Question

Your committee’s charge is to investigate a concern presented by the state health department, which maintains registries for most infectious diseases. Review of these registries revealed that over the past five years, 16 cases of acute hepatitis virus infection had a commonality: 16 patients had visited the same hospital based medical practice, South Suburban Hospital, before the onset of the infection. The state health department conducted an investigation, consisting of the collection of blood samples from healthcare personnel coupled with a series of comprehensive interviews. Results of the investigation indicated the following: none of the healthcare personnel had a history of acute hepatitis or HBV immunizations. The state health department conducted an investigation, consisting of the collection of blood samples from healthcare personnel coupled with a series of comprehensive interviews. Results of the investigation indicated the following: none of the healthcare personnel had a history of acute hepatitis or HBV immunization, and to physician dermatologist had a negative HBV surface antigen test but positive HBV surface antibody tests, which indicated that the physicians had been exposed to HBV. Further investigation revealed that these two physicians had seen 15,000 patients over the five-year study. The majority of these patients were white, female, and over the age of 50 years.

Based on this study what is the incidence rate for HBV?

Index case. Due to the lack of highly detailed data, it may not be possible to identify the index case with certainty. Still, there is a very limited number of possibilities. Describe the possibilities, and what implications come with each being identified as the index case.

What is the hospital’s plan to ensure the future outbreaks will not occur?

Before investigating the outbreak and searching for answers to the questions posted by the State Health Department, what preliminary question must be answered by your committee?

Answer 1

1. The incidence rate for any disease is represented by the formula :

=>Incidence Rate = (New Cases occurring over a period of time /population at risk during the same time * 100)

Here New Cases = 16 ; population at risk = 15000

Incidence rate = 16/15000 during 5 years = 0.1067 % in 5 years

or 16/(5*15000) = 0.002 in one year

2.

Describe the possibilities, and what implications come with each being identified as the index case.

With each one being identified as the index case the implications can be worrisome as the rate at which the infection spread occurs in a compounding rate. This disease is usually transmitted sexually and through syringe transmission. We can assume that each and every individual would have infected his/her partner, in some cases a multiple of them, and a high number of individuals would have been affected till now with the disease.

Index Case or more colloquial term "Patient Zero" can be identified using methodological studies in the field on epidemiology, usually, the patient zero is identified by tracking down all the possible cases ( infected patients). Here 16 of the patients have been identified as the possible cases but identifying them as the index cases can do more harm than good as it can have serious repercussions in the form of societal stigma and anger. While the analysis may be correct in identifying the patient zero but there is always a margin of error like in the case of the possible AIDS index case of Gaetan Dugas who was a flight attendant who was wrongly identified as the patient zero for bringing AIDS in the USA however studies done later denied the allegation but the damage to the reputation of the individual cannot be undone.

3.

What is the hospital’s plan to ensure the future outbreaks will not occur?

To ensure future outbreaks do not occur :

• Ensure contact tracing of all the possible cases.
• Regular checkup of health staff and other paramedic staff who may be at risk and susceptible to infectious diseases.
• Proper communication with authorities like CDC and the WHO to notify whenever an outbreak like situation may seem like a possibility to drive containment measures as soon as possible.
• Providing proper PPE(Personal Protection Equipment ) to the hospital staff.
• Strict adherence to social distancing among the patients and the hospital staff.

Before investigating the outbreak and searching for answers to the questions posted by the State Health Department, what preliminary question must be answered by your committee?

• What did the contact tracing results yield?
• How many patients could have been affected on the basis of the transmission rate.
• The origin of the virus ( if zoonotic ) then the possibilities of its jump to humans ( analysing various scenarios)