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Viral and serological kinetics in Zika virus-infected patients in South Korea

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ABSTRACT

Zika virus is a mosquito-borne flavivirus that causes clinical symptoms similar to those observed in dengue and chikungunya virus infections. The Korea Centers for Disease Control and Prevention initiated laboratory testing using a real-time reverse transcription-polymerase chain reaction in January 2016. More than 1,000 suspected cases of infection were tested and nine were confirmed as imported cases of Zika virus infection from January to July 2016. The travel destinations of the infected individuals were Brazil, Philippines, Viet Nam, Guatemala, Puerto Rico, and the Dominican Republic. Phylogenetic analysis based on the partial envelope gene indicated that the viruses belonged to the Asian genotype circulating in South America. We further investigated the duration for which the viral RNA and virus-specific antibodies were detectable after the symptom onset. After the day of symptom onset, Zika virus was detectable until 6 days in serum, 14 days in urine and saliva, and 58 days in semen. Immunoglobulin M against Zika virus was detected as early as 2 days after the symptom onset and was maintained at these levels until 41 days, whereas Immunoglobulin G was detectable from 8 days after the symptom onset and was maintained until 52 days. These findings would help diagnostic laboratories improve their testing programs for Zika virus infection.

No MeSH data available.


Related in: MedlinePlus

Profile of IgM and IgG responses to Zika virus infection in human serum. ELISA was performed using Anti-Zika Virus IgM/IgG ELISA kits (Euroimmun, Germany). a IgM ELISA response, b IgG ELISA response; the different symbols represent each patient. Interpretation of the results was based on the ratio of optical density of the patient serum over the value of the calibrator, according to the manufacturer’s instructions. Ratio < 0.8 indicates a negative result, 0.8 ≤ ratio < 1.1 indicates a borderline result, and ratio ≥ 1.1 indicates a positive result
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Fig3: Profile of IgM and IgG responses to Zika virus infection in human serum. ELISA was performed using Anti-Zika Virus IgM/IgG ELISA kits (Euroimmun, Germany). a IgM ELISA response, b IgG ELISA response; the different symbols represent each patient. Interpretation of the results was based on the ratio of optical density of the patient serum over the value of the calibrator, according to the manufacturer’s instructions. Ratio < 0.8 indicates a negative result, 0.8 ≤ ratio < 1.1 indicates a borderline result, and ratio ≥ 1.1 indicates a positive result

Mentions: The duration for which antibodies against Zika virus remain detectable in patient’s serum has not yet been established. The humoral immune response to Zika virus after infection was investigated using commercial kits (ELISA and gold rapid test). Anti-Zika Virus IgM and IgG ELISA kits from Euroimmun Inc. (Germany) were successfully used for detection of anti-Zika virus antibodies in 8 of the 9 (88.9%) patients (Fig. 3). However, no positive results were obtained using the Quantitative Human Zika Virus IgM ELISA kit (MyBioSource Inc., Lot E160512AI) and Zika virus IgM/IgG Ab Rapid Test (Biocan Diagnostics Inc., Lot B1815C021616). It could be concluded that the latter two kits were unacceptable for Zika virus testing and require improvement in terms of sensitivity; this was the first evaluation report for the two kits. Using the Euroimmun ELISA kit, IgM against Zika virus was detected as early as 2 days after the symptom onset and IgG was detected from 8 days after the symptom onset (Fig. 3). Of the seven patients whose serum samples were reactive to ELISA and for whom the days of symptom onset available, IgM was detected in acute-phase sera drawn from 4 (57.1%) patients, within 6 days post-onset. However, IgM was positive in all seven patients (100%) from 8 days post-onset. The IgM and IgG were maintained at detectable levels until 41 days and 52 days after the symptom onset, respectively. It is well known that IgM against flaviviruses, including dengue, West Nile, and Japanese encephalitis viruses, as indicated by ELISA, persist for up to several months and up to a year in the case IgG [12–14]. However, it was found that anti-Zika virus IgM antibody titer in patients 2, 3, and 6 fell to equivocal or negative levels at 42, 52, and 34 days post-onset (Fig. 3), respectively. The short duration of antibody detectability in those cases, as indicated by the Euroimmun ELISA, may be caused by the use of nonstructural protein 1 (NS 1) rather than E protein as a diagnostic marker. Further testing using other types of ELISA kits (e.g., ELISA with E protein as target) with a large sample size is required for elucidation of the kinetics of IgM and IgG responses to Zika virus infection in human serum.Fig. 3


Viral and serological kinetics in Zika virus-infected patients in South Korea
Profile of IgM and IgG responses to Zika virus infection in human serum. ELISA was performed using Anti-Zika Virus IgM/IgG ELISA kits (Euroimmun, Germany). a IgM ELISA response, b IgG ELISA response; the different symbols represent each patient. Interpretation of the results was based on the ratio of optical density of the patient serum over the value of the calibrator, according to the manufacturer’s instructions. Ratio < 0.8 indicates a negative result, 0.8 ≤ ratio < 1.1 indicates a borderline result, and ratio ≥ 1.1 indicates a positive result
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5383943&req=5

Fig3: Profile of IgM and IgG responses to Zika virus infection in human serum. ELISA was performed using Anti-Zika Virus IgM/IgG ELISA kits (Euroimmun, Germany). a IgM ELISA response, b IgG ELISA response; the different symbols represent each patient. Interpretation of the results was based on the ratio of optical density of the patient serum over the value of the calibrator, according to the manufacturer’s instructions. Ratio < 0.8 indicates a negative result, 0.8 ≤ ratio < 1.1 indicates a borderline result, and ratio ≥ 1.1 indicates a positive result
Mentions: The duration for which antibodies against Zika virus remain detectable in patient’s serum has not yet been established. The humoral immune response to Zika virus after infection was investigated using commercial kits (ELISA and gold rapid test). Anti-Zika Virus IgM and IgG ELISA kits from Euroimmun Inc. (Germany) were successfully used for detection of anti-Zika virus antibodies in 8 of the 9 (88.9%) patients (Fig. 3). However, no positive results were obtained using the Quantitative Human Zika Virus IgM ELISA kit (MyBioSource Inc., Lot E160512AI) and Zika virus IgM/IgG Ab Rapid Test (Biocan Diagnostics Inc., Lot B1815C021616). It could be concluded that the latter two kits were unacceptable for Zika virus testing and require improvement in terms of sensitivity; this was the first evaluation report for the two kits. Using the Euroimmun ELISA kit, IgM against Zika virus was detected as early as 2 days after the symptom onset and IgG was detected from 8 days after the symptom onset (Fig. 3). Of the seven patients whose serum samples were reactive to ELISA and for whom the days of symptom onset available, IgM was detected in acute-phase sera drawn from 4 (57.1%) patients, within 6 days post-onset. However, IgM was positive in all seven patients (100%) from 8 days post-onset. The IgM and IgG were maintained at detectable levels until 41 days and 52 days after the symptom onset, respectively. It is well known that IgM against flaviviruses, including dengue, West Nile, and Japanese encephalitis viruses, as indicated by ELISA, persist for up to several months and up to a year in the case IgG [12–14]. However, it was found that anti-Zika virus IgM antibody titer in patients 2, 3, and 6 fell to equivocal or negative levels at 42, 52, and 34 days post-onset (Fig. 3), respectively. The short duration of antibody detectability in those cases, as indicated by the Euroimmun ELISA, may be caused by the use of nonstructural protein 1 (NS 1) rather than E protein as a diagnostic marker. Further testing using other types of ELISA kits (e.g., ELISA with E protein as target) with a large sample size is required for elucidation of the kinetics of IgM and IgG responses to Zika virus infection in human serum.Fig. 3

View Article: PubMed Central - PubMed

ABSTRACT

Zika virus is a mosquito-borne flavivirus that causes clinical symptoms similar to those observed in dengue and chikungunya virus infections. The Korea Centers for Disease Control and Prevention initiated laboratory testing using a real-time reverse transcription-polymerase chain reaction in January 2016. More than 1,000 suspected cases of infection were tested and nine were confirmed as imported cases of Zika virus infection from January to July 2016. The travel destinations of the infected individuals were Brazil, Philippines, Viet Nam, Guatemala, Puerto Rico, and the Dominican Republic. Phylogenetic analysis based on the partial envelope gene indicated that the viruses belonged to the Asian genotype circulating in South America. We further investigated the duration for which the viral RNA and virus-specific antibodies were detectable after the symptom onset. After the day of symptom onset, Zika virus was detectable until 6 days in serum, 14 days in urine and saliva, and 58 days in semen. Immunoglobulin M against Zika virus was detected as early as 2 days after the symptom onset and was maintained at these levels until 41 days, whereas Immunoglobulin G was detectable from 8 days after the symptom onset and was maintained until 52 days. These findings would help diagnostic laboratories improve their testing programs for Zika virus infection.

No MeSH data available.


Related in: MedlinePlus