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Detection of poliovirus antigen by enzyme immunoassay
Abstract:
A solid-phase enzyme immunoassay (EIA) was developed for the detection of poliovirus antigen. Rabbit and guinea pig antisera for the assay were raised against purified poliovirus type 3/Fin (strain 3/Fin/K) isolated from a fecal specimen from a meningitis patient during an outbreak of poliomyelitis in Finland in 1984. The EIA was highly specific for poliovirus type 3, and it was about 30 times more sensitive for strain 3/Fin/K than for strain 3/Saukett used in the inactivated poliovirus vaccine. The sensitivity of the EIA was 2 to 5 ng of purified strain 3/Fin/K per ml, whereas disrupted viruses and soluble viral proteins were almost undetectable by the assay. Only 5 of 51 (10%) stool specimens containing poliovirus type 3/Fin detected by virus isolation were positive by the EIA. Quantitation by the EIA, using purified poliovirus 3/Fin/K as a standard, revealed that concentrations of poliovirus type 3 in undiluted fecal specimens of patients with natural poliovirus infection were only 50 ng/ml or less. In conclusion, owing to the small amount of poliovirus in feces, the EIA is not suitable for the diagnosis of poliovirus infections directly from clinical specimens, but it can be used to detect, type, and quantitate poliovirus antigen in infected cells.
Insights
A new enzyme immunoassay (EIA) detects poliovirus type 3 antigen with high specificity. However, low poliovirus levels in stool limit its diagnostic use for clinical specimens.
Area of Science:
- Virology
- Immunology
- Diagnostic Assay Development
Background:
- Poliomyelitis outbreaks necessitate sensitive diagnostic tools.
- Accurate detection and typing of poliovirus are crucial for public health surveillance.
Purpose of the Study:
- To develop and evaluate a solid-phase enzyme immunoassay (EIA) for poliovirus antigen detection.
- To assess the sensitivity and specificity of the EIA for poliovirus type 3.
Main Methods:
- Development of a solid-phase enzyme immunoassay (EIA).
- Generation of rabbit and guinea pig antisera against purified poliovirus type 3/Fin (strain 3/Fin/K).
- Testing EIA sensitivity and specificity using purified virus and clinical specimens.
Main Results:
- The EIA demonstrated high specificity for poliovirus type 3.
- The assay was significantly more sensitive to strain 3/Fin/K than to vaccine strain 3/Saukett.
- Sensitivity was 2-5 ng/ml for purified virus; disrupted viruses and soluble proteins were poorly detected.
- Only 10% of stool specimens positive for poliovirus type 3 by virus isolation were EIA-positive.
- Quantitation showed poliovirus type 3 concentrations in fecal specimens were 50 ng/ml or less.
Conclusions:
- The EIA is highly specific for poliovirus type 3 antigen.
- Low viral concentrations in clinical specimens limit the EIA's direct diagnostic utility for fecal samples.
- The EIA is suitable for detecting, typing, and quantifying poliovirus antigen in infected cells.