Updates on parasite infection prevalence in the Joseon period based on parasitological studies of human coprolites isolated from archaeological sites in the cities of Euijeongbu, Gumi, and Wonju

Article information

Parasites Hosts Dis. 2023;61(1):89-93

Publication date (electronic) : 2023 February 22

doi : https://doi.org/10.3347/PHD.22129

Chang Seok Oh¹, Jong-Yil Chai², Sori Min³, Kyong Taek Oh⁴, Jeonghwan Seol⁵, Mi Kyung Song⁶, Dong Hoon Shin^7,, Min Seo^8,

¹Department of Mortuary Science, College of Bio-convergence, Eulji University, Seongnam 13135, Korea

²Department of Tropical Medicine and Parasitology, Seoul National University College of Medicine, Seoul 03080, Korea

³Nuri Institute of Archaeology, Gongju 32587, Korea

⁴Sudo Institute of Cultural Heritage, Seoul 03714, Korea

⁵Sejong Research Institute of Cultural Heritage, Gyeongsan 41533, Korea

⁶Department of Fashion Design and Marketing, Seoul Women’s University, Seoul 01797, Korea

⁷Institute of Forensic and Anthropological Science, Seoul National University College of Medicine, Seoul 03080, Korea

⁸Department of Parasitology, Dankook University College of Medicine, Cheonan 31116, Korea

^*Correspondence (sdh, cuteminjae@gmail.com; sm, bbbenji@naver.com)

Received 2022 September 22; Accepted 2022 December 15.

Studying ancient parasite eggs remaining in archaeological samples (e.g., coprolites) can reveal the infection pattern of specific parasites throughout history. Over the past decade, we performed parasitological investigations using feces (coprolite) samples from the mummies of the Joseon period. A series of such studies led to the identification of various parasite species [1]. These data provided an essential basis for estimating the parasite infection rate during the Joseon period. In brief, we compared the data obtained from parasitological studies on Joseon mummies (n=24) and those obtained from the South Korean national survey of 1971 [1]. The estimated parasite infection rates in Joseon mummies were 58.3% for Ascaris lumbricoides, 83.3% for Trichuris trichiura, 25% for Clonorchis sinensis, and 33.3% for Paragonimus westermani [1]. On the other hand, in the 1971 study, the infection prevalence was 54.9, 65.4, 4.6, and 0.09% for A. lumbricoides, T. trichiura, C. sinensis, and P. westermani, respectively. Thus, archaeoparasitological studies enable the estimation of changing patterns of parasitic infection rates in Korean people throughout history [1,2].

Our work on Joseon period samples has great academic significance. Therefore, this kind of research needs to be pursued, especially because only 24 cases have been investigated so far. In this regard, we should thoroughly examine more coprolite samples from newly discovered Korean mummies. By updating the data with new Joseon period cases, we can more accurately estimate the parasite infection rate in premodern Korean society.

Recently, we examined parasites in the coprolites from 4 Joseon period individuals recovered during archaeological excavations in the cities of Euijeongbu (Gyeonggi-do), Gumi (Gyeongsangbuk-do), and Wonju (Gangwon-do) (Fig. 1). The archaeological information related to each case is summarized in Table 1.

Fig. 1

Organic materials precipitated on the pelvic or abdominal regions of the 4 human remains examined in the present study. (A) Wonju6-1, (B) Euijeongbu-1, (C) Euijeongbu-2, and (D) Gumi-2 cases. *Indicate the sampling location for the archaeoparasitological analysis.

Table 1

The information on Joseon period human remains examined in this study and archaeoparasitological data

Microscopic analyses were performed on coprolites or pelvic bone sediments collected from fully or half-mummified Joseon period human remains. Specimens (0.5–4 g) were rehydrated in trisodium phosphate solution (0.5%) [3,4]. They were filtered through a mesh, precipitated, and dissolved in a trisodium phosphate solution (0.5%, 20 ml). The solution was dropped on slides for observations under a BH-2 light microscope (Olympus, Tokyo, Japan). A total of 200 μl was examined for each sample. The size of parasite eggs was measured for each species. The newly obtained data were then compared with those reported previously in the national survey from 1972 to 2019 [5,6].

Microscopic analyses revealed that mummy coprolites comprised the following variety of ancient parasite eggs: T. trichiura in Euijengbu-1 and -2; T. trichiura, A. lumbricoides, and C. sinensis in Gumi-2; and T. trichiura, A. lumbricoides, C. sinensis, and P. westermani in Wonju6-1 (Fig. 2). Average egg sizes are presented in Table 1. Table 2 shows the present and previous data of parasitological examinations (total case number=30). The overall positive infection rates of soil-transmitted helminths during the Joseon period were 86.7% (26/30) for T. trichiura and 56.7% (17/30) for A. lumbricoides. Regarding trematodes, C. sinensis and P. westermani infection rates were estimated to be 30.0% (9/30) and 30.0% (9/30), respectively. Compared with the Joseon period results (n=24) reported by Seo et al. [1], the estimated overall infection rate obtained in the present study is slightly different, albeit the difference is not significant.

Fig. 2

Parasite eggs found in the feces of 4 mummified human remains (Euijeongbu-1, Euijeongbu-2, Gumi-2, and Wonju6-1). Scale bars, 50 μm.

Table 2

Archaeoparasitological results of Korean mummies^a

Since limited information is available on parasite infection patterns in the Joseon period society, studies on Korean mummies are invaluable to parasitologists. Over the last few years, parasitological data on Joseon period mummy coprolites have been reported [2]. The results of the present study provide additional information to re-estimate the parasite infection rate in the Joseon society. Moreover, only a slight difference was observed between the present data and the last estimate of the Joseon period infection rate reported by Seo et al. [1]. Thus, we confirmed the changing pattern of parasite infection prevalence throughout the Joseon period to 21st century in Korea reported by Seo et al. [1]. Briefly, the infection prevalence of the trematodes C. sinensis and P. westermani was lower than that of the nematodes A. lumbricoides and T. trichiura. The trematode infection rates obtained from the data of the 1971 study and those obtained from the Joseon period are very different (26.7 and 4.6% for C. sinensis, respectively, and 33.3% and 0.09% for P. westermani, respectively). In contrast, the nematode infection rates in the Joseon period (83.3% for T. trichiura and 60.0% for A. lumbricoides) remained almost the same until 1971 (65.4% for T. trichiura and 54.9% for A. lumbricoides) but were greatly decreased (0.2% for T. trichiura and 0.3% for A. lumbricoides) in 1992. Various hypotheses have been proposed to explain these historical changes in the rate of parasitic infection [7]; however, none explains it completely so far. Further research and discussion are needed to accurately comprehend this subject.

Analyzing parasite infection during the Joseon period and comparing it with the 20th century national survey data provide remarkable insights into historical parasitism in premodern Korean society that could not be obtained using conventional research. In this regard, periodical updates with newly discovered cases provide supplementary information that further reinforces the reliability of our data on Joseon parasite infection. The present study analyzed newly discovered mummy coprolites and confirmed the human parasite infection rates in the Joseon society estimated previously by examining mummy coprolites.