Please kill me - Parasitology

It is salivarian (anterior station) because the parasite develops in the front of the fly and is transmitted through the saliva during a bite. The vector is the Tsetse fly (Glossina spp.).

Why is T. brucei "salivarian" and what is its vector?

1. Procyclic trypomastigotes: Replicate in the fly midgut.

2. Epimastigotes: Form in the salivary glands.

3. Metacyclic trypomastigotes: The final infective stage found in the saliva.

Q: What are the stages of T. brucei in the Tsetse fly?

Gambiense: West/Central Africa; Chronic (slow progression over years).

Rhodesiense: East/Southern Africa; Acute (rapid progression over weeks/months).

Q: Compare T. b. gambiense vs. T. b. rhodesiense.

A: 1. Trypomastigotes: Ingested from host blood. 2. Epimastigotes: Replicate in the bug midgut. 3. Metacyclic Trypomastigotes: Found in the hindgut/rectum (infectious stage).

Q: What are the stages of T. cruzi in the Kissing Bug?

A:

Reservoirs: Raccoons, Opossums, Woodrats (and Dogs).

• Non-vector modes: 1. Blood transfusions/Organ transplants, 2. Congenital (mother to fetus), or 3. Oral (ingested contaminated food/juice).

Q: Name three reservoirs and two non-vector transmission modes.

A:

1. P. falciparum: The most virulent/deadly; causes sequestration (sticky RBCs).

2. P. vivax: Most widespread; characterized by relapses due to dormant liver stages (hypnozoites).

3. P. ovale: Similar to P. vivax; also produces hypnozoites and relapses.

4. P. malariae: Causes quartan fever (72-hour cycle); can stay as a low-level chronic infection for decades.

5. P. knowlesi: A zoonotic species from monkeys; has a very fast 24-hour cycle (quotidian fever).

Q: List the five major human malaria species and one distinguishing feature for each

Define Trophozoite vs. Cyst and the importance of encystation.

A:

• Trophozoite: The active, feeding, and reproductive stage inside the host.

• Cyst: The dormant, resistant stage with a protective wall.

• Encystation: the transition between stages

African sleeping Sickness Symptoms:

Intermediate fevers, significant swelling of the lymph nodes at the back of the neck.

• East African (T. b. rhodesiense): Progresses very quickly. Stage 2 symptoms can appear within weeks of the bite.

• West African (T. b. gambiense): A much slower, chronic progression. A person may be infected for months or even years before major neurological symptoms appear.