37 research outputs found

    Taphonomic considerations on pinworm prevalence in three Ancestral Puebloan latrines

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    For archaeological studies it is always necessary to consider taphonomic factors that could have influenced in ancient material preservation. Parasite eggs are usually highly degraded in ancient sites dated from all periods of time and taphonomic factors are mentioned to explain absence and low quantity of eggs found. In this study, we compare parasite egg recovery of three Great House latrines: two from Aztec Ruins (Rooms 219 and 225) and one from Salmon Ruins. We compared through statistical regression the recovery of eggs with the abundance of two classes of decomposers: mites and nematodes. These microorganisms have relation with nematode larvae and parasites remains degradation, respectively, mostly in moist environments. Pinworm was the only parasite found in the sites studied. Prevalences were 32.8% at Salmon Ruins, 72.7% at Aztec Ruins Room 225 and 14.3% at Room 219. Egg preservation was considered good at Salmon Ruins and Aztec Ruins Room 225. At Room 219, the eggs were badly preserved and there was a significant statistical correlation with mites (multiple r (18) =0.64/P=0.002). This correlation could indicate that mites could be involved in preservation, and consequently that pinworm prevalence in this latrine is underestimated. Abiotic factors such as humidity could have possibly favored the biological relation. Considering the extreme egg degradation at Room 219, it is not possible to strictly compare parasite data with other Ancestral Pueblo sites, even with Room 225, located at the same site. Room 225 prevalence is the highest found in Ancestral Pueblo sites until now. Taphonomic analysis shows that decomposers operated at different levels of severity, despite the latrines\u27 close location

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

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    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

    Enterobius vermicularis: Ancient DNA from North and South American Coprolites

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    A molecular paleoparasitological diagnostic approach was developed for Enterobius vermicularis. Ancient DNA was extracted from 27 coprolites from archaeological sites in Chile and USA. Enzymatic amplification of human mtDNA sequences confirmed the human origin. We designed primers specific to the E. vermicularis 5S ribosomal RNA spacer region and they allowed reproducible polymerase chain reaction identification of ancient material. We suggested that the paleoparasitological microscopic identification could accompany molecular diagnosis, which also opens the possibility of sequence analysis to understand parasite-host evolution

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

    Get PDF
    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

    Genetic Characterization of Human T-Cell Lymphotropic Virus Type 1 in Mozambique: Transcontinental Lineages Drive the HTLV-1 Endemic

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    Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of Adult T-Cell Leukemia/Lymphoma (ATL), the Tropical Spastic Paraparesis/HTLV-1-associated Myelopathy (TSP/HAM) and other inflammatory diseases, including dermatitis, uveitis, and myositis. It is estimated that 2–8% of the infected persons will develop a HTLV-1-associated disease during their lifetimes, frequently TSP/HAM. Thus far, there is not a specific treatment to this progressive and chronic disease. HTLV-1 has means of three transmission: (i) from mother to child during prolonged breastfeeding, (ii) between sexual partners and (iii) through blood transfusion. HTLV-1 has been characterized in 7 subtypes and the geographical distribution and the clinical impact of this infection is not well known, mainly in African population. HTLV-1 is endemic in sub-Saharan Africa. Mozambique is a country of southeastern Africa where TSP/HAM cases were reported. Recently, our group estimated the HTLV prevalence among Mozambican blood donors as 0.9%. In this work we performed a genetic analysis of HTLV-1 in blood donors and HIV/HTLV co-infected patients from Maputo, Mozambique. Our results showed the presence of three HTLV-1 clusters within the Cosmopolitan/Transcontinental subtype/subgroup. The differential rates of HIV-1/HTLV-1 co-infection in the three HTLV-1 clusters demonstrated the dynamic of the two viruses and the need for implementation of control measures focusing on both retroviruses
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