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发帖数: 40861 | 1 【 以下文字转载自 WaterWorld 讨论区 】
发信人: deer2005 (老鹿), 信区: WaterWorld
标 题: 依博拉病（Ebola virus disease）：真相和热点
发信站: BBS 未名空间站 (Sat Oct 4 13:08:03 2014, 美东)
依博拉病（Ebola virus disease）：真相和热点
博客文章：
http://www.mitbbs.com/pc/pccon.php?id=14439&nid=338895
几天来，由于在德州Dalas发现美国国内首例病例，Ebola成了人们谈论的热点话题，
Ebola相关生化药股也在爆涨中。
Ebola可怕么？它如何传播？如何预防和治疗Ebola？
这里讨论了一些关于Ebola的热点问题：
（一）Ebola的真相
世界卫生组织（WHO）列举的关于Ebola的关键事实：
1. Ebola virus disease (EVD), formerly known as Ebola haemorrhagic
fever, is a severe, often fatal illness in humans.
2. The virus is transmitted to people from wild animals and
spreads in the human population through human-to-human
transmission.
3. The average EVD case fatality rate is around 50%. Case fatality
rates have varied from 25% to 90% in past outbreaks.
4. The first EVD outbreaks occurred in remote villages in Central
Africa, near tropical rainforests, but the most recent outbreak in
west Africa has involved major urban as well as rural areas.
5. Community engagement is key to successfully controlling
outbreaks. Good outbreak control relies on applying a package of
interventions, namely case management, surveillance and contact
tracing, a good laboratory service, safe burials and social
mobilisation.
6. Early supportive care with rehydration, symptomatic treatment
improves survival. There is as yet no licensed treatment proven to
neutralise the virus but a range of blood, immunological and drug
therapies are under development.
7.There are currently no licensed Ebola vaccines but 2 potential
candidates are undergoing evaluation.
要点： Ebola是一种烈性传染病，死亡率很高，但可防可控。
（二）Ebola的传播途径
美国疾病控制中心（CDC）阐述的关于Ebola传播途径，比较清晰：
When an infection does occur in humans, the virus can be spread in
several ways to others. Ebola is spread through direct contact
(through broken skin or mucous membranes in, for example, the
eyes, nose, or mouth) with：
1. blood or body fluids (including but not limited to urine,
saliva, sweat, feces, vomit, breast milk, and semen) of a person
who is sick with Ebola
2. objects (like needles and syringes) that have been contaminated
with the virus
3. infected animals
Ebola is not spread through the air or by water, or in general, by
food.
However, in Africa, Ebola may be spread as a result of handling
bushmeat (wild animals hunted for food) and contact with infected
bats. There is no evidence that mosquitos or other insects can
transmit Ebola virus. Only mammals (for example, humans, bats,
monkeys, and apes) have shown the ability to become infected with
and spread Ebola virus.
要点：Ebola通过接触传播，不通过空气与饮食传播。
（三）抗艾滋病药能否治愈Ebola？
While experts and health authorities around the world are baffled
with the task of controlling the Ebola outbreak without the
availability of a licensed Ebola treatment, a Liberian doctor has
taken matters into his own hands. Gorbee Logan, working in rural
Liberia, administered human immunodeficiency virus (HIV) drug
lamivudine to 15 Ebola patients, and surprisingly 13 of them
recovered despite the virus having a mortality rate of 70%.
This has led the National Institutes of Health (NIH) to also
explore the potential of the drug, which is marketed as Epivir by
GlaxoSmithKline plc (ADR) (GSK) for the treatment of Hepatitis B.
Liberia is one of the hardest Ebola-hit countries in Africa. Due
to the lack of Ebola drugs and the poor conditions of health
facilities, Logan has had to resort to unorthodox methods to treat
his patients. He defended his actions in an interview with CNN by
saying that, while authorities are struggling with getting through
trials and studies, the only option doctors are left with is to
utilize other approved drugs.
Logan believes that the Ebola virus is a destructive strain of the
same virus that causes the fatal liver disease HIV. He claims that
the two patients who died were given the drug after five days of
developing Ebola symptoms, compared to others who took the drug
earlier.
After the interview, the NIH took notice of Logan’s findings and
has now started testing if lamivudine can help Ebola patients.
Director of NIH’s National Institute of Allergy and Infectious
Diseases (NIAID), Dr. Anthony Fauci, has said that while the
merits of Logan’s actions are debatable, the situation is such
that any available therapies can be explored.
Fauci, who is an immunologist and has done considerable research
on HIV, also added that using lamivudine makes sense as it works
by inhibiting the replication of certain viruses. However, the
Ebola virus did not respond to the drug in a test tube study.
Fauci plans to continue testing with adjusted levels of the drug.
Clinical trials for lamivudine as an anti-Ebola treatment will be
conducted if positive results are achieved.
There are ethical dilemmas of using a drug that has not been
approved for the indication of Ebola. However, Logan argues that
while the drug may have serious side-effects, patients will die
without some sort of treatment. He added that the urgency of the
matter calls for taking risks.
Another question that remains unanswered is whether the drug will
be used as a treatment option for Thomas Duncan, the first patient
to be diagnosed with Ebola in the US. Duncan is currently admitted
in a hospital in Dallas.
Meanwhile, GSK is working on an Ebola vaccine, human trials for
which have started in the UK and US. Another leading candidate is
Tekmira Pharmaceuticals Corporation’s (TKMR) TKM-Ebola, which the
US Food and Drug Administration (FDA) recently approved for
emergency use.
要点：Lamivudine似乎可以治疗Ebola，但没有实验室依据证实。希望抗艾药物真能
治愈Ebola。
（四）Ebola的预防和治疗
预防：
There is no FDA-approved vaccine available for Ebola.
If you travel to or are in an area affected by an Ebola outbreak,
make sure to do the following:
1. Practice careful hygiene. For example, wash your hands with
soap and water or an alcohol-based hand sanitizer and avoid
contact with blood and body fluids.
2. Do not handle items that may have come in contact with an
infected person’s blood or body fluids (such as clothes, bedding,
needles, and medical equipment).
3. Avoid funeral or burial rituals that require handling the body
of someone who has died from Ebola.
4. Avoid contact with bats and nonhuman primates or blood, fluids,
and raw meat prepared from these animals.
5. Avoid hospitals where Ebola patients are being treated. The
U.S. embassy or consulate is often able to provide advice on
facilities.
6. After you return, monitor your health for 21 days and seek
medical care immediately if you develop symptoms of Ebola.
治疗：
No FDA-approved vaccine or medicine (e.g., antiviral drug) is
available for Ebola.
Symptoms of Ebola are treated as they appear. The following basic
interventions, when used early, can significantly improve the
chances of survival:
1. Providing intravenous fluids (IV)and balancing electrolytes
(body salts)
2. Maintaining oxygen status and blood pressure
Treating other infections if they occur
3. Experimental vaccines and treatments for Ebola are under
development, but they have not yet been fully tested for safety or
effectiveness.
Recovery from Ebola depends on good supportive care and the
patient’s immune response. People who recover from Ebola infection
develop antibodies that last for at least 10 years, possibly
longer. It isn't known if people who recover are immune for life
or if they can become infected with a different species of Ebola.
Some people who have recovered from Ebola have developed long-term
complications, such as joint and vision problems.
要点：Ebola的预防和控制尚没有特异性方法，但流行病学预防措施是有效可行的。
（五）Ebola疫苗：两个领先者
1、TKM-Ebola
TKM-Ebola is an experimental drug for Ebola disease.
TKM-Ebola is being developed by Tekmira Pharmaceuticals Corp., a
company located in Vancouver, Canada.The drug was formerly known
as Ebola-SNALP.
It is a combination of Small interfering RNAs targeting three of
the seven proteins in Ebola virus: Zaire Ebola L polymerase, Zaire
Ebola membrane-associated protein (VP24), and Zaire Ebola
polymerase complex protein (VP35), formulated with Tekmira's lipid
nanoparticle technology.
In January 2014, Tekmira commenced a Phase I clinical trial of
TKM-Ebola to assess its safety in healthy people. The FDA put the
trial on clinical hold in July 2014 to assess results, after some
subjects had flu-like responses. In August, the FDA changed the
status to "partial hold", allowing the drug to be used under
Expanded access in people infected with Ebola but with the Phase I
trial still suspended.
2、ZMapp
ZMapp is an experimental biopharmaceutical drug comprising three
humanized monoclonal antibodies under development as a treatment
for Ebola virus disease. The drug was first tested in humans
during the 2014 West Africa Ebola virus outbreak and was credited
as helping save lives, but it has not been subjected to a
randomized clinical trial to prove its safety or its efficacy.
Like intravenous immunoglobulin therapy, ZMapp contains
neutralizing antibodies that provide passive immunity to the virus
by directly and specifically reacting with it in a "lock and key"
fashion.
The ZMapp drug is being developed by Mapp (Leaf) Biopharmaceutical
Inc., based in San Diego.ZMapp is composed of three monoclonal
antibodies (mAbs) that have been humanized by genetic engineering.
The components are humanized monoclonal antibody c13C6 from a
previously-existing antibody cocktail called "MB-003" and two
humanized mAbs from a different antibody cocktail called "ZMab",
c2G4 and c4G7.
要点：Ebola疫苗研究有些进展，但要走的路依旧很长。 | s******r
发帖数: 88 | 2 疫苗和一般的药物不是一回事。疫苗是在人体内注入病原体本身的分子结构来诱发身体
的免疫反应。Zmapp肯定不是疫苗，TKM-Ebola听上去也不是。 | s********n
发帖数: 2939 | 3 Zmapp是混合抗体，直接省略了抗原免疫这一步
【在 s******r 的大作中提到】
: 疫苗和一般的药物不是一回事。疫苗是在人体内注入病原体本身的分子结构来诱发身体
: 的免疫反应。Zmapp肯定不是疫苗，TKM-Ebola听上去也不是。
| d****o
发帖数: 32610 | 4 zmapp是混合单抗，TKM-Ebola纯粹是药，只不过成分是RNA
【在 s******r 的大作中提到】
: 疫苗和一般的药物不是一回事。疫苗是在人体内注入病原体本身的分子结构来诱发身体
: 的免疫反应。Zmapp肯定不是疫苗，TKM-Ebola听上去也不是。
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