Diagnostic Performance and Kinetics of Hepatitis E Viral RNA and IgM Antibody Test Positivity in a Genotype 1 Outbreak in South Sudan

Category	Detail
Condition	Hepatitis E virus (HEV) infection, genotype 1
Key Mechanisms	Fecal contamination of drinking water leading to HEV genotype 1 outbreaks; viral RNA detectable by PCR; IgM antibodies detectable by ELISA and rapid diagnostic tests
Target Population	Suspected acute jaundice syndrome cases in outbreak settings, including displaced persons in South Sudan
Care Setting	Health facilities in outbreak and low-resource settings with limited laboratory infrastructure

PCR, IgM ELISA, and IgM rapid diagnostic tests (RDTs) were evaluated during a HEV genotype 1 outbreak in South Sudan.
Within 30 days of jaundice onset, test sensitivities were 73% for PCR, 86% for RDT, and 95% for ELISA; all tests showed high specificity (95-98%).
Median time to negative test was 19 days for PCR and 113 days for ELISA, indicating prolonged IgM antibody presence.

Use IgM ELISA as the most sensitive test within 30 days of jaundice onset for hepatitis E diagnosis.
Consider IgM RDTs as effective field diagnostics with sensitivity higher than PCR and specificity comparable to ELISA.
Recognize that PCR sensitivity declines rapidly after jaundice onset and may miss cases if care seeking is delayed.

Implement reactive vaccination campaigns early in outbreaks to maximize impact.
Use rapid diagnostic tests to facilitate timely surveillance and outbreak response in settings lacking laboratory infrastructure.

Monitor time from jaundice onset when interpreting diagnostic test results due to declining sensitivity over time.
Be aware that IgM antibodies can persist for over 3 months, potentially causing prolonged positive ELISA or RDT results.

Delays in care seeking can reduce diagnostic test sensitivity and delay outbreak confirmation.
Prolonged IgM positivity may lead to false-positive interpretations if timing of infection is unknown.

Suspected acute jaundice syndrome cases during HEV genotype 1 outbreak in displaced persons camp

Reactive vaccination with Hecolin was implemented; diagnostic test choice influences timely case identification and outbreak control.

Prioritize IgM ELISA or IgM RDT for hepatitis E diagnosis within 30 days of jaundice onset.
Use PCR primarily in early symptomatic phase due to rapid decline in viral RNA detectability.
In outbreak settings with limited lab capacity, deploy IgM RDTs to enable point-of-care diagnosis and accelerate public health response.
Interpret positive IgM antibody results cautiously beyond 3 months post-jaundice onset due to prolonged antibody presence.
Encourage early care seeking to improve diagnostic accuracy and outbreak management.

Clinical Scorecard: Evaluation of Diagnostic Accuracy and Dynamics of Hepatitis E Viral RNA and IgM Antibody Positivity During a Genotype 1 Outbreak in South Sudan