Giuseppe
Emeritus
The Natural Viral Load Profile of Patients With Pandemic 2009 Influenza A(H1N1) and the Effect of Oseltamivir Treatment (CHEST, abstract, edited)
[Source: Chest, full text: <cite cite="http://chestjournal.chestpubs.org/content/137/4/759.short?rss=1">The Natural Viral Load Profile of Patients With Pandemic 2009 Influenza A(H1N1) and the Effect of Oseltamivir Treatment ? CHEST</cite>. Abstract, edited.]
The Natural Viral Load Profile of Patients With Pandemic 2009 Influenza A(H1N1) and the Effect of Oseltamivir Treatment
1. Iris W. Li, MD, 2. Ivan F. Hung, MD, 3. Kelvin K. To, MD, 4. Kwok-Hung Chan, PhD, 5. Samson S. Y. Wong, MD, 6. Jasper F. Chan, MD, 7. Vincent C. Cheng, MD, 8. Owen T. Tsang, MD, 9. Sik-To Lai, MD, 10. Yu-Lung Lau, MD and 11. Kwok-Yung Yuen, MD
Author Affiliations
1. From the Department of Microbiology (Drs Li, To, K.-H. Chan, Wong, J. F. Chan, Cheng, and Yuen), the Department of Medicine (Dr Hung), and the Department of Paediatrics and Adolescent Medicine (Dr Lau), Queen Mary Hospital, The University of Hong Kong; and the Department of Medicine and Geriatrics (Drs Tsang and Lai), Princess Margaret Hospital, Hong Kong Special Administrative Region, China.
1. Correspondence to: Kwok-Yung Yuen, MD, Carol Yu Centre for Infection and Division of Infectious Diseases, Department of Microbiology, The University of Hong Kong, 4/F University Pathology Bldg, 102 Pokfulam Rd, Queen Mary Hospital, Hong Kong; e-mail: kyyuen@hkucc.hku.hk
Abstract
Background:
The natural history of viral shedding from the upper respiratory tract of the new pandemic 2009 influenza A(H1N1) and the effect of oseltamivir treatment were uncertain.
Methods:
A retrospective cohort study involving 145 consecutive patients with specimens positive by reverse transcriptase-polymerase chain reaction for the matrix and new H1 genes was conducted.
Results:
The nontreated and oseltamivir-treated patients were comparable in their viral load at presentation, demography, and the presenting symptoms. No correlation was observed between viral load with age and number of symptoms. Viral load of nasopharyngeal aspirate (NPA) was significantly lower in treated than in nontreated patients at day 5 after symptom onset. When oseltamivir was initiated ≤ 2 days after symptom onset, a greater rate of viral load reduction in NPA of treated patients than that of nontreated patients was observed (−0.638 [95% CI, −0.809 to −0.466] vs −0.409 [95% CI, −0.663 to −0.185] log10 copies/mL/d post-symptom onset), and the viral load was undetectable at day 6 after oseltamivir initiation, which was 1 day earlier than that of those whose treatment was initiated > 2 days of symptom onset. The viral load was inversely correlated with concomitant absolute lymphocyte count in nontreated patients (Pearson correlation coefficient [r] = −0.687, P = .001) and treated patients (Pearson r = −0.365, P < .001). Resolution of fever was 1.4 days later in nontreated than treated patients (P = .012)
Conclusions:
The natural viral load profile was described. Oral oseltamivir suppresses viral load more effectively when given early in mild cases of pandemic 2009 influenza A(H1N1) infections.
Footnotes
* Funding/Support: This study was partially supported by the HKSAR Research Fund for the Control of Infectious Diseases.
* Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestpubs.org/site/misc/reprints.xhtml).
* Abbreviations: H274Y histidine 274-to-tyrosine mutation, Hb hemoglobin, lym absolute lymphocyte, NPA nasopharyngeal aspirate, NPS nasopharyngeal swab, NTS naso-throat swab, pandemic A(H1N1) pandemic 2009 influenza A(H1N1), plt platelet, RT-PCR reverse transcriptase-polymerase chain reaction
* Received December 22, 2009. Accepted December 23, 2009.
* ? 2010 American College of Chest Physicians
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[Source: Chest, full text: <cite cite="http://chestjournal.chestpubs.org/content/137/4/759.short?rss=1">The Natural Viral Load Profile of Patients With Pandemic 2009 Influenza A(H1N1) and the Effect of Oseltamivir Treatment ? CHEST</cite>. Abstract, edited.]
The Natural Viral Load Profile of Patients With Pandemic 2009 Influenza A(H1N1) and the Effect of Oseltamivir Treatment
1. Iris W. Li, MD, 2. Ivan F. Hung, MD, 3. Kelvin K. To, MD, 4. Kwok-Hung Chan, PhD, 5. Samson S. Y. Wong, MD, 6. Jasper F. Chan, MD, 7. Vincent C. Cheng, MD, 8. Owen T. Tsang, MD, 9. Sik-To Lai, MD, 10. Yu-Lung Lau, MD and 11. Kwok-Yung Yuen, MD
Author Affiliations
1. From the Department of Microbiology (Drs Li, To, K.-H. Chan, Wong, J. F. Chan, Cheng, and Yuen), the Department of Medicine (Dr Hung), and the Department of Paediatrics and Adolescent Medicine (Dr Lau), Queen Mary Hospital, The University of Hong Kong; and the Department of Medicine and Geriatrics (Drs Tsang and Lai), Princess Margaret Hospital, Hong Kong Special Administrative Region, China.
1. Correspondence to: Kwok-Yung Yuen, MD, Carol Yu Centre for Infection and Division of Infectious Diseases, Department of Microbiology, The University of Hong Kong, 4/F University Pathology Bldg, 102 Pokfulam Rd, Queen Mary Hospital, Hong Kong; e-mail: kyyuen@hkucc.hku.hk
Abstract
Background:
The natural history of viral shedding from the upper respiratory tract of the new pandemic 2009 influenza A(H1N1) and the effect of oseltamivir treatment were uncertain.
Methods:
A retrospective cohort study involving 145 consecutive patients with specimens positive by reverse transcriptase-polymerase chain reaction for the matrix and new H1 genes was conducted.
Results:
The nontreated and oseltamivir-treated patients were comparable in their viral load at presentation, demography, and the presenting symptoms. No correlation was observed between viral load with age and number of symptoms. Viral load of nasopharyngeal aspirate (NPA) was significantly lower in treated than in nontreated patients at day 5 after symptom onset. When oseltamivir was initiated ≤ 2 days after symptom onset, a greater rate of viral load reduction in NPA of treated patients than that of nontreated patients was observed (−0.638 [95% CI, −0.809 to −0.466] vs −0.409 [95% CI, −0.663 to −0.185] log10 copies/mL/d post-symptom onset), and the viral load was undetectable at day 6 after oseltamivir initiation, which was 1 day earlier than that of those whose treatment was initiated > 2 days of symptom onset. The viral load was inversely correlated with concomitant absolute lymphocyte count in nontreated patients (Pearson correlation coefficient [r] = −0.687, P = .001) and treated patients (Pearson r = −0.365, P < .001). Resolution of fever was 1.4 days later in nontreated than treated patients (P = .012)
Conclusions:
The natural viral load profile was described. Oral oseltamivir suppresses viral load more effectively when given early in mild cases of pandemic 2009 influenza A(H1N1) infections.
Footnotes
* Funding/Support: This study was partially supported by the HKSAR Research Fund for the Control of Infectious Diseases.
* Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestpubs.org/site/misc/reprints.xhtml).
* Abbreviations: H274Y histidine 274-to-tyrosine mutation, Hb hemoglobin, lym absolute lymphocyte, NPA nasopharyngeal aspirate, NPS nasopharyngeal swab, NTS naso-throat swab, pandemic A(H1N1) pandemic 2009 influenza A(H1N1), plt platelet, RT-PCR reverse transcriptase-polymerase chain reaction
* Received December 22, 2009. Accepted December 23, 2009.
* ? 2010 American College of Chest Physicians
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