Open Access Research article

Increased alpha-9 human papillomavirus species viral load in human immunodeficiency virus positive women

Zizipho ZA Mbulawa16, Leigh F Johnson2, Dianne J Marais1, Inger Gustavsson4, Jennifer R Moodley3, David Coetzee2, Ulf Gyllensten4 and Anna-Lise Williamson15*

Author Affiliations

1 Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Anzio Road, Observatory, 7925 Cape Town, South Africa

2 Centre for Infectious Disease Epidemiology and Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa

3 School of Public Health and Family Medicine, Women’s Health Research Unit, University of Cape Town, Cape Town, South Africa

4 Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, University of Uppsala, S-751 85 Uppsala, Sweden

5 National Health Laboratory Service, Groote Schuur Hospital, Observatory, Cape Town 7925, South Africa

6 Center for HIV and STIs, National Institute for Communicable Disease, National Health Laboratory Service, Groote Schuur Hospital, Observatory, Cape Town 7925, South Africa

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BMC Infectious Diseases 2014, 14:51  doi:10.1186/1471-2334-14-51

Published: 31 January 2014

Abstract

Background

Persistent high-risk (HR) human papillomavirus (HPV) infection and increased HR-HPV viral load are associated with the development of cancer. This study investigated the effect of human immunodeficiency virus (HIV) co-infection, HIV viral load and CD4 count on the HR-HPV viral load; and also investigated the predictors of cervical abnormalities.

Methods

Participants were 292 HIV-negative and 258 HIV-positive women. HR-HPV viral loads in cervical cells were determined by the real-time polymerase chain reaction.

Results

HIV-positive women had a significantly higher viral load for combined alpha-9 HPV species compared to HIV-negative women (median 3.9 copies per cell compared to 0.63 copies per cell, P = 0.022). This was not observed for individual HPV types. HIV-positive women with CD4 counts >350/μl had significantly lower viral loads for alpha-7 HPV species (median 0.12 copies per cell) than HIV-positive women with CD4 ≤350/μl (median 1.52 copies per cell, P = 0.008), but low CD4 count was not significantly associated with increased viral load for other HPV species. High viral loads for alpha-6, alpha-7 and alpha-9 HPV species were significant predictors of abnormal cytology in women.

Conclusion

HIV co-infection significantly increased the combined alpha-9 HPV viral load in women but not viral loads for individual HPV types. High HR-HPV viral load was associated with cervical abnormal cytology.

Keywords:
Human papillomavirus; Human immunodeficiency virus; Viral load