Notes from the field: Histoplasmosis!

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Histoplasma capsulatum in situ (Photo credit: Wikipedia)

I was very excited this week to receive my Centers for Disease Control and Prevention update. This week in the Morbidity Mortality Weekly Report: “Histoplasmosis outbreak among day camp attendees–Nebraska, June 2012.” My excitement was mainly due to the fact that it was about a fungal disease, and one that I actually know someone who had an infection due to the organism.

Histoplasma capsulatum is one of the 4 primarily pathogenic fungi discussed in Bauman; these species of fungi are generally only found in the presence of disease in humans, and do not share a commensal relationship. Fortunately, most disease in humans tends to rather mild and readily treatable, however complications can occur particularly in immunocompromised individuals. Most fungal infections in humans are not contagious from person-to-person, so outbreaks in a community are generally the result of a mass environmental exposure. Histoplasmosis is considered an endemic disease throughout the Midwest and Eastern United States, particularly in the Mississippi and Ohio River valleys. Major risk factors for developing histoplasmosis include coming into contact with bird or bat droppings. Symptoms include fever, headache, and respiratory presentation, however complications can involve multiple body systems.

The current outbreak detailed in MMWR describes a group of camp counselors from Omaha, Nebraska who became sick with fever and acute respiratory illness in mid-June 2012. Positive cases were diagnosed either by serum or urine test anytime after arrival at the camp. Thirty-two counselors were positive for Histoplasma and showed varying levels of symptoms. No hospitalizations or deaths occurred. Screening of camp attendees indicated that just over 11% of campers in close proximity to the sick counselors also had detectable levels of Histoplasma with case defined disease. Infection of campers and counselors likely occurred at two campsites that had noticeable bat guano at a campground shelter, and presumably the pre-camp cleanup carried out by the counselors contributed to the aerosolization  of fungal spores that diminished in numbers the further you got from the contaminated campsite.

Following this outbreak, the city Parks and Recreation Department relocated the day camps to another park. The Department of Health’s recommendation was threefold: 1) to prevent bat roosting in these areas, 2) to better identify potentially contaminated areas, and 3) to further develop ways for decontaminating biohazardous sites while maintaining the safety of the public. My colleague in graduate school who was diagnosed with histoplasmosis never knew how it was acquired, and by and large was completely asymptomatic. The only reason that the infection turned up was due to a health screening x-ray for a new job, which showed a spot on the lung. Turned out that histoplasmosis was a far, far better diagnosis than lung cancer.

BONUS:  Because we typically run out of time at the end of the semester, fungi can get short shrift in BIO230. To remedy this and have a quiz grade raised to a “5”, list in the comment thread:

1) a fungal pathogen, 2) how it can be acquired, and 3) how it might be treated

Note: all submissions must be new and original in the thread, so read what others have put down, and no one put down Histoplasma capsulatum!


BONUS all done: Fall break is imminent!


About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on October 3, 2012, in Bonus!, Microbes in the News and tagged , . Bookmark the permalink. 31 Comments.

  1. Bastomycosis or Blastomyces dermatitidis is a fungal pathogen popularly found in parts of the U.S. and Canada. It normally grows in soil and humans acquire it due to exposure of the fungal spores becoming airborne and inhaled. It is usually more common in the immunocomprosmised (such as those with AIDS) and causes issues with the skin, bones, or nervous system. It is also commonly diagnosed in pets such as dogs. This fungal infection is often treated with the use of amphotericin B for 10+ weeks which, as we recently covered in lecture, attacks the membrane structure and ergosterol of fungi.

    (Bauman 2011)

  2. Mackenzie Pratt

    Aspergillus flavus is a fungal pathogen that produces a toxin called aflatoxin. It can be found in crops such as corn and peanuts and humans, as well as animals, can get aflatoxicosis by consuming contaminated these crops. It may cause abdominal pain, vomiting, convultions, liver damage and sometimes may lead to death. In humans the treatment is usually an antifungal medication like amphotericin B.

    • I had a graduate school mentor who never would eat peanut butter, which outside the United States is a major vehicle (that is a Chapter 14 term!) for aflatoxin delivery into humans. Since Prof. Sudilovski spent his medical career looking for a cure for hepatic cancer, and since aflatoxin is HIGHLY associated with liver cancer, I do not blame him for his caution.

  3. Michele Taylor

    Coccidiomycosis, caused by Coccidioides immitis, is a fungal pathogen. This pathogen is isolated to the southwestern United States and northern Mexico. The fungi can be picked up from soil, rodent burrows, and mines. Unfortunately, the fungi is easily spread through tourist purchases, such as pots and blankets. It is also known to be spread through off roading vehicles and windstorms. When the fungi is inhaled, a parasite is produced in the lungs. This will grow and multiply. Many times the infection can go unnoticed and untreated, making the infection resolve itself. However, there are a range of symptoms that can be seen. When this occurs, amphoterican B is typically used.

  4. Hannah Ritzman

    Paracoccidioides brasiliensis, which causes paracoccidioidomycosis is a chronic fungal disease similar to blastomycosis and coccidioidomycosis (described above). Found in the cool, damp soil of southern Mexico and regions of South America (especially Brazil), P. brasiliensis is acquired by inhaling airborne fungal particles. Those most at risk include farm workers, but because this fungus is limited geographically, P. brasiliensis is not a common disease. Treatment for this fungal pathogen is with amphotericin B or ketoconazole.

    (Bauman 2011)

    • Paracoccidioides is number 4 of the “Big Four,” and like Coccidioides if a patient in Pennsylvania presents with the disease, the first question you would ask is “Did you just get back from the Southwestern US?”

  5. Blastomyces dermatitidis is a fungus that lives in the Midwestern to Southern United States. This fungus grows in the soil surrounded with rotting vegetables, or animal waste. Blastomyces dermatitidis enters in the lungs, and causes coughs, fever, chills, and weight loss. Eventually this develops into purulent lesions, killing the surrounding tissue, leading to respiratory failure. This can be treated with amphotericin B or intraconazole.

  6. I picked this website up form a google alert of histoplasmosis. I have Fibrosing Meidastinitis post histoplasmosis. Mine was diagnosed in January of 1985. I am now disabled with comorbidities. An issue I feel FM patinets have is getting a timely diagnosis. During a recent conference on FM I heard three physician speakers answer why to the lengthy diagnosis. It was rare and they weren’t familiar with histoplasmosis and thus didn’t suspect I guess FM. Of course these doctors learned to and they all were expert speakers. So your comment about not worrying about Coiccidiodes because it wasn’t endemic rang loudly to me. Also, the whole issue of running out of course time so you come up with a catchy way to cover the fungus’s. Of course the body generally resolves these things. But we have had an individual die earlier this year from Fm post coiccidiodes and a 16yo girl this past June died in Minnesota while out jogging. She was being treated for asthma but through an autopsy, found to have died from pulmonary artery vasculitis from FM post histoplasmosis. These days many people relocate and it seems to me that all things through this course work should be learned and remembered and become a suspicion through the differential diagnosis. Many of the people with FM have inoperable conditions because they have had FM developing for years after they had histoplasmosis. The inoperable part significantly alter quality of life through SVC syndrome, pulmonary hypertension, Bronchial trachea and esophagus obstruction.

    • Welcome from the Internet. Coccidioidosis certainly is an endemic disease in the southwestern United States and Mexico, it is just not found here in southern Pennsylvania. Any presentation of Coccidioides locally is almost certainly going to be transplanted by the patient from an endemic area, and a detailed patient history would hopefully turn that up.

  7. Gabrielle Petrancuri

    Athlete’s foot is a type of fungal infection, most commly stemming from the fungi Trichophyton rubrum. This type of infection is acquired because it thrives in a moist, warm, and wet enviroment such as shoes, socks, swimming pools, and locker rooms and is contagious. Signs and sysmptoms vary from person to person but most people have peeling, cracking, and scaling of the feet. Athlete’s foot is treated with topical antifungal medication in most cases.

    • Trichophyton is in the class of fungi known as dermatophytes, and are common inhabitants of the skin. They are interestingly enough only one of the two main classes of fungal pathogens that are communicable, or readily easy to pass from infected individual to individual. Most fungal infections are not communicable.

  8. Thrush is a common fungal infection of the mucous membranes, in the cases I personally witness in the retirement facility I work at, they are seen in the mouth. The main fungus seen in these cases is Candida albicans. C albicans is a harmless commensal organism inhabiting the mouths of almost 50% of the population, however under certain circumstances can become an opportunistic pathogen. Thrush may be observed in healthy neonates or in people who antibiotics, corticosteroids, or xerostomia disturb the oral microflora. Immunocompromised people are at greatest risk for this especially those who have HIV infection, immunosuppressive treatment, leukemias, lymphomas, cancer, and diabetes. Thrush presents as white patches in the mouth and tongue and is very painful. These white patches can be wiped away however this normally exposes ulcers that are red and tender and often bleed. The treatment for this normally is an antifungal wash normally nystatin swish and swallow, however the best defense is prevention in these cases. By assuring good mouth care and as a nurse making sure our patients swish and spit after we administer corticosteroids, such as Advair inhalers, we can prevent many cases of this.

    • Here is a Pubmed citation detailing the definitive work examining the role of outer chain carbohydrate modification in the Candida albicans cell wall. Good Stuff!!!!

      And this is the second of the fungal pathogens that are communicable. Most humans acquire Candida albicans from their mother during the birth process and shortly after birth, and become colonized in a commensal relationship for their entire lives.

  9. Cryptococcus albidus. It is an endemic to the contiments Africa and Australia. It is common on human skin and is reported to cause pulmonary, CNS and vaginal infection.

    • The type species of Cryptococcus is Cryptococcus neoformans. Like C. albidus, it is a cause of meningitis, however it is much more prevalent and is considered endemic worldwide. Infection due to C. neoformans is a hallmark of HIV infection, and is considered an AIDS-defining illness.

  10. 1.) Fungal Pathogen: Cryptococcus neoformans
    2.) Acquired: Through soil contaminated with bird feces, creating lung infections.
    3.) Treatment: Fluconazole- a triazole antifungal drug that treats fungal infections.

    • Going to also disallow this one, as Prof. Singleton threw out C. neoformans just above at 2:28 PM! Although it is acquired through the respiratory tract, the primary pathology of the disease is in the central nervous system as the primary cause of fungal meningitis.

  11. Sporothrix schenckii is a fungal pathogen that creates an infection known as Sporotrichosis. It thrives in soil, plants, and decaying vegetation. It most commonly causes a skin infection through small cuts or punctures, but if a person inhales microscopic fungal spores, a pulmonary infection can occur as well. Symptoms include a small painless bump that looks like a bug bite, red, pink or purple in color, and will increase in size resembling a ulcer or open sore that takes a long time to heal. For a pulmonary infection pneumonia can develop with symptoms like shortness of breathe, cough, and fever. Treatment is most commonly antifungal therapy.

    • Learned something new by Googling Sporothrix: it is a dimorphic fungus, so I would therefore lump it into the “Big Four” group because of that property. Who knew?

  12. 1.)Fungal Pathogen: Rhizopus oryzae
    2.)Acquired: Found in dead organic matter that create a skin fungal infections commonly found in the nose and mouth, potentially life threatening.
    3.)Treatment: Triazole antifungal drugs

  13. Korissa Lincoln

    Geotrichum candidum is a fungal pathogen that is commonly found in plants, diary products, and animals (such as meats). Humans can contract this fungi by eating any of these products that contain Geotrichum candidum. In order to treat this fungal infection, the patient is given a prescription of amphotericin B.

    • I actually have Geotrichium candidum growing on a plate in the Micro prep room right now. Every just might get the chance to see it during the practical!

      Going to have to teach people how to put in italics into the comments for species names. It’s actually pretty easy, you just put the word to be italicized between <em>-tags like this: <em>E. coli</em> will print out as E. coli.

  14. Christa Gurriera

    Tinea Cruris is a fungus that grows and spreads in the groin area, because this fungus thrives in warm, moist places. This mostly occurs in adult men and adolescent boys. It can be initiated from friction and sweat after workouts and is commonly found in athletes. Jock itch is contagious by direct contact. The symptoms include itching, raised scaly patches, and abnormally dark or light skin. The treatment is to keep the infected area clean and dry, don’t wear clothes that rub or irritate the skin, and to apply topical anti fungal or drying powders continually to the area.

    • I want everyone to imagine those “hyphae” of molds that we saw under the microscope. And now I want everyone to imagine hyphae growing in and around the cells of the epidermis, penetrating into the upper levels of the skin. Because that’s what these guys do.

  15. Candida species normally infect people that are immunocompromised which includes people who have had transplants, AIDs and cancer patients. Everyone has Candida in their gastrointestinal tract and it only becomes a problem when it grows too much and goes into the bloodstream and is then able to harm vital organs. The fungus is kept under control by bacteria but if those bacteria are not working properly, the fungus will grow out of control. Candida is typically treated by antimycotics, which are anti-fungal drugs.

    • Again going to have to disallow this comment, as Lynn B up above here already put down Candida albicans. Furthermore, no one in the class has clicked this link to read some groundbreaking research from a member of the York College faculty directly relevant to this very important pathogen.

  16. Ashley Chenoweth

    Tinea corporus is a fungal disease also known as “ringworm of the body.” Although the name suggests that is an infection from a worm, it is not. It is actually a fungal infection that accumulates on the epidermis of the skin. This fungus is contagious by touch and the symptoms are round, red spots (common for any type of ring worm), some of these red spots grow slowly. However, ringworm rings are hard to distinguish from other infections and because it is a fungal infection, it will need a different treatment from say a bacterial infection. If it it ringworm, there are no homeremmedies that will cure the infection. The only way to get rid of the fungal infection is to use a cream or, now, you can take the anti-fungal medicine orally because some fungal infections don’t respond to external applications.

  17. Onychomycosis is a fungal nail infection that is caused by a fungal pathogen called Tinea unguium. This is similar in nature to “Athlete’s foot” and “Jock itch.” This is most often seen in adults, and usually on their toe nails not their fingernails, although both are possible. Surprisingly, getting pedicures with dirty equipment can infect you with this, so be careful where you go ladies! Like most diseases, a compromised immune system patient is at greater risk, and like most fungi, the area must be moist and often happens because of wearing a lot of close-toed shoes while sweating. The symptoms include brittleness, crumbling, change in shape, thickening, yellow streaks and more of the nail. Usually the nail looks like it has a problem, this is very obvious and usually very unattractive; it can become painful if ignored. Since it is so easily seen, a physician can usually diagnose by the appearance of the nail, but confirmatory tests can be done by scraping the nail and looking at it under a microscope (scotch tape method!). Treatments are usually over-the-counter creams but it takes a really long time of daily application to be effective. The old infected nail has to grow out completely. In extreme cases they can remove the nail. Unfortunately, even if treatment seems effective, it often returns to that nail or somewhere else. This is a link to a picture:


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