Description

Aspergillosis  is a fungal disease that in dogs is caused primarily by Aspergillus fumigatus. Infection is usually in the nasal cavity. Typical signs in dogs include sneezing, nasal discharge, bleeding from the nose, and ulcerations of the nose.

Symptoms

A fungus ball in the lungs may cause no symptoms and may be discovered only with a chest x-ray. Or it may cause repeated coughing up of blood and occasionally severe, even fatal, bleeding. A rapidly invasive Aspergillus infection in the lungs often causes cough, fever, chest pain, and difficulty breathing.

Aspergillosis affecting the deeper tissues makes a person very ill. Symptoms include fever, chills, shock, delirium, and blood clots. The person may develop kidney failure, liver failure (causing jaundice), and breathing difficulties. Death can occur quickly.

Aspergillosis of the ear canal causes itching and occasionally pain. Fluid draining overnight from the ear may leave a stain on the pillow. Aspergillosis of the sinuses causes a feeling of congestion and sometimes pain or discharge.

In addition to the symptoms, an x-ray or computerised tomography (CT) scan of the infected area provides clues for making the diagnosis. Whenever possible, a doctor sends a sample of infected material to a laboratory to confirm identification of the fungus.

Diagnosis

On chest X-ray and computed tomography pulmonary aspergillosis classically manifests as an air crescent sign.  In hematologic patients with invasive aspergillosis the galactomannan test can make the diagnosis in a noninvasive way.

On microscopy, Aspergillus species are reliably demonstrated by silver stains, eg, Gridley stain or Gomori methenamine-silver.  These give the fungal walls a gray-black colour. The hyphae of Aspergillus species range in diameter from 2.5 to 4.5 µm. They have septate hyphae, but these are not always apparent, and in such cases they may be mistaken for Zygomyces.  Aspergillus hyphae tend to have dichotomous branching that is progressive and primarily at acute angles of approximately 45°.

Treatment

The favored treatment with the fewest side effects, such as nephrotoxicity, is voriconazole, according to the Kaplan Qbank.

Other drugs used are amphotericin B, caspofungin, flucytosine, itraconazole are used to treat this fungal infection. For severe cases of invasive aspergillosis a combination therapy of voriconazole and caspofungin is suggested as a first line treatment.

Infections in animals

Albeit relatively rare in humans, aspergillosis is a common and dangerous infection in birds, particularly in pet parrots. Mallards and other ducks are particularly susceptible as they will often resort to poor food sources during bad weather.

Aspergillosis has been the culprit in several recent rapid die-offs among waterfowl. From 8 December until 14 December 2006 over 2,000 Mallards died in the Burley, Idaho area, an agricultural community approximately 150 miles southeast of Boise. Moldy waste grain from the farmland and feedlots in the area is the suspected source. A similar aspergillosis outbreak caused by moldy grain killed 500 Mallards in Iowa in 2005.

While there is no connection between aspergillosis and the H5N1 strain of Avian Influenza (commonly called "bird flu"), rapid die-offs caused by aspergillosis can spark fears of bird flu outbreaks. Laboratory analysis is the only way to distinguish bird flu and aspergillosis.

Wikipedia and GNU

The content of this entry is from the Wikipedia article "Aspergillosis" licensed under the GNU Free Documentation License.