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H Zeller

Publications and source records attributed to H Zeller.

At least 19 recordsLinked to original sources
PubMed2006

Remote sensing based identification of environmental risk factors associated with West Nile disease in horses in Camargue, France.

Geographic information system and remote sensing technologies were used to identify landscape features associated with risk of West Nile virus transmission as defined by the presence of confirmed horse cases. SPOT-4 images of Camargue area were used to generate a map of landscape categories of epidemic foci and the geographic information system was employed to determine the proportion of landscape components surrounding 10 horse case sites and 17 control sites. The spatio-temporal analysis of the cases outbreak gave the best results for a spatial window of 9 km and a temporal window of 18 days. Two clusters were identified (relative risk=3.35), both in the wet area of Camargue, near the town "Les Saintes Maries de la Mer". The first one was 4 km radius, the second 9 km. The relationships between the presence of cases and proportions of landscape categories were analyzed using generalized linear model. The best model indicated that rice fields and dry bushes, wet "sansouire" and open water were the major components of the landscape that were associated with the presence of West Nile virus cases.

Animals↗
PubMed2005

[Increase of Hantavirus infections in France, 2003].

BACKGROUND: Hantaviral infections causing hemorrhagic fever with renal syndrome are endemic in North Eastern France. Humans are contaminated by the inhalation of aerosols contaminated by rodent faeces. In February 2003, the National reference centre (NRC) for hemorrhagic fevers detected an increased number of cases. An investigation was carried out to confirm the outbreak and take appropriate control measures. METHODS: Cases were collected by the NRC. A case was defined as a person living in France with symptoms compatible with hantaviral infection and a positive blood test both for specific Puumala IgM, and IgG. Clinical information and at-risk exposures during the 2 weeks before onset were recorded. RESULTS: In 2003, 128 cases were diagnosed (61 in 2002). The median age of patients was 38, 77% were men and 82% were hospitalized. Patients were living in North-Eastern France. Clusters were detected in the Ardennes and Oise districts. Occupation (35%) (in agriculture, forestry, and construction work), manipulation of firewood (35%), gardening (29%), and outdoors leisure (14%) were identified as at-risk exposures in these cases. CONCLUSIONS: An increased number of positive diagnoses of hantaviral infections was confirmed. The location and at-risk exposures of the cases were identical in previous investigations. Exclusion and prevention of rodents' access to houses and avoiding the inhalation of contaminated dust are the only possible prevention measures of hantaviral infections. Information about the disease and its prevention needs to be made widely available to both healthcare professionals and the general population living in endemic areas.

Adolescent↗
PubMed2005

Skin manifestations of West Nile virus infection.

West Nile virus (WNV) infection is a potentially lethal arbovirus infection. Many notable outbreaks have occurred during the last few years throughout the world, including Europe and the USA. The severity of the disease is mainly related to the neurological complications. A maculopapular exanthema is reported as a clinical sign of the disease. Recently an outbreak of WNV infection occurred in southern France. Three patients out of 6 had a similar skin roseola-like eruption. The cluster of 3 cases of similar febrile roseola of unexplained cause during the same week led to the diagnosis of the first WNV human outbreak in France for 40 years.

Adult↗
PubMed2003

Evolutionary relationship between Old World West Nile virus strains. Evidence for viral gene flow between Africa, the Middle East, and Europe.

Little is known about the genetic relationships between European and other Old-World strains of West Nile virus (WNV) and persistence of WNV North of Mediterranean. We characterized the complete genomes of three WNV strains from France (horse-2000), Tunisia (human-1997) and Kenya (mosquito-1998), and the envelope, NS3 and NS5 genes of the Koutango virus. Phylogenetic analyses including all available full-length sequences showed that: (1) Koutango virus is a distant variant of WNV; (2) the three characterized strains belong to lineage 1, clade 1a; (3) the Tunisian strain roots the lineage of viruses introduced in North America. We established that currently available partial envelope sequences do not generate reliable phylogenies. Accordingly, establishing a large WNV sequence database is pivotal for the understanding of spatial and temporal epidemiology of this virus. For rapid completion of that purpose, colinearized E-NS3-NS5 gene sequences were shown to constitute a valuable surrogate for complete sequences.

Africa↗
PubMed2003

Expression of the nucleoprotein of the Puumala virus from the recombinant Semliki Forest virus replicon: characterization and use as a potential diagnostic tool.

Puumala virus (Bunyaviridae family, Hantavirus genus) causes a mild form of hemorrhagic fever with renal syndrome (HFRS) called nephropathia epidemica in northern and central Europe. Serological tests are used for diagnosis, but antigen production is difficult because the virus grows poorly in tissue culture. We expressed the N protein (nucleoprotein) of Puumala virus via the Semliki Forest virus (SFV) replicon in mammalian cells and compared its antigenic properties with those of the native antigen derived from Puumala virus-infected cells. Detection of immunoglobulin G or immunoglobulin M by enzyme-linked immunosorbent assay (ELISA), micro -capture ELISA, and indirect immunofluorescence assay was (at least) as effective with the recombinant antigen as with the native antigen when HFRS patient sera or organ washes from wild rodents were tested. No nonspecific reaction was observed. Thus, the SFV-expressed N protein of Puumala virus appears as a valid antigen, specific and sensitive for serological investigations.

Animals↗
PubMed2002

[Rift Valley fever: sporadic infection of French military personnel outside currently recognized epidemic zones].

For three years the arbovirus surveillance unit of the Tropical Medicine Institute of the French Army Medical Corps (French acronym IMTSSA) in Marseille, France has been investigating causes of benign non-malarial febrile syndromes in French military personnel serving outside mainland France. The methodology used in N'Djamena consisted of sending frozen specimens collected concomitant with viremia, to Marseille for culture. During the rainy season of 2001, specimens were collected from a total of 50 febrile soldiers. Cultures allowed isolation and identification of two strains of Rift Valley virus. The risk of contamination exists not only in the field but also in mainland hospital departments treating infected patients. Routine serological diagnosis for Rift Valley fever must be DISCUSSED for all patients in the field or returning from Africa.

Adult↗
PubMed2002

[Ebola: a virus endemic to central Africa?].

From October 2001 to March 2002, an outbreak of Ebola haemorrhagic fever occurred in the North-Eastern Gabon (63 cases) and neighbouring Congo (57 cases). It was the fourth epidemic in North Eastern Gabon since 1994. Meanwhile this outbreak differed from the previous epidemics: at least five different emerging sources of the virus in the human population were observed from the local fauna resulting in fears of an endemic Ebola virus in the area. The control of the outbreak was uneasy because of the unfriendly attitude of the local population related to the restrictive measures for the isolation of suspected patients and the epidemiological surveillance. Such rejection process emphasizes the need of a continuous increasing public awareness.

Animals↗
PubMed2001

Mass vaccination campaigns to eradicate poliomyelitis in Madagascar: oral poliovirus vaccine increased immunity of children who missed routine programme.

To assess the impact of mass vaccination campaigns using oral poliovirus vaccine (OPV) in Madagascar, serum neutralizing antibodies and geometrical mean titres (GMTs) to poliovirus were measured among 472 children aged up to 59 months, before and after the mass campaign, regardless of their previous history of routine vaccination. In this study, overall coverage with three routine and two mass campaign OPV doses was 69.9 and 93.4%, respectively. Seroprevalences to all poliovirus types were significantly higher after the mass campaign among the children who were not vaccinated through routine programme: 67.5% vs. 90.2% (P < 0.001) for type 1; 66.7% vs. 95.1% (P < 0.001) for type 2; and 55.3% vs. 82.9% (P < 0.001) for type 3. Geometrical mean titres to all poliovirus types also significantly increased after the mass campaign among the same study group: 34.5 vs. 238.9 (P < 0.001) for type 1; 35.1 vs. 402.6 (P < 0.001) for type 2; and 13.3 vs. 92.6 (P < 0.001) for type 3. Post-mass campaign seroprevalences and GMTs for poliovirus, especially types 1 and 3, among children who received up to two routine and two mass campaign OPV doses were significantly higher than pre-mass campaign seroprevalences among children who received three routine OPV doses. Reasons for lack of adherence to the vaccination programme and the mass campaign are discussed. The findings strongly support the WHO strategy of conducting mass campaign in all endemic countries. However, as the mass campaign strategy now has been discontinued, it is crucial to increase the routine coverage and to improve acute flaccid paralysis surveillance in order to fulfil the goal of poliomyelitis eradication.

Antibodies, Viral↗
PubMed2001

[African Swine Fever introduction into Madagascar, history and lessons from an emergence].

African Swine Fever (ASF) was diagnosed for the first time in Madagascar in 1998. ASF has apparently been introduced from the African continent to the southern part of the island with a subsequent spread to other regions except for areas in the north and in the west. The epidemic has had severe economic consequences for the home market of pork meat production. This article reviews the course of the epidemic with particular emphasis on the vectors involved in the transmission of the virus, such as the soft tick, Ornithodoros moubata porcinus. Presence of this vector and of the bushpig, Potamochoerus larvatus, as a potential wild reservoir, are some of the major obstacles in control of ASF in Madagascar. A veterinary disease surveillance system has to be urgently warranted.

African Swine Fever↗
PubMed2000

Hirudin reduces tissue factor expression and attenuates graft arteriosclerosis in rat cardiac allografts.

BACKGROUND-Intravascular clotting has been implicated in the pathogenesis of cardiac allograft vasculopathy (CAV). We previously identified the expression of tissue factor (TF), the primary cellular initiator of blood coagulation, within the coronary intima, which was associated with neointimal thickening. In the present study, the effect of recombinant hirudin on CAV was assessed in Lewis to Fisher rat heterotopic cardiac allografts. METHODS AND RESULTS-Transplant recipients were randomized to a control group (n=10) and a hirudin-treated group (n=12; 2 mg. kg(-1). d(-1) SC). Histological evaluations of rejection, CAV, and TF staining were performed 120 days after transplantation. No significant differences were observed between the 2 groups with respect to the degree of rejection. Hirudin significantly (P<0.05) suppressed the development of CAV in the graft microvessels, but it was less effective in large coronary arteries. Graft intimal cells, isolated by laser-assisted cell picking, showed a marked upregulation of TF gene transcription, which was prevented by hirudin (P<0.01). As demonstrated by immunohistochemistry and quantitative analyses of TF mRNA levels by real-time polymerase chain reaction, hirudin treatment resulted in a significant reduction of TF protein and mRNA expression (P<0.001). CONCLUSIONS-Treatment with hirudin in this rat cardiac transplant model inhibited TF expression and decreased neointimal hyperplasia. These results suggest that TF inhibition by hirudin, in addition to its direct effect on thrombin, may attenuate the hypercoagulable state and prevent the development of CAV at least in restricted sites of the graft coronary vasculature.

Animals↗
PubMed2000

Infections by viruses of the families Bunyaviridae and Filoviridae.

Rift Valley fever is the most important bunyaviral disease of animals in Africa. The virus, transmitted by mosquitoes, causes abortions and mortality in young animals in addition to haemorrhagic fevers in humans. Although vaccines against this virus are available, the uses of these vaccines are limited because of deleterious effects or incomplete protection, justifying further studies to improve the existing vaccines or to develop others. Nairobi sheep disease is transmitted by ticks. The disease is endemic in East Africa and sporadic cases are reported in India and Sri Lanka. Other viruses transmitted by mosquitoes or midges are teratogenic in cattle or sheep, these include Akabane and related viruses in Asia, Australia and the Middle East, and Cache Valley in North America. The Marburg and Ebola viruses of the genus Filovirus are associated with epidemics in Central Africa with high fatality rates in humans; some outbreaks were related to contact with monkeys. Another subtype of Ebola virus was first described in a quarantine facility in the United States of America among cynomolgus monkeys (Macaca fascicularis) from the Philippines. The reservoir of these viruses remains unknown.

Animals↗
PubMed2000

[Hantavirus: recent data and review of the literature].

Hantavirus (Bunyaviridae family) are present worldwide and are the causative agent of haemorrhagic fever with renal or pulmonary syndrome. These viruses are transmitted by rodents with asymptomatic infection which thus act as an excellent reservoir. Molecular epidemiology indicates that Hantavirus may have evolved in three ways: mutations within the genome, reassortment of the segmented genome between two closely related Hantavirus, and genomic recombination, a relatively rare phenomenon among negative stranded RNA viruses. Each virus is carried primarily by a specific rodent host. This observation is confirmed by phylogenetic analyses: the evolution tree of the different Hantavirus, based on viral genomic sequences has been shown to mirror the evolution tree of their specific rodents, based on sequences of mitochondrial DNA. Altogether these data suggest that an ancestral Hantavirus infected a specific rodent, early during evolution, and was subsequently submitted to the same evolutionary pressure as the rodent host.

Animals↗
PubMed2000

[Circulation of the poliovirus in endemic zones with children vaccinated by the oral polio vaccine].

Strategies aiming to eradicate the poliovirus and poliomyelitis seek primarily to eliminate wild strains associated with the disease, by means of world wide vaccination campaigns using the oral attenuated vaccine (OPV). OPV contains attenuated viral strains which retain their replicating capacity in the digestive tract and thus induce the development of an antiviral local intestinal immunity and limit the circulation of the virus. In such a context, poliomyelitis surveillance laboratories should study above all cases of acute flaccid paralysis (AFP), highlighting the circulation of wild strains, identifying regional reservoirs and guiding vaccination strategies. Alongside circulation, there appear to be important genetic and phenotypic shifts in vaccinating strains, since the OPV is capable of preserving a reservoir of pathogenic stains and thereby impairing vaccination efficacy and the eradication of the virus. Furthermore, non-polio enteroviruses should be considered as a source of emerging pathogenic strains. These questions are being studied by the Pasteur Institute with the objective of determining the effects of OPV campaigns on the circulation of the poliovirus. We have studied the poliovirus vaccine and the circulation of wild strains in urban and peripheral urban areas in African countries known to be endemic for poliomyelitis (Central African Republic, Madagascar, Côte d'Ivoire). The study population consisted of children who had already been vaccinated and new-borns in the course of vaccination. We also evaluated the diffusion of the vaccine strains in their immediate environment. Genetic interchanges were taken into account. For children who received the 3-4 OPV doses, asymptomatic virus excretion was insignificant (0.4-2.4%). The rate of virus excretion in the surrounding environment of children in the course of being vaccinated was relatively low (1.76-5.3%). Our study also detected variant and recombinant strains.

Central African Republic↗