John Galgiani, MD, Director of the Valley Fever Center for Excellence at the University of Arizona, College of Medicine explains Valley Fever; its severities and the areas where the fungus resides.
Interview conducted by Ivanhoe Broadcast News in May 2017.
What is Valley Fever? Is it fatal?
Dr. Galgiani: Valley Fever is a fungal infection and it occurs in certain parts of the country, frequently in the southwest. For instance, the Phoenix, Tucson areas are very intensely endemic for this disease, also south central valley of California, which is actually where it got its name the San Joaquin Valley of California around the Bakersfield area. The fungus grows in the soil and when things dry out, spores get out of the soil and into the air and if you happen to inhale one of these spores you’ll become infected. That occurs maybe with a frequency of one out of thirty per year. Therefore, you can live here many years and not be infected. If you get infected you have many possible courses of that infection. Many people, maybe two thirds of people, actually never get sick. They get infected, never have an illness, and become immune for the rest of their life. The other third often develop pneumonia or something that their doctors would say you have community-acquired pneumonia. That can last for many weeks to many months, but eventually most of those people get better too. However, a very small percentage of people, maybe half a percent of all infections, those patients go on to have a much more complicated disease where it goes through the bloodstream, out of the lungs to other parts of the body. when this happens, it causes infections all over the body, including in the brain, bones or skin. It can get very complicated and those people need lots of care, as it’s very possibly fatal. Actually some studies have suggested about 160 infections per year are fatal. That’s a very small percentage of the 150,000 infections we think happen each year. What is even more impacting is the morbidity of the chronic disease. Even though it’s not fatal people often have to live with disabilities and often be on treatment for years if not lifelong.
What would be the treatment?
Dr. Galgiani: Well it would be an antifungal drug. Fortunately now we have several to choose from. They can be swallowed as pills rather than taken intravenously. However, those have the drawback that none of them cure this disease, they’re all inhibitory. Ultimately it depends on the immune system kicking in and controlling this disease if in fact people are able to get off treatment at all.
The grant is helping these studies, why some people not others?
Dr. Galgiani: That’s right. We’re very excited about the new award that we got. This is work that I’ve actually been doing for several years now with a colleague at the NIH, Dr. Steve Holland. And he lives in Bethesda and works there at the NIH Clinical Center. He got interested in actually some of the patients we sent him, but others as well, finding out that these patients that have the complicated disease sometimes had genetic mutations for that. Because of that finding he’s gotten more and more interested to study more patients and that’s what this grant is going to allow us to do. It turns out that for most people who get the complicated form of this disease, we don’t have a straightforward simple gene that gets deleted or mutated. It’s going to be much more complicated. It’s probably going to be in a relationship with several genes in ways that are very subtle. We have now four years of support to start studying patients for their genetics and see not only what their genome looks like in terms of the immune response but also to look at how their genes react. We call that gene expression profiling. If we can find patterns of response even if it’s different genes where some pathway might not work as well and that’s the reason why some people get this disseminated form of disease.
You’re convinced that it is a genetic reason for everybody, it’s not anything else like geography or age or lifestyle?
Dr. Galgiani: We know there are some things that cause bad things to happen. People who have immune deficiencies for example like AIDS or organ transplantation. You’ve heard on the news of tell your doctor if you live in areas where certain fungal infections are common for the new treatments for rheumatoid diseases, we live in one of those areas. One of those diseases is Valley Fever. Those are obvious reasons why people get problems. But we don’t think there’s much difference between different strains of the fungus, it’s not that some are more aggressive than others. We think that disseminated disease is not dependent on how many spores cause the infection. If you inhale a large number of spores, you are more likely to become sick with pneumonia but not with disseminated infection. It probably is in most cases where there’s no obvious already known immunodeficiency, something about your genetic response that controls the immune response in a way that doesn’t properly control this disease.
What are you going to do with the information when you’re able to pinpoint the genetic cause?
Dr. Galgiani: Well it would be very important for a variety of reasons. One is if we could identify even before somebody got infected that they had a genetic predisposition to a complication we can tell them that. They could make decisions or if they did live where the infection is common if they got sick we would be much more aggressive treating them earlier. The other possibility is in unexpected ways once you know why people get a problem if you understand that genetics it’s part of a precision medicine that you might be able to find some specific way of preventing that. Through intervening to supplement or to restore the genetics in a way that is protected.
So your work is to be able to identify, diagnose, and also prevent. Is there something you give people or is it just a matter of them moving?
Dr. Galgiani: We’re very interested also in trying to prevent this disease in the first place through vaccine management just like polio is essentially preventive with a vaccine. We’d like to do that for our much smaller disease in Valley Fever. Since so many people get immune by the infection we should be able to do it with a vaccine. But the real question for us is for the small percentage that get complications, would a vaccine that helps everyone else actually help the ones that need it the most. The grant that we’re now funded for, part of the work we’ll do will be to look at that in mouse models. We can actually re-engineer a mouse to have some of the deficiencies that predisposes to the disseminated form of the disease and see if we could then vaccinate the mouse and prevent the disease despite that predisposition. Now if that’s the case it might suggest that everyone really does get immune but for some people it just takes longer. If that’s the case then a vaccine before you get infected might work just great even for the ones that really need it the most.
It would be a vaccine that would just be in the southwest region? It wouldn’t be something that you go to Minnesota and routinely get?
Dr. Galgiani: That’s right. If you don’t live or have exposure to this fungus there’s just no chance you’re going to get this infection. There’s good news and bad news there. In fact the market really would be the people who have residency in the endemic regions, but also tourists. We also would like this vaccine to work for dogs. Dog fanciers who bring their pedigreed dogs to shows in the endemic regions like Phoenix, they might want to have a vaccine to protect their dogs as well. I think it could be useful not only to residents in the endemic regions but people who like to go to the Grand Canyon. The disease is very similar in dogs. In fact in terms of risk they have about a three times as high risk of getting Valley Fever as does human. Cats a little bit, but not so much. Dogs are particularly susceptible and we think may be because they sniff around the ground a lot where the fungus is.
So somebody in Boston might think this isn’t going to affect them but it potentially could?
Dr. Galgiani: That’s right. If you visit the areas where this disease is endemic and that includes the lower deserts of Arizona, central California, even many parts of southern California and you return home to your area outside the endemic region, if you get an illness that your doctor says is pneumonia in the next month or so you have exactly the same risk as the people who live in the endemic region that it’s due to Valley Fever. That risk is about one out of three, thirty percent, that pneumonia is caused by Valley Fever with that exposure history.
That’s very high.
Dr. Galgiani: That’s right, it’s that common. Most people don’t get it. I mean you go through weeks and weeks without getting diagnosed with pneumonia. If you do get pulmonary syndrome and your doctor says you have pneumonia and you’ve had exposure to the fungus in the last month or so tell them you’ve had that exposure.
Where are you right now in your research?
Dr. Galgiani: We’ve actually had quite a bit of progress which is part of why they thought of funding us some more in terms of identifying specific genes. We have some patterns of small changes in genes, these are not really mutations they’re part of the human genome but very infrequent. We call them rare sequences and the term you want to use is “putatively deleterious.” Through structure they would say you know this might make the gene not work quite normally. We have these kinds of smoke. We think it’s going to be a very successful program.
Is this something that you’re actually recruiting patients for? If someone was interested in participating what would they need to do?
Dr. Galgiani: We are. We could give you a phone number they could call.
Is there anything else you would like people to know about this story?
Dr. Galgiani: This is considered by the FDA, since it’s a small market, an orphan disease. Because getting new developments for this it’s a small part of the whole healthcare problem in the United States. As you noticed, in the endemic regions, it’s anything but rare. It’s a third of pneumonias. Here we have this orphan disease, where it occurs, it is highly common. I think awareness of this is very important both for the medical community but just as importantly for the people who have the risk, and live or travel to the endemic regions. That in itself will put them in better shape so that if they get an illness they’re more likely to get an early diagnosis. If we can get the vaccine made then we could prevent this thing entirely.
END OF INTERVIEW
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