The identification of genetic material from pathogenic organisms in ancient tissues provides a powerful tool for the study of certain infectious diseases in historic populations. We have obtained tissue samples from the genital areas of 12 mummies in the American Museum of Natural History collection in New York, N.Y. The mummies were excavated in the Andes Mountain region of South America, and radiocarbon dating estimates that the mummies date from A.D. 140 to 1200. DNAs were successfully extracted from all tissues and were suitable for PCR analysis. PCRs were carried out to detect Mycobacterium tuberculosis complex and mycobacteria other than M. tuberculosis (MOTB). M. tuberculosis complex was detected in 2 out of 12 samples, and MOTB were detected in 7 samples. This study confirmed the adequate preservation of genetic material in mummified tissues and the existence of mycobacteria, including M. tuberculosis, in historic populations in South America.

To overcome the instability of viral RNA, we carried out hepatitis C virus (HCV) RNA detection in dried serum spotted onto filter paper. The spotted serum samples were stored at room temperature and then processed for PCR assay at intervals of 1, 2, 3, and 4 weeks. The results showed that serum HCV RNA is stable in a dried condition, as it was detectable in spotted serum samples stored for 4 weeks at room temperature. Furthermore, although the HCV RNA titer showed an ∼10-fold reduction in virus yield in dried serum stored at room temperature for 4 weeks, the PCR results of frozen serum samples and dried serum samples matched completely. This storage method facilitates transport and analysis by nucleic acid amplification techniques even when freezing conditions are not available.

Using the PCR assay, we found a high prevalence of TT virus (TTV) DNA in saliva and semen from patients who were seropositive for TTV. This finding suggests that the presence of TTV in body fluids other than serum may affect the routes of viral transmission. Recently, the genome from a novel DNA virus, termed the TT virus (TTV), was isolated from the serum of patients with posttransfusion non-A-G hepatitis by using representational difference analysis (6, 8). TTV is an unenveloped singlestranded DNA virus, with an isopycnic density of 1.31 to 1.32 g/ml in CsCl (8). The TTV genome has two possible open reading frames, capable of encoding 770 and 202 amino acids. Due to the genome structure and its banding in buoyant density gradient centrifugation, TTV might be most closely related to Circoviridae among the known animal virus families (3, 4, 10). The TTV sequence was detected in sera and liver tissues from liver disease patients, suggesting that TTV might be responsible for a part of acute and chronic liver disease of unknown etiology (2, 8). On the other hand, it has been reported that TTV infection does not induce significant liver damage (5). Members of our group recently reported that TTV infection is widespread in the general population worldwide and suggested that TTV may be a common DNA virus in humans (1). This implies that the routes of TTV transmission may differ from the routes of hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis G virus (HGV) transmission. The presence of virus in body fluids other than serum, such as saliva and semen, may affect the routes of viral transmission. Accordingly, we analyzed whether TTV is present in extravascular compartments. Paired samples of serum, saliva, and semen were obtained from 10 drug addicts (all males, ranging in age from 18 to 54 years), either intravenous drug users or heroin smokers. Four of them were coinfected with HCV, but no evidence of HBV, HGV, or human immunodeficiency virus infections was obtained by PCR assays. Saliva and semen were collected in sterile tubes and stored at Ϫ30°C until use. Informed consent was obtained from the participants in this study. DNA was extracted from 100 l of serum, saliva, and semen, respectively, using a nucleic acid extraction kit (SepaGene RV-R; Sanko Junyaku Co., Ltd., Tokyo, Japan). The semen was diluted to twice its original volume with phosphate-buffered saline and used for DNA extraction. TTV DNA was amplified by PCR as described previously (1). In brief, the thermocycler was programmed first to preheat at 95°C for 10 min to activate Ampli-Taq Gold DNA polymerase (Perkin-Elmer, Norwalk, Conn.), followed by 55 cycles consisting of 94°C for 20 s, 60°C for 20 s, and 72°C for 30 s using a Perkin-Elmer 9600 or 9700 thermal cycler. The sequences of the TTV-specific primers were 5Ј-G