Phylogenetic Demonstration of Two Cases of Perinatal Human Immunodeficiency Virus Type 2 Infection Diagnosed in Adulthood

Abstract

HIV-2 infection was diagnosed in two patients 15 and 24 years of age and, thereafter, in their mothers. Epidemiological data suggested that vertical transmission was the most probable mode of infection in both patients (Mota-Miranda A, et al.: AIDS 2001;15:2460-2461). Phylogenetic analysis of env C2-C3 sequences from the patients and their mothers was used in an attempt to confirm or exclude the events of perinatal HIV-2 transmission. Sequences from each putative transmission pair formed monophyletic clusters in phylogenetic analysis, a clear indication of common ancestry. Interpatient nucleotide distances increased with the period of infection being consistent with long-term infection. In conclusion, the results are consistent with an epidemiological linkage between the viruses infecting each mother-child pair and support the occurrence of perinatal HIV-2 infection in both cases. Application of similar phylogeny methods to other suspected transmission cases may permit a better understanding of the epidemiology and molecular evolution of HIV-2.

Synonymous Substitution Rates Predict HIV Disease Progression as a Result of Underlying Replication Dynamics

“…In contrast, HIV-2 patients had dS rates that were more comparable with HIV-1 group M slow progressors ( Table 2). The two published HIV-2 datasets (P7P8 and P9P10) represent cases of perinatal transmission only diagnosed in adulthood [37], as expected, given the slow nature of HIV-2 disease progression. HIV-2 dN rates are in the same range of HIV-1 dN rates in both moderate and slow progressors.…”

“…Since only three or four sequences were available per patient, these sequences were analyzed as one single dataset with the internal and backbone rate calculated as the mean rate for only within-host internal branches and backbone branches, respectively. Finally, we analyzed data from three HIV-2 mother-child transmission pairs [37], including unpublished sequences for one pair (P3P4). These sequences were obtained using methods described elsewhere [37] and are available from GenBank.…”

“…Finally, we analyzed data from three HIV-2 mother-child transmission pairs [37], including unpublished sequences for one pair (P3P4). These sequences were obtained using methods described elsewhere [37] and are available from GenBank. Since only one sample of cloned sequences was available for both mother and child at the same time, rates were estimated by specifying a normal prior distribution on the time to the most recent common ancestor based on the time of birth; monophyletic constraints were imposed on both the mother and child sequences.…”

“…Found at doi:10.1371/journal.pcbi.0030029.st003 (36 KB DOC). [33,36], and HIV-2 [37,63,65] datasets. The HIV-1 group M infected patients are ordered according to increasing progression time.…”

Synonymous Substitution Rates Predict HIV Disease Progression as a Result of Underlying Replication Dynamics

“…Substitution rates and standard deviations are listed in substitutions per site per month for HIV-1 group M (subtype B, 14), HIV-1 group O [33,36], and HIV-2 [37,63,65] datasets. The HIV-1 group M infected patients are ordered according to increasing progression time.…”