Epidemiological determinants and PCR results in Central African inhabitants with a new and frequent HTLV indeterminate Western Blot pattern exhibiting mostly p28, p32, p36, and a shifted GD21

International audiencen.

Polymerase chain reaction in the diagnosis and prognosis of Mediterranean visceral leishmaniasis in immunocompetent children

OBJECTIVE: To assess the usefulness of a polymerase chain reaction (PCR) assay amplifying the small subunit rRNA coding region of Leishmania species performed on peripheral blood (PB) and bone marrow (BM) aspirates for the diagnosis and follow-up of visceral leishmaniasis (VL) in children living in the Mediterranean basin. DESIGN: A prospective study was conducted on children consecutively hospitalized over a 1-year period at our Infectious Diseases Department in Sicily (Italy) presenting with fever, hepatosplenomegaly, and/or pancytopenia and a positive Leishmania serology (> or =1:40). RESULTS: Among the 14 patients hospitalized with signs and symptoms suggestive of the disease and a positive serology, we identified 10 cases of Mediterranean VL. PCR performed on PB and BM aspirates was positive in all cases and concordant with microscopy and/or culture performed on BM. Leishmania DNA was cleared from PB a median of 6 days after the start of treatment; during follow-up (median: 9 months; range: 6-12 months) 1 child relapsed. In this case, BM PCR remained positive with rapid reappearance of a positive signal also in PB. CONCLUSIONS: PB PCR allows a rapid and noninvasive parasitologic diagnosis of Mediterranean VL among immunocompetent children and is at least as sensitive as a diagnosis made on the basis of BM aspirates. The lack of disappearance from BM and the reappearance of positive PCR on PB is predictive of clinical relapse. Qualitative and semiquantitative PCR may be the standard method for monitoring response to therapy in immunocompetent childre

Clinical use of polymerase chain reaction performed on peripheral blood and bone marrow samples for the diagnosis and monitoring of visceral leishmaniasis in HIV-infected and HIV-uninfected patients: a single-center, 8-year experience in Italy and review of the literature

Background. To overcome some of the limitations of conventional microbiologic techniques, polymerase chain reaction (PCR)–based assays are proposed as useful tools for the diagnosis of visceral leishmaniasis. Patients and methods. A comparative study using conventional microbiologic techniques (i.e., serologic testing, microscopic examination, and culture) and a Leishmania species–specific PCR assay, using peripheral blood and bone marrow aspirate samples as templates, was conducted during an 8-year period. The study cohort consisted of 594 Italian immunocompetent (adult and pediatric) and immunocompromised (adult) patients experiencing febrile syndromes associated with hematologic alterations and/or hepatosplenomegaly. Identification of the infecting protozoa at the species level was directly obtained by PCR of peripheral blood samples, followed by restriction fragment–length polymorphism analysis of the amplified products, and the results were compared with those of isoenzyme typing of Leishmania species strains from patients, which were isolated in vitro. Results. Sixty-eight patients (11.4%) had a confirmed diagnosis of visceral leishmaniasis. Eleven cases were observed in human immunodeficiency virus (HIV)–uninfected adults, 20 cases were observed in HIV-infected adults, and the remaining 37 cases were diagnosed in HIV-uninfected children. In the diagnosis of primary visceral leishmaniasis, the sensitivities of the Leishmania species–specific PCR were 95.7% for bone marrow aspirate samples and 98.5% for peripheral blood samples versus sensitivities of 76.2%, 85.5%, and 90.2% for bone marrow aspirate isolation, serologic testing, and microscopic examination of bone marrow biopsy specimens, respectively. None of 229 healthy blood donors or 25 patients with imported malaria who were used as negative control subjects had PCR results positive for Leishmania species in peripheral blood samples (i.e., specificity of Leishmania species– specific PCR, 100%). PCR and restriction fragment–length polymorphism analysis for Leishmania species identification revealed 100% concordance with isoenzyme typing in the 19 patients for whom the latter data were available. Conclusions. PCR assay is a highly sensitive and specific tool for the diagnosis of visceral leishmaniasis in both immunocompetent and immunocompromised patients and can be reliably used for rapid parasite identification at the species level

Frequent and Recent Human Acquisition of Simian Foamy Viruses Through Apes' Bites in Central Africa

Human infection by simian foamy viruses (SFV) can be acquired by persons occupationally exposed to non-human primates (NHP) or in natural settings. This study aimed at getting better knowledge on SFV transmission dynamics, risk factors for such a zoonotic infection and, searching for intra-familial dissemination and the level of peripheral blood (pro)viral loads in infected individuals. We studied 1,321 people from the general adult population (mean age 49 yrs, 640 women and 681 men) and 198 individuals, mostly men, all of whom had encountered a NHP with a resulting bite or scratch. All of these, either Pygmies (436) or Bantus (1085) live in villages in South Cameroon. A specific SFV Western blot was used and two nested PCRs (polymerase, and LTR) were done on all the positive/borderline samples by serology. In the general population, 2/1,321 (0.2%) persons were found to be infected. In the second group, 37/198 (18.6%) persons were SFV positive. They were mostly infected by apes (37/39) FV (mainly gorilla). Infection by monkey FV was less frequent (2/39). The viral origin of the amplified sequences matched with the history reported by the hunters, most of which (83%) are aged 20 to 40 years and acquired the infection during the last twenty years. The (pro)viral load in 33 individuals infected by a gorilla FV was quite low (<1 to 145 copies per 105 cells) in the peripheral blood leucocytes. Of the 30 wives and 12 children from families of FV infected persons, only one woman was seropositive in WB without subsequent viral DNA amplification. We demonstrate a high level of recent transmission of SFVs to humans in natural settings specifically following severe gorilla bites during hunting activities. The virus was found to persist over several years, with low SFV loads in infected persons. Secondary transmission remains an open question

Trends in the prevalence and distribution of HTLV-1 and HTLV-2 infections in Spain

<p>Abstract</p> <p>Background</p> <p>Although most HTLV infections in Spain have been found in native intravenous drug users carrying HTLV-2, the large immigration flows from Latin America and Sub-Saharan Africa in recent years may have changed the prevalence and distribution of HTLV-1 and HTLV-2 infections, and hypothetically open the opportunity for introducing HTLV-3 or HTLV-4 in Spain. To assess the current seroprevalence of HTLV infection in Spain a national multicenter, cross-sectional, study was conducted in June 2009.</p> <p>Results</p> <p>A total of 6,460 consecutive outpatients attending 16 hospitals were examined. Overall, 12% were immigrants, and their main origin was Latin America (4.9%), Africa (3.6%) and other European countries (2.8%). Nine individuals were seroreactive for HTLV antibodies (overall prevalence, 0.14%). Evidence of HTLV-1 infection was confirmed by Western blot in 4 subjects (prevalence 0.06%) while HTLV-2 infection was found in 5 (prevalence 0.08%). Infection with HTLV types 1, 2, 3 and 4 was discarded by Western blot and specific PCR assays in another two specimens initially reactive in the enzyme immunoassay. All but one HTLV-1 cases were Latin-Americans while all persons with HTLV-2 infection were native Spaniards.</p> <p>Conclusions</p> <p>The overall prevalence of HTLV infections in Spain remains low, with no evidence of HTLV-3 or HTLV-4 infections so far.</p

Exploring mobility in Italian Neolithic and Copper Age communities

As a means for investigating human mobility during late the Neolithic to the Copper Age in central and southern Italy, this study presents a novel dataset of enamel oxygen and carbon isotope values (delta (18)Oca and delta (13)Cca) from the carbonate fraction of biogenic apatite for one hundred and twenty-six individual teeth coming from two Neolithic and eight Copper Age communities. The measured delta (18)Oca values suggest a significant role of local sources in the water inputs to the body water, whereas delta (13)Cca values indicate food resources, principally based on C-3 plants. Both delta (13)Cca and delta (18)Oca ranges vary substantially when samples are broken down into local populations. Statistically defined thresholds, accounting for intra-site variability, allow the identification of only a few outliers in the eight Copper Age communities, suggesting that sedentary lifestyle rather than extensive mobility characterized the investigated populations. This seems to be also typical of the two studied Neolithic communities. Overall, this research shows that the investigated periods in peninsular Italy differed in mobility pattern from the following Bronze Age communities from more northern areas

Ancient, independent evolution and distinct molecular features of the novel human T-lymphotropic virus type 4

<p>Abstract</p> <p>Background</p> <p>Human T-lymphotropic virus type 4 (HTLV-4) is a new deltaretrovirus recently identified in a primate hunter in Cameroon. Limited sequence analysis previously showed that HTLV-4 may be distinct from HTLV-1, HTLV-2, and HTLV-3, and their simian counterparts, STLV-1, STLV-2, and STLV-3, respectively. Analysis of full-length genomes can provide basic information on the evolutionary history and replication and pathogenic potential of new viruses.</p> <p>Results</p> <p>We report here the first complete HTLV-4 sequence obtained by PCR-based genome walking using uncultured peripheral blood lymphocyte DNA from an HTLV-4-infected person. The HTLV-4(1863LE) genome is 8791-bp long and is equidistant from HTLV-1, HTLV-2, and HTLV-3 sharing only 62–71% nucleotide identity. HTLV-4 has a prototypic genomic structure with all enzymatic, regulatory, and structural proteins preserved. Like STLV-2, STLV-3, and HTLV-3, HTLV-4 is missing a third 21-bp transcription element found in the long terminal repeats of HTLV-1 and HTLV-2 but instead contains unique c-Myb and pre B-cell leukemic transcription factor binding sites. Like HTLV-2, the PDZ motif important for cellular signal transduction and transformation in HTLV-1 and HTLV-3 is missing in the C-terminus of the HTLV-4 Tax protein. A basic leucine zipper (b-ZIP) region located in the antisense strand of HTLV-1 and believed to play a role in viral replication and oncogenesis, was also found in the complementary strand of HTLV-4. Detailed phylogenetic analysis shows that HTLV-4 is clearly a monophyletic viral group. Dating using a relaxed molecular clock inferred that the most recent common ancestor of HTLV-4 and HTLV-2/STLV-2 occurred 49,800 to 378,000 years ago making this the oldest known PTLV lineage. Interestingly, this period coincides with the emergence of <it>Homo sapiens sapiens </it>during the Middle Pleistocene suggesting that early humans may have been susceptible hosts for the ancestral HTLV-4.</p> <p>Conclusion</p> <p>The inferred ancient origin of HTLV-4 coinciding with the appearance of <it>Homo sapiens</it>, the propensity of STLVs to cross-species into humans, the fact that HTLV-1 and -2 spread globally following migrations of ancient populations, all suggest that HTLV-4 may be prevalent. Expanded surveillance and clinical studies are needed to better define the epidemiology and public health importance of HTLV-4 infection.</p

Molecular Ecology and Natural History of Simian Foamy Virus Infection in Wild-Living Chimpanzees

Identifying microbial pathogens with zoonotic potential in wild-living primates can be important to human health, as evidenced by human immunodeficiency viruses types 1 and 2 (HIV-1 and HIV-2) and Ebola virus. Simian foamy viruses (SFVs) are ancient retroviruses that infect Old and New World monkeys and apes. Although not known to cause disease, these viruses are of public health interest because they have the potential to infect humans and thus provide a more general indication of zoonotic exposure risks. Surprisingly, no information exists concerning the prevalence, geographic distribution, and genetic diversity of SFVs in wild-living monkeys and apes. Here, we report the first comprehensive survey of SFVcpz infection in free-ranging chimpanzees (Pan troglodytes) using newly developed, fecal-based assays. Chimpanzee fecal samples (n = 724) were collected at 25 field sites throughout equatorial Africa and tested for SFVcpz-specific antibodies (n = 706) or viral nucleic acids (n = 392). SFVcpz infection was documented at all field sites, with prevalence rates ranging from 44% to 100%. In two habituated communities, adult chimpanzees had significantly higher SFVcpz infection rates than infants and juveniles, indicating predominantly horizontal rather than vertical transmission routes. Some chimpanzees were co-infected with simian immunodeficiency virus (SIVcpz); however, there was no evidence that SFVcpz and SIVcpz were epidemiologically linked. SFVcpz nucleic acids were recovered from 177 fecal samples, all of which contained SFVcpz RNA and not DNA. Phylogenetic analysis of partial gag (616 bp), pol-RT (717 bp), and pol-IN (425 bp) sequences identified a diverse group of viruses, which could be subdivided into four distinct SFVcpz lineages according to their chimpanzee subspecies of origin. Within these lineages, there was evidence of frequent superinfection and viral recombination. One chimpanzee was infected by a foamy virus from a Cercopithecus monkey species, indicating cross-species transmission of SFVs in the wild. These data indicate that SFVcpz (i) is widely distributed among all chimpanzee subspecies; (ii) is shed in fecal samples as viral RNA; (iii) is transmitted predominantly by horizontal routes; (iv) is prone to superinfection and recombination; (v) has co-evolved with its natural host; and (vi) represents a sensitive marker of population structure that may be useful for chimpanzee taxonomy and conservation strategies

Chimpanzee Malaria Parasites Related to Plasmodium ovale in Africa

Since the 1970's, the diversity of Plasmodium parasites in African great apes has been neglected. Surprisingly, P. reichenowi, a chimpanzee parasite, is the only such parasite to have been molecularly characterized. This parasite is closely phylogenetically related to P. falciparum, the principal cause of the greatest malaria burden in humans. Studies of malaria parasites from anthropoid primates may provide relevant phylogenetic information, improving our understanding of the origin and evolutionary history of human malaria species. In this study, we screened 130 DNA samples from chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) from Cameroon for Plasmodium infection, using cytochrome b molecular tools. Two chimpanzees from the subspecies Pan t. troglodytes presented single infections with Plasmodium strains molecularly related to the human malaria parasite P. ovale. These chimpanzee parasites and 13 human strains of P. ovale originated from a various sites in Africa and Asia were characterized using cytochrome b and cytochrome c oxidase 1 mitochondrial partial genes and nuclear ldh partial gene. Consistent with previous findings, two genetically distinct types of P. ovale, classical and variant, were observed in the human population from a variety of geographical locations. One chimpanzee Plasmodium strain was genetically identical, on all three markers tested, to variant P. ovale type. The other chimpanzee Plasmodium strain was different from P. ovale strains isolated from humans. This study provides the first evidence of possibility of natural cross-species exchange of P. ovale between humans and chimpanzees of the subspecies Pan t. troglodytes