1. Fungal Infections

2. Histoplasmosis Systemic infection by Primary pathogen
Causative agent: Histoplasmosis capsulatum
Most common true pathogen
Typically dimorphic
H. capsulatum grows in soil and material contaminated with bat or bird droppings. (droppings from chickens, pigeons, blackbirds also support its growth)
The microscopic fungal spores can become airborne when the soil is disturbed, and breathing in the spores can cause infection in the lungs
Most prevalent in eastern & central regions of the US

3. Histoplasmosis
H. capsulatum thrives in moderate temperatures & moist environment
Cannot be transmitted from person to person
Many people who are infected with the fungus do not show any symptoms 
If symptoms occur, they usually start within 3 to 17 days after being exposed to the fungus
In people who develop disease, the most common symptoms are similar to those of pneumonia, and include: fever, chest pains, and a dry or nonproductive cough

4. Histoplasmosis Multiple tests available to diagnose Histoplasmosis
Blood
Sputum
Bone marrow
Liver, or skin
By looking at a small sample of infected tissue under a microscope
The mild pulmonary (lung) form of histoplasmosis will generally resolve within about a month without treatment.
Prescription antifungal medications are needed to treat severe cases of acute histoplasmosis, and all cases of chronic or disseminated disease

6. Coccidioidomycosis: Valley Fever
Systemic infection by Primary pathogen
Causative agent: coccidioides immitis
The most virulent of all fungal pathogens
Distinctive morphology
Blocklike arthroconidia in the free living stage & spherules containing endospores in the lungs
Lives in the soil of dry, low rainfall areas

7. Coccidioidomycosis: Valley Fever
The disease is found mainly in the southwestern United States, Mexico and Central and South America
Dry weather coupled with sparse foliage and high winds provides the ideal condition for the spores to be airborne
Transmission is generally by inhalation of spores found in the soil in endemic areas

8. Coccidioidomycosis: Valley Fever
In 60% of cases infection is asymptomatic
In 40% of cases include
flu-like symptoms (cough, fever, sore throat, chills, headache, and in some cases itchy rash) that go away on their own
Rare (5/1000), advanced coccidioidomycosis includes: skin lesions, chronic pneumonia, bone or joint infection
Imaging tests- CT scans, x-rays of the lungs
In many cases, treatment is not necessary
Prescription of antifungal medications, such as amphotericin B & fluconazole, to prevent a more severe infection from developing

10. Dermatophytes Pathogens with Intermediate virulence
Derma “skin” and plant “phyte”
Common fungal infections that may occur anywhere on the skin, hair, and nail infections.
All are communicable diseases
Among humans, animals, and soil
Many different species of dermatophytes that can cause infection in humans. Two of the most common types are Trichophyton rubrum and Trichophyton tonsurans, which are usually transmitted from person to person.
T. rubrum
T. tonsurans

11. Dermatophytes
Dermatophytes like to live on moist areas of the skin, such as places where there are skin folds.
They can also live on household items, such as clothing, towels, and bedding.
Most diseases are termed “ringworm” or tinea because they develop in circular scaly patches

12. Dermatophytes
The work tinea followed by the Latin term for the part of the body infected, is often used.
Tinea capitis (head) Tinea corporis (body)
Tinea pedis (foot) Tinea manuum (hand)
Tinea unguium (nail)

13. Tinea capitis Sometimes called “ringworm of the scalp”
Primarily affects school-aged children
More common in large cities and overcrowded conditions
Reservoir for most organisms is humans , some have animal hosts
Incubation is 10 to 14 days

14. Tinea capitis Transmission Symptoms By direct or indirect contact
Backs of theater seats
Barber clippers
Combs/hairbrushes
Clothes
Animals can also transmit the infection and sometimes are carriers
If the infection involves the scalp or beard, hair may fall out
Begin as small papules and spread across the head
Hair in the infection area become brittle and break off easily

15. Tinea capitis Diagnosis is through physical examination
Particular medication and duration of treatment depends on the location of the infection
Topical treatment alone usually is ineffective and is not recommended for the management of tinea capitis
Scalp infections usually require treatment with an oral antifungal medication (for at least 4 weeks)
If secondary infection, antibiotics can be used

16. Tinea pedis Fungus infection of the foot especially between the toes
Commonly called “athlete’s foot”
Most common of all fungal skin diseases
Infects adults more often than children, and males more often than females
More often and more severe in hot weather
Warm, moist conditions (between sweaty toes)

17. Tinea pedis Transmission Symptoms
By direct or indirect contact with skin of an infected individual or lesion of infected animals
Floors, shower stalls, benches, and similar location can also be a source of infection
Scaling or cracking between the toes and watery blisters
In severe cases- lesions may appear on other parts of the body particularly the hands
Itching can be severe
Exposure to public surfaces

18. Tinea pedis Based on symptoms and physical examinations
Can be treated with topical antifungal medications.
Fungicide in salve or powder form should be applied after every bath or shower
Salve is a lotion ointment or paste

19. Candidiasis- “yeast infections”
Infection by Secondary pathogen
Causative agent: most common is Candida albicans
Infections can be short-lived, superficial skin irritations to overwhelming, fatal systemic diseases
Budding cells of varying size that may form both elongate pseudohyphae and true hyphae

20. Candidiasis
Candida yeasts normally live on the skin and mucous membranes without causing infection
Overgrowth of these organisms can cause symptoms to develop
Candidiasis is usually endogenous
Can also be communicable

21. Oropharyngeal Candidiasis
Candidiasis that develops in the mouth or throat is called “thrush” or oropharyngeal candidiasis
The most common symptom is white patches or plaques on the tongue and other oral mucous membranes
Other symptoms include:
Redness or soreness in the affected areas
Difficulty swallowing
Cracking at the corners of the mouth (angular cheilitis)

22. Oropharyngeal Candidiasis-Symptoms
Uncommon in adults who are otherwise healthy
Can affect normal newborns
Newborns can develop thrush from mothers with a vaginal “yeast infection” at delivery
Symptoms begin 7-10 days after birth
Diagnoses based on symptoms
Taking a scraping of the affected areas to examine under a microscope
Candida infections of the mouth and throat must be treated with prescription antifungal medication
The type and duration of treatment depends on the severity of the infection

23. Candidiasis-Genital/Vulvovaginal
Genital / vulvovaginal candidiasis (VVC) is also sometimes called a "yeast infection.”
Occurs when there is overgrowth of Candida
Imbalances
Normal acidity of the vagina changes or when hormonal balance changes
Transmission: endogenous infection or contact with excretions or secretions of infected individuals
Women with VVC usually experience genital itching, burning, and sometimes a "cottage cheese-like" vaginal discharge
Men with genital candidiasis may experience an itchy rash on the penis
Candida can multiply

24. Candidiasis-Genital/Vulvovaginal
Nearly 75% of all adult women have had at least one "yeast infection" in their lifetime
Wearing cotton underwear may help to reduce the risk of developing a yeast infection.
Symptoms are similar to those of many other genital infections
can be difficult to diagnose a yeast infection by physical examination only
Usually the diagnosis is made by taking a sample of the vaginal secretions and looking at the sample under a microscope to see if an abnormal number of Candida organisms are present

25. Candidiasis-Genital/Vulvovaginal
Treatment
Antifungal vaginal suppositories or creams are commonly used
Duration of the treatment course of creams and suppositories can range from one day to seven days of therapy
Mild or moderate infections can sometimes be treated with a single dose of oral antifungal medication
Over-the-counter treatments for VVC are available

26. Aspergillosis Infection by a secondary pathogen
Causative agent: Aspergillus
Distinguished by septate mycelium with characteristic conidial heads
Common fungus that can be found in indoor and outdoor environments
Found in soil, on plants, and on decaying organic matter
Also found on household dust, and building material
Aspergillus flavus

27. Aspergillosis There are many different species of Aspergillus
Aspergillus flavus
There are many different species of Aspergillus
8 involved in human disease
Most common species are Aspergillus fumigatus and Aspergillus flavus
Different kinds of aspergillosis
allergic bronchopulmonary aspergillosis (also called ABPA)
aspergilloma
invasive aspergillosis
Transmission: through inhalation of spores
Most people breathe in Aspergillus spores every day without being affected
Inhalation of spores causes fungus balls in lungs and invasive disease in the eyes, heart, & brain

28. Aspergillosis
The different kinds of aspergillosis can cause different symptoms
Symptoms of allergic bronchopulmonary aspergillosis (ABPA) may include:
Wheezing
Coughing
Fever (in rare cases)
Aspergilloma
“fungus ball”
Symptoms of invasive aspergillosis may include:
Fever
Chest pain
Shortness of breath
Other symptoms may develop if the infection spreads beyond the lungs. When invasive aspergillosis spreads outside of the lungs, it can cause symptoms in almost any organ.

30. Aspergillosis
ABPA can affect people who are otherwise healthy, but it is most common in people with asthma or cystic fibrosis
Invasive aspergillosis generally affects people who have weakened immune systems
Those who have had a bone marrow transplant or solid organ transplant, people who are taking high doses of corticosteroids, and people who are getting chemotherapy for cancer.
Healthcare providers consider symptoms
Further testing may include imaging tests such as x-rays or CT scans of the lungs, biopsies of affected tissue and samples may be analyzed for evidence of the fungus
Requires treatment with antifungal medication prescribed by a doctor
In the more invasive form, the fungus produces a necrotic
pneumonia and disseminates to the brain