Question

A male student that attends a 4 year College majoring in Arts and music felt sick for a day with diarrhea he took some medication and felt fine. 8 days later he had a second round of diarrhea this time it was much worse and lasted most of the day. Again with somewhat more medication he was fine. 5 days later he had a 3rd round of diarrhea that was much worse and included vomiting. He was bed ridden the next day his symptoms continued with fever. 1. What disease does he have? Name the causative agent. 2. How did he become infected with this microbe? Explain the pathogenesis of this disease. 3. What is the virulence factor and how would you treat this disease? 4. How would the immune system deal with this case and why? 5. Why Doctors could only treat the symptoms before and not the disease and why death may result from it?( microbiology)

Answer 1

Please find the answers below:

Answer 1: According to the symptoms of the patient, it is highly likely that the repeated appearance of diarrhoea and vomiting are caused due to Shigella infection and hence the patient is suffering from shigellosis. The failure of treatment success even after taking initial course of antibiotics further indicate shigellosis infection caused by Shigella dysenteriae.

Answer 2: Shigellosis generally is transmitted through infected contaminated food and water and thus transmitted via the fecal and oral routes. This is why this disease management demands extreme sanitation.

As a pathogenesis, this disease causes abrupt and severe diarrhoea along with vomiting and fever. Failure of retention of water and nutrients lead to further deterioration of the health and person feels dizziness and weakness. Bloody-faeces are often seen in extreme cases of infection.

Answer 3: The bacterial coat cover or proteinaceous extension represent to be the primary virulence factor. These proteins are able to directly invade the epithelial cells of the intestine thus penetrating them and inserting the bacteria directly into the walls of intestine. Although some antibiotics are used against this infection, vaccines are not available as of now and hence, frequent rehydration, extreme sanitation and patient-specific combinatorial antibiotic therapies are given.

Answer 4: Since the bacteria immediately releases enterotoxins in the body, both humoral and cell-mediated immune responses are activated at once. These immune branches not only try to destroy the enterotoxins by their macrophage-mediated destruction but also tend to attack the bacteria by generating antibodies against it and killing by NK cells and other phagocytic cells.

Answer 5: Since no exact medicine/vaccine is currently available against this disease, doctors and medical experts can only cure for the symptoms produced by this disease. Hence, extreme cases of infection may result into death.