Chinese Liver Flukes in Latrine Sediments From Wong Nimâ•Žs Property, San Bernardino, California: Archaeoparasitology of the Caltrans District Headquarters (Galley Proofs)

Parasitological analysis of 5 sediment samples from latrine deposits spanning the time period from about 1880 to the 1930s are presented. Two sediment samples are from a latrine used by EuropeanAmericans. Three sediment samples are from latrines used by ChineseAmericans on the property of Wong Nim, an important member of the Chinese community. Two of the Chinese latrines were positive for human parasites. The human parasites encountered include the human whipworm (Trichuris trichiura), the giant intestinal roundworm (Ascaris lubricoides, c.f.), and the Chinese liver fluke (Clonorchis sinensis). Evidence of the liver fluke is especially important. This parasite cannot complete its life cycle outside of its endemic range in Asia because suitable intermediate hosts are not present in the American continents. Its presence signals that at least some of the Chinese-Americans who used the latrines were immigrants who were infected in Asia and then sustained infections while in the Americas. Parasitological analysis of archaeological sediments can provide insights into human transhumance (Ferreira et al., 1984; Araújo et al., 1988; Reinhard et al., 1987; Reinhard, 1992; Matsui et al., 2003). The latter authors presented evidence of diplomatic legations in Japan that were parasitized with nonendemic species. Hevly et al. (1979) and Reinhard et al. (1987) reported finding Trichuris trichiura in a nonendemic region near modern Flagstaff, Arizona. Ferreira et al. (1984) discovered Diphyllobothrium pacificum eggs in coprolites recovered from a Chilean inland site, and this indicates that the prehistoric people who deposited the coprolites used both the coast and inland areas. Araújo et al. (1988) and Ferreira and Araújo (1996) used hookworm evidence to trace prehistoric long-distance migrations. Here, we present evidence of transcontinental introduction of the Chinese liver fluke to California with historic migrations. This study confirms an earlier, unpublished report of Chinese liver flukes from a historic Chinese community in Sacramento, California (Hall, 1982). Chinese populations moved into San Bernardino in 1867 (Costello and Hallaran, 2004; Costello et al., 2006). By 1880, the countywide Chinese population was about 150. Initially, they lived in various places throughout the town of San Bernardino. They farmed, operated laundries, worked in restaurants and hotels, and were employed as domestic servants or farm laborers. In 1878, the city prohibited laundries within the town limits, and, subsequently, a Chinese quarter was established. By the turn of the twentieth century, as many as 600 Chinese lived in Chinatown. Initially, Chinatown was virtually all male. It was composed of shops, boarding houses, gambling parlors, a temple, labor contractors, and other establishments. By 1893, Chinatown had electricity, and it had piped water by 1900. Human waste disposal was managed by construction of backyard latrines. Three artifact-filled latrines were discovered during excavations. They were located on property purchased by California-born Wong Nim in 1900. Wong Nim was born in Alameda County, California, and moved to San Bernardino about 1875. He was successful. He first worked as a laundryman but eventually opened a mercantile shop and acted as a labor contractor. He also opened a temple. Wong remained on the corner of Third and B Streets until his death at age 89 in 1941. At that time, he had earned the honorary title of ‘‘Mayor of Chinatown.’’ When the State of California purchased Wong Nim’s property in 1943, all of the remaining buildings on his property were demolished. At least 1 latrine (number 1035) was filled at this time with debris from the abandoned buildings. The privies were used by people who built residences and businesses on Wong’s original property. However, Wong’s house, store, and temple were located a half block away from the latrines and associated houses. It is possible that the latrines were communally used by several Chinese households and businesses. Processing of the latrine sediment samples was done in 2001, following the methods of Reinhard et al. (1986), Warnock and Reinhard (1992), and Sianto et al. (2005). Sediment was removed from each sample bag. The sediment was freed of large fragments of detritus. From the loose sediments, 30 ml were removed. Next, 3 Lycopodium sp. spore tablets were added to each 30-ml sample (about 1,250 Lycopodium sp. spores were added to each ml of sediment). For this analysis, Lycopodium sp. spore batch 212761 was used. Previous analysis has shown that 12,500 spores are present in each tablet (values presented from different analyses of tablets are 12,432, 12,489, and 12,542). The tablets were dissolved in a few drops of hydrochloric acid in 300-ml beakers. Next, the 30-ml aliquots of sediment were added to the beakers with 50 ml of distilled water. Subsequently, 20 ml of 10% hydrochloric acid in distilled water was added to dissolve calcium carbonates in the sediment. More water was added until the reaction between the acid and the carbonates in the sediment stopped. Once the calcium carbonates were dissolved, the samples were treated with the swirl technique. The contents of the beaker were swirled until all particles were in suspension. The beaker was placed on a flat surface for 30 sec. After 30 sec, the fluid was poured through a 300m mesh. This was repeated twice. The macrofossils on the mesh were examined for night-soil indicators, especially the presence of Rubus sp. seeds. Next, the screened fluid was concentrated by centrifugation in 50-ml centrifuge tubes. The sediments were washed 3 times in distilled water. Preliminary microscopic examinations were made of the samples to determine if further chemical processing was necessary. It was found that the high content of fine silicates required further processing, so 20 ml of 40% hydrofluoric acid were added to each tube, and the sediments were thoroughly mixed in the acid. The samples were left in the hydrofluoric acid for 24 hr and were stirred occasionally during this period. Next, the sediments were concentrated by centrifugation. The acid was replaced by water, and the sediments were reexamined. The vast majority of silicates were dissolved, and microscopic examination was deemed to be possible. The sediments in the tubes were then washed 3 times in distilled water. Drops of the sediments were transferred to glass microscope slides with Pasteur pipettes. The sediment drops were mixed with glycerin and cover-slipped. For each sample, a total of 25 Lycopodium sp. spores was counted along with all parasite eggs found in the process of counting the spores. A count of 25 spores represents 0.02 ml of the sediment sample. After counting, at least 3 more microscope preparations were counted to assess the presence of trace amounts of parasite eggs. We quantified the parasite eggs for 0.02 ml of processed sediment for each sample in order to standardize the results of each analysis in terms of parasite eggs per ml of sediment. For latrine contexts, we found that 0.02 ml is sufficient to identify parasite egg quantities as low as 50 eggs per ml. We then scanned an additional 0.06 to 0.08 ml of processed sediment to identify trace amounts of parasite eggs. The concentrations of eggs of each species were calculated using the following formula: concentration [( p/m) a]/v, where p is parasite eggs counted, m is marker Lycopodium sp. spores counted, a is marker Lycopodium sp. spores added, and v is volume of sediment. Identification of the species of the parasite eggs was done by morphological analysis. In the case of trichurid eggs, the dimensions of the eggs were taken and compared to those of trichurid species from a variety of hosts, including humans, domestic animals, and rodents that commonly infest habitations, outbuildings, and yards. Operculated eggs ?1