Parasitic Infections
The following parasitic infections are predominantly ectoparasites EXCEPT:
Parasitic Infections
- Parasites are organisms that live in or on a human host and cause harm. They include protozoa (single-celled) and helminths (worms).
- Malaria — extra detail because it is important:
- Malaria is transmitted by the bite of a female Anopheles mosquito. The Plasmodium parasite enters the red blood cells and destroys them, causing the characteristic fever. There are four main species: - Plasmodium falciparum — most dangerous
- Prevention of malaria: - Insecticide-treated bed nets - Indoor residual spraying - Prophylactic drugs for travellers (Doxycycline, Atovaquone-Proguanil)
Read this in MASTER PHARMACOLOGY NOTES
What our notes say
- The following parasitic infections are predominantly ectoparasites EXCEPT: (Paediatrics Senior Clerkship end of 2nd semester exam: 4 October 2021, 50 MCQs)
- Parasitic infections are caused by organisms that live on or in a host organism and derive nourishment at the host's expense. (Common fungal and parasitic infections)
- Enterobius vermicularis (pinworm) is the most common parasitic infection worldwide, especially among children. (Pinworm (Enterobius vermicularis))
- Schistosomiasis: Praziquantel to treat the parasitic infection. (Pulmonary hypertension and cor pulmonale)
- *Upon completion of this module, you will be able to approach common fungal and parasitic infections encountered in Kenyan clinical practice. (Common fungal and parasitic infections)
- | Gastro‑intestinal | Acute gastroenteritis, chronic diarrhoea (e.g., from parasitic infection) | Direct fluid loss, electrolyte depletion | (Fluid balance)
Study material on Parasitic Infections
- Common fungal and parasitic infections
- Weekly Year 2: Cellular Immunology Exam - March 27, 2026 (Section A: MCQs)
Practice questions on Parasitic Infections
A 40-year-old man has a peripheral blood eosinophil count of 4500/microliter persisting for 6 months. He has no parasitic infection, no allergic disease, and no drug exposure. Bone marrow shows eosinophilic hyperplasia. FISH reveals FIP1L1-PDGFRA fusion gene. Most likely diagnosis?
- Reactive eosinophilia from parasitic infection
- Hypereosinophilic syndrome
- Eosinophilic leukemia with PDGFRA rearrangement
- Allergic bronchopulmonary aspergillosis
Answer: C. Persistent marked eosinophilia + FIP1L1-PDGFRA fusion gene = eosinophilic leukemia. This is a clonal myeloid neoplasm driven by a tyrosine kinase fusion. Unlike reactive eosinophilia, it has a primary clonal driver and responds to imatinib.
Which blood cell type is primarily responsible for defence against parasitic infections?
- Lymphocytes
- Eosinophils
- Monocytes
- Neutrophils
Answer: B. Eosinophils contain cytotoxic granule proteins (e.g., major basic protein, eosinophil cationic protein) specifically effective against helminths and other parasites.
Which white blood cell is the primary mediator in parasitic infections and allergic reactions?
- Neutrophil
- Basophil
- Eosinophil
- Monocyte
Answer: C. Eosinophils degranulate against parasites and release mediators in allergic responses; eosinophilia is a hallmark of both conditions.
Parasitic infections (trichinosis, schistosomiasis, strongyloidiasis) cause elevated numbers of?
- Basophils
- Eosinophils
- Macrophages
- Neutrophils
Answer: B. Tissue-invasive parasites trigger Th2 immune responses and IgE production, driving eosinophilia.
Which blood cell type is primarily responsible for defence against parasitic infections and also plays a role in allergic reactions?
- Neutrophils
- Lymphocytes
- Monocytes
- Eosinophils
Answer: D. Eosinophils are granulocytes that are particularly effective against parasitic infections and release mediators that contribute to allergic inflammation.
Which of the following cell types is primarily involved in host defense against parasitic infections and allergic reactions?
- Neutrophils
- Macrophages
- Eosinophils
- Dendritic cells
Answer: C. Eosinophils are granulocytes that play a key role in defense against parasitic helminths (worms) and are also heavily involved in allergic and asthmatic responses.