0
Original Research: INFLUENZA A(H1N1) INFECTION |

The Natural Viral Load Profile of Patients With Pandemic 2009 Influenza A(H1N1) and the Effect of Oseltamivir Treatment

Iris W. Li, MD; Ivan F. Hung, MD; Kelvin K. To, MD; Kwok-Hung Chan, PhD; Samson S. Y. Wong, MD; Jasper F. Chan, MD; Vincent C. Cheng, MD; Owen T. Tsang, MD; Sik-To Lai, MD; Yu-Lung Lau, MD; Kwok-Yung Yuen, MD
Author and Funding Information

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.

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


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).


© 2010 American College of Chest Physicians


Chest. 2010;137(4):759-768. doi:10.1378/chest.09-3072
Text Size: A A A
Published online

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.

Figures in this Article

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Figures

Tables

References

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Sign In to Access Full Content

MEMBER & INDIVIDUAL SUBSCRIBER

Want Access?

NEW TO CHEST?

Become a CHEST member and receive a FREE subscription as a benefit of membership.

Individuals can purchase this article on ScienceDirect.

Individuals can purchase a subscription to the journal.

Individuals can purchase a subscription to the journal or buy individual articles.

Learn more about membership or Purchase a Full Subscription.

INSTITUTIONAL ACCESS

Institutional access is now available through ScienceDirect and can be purchased at myelsevier.com.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Find Similar Articles
CHEST Journal Articles
PubMed Articles
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543