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E Pozio

Publications and source records attributed to E Pozio.

At least 37 records · Page 2Linked to original sources
PubMed2005

Recent advances on the taxonomy, systematics and epidemiology of Trichinella.

Since Owen first described Trichinella as a human pathogen in 1835, the number of organisms comprising this genus has grown dramatically. Where it was once thought to be a monospecific group, this genus is now comprised of eight species and three additional genotypic variants that have yet to be taxonomically defined. Along with the growth in the genus and description of the parasites has come a concomitant increase in our understanding of the epidemiology and geographical distribution of these organisms. Recent expansion of the non-encapsulated group to include three species biologically defined by their unique host ranges encompassing mammals, birds and reptiles, has raised substantial questions as to the term, 'Trichinella-free' as it applies to geographical localities. A true appreciation of the adaptability of this genus to host and environmental selection factors, as well as its dissemination to the far reaches of the world can best be appreciated by reviewing what we know and what we hope to know about this ancient and elusive parasite. The review herein consolidates our current understanding of the taxonomy, epidemiology, and phylogeny of the genus Trichinella, and identifies areas where data are lacking and our knowledge requires additional clarification.

Animals↗
PubMed2005

Dientamoeba fragilis is more prevalent than Giardia duodenalis in children and adults attending a day care centre in Central Italy.

Giardia duodenalis is a well recognised enteropathogen, while Dientamoeba fragilis is rarely detected and consequently it is not recognised as an important human pathogen. In 2002-2003, a survey has been carried out on enteroparasites in faecal samples of outpatients attending a day care centre in the town of Perugia (Central Italy). To improve the detection level, at least three samples from each patient were collected at different days and within two hours from defecation. The coproparasitological examination has been carried out by direct microscopic examination, faecal concentration, and Giemsa and modified Ziehl-Nielsen stainings of faecal smears. The genotypes of Giardia duodenalis isolates were determined by PCR of the beta-giardin gene. Of 1,989 enrolled people (966 children, 1,023 adults), 165 persons (8.3%; 153 adults, 15.0%; 12 children, 1.2%), were positive for parasites, but only 1 12 adults (73.2% of those infected) and eight children (66.7% of those infected) harboured D. fragilis and G. duodenalis. Both the Assemblages A and B were detected in 18 G. duodenalis isolates examined at the beta-giardin gene. The higher prevalence of D. fragilis infections than that of G. duodenalis is probably related to the method used, a procedure, which is rarely followed in laboratories for the diagnosis of enteric parasites. These epidemiological data suggest that when faecal samples are examined after a period of time and without Giemsa staining, most D. fragilis infections goes undetected.

Adolescent↗
PubMed2005

Infection with human immunodeficiency virus, herpes simplex virus type 2, and human herpes virus 8 in remote villages of southwestern Papua New Guinea.

To investigate the spread of human immunodeficiency virus (HIV) and other sexually transmitted viruses, two serosurveys (the first in 1999 among 56 adults and the second in 2001 among 351 adults) were conducted in remote villages of the southwestern part of Papua New Guinea. Only one individual was positive for antibodies to HIV. In 2001, the seroprevalence of human herpes virus 8 (HHV-8) was 32.2%, and the seroprevalence of herpes simplex virus type 2 (HSV-2) was 27.4%. Both prevalence rates increased with age, and were lower in the villages near the Bensbach River. The seropositivity of HSV-2 was independently correlated with HHV-8 infection. Our data show that the inhabitants of the southwestern region of Papua New Guinea currently experience an extremely low circulation of HIV. However, the high prevalence of infectious agents that can be sexually transmitted, such as HSV-2 and to a lesser extent HHV-8, indicates the presence of behavioral patterns that may facilitate the spread of HIV in this area of currently low endemicity.

HIV↗
PubMed2005

Human trichinellosis due to Trichinella britovi in southern France after consumption of frozen wild boar meat.

Six patients were infected with Trichinella britovi in southern France following consumption of frozen wild boar meat, which had been frozen at -35 degrees C for 7 days. Microscopic examination of a sample of frozen wild boar muscle revealed the presence of rare encapsulated Trichinella larvae, identified as T. britovi. People eating wild boar must follow individual prophylactic rules such as efficient cooking of meat (at least 65 degrees C at the core for 1 minute) as recommended by the International Commission on Trichinellosis, or freezing exceeding four weeks at -20 degrees C.

Animals↗
PubMed2004

First record of Trichinella pseudospiralis in the Slovak Republic found in domestic focus.

Infection of Trichinella spp. is widespread among wildlife in Slovakia and the red fox (Vulpes vulpes) is the main reservoir of Trichinella britovi. Trichinella spiralis has been rarely documented in sylvatic and domestic animals of this country. During routine examination of domestic pigs at the slaughter, Trichinella larvae were detected by artificial digestion in a domestic pig of a large-scale breeding farm in Eastern Slovakia. The parasite has been identified by molecular (PCR) and biochemical (allozymes) analyses and by the morphology of the nurse cell as the non-encapsulated species Trichinella pseudospiralis infecting both mammals and birds. The epidemiological investigation carried out at the farm level revealed the presence of the same parasite species in other three pigs of 192 examined (2.1%), in 3 of 14 (21.4%) examined synanthropic rats (Rattus norvegicus) and in a domestic cat. The farm was characterized by inadequate sanitary conditions, insufficient nutrition, cannibalism and the presence of rat population. A different profile has been observed at the phosphoglucomutase locus in T. pseudospiralis isolates from Slovakia in comparison with the T. pseudospiralis reference isolate from the Palearctic region. This is the first documented focus of T. pseudospiralis from Central Europe. The detection in domestic pigs of a non-encapsulated parasite infecting both mammals and birds stresses the need to avoid the use of trichinelloscopy to detect this infection at the slaughterhouse.

Adenylate Kinase↗
PubMed2004

Trichinella pseudospiralis foci in Sweden.

In Sweden, the prevalence of Trichinella infection in domestic pigs has greatly decreased since the 1970s, with no reports in the past 4 years. However, infected wild animals continue to be found. The objective of the present study was to identify the species of Trichinella present in animals of Sweden, so as to contribute to the knowledge on the distribution area and hosts useful for the prevention and control of this zoonosis. In the period 1985-2003, Trichinella larvae were detected in the muscles of 81/1800 (4.5%) red foxes (Vulpes vulpes), 1/6 (16.7%) arctic fox (Alopex lagopus), 1/7 (14.3%) wolf (Canis lupus), 10/200 (5.0%) lynxes (Lynx lynx), 4/8000 (0.05%) wild boars (Sus scrofa), and 27/66 x 10(6) (0.000041%) domestic pigs. All four Trichinella species previously found in Europe were detected (Trichinella spiralis, T. nativa, T. britovi and T. pseudospiralis). The non-encapsulated species T. pseudospiralis was detected in three wild boars from Holo (Stockholm area) and in one lynx from Froso (Ostersund area), suggesting that this species is widespread in Sweden. These findings are consistent with those of a study from Finland, both for the unexpected presence of T. pseudospiralis infection and the presence of the same four Trichinella species, suggesting that this epidemiological situation is present in the entire Scandinavian region. The widespread diffusion of T. pseudospiralis in the Scandinavian region is also important in terms of it potential impact on public health, given that human infection can occur and the difficulties to detect it by the trichinelloscopic examination.

Animals↗
PubMed2004

Trichinella papuae and Trichinella zimbabwensis induce infection in experimentally infected varans, caimans, pythons and turtles.

The discovery of Trichinella zimbabwensis in farm crocodiles of Zimbabwe has opened up a new frontier in the epidemiology of the Trichinella genus. The objective of the present study was to investigate the infectivity of encapsulated species (T. spiralis, T. nativa, T. britovi, T. murrelli and T. nelsoni) and non-encapsulated species (T. pseudospiralis, T. papuae and T. zimbabwensis) in caimans (Caiman crocodilus), varans (Varanus exanthematicus), pythons (Python molurus bivittatus) and turtles (Pelomedusa subrufa) raised at their natural temperature range (26-32 degrees C). Mice and chickens were used as controls. At 6 days post-infection (p.i.), adult worms were detected in the small intestine of reptiles infected with T. papuae and T. zimbabwensis, of chickens infected with T. pseudospiralis and of mice infected with all encapsulated and non-encapsulated species. At 60 days p.i., T. papuae and T. zimbabwensis adult worms were collected from the intestine of varans and caimans and larvae from muscles of the four reptile species, T. pseudospiralis larvae from muscles of chickens, and larvae of all Trichinella species from mouse muscles. The highest reproductive capacity index of both T. papuae and T. zimbabwensis was observed in varans. The results show that T. papuae and T. zimbabwensis are able to complete their entire life-cycle in both poikilothermic and homoiothermic animals.

Animals↗
PubMed2004

International Commission on Trichinellosis: recommendations on the use of serological tests for the detection of Trichinella infection in animals and man.

The use of serological tests to detect Trichinella infection in domestic and wild animals and in humans has not been standardised yet. This review provides an uniform set of recommendations for the development and use of serological tests to detect circulating antibodies in serum samples. The recommendations are based on the best scientific published information and on the unpublished data from laboratories with a great expertise in this field and represent the official position of the International Commission on Trichinellosis regarding acceptable methods and the evaluation of the sensitivity and specificity. These recommendations are subject to change as new scientific information becomes available.

Animals↗
PubMed2004

[Highly Active AntiRetroviral Therapy and opportunistic protozoan infections].

Opportunistic parasite infections (OPIs) are an important cause of morbidity and mortality in persons infected with HIV. In industrialised countries, the use of Highly Active AntiRetroviral Therapy (HAART) results to be effective in suppressing the HIV viral load, with a quantitative and qualitative improvement in the CD4+ T-cell count followed by a strong reduction of opportunistic infections including those caused by parasites. These successes have been mainly attributed to the reconstitution of the cell immunity, which play the most important role in controlling OPIs. However, there are many clinical reports and several laboratory results, which suggest that the control of OPIs in HIV-positive persons under HAART is also induced by the anti-HIV protease inhibitors (PIs), which inhibit the aspartyl proteases of the parasites. The non-conventional use of HIV-PIs seems to be an alternative way for the treatment of parasitic infections, which should be deeply investigated. Of five longitudinal studies carried out before and after the introduction of HAART, four studies showed a strong reduction of toxoplasmic encephalitis (TE) in HIV-positive persons under HAART, whereas in another study, no difference was observed in the incidence rate of TE before and after the introduction of HAART. The influence of HAART in reducing TE has been also confirmed in a randomised, controlled clinical trial, which showed that there is no increase in the risk of developing TE after beginning HAART, even though HIV-infected persons with TE had a discontinuing prophylaxis for Toxoplasma gondii. Four HIV protease inhibitors were tested against the T. gondii virulent RH strain in vitro, alone or in association with pyrimethamine or sulfadiazine. Ritonavir and nelfinavir were highly inhibitory for the parasite growth. Furthermore, none of the antiviral drugs negatively affected the anti-Toxoplasma activity of pyrimethamine or sulfadiazine. In HIV-Leishmania co-infections, a changing pattern has been observed in the HAART era, characterised by a high rate of relapses, which could be explained by the increased survival rate resulting from the effective antiretroviral therapy. A 64.8% decrease of the visceral leishmaniasis incidence was detected after HAART began to be used extensively in Spain. In a large cohort study carried out in ten European countries and in Australia, the relative risk to contract cryptosporidiosis as the first AIDS defining disease was reduced by 96% in the HAART era. In Italy, the relative risk of death for cryptosporidiosis reduced of 74% in the period 1997-98, when HIV-positive persons received HAART. In a large study carried out in Italy, isosporiasis was included in the group of opportunistic infections, of which the relative hazards showed a reduction of 95% in the HAART era. Since 1997, there was the evidence that the use of HAART in persons with advanced HIV infection can improve chronic diarrhoea and lead to disappearance of Enterocytozoon bieneusi from the stools. Although the reconstitution of the cellular immunity seems to be the main factor influencing the reduction of OPIs in persons with AIDS who undergo HAART, there are clinical and microbiological evidences, as well as in vitro and in vivo results, which indicate direct effects of HIV-PIs on the proteases of opportunistic parasites. These findings stress the existence of non-conventional unexpected benefits of PIs in HAART against protozoa. In addition, this benefit of PIs has been demonstrated also for Candida albicans secreted aspartyl proteases and for P. carinii acid proteases. In spite of these important results, HIV PIs are still very toxic for humans, specially in cases of very long treatment, and no clinical trial has been carried out for persons at risk, such as children and pregnant women, because the priority was to reduce the severity of HIV and not the evaluation of possible side effects of the therapy. It follows that further researches are needed to establish the non-conventional use of HIV PIs. Furthermore, the study of PIs against specific aspartyl proteases of those opportunistic protozoa that cause severe and intractable diseases, could be considered an alternative way towards the development of new drugs that may prove effective against these infections.

AIDS-Related Opportunistic Infections↗
PubMed2003

Extraintestinal nematode infections of red foxes (Vulpes vulpes) in Hungary.

A survey was carried out to investigate the prevalence and worm burden of extraintestinal nematodes in 100 red foxes (Vulpes vulpes) of Hungary. The overall prevalence of nematode infections of the respiratory tract was 76%. Eucoleus aerophilus (Capillaria aerophila) was the predominant species (66%), followed by Crenosoma vulpis (24%), Eucoleus (Capillaria) böhmi (8%) and Angiostrongylus vasorum (5%). Pearsonema (Capillaria) plica was found in 52% of the urinary bladders. In 3% of the foxes, Trichinella britovi was present in muscle samples. The high prevalence of lungworms and P. plica and the fox colonisation in urban areas may enhance the prevalence of these nematode infections in domestic dogs and cats, and the flow of T. britovi from the sylvatic cycle to the domestic cycle, enhancing the risk of infections in humans.

Animals↗
PubMed2003

Molecular identification of natural hybrids between Trichinella nativa and Trichinella T6 provides evidence of gene flow and ongoing genetic divergence.

To date, there are no data available on the population genetics of Trichinella due to the lack of genetic markers and the difficulty of working with such small parasites. In the Arctic region of North America and along the Rocky Mountains, there exist two genotypes of Trichinella, Trichinella nativa and Trichinella T6, respectively, which are well differentiated by biochemical and molecular characters. However, both are resistant to freezing, show other common biological characters (e.g. low or no infectivity to rodents and swine) and produce fertile F1 offspring upon interbreeding. To data, these two genotypes have been considered allopatric. In this study, we detected both genotypes in wolves of the same wolf packs in Alaska, suggesting sympatry. A single GTT trinucleotide present in the ITS-2 sequence of T. nativa but not in Trichinella T6 was used as a genetic marker to study gene flow for this character in both a murine infection model and in larvae from naturally-infected Alaskan wolves. Only F1 larvae originating from a cross between T. nativa male and Trichinella T6 female were able to produce F2 offspring. Larvae (F1) originating from a cross between Trichinella T6 male and T. nativa female were not reproductively viable. As expected, all F1 larvae showed a heterozygote pattern for the GTT character upon heteroduplex analysis; however, within the F2 population, the number of observed heterozygotes (n=52) was substantially higher than expected (n=39.08), as supported by the F(is) index, and was not in the Hardy-Weinberg equilibrium. Larvae from two of the 16 Trichinella positive Alaskan wolves, showed the Trichinella T6 pattern or the T. nativa/Trichinella T6 hybrid pattern. Our data demonstrate that T. nativa and Trichinella T6 live in sympatry at least in Alaskan wolves, where T. nativa occurs more frequently (69%) than Trichinella T6 (31%). One explanation for this phenomenon is that glacial periods may have caused a geographical relocation, colonisation and independent evolution of T. nativa within the Rocky Mountains, resulting in a bifurcation of the freeze-resistant genotype. Additional studies will be required to test this hypothesis.

Alaska↗
PubMed2003

Indinavir reduces Cryptosporidium parvum infection in both in vitro and in vivo models.

The use of highly active antiretroviral therapy in persons with acquired immunodeficiency syndrome has reduced the prevalence of infection with Cryptosporidium parvum and the length and severity of its clinical course. This effect has in most cases been attributed to the recovery of the host immunity; however, some works suggest that human immunodeficiency virus protease inhibitors, indinavir in particular, which is one of the human immunodeficiency virus protease inhibitors used in highly active antiretroviral therapy, may be capable of controlling Microsporidia and Cryptosporidium infections, which are refractory to other treatments. The objective of the present study was to investigate the effect of human immunodeficiency virus protease inhibitors on C. parvum infections. Since preliminary experiments using ritonavir, saquinavir, and indinavir showed a drastic reduction of C. parvum infection both in vivo (neonatal Balb/c mice) and in vitro (human ileocecal adenocarcinoma tumour cell line) models, indinavir alone was tested in successive experiments. In vitro, the treatment of the sporulated oocysts with different concentrations of indinavir reduced the percentage of human ileocecal adenocarcinoma tumour cell line infected cells in a dose-dependent manner. For established infection, the treatment with 50 microM of indinavir decreased the percentage of infected cells in a time-dependent manner. In vivo, mice treated with indinavir at the same time they were infected with the oocysts showed a 93% reduction in the number of oocysts present in the entire intestinal contents and a 91% reduction in the number of intracellular parasites in the ileum. For established infection, indinavir treatment reduced the number of oocysts in the entire intestinal content by about 50% and the number of intracellular parasites in the ileum by about 70%. These data show that indinavir directly interferes with the cycle of C. parvum, resulting in a marked reduction in oocyst shedding and in the number of intracellular parasites. Protease inhibitors could be considered as good candidates for the treatment of cyptosporidiosis in immunosuppressed persons.

Animals↗
PubMed2003

Detection and counting of Cryptosporidium parvum in HCT-8 cells by flowcytometry.

The objective of the present study was to evaluate flowcytometry analysis (FCA) as a tool for rapidly and objectively estimating the percentage of cells infected with Cryptosporidium parvum in an in vitro model. We compared the results to those obtained with immunofluorescence assay (IFA) and evaluated the intra-assay variability of both assays and the inter-assay variability of IFA. Human ileocecal adenocarcinoma cells (HCT-8) were infected with different doses of excysted oocysts. After 24 hours, cells were analysed by FCA and by IFA using a monoclonal antibody that recognises a C. parvum antigenic protein and a lectin that binds with glycoproteins present in the parasitophorous vacuoles. The coefficient of variability in terms of the percentage of infected cells was lower for FCA (i.e., 13-14%) than for IFA (i.e., 27-38% when performed by a single operator and 19-22% when performed by three operators), suggesting that FCA is more accurate, in that it is not subject to operator expertise. FCA also has the advantage of allowing the entire culture to be examined, thus avoiding problems with heterogeneity among microscopic fields. In light of these results, this method could also be used to test new anti-Cryptosporidium drugs.

Animals↗
PubMed2002

Trichinella zimbabwensis n.sp. (Nematoda), a new non-encapsulated species from crocodiles (Crocodylus niloticus) in Zimbabwe also infecting mammals.

Since 1995, Trichinella larvae have been detected in 39.5% of farmed crocodiles (Crocodylus niloticus) in Zimbabwe. Morphological, biological, biochemical and molecular studies carried out on one isolate from a farmed crocodile in 2001 support the conclusion that this parasite belongs to a new species, which has been named Trichinella zimbabwensis n.sp. This species, whose larvae are non-encapsulated in host muscles, infects both reptiles and mammals. The morphology of adults and larvae is similar to that of Trichinella papuae. Adults of T. zimbabwensis cross in both directions with adults of T. papuae (i.e. male of T. zimbabwensis per female of T. papuae and male of T. papuae per female of T. zimbabwensis), producing F1 offspring which produce very few and less viable F2 larvae. Muscle larvae of T. zimbabwensis, like those of T. papuae, do not infect birds. Three allozymes (of a total of 10) are diagnostic between T. zimbabwensis and T. papuae, and five are diagnostic between T. zimbabwensis and Trichinella pseudospiralis, the third non-encapsulated species. The percentage of the pairwise alignment identity between T. zimbabwensis and the other Trichinella species for the cytochrome oxidase subunit I gene, the large subunit ribosomal-DNA (mt-lsrDNA) gene and the expansion segment five, shows that T. zimbabwensis is more similar to the two non-encapsulated species T. papuae (91% for cytochrome oxidase I; 96% for mt-lsrDNA; and 88% for expansion segment five) and T. pseudospiralis (88% for cytochrome oxidase I; 90% for mt-lsrDNA; and 66-73% for expansion segment five) than to any of the encapsulated species (85-86% for cytochrome oxidase I; 88-89% for mt-lsrDNA; and 71-79% for expansion segment five). This is the first non-encapsulated species discovered in Africa. The finding of a new Trichinella species that infects both reptiles and mammals suggests that the origin of Trichinella parasites dates back further than previously believed and can contribute to understanding the phylogeny and the epidemiology of the genus Trichinella.

Alligators and Crocodiles↗