Parasites and Fungal Infections

Flashcards covering vocabulary terms related to parasites and fungal infections

Parasitism

The activity of an organism that spends any portion of its life in direct contact with a host species at the expense of its host

Protozoa

Exist in all body compartments, intra-and extracellular, cause a spectrum of disease

Helminths (worms)

Multicellular, highly organised, complex life cycles

Ectoparasites

External to the body eg. Insect, arachnids

Trypomastigotes

One of the forms in the trypanozone life cycle that can swim using flagella

Giardia

Uptake and metabolism of bile induces malabsorption

Trophozoite

A form in the life cycle where the parasite is absorbing nutrients from the host

Microaerophilic

Somewhere between aerobic and anaerobic microorganisms need oxygen to survive, but cannot tolerate normal atmospheric levels

Bradyzoite

A stage of the life cycle when the parasite replicates very slowly and is enclosed in a cyst- like structure

Ascaris lumbricoides

Transmission by eggs in human faeces; migration of larvae results in allergic pneumonia; Gut pathology associated with numbers of parasites and nutrient competition

Hookworms

Skin penetrating larvae, stylets in buccal cavity to facilitate blood feeding, Skin invasion, Lung migration: haemorrhage and pneumonia, Gut: anaemia and protein loss

Filariasis

Long lived; require larval passage through insect vector; 4 major species

Wucheria bancrofti, brugia malayi

Lymphatic disease

Onchocerca volvulus, loa loa

Blindness

Fungi

Eukaryotic organisms

Yeasts

Single celled budding organisms, with/without hyphae

Moulds

Multicellular filamentous organisms with hyphae and fruiting structures

Body temperature

Warm temperatures prevents mould germinating

Candida infections (yeast)

Overgrowth of colonising flora, Usually in most warm areas

Dermatophyte infection (mould)

10% population infected, Utilize keratin as a nutrient source

Coccidiodes immitis

Pulmonary symptomatic 40%, Acute Valley Fever, Skin Rash, hemoptysis, empyema Skin ,bone and joints CNS meningitis

Histoplasma capsulatum

Primary respiratory infection, Asymptomatic to mild (90-95%), Flu-like illness (5-10%)

Blastomycosis

Dimorphic fungal infection, Symptomatic Flu-like symptoms, Pneumonia

Invasive Candida infection

Opportunistic pathogens - immunocompromised

Invasive Aspergillosis

Opportunistic pathogens -immunocompromised

Diagnosis of Aspergillosis

Galactomannan ELISA

Cryptococcus neoformans

Pigeon/avian excreta, World wide distribution

Cryptococcosis

Opportunistic pathogens -immunocompromised

Cryptococcus Capsule

Antiphagocytic & imunomodulatory

Pneumocystis jirovecii

Opportunistic pathogens -immunocompromised

Malaria

Plasmodium

Plasmodium

Eukaryotic protozoan transmitted through the bite of a female mosquito

Infection of plasmodium falciparum

The sporozoite is transmitted from the mosquito into the blood stream, eventually finding its way into a liver cell.

Treatment for malaria

Initial treatment should be as for falciparum malaria with quinine

Combination therapy for malaria

Drug of choice: artemisinin-based combination therapy (ACT)