A 47-year-old patient came to see a doctor on the 7th day of disease. The disease developed very fast: after the chill body temperature rose to 40oC and lasted up to 7 hours, then dropped abruptly, which caused profuse sweat. There were three such attacks occur in once in two days. Two days ago the patient arrived from Africa. Objectively: pale skin, subicteric sclera, significantly enlarged liver and spleen. What is the cause of fever attacks in this disease?

Correct Answer: A

Rationale: The correct answer is A: Erythrocytic schizogony. In this case, the patient most likely has malaria, specifically caused by Plasmodium falciparum. The fever attacks every 2 days (tertian fever) are characteristic of P. falciparum infection. The cycle of erythrocytic schizogony in P. falciparum is around 48 hours, leading to the recurring fever pattern. Choices B, C, and D are incorrect as tissue schizogony does not cause the characteristic fever pattern, exotoxins are not typically involved in malaria fever, and gametocytes do not directly cause fever attacks.

Correct Answer: C

Rationale: Rationale: 1. Presence of gram-negative bacilli suggests Enterobacteriaceae family, which includes E. coli. 2. Green soluble pigment indicates pyocyanin production, characteristic of E. coli. 3. E. coli is the most common cause of acute cystitis due to its ability to colonize the urinary tract. Summary: A: Pseudomonas aeruginosa is not typically associated with acute cystitis and does not produce mucous colonies. B: Klebsiella pneumoniae may cause UTIs, but does not produce green pigment and is less common than E. coli. D: Salmonella enteritidis is associated with gastrointestinal infections, not cystitis.

Correct Answer: A

Rationale: The correct answer is A: Metronidazole. Metronidazole is a synthetic antiprotozoan drug with high activity against Helicobacter pylori, a bacterium that can cause wound infections. Metronidazole specifically targets anaerobic bacteria like H. pylori, making it effective in preventing wound infections. Incorrect choices: B: Doxycycline hydrochloride - Doxycycline is primarily used for bacterial infections, not protozoan infections like H. pylori. C: Chingamin - Chingamin is not a commonly used drug for treating H. pylori infections or preventing wound infections. D: Acyclovir - Acyclovir is an antiviral drug used to treat herpes infections, not bacterial or protozoan infections like H. pylori.

Correct Answer: A

Rationale: The correct answer is A: Itraconazole. Itraconazole is an antifungal medication commonly used to treat candidosis. It works by inhibiting the synthesis of ergosterol, a key component of fungal cell membranes. This action disrupts the integrity of the fungal cell membrane, leading to cell death. Griseofulvin (B) is primarily used to treat fungal infections of the skin and nails, not mucous membranes. Nitrofungin (C) is not commonly used for candidosis treatment. Amphotericin (D) is a potent antifungal medication but is typically reserved for severe or systemic fungal infections due to its potential side effects.

Correct Answer: D

Rationale: Step-by-step rationale: 1. The study results indicate water contamination. 2. Contaminated water poses health risks. 3. Therefore, the correct interpretation is that water is contaminated. Summary: - Choice A is incorrect as safety is not confirmed. - Choice B is too mild given the severity of contamination. - Choice C is also incorrect, as it does not accurately reflect the study findings.