[Zika virus infection: what advice in post-epidemic situation?] / Infection par le virus Zika : quels conseils en situation post-épidémique ?

Zika virus infection: what advice in post-epidemic situation? Zika virus transmission is vector-borne, but it can also be sexual. The Zika disease contracted by an adult or child is most often mild but infection of the woman during pregnancy can lead to severe neurological congenital lesions. The Zika virus continues to circulate in many parts of the world. Risk of infection during travel is low but cannot be overlooked. An infected man can be infectious, during sexual intercourse, up to 3 months after contracting the disease. Information of pregnant women and couples with a child project is warranted if at least one of the two trips or has travelled in Zika virus transmission zone. Laboratory serologic tests can be used to determine if the partners have been infected and to verify, through the investigation of the virus in the semen, that there is no risk of sexual transmission.

Infection par le virus zika : quels conseils en situation post-épidémique ? La transmission du virus Zika est vectorielle, mais elle peut aussi être sexuelle. La maladie Zika contractée par un adulte ou un enfant est le plus souvent bénigne, mais l'infection de la femme en cours de grossesse peut aboutir à des lésions congénitales neurologiques graves. Le virus Zika continue de circuler, à bas bruit, dans plusieurs parties du monde. Le risque d'être infecté au cours d'un voyage est faible mais ne peut être négligé. Un homme infecté peut être infectant, lors d'une relation sexuelle, jusqu'à 3 mois après avoir contracté la maladie. L'information des femmes enceintes et des couples ayant un projet d'enfant est justifiée si au moins l'un des deux voyage ou a voyagé en zone de transmission du virus Zika. Il est possible de s'appuyer sur des tests sérologiques de laboratoire pour déterminer si les partenaires ont été infectés et vérifier, par la recherche du virus dans le sperme, qu'il n'y a pas de risque de transmission sexuelle.

Synthetic Antigens Derived from Plasmodium falciparum Sporozoite, Liver, and Blood Stages: Naturally Acquired Immune Response and Human Leukocyte Antigen Associations in Individuals Living in a Brazilian Endemic Area.

Peptide vaccine strategies using Plasmodium-derived antigens have emerged as an attractive approach against malaria. However, relatively few studies have been conducted with malaria-exposed populations from non-African countries. Herein, the seroepidemiological profile against Plasmodium falciparum of naturally exposed individuals from a Brazilian malaria-endemic area against synthetic peptides derived from vaccine candidates circumsporozoite protein (CSP), liver stage antigen-1 (LSA-1), erythrocyte binding antigen-175 (EBA-175), and merozoite surface protein-3 (MSP-3) was investigated. Moreover, human leukocyte antigen (HLA)-DRB1* and HLA-DQB1* were evaluated to characterize genetic modulation of humoral responsiveness to these antigens. The study was performed using blood samples from 187 individuals living in rural malaria-endemic villages situated near Porto Velho, Rondônia State. Specific IgG and IgM antibodies and IgG subclasses were detected by enzyme-linked immunosorbent assay, and HLA-DRB1* and HLA-DQB1* low-resolution typing was performed by PCR-SSP. All four synthetic peptides were broadly recognized by naturally acquired antibodies. Regarding the IgG subclass profile, only CSP induced IgG1 and IgG3 antibodies, which is an important fact given that the acquisition of protective immunity appears to be associated with the cytophilicity of IgG1 and IgG3 antibodies. HLA-DRB1*11 and HLA-DQB1*7 had the lowest odds of responding to EBA-175. Our results showed that CSP, LSA-1, EBA, and MSP-3 are immunogenic in natural conditions of exposure and that anti-EBA antibody responses appear to be modulated by HLA class II antigens.

Vaccination in older adults: development of an educational tool, Vaxisenior, in France.

The benefits of vaccination in older adults are well documented yet there is poor uptake of such preventive measures, and one of the main reasons in France is a lack of recommendation and support from healthcare professionals. To address this issue a multidisciplinary group of experts has developed an educational tool, Vaxisenior, to assist in the training of physicians/healthcare workers who can act as advocates for immunization programs. The tool comprises of eight sections (general introduction; immunosenescence; diphtheria-tetanus-poliomyelitis; influenza; pneumococcus; pertussis; herpes zoster; and vaccines for travelers). In addition, it includes national immunization schedules and recommendations, practical information regarding opportunities to expand vaccine coverage that is convenient to the patient and a questions and answers section covering topics relating to particular usage and responsibilities. Implementation of vaccination policies for older adults is a major issue and will require extensive promotional campaigns, as well as active support from healthcare and public health professionals to improve overall vaccine coverage.

Educational vaccine tools: the French initiative.

Prevention is an important but neglected issue in geriatric medicine. Vaccination plays a major role in prevention of infectious diseases, but its implementation in clinical practice is far from perfect. To improve practice, a group of French experts composed of geriatricians and infectious disease specialists prepared a set of educational material about vaccination for older subjects. The tool has been designed to be used by medical teachers to help them teach this topic to other physicians, nursing staff and students. The group first defined teaching objectives and reviewed the scientific literature on the efficacy and use of various vaccines in the elderly. Results were recorded in 217 slides. These slides were grouped to allow their use for short presentations: the immune system in the elderly and general information about vaccination; universal vaccines, influenza vaccines, pneumococcal vaccines, Herpes zoster vaccine, pertussis vaccine, vaccines for old travellers. Written comments were added to most slides to help presenters teach the topics. The content and design of the slides were analyzed and discussed by the whole group. The set was collected in a CD with ready-to-use files for oral presentations. This educational tool was presented and given to French teachers in geriatrics. It has been used for educational sessions in geriatric hospital wards, for continuous medical education for general practitioners and for courses for physicians learning geriatrics. It has also been proposed to physicians in charge of medical coordination of nursing homes and is available on a web site.

[National plan for the prevention and control "influenza pandemic"]. / Plan national de prévention et de lutte contre une pandémie grippale.

France has developed a national plan for the prevention and control of an influenza pandemic with the aim of reducing its health impact and its consequences on the economic and social life of the country. The main objectives of the plan are to prepare the country to face an epizootic of avian influenza due to a highly pathogenic virus, to detect the first manifestation of a new flu virus, to curb its spread by adopting early and appropriate public health measures and to protect the French population, as well as French citizens abroad. Ensuring that the population has the best possible access to prevention and care, through the organisation and adaptation of the health system facing a pandemic, is one of the major goals of the plan. The plan, and organisation associated to it, forms the foundation of a coherent and adaptable system which every citizen should feel ownership of.

Evaluation of the genetic polymorphism of Plasmodium falciparum P126 protein (SERA or SERP) and its influence on naturally acquired specific antibody responses in malaria-infected individuals living in the Brazilian Amazon.

BACKGROUND: The Plasmodium falciparum P126 protein is an asexual blood-stage malaria vaccine candidate antigen. Antibodies against P126 are able to inhibit parasite growth in vitro, and a major parasite-inhibitory epitope has been recently mapped to its 47 kDa N-terminal extremity (octamer repeat domain--OR domain). The OR domain basically consists of six octamer units, but variation in the sequence and number of repeat units may appear in different alleles. The aim of the present study was to investigate the polymorphism of P126 N-terminal region OR domain in P. falciparum isolates from two Brazilian malaria endemic areas and its impact on anti-OR naturally acquired antibodies. METHODS: The study was carried out in two villages, Candeias do Jamari (Rondonia state) and Peixoto de Azevedo (Mato Grosso state), both located in the south-western part of the Amazon region. The repetitive region of the gene encoding the P126 antigen was PCR amplified and sequenced with the di-deoxy chain termination procedure. The antibody response was evaluated by ELISA with the Nt47 synthetic peptide corresponding to the P126 OR-II domain. RESULTS: Only two types of OR fragments were identified in the studied areas, one of 175 bp (OR-I) and other of 199 bp (OR-II). A predominance of the OR-II fragment was observed in Candeias do Jamari whereas in Peixoto de Azevedo both fragments OR-I and OR-II were frequent as well as mixed infection (both fragments simultaneously) reported here for the first time. Comparing the DNA sequencing of OR-I and OR-II fragments, there was a high conservation among predicted amino acid sequences of the P126 N-terminal extremity. Data of immune response demonstrated that the OR domain is highly immunogenic in natural conditions of exposure and that the polymorphism of the OR domain does not apparently influence the specific immune response. CONCLUSION: These findings confirm a limited genetic polymorphism of the P126 OR domain in P. falciparum isolates and that this limited genetic polymorphism does not seem to influence the development of a specific humoral immune response to P126 and its immunogenicity in the studied population.

Phylogenetic analysis of Trichophyton mentagrophytes human and animal isolates based on MnSOD and ITS sequence comparison.

Dermatophytes are keratinophilic fungi able to infect keratinized tissues of human or animal origin. Among them, Trichophyton mentagrophytes is known to be a species complex composed of several species or variants, which occur in both human and animals. Since the T. mentagrophytes complex includes both anthropophilic and zoophilic pathogens, accurate molecular identification is a critical issue for comprehensive understanding of the clinical and epidemiological implications of the genetic heterogeneity of this complex. Here, 41 T. mentagrophytes isolates from either human patients (14 isolates) or animals (27 isolates) with dermatophytosis were prospectively isolated by culture and identified on morphological bases at the University Hospital Centres of Lille and Poitiers, and the Veterinary School of Alfort, respectively. The isolates were differentiated by DNA sequencing of the variable internal transcribed spacer (ITS) regions flanking the 5.8S rDNA, and of the housekeeping gene encoding the manganese-containing superoxide dismutase (MnSOD), an enzyme which is involved in defence against oxidative stress and has previously provided interesting insight into both fungal taxonomy and phylogeny. ITS1-ITS2 regions and MnSOD sequences successfully differentiate between members of the T. mentagrophytes complex and the related species Trichophyton rubrum. Whatever the phylogenetic marker used, members of this complex were classified into two major clades exhibiting a similar topology, with a higher variability when the ITS marker was used. Relationships between ITS/MnSOD sequences and host origin, clinical pattern and phenotypic characteristics (macroscopic and microscopic morphologies) were analysed.

Prospective evaluation of the new chromogenic medium CandiSelect 4 for differentiation and presumptive identification of the major pathogenic Candida species.

The rapid identification of pathogenic yeasts is a crucial step in ensuring that effective antifungal treatment is started as early as possible. CandiSelect 4 (CS4; Bio-Rad) is a new chromogenic medium for the isolation of fungi, the direct identification of Candida albicans and the presumptive identification of the major pathogenic Candida species. The performance of CS4 was compared with that of another chromogenic medium, CHROMagar Candida (CA; Becton Dickinson). For primary cultures, 502 of the 1549 (32 %) samples were culture-positive. A total of 542 yeasts were isolated including 465 monomicrobial and 37 mixed cultures: 392 C. albicans, 60 Candida glabrata, 25 Candida tropicalis, 12 Candida krusei and 53 other Candida species. The percentage of C. albicans isolates that could be identified directly after 24, 48 and 72 h culture was 31.6, 82.9 and 92.1 %, respectively, for CS4, and 32.9, 82.9 and 91.1 % for CA. The presumptive identification of C. glabrata, C. tropicalis and C. krusei was evaluated after 48 h incubation. The percentage of strains with morphologically typical colonies was 80, 68 and 84.6 %, respectively, for CS4 compared with 75, 76 and 76.9 % for CA. For pure subcultures, from 24 h, all isolates of C. albicans (n=21) were directly identifiable on the two chromogenic media CA and CS4. At 48 h, the proportion of typical strains observed on the two chromogenic media was identical for C. glabrata (85 %) and C. krusei (100 %). A slight difference in favour of CS4 was observed for C. tropicalis (100 vs 95 %). CS4 also allowed the growth of several other fungi. CS4 can be recommended as a primary isolation medium for the identification of C. albicans, and for the rapid and effective differentiation of the major pathogenic Candida species.

Manganese superoxide dismutase based phylogeny of pathogenic fungi.

Superoxide dismutases (SODs), which provide protection against oxidative stress, exhibit an essential role for fungal cell survival, especially during host invasion. Here, 20 partial SOD sequences from 19 pathogenic fungi were determined and aligned with 43 homologous fungal sequences from databases. All sequences encoded tetrameric manganese (Mn)-containing SODs showing predicted cytosolic or mitochondrial subcellular localization. Numerous fungi possessed both cytosolic and mitochondrial MnSODs in addition to the mainly cytosolic copper/zinc isozyme. Moreover, MnSOD sequence variability was higher than SSU rRNA and similar to ITS rRNA, suggesting MnSOD could be used to identify closely related fungal species. MnSOD- and SSU rRNA-based phylogenetic trees were constructed and compared. Despite a more complex topology of the MnSOD tree, due to several gene duplication events, all the classic fungal classes and orders were recovered. A salient point was the existence of two paralogous cytosolic and mitochondrial MnSODs in some Ascomycota. A hypothetical evolutionary scenario with an early gene duplication of the "mitochondrial" gene is proposed.

Candidaemia and antifungal therapy in a French University Hospital: rough trends over a decade and possible links.

BACKGROUND: Evidence for an increased prevalence of candidaemia and for high associated mortality in the 1990s led to a number of different recommendations concerning the management of at risk patients as well as an increase in the availability and prescription of new antifungal agents. The aim of this study was to parallel in our hospital candidemia incidence with the nature of prescribed antifungal drugs between 1993 and 2003. METHODS: During this 10-year period we reviewed all cases of candidemia, and collected all the data about annual consumption of prescribed antifungal drugs. RESULTS: Our centralised clinical mycology laboratory isolates and identifies all yeasts grown from blood cultures obtained from a 3300 bed teaching hospital. Between 1993 and 2003, 430 blood yeast isolates were identified. Examination of the trends in isolation revealed a clear decrease in number of yeast isolates recovered between 1995-2000, whereas the number of positive blood cultures in 2003 rose to 1993 levels. The relative prevalence of Candida albicans and C. glabrata was similar in 1993 and 2003 in contrast to the period 1995-2000 where an increased prevalence of C. glabrata was observed. When these quantitative and qualitative data were compared to the amount and type of antifungal agents prescribed during the same period (annual mean defined daily dose: 2662741; annual mean cost: 615,629 euros) a single correlation was found between the decrease in number of yeast isolates, the increased prevalence of C. glabrata and the high level of prescription of fluconazole at prophylactic doses between 1995-2000. CONCLUSION: Between 1993 and 2000, the number of cases of candidemia halved, with an increase of C. glabrata prevalence. These findings were probably linked to the use of Fluconazole prophylaxis. Although it is not possible to make any recommendations from this data the information is nevertheless interesting and may have considerable implications with the introduction of new antifungal drugs.

Molecular diagnosis of Pneumocystis pneumonia.

The detection of Pneumocystis DNA in clinical specimens by using PCR assays is leading to important advances in Pneumocystis pneumonia (PcP) clinical diagnosis, therapy and epidemiology. Highly sensitive and specific PCR tools improved the clinical diagnosis of PcP allowing an accurate, early diagnosis of Pneumocystis infection, which should lead to a decreased duration from onset of symptoms to treatment, a period with recognized impact on prognosis. This aspect has marked importance in HIV-negative immunocompromised patients, who develop often PcP with lower parasite rates than AIDS patients. The specific amplification of selected polymorphous sequences of Pneumocystis jirovecii genome, especially of internal transcribed spacer regions of the nuclear rRNA operon, has led to the identification of specific parasite genotypes which might be associated with PcP severity. Moreover, multi-locus genotyping revealed to be a useful tool to explore person-to-person transmission. Furthermore, PCR was recently used for detecting P. jirovecii dihydropteroate synthase gene mutations, which are apparently associated with sulfa drug resistance. PCR assays detected Pneumocystis-DNA in bronchoalveolar lavage fluid or biopsy specimens, but also in oropharyngeal washings obtained by rinsing of the mouth. This non-invasive procedure may reach 90%-sensitivity and has been used for monitoring the response to treatment in AIDS patients and for typing Pneumocystis isolates.

Manganese superoxide dismutase in pathogenic fungi: an issue with pathophysiological and phylogenetic involvements.

Manganese-containing superoxide dismutases (MnSODs) are ubiquitous metalloenzymes involved in cell defence against endogenous and exogenous reactive oxygen species. In fungi, using this essential enzyme for phylogenetic analysis of Pneumocystis and Ganoderma genera, and of species selected among Ascomycota, Basidiomycota and Zygomycota, provided interesting results in taxonomy and evolution. The role of mitochondrial and cytosolic MnSODs was explored in some pathogenic Basidiomycota yeasts (Cryptococcus neoformans var. grubii, Cryptococcus neoformans var. gattii, Malassezia sympodialis), Ascomycota filamentous fungi (Aspergillus fumigatus), and Ascomycota yeasts (Candida albicans). MnSOD-based phylogenetic and pathogenic data are confronted in order to evaluate the roles of fungal MnSODs in pathophysiological mechanisms.

Genetic polymorphism of the serine rich antigen N-terminal region in Plasmodium falciparum field isolates from Brazil.

In this work we investigated the frequency of polymorphism in exon II of the gene encoding most of the amino-terminal region of the serine rich antigen (SERA) in Plasmodium falciparum field samples. The blood samples were collected from P. falciparum infected individuals in three areas of the Brazilian Amazon. Two fragments have been characterized by polymerase chain reaction: one of 175 bp corresponding to the repeat region with 5 octamer units and one other of 199 bp related to the 6 repeat octamer units of SERA protein. The 199 bp fragment was the predominant one in all the studied areas. The higher frequency of this fragment has not been described before and could be explained by an immunological selection of the plasmodial population in the infected individuals under study. Since repeat motifs in the amino-terminal region of SERA contain epitopes recognized by parasite-inhibitor antibodies, data reported here suggest that the analysis of the polymorphism of P. falciparum isolates in different geographical areas is a preliminary stage before the final drawing of an universal vaccine against malaria can be reached.

Genetic polymorphism of the serine rich antigen N-terminal region in Plasmodium falciparum field isolates from Brazil

In this work we investigated the frequency of polymorphism in exon II of the gene encoding most of the amino-terminal region of the serine rich antigen (SERA) in Plasmodium falciparum field samples. The blood samples were colleted from P. falciparum infected individuals in three areas of the Brazilian Amazon. Two fragments have been characterized by polymerase chain reaction: one of 175 bp corresponding to the repeat region with 5 octamer units and one other of 199 bp related to the 6 repeat octamer units of SERA protein. The 199 bp fragment was the predominant one in all the studied areas. The higher frequency of this fragment has not been described before and could be explained by an immunological selection of the plasmodial population in the infected individuals under study. Since repeat motifs in the amino-terminal region of SERA contain epitopes recognized by parasite-inhibitor antibodies, data reported here suggest that the analysis of the polymorphism of P. falciparum isolates in different geographical areas is a preliminary stage before the final drawing of an universal vaccine against malaria can be reached.

Use of fluorescence resonance energy transfer hybridization probes to evaluate quantitative real-time PCR for diagnosis of ocular toxoplasmosis.

Toxoplasma gondii infection is an important cause of chorioretinitis in Europe and the United States. Ophthalmological examination and a good clinical response to adequate therapy mainly support ocular toxoplasmosis diagnosis. However, clinical diagnostic may be difficult in some atypical cases. In these cases, laboratory confirmation, based on detection of local specific antibodies and parasite DNA by conventional PCR, is therefore important to confirm the disease etiology. More recently, real-time PCR has been developed to improve prenatal congenital toxoplasmosis diagnosis. We therefore examined the diagnostic value of quantitative real-time PCR for the detection of T. gondii in aqueous humor samples, associated with quantification of human beta-globin to control sample quantitative quality, by using a double fluorescence resonance energy transfer hybridization probes system with a double fluorescence reading. Of the 23 the clinically toxoplasmosis suspect patients, 22 showed serological evidence of exposure to Toxoplasma; one had a serological profile indicative of active infection. The analysis of paired aqueous humor and serum samples revealed an intraocular antibody production in 9 of 23 cases (39.1%). The quantitative real-time PCR revealed positive and high parasite numbers and high Toxoplasma/human genome ratios in three cases. Furthermore, PCR was the only positive confirmatory test in two cases (11.1%). None of the patients included in the control group (n = 7) had evidence of either local specific antibody production or T. gondii DNA detection, suggesting a good relative assay specificity. On the whole, quantitative real-time PCR appears to be useful for diagnosing atypical ocular toxoplasmosis presentations.

Atovaquone-proguanil versus chloroquine-proguanil for malaria prophylaxis in nonimmune pediatric travelers: results of an international, randomized, open-label study.

Atovaquone-proguanil has been shown to be effective and well tolerated for malaria prophylaxis in residents of countries of endemicity and in nonimmune adult travelers, but data about traveling children are limited. In a randomized, open-label, multicenter prophylaxis trial, 221 nonimmune pediatric travelers (age, 2-17 years) received either atovaquone-proguanil or chloroquine-proguanil. Safety and clinical outcome were evaluated 7, 28, and 60 days after travel. By posttravel day 7, a total of 39 (35%) of 110 atovaquone-proguanil and 41 (37%) of 111 chloroquine-proguanil recipients reported > or =1 adverse event. The data indicate that, over the course of treatment, fewer atovaquone-proguanil recipients had treatment-related adverse events (8% vs. 14%), including gastrointestinal complaints (5% vs. 10%). Two subjects discontinued prophylaxis because of drug-related adverse events; both had received chloroquine-proguanil. Observed compliance with prophylaxis was similar before and during travel, but it was higher for atovaquone-proguanil in the posttravel period. No study participant developed malaria. Atovaquone-proguanil was well tolerated and is an important addition to the limited arsenal of prophylactic agents available to children.

Increased sensitivity of mannanemia detection tests by joint detection of alpha- and beta-linked oligomannosides during experimental and human systemic candidiasis.

An enzyme immunoassay (EIA)-the commercially available Platelia Candida antigen test-developed for the diagnosis of systemic candidiasis is based on the detection of alpha-linked oligomannose residues (alpha-Man) released from Candida cells into the serum. This test has good specificity but has to be repeated frequently because of the rapid clearance of detectable mannanemia. We have developed a second EIA based on detection of beta-linked oligomannoses (beta-Man), since beta-Man are linked to different Candida molecules and interact differently with the host immune system and endogenous lectins and should therefore present different kinetics of serum clearance. In a guinea pig model of Candida albicans systemic infection, the relative amounts of detectable alpha- and beta-Man differed considerably according to the virulence of the strain, the infecting dose, and the time after challenge that serum samples were drawn. Detection of alpha-Man was more sensitive per serum sample than that of beta-Man, and the sensitivity for the combination reached 90%. The same tests were applied to 90 sera from 26 patients selected retrospectively for having been infected with the most-pathogenic Candida species: C. albicans (19), C. tropicalis (4), and C. glabrata (3). A total of 22 patients had positive antigenemia, 4 had alpha-mannanemia, 4 had beta-mannanemia, and 14 showed the presence of both. For the patients showing the presence of both forms of mannanemia, the use of both tests enhanced the duration of the detection of mannanemia. Mannanemia was correlated with early clinical symptoms and isolation of Candida in culture, which occurred in 55% of the patients at an average of 4.7 days after the first positive mannanemia test result. A combination of the two tests had a cumulated specificity of 95%, and positive and negative predictive values were 79 and 97%, respectively. These findings provide evidence for different kinetics of beta- and alpha-Man circulation during experimental and human candidiasis and suggest the joint detection of both types of epitopes as a rational approach contributing to increases in the sensitivity and earliness of diagnosis.

Successful outcome of disseminated Fusarium infection with skin localization treated with voriconazole and amphotericin B-lipid complex in a patient with acute leukemia.

A disseminated Fusarium oxysporum infection with skin localization was diagnosed in a woman with a relapse of B-acute leukemia during induction chemotherapy. The infection was refractory to amphotericin B-lipid complex alone but responded successfully when voriconazole was added.