One summer, a group of tourists became ill after they all stayed at the same hotel in Greece. Epidemiologists conducted surveys among all the people who had stayed at that hotel during the two-and-a-half-week period in which people were reporting their illnesses. They did this in an attempt to determine the cause of the symptoms, which were primarily diarrhea and nausea.  They surveyed 239 people; 224 of them reported having been ill while they were still on vacation or shortly after their return. Their diarrheal symptoms lasted 10-15 days.  Seventy of the 224 people who reported illness were classified as having definite cases of gastrointestinal disease. A case was called “definite” when a pathogen could actually be recovered from their stool. Of these, the vast majority tested positive for one particular microorganism.  Microscopic analysis of the stool samples revealed the presence of small oval-shaped structures, with defined outer walls and two to four nuclei inside. Diagnostic tests ruled out Cryptosporidium as the pathogen. What is your diagnosis (what is the disease)?  What is the pathogen? What specific structures were seen in the stool? Epidemiologist interviewed the patients about their vacation activities and food intake to try to identify the environmental source of the infection. Only two types of food available in the dining room seemed to be associated with the illness: raw vegetables and salads. There was also a statistically significant relationship between illness and having consumed orange juice made from a mix (with hotel water).  So what was the likely source? What is the treatment for this disease?

Why is virulence expected to increase with vector or water-borne transmission, relative to direct transmission?  Using the concept of a “cost of virulence”, explain how vertical transmission or transmission in a hospital is thought to affect the level of virulence favored by natural selection?

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Which of the following are factors that can put hospitalized patients at risk of contracting nosocomial infections? Choose all that apply. Sick patients coming in to the hospital can bring pathogens with them Shared caretakers and equipment can transmit microbes between patients Patients may be exposed to antiseptic chemicals O An ill person has weakened immune function MacBook Air DD F9 F8 吕0 000 F7 F6 F5 F4 F3 & #3 $ 8 4 この

Which of the following statements is correct?   a. Serial interval is the length of time a person can transmit or shed an infectious agent   b. Contamination of the drinking water source of a community by infectious agent(s) will likely result in a continuous common source epidemic   c. It is not possible for people who have not shown symptoms of measles yet, to transmit measles infection   d. Mary Mallon was a chronic carrier of Vibrio cholerae

In 1969, a 16-year-old boy named Robert Rayford was admitted to a hospital in St. Louis, Missouri. He was weak, emaciated, rife with stubborn infections, and riddled with rare cancerous lesions known as Kaposi’s sarcoma, a skin disease found in elderly men of Mediterranean descent. Three months after he was admitted, he died of pneumonia. More than ten years later, similar cases were seen in states like New York and California. It was eventually discovered that young Robert Rayford actually had AIDS.   Using 2-3 pieces of evidence from the text, explain why Robert Rayford ended up dying from pneumonia.

Justinian’s Plague was the first appearance of Pasteurella pestis in Europe (6th century AD). Who was Justinian and what was the impact of this plague on his attempts to resurrect the old Roman Empire and, generally what was its impact on Europe at that time?

List 7 factors that would put a particular patient at a higher risk of contracting a nosocomial infection?  For each factor, explain why this group is at a higher risk.  If the reason is a drug, be sure to explain why the drug puts the person at a higher risk.

__________  _____________ are different types of practices that are necessary at the basic level of infection control   Question options: A) Standard Precautions B) Standard Safety C) Hand Washing D) None of the above

a.) The transmission of this disease can occur through an arthropod vector.        Group of answer choices Hepatitis A Rubella Plague H. influenzae b.) Consumption of contaminated food or water can lead to infection with:       Group of answer choices HIV Haemophilus influenza Enterococcus faecalis Hepatitis A c.) This pathogen is a common inhabitant of the human intestines and can cause urinary tract infections, particularly in patients       with urinary catheters. Group of answer choices Neisseria meningitidis Haemophilus influenza Enterococcus faecalis Mycobacterium leprae