Almost all known human specific
parasites have been found in ancient feces. A review of the paleoparasitological
helminth and intestinal protozoa findings available in the literature is presented.
We also report the new paleoparasitologic findings from the examination performed
in samples collected in New and Old World archaeological sites. New finds of ancylostomid,
Ascaris lumbricoides
,
Trichuris trichiura
,
Enterobius vermicularis
,
Trichostrongylus
spp.,
Diphyllobothrium latum
,
Hymenolepis nana
and Acantocephalan eggs are reported. According to the findings, it is probable
that
A. lumbricoides was originally a human parasite. Human ancylostomids,
A. lumbricoides and
T. trichiura, found in the New World in pre-Columbian
times, have not been introduced into the Americas by land via Beringia. These
parasites could not supported the cold climate of the region. Nomadic prehistoric
humans that have crossed the Bering Land Bridge from Asia to the Americas in the
last glaciation, probably during generations, would have lost these parasites,
which life cycles need warm temperatures in the soil to be transmitted from host
to host. Alternative routes are discussed for human parasite introduction into
the Americas.
