Exam Master Infectious Disease 2024 Questions With Complete Answers Graded A+

Case A 23-year-old man presents with a 2-day history of watery nasal discharge, malaise, sneezing, and nasal congestion. On examination, you notice inflammation of the nasal mucosa. Pulse is 80/min. BP is 130/80 mm Hg, and temperature is 98.8 °F. Question What investigations will you order to establish the diagnosis? - CORRECT ANSWER Correct answer: No specific diagnostic workup needed Explanation The correct answer is no specific diagnostic workup needed. This patient is suffering from viral rhinitis (common cold). No specific workup beyond a clinical diagnosis is necessary for an otherwise healthy patient1. Nasal swab with polymerase chain reaction PCR can help establish a specific viral etiology, if needed. Complete blood count may show increased total leukocyte count. Viral serology establishes a specific viral etiology. X-rays may be positive in cases of sinus involvement. These investigations are not done routinely to establish a diagnosis, but may be necessary in specific clinical scenarios, such as in patients who are immunocompromised. Case An 18-month-old infant presents with a 5-day history of fever of 104°F. On physical examination, you note a mildly lethargic and irritable infant. There are no other clinically significant findings. You prescribe acetaminophen (Children's Tylenol) and tell the mother to monitor the infant's fever for the next few days; if the fever goes down, everything should be fine. The mother calls the next day and says that the fever has stopped, but a rash has developed and she is concerned. The infant examination reveals a diffuse, fine, maculopapular rash. Presently, the child does not appear ill. Question What is the most likely diagnosis? - CORRECT ANSWER Correct answer: Roseola Explanation The clinical picture is suggestive of roseola. Roseola is a benign illness in humans caused by the human herpesvirus 6 or 7. It is the major cause of acute febrile illness in young children. The most prominent feature is a fever lasting up to 8 days, the fever often exceeding 39.5°C (103.1°F). After the fever subsides, a rose-pink maculopapular rash appears. Rubella appears as a maculopapular rash beginning on the face and spreading to the entire body; it disappears by the fourth day after prodrome of low-grade fever, ocular pain, sore throat, and myalgias. Rubeola consists of the prodrome of fever, cough, conjunctivitis, and coryza. The rash appears as maculopapular, spreading down from the face and hairline to the trunk over 3 days, then becoming confluent. Erythema infectiosum rash appears as raised, fiery-red maculopapular lesions on the cheeks that give a "slapped-cheek" appearance. Varicella (chickenpox) rash appears as widely scattered red macules and papules concentrated on the trunk and face, progressing to vesicles and pustules and followed by crusting of the lesions. Case A 24-year-old man with a past medical history of HIV positive status for 2 years presents due to an ongoing chronic cough that he has had for the past 8 months. He admits to a mild fever that comes and goes during that same time period. A 5-pound unintentional weight loss is also discovered since his last visit to your office, which was approximately 9 months ago. He states he has noted an increased amount of breathlessness with just simple activities, which was never bothersome before the cough began. The patient denies smoking, and his TB test is negative. Question What is the most likely organism causing this patient's signs and symptoms? - CORRECT ANSWER Correct answer: Mycobacterium avium complex Explanation The patient being described in the above scenario is more than likely suffering from a pulmonary infection secondary to Mycobacterium avium complex (MAC). This type of infection is almost indistinguishable from tuberculosis, but causes a chronic, slowly progressive pulmonary infection in both immunocompromised and immunocompetent patients. Symptoms, when they present, are less severe and more chronic than a Mycobacterium tuberculosis infection. Symptoms most commonly seen include the following (as well as how often they are found): cough (91%), sputum production (85%), weight loss (53%), breathlessness (51%), chest pain (34%), hemoptysis (32%), and fever or night sweats (17%). Mycobacterium lepraeis the organism that leads to Hansen disease, otherwise known as leprosy. This disease state is rarely seen in the United States but is endemic in tropical and subtropical Asia, Africa, and Central/South America. Signs and symptoms are pale macular/nodular and erythematous skin lesions, as well as superficial nerve thickening, associated anesthesia, and motor abnormalities. Bilateral ulnar neuropathy is highly suggestive of this diagnosis. This is inconsistent with our patient. Mycobacterium haemophilum, Mycobacterium bovis, and Mycobacterium chelonae are all potential causes of lymphadenitis, also known as scrofula. These organisms are much more prevalent in Northern Europe and signs are not consistent with the patient scenario above. Case Your 25-year-old patient is 31 weeks pregnant. Her third-trimester chlamydia screening comes back positive. Question How do you proceed to counsel the patient? - CORRECT ANSWER Correct answer: Take azithromycin 1 gm PO x 1D, then perform a test-of-cure at the Group Beta strep screening. Explanation Azithromycin 1 g po x 1 is proven safe and effective in treating chlamydia in pregnancy. A test-of-cure (TOC) is recommended for pregnant women 3-4 weeks after treatment is completed. Group Beta strep cultures are obtained at 35-37 weeks gestation, which is around the same time a TOC should be obtained for this patient. Doxycycline is not recommended in pregnancy. Abstinence from sexual intercourse is recommended for 7 days after treatment is completed. Erythromycin base 50 mg/kg/day orally divided into 4 doses daily for 14 days is the treatment for ophthalmia neonatorum. The CDC recommends sex partners be evaluated, tested, and treated. Question What is the most accurate statement regarding histoplasmosis? - CORRECT ANSWER Correct answer: Itraconazole, amphotericin B, ketaconazole, and fluconazole are all reasonable choices for therapy