All of the following infections are transmitted through exposure to infectious blood, except:

Tripura CHO - 2021

Applied Microbiology & Infection control

Easy

Appeared in: Tripura CHO - 2021

Explanation

Hepatitis E virus (HEV) is the correct answer as it is the exception to the group.
Its primary mode of transmission is the fecal-oral route, most commonly through the ingestion of water contaminated with fecal matter.
Unlike the other options, HEV is not classified as a bloodborne pathogen, although rare transmission through blood products has been documented.
Outbreaks are often linked to poor sanitation and contaminated water supplies, particularly after heavy rainfall or flooding in endemic areas.

Option A: Hepatitis B (HBV) is incorrect because it is a well-known bloodborne pathogen. It is transmitted through percutaneous or mucosal exposure to infected blood and various body fluids, such as semen and saliva.
Option B: Hepatitis C (HCV) is incorrect because it is primarily transmitted through parenteral (blood) exposure. The most common modes are sharing contaminated needles among injection drug users and, historically, through unscreened blood transfusions.
Option C: HIV (Human Immunodeficiency Virus) is incorrect because it is a bloodborne virus. It is transmitted through direct contact with certain infected body fluids, most commonly blood, semen, vaginal fluids, and breast milk.

Clinical Relevance

Nursing practice connection: Knowing Modes of transmission for infectious diseases helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding transmission routes is critical for applying the correct infection control precautions. Bloodborne pathogens require Standard Precautions for all patients, while fecal-oral pathogens may require Contact Precautions if the patient is incontinent.
A nurse sustaining a needlestick injury must be evaluated for exposure to HBV, HCV, and HIV. Post-exposure prophylaxis (PEP) protocols target these specific bloodborne viruses.
Hepatitis E can be particularly severe in pregnant women, especially during the third trimester, leading to a high risk of acute liver failure and mortality. This is a critical consideration in obstetric nursing.

How to Approach the Question

First, identify the keyword 'except'. This signals that you must find the option that does not fit the condition described in the stem.
The condition given is 'transmitted through exposure to infectious blood'. This means you are looking for an infection that is NOT bloodborne.
Systematically evaluate each option's primary mode of transmission.
Recall that Hepatitis B, Hepatitis C, and HIV are classic examples of bloodborne pathogens taught in nursing curricula.
Identify Hepatitis E as the outlier. Its transmission route is enteric (fecal-oral), similar to Hepatitis A.
Conclude that Hepatitis E is the correct answer because it is the exception to the rule of bloodborne transmission presented by the other options.

Concept Tested & Keywords

Concept Tested: Modes of transmission for infectious diseases
Stem keywords: infections, transmitted, infectious blood
Lead-in keywords: except
Negative lead-in flag: The question asks for the exception among the given options.

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