Posted on 05/31/2005 12:09:14 PM PDT by Judith Anne
This is the Marburg Surveillance Project Thread II.
This thread, as the first one was, will be used for all of the latest Marburg Outbreak News and comments. This is the place to post all comments about the Marburg outbreak, all articles and links to articles about the Marburg outbreak.
I wish I could answer your question. But I did not make the model, I just tried to bring it over from the other thread. Please refer your queston to 2ndreconmarine as he is the author and would gladly give you an answer......
Good question. I hope Dr. Ip checks in soon, perhaps he would have some insight.
Has he still not shown up at work?
There is a common mention of caves or mine workings, and bushmeat as potential reservoirs/sources for the virus.
Speculating wildly, knowing there is at least one species of migrating bat in neighboring Zambia, what is the chance that bats are the delivery mechanism?
The virus, secreted in guano, might be picked up by monkeys in fair weather when the bats are roosting in trees, and in foul weather by humans from the guano when the bats seek better shelter in caves, mine workings, or huts.
Episodes of higher than usual rainfall might not be washing the virus out, but driving the bats in where humans would contact the guano.
If that is the case, the bats which (may) harbor the disease may also have some immune factor which could be identified and put to work to aid humans.
I had previously speculated that there might be a fungus, on the order of agents which cause histoplasmosis, but suppose the guano contains active virii?
How long would these be expected to remain viable pathogens?
This might account for the on again, off again nature of the virus, as well as the localized distribution over a realtively large region.
If migraton patterns are well-defined, then it should be a matter of matching the bats' route and approximate location (seasonally) in the migration pattern with the outbreaks.
Whether the bats, if they are the vector eventually, succumb to the virus would be difficult to ascertain.
Is there any indication whether other predators/scavengers besides humans catch the virus? Or any other animals besides primates?
Hi,
Can't answer your question, but I do remember a report on thread1 that said in a previous outbreak, in the Congo, that they gave blood transfusions from a survivor to some people still ill and if I remember correctly all but one recovered. I have no idea if this strain is close enough to use survivors from the past, or if they need survivors of this particular strain...but it has been documented somewhere in our discussion. They have claimed a number of recoveries, maybe ole Horacio could help, he certainly made a speedy recovery!!
Hi,
Bats are often mentioned, however Dr. Pierre Formnty of the WHO said bats did not seem to be involved in this outbreak.
Proffesor Duse who recently returned from Uige claimed to have seen dogs and pigs dying from marburg.
Also I posted an article on thread1 stating birds could also be carriers of ebola, which is identical to marburg, except it doesn't cause the creation of the same antibodies.
These are all documented somewhere in our discussion.
Either could camp out in caves or mine workings which seem to be mentioned often in outbreaks of ebola or Marburg. more on one type of bat, considered a delicacy
Could there be differences between avian (more reptillian than mammalian) DNA/RNA which would provide inherent resistance for birds as opposed to mammals?
I agree with Judith regarding the containment issue, I feel its probably too late. This has been known since Oct. 2004, and may have started even earlier. At any rate we know it has been festering and spreading since Oct. and I'm sure it has moved around by now. I believe the unfortunate way the Angolans live, in unsanitary conditions has hastened its delivery through man and beast alike...
As for weaponization, I'm stumped. It looks like a weapon because of its deadliness and ease of transmission, however I cannot figure out a reason anyone would want to use it against these poor, long-suffering people... that doesn't make sense to me. But I am naive, sometimes thinking everyone is basically good, and as redgolum pointed out to me...that ain't always so! So my thought is, it seems like a weapon but ... WHY Angola?
Good question! I don't know if birds die from it or not ... another article talked of avian retroviruses recombining with marburg in birds because they have similar RNA (the viruses), since the avian flu kills birds, marburg might kill them also
... perhaps carrier was the wrong term for I am unsure if they are not also victims.
There were Cuban Special Forces present in Angola in the late 20th century, and commonly, satelite nation special forces were accompanied by Soviet 'advisors'.
If the Soviets had a bioagent research facility in Angola, (and the Soviets were known to be working on weaponized versions of ebola/Marburg), they may have simply done a shoddy job of shutting down the facility and disposing of unwanted specimens, cultures, or wastes.
A mere 20 years and some scrounging locals may have liberated such a strain, with the result that it entered the population. (Keep in mind that the average city dumpster in America would contain tremendous wealth for many of these people--many are that poor.).
Although the initial known cases are children in this outbreak, the needles there are re-used after being dipped in hot water.
It is remotely possible that the initial case which led to the infection of the children came in for treatment, got an injection, and left, only to die elsewhere, while the virus was accidentally administered to the children.
There need be no malice involved here beyond development, if this is a weaponized variant, just coincidences with a tragic outcome.
While this is an unlikely scenario, I would not completely rule out this or something similar.
The possibility exists, however, that suicide 'biobombers' could be intentionally infected (weaponized strain or not, it is far more deadly than other variants) in order to attempt to carry the virus elsewhere, which could be a real horrorshow.
RE: past survivors having antibody that could help in these cases - this has been used in past outbreaks. Don't know how long antibody lasts in recovered patients and don't know if it would help in these cases if the virus is truly so different.
I remember Parvo, it wiped out my fathers hog farming operation. It was scary how fast they went down.
_________________________________________
Ebola and Marburg Viruses—Perspective 2005 Speakers:
Christopher Basler, Mount Sinai School of Medicine;
Daniel Bausch, Tulane University School of Medicine;
and Thomas Geisbert, United States Army Medical Research Institute of Infectious Diseases
Sponsored by: Emerging Infectious Diseases Discussion Group
The Emerging Infectious Diseases Discussion Group holds periodic meetings focused on the most recent findings from laboratories in the New York area interested in the field, thus providing an opportunity for not only sharing information and ideas but also for developing and strengthening cooperation among scientists in the area.
Program
5:00–7:30: Presentations
Christopher Basler, Mount Sinai School of Medicine, "Antagonism of the Host Interferon Response by Ebola Viruses."
Daniel Bausch, Tulane University School of Medicine, "Controlling Marburg and Ebola Hemorrhagic Fevers: Where We’ve Been and Where We Need to Go."
Thomas Geisbert, United States Army Medical Research Institute of Infectious Diseases (USAMRID), "Countermeasures against Ebola Virus and Marburg Virus: Advances and Challenges."
Abstracts
Christopher Basler, "Antagonism of the Host Interferon Response by Ebola Viruses."
Several pathogenic mechanisms are though to contribute to the severity of filovirus (Ebola virus and Marburg virus) illness. These mechanisms include the ability of these viruses to suppress both innate and adaptive immunity; their ability to infect and kill many cell types, particularly those that regulate innate and adaptive immunity; and their ability to elicit strong inflammatory responses and disseminated intravascular coagulation. One noteworthy property of Ebola viruses is their ability to counteract host interferon (IFN) responses.
In particular, Ebola virus infection suppresses IFNa/b production, at least in some cell types, and it imposes a block to IFN-induced signaling pathways. These abilities are likely to facilitate, in the face of innate immune responses, the establishment of what ultimately becomes an overwhelming infection. This “IFN-antagonist” activity may also contribute to the immunosuppressive properties of Ebola virus infection.
In seeking to understand these anti-IFN properties, we identified the first Ebola virus–encoded protein capable of inhibiting IFNa/b production, the VP35 protein. This presentation will focus on the mechanisms by which VP35 blocks IFNa/b production, including its ability to block several signaling pathways that lead to the activation of interferon regulatory factor 3, a key trigger of the IFNa/b response. In addition, a possible mechanism to explain the nonresponsiveness of Ebola virus–infected cells to IFN treatment will be presented.
Daniel Bausch, "Controlling Marburg and Ebola Hemorrhagic Fevers: Where We’ve Been and Where We Need to Go."
Marburg and Ebola hemorrhagic fevers have remained mysterious diseases since the first identification of a filovirus in 1967. The natural reservoir of the filoviruses remains unknown, and no specific therapy or vaccine is available. Large outbreaks in the past decade have opened new windows into our understanding of these rare diseases, but also highlighted continued challenges and deficiencies in our control strategies.
Clues to the source of primary introduction of filoviruses into humans have been uncovered. However, most outbreaks are still primarily fueled through secondary transmission between humans from inadequate infection control practices in resource-poor countries with deteriorated public health infrastructures due to civil strife. The application of classic principles of contact tracing and quarantine have met with only partial success, increasingly meeting resistance from affected populations in need of therapeutics and vaccines.
Effective experimental therapies have recently been developed, driven primarily by industrialized world fears of bioterrorism. These products need to be expedited for field use in sub-Saharan Africa.
Thomas Geisbert, "Countermeasures against Ebola Virus and Marburg Virus: Advances and Challenges."
Ebola virus and Marburg virus, family Filoviridae, cause hemorrhagic fever with high mortality rates in humans and nonhuman primates. Currently, there are no vaccines or therapies approved for human use. Outbreaks of Ebola and Marburg have been infrequent, largely confined to remote locations in Africa, and quarantine of sick patients has been effective in controlling epidemics.
In the past, this small global market has generated little commercial interest for developing vaccines and therapies. However, heightened awareness of bioterrorism advanced by the events surrounding September 11, 2001, concomitant with knowledge that the former Soviet Union was evaluating filoviruses as weapons, has dramatically changed perspectives regarding the need for countermeasures.
In addition, progress in understanding the origins of the pathophysiological changes that make filoviral infections of humans so devastating has been slow, primarily because these viruses require special containment for safe research.
However, significant progress was recently made toward the development of an Ebola virus vaccine. Notably, recent studies have shown complete protection of nonhuman primates from Ebola hemorrhagic fever using an adenovirus-based vaccine platform. A substantial effort is being directed toward developing postexposure treatments against the filoviruses. Indeed, an increase in the understanding of the mechanisms of filoviral pathogenesis, facilitated by the development of new tools to elucidate critical regulatory elements in the viral life cycle, is providing new targets that can be exploited for therapeutic interventions.
This presentation summarizes our current understanding of filoviral pathogenesis and discusses various approaches to vaccines and therapeutic interventions based on our current understanding of how these viruses produce a lethal infection.
Reception to follow.
http://www.nyas.org/events/eventDetail.asp?eventID=3188&date=6/2/2005%205:00:00%20PM
Short answer, it doesn't. The model is specific to this case.
It seems that earlier outbreaks were contained simply because they infected relatively small, isolated villages. They "burned out" simply because everyone died.
This time the "village" is a little larger. Conceivably, the "village" is the world, this time.
I also think that weaponized smallpox is much more deadly, ie, effective, than a weaponized filovirus, simply because it is so much easier to spread a respiratory virus like smallpox worldwide
Agreed. Indeed, the truly scary scenario is a genetically modified version of smallpox. An Australian lab produced a genetically modified version of mousepox, (evidently, somewhat by accident). IIRC, they were able to introduce the interferon gene into mousepox. They then published their results in an open journal.
That version was highly contagious and evidently had a nearly 100% fatality rate as well (among mice).
Thanks, United.
That'd be a great seminar to attend. Is someone going?
Didn't find this link when I searched but it looks like some good information..
http://allafrica.com/stories/200505100167.html
HEALTH authorities in Mongu have gone on a Marburg alert after a resident of Imwiko North Park in the town died from what was suspected to be the deadly viral disease that has claimed several lives in neighbouring Angola.
And Mongu District Health Board chairman, Charles Wakung'uma has said that the provision of health services should be taken as a right.
Mongu director of health Dr. Francis Liywalii said during an interview in Namushakende yesterday that his office has carried out education and sensitisation programmes in the compound where, Mubita Nang'alelwa, who died from an acute illness and was buried at Katongo Cemetery in Mongu last week, resided.
According to investigations, the deceased had come back from a visit to neighbouring Angola sometime in January this year and some concerned residents in the town thought he could have contracted the virological disease, especially that he had bled from the mouth just before he died.
"We carried out sensitisation programmes in Imwiko North Park last week, because that is where the funeral of the man took place," said Dr.Liywalii.
Dr Liywalii was however, quick to point-out that clinical evidence did not show that the disease was Marburg, which is a virological disease that is in the same class as the Ebola virus.
He also said they have put in place preventive measures and that they will keep surveying the situation in Imwiko North Park compound in view of the development.
And the Central Board of Health (CBoH) in the Western Province has concluded a 10-day epidemic preparedness programme along the province's border areas following the outbreak of the deadly Marburg disease in neighbouring Angola.
A source disclosed that the undertaking also included the supplying of protective equipment in all the areas along the border with Angola apart from sensitising the communities in the areas that fall in the Kalabo and Shangombo districts.
The source said that the initiative was conducted with the help of neighbourhood health committees in the various communities.
The incubation period for Marburg is five to 10 days after contact, which is usually through droplet transmission and coming into contact with an infected person's body fluids, before the patient develops a fever and general body malaise. This is followed by the development of a rash and at this time the disease becomes highly infectious.
Marburg, according to expert information has claimed about 90 percent of the reported cases in Angola and is said to have become more virulent than before, and residents in Western Province fear that there might be a cross-over as has been the case with the livestock disease Contagious Bovine Pleuro-Pneumonia (CBPP).
And opening a five-week workshop for Community Health Volunteers (CBVs) and Traditional Birth Attendants (TBAs) at Namushakende Youth Skills Training Centre yesterday, Wakung'uma noted that it would be difficult to stretch health services close to the people without involving members of the community.
"Health services should be seen as a right. It is extremely difficult for health workers in the rural health centres to cover all the places, because catchment areas for rural health centres are very, very wide," Wakun'guma observed.
Wakung'uma said the role that traditional birth attendants play in ensuring the drastic reduction of death among expectant mothers during child labour could not be overemphasised.
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