Human intestinal parasites in Subsaharan Africa. II. Sao Tomé and Principe

In 1983 the authors carried out a survey in the Democratic Republic of S?o Tomé and Principe, analysing 1050 specimens of stools collected among the population from apparently healthy subjects chosen at random and in a number proportional to the distribution of the population in the regions of the country (about 1% of the population was examined). The examined subjects were divided into 3 age groups (0-3, 4-12, more than 12 years old), to have homogeneous groups in relation principally to modalities of life and nutritional patterns. There were 488 male subjects and 562 females. The survey was preceded by a sensitization of the people to the problem of intestinal parasites and by two preliminary surveys about the number of existing latrines and about people's believes and attitudes in relation to helmintiasis. The tests were made according to the modified Ritchie technique on fecal specimens preserved with 10% formol solution. The following results were found: a) Protozoa: Entamoeba coli, 43.0%; Iodamoeba buetschlii, 9.0%; Giardia intestinalis, 8.8%; Endolimax nana, 7.0%; E. histolytica, 5.5%; E. hartmanni, 2.5%; Chilomastix mesnili, 2.3%; Trichomonas intestinalis, 0.2%; Balantidium coli, 0.1%. b) Helminths: Trichuris trichiura, 87.7%; Ascaris lumbricoides, 64.3%; Ancylostomatidae, 40.5%; Strongyloides stercoralis, 6.8%; Hymenolepis diminuta, 0.3%; H. nana, 0.2%; Schistosoma haematobium, 0.2%. In 28.2% of the specimens (with more than 50% of subjects in some villages) eggs of Heterophyidae were found, very similar to Metagonimus yokogawai, but not yet identified by us, with the following characteristics: elliptical shape, average size 25 mu (22.2-27.7) X 18.5 mu (17-21), thick wall, operculum difficult to see, not sticking out from the outline but visible by focusing being in a different refractiveness, presence of a small polar knob, colour slightly brownish, asymmetric miracidium. Further investigations are necessary to identify the species of this trematode and to understand if it is a true human parasite or a pseudoparasite. The general results show the existence of a heavy fecal pollution all over the territory of the D.R. of S?o Tomé and Principe, connected with unhygienic life conditions, dangerous for health. This suggests to start urgently a sanitation program.     

Human enzyme polymorphism in the Canary Islands. III. Tenerife Island population

We analyzed the genetic polymorphism of eight red cell enzymes in samples from different geographical areas of Tenerife and the Iberian peninsula. The gene frequency heterogeneity found within the Tenerife samples was at the same level as that of Tenerife-mainland comparisons. The presence of the Negroid G6PD A+ allele in the Tenerife samples is evidence of an African admixture with a mean estimation of 4.5%.     

Multidimensional scaling and the analysis of human biological diversity in Subsaharan Africa

Much information concerning intergroup variation in Subsaharan Africa has been collected by Hiernaux, who has calculated measures of biological distance (Δg) between pairs of 101 African human populations. The resulting very large matrix of distances is not easily interpreted through simple inspection. Therefore non-metric multidimensional scaling is here applied in order to produce a configuration of 60 selected groups in a space of reduced dimensionality. A three dimensional solution shows acceptable stress, and this map of populations is used to support and extend Hiernaux's earlier conclusions.     

Human intestinal parasites in the past: new findings and a review

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.     

Trichodinid (Ciliophora; Peritricha) gill parasites of freshwater fish in South Africa

Summary Trichodinella epizootica (Raabe, 1950) and seven new species of trichodinid ectoparasites (Ciliophora: Peritricha) were identified from both wild and pond fishes collected during an extensive survey of fish ponds, rivers and lakes in the Transvaal, South Africa. The new species are Tripartiella clavodonta n. sp., T. lechridens n. sp., T. leptospina, n. sp., T. macrosoma n. sp., T. nana n. sp., T. orthodens n. sp. and Trichodinella crennulata n. sp.     

Morbidity, due to schistosomiasis mansoni, and its control in Subsaharan Africa

The measuring and monitoring of morbidity are essential components of schistosomiasis control programmes. Bruno Gryseels and Anton Polderman assess the objectives, difficulties and importance of morbidity control of schistosomiasis mansoni in subsaharan Africa.     

Blood and intestinal parasites of squirrels (Rodentia: Sciuridae) in Amazonian Brazil

We report the result of an examination for blood and intestinal protozoa in 12 specimens of the red squirrel Sciurus spadiceus (Rodentia: Sciuridae) from Birroque, municipality of Placido de Castro, state of Acre, Brazil. No parasites were detected in thin, Giemsa-stained blood films of the animals, but culture of the blood of three in Difco B45 medium blood-agar slants gave rise to isolates of epimastigotes. Inoculation of one isolate into laboratory mice resulted in the appearance of Trypanosoma cruzi-like trypomastigotes in their peripheral blood, and the other two isolates gave rise to transient infections with a T. lewisi-like parasite in inoculated mice and hamsters. The failure of the latter parasite to develop in the triatomine bug Rhodnius robustus suggests that it is probably not T. rangeli. This appears to be the first record of a T. lewisi-like trypanosome in neotropical squirrels. Oocysts of an Eimeria sp., were detected in the faeces of 10 animals (83.3%). The parasite develops in the epithelial cells of the intestine, where it may cause severe damage and sometimes results in death of the animal. No oocysts were detected in bile.     

Cryptic speciation among intestinal parasites (Trematoda: Digenea) infecting sympatric host fishes (Sparidae)

In the north‐western (NW) Mediterranean, the teleosts Diplodus sargus, D. vulgaris and D. annularis coexist in infralittoral habitats. These fishes are infected by two species of the Digenea (Platyhelminthes, Trematoda): Macvicaria crassigula (Opecoelidae) and Monorchis parvus (Monorchiidae) for which we obtained Internal Transcribed Spacer rDNA sequences. Each parasite species represents a complex of two cryptic species, one restricted to D. annularis, and the other shared by D. sargus and D. vulgaris. Cytochrome b mtDNA sequences were used to infer host phylogenetic relationships which showed that the distribution of parasites in Diplodus hosts is not a consequence of coevolutionary interactions. We used diet analyses available for the fish hosts to assess the degree of overlap in the use of food among the three species. The feeding overlap was significant only between D. sargus and D. vulgaris, but not for the other fish pairs. The possible mechanisms involved in the speciation of the digenean fauna of Diplodus fishes are discussed.     

Helminth parasites of unisexual and bisexual whiptail lizards (Teiidae) in North America. III. The Chihuahuan spotted whiptail (Cnemidophorus exsanguis)

Twenty-four of 87 (28%) parthenogenetic Chihuahuan spotted whiptails (Cnemidophorus exsanguis) from nine counties of New Mexico and seven counties of Texas were infected with one or more endoparasites. These included a linstowiid cestode (Oochoristica bivitellobata) in seven (8%), a larval spirurid nematode (Physaloptera sp.) in nine (10%) and an oxyurid nematode (Pharyngodon warneri) in 10 (11%). This note, the third in a series of reports on helminths of Cnemidophorus spp., documents parasites in C. exsanguis for the first time.     

Parasites of Salmo trutta L. from the Titino River. Part III. Histological observations of parasites of the intestinal tract

During researches on helminth parasites of Salmo trutta L. from the River Tirino (L'Aquila - Italy) histological studies of the intestinal tract of brown trout infected by the following species: Crowcrocaecum testiobliquum (Wisnewski, 1932) Skrjabin e Koval, 1956; Cyathocephalus truncatus (Pallas, 1781);o Truttaedacnitis truttae (Fabricius, 1794) Petter, 1974 and Dentitruncus truttae Sinzar, 1955 have been carried out. The attachment of the single species and the histological changes in the host gut due to parasite species have been described.     

Nematode parasites of the turtle Pelusios sinuatus (pelomedusidae: Pleurodira) from southern Africa

Summary Two nematode parasites are described from the turtle Pelusios sinuatus of southern Africa. Camallanus chelonius n. sp. (Camallanoidae) is easily distinguished from other species reported from Africa in possessing less than 10 smooth ridges in the buccal valves. It most closely resembles a group of seven species described from Indian amphibians but may be differentiated from these by a combination of characters: shape of the female tail and distal end of the spicules, male caudal papillae, presence or absence of small barbs between the bases of the buccal valve ridges. C. chelonius is intermediate in cephalic morphology between other Camallanus spp., which are all restricted to fish and amphibian hosts, and the genus Serpinema reported only in turtles. Falcaustra pelusios n.sp. (Cosmocercoidea) is the first species of the genus reported in pelomedusid turtles. It is easily distinguished from all other species by the presence of two large and complex cheilostomal rings in the cephalic end, a very short male tail, large gubernaculum, relatively short thick spicules and large number (more than 50 pairs) of subventral preanal muscle cells posterior to the sucker. ac]19810907     

Urinary schistosomiasis on Pemba Island: low-cost diagnosis for control in a primary health care setting

In the 1970s and early 1980s indirect diagnosis of urinary schistosomiasis, using urinalysis reagent strips for proteinuria and haematuria, was proposed as a possible alternative to the more accurate but very time-consuming parasitological methods. The recent experience o f the Schistosomiasis Control Programme for Pemba Island, which used a combination of (1) observations o f grossly bloody urine specimens, (2) results from reagent strips for measuring haematuria, and (3) treatment with praziquantel, is the first large-scale example o f a simple, inexpensive and promising alternative for controlling the morbidity caused by this parasite.