Thus, as the frequency of multiple infections increased from ∼80% cells being singly infected (M drawn from a distribution based on a viral dynamics model) to all cells triply infected (M = 3), Ne decreased from ∼105, in agreement with Rouzine and Coffin, to ∼102 (Fig. 9).
A meta-analysis that included 30,848 cases of ICC worldwide showed that the proportion of HPV multiple infections increased in the last years from 4%to15%5% [ 12], probably reflecting the use of commercial tests more prone to detect multiple infections in recent studies.
However, none of these differences were statistically significant, but of course, a multiple HPV infection increases the probability of harbouring a highly oncogenic HPV type.
Furthermore, we found an increase in multiple infections with increasing abnormal cytology and the MY-PCR system has been shown to detect twice as much samples with multiple HPV types as compared to the GP5+/6+ PCR system (Qu et al, 1997).
But, there is an association between multiple infections and increased risk of neoplasia compared to single infections [ 8, 13, 14].
It is possible that a combination of factors including a compromised immune system overloaded with multiple infections could increase the field of injury, leading to chronic inflammation and subsequent lesion progression.
It is impossible to even write down the equilibria of the system where multiple infection leads to an increased burst size of infected cells.
In our study, prevalence of any or multiple cervical HPV infection increased with the number of sexual partners reported by FSW, a finding that has been well documented by others [ 15, 16].
HPV16, HPV31, HPV33, HPV58, and multiple HPV genotype infection increased the risk of cytology abnormalities in Pearl River Delta Region and might be useful for the screening, preventing, treating, and monitoring of pre-cancer lesions in southern China.
Theoretical analyses predict that the within-host dynamics of microparasites in multiple infected hosts may have important consequences in the evolution of their virulence [11] [14], and there is evidence that multiple infection may result in either increased or reduced virulence [e.g., [15] [17]].
