UN volunteers have arrived in Nigeria to assist the locals in aftermath of earthquakes. What drug should they prescribe for individual chemoprophylaxis of malaria?

Correct Answer: D

Rationale: The correct answer is D: Primaquine. Primaquine is used for individual chemoprophylaxis of malaria caused by Plasmodium vivax and Plasmodium ovale. It is effective in preventing the relapse of these malaria species by eliminating the liver forms of the parasites. Chingamin (A) is not a commonly used drug for malaria prophylaxis. Pyrantel (B) is an anthelmintic drug used for treating parasitic worm infections, not malaria. Pyrimethamine (Chloridinum) (C) is primarily used in combination with sulfadoxine for treating uncomplicated malaria, not for chemoprophylaxis.

Correct Answer: B

Rationale: Answer B, Infectious mononucleosis, is not caused by enteroviruses. Infectious mononucleosis is primarily caused by the Epstein-Barr virus, a member of the herpesvirus family, not by enteroviruses. Enteroviruses are known to cause diseases such as myocarditis, herpangina, and Boston exanthema. Therefore, B is the correct answer. Myocarditis, herpangina, and Boston exanthema can all be caused by enteroviruses, making choices A, C, and D incorrect, respectively.

Correct Answer: B

Rationale: The correct answer is B: microvilli. Pili are hair-like structures found on the surface of some bacteria, while microvilli are microscopic cellular projections that increase surface area for absorption in cells like intestinal cells. Pili are involved in bacterial adhesion, while microvilli are important for nutrient absorption. Therefore, the correct answer is B. Incorrect choices: A: Fimbriae are short, thin appendages found on the surface of some bacteria, mainly used for adhesion. C: Cilia are hair-like structures found on the surface of some eukaryotic cells, often involved in movement or sensory functions. D: Flagella are long, whip-like appendages used for bacterial motility.

Correct Answer: A

Rationale: The correct answer is A: Motility. Native microscopic slides are ideal for observing motility because they allow for the observation of living microorganisms in their natural state. By observing the movement of microorganisms on a native slide, one can assess their motility characteristics accurately. Choice B (Division) is incorrect because native slides may not provide the ideal conditions for observing cell division, as it may be difficult to capture the exact moment of division in a live organism. Choice C (Presence of capsules) is also incorrect because observing capsules usually requires specific staining techniques that may not be suitable for native slides. Choice D (None of the above) is incorrect as native slides are indeed beneficial for observing motility.

Correct Answer: A

Rationale: The correct answer is A: Rotavirus. Rotavirus is a member of the Reoviridae family known for causing diarrhea in infants. It infects the lining of the small intestine, leading to symptoms like vomiting and watery diarrhea. Rationale: 1. Rotavirus is specifically known for causing diarrhea in infants. 2. Reoviruses are a family of viruses to which rotavirus belongs. 3. Congovirus (B), Hepadnavirus (C), and Picornavirus (D) do not belong to the Reoviridae family and are not associated with causing diarrhea in infants. In summary, choice A is correct as it aligns with the characteristics of the given family of viruses and their associated symptoms, while choices B, C, and D are incorrect as they do not fit these criteria.

Correct Answer: A

Rationale: The correct answer is A: Clostridium perfringens. This bacterium is an anaerobic, Gram-positive rod that forms terminal spores and produces gas. It is commonly associated with wound infections and gas gangrene. Clostridium botulinum causes botulism and does not typically present with gas production. Bacillus anthracis is an aerobic, Gram-positive spore-forming bacterium causing anthrax. Clostridium tetani causes tetanus and does not produce gas. Thus, based on the characteristics described in the question, Clostridium perfringens is the most likely causative agent.

Correct Answer: A

Rationale: The correct answer is A: BCG vaccination. The Mantoux test is used to detect tuberculosis infection. A negative reaction means the child is not infected. BCG vaccination is recommended for individuals without prior TB infection to prevent severe forms of the disease. Antitoxin and rabies vaccinations are not related to TB and are not indicated in this scenario. Repeating the Mantoux test is unnecessary since a negative result indicates absence of TB infection.

Correct Answer: B

Rationale: The correct answer is B: septicemia. Septicemia specifically refers to the presence of bacteria in the bloodstream, leading to a systemic inflammatory response. Bacteremia (choice A) is simply the presence of bacteria in the blood without the systemic inflammatory response. Shock (choice C) is a state of circulatory collapse, often seen in severe septicemia. Bloodborne infection (choice D) is a general term for infections transmitted through the blood but does not specifically refer to the condition of bacterial multiplication causing toxicity.

Correct Answer: A

Rationale: The correct answer is A: Oxidation. Phase I reactions in biotransformation involve introducing or unmasking functional groups through oxidation, reduction, or hydrolysis. Oxidation reactions typically involve the addition of an oxygen atom or removal of hydrogen atoms, making them common phase I reactions. In this process, enzymes like cytochrome P450 play a crucial role in catalyzing the oxidation reactions. Conjugation (B), acetylation (C), and glucuronidation (D) are all examples of phase II reactions, which involve the conjugation of the drug or metabolite with endogenous compounds to increase water solubility for excretion. These reactions typically follow phase I reactions and are not classified as phase I reactions in biotransformation.