1 What disease is caused by Toxoplasma gondii?
Toxoplasmosis.
2How do humans most commonly get infected by Toxoplasma gondii?
By ingesting Toxoplasma cysts from the environment (cat feces, soil) or undercooked meat. Other routes include blood transfusion or transplacental transmission.
3What are the key risk groups for severe Toxoplasma gondii infection?
Immunosuppressed individuals (e.g., HIV+) and pregnant women.
4What is the classic triad of symptoms for a fetus infected with Toxoplasma gondii?
Chorioretinitis, hydrocephalus, and intracranial calcifications.
5What is the only known definitive host for Toxoplasma gondii?
Domestic cats and their relatives.
6What diagnostic methods are commonly used for detecting Toxoplasma gondii infection?
Serology (Toxoplasma IgG/IgM), direct observation of cysts in tissue, PCR of patient specimens.
7What organism causes Pneumocystis pneumonia (PCP)?
Pneumocystis jirovecii (formerly known as Pneumocystis carinii).
8Which populations are most at risk for Pneumocystis pneumonia (PCP)?
Immunosuppressed patients, particularly those with HIV/AIDS, and individuals on immunosuppressive therapy.
9How is Pneumocystis jirovecii typically transmitted?
Person-to-person through the air
10What are the typical clinical symptoms of Pneumocystis pneumonia (PCP)?
Difficulty breathing (dyspnea), nonproductive cough, fever, and bilateral infiltrates on a chest X-ray.
11What is the mortality rate for Naegleria fowleri infections in the United States?
97% mortality rate; only four out of 154 known infected individuals (1962-2021) have survived.
12 How does Naegleria fowleri typically enter the human body, and what disease does it cause?
It enters through the nose during aquatic activities and causes acute primary amebic meningoencephalitis (PAM).
13What diagnostic methods are used for detecting Naegleria fowleri?
Detection of trophozoites in CSF or brain tissue, PCR, antigen testing, and immunohistochemical staining.
14What is the most common route of exposure for Acanthamoeba infections leading to keratitis?
Using tap water to clean contact lenses or wearing contact lenses while swimming or showering.
15What is the laboratory diagnosis method for detecting Acanthamoeba in tissue samples?
Cysts and trophozoites can be found in tissue, and cultures can be performed on non-nutrient agar with E. coli.
16What are the four species of Plasmodium that cause malaria in humans?
Plasmodium vivax, Plasmodium malariae, Plasmodium ovale, and Plasmodium falciparum.
17What diagnostic stage of Toxoplasma gondii is observed in an unstained wet mount?
Sporulated (infective) oocyst.
18Which form of Toxoplasma gondii develops in human tissue after infection?
Bradyzoites, which form tissue cysts in neural and muscle tissues
19What are the main human infection routes for Toxoplasma gondii?
Ingestion of undercooked meat, exposure to contaminated cat feces, blood transfusion, organ transplantation, and transplacental transmission.
20What psychiatric disorders have been linked to Toxoplasma gondii infection?
Schizophrenia, bipolar disorder, and obsessive-compulsive disorder.
21What is the causative agent of Pneumocystis pneumonia (PCP)?
Pneumocystis jirovecii (formerly known as Pneumocystis carinii).
22What is the route of transmission for Pneumocystis jirovecii?
Person-to-person through airborne transmission.
23In which population is Pneumocystis jirovecii most prevalent?
Patients with HIV/AIDS and those on immunosuppressive therapy
24What staining method is used to visualize Pneumocystis jirovecii in tissue samples?
Silver stain.
25What is the infective stage of Naegleria fowleri in humans?
The trophozoite stage.
26What is the fatal disease caused by Naegleria fowleri and what part of the body does it affect?
Acute primary amebic meningoencephalitis (PAM), affecting the brain.
27What form of Acanthamoeba is most likely to infect the human cornea?
The trophozoite form, but cysts can also gain entry into the body.
28What is the common clinical presentation of Acanthamoeba keratitis?
Severe corneal infection, painful blindness, corneal ulceration, and scarring if untreated.
29What stage of Toxoplasma gondii is shown embedded in human muscle tissue?
Bradyzoite (tissue cyst).
30What stage of Toxoplasma gondii is observed in this unstained wet mount?
Sporulated oocyst, the infective stage.
31What stage of Naegleria fowleri is found in brain tissue and is the cause of PAM?
The trophozoite stage.
32What organism is visualized using silver stain in this image?
Pneumocystis jirovecii (causative agent of PCP).
33What stage of Acanthamoeba is shown in brain tissue, and what disease can it cause?
The cyst stage, which can cause granulomatous amebic encephalitis (GAE).
34What condition is likely associated with this image showing Acanthamoeba in eye tissue?
Acanthamoeba keratitis, a severe corneal infection often associated with contact lens use.