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Chronic hepatitis C virus (HCV) infection causes liver damage and can lead to cirrhosis and hepatocellular carcinoma. Transmission of HCV is via parenteral routes (blood transfusions, shared ‘dirty' needles, sexual intercourse, and vertical).In New Zealand (NZ), the epidemiology of HCV infection has not been well studied. It is estimated that approximately 50000 people are infected and the majority are unaware of the infection.1Worldwide, injecting drug use is the main source of transmission of HCV. A 2006/7 survey of drug use in NZ found that overall 1.4% of 16–65 year olds surveyed admitted to injecting drug use and rates were highest among respondents aged 45–54 years.2 Needle exchange programmes and reduced prevalence of injecting drug use in NZ should have led to a reduction in new cases of HCV infection via this route. Vertical transmission is now thought to be an important source of new HCV infections.Screening for HCV antibodies is not part of NZ's antenatal screening; most countries recommend targeted screening of pregnant women but acknowledge varying sensitivity of this approach.3The aim of this study was to anonymously test 1000 antenatal bloods at Labtests, Auckland's community laboratory, to determine the rate of HCV antibody reactivity among pregnant women in Auckland.Anti-HCV antibody testing was performed using the ADVIA Centaur HCV assay (Siemens Healthcare Diagnostics Inc. Tarrytown New York). Samples with an index value of ≥1.0 are considered reactive. Samples were identified by rubella serology requests (almost always performed as part of antenatal screening) on females. Samples a pregnancy panel (a computer code added for antenatal patients) were processed for anti-HCV antibodies.NHIs were obtained from the laboratory request number and sent without any laboratory data to the Ministry of Health (MoH) for ethnicity. The MoH analyst then removed the NHIs before sending the data back; laboratory data and age was combined with the ethnicity data using the laboratory number which was then removed. The only data saved contained age, ethnicity, and HCV antibody result. Data were not saved on the instrument or the laboratory information system.A grant from the NZ Hepatitis Foundation funded this study. Ethics approval was discussed with the NZ Ethics Committee and was determined not to be required as the study methods maintained anonymity and so the study was low risk.In total 1173 samples were tested for anti-HCV antibodies; of these 915 were from women known to be pregnant. Of these 915 women, the median age was 30 years (range 14–46). A range of ethnicities were seen including NZ European (275, 30%), Asian (138, 15%), Pacific (137, 15%), NZ Māori (95, 10%), Indian (94, 10%), other European (80, 9%), Cook Island Maori (27, 3%), and other (22, 2%). Ethnicity data were unavailable for 47 (5%) due to either no NHI or MOH not having the data.In total there were three anti-HCV antibody reactive samples (0.3%) of samples tested from pregnant women. The three positive tests were from women aged 23, 28, and 42 years, and of NZ European, Indian, and Asian ethnicity. Two samples were strongly reactive while one was low level reactive (just above the cut-off).A past review of HCV antibody reactivity and HCV RNA positivity in our laboratory demonstrated that low level reactive results are commonly associated with either past cleared infection or false reactivity of the assay.These data are reassuring. The prevalence of anti-HCV antibody reactivity among our cohort of pregnant women in the Auckland community was low at 0.3%. It is likely that at least one of these women does not have active HCV infection (with low-level reactivity). In addition, it is possible that the other two women may have spontaneously cleared their infection.Overall approximately 25% of acute infections clear spontaneously; however, women are more likely to clear than men, as are younger people (<40 years).4 Thus, it is possible that less than 0.3% of our cohort have active infection that would pose a potential risk of vertical transmission to their baby. Unfortunately we were not able to test for HCV RNA positivity in our samples.In summary, we have shown that HCV antibody reactivity is very uncommon among pregnant women in the Auckland community. NZ's current antenatal screening policy of not routinely testing for HCV is appropriate.Arlo Upton Clinical Microbiologist arlo.upton@labtests.co.nzMichael Herring Senior ScientistLabtests Mt Wellington Auckland, New Zealand

Summary

Abstract

Aim

Method

Results

Conclusion

Author Information

Acknowledgements

Correspondence

Correspondence Email

Competing Interests

Nesdale A, Baker M, Gane E, et al. Hepatitis C Infection in New Zealand: Estimating the current and future prevalence and impact. [Internet]. NZ Ministry of Health; 2000 [cited 2013 Jun 10]. Available from:http://www.moh.govt.nz/notebook/nbbooks.nsf/0/66D62562CFC858DCCC2576010082FDA6/$file/hepatitis%20c%20infection%20in%20nz%20.pdfMason K, Hewitt A, Stefanogiannis N. Drug Use in New Zealand: Key Results of the 2007/08 New Zealand Alcohol and Drug Use Survey. [Internet]. NZ Ministry of Health; 2010 [cited 2013 Jun 10]. Available from: http://www.health.govt.nz/system/files/documents/publications/drug-use-in-nz-v2-jan2010.pdfPrasad MR, Honegger JR. Hepatitis C Virus in Pregnancy. Am J Perinatol [Internet]. 2013 Feb [cited 2014 Jan 21];30(2). Available from:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3862252/Grebely J, Prins M, Hellard M, et al. Hepatitis C virus clearance, reinfection, and persistence, with insights from studies of injecting drug users: towards a vaccine. Lancet Infect Dis. 2012 May;12(5):408-14.

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Chronic hepatitis C virus (HCV) infection causes liver damage and can lead to cirrhosis and hepatocellular carcinoma. Transmission of HCV is via parenteral routes (blood transfusions, shared ‘dirty' needles, sexual intercourse, and vertical).In New Zealand (NZ), the epidemiology of HCV infection has not been well studied. It is estimated that approximately 50000 people are infected and the majority are unaware of the infection.1Worldwide, injecting drug use is the main source of transmission of HCV. A 2006/7 survey of drug use in NZ found that overall 1.4% of 16–65 year olds surveyed admitted to injecting drug use and rates were highest among respondents aged 45–54 years.2 Needle exchange programmes and reduced prevalence of injecting drug use in NZ should have led to a reduction in new cases of HCV infection via this route. Vertical transmission is now thought to be an important source of new HCV infections.Screening for HCV antibodies is not part of NZ's antenatal screening; most countries recommend targeted screening of pregnant women but acknowledge varying sensitivity of this approach.3The aim of this study was to anonymously test 1000 antenatal bloods at Labtests, Auckland's community laboratory, to determine the rate of HCV antibody reactivity among pregnant women in Auckland.Anti-HCV antibody testing was performed using the ADVIA Centaur HCV assay (Siemens Healthcare Diagnostics Inc. Tarrytown New York). Samples with an index value of ≥1.0 are considered reactive. Samples were identified by rubella serology requests (almost always performed as part of antenatal screening) on females. Samples a pregnancy panel (a computer code added for antenatal patients) were processed for anti-HCV antibodies.NHIs were obtained from the laboratory request number and sent without any laboratory data to the Ministry of Health (MoH) for ethnicity. The MoH analyst then removed the NHIs before sending the data back; laboratory data and age was combined with the ethnicity data using the laboratory number which was then removed. The only data saved contained age, ethnicity, and HCV antibody result. Data were not saved on the instrument or the laboratory information system.A grant from the NZ Hepatitis Foundation funded this study. Ethics approval was discussed with the NZ Ethics Committee and was determined not to be required as the study methods maintained anonymity and so the study was low risk.In total 1173 samples were tested for anti-HCV antibodies; of these 915 were from women known to be pregnant. Of these 915 women, the median age was 30 years (range 14–46). A range of ethnicities were seen including NZ European (275, 30%), Asian (138, 15%), Pacific (137, 15%), NZ Māori (95, 10%), Indian (94, 10%), other European (80, 9%), Cook Island Maori (27, 3%), and other (22, 2%). Ethnicity data were unavailable for 47 (5%) due to either no NHI or MOH not having the data.In total there were three anti-HCV antibody reactive samples (0.3%) of samples tested from pregnant women. The three positive tests were from women aged 23, 28, and 42 years, and of NZ European, Indian, and Asian ethnicity. Two samples were strongly reactive while one was low level reactive (just above the cut-off).A past review of HCV antibody reactivity and HCV RNA positivity in our laboratory demonstrated that low level reactive results are commonly associated with either past cleared infection or false reactivity of the assay.These data are reassuring. The prevalence of anti-HCV antibody reactivity among our cohort of pregnant women in the Auckland community was low at 0.3%. It is likely that at least one of these women does not have active HCV infection (with low-level reactivity). In addition, it is possible that the other two women may have spontaneously cleared their infection.Overall approximately 25% of acute infections clear spontaneously; however, women are more likely to clear than men, as are younger people (<40 years).4 Thus, it is possible that less than 0.3% of our cohort have active infection that would pose a potential risk of vertical transmission to their baby. Unfortunately we were not able to test for HCV RNA positivity in our samples.In summary, we have shown that HCV antibody reactivity is very uncommon among pregnant women in the Auckland community. NZ's current antenatal screening policy of not routinely testing for HCV is appropriate.Arlo Upton Clinical Microbiologist arlo.upton@labtests.co.nzMichael Herring Senior ScientistLabtests Mt Wellington Auckland, New Zealand

Summary

Abstract

Aim

Method

Results

Conclusion

Author Information

Acknowledgements

Correspondence

Correspondence Email

Competing Interests

Nesdale A, Baker M, Gane E, et al. Hepatitis C Infection in New Zealand: Estimating the current and future prevalence and impact. [Internet]. NZ Ministry of Health; 2000 [cited 2013 Jun 10]. Available from:http://www.moh.govt.nz/notebook/nbbooks.nsf/0/66D62562CFC858DCCC2576010082FDA6/$file/hepatitis%20c%20infection%20in%20nz%20.pdfMason K, Hewitt A, Stefanogiannis N. Drug Use in New Zealand: Key Results of the 2007/08 New Zealand Alcohol and Drug Use Survey. [Internet]. NZ Ministry of Health; 2010 [cited 2013 Jun 10]. Available from: http://www.health.govt.nz/system/files/documents/publications/drug-use-in-nz-v2-jan2010.pdfPrasad MR, Honegger JR. Hepatitis C Virus in Pregnancy. Am J Perinatol [Internet]. 2013 Feb [cited 2014 Jan 21];30(2). Available from:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3862252/Grebely J, Prins M, Hellard M, et al. Hepatitis C virus clearance, reinfection, and persistence, with insights from studies of injecting drug users: towards a vaccine. Lancet Infect Dis. 2012 May;12(5):408-14.

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contact nzmj@nzma.org.nz

View Article PDF

Chronic hepatitis C virus (HCV) infection causes liver damage and can lead to cirrhosis and hepatocellular carcinoma. Transmission of HCV is via parenteral routes (blood transfusions, shared ‘dirty' needles, sexual intercourse, and vertical).In New Zealand (NZ), the epidemiology of HCV infection has not been well studied. It is estimated that approximately 50000 people are infected and the majority are unaware of the infection.1Worldwide, injecting drug use is the main source of transmission of HCV. A 2006/7 survey of drug use in NZ found that overall 1.4% of 16–65 year olds surveyed admitted to injecting drug use and rates were highest among respondents aged 45–54 years.2 Needle exchange programmes and reduced prevalence of injecting drug use in NZ should have led to a reduction in new cases of HCV infection via this route. Vertical transmission is now thought to be an important source of new HCV infections.Screening for HCV antibodies is not part of NZ's antenatal screening; most countries recommend targeted screening of pregnant women but acknowledge varying sensitivity of this approach.3The aim of this study was to anonymously test 1000 antenatal bloods at Labtests, Auckland's community laboratory, to determine the rate of HCV antibody reactivity among pregnant women in Auckland.Anti-HCV antibody testing was performed using the ADVIA Centaur HCV assay (Siemens Healthcare Diagnostics Inc. Tarrytown New York). Samples with an index value of ≥1.0 are considered reactive. Samples were identified by rubella serology requests (almost always performed as part of antenatal screening) on females. Samples a pregnancy panel (a computer code added for antenatal patients) were processed for anti-HCV antibodies.NHIs were obtained from the laboratory request number and sent without any laboratory data to the Ministry of Health (MoH) for ethnicity. The MoH analyst then removed the NHIs before sending the data back; laboratory data and age was combined with the ethnicity data using the laboratory number which was then removed. The only data saved contained age, ethnicity, and HCV antibody result. Data were not saved on the instrument or the laboratory information system.A grant from the NZ Hepatitis Foundation funded this study. Ethics approval was discussed with the NZ Ethics Committee and was determined not to be required as the study methods maintained anonymity and so the study was low risk.In total 1173 samples were tested for anti-HCV antibodies; of these 915 were from women known to be pregnant. Of these 915 women, the median age was 30 years (range 14–46). A range of ethnicities were seen including NZ European (275, 30%), Asian (138, 15%), Pacific (137, 15%), NZ Māori (95, 10%), Indian (94, 10%), other European (80, 9%), Cook Island Maori (27, 3%), and other (22, 2%). Ethnicity data were unavailable for 47 (5%) due to either no NHI or MOH not having the data.In total there were three anti-HCV antibody reactive samples (0.3%) of samples tested from pregnant women. The three positive tests were from women aged 23, 28, and 42 years, and of NZ European, Indian, and Asian ethnicity. Two samples were strongly reactive while one was low level reactive (just above the cut-off).A past review of HCV antibody reactivity and HCV RNA positivity in our laboratory demonstrated that low level reactive results are commonly associated with either past cleared infection or false reactivity of the assay.These data are reassuring. The prevalence of anti-HCV antibody reactivity among our cohort of pregnant women in the Auckland community was low at 0.3%. It is likely that at least one of these women does not have active HCV infection (with low-level reactivity). In addition, it is possible that the other two women may have spontaneously cleared their infection.Overall approximately 25% of acute infections clear spontaneously; however, women are more likely to clear than men, as are younger people (<40 years).4 Thus, it is possible that less than 0.3% of our cohort have active infection that would pose a potential risk of vertical transmission to their baby. Unfortunately we were not able to test for HCV RNA positivity in our samples.In summary, we have shown that HCV antibody reactivity is very uncommon among pregnant women in the Auckland community. NZ's current antenatal screening policy of not routinely testing for HCV is appropriate.Arlo Upton Clinical Microbiologist arlo.upton@labtests.co.nzMichael Herring Senior ScientistLabtests Mt Wellington Auckland, New Zealand

Summary

Abstract

Aim

Method

Results

Conclusion

Author Information

Acknowledgements

Correspondence

Correspondence Email

Competing Interests

Nesdale A, Baker M, Gane E, et al. Hepatitis C Infection in New Zealand: Estimating the current and future prevalence and impact. [Internet]. NZ Ministry of Health; 2000 [cited 2013 Jun 10]. Available from:http://www.moh.govt.nz/notebook/nbbooks.nsf/0/66D62562CFC858DCCC2576010082FDA6/$file/hepatitis%20c%20infection%20in%20nz%20.pdfMason K, Hewitt A, Stefanogiannis N. Drug Use in New Zealand: Key Results of the 2007/08 New Zealand Alcohol and Drug Use Survey. [Internet]. NZ Ministry of Health; 2010 [cited 2013 Jun 10]. Available from: http://www.health.govt.nz/system/files/documents/publications/drug-use-in-nz-v2-jan2010.pdfPrasad MR, Honegger JR. Hepatitis C Virus in Pregnancy. Am J Perinatol [Internet]. 2013 Feb [cited 2014 Jan 21];30(2). Available from:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3862252/Grebely J, Prins M, Hellard M, et al. Hepatitis C virus clearance, reinfection, and persistence, with insights from studies of injecting drug users: towards a vaccine. Lancet Infect Dis. 2012 May;12(5):408-14.

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