Prevalence and intensity of infections of Ascaris lumbricoides and Trichuris trichiura and associated socio-demographic variables in four rural Honduran communities

Between January and March 1998, a cross-sectional survey was carried out in four rural communities in Honduras, Central America. We examined the prevalence and intensity of Ascaris lumbricoides and Trichuris trichiura infections among 240 fecal specimens, and the association between selected socio-demographic variables and infection for 62 households. The overall prevalence of A. lumbricoides and T. trichiura was 45% (95% CI 39.0-51.9) and 38% (95% CI 31.8-44.4) respectively. The most intense infections for Ascaris and Trichuris were found in children aged 2-12 years old. By univariate analysis variables associated with infections of A. lumbricoides were: number of children 2-5 years old (p=0.001), level of formal education of respondents (p=0.01), reported site of defecation of children in households (p=0.02), households with children who had a recent history of diarrhea (p=0.002), and the location of households (p=0.03). Variables associated with both A. lumbricoides and T. trichiura infection included: number of children 6-14 years old (p=0.01, p=0.04, respectively), ownership of a latrine (p=0.04, p=0.03, respectively) and coinfection with either helminth (p=0.001, p=0.001, respectively). By multivariate analysis the number of children 2-5 years living in the household, (p=0.01, odds ratio (OR)=22.2), children with a recent history of diarrhea (p=0.0, OR=39.8), and infection of household members with T. trichiura (p=0.02, OR=16.0) were associated with A. lumbricoides infection. The number of children 6-14 years old in the household was associated with both A. lumbricoides and T. trichiura infection (p=0.04, p=0.01, OR=19.2, OR=5.2, respectively).

Diethyldithiocarbamic acid inhibits the octadecanoid signaling pathway for the wound induction of proteinase-inhibitors in tomato leaves

The induction of proteinase inhibitor I synthesis in tomato (Lycopersicon esculentum) leaves in response to wounding is strongly inhibited by diethyldithiocarbamic acid (DIECA). DIECA also inhibits the induction of inhibitor I synthesis by the 18-amino acid polypeptide systemin, polygalacturonic acid (PCA), and linolenic acid, but not by jasmonic acid, suggesting that DIECA interferes with the octadecanoid signaling pathway. DIECA only weakly inhibited tomato lipoxygenase activity, indicating that DIECA action occurred at a step after the conversion of linolenic acid to 13(S)-hydroperoxylinolenic acid (HPOTrE). DIECA was shown to efficiently reduce HPOTrE to 13-hydroxylinolenic acid (HOTrE), which is not a signaling intermediate. Therefore, in vivo, DIECA is likely inhibiting the signaling pathway by shunting HPOTrE to HOTrE, thereby severely reducing the precursor pool leading to cyclization and eventual synthesis of jasmonic acid. Phenidone, an inhibitor of lipoxygenase, inhibited proteinase inhibitor I accumulation in response to wounding, further supporting a role for its substrate, linolenic acid, and its product, HPOTrE, as components of the signal-transduction pathway that induces proteinase inhibitor synthesis in response to wounding, systemin, and PCA.

Antifungal resistance and new strategies to control fungal infections.

Despite improvement of antifungal therapies over the last 30 years, the phenomenon of antifungal resistance is still of major concern in clinical practice. In the last 10 years the molecular mechanisms underlying this phenomenon were extensively unraveled. In this paper, after a brief overview of currently available antifungals, molecular mechanisms of antifungal resistance will be detailed. It appears that major mechanisms of resistance are essential due to the deregulation of antifungal resistance effector genes. This deregulation is a consequence of point mutations occurring in transcriptional regulators of these effector genes. Resistance can also follow the emergence of point mutations directly in the genes coding antifungal targets. In addition we further describe new strategies currently undertaken to discover alternative therapy targets and antifungals. Identification of new antifungals is essentially achieved by the screening of natural or synthetic chemical compound collections. Discovery of new putative antifungal targets is performed through genome-wide approaches for a better understanding of the human pathogenic fungi biology.

Le Groupe Prévention et Traitement des Plaies des Hospices-CHUV [The Hospices-CHUV's Wound Prevention and Treatment Group]

The treatment of wounds is a challenge that caregivers of all specialities encounter daily in the care of an ageing population and chronically ill patients. An interdisciplinary group has been created in recent years within the Hospices-CHUV to assist caregivers in their care of patients with wounds. This group has developed a variety of tools to assist decision-making and offers a range of continuing education for those employees involved in wound care. The authors describe the approach of the group and the documents produced during the first two years of experience.

Mapping the Issues: HIV and Other Sexually Transmitted Infections in the United Kingdom 2005

Mapping the Issues: HIV and Other Sexually Transmitted Infections in the United Kingdom 2005

Differential time to positivity of blood cultures: a valid method for diagnosing catheter-related bloodstream infections in the intensive care unit

iii. Catheter-related bloodstream infection (CR-BSI) diagnosis usually involves catheter withdrawal. An alternative method for CR-BSI diagnosis is the differential time to positivity (DTP) between peripheral and catheter hub blood cultures. This study aims to validate the DTP method in short-term catheters. The results show a low prevalence of CR-BSI in the sample (8.4%). The DTP method is a valid alternative for CR-BSI diagnosis in those cases with monomicrobial cultures (80% sensitivity, 99% specificity, 92% positive predictive value, and 98% negative predictive value) and a cut-off point of 17.7 hours for positivity of hub blood culture may assess in CR-BSI diagnosis.

Colite à Clostridium difficile: nouvelles recommandations de prise en charge [Clostridium difficile infections: update on new European recommendations].

Clostridium difficile infections: update on new European recommandations While metronidazole and vancomycin have been the only drug options to date for the treatment of C. difficile infection, new therapeutic approaches with promising results have recently emerged for the treatment of the first episode and relapses. Fidaxomicin is a new macrocyclic antibiotic more active against C. difficile and with a narrow spectrum allowing preservation of the intestinal microbiota. While having the same efficacy as vancomycin for the treatment of the first episode, this agent is associated with a lower rate of relapse. The highest relapse-free cure rate is achieved through fecal microbiota transplantation, which should be considered for patients with multiple relapses.

Leishmania (Leishmania) major-infected rhesus macaques (Macaca mulatta) develop varying levels of resistance against homologous re-infections

Seven rhesus macaques were infected intradermally with 10(7) promastigotes of Leishmania (Leishmania) major. All monkeys developed a localized, ulcerative, self-healing nodular skin lesion at the site of inoculation of the parasite. Non-specific chronic inflammation and/or tuberculoid-type granulomatous reaction were the main histopathological manifestations of the disease. Serum Leishmania-specific antibodies (IgG and IgG1) were detected by ELISA in all infected animals; immunoblot analyses indicated that numerous antigens were recognized. A very high degree of variability was observed in the parasite-specific cell-mediated immune responses [as detected by measuring delayed-type hypersensitivity (DTH) reaction, in vitro lymphocyte proliferation, and gamma interferon (IFN-gamma) production] for individuals over time post challenge. From all the recovered monkeys (which showed resolution of the lesions after 11 weeks of infection), 57.2% (4/7) and 28.6% (2/7) animals remained susceptible to secondary and tertiary infections, respectively, but the disease severity was altered (i.e. lesion size was smaller and healed faster than in the primary infection). The remaining monkeys exhibited complete resistance (i.e. no lesion) to each rechallenge. Despite the inability to consistently detect correlates of cell-mediated immunity to Leishmania or correlation between resistance to challenge and DTH, lymphocyte transformation or IFN-gamma production, partial or complete acquired resistance was conferred by experimental infection. This primate model should be useful for measuring vaccine effectiveness against the human disease.

A new continuous cell line from the mosquito Psorophora confinnis (Diptera: Culicidae) and its susceptibility to infections with some arboviruses

A new cell line, PC-0199-BR, was established from embryonated eggs of the mosquito Psorophora confinnis. To date (September 2000) it has had 62 continuous passages. This is the first report of a cell line of mosquitoes belonging to the genus Psorophora. Cell growth initially was achieved in the MM/VP12 medium, supplemented with 20% fetal bovine serum; however, the subcultures were later adapted to Grace's medium with 10% fetal bovine serum. Cell morphology in the primary cultures was heterogeneous; but later in the established cell line, the predominant cell type was epithelioid. Cultured cells were predominantly diploid (2n=6); however, chromosome abnormalities were observed in a small proportion of the cells in later passages. C and G band patterns were also determined in the karyotype. The cell line isozyme profiles coincided with pupae and adult samples of the species taken from the same colony. A preliminary arbovirus susceptibility study for the cell line was undertaken. No evidence was observed of contamination of the cell line with bacteria, fungi or mycoplasma.

Plasmodium/intestinal helminth co-infections among pregnant Nigerian women

Hospital based studies were conducted to investigate the occurrence of Plasmodium/intestinal helminth co-infections among pregnant Nigerian women, and their effects on birthweights, anaemia and spleen size. From 2,104 near-term pregnant women examined, 816 (38.8%) were found to be infected with malaria parasites. Among the 816 parasitaemic subjects, 394 (48.3%) were also infected with intestinal helminths, 102 (12.5%) having mixed helminth infections. The prevalence of the helminth species found in stool samples of parasitaemic subjects examined was, Ascaris lumbricoides (19.1%), hookworm (14.2%), Trichuris trichiura (7%) Schistosoma mansoni (3.4%), Enterobius vermicularis (2%), Hymenolepis sp. (1.6%) and Taenia sp. (1%). Mothers with Plasmodium infection but without intestinal helminth infection had neonates of higher mean birthweights than those presenting both Plasmodium and intestinal helminth infections and this effect was more pronounced in primigravids. The mean haemoglobin values of malarial mothers with intestinal helminth infections were lower than those with Plasmodium infection but without intestinal helminth infections but these were not statistically significant. Severe splenomegaly was predominant among parasitaemic gravidae who also harboured S. mansoni infection in two of the hospitals studied.

Species Diversity and Flagellate Infections in the Sand Fly Fauna near Porto Grande, State of Amapá, Brazil (Diptera: Psychodidae. Kinetoplastida: Trypanosomatidae)

Forty-six species of Lutzomyia and one species of Brumptomyia were identified among 20,008 sand flies collected in central Amapá. L. squamiventris maripaensis, L. infraspinosa, L. umbratilis and L. ubiquitalis accounted for 66% of the specimens caught in light traps, and L. umbratilis was the commonest of the 16 species found on tree bases. Seven species of Lutzomyia including L. umbratilis were collected in a plantation of Caribbean pine. Sixty out of 511 female sand flies dissected were positive for flagellates. Among the sand flies from which Leishmania was isolated, promastigotes were observed in the salivary glands and foregut of 13 out of 21 females scored as having very heavy infections in the remainder of the gut, reinforcing the idea that salivary gland invasion may be part of the normal life cycle of Leishmania in nature. Salivary gland infections were detected in specimens of L. umbratilis, L. whitmani and L. spathotrichia. Parasites isolated from L. umbratilis, L. whitmani and also from one specimen of L. dendrophyla containing the remains of a bloodmeal, were compatible with Le. guyanensis by morphology and behaviour in hamsters.

Reduction in catheter-related bloodstream infections in critically ill patients through a multiple system intervention.

Els catéters venosos centrals són necessaris per al maneig del pacient crític però poden ser l´origen d´una bacteriemia. Aquest estudi prospectiu de cohort té com a objectiu determinar la utilitat de l´aplicació d´unes mesures bàsiques de prevenció per disminuir la incidència de bacteriemia associada a catéter. Els resultats de l´estudi confirmen que l´aplicació d´aquest sistema d´intervenció múltiple basat en l´evidencia redueix de forma significativa les bacteriemies associades a catéter a la nostra UCI.

Nematode Infections Are Risk Factors for Staphylococcal Infection in Children

Nematode infection may be a risk factor for pyogenic liver abscess in children and we hypothesized that the immunomodulation induced by those parasites would be a risk factor for any staphylococcal infection in children. The present study was designed to compare, within the same hospital, the frequency of intestinal nematodes and Toxocara infection in children with and without staphylococcal infections. From October 1997 to February 1998, 80 children with staphylococcal infection and 110 children with other diseases were submitted to fecal examination, serology for Toxocara sp., evaluation of plasma immunoglobulin levels, and eosinophil counts. Mean age, gender distribution, birthplace, and socioeconomic conditions did not differ significantly between the two groups. Frequency of intestinal nematodes and positive serology for Toxocara, were remarkably higher in children with staphylococcal infections than in the non-staphylococcal group. There was a significant correlation between intestinal nematodes or Toxocara infection and staphylococcal infection in children, reinforced by higher eosinophil counts and higher IgE levels in these children than in the control group. One possible explanation for this association would be the enhancement of bacterial infection by the immunomodulation induced by helminth infections, due to strong activation of the Th2 subset of lymphocytes by antigens from larvae and adult worms.

Some Aspects of Protozoan Infections in Immunocompromised Patients: A Review

Protozoa are among the most important pathogens that can cause infections in immunocompromised hosts. These microorganisms particularly infect individuals with impaired cellular immunity, such as those with hematological neoplasias, renal or heart transplant patients, patients using high doses of corticosteroids, and patients with acquired immunodeficiency syndrome. The protozoa that most frequently cause disease in immunocompromised patients are Toxoplasma gondii, Trypanosoma cruzi, different Leishmania species, and Cryptosporidium parvum; the first two species cause severe acute meningoencephalitis and acute myocarditis, Leishmania sp. causes mucocutaneous or visceral disease, and Cryptosporidium can lead to chronic diarrhea with hepatobiliary involvement. Various serological, parasitological, histological and molecular methods for the diagnosis of these infections are currently available and early institution of specific therapy for each of these organisms is a basic measure to reduce the morbidity and mortality associated with these infections.

Infections nosocomiales : interventions et qualité des soins [Maladies infectieuses = Nosocomial infections : quality improvement interventions]

Le développement de méthodes de mesure de la qualité des soins et les actions visant à son amélioration font partie intégrante de la pratique quotidienne. Les infections nosocomiales représentent un Indicateur Incontournable et leur prévention apparaît comme un champ d'action privilégié du concept de l'amélioration continue de la qualité des soins. Dans ce domaine, de nombreuses mesures ont fait l'objet d'études répondant à des critères méthodologiques de qualité élevée, dont les résultats sont hautement significatifs au plan statistique. Les interventions complexes concernant par exemple l'ensemble des patients d'un service ou d'une institution ne permettent que difficilement de satisfaire à ces exigences méthodologiques. Sous certaines conditions, elle peuvent cependant avoir un impact réel et parfois durable sur la qualité des soins. A titre d'exemple, nous discutons deux interventions complexes dans le domaine de la prévention des infections nosocomiales, résultant de démarches visant à une amélioration globale et durable de la qualité des soins. L'utilisation d'outils épidémiologiques adaptés permet également d'estimer le bénéfice des Interventions en milieu hospitalier conformément à ce que la communauté scientifique reconnaît comme étant une recherche clinique de qualité.