Valley Fever

Valley Fever

Introduction

Valley fever refers to a fungal disease that is caused by C. posadasii or Coccidioides immitis. The infection is caused due to the inhalation of the particles. The transmission of this disease is not carried out from person to person. C. immitis are the residents of soil in some specific southwestern United States, regions of Central and South America, northern Mexico. It is developed as a mold during long dry spell with long fragments that split into airborne spores with the arrival of rain. The spores are then carried along with the rain because of the soil disruption like earthquake, farming or construction. These spores are known as arthroconidia. The infection produces immunity to re-infection (WebMD, 2012).

Discussion

Causal Agent

The casual agent of this disease is Coccidioides immitis. or C. posadasii. C. immitis refers to a dimorphic saprophytic organism which grows in the soil in the form of a mycelium and in the host organism it produces a spherule form (WebMD, 2012).

Scientific Name

The scientific name of this disease is Coccidioidomycosis. This name is preferred by most of the infectious disease physicians and microbiologists because a specific fungal disease is described with this term and in future this term will be replaced by valley fever. There are several common names for this disease like California valley fever, desert fever, San Joaquin Valley fever, Joaquin Valley fever as well as there are a few names that get confused with valley fever such as rift or African valley fever that are viral diseases.

General Characteristic of the Microorganism that Cause the Disease

Coccidioides are present in soil in the filament form. Hyphae are formed by it in both the vertical and horizontal directions. With the passage of time, cells within hyphae are degenerated and form alternating cells in barrel shape known as arthroconidia. Air currents carry arthroconidia as they are light in weight. This can easily be inhaled by the person without his knowing. When these particles arrive in alveoli, their size is increased and internal septations are developed. This developed structure is known as spherule. In order to form endospores, septations are developed. These endospores are released by the rupture of spherules with which the cycle repeats and the infection gets spread locally. Surrounding these spherules, nodules are formed in lungs. The contents are released into bronchnuts with these rupture and form thin-walled cavities. These cavities result in symptoms such as persistent cough, ...