Viral Load of Human Papillomavirus (HPV) During Pregnancy and Its Association With HPV Vertical Transmission

Eméra Alice Bénard1,2, Ana Maria Carceller2,3,4, Marie-Hélène Mayrand5,6

  • 1Department of Social and Preventive Medicine, Université de Montréal, Montreal, Canada.

PubMed

Little is known on the dynamics of human papillomavirus (HPV) viral load during pregnancy and on the impact of viral load on HPV vertical transmission. We described viral loads for several genotypes during pregnancy and analyse its association with vertical transmission. Data were analysed from the HERITAGE study, a cohort of pregnant women recruited between 2010 and 2016 in three centres in Canada. Vaginal samples were collected at the first and third trimesters of pregnancy, placental samples were collected at birth, and conjunctival, oral, pharyngeal, and genital samples were collected in children at birth and 3 months were tested for HPV DNA and viral load by Linear Array essay. The association between viral load and vertical transmission was measured using logistic regression. Odd ratios (ORs) and their 95% Confidence intervals (CI) were adjusted for age of the mother. We included women in the cohort infected with the 13 most common genotypes during pregnancy (n = 287). A decrease in HPV viral load was observed during pregnancy (median difference between the third and first trimester of pregnancy = -0.005 copies/cell [p < 0.05]). Women with more than 2 HPV copies/cell (compared to those with ≤ 2 copies) at first trimester had a statistically significant higher risk of vertical transmission (adjusted OR = 6.41; 95% CI: 1.10-37.34 for any genotypes and OR = 17.17; 95% CI: 1.18-250.28 for HPV-16). Viral load values analysed continuously or categorized with different cut-offs showed comparable results. HPV viral load varied during pregnancy and was strongly associated with HPV vertical transmission. The results provide a better understanding of risk factors associated with vertical transmission.

Related Concept Videos

Viral Mutations00:36

Viral Mutations

A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material...
32.1K
Sexually Transmitted Infections01:26

Sexually Transmitted Infections

Sexually transmitted infections (STIs) are diseases transmitted primarily through unsafe sexual interactions. Bacteria, viruses, or parasites cause them and can result in severe health complications if untreated.ChlamydiaThe bacterium Chlamydia trachomatis is responsible for the disease Chlamydia, the most common STI in the United States. This peculiar pathogen requires human cells to reproduce, residing intracellularly. The initial infection often goes unnoticed because it typically does not...
261
Retroviruses02:33

Retroviruses

Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
12.2K
Retrovirus Life Cycles01:10

Retrovirus Life Cycles

Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...
45.6K
Mechanisms of Retrovirus-induced Cancers01:51

Mechanisms of Retrovirus-induced Cancers

Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
5.0K
Rous Sarcoma Virus (RSV) and Cancer01:03

Rous Sarcoma Virus (RSV) and Cancer

Rous Sarcoma virus or RSV was discovered by F. Peyton Rous in the year 1911 as a filterable transmissible agent that could cause tumors in chickens. He won a Nobel Prize for this discovery in 1966. His experiments clearly demonstrated that some cancers could be caused by infectious agents and led to the discovery of many more cancer-causing viruses in animals as well as humans.
RSV is a retrovirus that contains two copies of a plus-strand  RNA genome. Its genome consists of four main open...
4.9K