Use the following information to answer questions 8–10.


A Maryland woman was hospitalized with dehydration. V. cholerae and Plesiomonas shigelloides were isolated from the patient, who had neither traveled outside the United States nor eaten raw shellfish during the preceding month. The patient had attended a party before hospitalization. Two other people at the party had acute diarrheal illness and elevated levels of serum antibodies against Vibrio. Everyone at the party ate crabs and rice pudding with coconut milk. Crabs left over from this party were served at a second party. One of the people at the second party had onset of mild diarrhea; specimens from of these people were negative for vibriocidal antibodies.


This is an example of
a. vehicle transmission.
b. airborne transmission.
c. transmission by fomites.
d. direct contact transmission.
e. healthcare-associated transmission.

Verified step by step guidance

1. Identify the key details in the scenario: the patient was hospitalized with dehydration, V. cholerae and Plesiomonas shigelloides were isolated, and there was no travel or raw shellfish consumption.
2. Note that the patient attended a party where others also experienced acute diarrheal illness and had elevated serum antibodies against Vibrio.
3. Consider the food items consumed at the party: crabs and rice pudding with coconut milk, and note that crabs were served again at a second party.
4. Recognize that one person at the second party experienced mild diarrhea, but specimens were negative for vibriocidal antibodies.
5. Analyze the mode of transmission: since the illness was linked to food consumed at the party, this suggests vehicle transmission, where the pathogen is transmitted through a medium such as food or water.

Key Concepts

Transmission Routes

Understanding the different routes of disease transmission is crucial in microbiology. Transmission can occur through various means, including vehicle transmission (via contaminated food or water), airborne transmission (through respiratory droplets), direct contact (person-to-person), and fomite transmission (via contaminated surfaces). In this case, the consumption of crabs at the party suggests vehicle transmission, as the food may have been contaminated with pathogens.

Vibrio cholerae

Vibrio cholerae is a bacterium that causes cholera, characterized by severe diarrhea and dehydration. It is typically transmitted through contaminated water or food, particularly seafood. In the context of the question, the isolation of V. cholerae from the patient indicates a potential link to the food consumed at the party, highlighting the importance of food safety in preventing outbreaks.

Epidemiological Investigation

Epidemiological investigation involves studying the patterns, causes, and effects of health and disease conditions in defined populations. In this scenario, the investigation focuses on the common exposure of individuals at the party to crabs, which may have led to the transmission of V. cholerae. Identifying such links is essential for controlling outbreaks and implementing public health measures.