Epidemiology and clinical characteristics of classic Kaposi's sarcoma, seroprevalence, and variants of human herpesvirus 8 in South America: a critical review of an old disease.

OBJECTIVE: To review the current South American literature on classic Kaposi's sarcoma (KS) and human herpesvirus 8 (HHV-8), and point the way for studies that still need to be performed. MATERIALS AND METHODS: The authors performed an exhaustive search in LILACS, SCIELO and PUBMED databases for classic KS and HHV-8 in South America. The relevant material was evaluated and reviewed. RESULTS: More than 250 cases have been reported with three big case series (Argentina, Colombia and Peru). The classic KS form seen in Colombia resembles the type of disease seen among African communities; the same unusual presentation with confluent exophytic nodules or eroded lesions has been noticed in Peru. Low rates of HHV-8 antibodies have been found in blood donors from Chile, Argentina and Brazil (3%, 4%, 2.8-7.4%, respectively); whereas high rates of HHV-8 antibodies have been found in Amerindians from Brazil and Ecuador. Five specimens from Argentina were subtyped: (three classic KS and two AIDS KS); the identified strains fell into subtypes A and C. AIDS-related KS specimens from Brazil and Venezuela were subtyped: (43 and nine respectively); analysis grouped them predominantly into subgroups A, B and C. A new HHV-8 subtype E was found endemic in Brazilian and Ecuadorian Amerindians. In French Guiana ten endemic KS and six AIDS-related KS specimens were subtyped; analysis grouped them predominantly into subgroups A, B and C. CONCLUSION: Classic KS in South America has a very similar clinical presentation but not the same as the classic KS variety described in the Mediterranean. Initial seroprevalence studies performed in the general population and in blood donors showed low seroprevalence of HHV-8, whereas high seroprevalence rates were seen in Amerindian population. The existing serological assays, nonetheless, need to be further refined, and new assays need to be developed. Finally, the key to understanding the precise molecular epidemiology and phylogenetic distribution of HHV-8 in South America would be to perform more subtyping of classic KS cases.     

Fasciola hepatica phenotypic characterization in Andean human endemic areas: valley versus altiplanic patterns analysed in liver flukes from sheep from Cajamarca and Mantaro, Peru

Fascioliasis is a zoonotic parasitic disease caused by Fasciola hepatica and Fasciola gigantica. Of both species, F. hepatica is the only one described in the Americas, mainly transmitted by lymnaeid snail vectors of the Galba/Fossaria group. Human fascioliasis endemic areas are mainly located in high altitude areas of Andean countries. Given the necessity to characterize F. hepatica populations involved, the phenotypic features of fasciolid adults infecting sheep present in human fascioliasis endemic areas were analysed in the Cajamarca Valley and Mantaro Valley (valley transmission patterns) and the northern Bolivian Altiplano (altiplanic transmission pattern). A computer image analysis system (CIAS) was applied on the basis of standardized measurements. The aforementioned highland populations were compared to standard lowland natural and experimental populations of European origin. Liver fluke size was studied by multivariate analyses. Two phenotypic patterns could be distinguished in F. hepatica adult size: the valley pattern (Cajamarca and Mantaro, Peru) and the altiplanic pattern (northern Altiplano, Bolivia). Results showed that the Andean valley population and European standard populations presented a phenotypic homogeneity. The Altiplano population showed a large size range with a pronouncedly lower minimum size indicating that uterus gravidity is reached at a smaller size than in valley populations. The results of this study demonstrate that there is no apparent relationship between the shape of fasciolid adults with regard to altitudinal difference or geographical origin and that allometry-free shape appears as a more stable trait than size in fasciolid species. Results are analysed in terms of intensity/crowding effect aspects and permanent/seasonal transmission characteristics.     

Evidence of tungiasis in pre-Hispanic America

Ancient parasites of the genus Tunga originated in America and, during the first half of the 19th century, were transported to the Eastern Hemisphere on transatlantic voyages. Although they were first documented by Spanish chroniclers after the arrival of Columbus, little is known about their presence in pre-Hispanic America. To evaluate the antiquity of tungiasis in America, we assessed several kinds of early documentation, including written evidence and pre-Incan earthenware reproductions. We identified 17 written documents and 4 anthropomorphic figures, of which 3 originated from the Chimu culture and 1 from the Maranga culture. Tungiasis has been endemic to Peru for at least 14 centuries. We also identified a pottery fragment during this study. This fragment is the fourth representation of tungiasis in pre-Hispanic America identified and provides explicit evidence of disease endemicity in ancient Peru.     

Poly-Ig tandems from I-band titin share extended domain arrangements irrespective of the distinct features of their modular constituents

The cellular function of the giant protein titin in striated muscle is a major focus of scientific attention. Particularly, its role in passive mechanics has been extensively investigated. In strong contrast, the structural details of this filament are very poorly understood. To date, only a handful of atomic models from single domain components have become available and data on poly-constructs are limited to scarce SAXS analyses. In this study, we examine the molecular parameters of poly-Ig tandems from I-band titin relevant to muscle elasticity. We revisit conservation patterns in domain and linker sequences of I-band modules and interpret these in the light of available atomic structures of Ig domains from muscle proteins. The emphasis is placed on features expected to affect inter-domain arrangements. We examine the overall conformation of a 6Ig fragment, I65–I70, from the skeletal I-band of soleus titin using SAXS and electron microscopy approaches. The possible effect of highly conserved glutamate groups at the linkers as well as the ionic strength of the medium on the overall molecular parameters of this sample is investigated. Our findings indicate that poly-Ig tandems from I-band titin tend to adopt extended arrangements with low or moderate intrinsic flexibility, independently of the specific features of linkers or component Ig domains across constitutively- and differentially-expressed tandems. Linkers do not appear to operate as free hinges so that lateral association of Ig domains must occur infrequently in samples in solution, even that inter-domain sequences of 4–5 residues length would well accommodate such geometry. It can be expected that this principle is generally applicable to all Ig-tandems from I-band titin.     

Case Report: An Ectopic Case of Tunga spp. Infection in Peru

Tungiasis is a neglected ectoparasitism of impoverished areas in South America and sub-Saharan Africa. The sand flea Tunga spp. preferably infests the soles and the periungueal and interdigital regions of the feet. Ectopic tungiasis is rare, even in highly endemic areas. We describe a case of an indigenous patient in Peru who presented with a nodular lesion in the extensor aspect of the knee and whose biopsy was compatible with Tunga spp. This is the first documented case of knee tungiasis in an endemic country. The historical, clinical, histological, and current epidemiological aspects of tungiasis in Peru are discussed here.     

Plants used by native Amazonian groups from the Nanay River (Peru) for the treatment of malaria

Aim of the study

In order to evaluate the antimalarial potential of traditional remedies used in Peru, Indigenous and Mestizo populations from the river Nanay in Loreto were interviewed about traditional medication for the treatment of malaria.

Materials and methods

The survey took place on six villages and led to the collection of 59 plants. 35 hydro-alcoholic extractions were performed on the 21 most cited plants. The extracts were then tested for antiplasmodial activity in vitro on Plasmodium falciparum chloroquine resistant strain (FCR-3), and ferriprotoporphyrin inhibition test was also performed in order to assume pharmacological properties.

Results

Extracts from 9 plants on twenty-one tested (Abuta rufescens, Ayapana lanceolata, Capsiandra angustifolia, Citrus limon, Citrus paradise, Minquartia guianensis, Potalia resinífera, Scoparia dulcis, and Physalis angulata) displayed an interesting antiplasmodial activity (IC₅₀ < 10 μg/ml) and 16 remedies were active on the ferriprotoporphyrin inhibition test.

Conclusions

The results give scientific validation to the traditional medical knowledge of the Amerindian and Mestizo populations from Loreto and exhibit a source of potentially active plants.