JC Virus Genotyping Can Be Used to Narrow down the Native Place of Persons from Urine Stains

Forensic application of Epstein-Barr virus genotype: Correlation between viral genotype and geographical area

Using 50 forensic blood samples, the latent membrane protein 2A (LMP-2A) gene of Epstein-Barr virus (EBV) DNA was amplified to find a geographic correlation among the EBV genotypes. EBV DNA was detected in nine samples. From a phylogenetic analysis using 18 reported sequences as a reference, six EBV subtypes (Ia, Ib, Ic IIa, IIb, and IIc) were found. Japanese isolates were included in subtypes Ia or IIa. All the Asian reference isolates, except isolate D6, were included in subtype Ia or IIa. Mediterranean, an Alaskan and other African isolates were included in types Ib, Ic, IIb and IIc. The EBV genotype in the LMP-2A gene was thus demonstrated as being correlated with the host's geographical location. Typing in the EBV-associated nuclear antigen 2 gene was not related to that in the LMP-2A gene. Detection of the EBV genotype in the LMP-2A gene may be useful for determining the geographical origins of unidentified cadavers.

Geographical identification of cadavers by human parasites

Increasing numbers of unidentified cadavers have recently become an important forensic problem in many countries. To identify such cadavers, DNA typing method is widely used. However, as this technique requires reference DNA samples, a method that would quickly narrow down possible candidates for the cadavers is needed to enable rapid identification. Unfortunately, no really reliable methods suitable for this purpose have been available; however, methods using the human parasites, JC virus, BK virus and EB virus, have been reported. These new methods narrow down the candidates by elucidating geographic origins. Though not detectable in all cases, results using such methods with several parasites have enabled us to estimate geographic origins of unidentified cadavers with a high detection rate.

BK virus genotype distribution offers information of tracing the geographical origins of unidentified cadaver

There are no efficient methods to determine the geographic origin of unidentified cadavers. We showed earlier that the geographical distribution of the JC virus genotype detected from human kidneys indicates the host's geographical origin. As there are still cadavers from which we cannot detect the JC virus (JCV), we investigated whether the genotype of another virus species belonging to the same family, human BK virus (BKV), could also be used to detect human geographical origin. BKV was found in 11 of 36 cases (30.5%). Even in the seven JCV-negative cases, the host's geographic origin could be estimated from the BKV genotype. Four subjects were positive for both the BKV and JCV. As the distribution areas of BKV and JCV genotypes are not identical, it is possible to narrow down the geographic area that any cadaver originates from.