Research Article For reprint orders, please contact: reprints@futuremedicine.com Usefulness of human herpes simplex virus type 1 genotyping for tracing the geographical origins of unidentifed cadavers Hisako Saitoh* ,1 , Hiroshi Ikegaya 2 , Koichi Sakurada 3 , Hiroyuki Inoue 1 , Sayaka Nagasawa 1 , Ayaka Sakuma 1 , Namiko Ishii 1,3 , Go Inokuchi 1 , Fumiko Chiba 1,4 , Suguru Torimitsu 1,4 & Hirotaro Iwase 1,4 1 Department of Legal Medicine, Graduate School of Medicine, Chiba University, 1–8–1 Inohana, Chuo-ku, Chiba-shi, Chiba 260–8670, Japan 2 Department of Legal Medicine, Kyoto Prefectural University of Medicine, Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602–8566, Japan 3 Department of Forensic Dentistry, Graduate School of Medical & Dental Sciences, Tokyo Medical & Dental University, 1–5–45 Yushima, Bunkyo-ku, Tokyo 113–8510, Japan 4 Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7–3–1 Hongo, Bunkyo-ku, Tokyo, 113–0033, Japan * Author for correspondence: hms1466@faculty.chiba-u.jp Aim: We examined the possibility of tracing the origins of cadavers based on the geographic distribution of genotypes of the latent human herpes simplex virus type 1 (HSV-1). Materials & methods: PCR of the V1 region (667 bp) was performed using DNA from human trigeminal ganglia of 107 Japanese cadavers. The phylogenetic analysis was performed using 16 cadavers in Chiba district and 84 reference sequences in the world. Results: The HSV-1 DNA detection rate was 54.2% and it increased with age. This phylogenetic tree showed four large clusters, types I–IV (African, European, Asian and the mixed-type), and two subclusters (Japanese–Korean type and Japanese–Chinese type) in type III. Conclusion: HSV-1 genotype is possible to trace the geographical origin of unidentifed cadavers. First draft submitted: 28 February 2018; Accepted for publication: 5 April 2018; Published online: 23 April 2018 Keywords: forensic science • HSV-1 • phylogenetic tree When a large number of deaths occur in large-scale disasters such as fire, flood and terrorist attacks, or when unidentified bodies are recovered, the first task is to determine their identity. According to the Center for Research on the Epidemiology of Disasters, a cooperative agency of the United Nations, the number of deaths due to natural disasters in 2011 was 30,773 of which, 64.5% of the deaths were attributed to the Great East Japan Earthquake. Difficulty in confirming identity depends on factors such as the state of the cadaver, environmental conditions and elapsed time since death. To aid in determining identity, all possible information should be collected. Due to the close relationship between the viral DNA polymorphism that causes acquired latent infection in humans, we tried to use the genome type of the virus to trace the geographical origin of unidentified cadavers [1]. Although reports on the JC virus [2], BK virus [3], EB virus [4] and the hepatitis B virus [5] show a high infection rate in adulthood, their detection rate in cadavers is lower. The detection rates of JC virus, BK virus, EB virus and hepatitis B virus were 45% [2], 30.5% [3], 18% [4] and 3.9% [5], respectively. Therefore, we focused on the herpes simplex virus type 1 (HSV-1). An estimated 3.7 billion people under the age of 50, or 67% of the world’s population were infected with HSV-1 in 2012. The estimated morbidity rate is the highest in Africa (87%) and the lowest in the Americas (40–50%). The prevalence of HSV-1 generally reaches over 40% by 15 years of age, before increasing to 60–90% in older adults [6]. The primary acquisition of HSV-1 is becoming progressively delayed in many developed countries, in contrast to the developing countries where the viruses are acquired early in life and are prevalent [7]. As the prevalence rate of Future Virol. (Epub ahead of print) ISSN 1746-0794 10.2217/fvl-2018-0039 C  2018 Future Medicine Ltd