Deletion of hepatic small heterodimer partner ameliorates development of nonalcoholic steatohepatitis in mice.

Small heterodimer partner (SHP, Nr0b2) is an orphan nuclear receptor that regulates bile acid, lipid, and glucose metabolism. Shp-/- mice are resistant to diet-induced obesity and hepatic steatosis. In this study, we explored the potential role of SHP in the development of nonalcoholic steatohepatitis (NASH). A 6-month Western diet (WD) regimen was used to induce NASH. Shp deletion protected mice from NASH progression by inhibiting inflammatory and fibrotic genes, oxidative stress, and macrophage infiltration. WD feeding disrupted the ultrastructure of hepatic mitochondria in WT mice but not in Shp-/- mice. In ApoE-/- mice, Shp deletion also effectively ameliorated hepatic inflammation after a 1 week WD regimen without an apparent antisteatotic effect. Moreover, Shp-/- mice resisted fibrogenesis induced by a methionine- and choline-deficient diet. Notably, the observed protection against NASH was recapitulated in liver-specific Shp-/- mice fed either the WD or methionine- and choline-deficient diet. Hepatic cholesterol was consistently reduced in the studied mouse models with Shp deletion. Our data suggest that Shp deficiency ameliorates NASH development likely by modulating hepatic cholesterol metabolism and inflammation.

Microbial products linked to steatohepatitis are reduced by deletion of nuclear hormone receptor SHP in mice.

Deletion of the nuclear hormone receptor small heterodimer partner (Shp) ameliorates the development of obesity and nonalcoholic steatohepatitis (NASH) in mice. Liver-specific SHP plays a significant role in this amelioration. The gut microbiota has been associated with these metabolic disorders, and the interplay between bile acids (BAs) and gut microbiota contributes to various metabolic disorders. Since hepatic SHP is recognized as a critical regulator in BA synthesis, we assessed the involvement of gut microbiota in the antiobesity and anti-NASH phenotype of Shp-/- mice. Shp deletion significantly altered the levels of a few conjugated BAs. Sequencing the 16S rRNA gene in fecal samples collected from separately housed mice revealed apparent dysbiosis in Shp-/- mice. Cohousing Shp-/- mice with WT mice during a Western diet regimen impaired their metabolic improvement and effectively disrupted their distinctive microbiome structure, which became indistinguishable from that of WT mice. While the Western diet challenge significantly increased lipopolysaccharide and phenylacetic acid (PAA) levels in the blood of WT mice, their levels were not increased in Shp-/- mice. PAA was strongly associated with hepatic peroxisome proliferator-activated receptor gamma isoform 2 (Pparg2) activation in mice, which may represent the basis of the molecular mechanism underlying the association of gut bacteria and hepatic steatosis. Shp deletion reshapes the gut microbiota possibly by altering BAs. While lipopolysaccharide and PAA are the major driving forces derived from gut microbiota for NASH development, Shp deletion decreases these signaling molecules via dysbiosis, thereby partially protecting mice from diet-induced metabolic disorders.

Multiplexed Digital Characterization of Misfolded Protein Oligomers via Solid-State Nanopores.

Misfolded protein oligomers are of central importance in both the diagnosis and treatment of Alzheimer's and Parkinson's diseases. However, accurate high-throughput methods to detect and quantify oligomer populations are still needed. We present here a single-molecule approach for the detection and quantification of oligomeric species. The approach is based on the use of solid-state nanopores and multiplexed DNA barcoding to identify and characterize oligomers from multiple samples. We study α-synuclein oligomers in the presence of several small-molecule inhibitors of α-synuclein aggregation as an illustration of the potential applicability of this method to the development of diagnostic and therapeutic methods for Parkinson's disease.

Spatial-temporal distribution of Anopheles larval habitats in Uganda using GIS/remote sensing technologies.

BACKGROUND: Anopheles mosquitoes impose an immense burden on the African population in terms of both human health and comfort. Uganda, in particular, boasts one of the highest malaria transmission rates in the world and its entire population is at risk for infection. Despite the immense burden these mosquitoes pose on the country, very few programmes exist that directly combat the issue at the vector control level and even fewer programmes focus on the vector in its most vulnerable juvenile stages. This study utilizes remote sensing techniques and spatial autocorrelation models to identify and prioritize the most prolific Anopheline larval habitats for control purposes in a rural community in Uganda. METHODS: A community-based mosquito surveillance programme was developed and implemented in Papoli Parish in Eastern Uganda over a 4-month period. Each day, a trained field team sampled the larval habitats of Anopheles mosquitoes within the population-dense areas of the community. Habitats and their productivity were identified and plotted spatially on a daily basis. Daily output was combined and displayed as a weekly habitat time-series. Additional spatial analysis was conducted using the Global and Anselin's Local Moran's I statistic to assess habitat spatial autocorrelation. RESULTS: Spatial models were developed to identify highly significant habitats and dictated the priority of these habitats for larval control purposes. Weekly time-series models identified the locations and productivity of each habitat, while Local Moran's I cluster maps identified statistically significant clusters (Cluster: High) and outliers (High Outlier) that were then interpreted for control priority. Models were stitched together in a temporal format to visually demonstrate the spatial shift of statically significant, high priority habitats over the entire study period. DISCUSSION: The findings show that the spatial outcomes of productive habitats can be made starkly apparent through initial habitat modelling and resulting time-series output. However, mosquito control resources are often limited and it is at this point that the Local Moran's I statistics demonstrates its value. Focusing on habitats identified as Cluster: High and High Outlier outputs allow for the identification of the most influential larval habitats. Utilizing this method for malaria control allows for the optimization of control resources in a real time, community driven, fashion, as well as providing a framework for future control practices.

The use of eculizumab in gemcitabine induced thrombotic microangiopathy.

BACKGROUND: Thrombotic microangiopathy (TMA) secondary to gemcitabine therapy (GiTMA) is a very rare pathology that carries a poor prognosis, with nearly half of the cases progressing to end stage renal disease. GiTMA is most commonly associated with adenocarcinomas, most notably pancreatic cancers. The mainstay of management is withdrawal of the offending drug and supportive care. Plasmapheresis has a limited role and hemodialysis may help in the management of fluid overload secondary to renal failure. Furthermore, a C5 inhibitor, eculizumab, has been successfully used in the treatment of GiTMA. CASE PRESENTATION: A 64-year-old Caucasian female with history of pancreatic adenocarcinoma on gemcitabine chemotherapy presented with signs and symptoms of fluid overload and was found to have abnormal kidney function. Her BP was 195/110 mmHg, serum creatinine 4.48 mg/dl, hemoglobin 8.2 g/dl, platelets 53 × 103/cmm, lactate dehydrogenase 540 IU/L, and was found to have schistocytes on blood film. A diagnosis of TMA secondary to gemcitabine therapy was suspected. Hemodialysis for volume overload and daily plasmapheresis were initiated. After six days of plasmapheresis, renal function did not improve. Further work up revealed ADAMTS 13 activity >15%, low C3, and stool culture and Shiga-toxin PCR were negative. Renal biopsy was consistent with TMA. Gemcitabine was discontinued, but renal function failed to improve and eculizumab therapy was considered due to suspicion of aHUS. Serum creatinine >2.26 mg/dl and a platelet count of >/= 30 × 109/L is highly suggestive of aHUS, while TTP is more likely when creatinine is <2.26 mg/dl and platelet count of <30 × 109/L. She received intravenous eculizumab for eight months, which resulted in significant improvement of renal function. Other markers of hemolysis, namely LDH and bilirubin, also rapidly improved following eculizumab therapy. Plasmapheresis and hemodialysis were discontinued after two and eight weeks of initiation respectively. CONCLUSION: Chemotherapy induced TMA is very rare and requires a high index of clinical suspicion for timely diagnosis. Discontinuation of the offending drug and supportive care is the main stay of treatment; however, eculizumab has been shown to be beneficial in GiTMA. Further research is required to validate this approach.

Discordant circulating fetal DNA and subsequent cytogenetics reveal false negative, placental mosaic, and fetal mosaic cfDNA genotypes.

BACKGROUND: The American College of Obstetrics and Gynecology (ACOG) and Maternal Fetal Medicine (MFM) Societies recommended that abnormal cfDNA fetal results should be confirmed by amniocentesis and karyotyping. Our results demonstrate that normal cfDNA results inconsistent with high-resolution abnormal ultrasounds should be confirmed by karyotyping following a substantial frequency of incorrect cfDNA results. METHODS: Historical review of our ~4,000 signed prenatal karyotypes found ~24% of reported abnormalities would not have been detected by cfDNA. Akron Children's Hospital Cytogenetics Laboratory has completed 28 abnormal cfDNA cases among the 112 amniocenteses karyotyped. RESULTS: Following abnormal cfDNA results our karyotypes confirmed only 60% of the cfDNA results were consistent. Our cases found a normal cfDNA test result followed by a 20 weeks anatomical ultrasound detected a false negative trisomy 18 cfDNA result. One cfDNA result that reported trisomy 21 in the fetus was confirmed by karyotyping which also added an originally undetected balanced reciprocal translocation. Another reported karyotyped case followed by a repeated microarray of pure fetal DNA, together revealed one phenotypically normal newborn with a complex mosaic karyotype substantially decreasing the newborn's eventual reproductive fitness. This second case establishes the importance of karyotyping the placenta and cord or peripheral blood when inconsistent or mosaic results are identified following an abnormal cfDNA result with a normal newborn phenotype without a prenatal karyotype. CONCLUSIONS: These Maternal Fetal Medicine referrals demonstrate that positive NIPT results identify an increased abnormal karyotypic frequency as well as a substantial proportion of discordant fetal results. Our results found: (1) a normal NIPT test result followed by a 20 week anatomical ultrasound detected a false negative trisomy 18 NIPT result, (2) a substantial proportion of abnormal NIPT tests identify chromosomal mosaicism that may or may not be confined to the placenta, (3) follow up karyotyping should be completed on the newborn placenta and peripheral blood when the amniocyte karyotype does not confirm the NIPT reported abnormality in order to identify ongoing risk of developing mosaic symptoms, and (4) karyotyping all high risk fetuses tested by amniocentesis defines the 24% of chromosome abnormalities not currently screened by NIPT.

West Nile virus infection rates and avian serology in east-central Illinois.

Understanding the geographic role of different species of mosquito vectors and vertebrate hosts in West Nile virus (WNV) transmission cycles can facilitate the development and implementation of targeted surveillance and control measures. This study examined the relationship between WNV-antibody rates in birds and mosquito infection rates and bloodfeeding patterns in east-central Illinois. The earliest detection of WNV-RNA by reverse transcription-polymerase chain reaction TaqMan was from Culex restuans; however, amplification typically coincided with an increase in abundance of Cx. pipiens. Trap type influenced annual estimates of infection rates in Culex species, as well as estimation of blood meal source. Bird species with the highest WNV-antibody rates (i.e., Mourning Doves [Zenaida macroura], Northern Cardinals [Cardinalis cardinalis], American Robins [Turdus migratorius], and House Sparrows [Passer domesticus]) were also the common species found in Culex blood meals. Although antibody rates were not directly proportional to estimated avian abundance, the apparent availability of mammal species did influence proportion of mammal to bird blood meals. Antibody prevalence in the American Robin was lower than expected based on the strong attraction of Culex to American Robins for blood meals. Age-related differences in serology were evident, antibody rates increased in older groups of robins and sparrows, whereas 1st-year hatch and older adults of Mourning Doves and Northern Cardinals had equally high rates of antibody-positive serum samples. The vector and host interactions observed in east-central Illinois (Champaign County), an urban area surrounded by agriculture, are compared to studies in the densely population areas of southern Cook County.

Quasi-Likelihood Techniques in a Logistic Regression Equation for Identifying Simulium damnosum s.l. Larval Habitats Intra-cluster Covariates in Togo.

The standard methods for regression analyses of clustered riverine larval habitat data of Simulium damnosum s.l. a major black-fly vector of Onchoceriasis, postulate models relating observational ecological-sampled parameter estimators to prolific habitats without accounting for residual intra-cluster error correlation effects. Generally, this correlation comes from two sources: (1) the design of the random effects and their assumed covariance from the multiple levels within the regression model; and, (2) the correlation structure of the residuals. Unfortunately, inconspicuous errors in residual intra-cluster correlation estimates can overstate precision in forecasted S.damnosum s.l. riverine larval habitat explanatory attributes regardless how they are treated (e.g., independent, autoregressive, Toeplitz, etc). In this research, the geographical locations for multiple riverine-based S. damnosum s.l. larval ecosystem habitats sampled from 2 pre-established epidemiological sites in Togo were identified and recorded from July 2009 to June 2010. Initially the data was aggregated into proc genmod. An agglomerative hierarchical residual cluster-based analysis was then performed. The sampled clustered study site data was then analyzed for statistical correlations using Monthly Biting Rates (MBR). Euclidean distance measurements and terrain-related geomorphological statistics were then generated in ArcGIS. A digital overlay was then performed also in ArcGIS using the georeferenced ground coordinates of high and low density clusters stratified by Annual Biting Rates (ABR). This data was overlain onto multitemporal sub-meter pixel resolution satellite data (i.e., QuickBird 0.61m wavbands ). Orthogonal spatial filter eigenvectors were then generated in SAS/GIS. Univariate and non-linear regression-based models (i.e., Logistic, Poisson and Negative Binomial) were also employed to determine probability distributions and to identify statistically significant parameter estimators from the sampled data. Thereafter, Durbin-Watson test statistics were used to test the null hypothesis that the regression residuals were not autocorrelated against the alternative that the residuals followed an autoregressive process in AUTOREG. Bayesian uncertainty matrices were also constructed employing normal priors for each of the sampled estimators in PROC MCMC. The residuals revealed both spatially structured and unstructured error effects in the high and low ABR-stratified clusters. The analyses also revealed that the estimators, levels of turbidity and presence of rocks were statistically significant for the high-ABR-stratified clusters, while the estimators distance between habitats and floating vegetation were important for the low-ABR-stratified cluster. Varying and constant coefficient regression models, ABR- stratified GIS-generated clusters, sub-meter resolution satellite imagery, a robust residual intra-cluster diagnostic test, MBR-based histograms, eigendecomposition spatial filter algorithms and Bayesian matrices can enable accurate autoregressive estimation of latent uncertainity affects and other residual error probabilities (i.e., heteroskedasticity) for testing correlations between georeferenced S. damnosum s.l. riverine larval habitat estimators. The asymptotic distribution of the resulting residual adjusted intra-cluster predictor error autocovariate coefficients can thereafter be established while estimates of the asymptotic variance can lead to the construction of approximate confidence intervals for accurately targeting productive S. damnosum s.l habitats based on spatiotemporal field-sampled count data.

Left ventricular venting in veno-arterial extracorporeal membrane oxygenation: A computer simulation study.

INTRODUCTION: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is the fastest way to restore circulation in refractory cardiogenic shock, however it cannot unload the failing left ventricle. There is a lack of consensus regarding optimal approach to left ventricular venting in V-A ECMO patients with severely depressed or absent left ventricular function. METHODS: A computer model was developed in Matlab Simulink R20016b (MathWorks, Inc., Natick, MA, USA) to analyze different venting options as well as atrial septostomy in the setting of cardiogenic shock and V-A ECMO. RESULTS: The model has shown an inverse linear relationship between left atrial pressure and either vent, Impella or atrial septum defect flow rate. The minimum vent flow required to prevent pulmonary edema in complete loss of left ventricular function needed to be higher than the bronchial blood flow. Atrial septostomy restored normal pulmonary blood flow with low left atrial pressure but induced stasis in the left ventricle. Venting the pulmonary artery induced stasis in the entire pulmonary circulation as well as left atrium and left ventricle. Venting the left ventricle directly with a cannula or Impella device avoided blood stasis. CONCLUSION: Our data suggest that reduction of left atrial pressure is linearly related to the vent, Impella or atrial septal defect flow rate. The preferred vent location is the left ventricle as it avoids stasis in the pulmonary circulation and cardiac chambers.

Bile acid conjugation deficiency causes hypercholanemia, hyperphagia, islet dysfunction, and gut dysbiosis in mice.

Bile acid-CoA: amino acid N-acyltransferase (BAAT) catalyzes bile acid conjugation, the last step in bile acid synthesis. BAAT gene mutation in humans results in hypercholanemia, growth retardation, and fat-soluble vitamin insufficiency. The current study investigated the physiological function of BAAT in bile acid and lipid metabolism using Baat-/- mice. The bile acid composition and hepatic gene expression were analyzed in 10-week-old Baat-/- mice. They were also challenged with a westernized diet (WD) for additional 15 weeks to assess the role of BAAT in bile acid, lipid, and glucose metabolism. Comprehensive lab animal monitoring system and cecal 16S ribosomal RNA gene sequencing were used to evaluate the energy metabolism and microbiome structure of the mice, respectively. In Baat-/- mice, hepatic bile acids were mostly unconjugated and their levels were significantly increased compared with wild-type mice. Bile acid polyhydroxylation was markedly up-regulated to detoxify unconjugated bile acid accumulated in Baat-/- mice. Although the level of serum marker of bile acid synthesis, 7α-hydroxy-4-cholesten-3-one, was higher in Baat-/- mice, their bile acid pool size was smaller. When fed a WD, the Baat-/- mice showed a compromised body weight gain and impaired insulin secretion. The gut microbiome of Baat-/- mice showed a low level of sulfidogenic bacteria Bilophila. Conclusion: Mouse BAAT is the major taurine-conjugating enzyme. Its deletion protected the animals from diet-induced obesity, but caused glucose intolerance. The gut microbiome of the Baat-/- mice was altered to accommodate the unconjugated bile acid pool.

Waldenström's macroglobulinemia and nephrotic syndrome with membranous nephropathy.

Renal complications of Waldenström's macroglobulinemia (WM) are rarely observed. Nephrotic syndrome in association with WM has most often been secondary to amyloidosis. This article reports a case of WM with nephrotic syndrome as a result of membranous nephropathy with immunoglobulin M (IgM) deposition. A 44-year-old male diagnosed with WM 4 years previously, presented with heavy proteinuria (7.8 g/24 h). Kidney biopsy revealed expanded mesangium, thickened capillary loops and epimembranous spikes, with no significant interstitial inflammation or thickened tubular basement membranes. Immunofluorescence examination demonstrated strong granular staining of IgM and λ chains, with weaker C3 and C1q staining. Electron microscopy showed many subepithelial dense deposits, and fewer large subendothelial dense deposits. Treatment was directed at the patient's WM with maintenance rituximab and fludarabine. Subsequently, decreases were seen in both the patient's serum IgM and serum viscosity. With therapy for WM and the addition of an angiotensin receptor blocker, the patient's proteinuria also improved, from 7.8 g to 4.8 g/24 h. The patient continued to follow up with his hematologist and in 2009 creatinine was 1 mg/dl (76.26 ?mol/l), with a 24 h urine protein excretion of 0.159 g.

Anopheles larval abundance and diversity in three rice agro-village complexes Mwea irrigation scheme, central Kenya.

BACKGROUND: The diversity and abundance of Anopheles larvae has significant influence on the resulting adult mosquito population and hence the dynamics of malaria transmission. Studies were conducted to examine larval habitat dynamics and ecological factors affecting survivorship of aquatic stages of malaria vectors in three agro-ecological settings in Mwea, Kenya. METHODS: Three villages were selected based on rice husbandry and water management practices. Aquatic habitats in the 3 villages representing planned rice cultivation (Mbui Njeru), unplanned rice cultivation (Kiamachiri) and non-irrigated (Murinduko) agro-ecosystems were sampled every 2 weeks to generate stage-specific estimates of mosquito larval densities, relative abundance and diversity. Records of distance to the nearest homestead, vegetation coverage, surface debris, turbidity, habitat stability, habitat type, rice growth stage, number of rice tillers and percent Azolla cover were taken for each habitat. RESULTS: Captures of early, late instars and pupae accounted for 78.2%, 10.9% and 10.8% of the total Anopheles immatures sampled (n = 29,252), respectively. There were significant differences in larval abundance between 3 agro-ecosystems. The village with 'planned' rice cultivation had relatively lower Anopheles larval densities compared to the villages where 'unplanned' or non-irrigated. Similarly, species composition and richness was higher in the two villages with either 'unplanned' or limited rice cultivation, an indication of the importance of land use patterns on diversity of larval habitat types. Rice fields and associated canals were the most productive habitat types while water pools and puddles were important for short periods during the rainy season. Multiple logistic regression analysis showed that presence of other invertebrates, percentage Azolla cover, distance to nearest homestead, depth and water turbidity were the best predictors for Anopheles mosquito larval abundance. CONCLUSION: These results suggest that agricultural practices have significant influence on mosquito species diversity and abundance and that certain habitat characteristics favor production of malaria vectors. These factors should be considered when implementing larval control strategies which should be targeted based on habitat productivity and water management.

Interspecies predation between Anopheles gambiae s.s. and Culex quinquefasciatus larvae.

Interaction of aquatic stages of coexisting mosquito species may have significant influence on resulting adult mosquito populations. We used two coexisting species, Anopheles gambiae s.s. and Culex quinquefasciatus to investigate whether third instars of one species consumed first instars of the other. First instars of one species were readily consumed by a third instar of the other species irrespective food quantity. DNA of Cx. quinquefasciatus was detected in the eight An. gambiae s.s. third instars presumed to have consumed at least one Cx. quinquefasciatus first instar. Likewise, DNA of An. gambiae s.s. was detected in five of eight Cx. quinquefasciatus third instars presumed to have consumed at least one An. gambiae s.s. first instar. A small number of dead first instars was found in the controls indicating that some larvae in the treatment group may have been consumed after they had died. These findings suggest that intraguild predation between the two species may be common in nature and that it is a facultative process that is not induced by food shortage. The findings further suggest that polymerase chain reaction could be a useful technique in the study of this phenomenon in natural habitats.

Population genetic structure of Anopheles arabiensis (Diptera: Culicidae) in a rice growing area of central Kenya.

Studies were conducted to examine the population genetic structure of Anopheles arabiensis (Patton) in Mwea Rice Irrigation Scheme and surrounding areas in Central Kenya, under different agricultural systems. This study was motivated by observed differences in malaria transmission indices of An. arabiensis within the scheme compared with adjacent nonirrigated areas. Agricultural practices can modify local microclimate and influence the number and diversity of larval habitats and in so doing may occasion subpopulation differentiation. Thirty samples from each of the three study sites were genotyped at eight microsatellite loci. Seven microsatellite loci showed high polymorphism but revealed no genetic differentiation (FST = 0.006, P = 0.312) and high gene flow (Nm = 29-101) among the three populations. Genetic bottleneck analysis showed no indication of excess heterozygosity in any of the populations. There was high frequency of rare alleles, suggesting that An. arabiensis in the study area has a high potential of responding to selective pressures from environmental changes and vector control efforts. These findings imply that An. arabiensis in the study area occurs as a single, continuous panmictic population with great ability to adapt to human-imposed selective pressures.

Developing GIS-based eastern equine encephalitis vector-host models in Tuskegee, Alabama.

BACKGROUND: A site near Tuskegee, Alabama was examined for vector-host activities of eastern equine encephalomyelitis virus (EEEV). Land cover maps of the study site were created in ArcInfo 9.2 from QuickBird data encompassing visible and near-infrared (NIR) band information (0.45 to 0.72 microm) acquired July 15, 2008. Georeferenced mosquito and bird sampling sites, and their associated land cover attributes from the study site, were overlaid onto the satellite data. SAS 9.1.4 was used to explore univariate statistics and to generate regression models using the field and remote-sampled mosquito and bird data. Regression models indicated that Culex erracticus and Northern Cardinals were the most abundant mosquito and bird species, respectively. Spatial linear prediction models were then generated in Geostatistical Analyst Extension of ArcGIS 9.2. Additionally, a model of the study site was generated, based on a Digital Elevation Model (DEM), using ArcScene extension of ArcGIS 9.2. RESULTS: For total mosquito count data, a first-order trend ordinary kriging process was fitted to the semivariogram at a partial sill of 5.041 km, nugget of 6.325 km, lag size of 7.076 km, and range of 31.43 km, using 12 lags. For total adult Cx. erracticus count, a first-order trend ordinary kriging process was fitted to the semivariogram at a partial sill of 5.764 km, nugget of 6.114 km, lag size of 7.472 km, and range of 32.62 km, using 12 lags. For the total bird count data, a first-order trend ordinary kriging process was fitted to the semivariogram at a partial sill of 4.998 km, nugget of 5.413 km, lag size of 7.549 km and range of 35.27 km, using 12 lags. For the Northern Cardinal count data, a first-order trend ordinary kriging process was fitted to the semivariogram at a partial sill of 6.387 km, nugget of 5.935 km, lag size of 8.549 km and a range of 41.38 km, using 12 lags. Results of the DEM analyses indicated a statistically significant inverse linear relationship between total sampled mosquito data and elevation (R2 = -.4262; p < .0001), with a standard deviation (SD) of 10.46, and total sampled bird data and elevation (R2 = -.5111; p < .0001), with a SD of 22.97. DEM statistics also indicated a significant inverse linear relationship between total sampled Cx. erracticus data and elevation (R2 = -.4711; p < .0001), with a SD of 11.16, and the total sampled Northern Cardinal data and elevation (R2 = -.5831; p < .0001), SD of 11.42. CONCLUSION: These data demonstrate that GIS/remote sensing models and spatial statistics can capture space-varying functional relationships between field-sampled mosquito and bird parameters for determining risk for EEEV transmission.

Clinical, serological and DNA testing in Bengo Province, Angola further reveals low filarial endemicity and opportunities for disease elimination.

The prevalence of Loa loa, Onchocerca volvulus and Wuchereria bancrofti infections in an under-surveyed area of Bengo Province, Angola, was determined by surveying 22 communities with a combination of clinical, serological and DNA diagnostics. Additional information was collected on participants' duration of residency, access to mass drug administration, knowledge of insect vectors and use of bednets. A total of 1616 individuals (38.1% male: 61.9% female), with an average age of 43 years, were examined. For L. loa, 6.2% (n = 100/16616) individuals were found to have eyeworm, based on the rapid assessment procedure for loiasis (RAPLOA) surveys, and 11.5% (n =178/1543) based on nested PCR analyses of venous blood. L. loa prevalences in long-term residents (>10 years) and older individuals (>60 years) were significantly higher, and older men with eyeworm were better informed about Chrysops vectors. For O. volvulus, 4.7% (n = 74/1567) individuals were found to be positive by enzyme-linked immunosorbent assay (Ov 16 ELISA), with only three individuals reporting to have ever taken ivermectin. For W. bancrofti, no infections were found using the antigen-based immunochromatographic test (ICT) and real-time PCR analysis; however, 27 individuals presented with lymphatic filariasis (LF) related clinical conditions (lymphoedema = 11, hydrocoele = 14, both = 2). Just under half (45.5%) of the participants owned a bednet, with the majority (71.1%) sleeping under it the night before. Our approach of using combination diagnostics reveals the age-prevalence of loiasis alongside low endemicity of onchocerciasis and LF. Future research foci should be on identifying opportunities for more cost-effective ways to eliminate onchocerciasis and to develop innovative surveillance modalities for clinical LF for individual disease management and disability prevention.

Predicting the impact of insecticide-treated bed nets on malaria transmission: the devil is in the detail.

BACKGROUND: Insecticide-treated bed nets (ITNs), including long-lasting insecticidal nets (LLINs), play a primary role in global campaigns to roll back malaria in tropical Africa. Effectiveness of treated nets depends on direct impacts on individual mosquitoes including killing and excite-repellency, which vary considerably among vector species due to variations in host-seeking behaviours. While monitoring and evaluation programmes of ITNs have focuses on morbidity and all-cause mortality in humans, local entomological context receives little attention. Without knowing the dynamics of local vector species and their responses to treated nets, it is difficult to predict clinical outcomes when ITN applications are scaled up across African continent. Sound model frameworks incorporating intricate interactions between mosquitoes and treated nets are needed to develop the predictive capacity for scale-up applications of ITNs. METHODS: An established agent-based model was extended to incorporate the direct outcomes, e.g. killing and avoidance, of individual mosquitoes exposing to ITNs in a hypothetical village setting with 50 houses and 90 aquatic habitats. Individual mosquitoes were tracked throughout the life cycle across the landscape. Four levels of coverage, i.e. 40, 60, 80 and 100%, were applied at the household level with treated houses having only one bed net. By using Latin hypercube sampling scheme, parameters governing killing, diverting and personal protection of net users were evaluated for their relative roles in containing mosquito populations, entomological inoculation rates (EIRs) and malaria incidence. RESULTS: There were substantial gaps in coverage between households and individual persons, and 100% household coverage resulted in circa 50% coverage of the population. The results show that applications of ITNs could give rise to varying impacts on population-level metrics depending on values of parameters governing interactions of mosquitoes and treated nets at the individual level. The most significant factor in determining effectiveness was killing capability of treated nets. Strong excito-repellent effect of impregnated nets might lead to higher risk exposure to non-bed net users. CONCLUSION: With variabilities of vector mosquitoes in host-seeking behaviours and the responses to treated nets, it is anticipated that scale-up applications of INTs might produce varying degrees of success dependent on local entomological and epidemiological contexts. This study highlights that increased ITN coverage led to significant reduction in risk exposure and malaria incidence only when treated nets yielded high killing effects. It is necessary to test efficacy of treated nets on local dominant vector mosquitoes, at least in laboratory, for monitoring and evaluation of ITN programmes.

Patterns of Plasmodium vivax and Plasmodium falciparum malaria underscore importance of data collection from private health care facilities in India.

BACKGROUND: This study describes patterns of falciparum and vivax malaria in a private comprehensive-care, multi-specialty hospital in New Delhi from July 2006 to July 2008. METHODS: Malarial morbidity by Plasmodium species (Plasmodium falciparum, Plasmodium vivax, or Plasmodium sp.) was confirmed using microscopy and antigen tests. The influence of seasonal factors and selected patient demographics on morbidity was evaluated. The proportions of malaria cases caused by P. falciparum at the private facility were compared to data from India's National Vector Borne Disease Control Programme (NVBDCP) during the same period for the Delhi region. RESULTS: In New Delhi, P. faciparum was the dominant cause of cases requiring treatment in the private hospital during the period examined. The national data reported a smaller proportion of malaria cases caused by P. falciparum in the national capital region than was observed in a private facility within the region. Plasmodium vivax also caused a large proportion of the cases presenting clinically at the private hospital during the summer and monsoon seasons. CONCLUSION: The proportion of P. falciparum malaria cases tends to be greatest during the post-monsoon season while the proportion of P. vivax malaria cases tends to be greatest in the monsoon season. Private hospital data demonstrate an under-reporting of malaria case incidences in the data from India's national surveillance programme during the same period for the national capital region.

A heteroskedastic error covariance matrix estimator using a first-order conditional autoregressive Markov simulation for deriving asympotical efficient estimates from ecological sampled Anopheles arabiensis aquatic habitat covariates.

BACKGROUND: Autoregressive regression coefficients for Anopheles arabiensis aquatic habitat models are usually assessed using global error techniques and are reported as error covariance matrices. A global statistic, however, will summarize error estimates from multiple habitat locations. This makes it difficult to identify where there are clusters of An. arabiensis aquatic habitats of acceptable prediction. It is therefore useful to conduct some form of spatial error analysis to detect clusters of An. arabiensis aquatic habitats based on uncertainty residuals from individual sampled habitats. In this research, a method of error estimation for spatial simulation models was demonstrated using autocorrelation indices and eigenfunction spatial filters to distinguish among the effects of parameter uncertainty on a stochastic simulation of ecological sampled Anopheles aquatic habitat covariates. A test for diagnostic checking error residuals in an An. arabiensis aquatic habitat model may enable intervention efforts targeting productive habitats clusters, based on larval/pupal productivity, by using the asymptotic distribution of parameter estimates from a residual autocovariance matrix. The models considered in this research extends a normal regression analysis previously considered in the literature. METHODS: Field and remote-sampled data were collected during July 2006 to December 2007 in Karima rice-village complex in Mwea, Kenya. SAS 9.1.4 was used to explore univariate statistics, correlations, distributions, and to generate global autocorrelation statistics from the ecological sampled datasets. A local autocorrelation index was also generated using spatial covariance parameters (i.e., Moran's Indices) in a SAS/GIS database. The Moran's statistic was decomposed into orthogonal and uncorrelated synthetic map pattern components using a Poisson model with a gamma-distributed mean (i.e. negative binomial regression). The eigenfunction values from the spatial configuration matrices were then used to define expectations for prior distributions using a Markov chain Monte Carlo (MCMC) algorithm. A set of posterior means were defined in WinBUGS 1.4.3. After the model had converged, samples from the conditional distributions were used to summarize the posterior distribution of the parameters. Thereafter, a spatial residual trend analyses was used to evaluate variance uncertainty propagation in the model using an autocovariance error matrix. RESULTS: By specifying coefficient estimates in a Bayesian framework, the covariate number of tillers was found to be a significant predictor, positively associated with An. arabiensis aquatic habitats. The spatial filter models accounted for approximately 19% redundant locational information in the ecological sampled An. arabiensis aquatic habitat data. In the residual error estimation model there was significant positive autocorrelation (i.e., clustering of habitats in geographic space) based on log-transformed larval/pupal data and the sampled covariate depth of habitat. CONCLUSION: An autocorrelation error covariance matrix and a spatial filter analyses can prioritize mosquito control strategies by providing a computationally attractive and feasible description of variance uncertainty estimates for correctly identifying clusters of prolific An. arabiensis aquatic habitats based on larval/pupal productivity.

Spatial distribution, blood feeding pattern, and role of Anopheles funestus complex in malaria transmission in central Kenya.

Studies were conducted to determine the role of sibling species of Anopheles funestus complex in malaria transmission in three agro-ecosystems in central Kenya. Mosquitoes were sampled indoors and outdoors, and rDNA PCR was successfully used to identify 340 specimens. Anopheles parensis (91.8%), A. funestus (6.8%), and Anopheles leesoni (1.5%) were the three sibling species identified. A. parensis was the dominant species at all study sites, while 22 of 23 A. funestus were collected in the non-irrigated study site. None of the 362 specimens tested was positive for Plasmodium falciparum circumsporozoite proteins by enzyme-linked immunosorbent assay. The most common blood-meal sources (mixed blood meals included) for A. parensis were goat (54.0%), human (47.6%), and bovine (39.7%), while the few A. funestus s.s. samples had fed mostly on humans. The human blood index (HBI) for A. parensis (mixed blood meals included) in the non-irrigated agro-ecosystem was 0.93 and significantly higher than 0.33 in planned rice agro-ecosystem. The few samples of A. funestus s.s. and A. funestus s.l. also showed a trend of higher HBI in the non-irrigated agro-ecosystem. We conclude that agricultural practices have significant influence on distribution and blood feeding behavior of A. funestus complex. Although none of the species was implicated with malaria transmission, these results may partly explain why non-irrigated agro-ecosystems are associated with higher risk of malaria transmission by this species compared to irrigated agro-ecosystems.