BIOM5003Z Alternative Case Study Assessment Brief | University of Plymouth

About This Brief

During the COVID-19 pandemic, June Bates, a 20-year-old university student, visited her family for Christmas in 2020. While attending university, she lived in shared accommodation with other students, none of whom had any symptoms of COVID-19 when she left for home. However, three days after her arrival, one of her housemates informed her that they had developed a mild, cold-like illness.

June remained asymptomatic, but unfortunately, the rest of her family experienced varying degrees of illness. Three days after her arrival, both of her parents developed flu-like symptoms, including coughing and fever, and subsequently tested positive for SARS-CoV-2 via PCR. Her mother, Mrs. Bates, recovered after eight days, but her father, Mr. Bates—a previously healthy 64-year-old man—experienced a more severe progression. Nine days after the onset of his symptoms, he developed dyspnoea, a high fever, and persistent coughing. He was hospitalized, where his blood oxygen saturation was found to be 90%, and laboratory tests revealed elevated serum levels of C-reactive protein (CRP, 18.7 mg/dL) and lactate dehydrogenase (LDH, 608 U/L). Chest computed tomography (CT) showed bilateral multiple ground-glass opacities, indicative of viral pneumonia. He was administered 250 mg of methylprednisolone daily for three days. However, his respiratory condition deteriorated, leading to intubation on the fourth day of hospitalization. By this point, his throat swab for SARS-CoV-2 PCR had turned negative. His condition remained unchanged for four weeks but gradually improved afterward.

June’s two younger siblings, who also lived in the Bates household, exhibited different responses to the infection. Jack, her 15-year-old brother, developed a mild flu-like illness but recovered within a few days. In contrast, her 17-year-old sister, Muriel—who had a history of severe influenza infections—experienced a more severe course. She had persistent fever and coughing and was diagnosed with viral pneumonia. She was hospitalized and required oxygen inhalation, though she did not need intubation. Muriel’s recovery took eight weeks from the onset of her illness.

Instructions

Based on the case study, analyze and respond to the following questions:

1. Innate immune responses play a crucial role in the pathogenesis of SARS-CoV-2 infection.

• Describe and evaluate the innate immune sensors involved in recognizing SARS-CoV-2, their ligands, and the downstream immune mechanisms they activate.
• Identify the various host cells that participate in SARS-CoV-2-triggered immune responses.

2. The Bates family members experienced significantly different disease outcomes.

• Provide potential explanations and mechanisms for the variability in disease severity among them.