Hepatozoon

Question 1

What are the species of Hepatozoon: (4)

Answer 1

• Hepatozoon canis = H: dogs (in europe) V: Rhipicephalus sanguineus, Ixodes spp.
• Hepatozoon americanum = H: dogs (in america) V: Amblyoma maculatum
• Hepatozoon felis = H: cats V: Rhipicephalus sanguineus
• Hepatozoon aegypti = H: snake V: mosquitos

Question 2

What is the Intermediate host of Hepatozoon:

Answer 2

Canine and feline - Asexual reproduction

Question 3

What is the definitive host of Hepatozoon:

Answer 3

Ticks (vector) - Sexual reproduction, sporogony happens

Question 4

What is the transmission of Hepatozoon:

Answer 4

Oral infection - have to ingest an infected tick

Question 5

What are the types of Hepatozoon:

Answer 5

• Gametocytes = in circulating Leukocytes
• Tissue “Cysts” = in muscle

Question 6

Describe the Life cycle of Hepatozoon:

Answer 6

Intermediate host:
1. Infected tick is ingested by the dog/cat
2. Sporozoites are released in the dog/cat GIT
3. Sporozoites penetrate the intestinal wall, entering blood circulation spreading into various organs (lymph nodes, liver, spleen, bone marrow, skeletal muscle) forming Merozoites
4. Merozoites form a primary Meronts
5. The Meront becomes either Macromeront that can re-infect cells or from elongated Micromerozoites within “wheel spoke” Meront
6. Micromerozoites then invade neutrophils where they become Gamot (can also transmit intrauterine to puppies/kittens)

Final host:
1. Tick ingests blood with infected Neutrophils
2. Gamogony forms a Zygote
3. Forming into Mature Oocyst with Sporocysts containing Sporozoites