Viral hemorrhagic fever after Africa trip. Virus family?

Correct Answer: A

Rationale: Step 1: Identify symptoms of viral hemorrhagic fever Step 2: Recall common viruses causing viral hemorrhagic fever Step 3: Understand characteristics of virus families Step 4: Filoviruses, like Ebola and Marburg, are known to cause viral hemorrhagic fevers due to their high pathogenicity. Step 5: Togaviruses, Bunyaviruses, and Flaviviruses are not typically associated with viral hemorrhagic fevers. Summary: Filovirus is the correct answer as it is a known cause of viral hemorrhagic fevers, while the other choices are not commonly associated with this condition.

Correct Answer: C

Rationale: The correct answer is C: Temporary water in jungles. Anopheles balabacensis is a species of mosquito known to breed in temporary water sources found in jungles. They typically lay their eggs in small, shallow pools of water that form after rainfalls. This choice is correct because it aligns with the known breeding habits of this particular mosquito species. A: Artificial containers - Incorrect. Anopheles balabacensis typically does not breed in artificial containers but prefers natural water sources. B: Drains - Incorrect. This species does not usually breed in drains but rather in natural water bodies. D: Rock pools - Incorrect. Anopheles balabacensis prefers temporary water in jungles over rock pools for breeding due to the specific environmental conditions required for egg-laying and larval development.

Correct Answer: D

Rationale: Step-by-step rationale for why answer D is correct: 1. An antigen is a substance that stimulates the production of antibodies. 2. Antigens can be proteins, carbohydrates, or other molecules that the immune system recognizes as foreign. 3. Antigens trigger the immune system to produce antibodies to neutralize or eliminate the foreign substance. 4. Therefore, the correct answer is D as it accurately describes the role of antigens in stimulating antibody production. Summary: A, B, and C are incorrect because: A: Antigens are not proteins themselves but can be recognized by antibodies. B: Antigens do not inhibit microorganism growth; they stimulate immune responses. C: Antigens do not directly stimulate antibody production; they trigger the immune system to produce antibodies in response to foreign substances.

Correct Answer: A

Rationale: The correct answer is A because rivaroxaban is a direct factor Xa inhibitor that works by inhibiting thrombin formation. Thrombin is a key enzyme in the blood coagulation pathway, and by inhibiting it, rivaroxaban prevents the formation of fibrin clots. Choices B and D are incorrect because rivaroxaban does not directly inhibit fibrinogen or work against vitamin K. Choice C is also incorrect as rivaroxaban does not actually "thin" the blood but rather prevents the formation of clots by inhibiting thrombin.

Correct Answer: B

Rationale: The correct answer is B because changes in dentition with cavities are not directly related to aging; they can occur at any age due to poor oral hygiene. Progressive hair loss, thickened/discolored nail beds, and dry skin are common age-related changes. Hair loss is linked to hormonal changes, nail bed changes may indicate poor circulation, and dry skin is a result of decreased oil production. Therefore, B is the correct answer as it does not specifically relate to age-related changes.