LHF - Trying to understand an Obscure disease.

[psychotick]

Hi,

There's a lot we don't know about this illness I'm afraid. But yes these cases you mention are individual cases. And two of them at least are unconnected with the others.

Your two lab infections, are - at least in one case - associated with mice infected with the virus. The reality is that this is dangerous work and should have been done under stringent bio-control conditions. The fact that we have two people infected indicates that there was a mistake made somewhere, and mistakes in micro labs are often extremely serious. The innoculum from a cut for example is often larger than would be received through normal exposure routes, and the viral strains may vary. However the real question you need to ask, going back always to the statistics - is how many people working in that lab were exposed to the pathogen, how many became ill or developed an antibody responce, how many didn't, and how many died. We don't have that data.

The autopsy is an interesting route of exposure, and again if it was known that the patient had died of a viral haemorragic fever, should have been done under extremely controlled conditions. My guess is that it wasn't. And again the severity of the illness experienced from cutting open a body saturated with virus particles, was always likely to be high.

Laura Wine in all probability did not pick up the illness from contact with her unknown patient. That is not the normal route of infection for the illness. It's unfortunately more likely that there were rats and rat faeces in the clinic / hospital. Unfortunately in countries like those in West Africa hospitals are often extremely primitive.

This may also have applied to conditions in Bingham Hospital in Nigeria - though since its currently a teaching hospital attached to a university, I would hope not. However, forty or fifty years ago? I don't know.

The stats for morbidity and mortality in hospital admissions are worrying, and as you say they do seem high. But remember these are people who have been admitted to hospital. So as an example if twenty percent of people with the illness are admitted to hospital, and fifteen percent of them die, that is actually only three percent of all cases. Further the deaths are likely associated with the level of care received by patients, and the timeliness with which they arrive in the hospital. Many people do not go at all, or only if they are already at death's door.

Cheers, Greg.

 

[Sheilawisz]

That's an interesting point of view, Greg.

It's very likely that the LHF infections acquired in hospital and laboratory settings tend to be severe because they have cut their finger, pierced their skin with a contaminated needle or something like that. That would introduce a larger number of pathogens into the body, even right into the bloodstream and this would explain why this causes the malignant form of the disease.

The severity of the infection would depend on the route of exposure to the agent.

I have read from some sources that catching the disease from food contaminated with rat urine is also particularly dangerous. Maybe other, more common methods of exposure result in the mild forms of LHF that are far more widespread, but I have another interesting theory:

You know that Dengue Fever is usually a mild disease, but the danger of developing the malignant Dengue comes when a person is repeatedly infected by different strains of the virus. I am not sure how it works, but I know that this is how Hemorrhagic Dengue develops and then the life of the person becomes endangered.

Do you think that something similar could be happening with Lassa Fever?

Penny Pinneo's antiserum saved lives, but eventually it was discovered that it didn't work in patients sickened by strains of LV different to the one that she became infected with. Perhaps getting one of the strains for the first time results in mild disease, and the malignant form develops when the same person catches a different strain.

What do you think of this?

According to the book The Coming Plague by Laurie Garrett, only Jordi Casals was authorized to work inside of the Lassa laboratory of Yale University. It remained unclear how Juan Roman had caught the disease, but surely there was an accident at some point during the research.

Juan Roman's death finally convinced Yale to stop their LHF program and send their remaining samples to the CDC.

 

[psychotick]

Hi,

Dengue is an interesting illness - and one much closer to my home literally as I live in New Zealand. No one really knows why in up to five perecent of cases Dengue fever goes onto become Dengue Haemorragic Fever, or why it seems to be associated with previous infection with another strain. The current hypothesis is a thing called Antibody Dependant Enhancement, but the mechanism behind this is unclear.

One suggested mechanism is that those previously exposed to previous strains and with antibodies developed to that strain then react to the new strain with the old antibodies, and that this is a mistake. The new strain of the virus and the antibodies to the old strain, are not a good match, and the resultant binding is damaging to white blood cells leading to capillary collapse.

Could something similar be happening in the case of Lassa Fever? Maybe. But there is no evidence for it. No evidence that previous infection with one strain of the disease makes infection with another strain more dangerous.

Cheers, Greg.

 

[stephenspower]

"The United States shipped crates of homeless cats down to Bolivia and the plague stopped."

I'm going to spend some time looking into this. Sounds as fascinating as the bat bomb program.

 

[stephenspower]

BTW, I presume you've read THE HOT ZONE, which is amazing. I wouldn't recommend you do so on a plane, like I did.

 

[Sheilawisz]

Greg, New Zealand is one of the countries that I want to visit someday.

The landscapes look fantastic in the Lord of the Rings movies, and I think that also The Hobbit and the Narnia movies were filmed there. I know that New Zealand also has excellent mountains to practice climbing and skiing, so yeah, it sounds like a wonderful place from my point of view =)

I did not know that you had risk of Dengue Fever there.

There is also a considerable danger of Dengue where I live, but not in my city because we are 2400 meters above sea level and the responsible mosquitoes cannot survive up here. It was very surprising when a nearby city suffered an outbreak not a long time ago, because they are 1800 meters high and they should have been safe...

It's intriguing that there is no vaccine against Dengue, and also there is no drug that can attack it directly.

@Stephenspower: I have read The Hot Zone indeed, a long time ago and also recently. I have a strong dislike for that book because it's not really a scientific account of the diseases described in it. Richard Preston is a powerful narrator, but The Hot Zone is a Thriller with a sensationalistic approach designed more to scare people than to inform them correctly.

The Coming Plague is a more complete and scientific book, I recommend it a lot if you are interested in obscure diseases. There is also a book all about LHF called The Lassa Ward by Ross Donaldson, but unfortunately I have never had a chance to read it.

My story Winter Hollow is coming soon to the Showcase, I promise!

 

[psychotick]

Hi,

No we don't have Dengue here. We don't have the mosquitoes. What we do have are a lot of visitors from the islands like Fiji and Samoa.

Cheers, Greg.

 

[Caged Maiden]

one other thing I want to mention is Valley Fever, a disease common in the American Southwest. I lived in Albuquerque for the last seven years, and I went camping all over and was generally out and about there. When I went to Arizona for a camping event, it was the first time I heard of Valley Fever, but my friends warned me that I might come home sick.

Valley Fever is a fungus found in the soil in the area, and it gets into the lungs when you breathe in dust. They recommend you wear a mask if your immune system isn't strong, but nothing else. Well, other than a few people coming home with cold-like symptoms that last a few weeks, nothing happened on our trip, but the CDC says if you're exposed, you can see your doctor for treatment with an anti-fungal medication and be back to full health within a week

I was watching a program called Monsters Inside Me, where a woman got Valley Fever and she had a terrible illness. Open sores, physical weakness. She was incapacitated and the fungus tore her up. Not only that, but there are other accounts of people visiting the southwest and going home and having severe responses. SOme actually suffer severe, permanent mobility issues. How in the world does that happen? One young man went to college in Albuquerque and he returned home to the East Coast when he became ill. THey spent eight months trying to figure out what was physically crippling him, and finally the doctor found it was Valley Fever. That was ten years ago and his mother says he aged twenty years in the one year, and now he's got severe arthritis and can hardly walk. WHy would something that affects most people mildly, cause that kind of reaction?

Most people exposed get no symptoms or very mild ones. Some people can have cold-like symptoms that last a few (up to six) weeks. Then there seem to be some extreme cases that just baffle me, how they can all be caused by the same fungus.

 

[psychotick]

Hi,

Had never even heard of this disease before and had to do some quick fact checking - so please bear that in mind. But basically it is a fungus as you say that grows in the soil - the correct term for the disease is coccidiodomycosis - and it seems to follow the same basic rules as other fungal diseases such as stachybotris (the one found in rotting wall cavities in damp ridden homes).

Essentially the severity of the illness depends on a couple of factors. The first is the dose or inoculum. And that in turn will depend on many things. First how long was the person exposed to the fungal spores? A few hours hiking or a week camping? Was the soil disturbed in any way? Ie people digging the soil say to build house foundations etc, will be exposed to a lot more spores than others because the digging releases the spores. Weather conditions may also be important since fungi find certain conditions - damp? warm? and dark? - preferable for growing in. Of course different fungi like different conditions - hence the question marks.

Next is the health of the person. Most people exposed to this fungu and who develop the illness will recover naturally and relatively easily from a mild illness. But for some it may be more serious. These people will generally have some sort of condition that affects their imunity. Thus people suffering from AIDS, those on certain drugs (steroids) that depress the immune function, the elderly and diabetes sufferers are at greater risk. There also appears to be some difference in genetics such that people of certain races are more suceptible to it. And pregnant women as well. I suspect, though I coul not find any references to it, that lung health will also play a role. Those with damaged lungs from say smoking, will probably be at greater risk.

Now for the illness itself, this will vary. Sixty percent of those exposed do not get ill. (They may however still develop an antibody response, which will make them imune to the disease if they are exposed again.) Most of the rest will develop a flu like illness lasting perhaps a few weeks. Typically this includes fever and breathing issues - the sort of thing you would expect if a foreign micro-organism was in your lungs trying to set up home. The fever is generally an indication of infection. A rash is also common. More serious illness in other parts of the body, means that the fungus has travelled from the lungs into the body, and the infection has become what's called systemic. This would generally only happen in someone with a compromised immune system.

As for the arthritis, that sounds like an immune response over reaction to me. (Guessing a little bit here.) Certain diseases such as campylobacter, in rare cases can trigger the immune system to over react, and sometimes that over reaction can include off target actions - ie the antibodies start identifying certain body tissues as non-self and attack them. Arthritis is a form of immune misfire where the tissues of joints are attacked by the body's own antibodies.

Cheers, Greg.

 

[Sheilawisz]

Hello Maiden, it's good to see you posting in this thread again.

I have watched Monsters Inside Me too, and I enjoy the show a lot. It's a little creepy sometimes and I am often surprised at the carelessness of many of the people involved in those cases, but in general it can be very engaging.

Now that you mentioned it, I watched that Valley Fever episode some time ago. We almost never consider the possibility of a destructive Fungus agent... It's a different possibility.

Maybe somebody should write a story about a dangerous Fungal pandemic instead of a virus or a bacteria.

Meanwhile, I continue to seek for new and updated information about Lassa Fever for my story. I found something quite interesting last night, but I'll talk about that in a different post.

 

[Sheilawisz]

Hello, everyone.

I am not sure of how I could use this in my story, but new research efforts have recently discovered a potential weakness in the way that LV operates. It seems that the virus uses an unexpected two-step process to infect cells within a person, and that could open the door to new treatments.

Please check out this link: Army research sheds light on Lassa Fever.

How about that?

They could soon figure out a way to prevent LV from causing pathogenic effects, rendering the virus inactive by blocking its access to cells. I know that any new medication needs years and years of development and trials and so on, but it's good news anyway.

Also, I have noticed that this source in particular speaks against the common practice of downplaying and underestimating LHF. It clearly says that the mortality rates are between 20 and 50%, also giving numbers of up to a hundred thousand fatal victims every year.

It's time for the world to wake up and realize the threat.

I am not very sure about such high numbers of damage, but I am sure that they are more realistic than other sources. Why this Lassa Fever thing is rarely spoken about, downplayed and ignored by most of the world, is beyond my understanding.