Search

Parasites and microorganisms (protozoa, bacteria, and viruses) are still a concern despite progress in hygiene and anti-infectious therapy. To control viral infections, with AIDS and viral hepatitis B and C disregarded, only a limited number of antivirals are available for either chronic (e.g., herpes virus infections) or acute (e.g., influenza) infections, and in the case of acute episodes, they have to be administered as soon as possible or given for prevention. The administration of the tetravalent dengue vaccine, Dengvaxia SP ® sp (four chimeric vaccinal recombinant strains of I yellow fever virus i each expressing antigens of one of the four types of Dengue virus), is strictly limited to children aged from 9 to 16 years with laboratory-confirmed previous dengue virus infection and living in an endemic area [[10]]. The introduction of new pathogens or the spread of previously seldom described infections (e.g., viral zoonosis, Table 1) occurs continuously and some examples are briefly described below: - I Candida auris i : This emerging yeast, responsible for life-threatening infections, is in most cases resistant to anti-fungal treatment. [Extracted from the article]

Since its outbreak, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spread rapidly, causing the Coronavirus Disease 19 (COVID-19) pandemic. Even with the vaccines' administration, the virus continued to circulate due to inequal access to prevention and therapeutic measures in African countries. Information about COVID-19 in Africa has been limited and contradictory, and thus regional studies are important. On this premise, we conducted a genomic surveillance study about COVID-19 lineages circulating in Bangui, Central African Republic (CAR). We collected 2687 nasopharyngeal samples at four checkpoints in Bangui from 2 to 22 July 2021. Fifty-three samples tested positive for SARS-CoV-2, and viral genomes were sequenced to look for the presence of different viral strains. We performed phylogenetic analysis and described the lineage landscape of SARS-CoV-2 circulating in the CAR along 15 months of pandemics and in Africa during the study period, finding the Delta variant as the predominant Variant of Concern (VoC). The deduced aminoacidic sequences of structural and non-structural genes were determined and compared to reference and reported isolates from Africa. Despite the limited number of positive samples obtained, this study provides valuable information about COVID-19 evolution at the regional level and allows for a better understanding of SARS-CoV-2 circulation in the CAR. [ABSTRACT FROM AUTHOR]

National malaria management policy is based upon the availability of effective and affordable antimalarial drugs. This study was undertaken to evaluate the quality of the treatment of uncomplicated malaria cases in Bangui, an area with multidrug-resistant parasites, at a time preceding implementation of a new therapeutic policy relying on the artemisinin derivative combined treatment artemether-lumefantrine. A cross-sectional study was carried out in Bangui city to assess availability of antimalarial drugs and the performances of health workers in the management of uncomplicated malaria. Availability of drugs was recorded in all drugs wholesalers (n = 3), all pharmacies in health facilities (n = 14), private drugstores (n = 15), and in 60 non-official drug shops randomly chosen in the city. Despite a limited efficacy at the time of the survey, chloroquine remained widely available in the official and nonofficial markets. Artemisinin derivatives used in monotherapy or in combination were commonly sold. In health care facilities, 93% of the uncomplicated malaria cases were treated in the absence of any laboratory confirmation and the officially recommended treatment, amodiaquine-sulfadoxine/pyrimethamine, was seldom prescribed. Thus, the national guidelines for the treatment of uncomplicated malaria are not followed by health professionals in Bangui. Its use should be implemented while a control of importation of drug has to be reinforced. [ABSTRACT FROM AUTHOR]

National malaria management policy is based upon the availability of effective and affordable antimalarial drugs. This study was undertaken to evaluate the quality of the treatment of uncomplicated malaria cases in Bangui, an area with multi-drug resistant parasites, at a time preceding implementation of a new therapeutic policy relying on the artemisinin derivative combined treatment artemether-lumefantrine . A cross-sectional study was carried out in Bangui city to assess availability of antimalarial drugs and the performances of health workers in the management of uncomplicated malaria. Availability of drugs was recorded in all drugs wholesalers (n=3), all Pharmacies in health facilities (n=14), private drugstores (n=15), and on 60 non official drug shops randomly chosen in the city. Despite a limited efficacy at the time of the survey, chloroquine remained widely available in the official and non official markets. Artemisinin derivatives used in monotherapy or in combination were commonly sold. In health care facilities, 93 % of the uncomplicated malaria cases were treated in the absence of any laboratory confirmation and the officially recommended treatment, amodiaquine-sulfadoxine/pyrimethamine was seldom prescribed. Thus, the national guidelines for the treatment of uncomplicated malaria are not followed by health professionals in Bangui. Its use should be implemented while a control of importation of drug has to be reinforced. [ABSTRACT FROM AUTHOR]

The ultimate goal of toxicologic investigation of synthetic vitreous fibers (SVFs) is to provide essential input for the assessment of human risk to their exposure. Toxicity of mineral fibers is usually evaluated by testing biopersistence in rodent model. However, a cellular model would be much appreciated in order to reduce, refine, and replace animal models. Pulmonary disorders triggered by inhalation of occupational or environmental mineral particulates can be the endpoints of a chronic inflammatory process in which alveolar macrophages (AMs) play a crucial role. Depending on the type of SVF involved, phagocytosis of fiber leads to activation of macrophages, resulting in release of fiber components and potent mediators, such as reactive oxygen or nitrogen species and cytokines. As a matter of fact, macrophages should be the cells of choice since SVF toxicity is the consequence of fibers and alveolar macrophages interaction. Today, monocytes and macrophages culture are firmly established as a paradigm in toxicology when several endpoints are assayed in macrophages: (1) fiber durability, (2) fiber surface changes, (3) oxidative stress and genotoxicity in macrophage, and (4) macrophage cell viability and apoptosis. This article is a review of up-to-date knowledge of in vitro studies involving macrophages, and assesses endpoints of macrophage toxicity with an emphasis on (1) dissolution, (2) scanning electron microscopy analysis, (3) cytotoxicity, and (4) gene expression. [ABSTRACT FROM AUTHOR]

The toxicity of the compounds currently used in the treatment of human cytomegalovirus (HCMV) infections in immunocompromised hosts may force the treatment to be discontinued. The aim of this study was to improve the antiviral activity of ganciclovir (GCV), one the most widely used drug, by complexing it with β-cyclodextrin. Cyclodextrins (cds) have the property to form inclusion complexes with a great number of molecules and to enhance bioavailability and biological properties of these molecules. In this study, we investigated the in vitro antiviral activity of complexed GCV against several strains of HCMV: AD169, a reference strain, RCL-1, a laboratory mutant resistant to GCV, and four clinical isolates. The complexed GCV was more effective than free GCV against all HCMV strains tested. Cds as carriers for antiviral drugs would represent a useful adjunct to classical treatment procedures. They may make it possible to administer lower doses, thus reducing the toxic side effects of the drugs. [Copyright &y& Elsevier]

• Rubella epidemiology in the Central African Republic from 2015 to 2016 was studied • Nearly half of the investigated sera were rubella IgM positive • Most cases (95.1%) occurred between January and April • Most patients were between 5 and 9 years old (50.2%) • Genotypes 1E, 1G and 2B were identified in samples collected between 2008 and 2016 Objectives: Rubella cases in the Central African Republic (CAF) are currently identified during measles surveillance. This study aimed to investigate rubella epidemiology between 2015 and 2016 and to provide baseline genotype data for monitoring future rubella control efforts. Methods: 831 measles IgM negative or equivocal sera from 2015/2016 were tested for rubella IgM antibodies and 350 rubella IgM positive sera collected between 2008 and 2016 were selected for PCR and sequencing. Results: 411 of the 831 sera (49.5%) were rubella IgM positive and most cases (n=391, 95.1%) occurred between January and April. Most patients were between 5 and 9 years old (50.2%) and more than half of the rubella cases (56.7%) originated from the capital Bangui. Genotype information was obtained for 37 of the 350 selected rubella IgM-positive specimens, with the majority of the patients originating from Bangui (n=24, 64.9%) and sequences covering all years except 2009. Phylogenetic analysis identified genotypes 1E (n=12), 1G (n=5) and 2B (n=20), with 2B being detected from 2014 onwards. Conclusions: Our study confirmed the important role of rubella as a rash and fever disease in CAF and provided comprehensive data on rubella epidemiology and the first information on rubella genotypes in the country. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "S-Nitrosoglutathione (GSNO) Is Cytotoxic to Intracellular Amastigotes and Promotes Healing of Topically Treated Leishmania major or Leishmania braziliensis Skin Lesions," by I. S. F. Costa, G. F. P Souza, M. G. Oliveira and others, which appeared in a 2013 issue.

The pulmonary toxicological properties of inhaled titanium dioxide were studied using bronchoalveolar lavage fluid (BALF) cytology and proteomics analyses. Fischer 344 rats were exposed to 10 mg/m3 of TiO 2 nanostructured aerosol by nose-only inhalation for 6 h/day, 5 days/week for 4 weeks. Lung samples were collected up to 180 post-exposure days. As previously described, cytological analyses of BALF showed a strong inflammatory response up to 3 post-exposure days, which persisted however, at a lower intensity up to 180 days. In addition, using Multidimensional Protein Identification Technology (MudPIT), we identified a total of 107, 50 and 45 proteins (UniprotKB identifiers) differentially expressed in exposed rats immediately, 3 and 180 days after the end of exposure respectively. Increased levels of inflammatory proteins, members of proteasome, various histones, proteins involved in cytoskeleton organization, were noticed up to 3 days (short-term response). Some of these proteins were linked with Neutrophil Extracellular Trap formation (NETosis). Long-term response was also characterized by a persistent altered expression of proteins up to 180 days. Altogether, these results suggest that exposure to low toxicity low solubility nanomaterials such as TiO 2 may induce long-term changes in the pulmonary protein expression pattern of which the physio-pathological consequences are unknown. This paper describes in rats, at the pulmonary level, the effects of inhaled nanostructured aerosol of TiO 2 on the secreted proteins found in the broncho-alveolar space by comparing the proteomic profile in broncho-alveolar lavage fluid supernatants of control and exposed animals. This work brings new insights about the early events occurring following the end of exposure and suggests the formation of Neutrophil Extracellular Traps (NETosis) that could be interpret as a potential early mechanism of defense against TiO 2 nanoparticles. This work also describes the long term effects (180 post-exposure days) of such an exposure and the change in secreted protein expression in the absence of significant histopathological modifications. Unlabelled Image • BALF proteomics to assess pulmonary toxicity of inhaled TiO 2 in rats • TiO 2 induced proteins and biological processes associated with acute inflammation. • Proteins associated with NETosis found in BALF of exposed rats. • Proteins and biological processes still modified at 180 post-exposure days. • Such study may help identifying markers of particles exposure or effects. [ABSTRACT FROM AUTHOR]

Introduction. The number of Salmonella isolated from clinical samples that are resistant to multiple antibiotics has increased worldwide. The aim of this study was to determine the prevalence of resistant Salmonella enterica isolated in Bangui. Methods. All enteric Salmonella strains isolated from patients in 2008 were identified and serotyped, and the phenotypes of resistance were determined by using the disk diffusion method. Nine resistance-associated genes, blaTEM, blaOXA, blaSHV, tetA, aadA1, catA1, dhfrA1, sul I, and sul II, were sought by genic amplification in seven S.e. Typhimurium strains. Results. The 94 strains isolated consisted of 47 S.e. Typhimurium (50%), 21 S.e. Stanleyville (22%), 18 S.e. Enteritidis (19%), 4 S.e. Dublin (4%), 4 S.e. Hadar (4%), and 1 S.e. Papuana (1%). Twenty-five (28%) were multiresistant, including 20 of the Typhimurium serovar (80%). Two main phenotypes of resistance were found: four antibiotics (56%) and to five antibiotics (40%). One S.e. Typhimurium isolate produced an extended-spectrum β-lactamase (ESBL). Only seven strains of S.e. Typhimurium could be amplified genically. Only phenotypic resistance to tetracycline and aminosides was found. Conclusion. S. Typhimurium is the predominant serovar of enteric S. enterica and is the most widely resistant. The search for resistance genes showed heterogeneity of the circulating strains. [ABSTRACT FROM AUTHOR]

Background: As most data on hepatitis in resource-poor countries relate to urban communities, surveys in the rural environment are necessary to determine the 'true' prevalence of these viral infections. We undertook a survey to determine the prevalence of hepatitis B virus (HBV) infection in an apparently healthy rural population in the Central African Republic (CAR). Methods: The cross-sectional study was based on dried blood spots (DBS) from 273 people recruited in four prefectures (Lobaye, Nana-Mambéré, Ouham and Ouaka). Eluates from DBS were tested with commercial ELISA kits to detect markers of HBV infection. DBS were directly used for DNA extraction, followed by PCR and genotyping based on preS/S gene sequences. Results: The overall prevalence of HBc antibodies was 27.1% (Lobaye 29%, Nana-Mambéré 28%, Ouaka 29% and Ouham 23%) and that of HBsAg was 10.6% (Lobaye 9%, Nana-Mambéré 9%, Ouaka 19% and Ouham 8%), with no statistically significant difference among the surveyed communities. Nineteen sequences obtained from 74 anti-HBc-positive patients all belonged to genotype E. Risk factor analysis of HBV infection pointed to sexual transmission of the virus. Conclusion: The prevalence of HBV is high in rural communities in the CAR and comparable to that observed in urban areas. In addition, genotype E is prevalent in these areas. These findings underline the importance of instituting a programme of active HBV surveillance and vaccination of the population. [ABSTRACT FROM AUTHOR]

Background: We evaluated whether B cell-derived immune defenses of the gastro-intestinal tract are activated to produce HIV-specific antibodies in children continuously exposed to HIV via breast-feeding. Methods: Couples of HIV-1-infected mothers (n = 14) and their breastfed non HIV-infected (n = 8) and HIV-infected (n = 6) babies, and healthy HIV-negative mothers and breastfed babies (n = 10) as controls, were prospectively included at the Complexe Pédiatrique of Bangui, Central African Republic. Immunoglobulins (IgA, IgG and IgM) and anti-gp160 antibodies from mother’s milk and stools of breastfed children were quantified by ELISA. Immunoaffinity purified anti-gp160 antibodies were characterized functionally regarding their capacity to reduce attachment and/or infection of R5- and X4- tropic HIV-1 strains on human colorectal epithelial HT29 cells line or monocyte-derived-macrophages (MDM). Results: The levels of total IgA and IgG were increased in milk of HIV-infected mothers and stools of HIV-exposed children, indicating the activation of B cell-derived mucosal immunity. Breast milk samples as well as stool samples from HIV-negative and HIV-infected babies exposed to HIV by breast-feeding, contained high levels of HIV-specific antibodies, mainly IgG antibodies, less frequently IgA antibodies, and rarely IgM antibodies. Relative ratios of excretion by reference to lactoferrin calculated for HIV-specific IgA, IgG and IgM in stools of HIV-exposed children were largely superior to 1, indicating active production of HIV-specific antibodies by the intestinal mucosa. Antibodies to gp160 purified from pooled stools of HIV-exposed breastfed children inhibited the attachment of HIV-1NDK on HT29 cells by 63% and on MDM by 77%, and the attachment of HIV-1JRCSF on MDM by 40%; and the infection of MDM by HIV-1JRCSF by 93%. Conclusions: The intestinal mucosa of children exposed to HIV by breast-feeding produces HIV-specific antibodies harbouring in vitro major functional properties against HIV. These observations lay the conceptual basis for the design of a prophylactic vaccine against HIV in exposed children. [ABSTRACT FROM AUTHOR]

Background: Although chicken anemia virus (CAV) has been detected on all continents, little is known about this virus in sub-Saharan Africa. This study aimed to detect and characterize CAV for the first time in Central African Republic and in Cameroon. Results: An overall flock seroprevalence of 36.7% was found in Central African Republic during the 2008-2010 period. Virus prevalences were 34.2% (2008), 14.3% (2009) and 10.4% (2010) in Central African Republic and 39% (2007) and 34.9% (2009) in Cameroon. CAV DNA was found in cloacal swabs of 76.9% of seropositive chickens, suggesting that these animals excreted the virus despite antibodies. On the basis of VP1 sequences, most of the strains in Central African Republic and Cameroon belonged to 9 distinct phylogenetic clusters at the nucleotide level and were not intermixed with strains from other continent. Several cases of mixed infections in flocks and individual chickens were identified. Conclusions: Our results suggest multiple introductions of CAV in each country that later spread and diverged locally. Mixed genotype infections together with the observation of CAV DNA in cloacal samples despite antibodies suggest a suboptimal protection by antibodies or virus persistence. [ABSTRACT FROM AUTHOR]

Background: Both treatment and prevention strategies are recommended by the World Health Organization for the control of malaria during pregnancy in tropical areas. The aim of this study was to assess use of a rapid diagnostic test for prompt management of malaria in pregnancy in Bangui, Central African Republic. Methods: A cohort of 76 pregnant women was screened systematically for malaria with ParacheckPf® at each antenatal visit. The usefulness of the method was analysed by comparing the number of malaria episodes requiring treatment in the cohort with the number of prescriptions received by another group of pregnant women followed up in routine antenatal care. Results: In the cohort group, the proportion of positive ParacheckPf® episodes during antenatal clinics visits was 13.8%, while episodes of antimalarial prescriptions in the group which was followed-up routinely by antenatal personnel was estimated at 26.3%. Hence, the relative risk of the cohort for being prescribed an antimalarial drug was 0.53. Therefore, the attributable fraction of presumptive treatment avoided by systematic screening with ParacheckPf® was 47%. Conclusions: Use of a rapid diagnostic test is useful, affordable and easy for adequate treatment of malaria in pregnant women. More powerful studies of the usefulness of introducing the test into antenatal care are needed in all heath centres in the country and in other tropical areas. [ABSTRACT FROM AUTHOR]

Introduction. The aim of this study was to estimate the prevalence of malaria among women giving birth in Bangui. Association between sociodemographic characteristics of those women and malaria, as well as prevention compliance (use of intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTsp) and insecticide-treated bed nets (ITNs)), was analyzed. Methods. During September 2009, a survey was conducted on 328 women who gave birth at two main maternities of Bangui. Information was obtained by standardized questionnaire about sociodemographic criteria, IPTsp, other antimalarial treatment, and use of bet nets. Smears prepared from peripheral and placental blood were analysed for malaria parasites. Findings and Discussion. Positive results were found in 2.8% of thick peripheral blood smears and in 4.0% of placental slides. A proportion of 30.5% of the women had received at least two doses of IPTsp during the current pregnancy. Only a proportion of 42.4% of this study population had ITNs. Multigravid women were less likely to use IPTsp and ITNs. However, use of IPTsp was associated with personal income and secondary or university educational status. Hence, although this relatively prevalence was observed, more efforts are needed to implement IPTsp and ITNs, taking into account sociodemographic criteria. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B virus (HBV) is the major cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. The global epidemiological scenario of HBV infection has been changing rapidly over the last two decades due to an effective immunization programme initiated by the World Health Organization. The objective of this study is to estimate the prevalence of HBV in apparently healthy young people and to identify the risk factors of transmission of the HBV among this population in Bangui. Methods: Dried blood Spots from 801 adolescent high school and young adult university students were prepared by spotting a drop of whole blood (4 spots) from the same fingerprick onto Whatman filter paper. A blood sample aliquot eluted from DBS was then processed with commercial ELISA tests (Abbott Murex, Dartfort, UK) to detect HBsAg antigen, Anti-HBc and Anti-HBs antibodies). Results: The overall prevalence was 42.3% for antibody to hepatitis B core antigen, 15.5% for HBsAg of which 1.3% of HBsAg alone. HBV familial antecedents, sexual activity and socioeconomic conditions were the main risk factors of HBV infection encountered in the adolescents and young adults. Conclusion: These results show for the first time the high prevalence of HBV in apparently healthy young people in Bangui. This high prevalence is age- and sex-independent. Transmission risk factors were a familial antecedent of HBV, no utilisation of condoms and public scholarship. To lower HBV prevalence, an adequate program of active screening and vaccination for adolescents and young adults should be implemented, along with a universal immunization program. [ABSTRACT FROM AUTHOR]

Background: Because of the previous high prevalence of resistance to usual antibiotics among uropathogens in Bangui, Central African Republic (CAR), a survey focused on Enterobacteriaceae, the most prevalent group responsible for urinary tract infections (UTIs), was conducted. The aim was to help health authorities revise antibiotic policies. Methodology: We performed a retrospective analysis of all cases of confirmed UTIs due to Enterobacteriaceae in outpatients attending the Institut Pasteur de Bangui (IPB), CAR, between 2004 and 2006. Results: During the study period, 560 (10.9% of urine submissions) UTIs were confirmed and 443 Enterobacteriaceae strains were isolated, representing 79% of the causative agents for UTIs. Among these 560 strains, E. coli was the most common, representing 64% of the isolates, followed by K. pneumoniae (10%) and other Enterobacteriaceae (5%). Extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae significantly increased from five (3.7%) to thirty-three (19.3%) between 2004 and 2006. A significantly increased resistance rate to nalidixic acid, ciprofloxacin and gentamicin was observed in ESBL-nonproducing Enterobacteriaceae over the study period. Conclusions: Empiric treatment for UTIs in Bangui should be reconsidered and prudent use of antibiotics, particularly ciprofloxacin, is highly recommended. The recent spread of ESBL-producing Enterobacteriaceae in central African outpatients is striking and underlines the need for further studies. [ABSTRACT FROM AUTHOR]

The toxicity of mineral fibers, whether they are natural or man made (MMMF), is usually evaluated in vivo using biopersistence tests in rodents. Development of an in vitro cellular model would be worthwhile in order to reduce, refine and finally replace animal models. For this purpose, we developed an in vitro assay using human monocytic cell line (U-937) to evaluate a new manufactured rock wool fiber (HDN) biodegradation. Experiments on earlier known mineral fibers asbestos (crocidolite) and glass wool fibers (CM44) were also performed. U-937 responded to HDN and CM44 only if they were activated. Among the different activators we used, Escherichia coli living cells as well as FS were the most efficient as evidenced by alterations of HDN and CM44 surface, detected by scanning electron microscopy, and by the measure of silicon released from the rock wool fibers. Asbestos fibers were not degraded when incubated in the presence of living bacteria. The MMMF modifications were function of the fiber composition, the time of exposure to activated cells and the concentration of activators. The pattern of MMMF degradation by our in vitro system was in accordance with those observed in an in vivo study, thus indicating that the fiber degradation by macrophage cells activated by E. coli living cells as well as FS is a valuable system to assess mineral fibers’ biopersistence. [ABSTRACT FROM AUTHOR]

A human monocytes cell line, U-937, incubated in the presence of filtered medium from Escherichia coli culture (FS) has been previously reported to degrade man made mineral fiber and it has been indicated as a good paradigm of in vivo fiber biopersistence evaluation (manuscript accepted for publication). In the present paper, a study is reported aimed to define the molecular modification occurring in the U-937 monocytes during in vitro fiber degradation. The induction of gene expression was investigated in U-937 exposed to rock wool fibers (HDN) in the presence of FS by transcriptome analysis using 20 K DNA microarrays and quantitative RT-PCR. The over-expression of genes related to mobility and cellular adhesion, oxidative stress, immune system stimulation, enzymes, and ions transport protein systems were identified. Among them NCF1 gene, the gene encoding a subunit of NADPH oxidase, over-expression was detected. As the product of this gene allows the formation of superoxide anion that could lead to oxidative stress, HDN fibers were exposed to hydrogen peroxide. Fiber degradation similar to those observed upon incubation with U-937 in the presence of FS was obtained thus suggesting that reactive oxygen species production may be responsible for fiber degradation by U-937 monocytes. [ABSTRACT FROM AUTHOR]

Background/Aims: Homocysteine metabolism is linked to DNA methylation, a mechanism potentially involved in the course of hepatitis B virus (HBV) infection. We evaluated the association of determinants of homocysteine metabolism with the outcome of HBV infection. Methods: Four hundred and fifty-five healthy adults from Togo and Benin were tested for HBV serologic markers, HLA DR alleles, folate, vitamin B12, methylenetetrahydrofolate reductase (MTHFR) 677 C→T, 1298 A→C and methionine synthase 2756 A→G polymorphisms. Results: Seventy-eight percent of the study population was anti-HBc positive. Among them, 202 (56.9%) were anti-HBs positive and 58 (16.3%) were HBsAg positive. After stepwise logistic regression, the MTHFR 677 T allele was independently associated with persistence of detectable anti-HBs antibodies (OR: 2.47; 95% CI: 1.29–4.71; p =0.006). The mean HBV DNA level was significantly lower in HBsAg positive subjects carrying the 677 T allele than in those with the 677 CC genotype (1000±1406 vs. 2,400,000±214,000 copies/ml, p =0.005). Beninese origin and HLA-DRB1*09 allele were the other determinants independently associated with favorable outcome of HBV infection. Conclusions: The methylenetetrahydrofolate reductase 677 T allele seems to protect against chronic HBV infection in young African adults. [Copyright &y& Elsevier]

Abstract: Background: Recent studies have shown that Hepatitis B virus (HBV) genotype E predominates in a vast crescent in West-Africa spanning from Senegal to Angola. Objectives: To determine whether HBV strains in the Central African Republic (CAR) belong predominately to the homogeneous West-African genotype E or whether they are more closely related to genotypes found in East Africa. Study design: Serum samples were randomly collected from 196 patients admitted with symptoms of acute or chronic hepatitis to the Central Hospital in Bangui. Thirty complete and 36 partial sequences of HBV strains were obtained. Results: Ninety-four percent (62/66) of the strains belonged to genotype E, while genotype A1, most closely related to a strain from Tanzania and genotype D were detected in only one and three samples, respectively. One strain presented a recombination between the S and X gene of a genotype E precursor and a partial PreC/C gene of a genotype D precursor. Conclusions: Genotype E is predominant in CAR with little overlap with genotypes from Eastern Africa, extending the West-African HBV genotype E crescent further to the East. [Copyright &y& Elsevier]

Evaluating the pathogenic potentials of man-made mineral fibers (MMMF) is an important task performed by the European Community. Noting that it has been proposed that the use of laboratory animals for scientific tests should be reduced or phased out, macrophages then become the cells of choice for conducting in vitro studies. We have evaluated the in vitro toxicity of six commercial stonewool fibers (A, B1, B2, C, D, and E) on U-937 cells. The physical interaction between U-937 cells and MMMF was observed using scanning electron microscopy, and the cytotoxicity was evaluated by studying cell viability using MTT assay and cell apoptosis with an ELISA detection kit. Scanning electron microscopy (SEM) analysis has shown that long fibers can be covered by several macrophages, and that a small fiber can be completely engulfed by one cell. With 50 μg/mL of MMMF, a decrease in cell viability appeared after seven days of incubation, whereas 200 μg/mL induced loss of viability and apoptosis after one day. Fiber D, comprising a high proportion of fibers >20 μm in length and a high concentration of MgO, induced the highest loss in viability and the highest rate of apoptosis compared to the other five fibers. Whether this toxic effect is related to either the physical characteristics of the fibers (such as length), or to the high concentration of magnesium is still to be determined. Because the results can be rapidly obtained, the proposed model is suitable for studying the toxicities of mineral components, even if the tested concentrations are far from the ones reached in the lung. [ABSTRACT FROM AUTHOR]

The common observation of Epstein-Barr virus (EBV) viremia in pediatric recipients of renal transplants and the occurrence of an EBV-related pulmonary leiomyoma prompted us to intensify the follow-up of EBV infections from 1995 to October 2000. Follow-up included serology and detection of viral DNA in blood using a semi-quantitative nested polymerase chain reaction (PCR) and later a real-time PCR with higher sensitivity. The aim of this study was the early detection of primary infections or reactivations. We obtained 250 samples from 32 patients. EBV DNA detection was consistently negative in 14 patients. There were 5 patients that were considered at risk for post-transplant lymphoproliferative disease, as they were EBV seronegative and were given a kidney from a positive donor. Of these, 4 had at least one episode of high-level EBV viremia. During these episodes, an absence of noticeable symptoms that could be related to EBV was noted for all but 1 patient. This child presented with severe neutropenia 1 month after grafting and, 28 months later, several nodules of pulmonary leiomyoma, which were found to be EBV related. Four episodes of high-level viremia were observed before the discovery of the leiomyoma. Viral DNA detection is important for the follow-up of such patients that are especially at risk of serious complications of EBV infections. [ABSTRACT FROM AUTHOR]

We have searched for sulfate-reducing bacteria in the feces of 41 healthy individuals and 110 patients from a Hepato-Gastro-Enterology Unit using a specific liquid medium (Test-kit Labe&grave;ge®, Compagnie Franc¸aise de Ge´othermie, Orle´ans, France). The 110 patients were separated in 22 patients presenting with inflammatory bowel diseases and 88 patients hospitalized for other lower (n=30) or upper (n=58) digestive tract diseases. Sulfate-reducing bacteria were isolated from 10 healthy individuals (24%), 15 patients presenting with inflammatory bowel diseases (68%), and 33 patients with other symptoms (37%). A multiplex PCR was devised for the identification of Desulfovibrio piger (formerly Desulfomonas pigra), Desulfovibrio fairfieldensis and Desulfovibrio desulfuricans, and applied to the above isolates. The strains of sulfate-reducing bacteria consisted of D. piger (39 isolates), D. fairfieldensis (19 isolates) and D. desulfuricans (one isolate). The prevalence of D. piger was significantly higher in inflammatory bowel disease patients (55%) as compared to healthy individuals (12%) or patients with other symptoms (25%) (P<0.05). [Copyright &y& Elsevier]

Provides information on a study which discussed the treatment of adenovirus infection in patients undergoing allogeneic hematopoietic stem cell transplantation. Research patients and methods; Results in the treated and untreated groups; Risk factors for treatment failure.

In nanomedicine, hybrid nanomaterials stand out for providing new insights in both the diagnosis and treatment of several diseases. Once administered, engineered nanoparticles (NPs) interact with biological molecules, and the nature of this interaction might directly interfere with the biological fate and action of the NPs. In this work, we synthesized a hybrid magnetic nanostructure, with antibacterial and antitumoral potential applications, composed of a magnetite core covered by silver NPs, and coated with a modified chitosan polymer. As magnetite NPs readily oxidize to maghemite, we investigated the structural properties of the NPs after addition of the two successive layers using Mössbauer spectroscopy. Then, the structural characteristics of the NPs were correlated to their interaction with albumin, the major blood protein, to evidence the consequences of its binding on NP properties and protein retention. Thermodynamic parameters of the NPs–albumin interaction were determined. We observed that the more stable NPs (coated with modified chitosan) present a lower affinity for albumin in comparison to pure magnetite and magnetite/silver hybrid NPs. Surface properties were key players at the NP–biological interface. To the best of our knowledge, this is the first study that demonstrates a correlation between the structural properties of complex hybrid NPs and their interaction with albumin. [ABSTRACT FROM AUTHOR]

The article describes a study which conducted a passive survey in the hospitals of Bangui in Central African Republic, to confirm cases of Buruli ulcer in the region. The survey reveals two confirmed cases of Buruli ulcer. The patients, both farmers from the Ombella M'poko region, were admitted to Hôpital de l'Amitié in Bangui after exhibiting extensive skin ulcers. Researchers emphasize the importance that the public health authorities be trained and informed to identify the disease in the early stages.

Background: As most data on hepatitis in resource-poor countries relate to urban communities, surveys in the rural environment are necessary to determine the 'true' prevalence of these viral infections. We undertook a survey to determine the prevalence of hepatitis B virus (HBV) infection in an apparently healthy rural population in the Central African Republic (CAR).Methods: The cross-sectional study was based on dried blood spots (DBS) from 273 people recruited in four prefectures (Lobaye, Nana-Mambéré, Ouham and Ouaka). Eluates from DBS were tested with commercial ELISA kits to detect markers of HBV infection. DBS were directly used for DNA extraction, followed by PCR and genotyping based on preS/S gene sequences.Results: The overall prevalence of HBc antibodies was 27.1% (Lobaye 29%, Nana-Mambéré 28%, Ouaka 29% and Ouham 23%) and that of HBsAg was 10.6% (Lobaye 9%, Nana-Mambéré 9%, Ouaka 19% and Ouham 8%), with no statistically significant difference among the surveyed communities. Nineteen sequences obtained from 74 anti-HBc-positive patients all belonged to genotype E. Risk factor analysis of HBV infection pointed to sexual transmission of the virus.Conclusion: The prevalence of HBV is high in rural communities in the CAR and comparable to that observed in urban areas. In addition, genotype E is prevalent in these areas. These findings underline the importance of instituting a programme of active HBV surveillance and vaccination of the population. [ABSTRACT FROM AUTHOR]

Background: Both treatment and prevention strategies are recommended by the World Health Organization for the control of malaria during pregnancy in tropical areas. The aim of this study was to assess use of a rapid diagnostic test for prompt management of malaria in pregnancy in Bangui, Central African Republic.Methods: A cohort of 76 pregnant women was screened systematically for malaria with ParacheckPf® at each antenatal visit. The usefulness of the method was analysed by comparing the number of malaria episodes requiring treatment in the cohort with the number of prescriptions received by another group of pregnant women followed-up in routine antenatal care.Results: In the cohort group, the proportion of positive ParacheckPf® episodes during antenatal clinics visits was 13.8%, while episodes of antimalarial prescriptions in the group which was followed-up routinely by antenatal personnel was estimated at 26.3%. Hence, the relative risk of the cohort for being prescribed an antimalarial drug was 0.53. Therefore, the attributable fraction of presumptive treatment avoided by systematic screening with ParacheckPf® was 47%.Conclusions: Use of a rapid diagnostic test is useful, affordable and easy for adequate treatment of malaria in pregnant women. More powerful studies of the usefulness of introducing the test into antenatal care are needed in all heath centres in the country and in other tropical areas. [ABSTRACT FROM AUTHOR]