses of anti-viral drugs it has ordered may not arrive before a pandemic. Even in a year's time, less than half of the order will have been met. The drugs have been delayed partly because ministers waited for months before making the order.

Last November an official flu exercise involving health bodies, emergency services and government - Exercise Icarus - identified the lack of anti-viral drugs as a key concern. The order was placed this month.

Dr John Simpson, of the Health Protection Agency's emergency response division, said the Government was planning more exercises, including preventing public gatherings, to stop the disease spreading.

Senior officials at the World Health Organisation (WHO) told the IoS that they predict the flu virus could circle the globe within two months.
WereWolf | Профиль
Дата 28 Марта, 2005, 11:31
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А вообще то я добрый
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probegallo |
Дата 29 Марта, 2005, 2:45
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Краткая выжимка из статей на этой странице
1. Лекарств, которые могут реально помочь при птичьем гриппе, очень мало как таковых и они дороги и их производиться в мире ограниченное количество. Одним из таких является озельтамивир (он же Тамифлю), но его одна упаковка (на курс) стоит около 50-60$. До конца этого месяца Канада запасется примерно 20 млн. таблеток (примерно на 2 млн. чел.), но так как этого очень мало, то они решили вывделять лекарство в зависимости от важности соц. группы, к которой принадлежит человек.

--Примечание: речь идет не о симптоматических средствах, которые обычно применяются при гриппе, и которые лишь несколько облегчают состояние больного во время болезни, а именно о лекарствах, которые непосредственно влияют на вирус (о вакцинах позже упомяну). Таковых действительно мало - это такие как ремантадин (ухудшает условия для проникновения вируса в клетку) и рассматриваемый в статье Тамифлю (ухудшает условия для вирусов, расплодившихся и высвобождающихся из зараженной клетки). Ремантадин сейчас довольно малоэффективен - из-за его широкого применения вирусы так или иначе довольно быстро учатся обходить это препятсвие (хотя возможно на вирусы птичьего гриппа поначалу он будет влиять сильнее чем на обычный). Тамифлю в этом отношении пока заметно более эффективен, но при широком применении возможно повторит судьбу ремантадина (т.е. эффективность его снизиться в несколько раз). Дороговизна и малодоступность Тамифлю вероятно и объясняется желанием обеспечить его эффективность - тогда минимальна вероятность возникновения штаммов вируса, на которых Тамифлю не будет действовать.

2. Официальные прогнозы по количеству погибших британцев - до 750 000 чел. Но проф. Пеннингтон прогнозирует 2 млн. погибших британцев. На закупку Тамифлю выделяется 380 млн. баксов.

3. Статья о необходимости подготовки своей имунной системы к возможной пандемии, так как для выживания важен будет каждый доп. фактор - ну в общем типичный набор: здоровый образ жизни и натурпродукты, отсутствие стрессов и т.п. Надеятся на обычное медобслуживание не стоит - когда больницы и госпитали будут переполненны заболевшими, там тебя скорее всего встретят словами: "Иди домой и умри!" :-)

4. Проходящие сейчас испытания вакцина от птичьего гриппа могут оказаться напрасными - стандартное количество одной дозы в 15 мкг может оказаться недостаточно, чтобы имунная система распознала вирус и выработался иммунитет. Поэтому тестироваться будут и дозы в 45 мкг. Однако даже если 15 мкг на дозу хватит, все равно все имеющиеся в мире предприятия смогут выработать за полгода вакцины только для 450 млн. чел. В связи с этим, планируюстя также испытания вакцины в самой минимальной дозировке в 1,9 мкг при одновременном стимулировании имунной системы другими препаратами - тогда возможно такой дозировки и хватит для выработки имунного ответа. При дозе 1,9 мкг производственных мощностей в мире за полгода хватит на 3,6 млдр. чел.
--Примечание: неэффективность вакцины может быть быть не только из-за малой дозировки - сам вирус птичьего гриппа меняется очень быстро, и скорее всего вакцина будет быстро устаревать. Какой-то толк от нее конечно будет, но вопрос какой.

5. Опять обсуждается возможные количества тех, кто погибнет в Британии от птичьего гриппа (оценки 50 или 750 тыс. - официальные, 2 млн. - неофициальные). В связи с планируемым очень большим количеством смертей обсуждается проблема размещения и утилизации трупов - в официальной инструкции говорится о необходимости специально подготовить к концу года морги для такого количества.
probegallo |
Дата 30 Марта, 2005, 23:09
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Российские ученые разработали модель распространения вируса "птичьего" гриппа и продемострировали на примере Гонконга.
29 марта 2005 года, 13:01
Текст: Эльвира Кошкина

Математическая модель распространения вируса "птичьего гриппа" была разработана в институте эпидемиологии и микробиологии имени Н.Ф. Гамалеи. В качестве примера ученые использовали гипотетическую ситуацию с возможностью распространения "птичьего" гриппа в Гонконге (около семи миллионов жителей). Модель демонстрирует, что если такая эпидемия произойдет, она продлится четыре месяца и может охватить до двух миллионов человек. На 78-й день, в пик эпидемии, число заболевших может достичь 365000 человек, а количество заражавшихся ежедневно составляло бы 118000 жителей города. Сделать прогнозы относительно возможной смертности "в рамках модели" среди заразившихся вирусом "птичьего" гриппа микробиологи затруднились.

Пока вирус "птичьего" гриппа не передается от человека к человеку, сообщает РИА "Новости". Веротяность его мутации существует, но этого может никогда не произойти. Как сообщил глава лаборатории эпидемиологической кибернетики института Борис Боев, за последние несколько лет в Таиланде, Вьетнаме и Китае было зарегистрировано несколько десятков случаев заражения людей этим видом гриппа непосредственно от домашней птицы. Умерли в этих случаях около 60% заболевших.

Добавлено в 23:12
ВОЗ: грипп может возвратиться в Россию

08:52 30.03.2005

Всемирная организация здравоохранения (ВОЗ) прогнозирует вероятность возникновения пандемии гриппа в 2005 году. Как сообщает Медновости.Ру, об этом заявил накануне академик, вице-президент РАН Рем Петров.

«Неделю назад ВОЗ сообщила, что в предстоящем эпидсезоне существует вероятность возникновения гриппа, который вызовет пандемию», — сказал Петров. Он уточнил, что речь идет о новом типе гриппа — так называемом «птичьем гриппе».

Петров отметил, что вообще вирус гриппа является самым «неприятным» из всех видов ОРЗ, поскольку он легко передается воздушно-капельным путем, вызывая эпидемии, а также обладает очень высокой генетической изменчивостью. Так, в нынешнем году, по словам Петрова, в Россию придет новый штамм гриппа, отличный от того, который был в 2004 году. «По сообщению ВОЗ, сейчас движется штамм «Калифорния», — сказал академик.

По данным ВОЗ, каждый взрослый человек болеет ОРЗ в среднем два раза в год. В России ежегодно фиксируется более семи миллионов случаев заболевания гриппом. Причем эпидемии данного заболевания нередко приводят к серьезным осложнениям. Так, на долю гриппа приходится до 6 процентов летальных исходов.

Петров сообщил, что в текущем сезоне основная эпидемия гриппа закончена, а ОРЗ идет на убыль. «Однако при такой весне ОРЗ могут еще затянуться», — заключил академик.

Напомним, что в связи с возможной пандемией гриппа Главный государственный санитарный врач России уже объявлял санэпидслужбам готовность номер один.
probegallo |
Дата 1 Апреля, 2005, 16:56
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МЧС: В Россию возможно проникновение птичьего гриппа

Обновлено 01.04 13:22
Версия для печати | PDA/КПК

Министерство по чрезвычайным ситуациям РФ предупреждает о возможности проникновения в Россию птичьего гриппа, сообщает РИА "Новости". Угроза появления в стране смертельно опасного вируса связана с тем, что в ряде стран Азии продолжается его циркуляция.

По данным Всемирной организации здравоохранения (ВОЗ), за период с 26 января 2004 года по 28 января 2005 года зарегистрированы 54 случая заболеваний людей "птичьим гриппом" в мире: в Таиланде - 17 случаев, 12 летальных исходов, во Вьетнаме - 37 случаев, 29 летальных исходов. Как отмечали в ВОЗ, эти факты свидетельствуют об изменении биологических свойств птичьих вирусов в сторону усиления патогенности для птиц и людей.

Между тем, в российском институте эпидемиологии и микробиологии имени Н.Ф. Гамалеи разработана математическая модель распространения вируса "птичьего" гриппа. Как сообщил ранее на пресс-конференции глава лаборатории эпидемиологической кибернетики института Борис Боев, в качестве примера ученые использовали гипотетическую ситуацию с возможностью распространения "птичьего" гриппа в Гонконге (около семи миллионов жителей).

Согласно модели, если такая эпидемия произойдет, она продлится четыре месяца и может охватить до двух миллионов человек. В пик эпидемии - на 78 день - число заболевших может достичь 365 тысяч человек, а ежедневно заражалось бы до 118 тысяч жителей города. Отвечая на вопрос о возможной смертности "в рамках модели" среди заразившихся вирусом "птичьего" гриппа, Боев отметил, что число погибших пока еще сложно спрогнозировать. "Вирус пока не передается от человека к человеку. Он может мутировать завтра, а возможно никогда", - сказал ученый.

Напомним, инфекция подошла практически вплотную к границам страны - Северная Корея подтвердила информацию о вспышке птичьего гриппа на птицефабриках близ Пхеньяна, в настоящее время там работает группа экспертов ООН, помогающая властям взять эпидемиологическую ситуацию под контроль.

ВОЗ считает возможной пандемию гриппа в 2005 году - Mednovosti.ru, 29.03.2005
В США начались испытания вакцины от птичьего гриппа на людях - Mednovosti.ru, 24.03.2005
На российских птичницах проведут эксперимент - Mednovosti.ru, 03.02.2005
В России появится лаборатория по особо опасному гриппу - Mednovosti.ru, 02.02.2005
probegallo |
Дата 2 Апреля, 2005, 2:34
Quote Post


Order OKs bird flu quarantine in U.S.

Associated Press

WASHINGTON - President Bush signed an executive order Friday authorizing the government to impose a quarantine to deal with any outbreak of a particularly lethal variation of influenza now found in Southeast Asia.

The order is intended to deal with a type of influenza commonly referred to as bird flu. Since January 2004, an estimated 69 people, primarily in Vietnam, have contracted the disease. But Dr. Keiji Fukuda, a flu expert at the Centers for Disease Control and Prevention, has said he suspects there are more cases.

The fatality rate among those reported to have the disease is about 70 percent.

Health officials around the world are trying to monitor the virus closely because some flu pandemics are believed to have originated with birds.

Bush's order was described as a standby precaution, adding pandemic influenza to the government's list of communicable diseases for which a quarantine is authorized. It gives the government legal authority to detain or isolate a passenger arriving in the United States to prevent an infection from spreading.

The authority would be used only if the passenger posed a threat to public health and refused to cooperate with a voluntary request, the Health and Human Services Department said.

The quarantine list was amended in 2003 to include SARS, severe acute respiratory syndrome, which killed nearly 800 people in 2003. Other diseases on the list are cholera, diptheria, infectious tuberculosis, plague, smallpox, yellow fever and viral hemorrhagic fevers.

Quarantine and isolation were last used during the SARS outbreak in 2003.
probegallo |
Дата 2 Апреля, 2005, 20:04
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Хм, поку тут птичий грипп в ЮВа раскачиваецца, Марбугская лихорадка (почти то же самое, что и Эбола), в Европе уже:


Смертельная лихорадка Марбург добралась и до Европы. По данным Всемирной организации здравоохранения, в Италии сегодня выявили 9 человек – носителей вируса.

Ранее врачи считали, что за пределы Анголы эпидемия не выйдет. Но теперь гемморагическая лихорадка Марбург стала бедствием международного масштаба. Никаких лекарств и вакцин против нее пока не существует, и в этом она похожа на другую смертельную болезнь – лихорадку Эбола. Пока из 150 человек, заболевших лихорадкой в провинции Уиже в Анголе, умерли 142. И это только официальные данные. Как сообщает ИТАР-ТАСС, по данным ангольских властей многие больные отказываются от госпитализации. Они считают, что врачи все равно не могут им помочь и предпочитают умирать дома. Смерть наступает от внезапного внутреннего и внешнего кровотечения и выжить получается только человеку с достаточно крепким организмом, способным перенести большую потерю крови.

probegallo |
Дата 2 Апреля, 2005, 20:23
Quote Post


Хм, очень примечательно -

Особенность вируса Эбола состоит в том, что он, по-видимому, имеет в природе форму, безопасную для человека, и лишь крошечные мутации величиной всего в одну-две нуклеотидные "буквы" периодически делают его вирулентным, переводя в ранг смертельных инфекций. Работая над вакциной, мы создали модель таких мутаций, получили генно-инженерные экспериментальные штаммы. Однако такие синтезированные вирусы очень быстро, в течение нескольких циклов размножения, теряют свои свойства.

probegallo |
Дата 2 Апреля, 2005, 21:34
Quote Post


Чего только не нароешь случайно, шарясь по Интернету.


Из интервью начальника Вирусологического центра НИИ микробиологии МО РФ:

В настоящее время существует достаточное количество примеров вредного воздействия трансгенных продуктов. Например, экспериментально установлено, что внедренный в практику сельского хозяйства ряда стран трансгенный картофель, устойчивый к действию колорадского жука, при использовании в качестве корма вызывает у животных угнетение иммунной системы, необратимые изменения репродуктивных органов и уменьшение объема головного мозга (County A., Down R. E., Gatehouse A. M., Kaiser L., Pham-Delegue M., Poppy G. M. Effects of artificial diet containing GNA-expressing potatoes on the development of the aphid parasitoid Aphidius ervi Haliday (Hymenoptera: Aphidiidae). J Insect Physiol. 2001 Dec.; 47(12): 1357-1366. http;//psb.ad-sbras.nsc.ru/kartofw.htm).
probegallo |
Дата 2 Апреля, 2005, 22:00
Quote Post


Вообще, интервью весьма занимательное:

"...когда мы передали ВОЗ 100 доз нашего иммуноглобулина против лихорадки Эбола, то в дальнейшем, по нашей информации, этот препарат попал не в Африку, где ежегодно фиксируются сотни случаев этого абсолютно смертельного заболевания, а в Форт-Детрик - институт инфекционных заболеваний армии США. Негативных публикаций в научной прессе тоже не было, хотя американцы не преминули бы это сделать, если бы доказали, что наш препарат чем-то не хорош.

- Отмечает ли Родина работу военных микробиологов боевыми наградами?

- Широкий общественный резонанс имело создание единственного в мире иммуноглобулина для профилактики лихорадки Эбола. За эту работу бывший начальник Вирусологического центра генерал-майор медицинской службы Александр Махлай был удостоен в 1995 году звания Героя России. А летом 1999 года нашим специалистам снова пришлось расшифровывать истинную природу неизвестной инфекции, вспыхнувшей в станице Обливской Ростовской области и в Ставропольском крае - никто из гражданских врачей не мог поставить точный диагноз, зато возникло предположение насчет распространения лихорадки Эбола среди местного населения. Не исключалась даже возможность введения карантина в Ростове-на-Дону, что привело бы к полному перекрытию транспортных потоков на Северный Кавказ и обратно и к организации массы санпропускников, пунктов питания - в общем, огромным финансовым затратам для страны. И только бригада наших специалистов, срочно прилетевшая в Старый Оскол (для этого у нас есть своя эскадрилья в войсках РХБЗ), провела необходимые диагностические исследования и в течение суток установила, что это не лихорадка Эбола, а Конго-Крымская геморрагическая лихорадка, возбудители которой не так опасны при передаче от человека к человеку. Все сразу облегченно вздохнули, нужда в карантине отпала, хотя наши специалисты были готовы на неподготовленной базе и при минимальных средствах защиты не только оказать помощь выявленным контактным лицам (прилетели с определенным запасом иммуноглобулина), но и локализовать очаг заражения."
probegallo |
Дата 12 Апреля, 2005, 1:41
Quote Post


Снова о маленьком пушЫстом северном зверьке:


1000's of Children in Ho Chi Minh City with Bird Flu Symptoms

Recombinomics Commentary
April 11, 2005

>>Hospitals in Ho Chi Minh City have been filled with thousands of children who have caught respiratory and digestive illnesses due to the hot weather.

Pediatric Hospital I reported that it had examined nearly 4,000 children patients a day with some 85 per cent of them suffering from respiratory problems, said a hospital doctor.

Meanwhile, more than 3,000 children were brought into Pediatric Hospital II on Monday. One-third of the children had respiratory problems and 300 others had digestive problems.

Besides, many children have been hospitalized for brain diseases caused by the entero virus.

The major reason behind the illnesses is that children are sleeping all night with fans on due to the hot weather in recent days.<<

The deafening dearth of data in Vietnam may have ended.

The number of children alone would be cause for concern, but large numbers of patients with respiratory and digestive illness and "brain diseases". in Vietnam ring alarm bells very loudly.

Serious H5N1 testing is indicated, although results from Quang Binh, Haiphong, and Quang Ninh have not been reported.

Bird flu monitoring in Vietnam is well beyond scandalous.

Добавлено в 01:43
рекомендую посмотреть
probegallo |
Дата 23 Апреля, 2005, 17:22
Quote Post


Bird flu looking more like a pandemic


Hanoi, Vietnam, Apr. 23 (UPI) -- Public health officials in Vietnam fear the South Asian outbreak of bird flu is becoming less virulent and, thus, more likely to spawn a pandemic.

The new fear stems, ironically, from the declining mortality rates of infected humans, the Washington Post reported Saturday.

About a year ago some two-thirds of human victims in Vietnam died, but recently that figure has plunged by nearly half.

If that trend continues, it raises the likelihood that infected humans' greater longevity will result in more people contracting avian influenza -- and thus increasing the chances it will become a global problem.

"The virus could be adapting to humans," said Peter Horby, an epidemiologist with the World Health Organization in Hanoi, the Vietnamese capital. "There's a number of indications it could be moving toward a more dangerous virus."

By way of comparison, the 1918 Spanish flu pandemic that killed some 40 million people worldwide, had a 5 percent mortality rate. The comparable rate for bird flu has fallen from nearly 70 percent to 35 percent this year.

Also worrying health officials is the emergence of asymptomatic bird flu in poultry
Добавлено в [mergetime]1114262697[/mergetime]
Dark side to good news on bird flu

As virus becomes less lethal, it could gain mobility

By Alan Sipress
The Washington Post
Updated: 11:16 p.m. ET April 22, 2005

HANOI - Nguyen Sy Tuan can barely talk. His wasted frame is tucked beneath a thin white sheet on the hospital cot. His cheeks are sunken and his bulging eyes stare blankly at the ceiling. But the young man has begun to eat rice again and can finally breathe without a mechanical ventilator, a dramatic turnaround for a bird flu patient whose doctors had assumed would die.

More than a year after avian influenza emerged in East Asia, killing more than two-thirds of the people with confirmed cases, Vietnamese doctors are reporting that the mortality rate in their country has dropped substantially.

An ominous turn
But while this is good news for survivors, it could mean the outbreak of bird flu in Southeast Asia is taking an ominous turn. If a disease quickly kills almost everyone it infects, it has little chance of spreading very far, according to international health experts. The less lethal bird flu becomes, they say, the more likely it is to develop into the global pandemic they fear, potentially killing tens of millions of people.

"The virus could be adapting to humans," said Peter Horby, an epidemiologist with the World Health Organization in Hanoi, the Vietnamese capital. "There's a number of indications it could be moving toward a more dangerous virus."

The mortality rate for bird flu in Vietnam this year is about 35 percent, almost exactly half that of last year, according to Health Ministry statistics. The mortality rate of the 1918 Spanish flu pandemic, by comparison, was less than 5 percent, but the outbreak killed an estimated 40 million people worldwide.

Officials said the drop in the bird flu mortality rate was more marked in northern Vietnam than in the south. While the virus in southern Vietnam is still killing at the same pace as last year, the rate in the area around Hanoi and elsewhere in the north has dropped from that level to as low as 20 percent. Vietnamese health experts said their suspicion that the disease is shifting is further supported by preliminary research showing a genetic change in the virus in the north resulting in the production of a protein with one fewer amino acids than in the south.

A virus on the move?
Health researchers believe that nearly all the 52 people known to have died of bird flu in Southeast Asia caught the virus from infected poultry. But with more clusters of cases among families reported in Vietnam this year — including that of Tuan, his sister and their grandfather — experts say they are growing increasingly suspicious that the disease has begun passing from one human to another.

Also worrying is the discovery of at least five cases, including that of Tuan's grandfather, in which people tested positive for bird flu but showed no symptoms. This could make it more difficult to contain an epidemic because people could transmit the disease without anyone realizing it.

Last year, U.S. researchers reported that ducks in Southeast Asia had begun carrying the bird flu virus without showing symptoms. Now, scientists in Vietnam have found numerous asymptomatic cases in the country's vast chicken population, according to Nguyen Tran Hien, director of the National Institute of Hygiene and Epidemiology.

"It seems that the virus may adapt in humans and in poultry a little bit. Therefore, the symptoms are not as severe as before," Hien said. "Also, the transmission may be faster and easier."

Moreover, the existing virus strain is not the only threat. Each human case also presents a chance for the bird flu virus to swap genetic material with an ordinary flu bug — if the person becomes infected with both strains at the same time — potentially creating a new hybrid that is highly lethal and even easier to catch.

"We are concerned that if the virus is changing, maybe a new virus is coming in the future," Hien said.

Two survivors
Tuan, 21, left his home among the glistening paddies of northern Vietnam's rice-growing region more than a year ago for Haiphong, on the coast, where he worked harvesting seaweed for use in local cuisine. In early February, he returned to his family's simple brick house to celebrate the Tet New Year holiday.

According to his doctors, Tuan slaughtered a chicken for a festival meal, cutting its neck while his 14-year-old sister clutched the wings and legs. The bird was likely infected, and soon the siblings were, too.

Tuan started running a high fever about four days later, his wizened father recounted between puffs on a traditional bowl pipe in the family's one-room home.

When Tuan started coughing and had trouble breathing, he was taken to the local health center in Thai Thuy district. X-rays showed a white smudge on his left lung. Tuan was transferred after less than a day to a larger hospital in the provincial capital. There, the doctors concluded he had contracted the H5N1 strain of avian influenza and immediately rushed him to the tropical disease institute at Hanoi's Bach Mai Hospital.

By the time he arrived, X-rays showed, the white smudge had clouded the entire lung. Soon it took over the other one as well. "From one day to the next day, it spread very quickly," recalled Nguyen Thi Tuong Van, deputy director of the Bach Mai intensive care unit.

After 10 days, with his breathing failing, the doctors inserted a tube in Tuan's throat and put him on a ventilator. The infection spread to his kidneys and liver.

"We thought it was very likely the bird flu would kill him," Van said. "Then, when it seemed the situation couldn't get much worse, it started to get better. Two weeks later, when he didn't die, I thought maybe we could cure him."

Tuan's sister, Nguyen Thi Ngoan, a tall, mischievous 14-year-old with large black eyes, fell sick several days after her brother and also recovered.

At the district health center, X-rays revealed her lungs were clear, but a subsequent blood test was positive for bird flu. She was transferred to the Hanoi hospital, where she lay in the cot beside her brother and her temperature soared to 105 degrees.

But the fever broke after four days and returned to normal within two weeks, her doctors said. Ngoan went back to school in late March as a local celebrity, teased by her peers as "Miss H5."

A vital question
Vietnamese and international health officials say they are confident that the mortality rate has dropped but are not sure by how much. Better screening and wider public awareness of bird flu could mean health workers are catching and recovering from milder cases that would have gone unreported a year ago. WHO officials have complained, however, that Vietnam is reluctant to provide detailed information about human cases. Senior Health Ministry officials respond that reports are provided in accord with national regulations.

The question now is whether bird flu in Vietnam has begun passing among humans.

If it has, Nguyen Duc Tinh, a nurse who treated Tuan at the Thai Thuy district health center and fell sick with bird flu soon after, would be a likely instance. Tinh, 26, said he had no contact with poultry for a month beforehand despite government accounts attributing his illness to infected chickens.

Tinh said he was the hospital staff member who had the closest contact with Tuan during his brief stay at the health center, taking his blood pressure and temperature, giving him injections and helping him walk. Within a week, Tinh had developed muscle aches and a high fever, symptoms of what he believed was a common flu. But when the fever subsided and then returned two days later, he grew alarmed.

"Then I suspected I had bird flu," he recalled, his brown eyes widening. "I was really, really afraid of dying."

But just two weeks after joining Tuan in the Hanoi hospital, Tinh was discharged and went back to his village.

"I had lost hope when the fever came a second time," he said. "When I returned to my home town, I felt as if I were born again."

© 2005 The Washington Post Company
© 2005 MSNBC.com

URL: http://www.msnbc.msn.com/id/7593132/
LandWarrior |
Дата 25 Апреля, 2005, 18:27
Quote Post


Интересная ссылка:
Rumata | Профиль
Дата 25 Апреля, 2005, 19:02
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The One
Group Icon

Группа: Admin
Сообщений: немеряно
Регистрация: 21.06.03

Вне форума

да да да, форум не дает возможности постить ссылки если менее 10 постов.

Ничто так не сближает людей, как снайперский прицел
probegallo |
Дата 10 Май, 2005, 7:20
Quote Post


кстати, напоминаю ссылку, где публикуются свежие новости по проблеме и их профессиональное обсуждение - http://discuss.agonist.org/yabbse/index.php?board=6

probegallo |
Дата 10 Май, 2005, 14:41
Quote Post


10 мая, 09:14

Феодосии угрожает «птичий грипп»?

Последние три недели в Феодосийскую ветлечебницу общества защиты животных горожане приносят больных голубей с одинаковыми симптомами: нарушение координации и глотания.

По словам ветеринара Елены Филипповой, эти симптомы очень похожи на проявление энцефалопатии - отека головного мозга. Некоторые болезни передаются человеку от птиц, но в этом случае людям вряд ли что-то угрожает.

«Все голуби, которых мне приносили, умирали. Недавно ко мне пришел молодой человек, который принес голубя с теми же симптомами. Сейчас он сам смотрит за птицей, пытается ее вылечить. Теща этого парня - патологоанатом, если голубь умрет, она сможет провести вскрытие, и мне сообщат о результатах», - рассказала Елена Филиппова, передает «Обком».

Филиппова также сообщила, что многие болезни передаются человеку от птиц, особенно от голубей. Но голуби ее не заразили, поэтому Елена Владимировна считает, что болезнь для человека не опасна.

По словам заведующей инфекционным отделением феодосийской городской больницы №1 Лидии Демешиной, есть такое заболевание «орнитоз», которое передается человеку от птиц, в основном голубей.

«Проявление клинического орнитоза - пневмония, - сказала она. - Я не думаю, что сейчас голуби болеют именно этой инфекцией. За 19 лет моей работы в Феодосии, я ни разу не сталкивалась с подобными случаями».

probegallo |
Дата 18 Май, 2005, 11:30
Quote Post



Tamiflu Resistant H5N1 in Vietnam?

Recombinomics Commentary
May 17, 2005

>> The genetic changes they have seen in the northern Vietnam viruses are in the gene that codes for the spike, a molecule called haemaglutinin, in a part that controls how well the spike fits into the receptor…….

One final surprise too. One recent sample from Vietnam proved to be, in part, resistant to the drug mainly used to treat victims of H5N1.

Chances are it's a one-off - the patient was being treated with the drug - but the WHO scientists warn that if further samples are found, it would have serious implications indeed. <<

The above comments on changes in HA suggest that the protein that is missing one amino acid is HA, and the missing amino acid is in the poly-basic cleavage site. If so, it is likely that the missing amino acid matches the missing amino acid in H5N1 found in Shanghai and other provinces in eastern China. These data suggest that the new H5N1 in northern Vietnam is indeed a recombinant between the H5N1 in Vietnam and the H5N1 in China.

The data also suggests that H5N1 in China is being under-reported, adding to the misinformation provided by the poor surveillance of H5N1. China, like all Asian countries that had H5N1 last year or this year, has not submitted any publicly available 2005 H5N1 sequences to GenBank. The sequences held by WHO consultants, but not shared with the rest of the scientific community, may indeed provide clues that WHO appears to have trouble interpreting beyond a funny noise in a car.

Thus, media reports suggest that significant changes are occurring in HA and NA. NA is targeted by the only available H5N1 antiviral, Tamiflu. The above report suggests that an H5N1 Tamiflu-resistant strain has evolved. Widespread use of Tamiflu will generate selection pressure for resistance. The comments above imply that such resistance is relatively easy for H5N1, since the number of H5N1 confirmed patients treated with Tamiflu has been exceedingly low. Tamiflu is the antiviral drug being stockpiled by many countries.

However, because surveillance of H5N1 in mild cases in northern Vietnam has been virtually absent, the possibility of Tamiflu treatment of mild human cases is quite real, since the drug has been approved for treatment and prevention of influenza. Widespread treatment with Tamiflu will likely generate widespread resistance.


Добавлено в 11:32
Bird flu 'may pass to humans'

Published: 17 May 2005

By: Julian Rush

Scientists are warning that the virus which causes bird flu could soon be able to pass between humans.

New evidence seen by Channel 4 News points to an increased risk of a global flu outbreak because of the way the virus has started to mutate.

It has killed 52 people in Asia in the last two years, and despite the slaughter of millions of birds has not stopped spreading. Now we've seen a report by World Health Organisation scientists which warns that the risk of a global flu outbreak is increasing.

These are the first signs the bird flu virus H5N1 is evolving and evolving in ways that make a global pandemic more likely.

Deep in northern Vietnam, scientists have noticed localised changes in the patterns of infection.

In the lab, they have seen genetic changes too that suggest the virus in northern Vietnam is different: changes that may affect how the disease will spread.

Scientists at the World Health Organisation monitoring avian flu in South East Asia say they are seeing what they call a "worrisome development".

Recent cases have started appearing in clusters and the disease is getting a little milder - signs, they say, the virus may be adapting to humans: changing genetically to transmit more easily between people at the cost of losing a little of its virulence.

Professor Maria Zambon from the Health Protection Agency, told Channel 4 News: If you have a virus which is more virulent for humans it may be less transmissable. But if the virus is better able to transmit within humans it may be less virulent.

Even a weakened H5N1 virus will still be very dangerous. A flu virus infects human cells when a protein spike on the virus binds with a receptor on the cell surface.

The genetic changes they have seen in the northern Vietnam viruses are in the gene that codes for the spike, a molecule called haemaglutinin, in a part that controls how well the spike fits into the receptor.

The report we've seen recommends immediate steps should be taken to step up surveillance in countries where H5N1 is present and they say there's an urgent need for up-to-date information on the genetics of the virus.

Constant monitoring of virus from new victims is the key: the WHO denies reports south-east Asian countries have failed to provide samples - Vietnam alone has supplied over a hundred - but it does admit it's been hard to extract virus from many of them, hampering research.

H5N1 is proving to be a virus full of surprises. The original jump from wild ducks - where it doesn't cause illness - to domestic chickens where it kills - was a genetic leap akin to a jump from a cat to a horse. The leap from chickens to humans was even bigger.

The nastiest surprise would be what's called reassortment - if a completely new virus emerged after H5N1 got into someone already infected with conventional human flu.

So news today three pigs in Indonesia have tested positive for H5N1 is a warning. There aren't many pigs in this largely Muslim country, but as a precaution pigs are being quarantined and tested before they're slaughtered.

And the news there are signs of genetic shifts in the virus in northern Vietnam could affect the plans of some governments to control a pandemic with vaccines.

Many that are now being stockpiled are based on British research that took a virus from Vietnam last year and genetically engineered to make it safe. The man who did it admits genetic shifts since then could make the stockpiles redundant.

One final surprise too. One recent sample from Vietnam proved to be, in part, resistant to the drug mainly used to treat victims of H5N1.

Chances are it's a one-off - the patient was being treated with the drug - but the WHO scientists warn that if further samples are found, it would have serious implications indeed.
probegallo |
Дата 19 Май, 2005, 7:30
Quote Post


WHO report charts disturbing changes in avian flu virus, urges preparations


WHO report charts disturbing changes in avian flu virus, urges preparations

Helen Branswell
Canadian Press

Wednesday, May 18, 2005

TORONTO (CP) - The World Health Organization urged countries to make full haste with pandemic influenza preparations Wednesday as it released a report outlining disturbing changes to the H5N1 virus circulating in Asia.

Among the recent findings is evidence the virus's genetic makeup appears to be altering in a way that may make H5N1 better adapted for spread among people.

As well the report documents a case where the virus showed partial resistance to the main drug the wealthy countries of the world are stockpiling to combat it, oseltamivir.

While experts cautioned that finding is not necessarily surprising, it does raise questions about whether an oseltamivir-resistant strain of the virus could propagate and spread. The report notes that scenario, if it were to occur, would have "significant implications for . . . H5N1 prevention and control."

A leading infectious disease expert said the evidence in the report is limited, but paints a worrisome picture of a changing pattern of infection and disease in northern Vietnam.

"I think it tells us that everything about H5N1 is headed in the direction that none of us would like to see it go," said Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

"Do I say that that's going to mean there's an impending pandemic? I don't know that. Does it tell me that . . . there's a growing concern about it? Absolutely."

Evidence in the report was drawn from a recent WHO fact-finding mission to Vietnam and from a meeting of influenza experts in Manila last week.

The WHO admits the implications of the changes in both disease patterns and viral makeup are not fully clear, but suggests the viruses "pose a continuing and potentially growing pandemic threat."

"Based on these concerns and findings, it would be prudent to . . . implement or complete pandemic preparatory actions as soon as possible, even if current H5N1 outbreaks in Asia cease or diminish during the summer," it states.

In recent weeks flu experts have been sounding the alarm about the changing pattern of infection in northern Vietnam.

This spring there has appeared to be more clusters of cases, possibly the result of more limited human-to-human spread, and a greater age range of cases. As well the case fatality rate has dropped - something experts had anticipated would have to happen if H5N1 were to become a pandemic strain.

The report combines information about those changes with disturbing laboratory findings. Some viruses are showing genetic changes near what's known as the "receptor binding site" - the point where the invading virus attaches to the cell walls of a host.

Flu viruses made entirely of avian influenza genes don't tend to bind well to human receptor binding sites. But these changes may indicate the virus is evolving to be a better fit.

Science is not currently capable of predicting what, if anything, these changes mean, especially with the limited data that has emerged so far, said Dr. Earl Brown, a virologist at the University of Ottawa who specializes in flu evolution.

"It's incomplete science," he said.

More evidence may emerge in coming weeks.

Canada's National Microbiology Laboratory has sent a team of three scientists to Hanoi to help scientists there analyse blood samples from contacts of H5N1 cases. The goal is to try to get a sense how many have developed antibodies to the virus - a sign they were infected, possibly by human-to-human spread.

"It will help a lot in, I think, clarifying the extent of infection," said Dr. Frank Plummer, scientific director of the national lab. The team, led by Dr. Yan Li, chief of the influenza laboratory, left for Hanoi on Wednesday.

WHO: flu pandemic threat may be growing

May 18, 2005 (CIDRAP News) – The H5N1 avian influenza virus is evolving and poses "a continuing and potentially growing pandemic threat," say experts who were convened recently by the World Health Organization (WHO) to study the pathogen.

Changing patterns of cases, particularly in northern Vietnam, may indicate the virus is becoming more infectious for humans, the WHO said in a report on an international meeting of experts held May 6 and 7 in Manila. In addition, genetic analysis indicates that H5N1 viruses are becoming more antigenically diverse.

The report cites several differences between epidemiologic features of human cases this year in northern Vietnam and those in southern Vietnam this year and overall last year:

* Northern Vietnam has had eight case clusters this year, versus only two in the south.
* Case clusters in northern Vietnam this year have lasted longer than did clusters last year.
* The average age of infected people in northern Vietnam rose from 17 to about 31 years between 2004 and 2005, but it stayed about the same in southern Vietnam (15 to 18 years).
* The case-fatality rate has dropped to 34% this year in the north but is 83% in the south.

In addition, the report says the recent discovery of three asymptomatic cases in Vietnam suggests that milder infections are occurring. A few asymptomatic cases also were found in Japan and Thailand in the past year, and others were discovered in Hong Kong after the H5N1 outbreak in 1997.

The report says the longer duration of recent clusters may signal a growing number of ways in which people contract the virus, including exposure to sick birds, environmental infection, lengthy exposure to asymptomatic birds that are shedding virus, and person-to-person transmission.

The avian virus had already vaulted to the top of the pandemic threat list because it had developed the ability to sicken and kill humans. The virus's inability to cause efficient, ongoing human-to-human transmission is the last barrier to a pandemic. Now experts appear worried that the barrier is crumbling.

"Investigators were not able to prove that human-to-human transmission had occurred. However, they expressed concerns, which were shared by local clinicians, that the pattern of disease appeared to have changed in a manner consistent with this possibility," the assessment states.

At the same time, it says that in places where the disease in poultry has been controlled or eliminated, human cases have stopped. And thus far, the first case in most of the human clusters in Vietnam followed the person's exposure to infected poultry.

For now, "Prevention of H5N1 avian influenza in humans is best achieved by controlling infection in poultry," the document states. "As already recommended by FAO and OIE [the United Nations Food and Agriculture Organization and the World Organization for Animal Health], control strategies for this disease should consider vaccination of poultry, which has been used successfully before."

A team of WHO expert consultants studied Vietnam's outbreak at that country's request from Apr 15 through 25, the report says. That study showed H5N1 could be changing more in the northern region, which prompted a second expert consultation.

This second meeting was held May 6 and 7 at the WHO regional office in Manila. Representatives from Vietnam, Cambodia, and Thailand presented details about the epidemiologic, clinical, and virologic findings regarding H5N1 in people and poultry. Other data were included from the WHO Global Influenza Network and other countries.

The experts make a number of recommendations, including increasing efforts to improve risk assessment, to boost the ability of affected countries to address outbreaks, and to speed the pace of pandemic planning.

The 14 recommendations include the following:

* WHO should convene its Pandemic Task Force to meet regularly, assess the data, and determine the risk for pandemic flu.
* All nations should move as quickly as possible to complete "practical operational pandemic preparedness plans."
* WHO should explore "all possible mechanisms" to make H5N1 vaccine available to the Asian countries affected before a pandemic. It should bring together technical experts, countries, manufacturers and possible donors to find ways to boost global H5N1 vaccine production.
* Coordination of animal and human surveillance and viral information must be improved from the ground level to the national and international level, and data must be exchanged quickly.
* The WHO should complete a handbook on how to investigate possible H5N1 clusters.
* The WHO should explore building a stockpile of antiviral drugs that could be used to respond to early signs of a potential pandemic.
* Countries needing funding and agencies that may provide funding must coordinate their efforts to avoid redundancy and eliminate gaps

As the experts call for greater international effort to address the escalating threat, they also acknowledge the difficulties of preparing for a possible pandemic:

"Evolution of a pandemic strain of virus may be preceded by numerous small steps, none of which is sufficient to signal clearly that a pandemic is about to start. This poses a difficult public health dilemma. If public health authorities move too soon, then unnecessary and costly actions may be taken. However, if action is delayed until there is unmistakable evidence that the virus has become sufficiently transmissible among people to allow a pandemic to develop, then it most likely will be too late to implement effective . . . responses."

probegallo |
Дата 20 Май, 2005, 7:22
Quote Post


ВОЗ: Птичий грипп может передаваться от человека к человеку

19 Мая 2005, 16:04

Последние исследования подтвердили возможность передачи вируса птичьего гриппа от человека к человеку. Об этом в четверг, 19 мая, в Женеве, Швейцария, объявила Всемирная организация здравоохранения (ВОЗ).

Ранее эксперты уже выражались обеспокоенность по поводу возможной мутации вируса птичьего гриппа, из-за чего он в ближайшем будущем будет легко передаваться от человека к человеку, что неминуемо обернется миллионами жертв.

До последнего времени считалось, что смертельно опасный вирус не передается подобным образом, однако последние исследования, проведенные во Вьетнаме, доказали обратное, заявила сегодня ВОЗ.

Эксперты организации уже выразили опасения по поводу возможной пандемии птичьего гриппа.

"Мы считаем, что будет пандемия, но не знаем когда", - заявил в четверг глава отдела по надзору за инфекционными заболеваниями ВОЗ Геналь Родье.

С конца 2003 года опасный для человека штамм вируса птичьего гриппа H5N1 уже унес жизни более 50 человек в Юго-Восточной Азии. Наибольшее количество погибших зарегистрировано во Вьетнаме – 37. Кроме того, 12 человек погибли в Таиланде и 4 – в Камбодже.

По материалам Associated Press

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