Ectopic paragonimiasis from 400-year-old female mummy of Korea

Of the parasite eggs discovered in ancient samples from Korean archaeological sites, Paragonimus spp. are of particular importance in that they are regarded as one of the most insidious trematode infection sources. Although their infection prevalence decreased rapidly in the early 20th century, archaeoparasitological studies on the species are still required, as historical knowledge of paragonimiasis remains far from comprehensive. Fortunately, we recently were given a chance to examine a medieval Korean mummy in a good state of preservation. Using morphological techniques, we discovered evidence of ectopic paragonimiasis in the sample from the 17th-century female. When the ITS 2 gene was extracted, amplified and sequenced from Paragonimus eggs, it showed 100% homology to the sequences of modern Paragonimus westermani reported from Korea and Japan, forming a cluster distinct from South Asian P. westermani. Our report is the first-ever analysis of ancient Paragonimus DNA from any archaeological field in the world. The ectopic paragonimiasis diagnosis made in this study, especially involving the liver sample, also is the first of its kind in archaeoparasitology.     

A parasitological paradox: Why is ascarid infection so rare in the prehistoric Americas?

Ascaris lumbricoides (giant roundworm) and Trichuris trichiura (whipworm) are the most common intestinal parasites found in humans worldwide today and they almost always co-occur. However, we find two distinct patterns in archaeological material. In historical North American and Old World contexts, the association of A. lumbricoides and T. trichiura is similar to the modern epidemiological picture. In contrast, the co-occurrence of A. lumbricoides and T. trichiura eggs in prehistoric South America is rare. For prehistoric contexts, T. trichiura is the most common parasite found in archaeological material. Recently molecular biology techniques pointed to a subdiagnosis of roundworm infection in pre-Columbian South American populations. This is contrary to the modern epidemiological picture in which A. lumbricoides infection is predominant. This is a paradox, especially when one considers the number of eggs laid by female daily, 200,000 and 20,000 thousand per day, for A. lumbricoides and T. trichiura respectively. By reviewing the records of these parasites, this paradox is presented and explanations for the paradox are explored. Taphonomy, prehistoric behavior patterns and medicinal plant use seem to be most relevant to the explanation of the paradox. Nematophagous fungi is a less likely factor creating the near absence of A. lumbricoides eggs in the prehistoric New World.     

Clarifying prehistoric parasitism from a complementary morphological and molecular approach

This paper reports an approach to the identification of prehistoric parasitic infection, which integrates traditional morphological methods with molecular methods. The approach includes the strengths of each method while mitigating the limitations. Demonstrating the efficacy of this approach, we provide a case study from a 1400 year old desiccated fecal sample from La Cueva de los Muertos Chiquitos, archaeological site, near Rio Zape, Durango, Mexico. Traditionally prepared microscope slides were processed via microscopy and tentative ascarids were identified. Information regarding the parasites' developmental stage was recorded. DNA was then extracted directly from the slide material. From this DNA extract, a small segment of the 18S ribosomal RNA gene variant that is specific to Ascaris, and its phylogenetically close relatives, was targeted for PCR amplification and sequencing. Phylogenetic analysis of the DNA sequence best matched a member of physalopterids, rather than ascarids, with a single exception of a match to Contracaecum spiculigerum. Subsequent extractions, amplifications and sequencing of the original rehydrated coprolite material confirmed these results. The C. spiculigerum sequence represented a phylogenetic anomaly and subsequent analysis determined the sequence was an error in the BLAST database, likely attributable to misidentification of juvenile specimens prior to sequencing and submission. Physaloptera are a difficult genus to identify morphologically and can carry major health burdens. They may be underreported in humans, in part, because of morphological similarities to the more common human parasites belonging to ascarids. We conclude that integrating traditional morphological methods with molecular methods can help resolve this issue, in both contemporary and prehistoric populations.