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

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.


Duration of detectability of Zika viral RNA in different specimens. qRT-PCR was performed using a commercial kit (PrimerDesign Ltd., UK) with serum, urine, saliva, and semen samples. A sample with a threshold cycle (CT) number ≤ 40 was considered to be Zika-positive. In patient 3, the final collection of semen was performed at 86th day after the symptom onset and the result was negative. It was not presented for the sake of brevity
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Fig2: Duration of detectability of Zika viral RNA in different specimens. qRT-PCR was performed using a commercial kit (PrimerDesign Ltd., UK) with serum, urine, saliva, and semen samples. A sample with a threshold cycle (CT) number ≤ 40 was considered to be Zika-positive. In patient 3, the final collection of semen was performed at 86th day after the symptom onset and the result was negative. It was not presented for the sake of brevity

Mentions: Although individual variation was observed and sample numbers were limited, the period over which viral RNA was detectable differed according to the sample type (Fig. 2). Overall, after the day of symptom onset, viral RNA was detectable until 6 days in serum, 14 days in urine and saliva, and 58 days in semen, respectively. In detail, viral RNA was detected only in 5 out of 10 (50%) acute-phase serum specimens (within a week of onset) and the detection rate fell to zero (0/10) in sera collected between 1 and 2 weeks following the symptom onset. However, viral RNA was detectable in all of the 9 (100%) urine samples drawn within a week of onset, and the rate fell to 50% (5/10) in urine drawn between 1 and 2 weeks following the symptom onset. In case of saliva, viral RNA was detected in the 2 samples (100%) drawn within a week of onset, and the detection rate fell to 50% (5/10) in the sample drawn between 1 and 2 weeks following the symptom onset. The results indicate that urine and saliva samples are preferable over serum samples, as they are obtained easily through painless procedures and show higher virus detection rates than those observed in serum samples. Our results are similar with those of previous reports describing the duration of viral RNA detection in different specimens [7–9]. The recovery of Zika virus was reported from urine and saliva as well as from serum and semen [10, 11]. The viruses were isolated from 2 out of 9 patients by inoculating the RT-PCR positive specimens to mammalian cells (BHK-21, Vero, and LLC-MK2); these data will be reported in the near future.Fig. 2


Viral and serological kinetics in Zika virus-infected patients in South Korea
Duration of detectability of Zika viral RNA in different specimens. qRT-PCR was performed using a commercial kit (PrimerDesign Ltd., UK) with serum, urine, saliva, and semen samples. A sample with a threshold cycle (CT) number ≤ 40 was considered to be Zika-positive. In patient 3, the final collection of semen was performed at 86th day after the symptom onset and the result was negative. It was not presented for the sake of brevity
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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

Fig2: Duration of detectability of Zika viral RNA in different specimens. qRT-PCR was performed using a commercial kit (PrimerDesign Ltd., UK) with serum, urine, saliva, and semen samples. A sample with a threshold cycle (CT) number ≤ 40 was considered to be Zika-positive. In patient 3, the final collection of semen was performed at 86th day after the symptom onset and the result was negative. It was not presented for the sake of brevity
Mentions: Although individual variation was observed and sample numbers were limited, the period over which viral RNA was detectable differed according to the sample type (Fig. 2). Overall, after the day of symptom onset, viral RNA was detectable until 6 days in serum, 14 days in urine and saliva, and 58 days in semen, respectively. In detail, viral RNA was detected only in 5 out of 10 (50%) acute-phase serum specimens (within a week of onset) and the detection rate fell to zero (0/10) in sera collected between 1 and 2 weeks following the symptom onset. However, viral RNA was detectable in all of the 9 (100%) urine samples drawn within a week of onset, and the rate fell to 50% (5/10) in urine drawn between 1 and 2 weeks following the symptom onset. In case of saliva, viral RNA was detected in the 2 samples (100%) drawn within a week of onset, and the detection rate fell to 50% (5/10) in the sample drawn between 1 and 2 weeks following the symptom onset. The results indicate that urine and saliva samples are preferable over serum samples, as they are obtained easily through painless procedures and show higher virus detection rates than those observed in serum samples. Our results are similar with those of previous reports describing the duration of viral RNA detection in different specimens [7–9]. The recovery of Zika virus was reported from urine and saliva as well as from serum and semen [10, 11]. The viruses were isolated from 2 out of 9 patients by inoculating the RT-PCR positive specimens to mammalian cells (BHK-21, Vero, and LLC-MK2); these data will be reported in the near future.Fig. 2

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.