Review Question - QID 210530

A 5-year-old boy is brought to the pediatrician for anal pain. He and his mother immigrated to the United States from Trinidad and Tobago 3 months ago. The boy reports severe pain with defecation. He is frequently constipated and has approximately 1-2 bowel movements per week. He has seen blood on the toilet paper after wiping multiple times and sometimes feels a need to "push" his anus back inside. More recently, he has been unable to hold his bowel movements and has had 2 episodes of fecal incontinence. His temperature is 99°F (37.2°C), blood pressure is 110/70 mmHg, pulse is 82/min, and respirations are 18/min. On exam, his anus appears normal. However, when asked to strain slightly, a notable finding is shown in Figure A. This patient's condition is associated with which of the following infections?