Reference no: EM133335705

Prologue

On December 31th, 2019, the World Health Organization (WHO) was informed of 44 cases of an unknown respiratory disease in Hubei Province, China.

On 12 January 2020, China shared the genetic sequence of the novel coronavirus for countries to use in developing specific diagnostic kits. The story continues in South Korea in late January.

Part 1. A case of acute respiratory illness in South Korea

As of 21 January 2020, a total of 314 confirmed cases have been reported for novel coronavirus globally. Of the 314 cases reported, 309 cases were reported from China, two from Thailand, one from Japan and one from the Republic of Korea.

Between January 3rd and 14th, four more family members developed similar symptoms. The doctor who provided care to this family on January 6th developed respiratory symptoms on January 10th.

By January 19th, several nurses who worked in the ER and ICU of Hospital A reported ill with fever and one or more of these symptoms: cough, malaise, myalgia, and headache. They were told to isolate themselves at home and to wear masks. The local public health department was notified of this hospital cluster.

As a Field Epidemiologist placed with the local public health department, you are called in to assist.

Question 1a

Based on description of Part 1, is there an epidemic in Republic of Korea at this time point? Why or why not based on the definition of epidemic?

Question 1b

What source(s) of routine surveillance data (if available) could help confirm the existence of an epidemic in this investigation?

Question 1c

Who should be on the outbreak team (describe at least three persons and describe their roles) and what roles would they play?

Part 1. Collecting laboratory specimens

On January 12th, 2020, the WHO issued an alert about a new illness called COVID19; global surveillance activities were implemented. Based on the epidemiological and laboratory information available, the Korea Public Health department and clinicians identify the situation as a COVID19 outbreak.

Recognizing the need to coordinate laboratory-based surveillance with the epidemiologic investigation, the health department contacts the microbiologist at the provincial laboratory on January 20th to ensure parties keep one another updated.

The outbreak investigation team decide to look for other cases of COVID19 and adopt the outbreak case definition set by WHO:

Suspect case

A patient with acute respiratory illness (fever and at least one sign/symptom of respiratory disease, e.g., cough, shortness of breath), AND a history of travel to or residence in a location reporting community transmission of COVID19 disease during the14 days prior to symptom onset.
OR

A patient with any acute respiratory illness AND having been in contact with a confirmed or probable COVID19 case (see definition of contact) in the last 14 days prior to symptom onset;
OR

A patient with severe acute respiratory illness (fever and at least one sign/symptom of respiratory disease, e.g., cough, shortness of breath; AND requiring hospitalization) AND in the absence of an alternative diagnosis that fully explains the clinical presentation.

Probable case

A suspect case for whom testing for the COVID19 virus is inconclusive. Inconclusive being the result of the test reported by the laboratory.
OR

A suspect case for whom testing could not be performed for any reason.

Confirmed case

A person with laboratory confirmation of COVID19 infection, irrespective of clinical signs and symptoms.

As part of your hypothesis generation, you determine that you should interview one of the ill hospital staff members at home. You would collect the epidemiologic information and a nurse will collect specimens for laboratory testing. The nurse seeks your advice in determining what kind of questions she needs to ask and how.

Question 2a

What questions would you ask a person to determine whether it is a suspect case? Give an example of question and type of answer that would collect (binary, continuous, etc).

Question 2b

Outline benefits and limitations of using suspect case definition. Describe type of non-causal association that can arise.

Question 2c

Outline benefits and limitations of using confirmed case definition.

Question 2d

If your goal is to prevent the spread of COVID19, which case definition would you employ first and why?