Evaluation of Insecticide Resistance and Biochemical Mechanisms in a Population of Culex quinquefasciatus (Diptera: Culicidae) from São Paulo, Brazil

To establish an insecticidal resistance surveillance program, Culex quinquefasciatus mosquitoes from São Paulo, Brazil, were colonized (PIN95 strain) and analyzed for levels of resistance. The PIN95 strain showed low levels of resistance to organophosphates [malathion (3.3-fold), fenitrothion (11.2-fold)] and a carbamate [propoxur (3.0-fold)]. We also observed an increase of 7.4 and 9.9 in a and b esterase activities, respectively, when compared with the reference IAL strain. An alteration in the sensitivity of acetylcholinesterase to insecticide inhibition was also found in the PIN95 mosquitoes. The resistant allele (Ace.1R), however, was found at low frequencies (0.12) and does not play an important role in the described insecticide resistance. One year later, Cx. quinquefasciatus mosquitoes were collected (PIN96 strain) at the same site and compared to the PIN95 strain. The esterase activity patterns observed for the PIN96 strain were similar to those of the PIN95 mosquitoes. However the occurrence of the Ace.1R allele was statistically higher in the PIN96 strain. The results show that esterase-based insecticide resistance was established in the PIN95 Cx. quinquefasciatus population and that an acethylcholinesterase based resistant mechanism has been selected for. A continuous monitoring of this phenomenon is fundamental for rational mosquito control and insecticide application programs.

Spatio-temporal variations in reproductive patterns and population structure of Pasiphaea multidentata (Decapoda: Caridea) in the Blanes canyon and adjacent margin, North-western Mediterranean Sea

The bathyal faunal communities of the NW Mediterranean slopes have been studied consistently in the last two decades, with a special focus on population structure, trophic dynamics and benthopelagic coupling of commercial deep-sea decapod crustaceans and fishes (reviewed in Sardà et al. 2004) and associated species (Cartes and Sardà, 1993; Company and Sardà, 1997, 2000; Cartes et al., 2001; Company et al., 2001, 2003, 2004). One of the major topographic features in the North-western Mediterranean slope is the presence of submarine canyons. Canyons play a major role in funnelling energy and organic matter from the shelf to bathyal and abyssal depths (Puig et al., 2000), but the implications of this enhanced organic supply in the deep-sea benthic communities is still mostly unknown. Trophic supply can follow two major pathways – vertical deposition in the water column (Billett et al., 1983; Baldwin et al., 1998; Lampitt et al., 2001) or down-slope advection on the margins (Puig et al., 2001; Bethoux et al., 2002; Canals et al., 2006) – and can be a limiting factor in the deep-sea, being especially important in the oligotrophic Mediterranean Sea (Sardà et al., 2004). Differences in the quantity, quality and timing of organic matter input to the deep seafloor have been used to explain patterns of biomass and abundance in benthic communities (Levin et al., 1994; Gooday & Turley, 1990; Billett et al., 2001; Galéron et al., 2001; Puig et al., 2001; Gage, 2003) as well as other biological process and in particular the existence of seasonal reproduction (Tyler et al., 1994; Company et al., 2004 (MEPS). Reproduction is a highly energetic process tightly linked to food availability and quality.

Positive IgG Western Blot for Borrelia burgdorferi in Colombia

In order to evaluate the presence of specific IgG antibodies to Borrelia burgdorferi in patients with clinical manifestations associated with Lyme borreliosis in Cali, Colombia, 20 serum samples from patients with dermatologic signs, one cerebrospinal fluid (CSF) sample from a patient with chronic neurologic and arthritic manifestations, and twelve serum samples from individuals without clinical signs associated with Lyme borreliosis were analyzed by IgG Western blot. The results were interpreted following the recommendations of the Centers for Diseases Control and Prevention (CDC) for IgG Western blots. Four samples fulfilled the CDC criteria: two serum specimens from patients with morphea (localized scleroderma), the CSF from the patient with neurologic and arthritic manifestations, and one of the controls. Interpretation of positive serology for Lyme disease in non-endemic countries must be cautious. However these results suggest that the putative "Lyme-like" disease may correlate with positivity on Western blots, thus raising the possibility that a spirochete genospecies distinct from B. burgdorferi sensu stricto, or a Borrelia species other than B. burgdorferi sensu lato is the causative agent. Future work will focus on a survey of the local tick and rodent population for evidence of spirochete species that could be incriminated as the etiologic agent.

Sensitivity of a Vacuum Aspiratory Culture Technique for Diagnosis of Localized Cutaneous Leishmaniasis in an Endemic Area of Leishmania (Viannia) braziliensis Transmission

Sixty eight patients with localized cutaneous leishmaniasis from an area with Leishmania (Viannia) braziliensis transmission had cultures performed with a modified Marzochi´s vacuum aspiratory puncture technique to establish sensitivity and contamination rate with this new method. Overall sensitivity of three aspirates was 47.1%; (CI95% 39.4; 59.4) significantly greater than the sensitivity of a single one aspirate. Fungal contamination was observed in 6/204 (2.9%) inoculated culture tubes. We recommend that this useful technique should be adopted as routine for primary isolation of L. (V.) braziliensis from localized cutaneous ulcers.

Population pharmacokinetics and clinical response for artemether-lumefantrine in pregnant and nonpregnant women with uncomplicated Plasmodium falciparum malaria in Tanzania.

Artemether-lumefantrine (AL) is the first-line treatment for uncomplicated malaria in the second and third trimesters of pregnancy. Its efficacy during pregnancy has recently been challenged due to altered pharmacokinetic (PK) properties in this vulnerable group. The aim of this study was to determine the PK profile of AL in pregnant and nonpregnant women and assess their therapeutic outcome. Thirty-three pregnant women and 22 nonpregnant women with malaria were treated with AL (80/480 mg) twice daily for 3 days. All patients provided five venous plasma samples for drug quantification at random times over 7 days. Inter- and intraindividual variability was assessed, and the effects of covariates were quantified using a nonlinear mixed-effects modeling approach (NONMEM). A one-compartment model with first-order absorption and elimination with linear metabolism from drug to metabolite fitted the data best for both arthemether (AM) and lumefantrine (LF) and their metabolites. Pregnancy status and diarrhea showed a significant influence on LF PK. The relative bioavailability of lumefantrine and its metabolism rate into desmethyl-lumefantrine were, respectively, 34% lower and 78% higher in pregnant women than in nonpregnant patients. The overall PCR-uncorrected treatment failure rates were 18% in pregnant women and 5% in nonpregnant women (odds ratio [OR] = 4.04; P value of 0.22). A high median day 7 lumefantrine concentration was significantly associated with adequate clinical and parasitological response (P = 0.03). The observed reduction in the relative bioavailability of lumefantrine in pregnant women may explain the higher treatment failure in this group, mostly due to lower posttreatment prophylaxis. Hence, a modified treatment regimen of malaria in pregnancy should be considered.

The status of the Lutzomyia longipalpis species complex and possible implications for Leishmania transmission

The sand fly Lutzomyia longipalpis sensu latu has been identified as the principal vector of American visceral leishmaniasis, a potentially fatal disease that primarily affects children in several countries of South and Central America. Over the past several years increases have occurred both in the number of reported cases and the population at risk: approximately 1.6 million people reside in highly endemic areas with 16,000 cases reported annually. Several studies have attempted to relate the epidemiology of this disease to variability in Lu. longipalpis that is now recognized to be a complex of at least three sibling species. Morphological variation in this species was first noted by Mangabeira (1969). Since then physiological and biochemical differences have been reported by several investigators. Recent reports in Costa Rica of the presence of Lu. longipalpis in a focus of cutaneous leishmaniasis caused by Leishmania chagasi may be an additional indication of variability in this species. While existing evidence indicates that the morphospecies Lu. longipalpis may represent a complex of sibling species, genetic, epidemiological and ecological distinctions have not been fully resolved. Thus, delimitation of systematic boundaries within the complex and corresponding to geographic distributions and roles in transmission remain unresolved. The purpose of this review is to summarize from the literature observations of polymorphism in this morphospecies and consider what significance this reported variability may have to the epidemiology of visceral leishmaniasis.

The population structure of Trypanosoma cruzi: expanded analysis of 54 strains using eight polymorphic CA-repeat microsatellites

Recently we cloned and sequenced the first eight Trypanosoma cruzi polymorphic microsatellite loci and studied 31 clones and strains to obtain valuable information about the population structure of the parasite. We have now studied 23 further strains, increasing from 11 to 31 the number of strains obtained from patients with chronic Chagas disease. This expanded set of 54 strains and clones analyzed with the eight microsatellites markers confirmed the previously observed diploidy, clonal population organization and very high polymorphism of T. cruzi. Moreover, this new study disclosed two new features of the population genetic structure of T. cruzi. The first was the discovery that, similarly to what we had previously shown for strains isolated from insect vectors, mammals and humans with acute disease, isolates from patients in the chronic phase of Chagas disease could also be multiclonal, albeit at a reduced proportion. Second, when we used parsimony to display the genetic relationship among the clonal lineages in an unrooted Wagner network we observed, like before, a good correlation of the tree topography with the classification in three clusters on the basis of single locus analysis of the ribosomal RNA genes. However, a significant new finding was that now the strains belonging to cluster 2 split in two distant sub-clusters. This observation suggests that the evolutionary history of T. cruzi may be more complex than we previously thought.

Ireland and Northern Ireland's Population Health Observatory (INIsPHO)

Ireland and Northern Ireland's Population Health Observatory (INIsPHO) is housed in  The Institute of Public Health in Ireland (IPH) and is part of the Association of Public Health Observatories (APHO). The Observatory supports those working to improve health and reduce health inequalities by producing, disseminating and supporting the use of relevant health knowledge and strengthening the research and information infrastructure on the island of Ireland.

Preliminary estimates and forecasts of the population prevalence of self reported of hypertension, of ischaemic heart disease and stroke in the Republic of Ireland from 2005 - 2015

Ireland and Northern Ireland’s Population Health Observatory (INIsPHO) recently published estimates of the population prevalence of diabetes in 2005 and forecasts to 2010 and 2015 for the island of Ireland, at the national and sub-national levels. These estimates are based the PBS Model developed by York and Humber Public Health Observatory (YHPHO), Brent NHS Trust and the School of Health and Related Research (ScHARR).The Department of Health and Children (DoHC) has requested additional estimates and forecasts for hypertension.This paper outlines the results from preliminary work from the initial steps towards a more systematic approach to monitoring the prevalence of other chronic diseases on the island.

Developing a population approach to gambling health issues

The Institute of Public Health in Ireland (IPH) has developed this briefing paper to highlight the health impacts connected to gambling and in particular problem gambling.  This paper was developed to give information to Government Departments who are currently reviewing gambling legislation across the island of Ireland.  It draws attention to the impact problem gambling can have on the individual, family and community health and well-being.