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Entamoeba gingivalis has been associated with periodontal diseases. Baseline data from the background population, which could help delimit the role of the parasite in health and disease, remain limited. To describe epidemiological features, genetic diversity, and associations with oral microbiome signatures of E. gingivalis colonisation in Tanzanians with non-oral/non-dental diseases. DNAs from 92 oral washings from 52 participants were subject to metabarcoding of ribosomal genes. DNA sequences were identified to genus level and submitted to oral microbiota diversity analyses. Sixteen (31%) of the 52 study participants were E. gingivalis-positive, with no difference in positivity rate according to gender or age. Only one subtype (ST1) was found. Individuals testing positive for E. gingivalis had higher oral microbiota alpha diversity than those testing negative (P = 0.03). Eight of the top-ten most common bacterial genera were shared between the two groups (Alloprevotella, Fusobacterium, Gemella, Haemophilus, Neisseria, Porphyromonas, Prevotella, Streptococcus, and Veillonella). Meanwhile, E. gingivalis carriers and non-carriers were more likely to have Aggregatibacter and Rothia, respectively, among the top-ten most common genera. About one third of the cohort carried E. gingivalis ST1, and carriers had higher oral microbiome diversity and were more predominantly colonized by Aggregatibacter. [ABSTRACT FROM AUTHOR]

1. Ascarids (Ascaridia galli and Heterakis spp.) are highly prevalent in free-range laying hens. Ascarid eggs survive for long periods in soil, and one preventive measure is to add litter material to areas close to the henhouse. In this study, recovery rates of ascarid eggs from three common litter materials, namely pea gravel, beech (Fagus sylvatica) and spruce (Picea abies) wood chips were compared to recovery rates from soil. 2. Materials were mixed with faeces containing 1,408 ascarid eggs per g of faeces, placed in plastic fruit boxes and exposed to natural weather conditions in a randomised block design with six replicates per treatment. 3. Numbers of ascarid eggs were quantified at 28 time points over 3.5 years. Ascarid eggs were recovered for over three years from all materials and completely disappeared during the fourth winter of exposure. Time needed to get to a 50% reduction in ascarid eggs did not differ between litter materials and soil (242 to 269 days). A 99% reduction was reached significantly (P < 0.001) earlier in pea gravel (548 days) than in the three other materials, and earlier in the two wood chips (day 682 for beech, day 692 for spruce, P < 0.05) than in soil (1,277 days). 4. Accumulation of ascarid eggs in the area close to the henhouse can be reduced by any of the tested litter materials compared to bare soil. Adding litter to this area is highly recommended for free-range layer farmers in order to reduce numbers of infective ascarid eggs. [ABSTRACT FROM AUTHOR]

1. There is huge emphasis in veterinary and agricultural science in understanding the basics of processes and exploiting them for benefits to the economy and human and animal welfare. It is always valuable to be able to step back from existing or favourite hypotheses and paradigms to look at an area of work or problem and see whether a different approach might be productive particularly by drawing parallels with other sometimes unrelated problems. 2. This approach has been used to explore (i) the use of live, attenuated Salmonella vaccines to generate a new form of competitive exclusion, (ii) gene expression technology for the design of improved inactivated vaccines (iii) use of cytokine therapy to reduce persistent carriage by Salmonella, (iv) using bacteriophages to reduce carcass contamination by food-borne pathogens and reduce carriage of antibiotic resistance plasmids. 3. The potential for extending virus therapy to parasite infections is also discussed. [ABSTRACT FROM AUTHOR]

When the power of different nonparametric tests is evaluated by simulation, the alternative hypothesis should be carefully designed to ensure validity of the results in the specific research field. In the article, we propose a probit-based progressive shift alternative that is more realistic than the simple shift alternative for skewed non-negative data that occur in many research areas. Our motivation comes from parasitology. The progressive shift alternative is used to compare the power of six location-scale tests and seven commonly used location tests for several skewed theoretical and empirical parasite distributions. It is shown that location-scale tests are more powerful than location tests. Programs for applying the methods studied in the article are freely available for download. [ABSTRACT FROM AUTHOR]

The objective of this research was to assess the effectiveness of dietary supplementation with oils extracted from Origanum vulgare (Lamiaceae) and Citrus spp. (Citraceae) against coccidia and to determine the impact on lamb growth in an indoor housing system. A total of 222 ewes and 276 lambs of the Polish Lowland Sheep breed maintained indoors under the same environmental conditions were included in the study. Four-month pregnant ewes were divided into three treatment groups following parasitological evaluation. Experimental diets were supplemented with containing vegetal extracts of O. vulgare and Citrus spp. During the study, parasitological analyses and assessments of lamb growth were conducted. In vivo evaluation of lamb muscularity and fatness was performed at 100 days of age. The inclusion of the preparation containing the essential oil blend of O. vulgare and Citrus spp. in the diet of sheep resulted in decreases in both the intensity and prevalence of coccidian infection within the flock as well had influence increases in lamb growth. Therefore, this dietary supplement may contribute to the improved profitability of sheep farming through increased production efficiency and the production of higher-quality meat. [ABSTRACT FROM AUTHOR]

Context: Cetuximab is an epidermal growth factor receptor inhibitor. It is frequently used in the treatment of solid tumors. However, it has a high potential to cause acne-like rash. Demodex mites, which are known to increase in number in immunosuppressive circumstances, are closely related to the acneiform lesions. Objective: The aim of this study is to evaluate the presence of demodex mites in acne-like rash that appears under the treatment of Cetuximab. Methods: We reviewed the medical records of patients who applied to our clinic with cetuximab induced papulopustular rashes between November 2014 and March 2016. Demodex sampling was performed by standardized skin surface biopsy (SSSB) in a total of 11 patients (eight males and three females). Infestation was defined as at least 5 living parasites/cm2of skin. Results: Upon the SSSB examination in 10 out of the 11 patients, no demodex mites were detected. Demodex mites were found in only one of the patients. This patient, in whom two dead Demodex folliculorums were found through facial sampling, was also regarded as negative since his demodex density was under the threshold limit value. Conclusion: In this study, it has been concluded that acne-like rash that develops under the treatment of cetuximab is not related to the presence of demodex mites. Papulopustular eruptions that develop under cetuximab treatment should not be directly correlated with the presence of demodex; first SSSB and demodex presence should be evaluated. [ABSTRACT FROM AUTHOR]

1. Selected health and welfare variables of laying hens from 79 flocks kept in alternative husbandry systems were assessed at the end of lay. 2. Investigations were carried out on 100 hens per flock at the slaughter line and recorded as part of a novel scoring system. In addition, post-mortem investigations as well as parasitological examinations were conducted on 10 birds from each flock. 3. Birds with access to free range had better plumage than birds kept in barn systems. Housing in aviaries was associated with a higher prevalence of foot pad lesions and keel bone deformations. In addition, poorer plumage, more and worse skin and foot pad lesions were documented in hens slaughtered during the winter months. 4. Oophoritis and/or salpingitis were the most prevalent pathomorphological changes observed. Intestinal parasites, especiallyHeterakis gallinarumandAscaridia galli, were frequent. Hens kept indoors had fewer nematoda and cestoda than those from conventional and organic free range. 5. The slaughterhouse protocol allowed direct comparison of variables between flocks and specific problems to be identified in particular flocks. The results could be used to initiate detailed investigations into problematic issues on selected farms. [ABSTRACT FROM AUTHOR]

Microbiology, developed in the decades before the First World War, encouraged a particular vision of disease and human social relationships. Some of the consequences of that can be seen in the way in which the Central Powers engaged with Romania during combat operations and during the occupation. Much as with colonial approaches to disease in tropical Africa, parasitology encouraged Germans to focus on bacteria and vectors of disease rather than on social relations or indigenous humans. As a consequence, medical care was segregated: it focused on protecting occupiers, and encouraged Germans to construct Romania and Romanians as colonial. [ABSTRACT FROM PUBLISHER]

Lake Liambezi forms the periodic connection between the upper Zambezi, Kwando and Okavango rivers. A full parasitological assessment was conducted on 86 fish, representing 14 species in six families sampled in August 2011. Parasite diversity was low and dominated by species with complex life cycles involving intermediate hosts. Most prevalent were larval nematodes (Contracaecumsp.) infecting 12 andTrypanasomasp. infecting nine of the 14 host species. The intra-erythrocytic parasiteBabesiosoma mariaewas found in the blood ofCoptodon rendalliandOreochromis andersoniiwith prevalence of 50% and 60%, respectively. The host-specific monogeneanAnnulotrema hepsetiwas recorded only fromH. cuvieriwith a prevalence of 100%. Notable absences were the copepod and branchiuran parasites that have direct lifecycles and usually occur in high prevalence and abundance in the region. Because parasites with direct life cycles can only be transported into the lake on the host fish, their absence suggests limited immigration of infected fishes into the lake. This suggests that internal recruitment dominates over immigration in the fish population dynamics in Lake Liambezi. [ABSTRACT FROM PUBLISHER]

Host characteristics, including sex, age and size, can influence parasite intensity.Ceroglossus buqueti(Laporte, 1834) and its mites were studied to determine the influence of size and sex on parasite abundance, and check for any preference for a particular region of the body. One hundred and fifty-sevenC. buquetiindividuals (64 males and 93 females), captured in the summer of 2007 in Villarrica National Park, Chile, were examined. AllC. buquetiwere parasitized byHexathrombium c.f marittae(Haitlinger, 1994). Male beetles were significantly smaller than female beetles, but parasite abundance in males and females was the same. Likewise, there was no relationship between host body size and parasite abundance. The body distribution analysis showed thatH. c.f. marittaepreferred to attach to the head, ventral thorax and ventral abdomen. We speculate that these preferred regions provide more protection and space for the parasite to colonize the host. [ABSTRACT FROM PUBLISHER]

Parasitic diseases of the central nervous system are associated with high mortality and morbidity, especially in resource-limited settings. The burden of these diseases is amplified as survivors are often left with neurologic sequelae affecting mobility, sensory organs, and cognitive functions, as well as seizures/epilepsy. These diseases inflict suffering by causing lifelong disabilities, reducing economic productivity, and causing social stigma. The complexity of parasitic life cycles and geographic specificities, as well as overlapping clinical manifestations in the host reflecting the diverse pathogenesis of parasites, can present diagnostic challenges. We herein provide an overview of these parasitic diseases and summarize clinical aspects, diagnosis, therapeutic strategies and recent milestones, and aspects related to prevention and control. [ABSTRACT FROM PUBLISHER]

Cratoxylum formosumDyer has been used in Southeast Asian countries both for food and folk medicine. In this study, the leaf extracts ofC. formosumwere evaluated for anticancer effects on human cholangiocarcinoma (CCA) KKU-M156 cells. The results showed that the plant extracts possessed potent cytotoxicity against CCA cells. The cytotoxic activity was associated with an induction of cell apoptosis. Moreover, the colony forming ability of CCA cells was also inhibited byC. formosumextracts. Consistent with growth inhibitory effects, the plant extracts induced cell cycle arrest at the G2/M phase and downregulated cyclin A and Cdc25A protein expression. The extracts potently suppressed the migration and invasion properties of CCA cells. The effects were associated with the suppression of NF-κB and STAT3 nuclear translocation and transcriptional activity, and downregulation of genes involving in cancer progression and metastasis. Furthermore, the possible bioactive compounds in the extracts were analyzed by HPLC. Taken together, the potent anticancer activity ofC. formosumagainst CCA indicates the plant promising use for CCA prevention and therapy. [ABSTRACT FROM PUBLISHER]

The paper presents an overview of the history of aquatic parasitology of freshwater fish in southern Africa. Aquatic parasitology has become a very popular field of specialisation in South Africa and is currently practised by a number of individual research groups at different universities. So far most research deals with parasites of wild fish rather than pathogens of aquaculture. It is written as a narrative and summarises the aquatic parasitology research mostly on fish parasites carried out at the universities of Cape Town, Free State, Johannesburg, Limpopo, Pretoria, North West and Sefako Makgatho Health Sciences. It is not intended to be a review in the classical way because it deals with parasites ranging from Protozoa to Arthropoda. [ABSTRACT FROM PUBLISHER]

Genetic parameters were determined for the worm burden of the most common gastro-intestinal nematodes in two chicken genotypes after being exposed to free-range farming conditions for a laying period.Seventeen-week-old hens of 2 brown genotypes, Lohmann Brown (LB) plus (n = 230) and LB classic (n = 230), were reared for a laying period and subjected to post-mortem parasitological examinations at 79 weeks (LB plus) or 88 weeks (LB classic) of age.There was no significant difference in faecal egg counts between the genotypes. Almost all hens (>99%) were infected with at least one nematode species. Species-specific nematode prevalence ranged from 85.8% to 99.1% between the two genotypes. Heterakis gallinarum was the most prevalent nematode (98.5%), followed by Ascaridia galli (96.2%) and Capillaria spp. (86.1%). Capillaria spp. were composed of C. obsignata (79%), C. caudinflata (16%) and C. bursata (5%).All phenotypic and genetic correlations among worm counts of different parasite species were positive in combined genotypes (rP ranged from 0.05 to 0.30 and rG ranged from 0.29 to 0.88). A strong genetic correlation (rG = 0.88 ± 0.34) between counts of A. galli and H. gallinarum was quantified. Heritability for total worm burden for LB plus and LB classic, respectively, were 0.55 ± 0.18 and 0.55 ± 0.34. Across both genotypes, the heritability of total worm burden was 0.56 ± 0.16.In conclusion, there is a high variation attributable to genetic background of chickens in their responses to naturally acquired nematode infections. The high positive genetic correlation between counts of closely related worm species (e.g. A. galli and H. gallinarum) may indicate existence of similar genetically determined mechanism(s) in chickens for controlling these nematodes. [ABSTRACT FROM AUTHOR]

Lipoptena grahami Bequaert, 1942 (Diptera, Hippoboscidae) was first described in China almost 80 years ago. Species of Lipoptena were obligate blooding-feeding insects and commonly reported as vectors of wild animals of Cervinae. The complete mitochondrial genome of L. grahami was assembled to 16,953 bp in length. The AT content of L. grahami mitogenome is 80.59%. In total, 22 tRNAs, 2 rRNAs, and 13 protein-coding genes (PCGs) were annotated from L. grahami's mitogenome. The typical clover-leaf structure of tRNAs was also analyzed and confirmed except the tRNA-Ser (AGN). A phylogenetic tree was constructed based on L. grahami with some other fly species. [ABSTRACT FROM AUTHOR]

Background: Contemporary teaching in sub-Saharan African medical schools is largely through didactic and problem-based approaches. These schools face challenges from burgeoning student numbers, severe faculty shortages, faculty without instruction in teaching methods and severe infrastructure inadequacies. Team-based learning (TBL) is a pedagogy which may be attractive because it spares faculty time. TBL was piloted in a module on ectoparasites at the Kilimanjaro Christian Medical University College (KCMU Co.). Methods: TBL orientation began six weeks before starting the module. Students were issued background readings and individual and group readiness assessment tests, followed by module application, discussion and evaluation. At completion, student perceptions of TBL were assessed using a 5-point Likert scale evaluating six domains, with a score of 5 being most favourable. Strength of consensus measures (sCns) was applied. Final examination scores were compiled for 2011 (didactic) and 2012 (TBL). Results: About 158 students participated in the module. The mean student scores across the six domains ranged from 4.2 to 4.5, with a high degree of consensus (range 85-90%). The final examination scores improved between 2011 and 2012. Conclusions: KCMU Co. student perceptions of TBL were very positive, and final exam grades improved. These observations suggest future promise for TBL applications at KCMU Co. and potentially other schools. [ABSTRACT FROM AUTHOR]

An alternative approach for the recovery of parasitic copepods from finfishes is proposed herein by applying double-netting (DN) after visual scanning (VS). Double-netting consists of double-filtering the dislodged debris after washing and shaking all dissected parts visually scanned previously. During DN, two different sized hand-nets (≤200 μm in mesh size) are used simultaneously. The debris entangled in the first net is recovered by washing the first net in the second one. A total of 1448 copepods were recovered from nine sparid finfish species by applying DN, accounting for 25% of the total. The most abundantly recovered copepods were bomolochids and philichthyids. Our double-sieving method is efficient in recovering overlooked copepods by VS, providing more accurate results in diversity and quantitative studies. Additional advantages of DN include its simplicity (small size and weight), low price (less than US$ 3), and convenience (easy to transport and apply directly in the field). [ABSTRACT FROM AUTHOR]

Phytochemical investigation of Osyris alba L. (Santalaceae) of Jordanian origin resulted in the isolation and identification of one new pyrrolizidine alkaloid, osyrisine (1), together with 16 other known compounds. The structures of all compounds were established on the basis of spectroscopic analysis. Osyrisine, catechin, and catechin-3-O-α-l-rhamnopyranoside exhibited a significant level of antiparasitic activity against two parasites, Entamoeba histolytica and Giardia intestinalis. [ABSTRACT FROM AUTHOR]

Experiments were first conducted to compare and evaluate different methods of Ascaridia galli larval recovery from the chicken intestine. The number of larvae recovered from the intestinal wall of chickens infected with 1000 embryonated A. galli eggs and killed 15 days post infection (p.i.) by three methods (ethylenediamine tetraacetic acid [EDTA], pepsin digestion and scraping) were compared. The EDTA and pepsin digestion were found to be the most efficient methods with no significant difference (P > 0.05) in the number of recovered larvae between the two. Subsequently, three different A. galli cohorts were established using the polymerase chain reaction-linked restriction fragment length polymorphism (PCR-RFLP) technique. A 533-bp long region of the cytochrome c oxidase subunit 1 gene of the mitochondrial DNA was targeted and 22 A. galli females were allocated to three different haplotypes. The four females with the highest embryonation rate from each haplotype group (total 12 females) were selected and used to inoculate each of 12 chickens with a dose of 1000 embryonated eggs. The chickens were killed 15 days p.i. and A. galli larvae were recovered from the small intestinal wall by the EDTA method and by sieving the lumen content on a 90 µm sieve. DNA of 40 larvae from each of the three different haplotypes was extracted using a worm lysis buffer, and PCR-RFLP analysis of these larvae revealed the same haplotype as that of their maternal parent. The identification of distinguishable cohorts may be a powerful tool in population studies of parasite turnover within the animal host. [ABSTRACT FROM AUTHOR]

The potential of Liriomyza commelinae (Frost) (Diptera: Agromyzidae) as an alternative host for parasitoids of the pest leafminer Liriomyza huidobrensis (Blanchard) was investigated. We particularly focussed on the specific composition of the parasitoid complex and its impact on L. commelinae, frequency of associations, dependency of parasitism on host density and additive effects of species richness on total parasitism. Mined leaves of Commelina erecta (Commelinaceae) were collected from different localities of Cordoba province (Argentina) from 1991 to 1994, and also from different sites of Cordoba city. In total, 25 species of parasitoids (Hymenoptera) were associated with L. commelinae, of which 13 were shared with L. huidobrensis. Chrysocharis flacilla and Diglyphus websteri (Eulophidae) were the most abundant parasitoid species on L. commelinae, the former being the most frequently associated with the leafminer. Total parasitism, averaging 50%, did not depend on parasitoid species richness. No significant relationship was found between parasitism caused by the main species and host abundance. The potential for using the system C. erecta-L. commelinae in the conservation biological control of L. huidobrensis is discussed. [ABSTRACT FROM AUTHOR]

Recent work in the field of parasitology has drawn attention to the application of parasites as pollution-accumulation indicators, particularly cestodes. A discrepancy in metal concentrations within cestode posterior and anterior tissue has led researchers to attribute this phenomenon to metals binding to the shells of their eggs. Thus, the objective of this study was to demonstrate metal presence through the implementation of fluorochromy. Tissue forms of a known metal accumulator, Bothriocephalus acheilognathi, were exposed to a Phen Green FL fluorescent probe specific for metal ions and examined with a fluorescence microscope. The results have shown that metal ions bind to the egg-shells of B. acheilognathi and that fluorescence microscopy can be employed successfully to demonstrate metal accumulation in tapeworms. [ABSTRACT FROM AUTHOR]

The Uzifly, Exorista sorbillans Weidemann, is an endoparasitoid of the the silkworm moth, Bombyx mori L., and can impact commercial sericulture. Effects of Uzifly age, density, temperature and gamma radiation (60Co) on the mass-production of the hyperparasitoid Nysolynx thymus (Girault) were investigated. There was a direct relationship between progeny production and an increase in number of host puparia presented, and a significant decline in the number of progeny with increased host-age. Maximum progeny production was obtained by maintaining a 1:5 to 1:8 parasitoid-to-host ratio for all the age groups. Two to 4-day-old host puparia were most suitable for obtaining the maximum progeny production of N. thymus for all the host-densities. The intrinsic rate of increase (r m day-1) increased with the increased host density for all the host-age groups. The values of net reproductive rate (R 0) and gross reproductive rate (GRR) increased for all the density levels and host age groups. On the other hand, the values for the doubling time (D) and finite capacity of increase (λ) gradually decreased with increased host density for all the host age groups. Host density and host-age significantly influenced the sex-ratio of progeny in N. thymus. Higher proportions of females were observed at higher host density levels and for younger host age groups. The progeny production and sex ratio of the parasitoid varied significantly with temperature. The maximum mean number of progeny was recorded at 25°C, while the minimum was at 30°C. The trend of progeny production at different temperatures was on the order 25 > 20 > 30°C. The highest values for the net reproductive rate (R 0) and GRR for the progeny production were recorded at 25°C compared to 20 and 30°C. Both the values for doubling time of capacity (D) and finite capacity (λ) increased with the trend of 25, 30 and 20°C. The highest value for the intrinsic rate of increase (r m day-1) of progeny production was recorded at 25°C, while the lowest value was at 20°C. The sex-ratios were always female-biased at all the temperatures. Temperature had a significant effect on the longevity of adult N. thymus. The longevity of the adults decreased with an increase of temperature for both sexes. The highest rate of parasitism was observed at 20°C followed by 25 and 30°C. More than 95% parasitism was observed at all temperatures. Gamma irradiation significantly increased the progeny production of N. thymus when reared either on early or late irradiated host puparia, particularly in the parental generation, but irradiated early host pupae were more suitable for mass production of N. thymus than the irradiated late pupae. The sex ratio of parasitoids developing from gamma irradiated host pupae varied significantly. Higher proportions of females were observed for all the dose and host-age groups. [ABSTRACT FROM AUTHOR]

The parasitism of soybean cyst nematode, Heterodera glycines, by the fungi Hirsutella rhossiliensis and Hirsutella minnesotensis and their biocontrol effectiveness against the nematode were investigated in four soils with various pH, texture, and organic matter. Fungal parasitism was assayed in the soils in 25 mL vials. As expected, percentage of H. glycines second-stage juveniles (J2) parasitized by either fungus increased with increasing number of fungus-colonized J2 initially added into the soils. Parasitism of J2 by the fungi was negatively related with soil pH. Both positive and negative relationships with fungal parasitism were observed for soil sandiness and organic matter. In greenhouse study, both fungi at 0.2-0.8 g fresh mycelium of liquid culture per 0.3 L pot and 1% corn-grits culture effectively reduced nematode population density. The relationship between biocontrol effectiveness and the soil factors depended on fungal species and inoculation levels. In general, percentage reduction of egg population density in the soil was negatively correlated with soil pH and positively correlated with sandiness. There was no or weak correlation between egg reduction and organic matter. The percentage of J2 parasitized by the fungi 2 months after planting did not correlate with the soil factors. Plant growth was better in the two soils with intermediate pH and sand than the soil with high pH and low sand or with low pH and high sand. It appeared that soil pH and/or texture are important in influencing biocontrol effectiveness, but further studies are needed to determine the effect of individual factors because they are correlated. [ABSTRACT FROM AUTHOR]

Larval water mites parasitise a wide range of aquatic insects and may have a negative impact on host fitness. One host taxon susceptible to water mite parasitism is the whirligig beetle (Coleoptera: Gyrinidae). We made 11 collections of the whirligig beetle Dineutus nigrior Roberts from May to October of 2006 to investigate patterns of water mite parasitism on that host species. Mites were identified as of the genus Eylais. Mite intensity ranged from 1 to 11. Median intensity was 1.0 and ranged from 1.0 to 3.0 for individual samples. There did not appear to be temporal patterns in mite intensity. Prevalence was 30.9% but varied substantially over the sampling period ranging from 2.5 to 63.3%. Mites were attached to the metathoracic wings and the body tergites under the elytra. When all samples were considered there was equal use of wings and body tergites but there was temporal variation in the use of attachment sites. [ABSTRACT FROM AUTHOR]

The potato tuber moth Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) is a major agricultural pest of solaneceous crops in warm countries worldwide. The encyrtid polyembryonic parasitoid Copidosoma koehleri (Blanchard) has been successfully introduced for biological control of the moth in potato fields in South Africa and Australia; however, augmentative releases of the parasitoid in trial plots and in commercial potato fields in Israel did not reduce pest populations or infestation levels more than chemical treatment. Copidosoma koehleri accounted for 4-5% of parasitism on tuber moth caterpillars, while most parasitism was due to local species of larval parasitoids. The abundance and composition of local parasitoids did not differ between C. koehleri release plots and conventionally treated control plots. These findings can be interpreted as failure of the introduced parasitoids to survive and locate their hosts, or as mortality of C. koehleri within hosts in the field. Sentinel hosts, placed in trial plots and collected after 24 h, were rarely parasitised by C. koehleri, supporting the first interpretation. To test the second hypothesis, hosts parasitised by C. koehleri were placed in field plots for a week, collected, and reared out in the laboratory. The emergence rates of C. koehleri from these hosts resembled those of lab-reared controls, suggesting that mortality within hosts in the field is not a major cause of C. koehleri's poor biocontrol performance. [ABSTRACT FROM AUTHOR]

The diel oviposition periodicity of females of the LSHTM strain of Aedes aegypti was studied, under laboratory conditions, using one female/cage and monitoring, by changing the substrate, every 1, 2, 4 or 24 h. The individual females monitored at hourly intervals showed peak oviposition at 18.00–19.00 hours (a period when 44% of the eggs observed were laid) whereas the individuals monitored at two-hourly intervals showed peak oviposition between 16.00–18.00 hours (38% of eggs). The four-hourly monitoring gave a result that was similar to that of the two-hourly monitoring, with 79% of eggs laid between 14.00–18.00 hours, indicating an earlier peak in oviposition than seen with the one-hourly monitoring. Care should therefore be taken when conducting similar studies in the laboratory and when comparing or considering data derived from experiments in which different monitoring intervals have been employed. [ABSTRACT FROM AUTHOR]

This study examined the frequency of Strongyloides stercoralis infection in patients with gastrointestinal cancer through parasitological and immunological tests. A total of 77 patients were evaluated, 33 with gastrointestinal cancer and 44 controls with other types of cancers. All the patients were undergoing chemotherapy and 14 (18.2%) were receiving concomitant radiotherapy. For a parasitological diagnosis, we applied the Baermann and Lutz methods. The immunological diagnosis involved the indirect fluorescence antibody test (IFAT) and enzyme linked immunosorbent assay (ELISA) to detect IgG antibodies using Strongyloides ratti antigens. The frequency of positive S. stercoralis in gastrointestinal cancer diagnosed by parasitological methods was 3 cases (9.1%), by serology it was 8 cases (24.2%). In the control group 1 case (2.3%) of S. stercoralis was diagnosed by parasitological methods and 2 cases (4.5%) by immunological tests (p<0.05). Patients with gastrointestinal cancer had a 6.7-fold greater chance of testing positive for S. stercoralis infection. Our data highlight the importance of parasitological and immunological diagnosis for S. stercoralis in patients with gastrointestinal cancer living in endemic areas of strongyloidiasis, since they have a higher risk of becoming infected with S. stercoralis than patients with other types of cancer. [ABSTRACT FROM AUTHOR]

Intraguild predation (IGP) is pervasive in many managed and unmanaged ecosystems and may have negative, neutral or positive effects on the biological control of pest insects. Both generalist predators and aphelinid parasitoids attack Bemisia tabaci (Gennadius) Biotype B (=B. argentifolii Perring & Bellows) on cotton in the southwestern USA. Free-choice and no-choice laboratory assays were conducted to quantify prey consumption patterns and preference by three representative generalist predators, Geocoris punctipes (Say), Orius insidiosus (Say), and Hippodamia convergens Guérin-Méneville, offered fourth instar B. tabaci nymphs and nymphs parasitized by Eretmocerus sp. nr. emiratus. All three predators showed a significant preference for larval and pupal stage parasitoids over early fourth instar nymphs, but G. punctipes and O. insidiosus were non-discriminating when offered a choice of larval parasitoids and late fourth instar nymphs. The potential implications of these observed patterns for the field were examined through sensitivity analyses of existing field life table data. First, preference for parasitized hosts alters the methods required for calculating marginal rates of parasitism. Incorporating a preference variable in the estimation procedure had a very small positive effect (0.02-1.13% change) on total generational mortalities observed in previous life table studies. However, further hypothetical analyses suggested that under circumstances of lower generational mortality and higher levels of either apparent parasitism or predation, high levels of predator preference for parasitized prey could alter estimates of total mortality as much as 14%. Second, although intraguild predation was demonstrated, the implications for biological control are unclear. Based on field life table data the rate of IGP ranged from 0.019 to 0.126 depending on predator species and prey comparison, but accounting for these levels of IGP had only small negative effects on total generational mortalities (0.193-1.278% change). [ABSTRACT FROM AUTHOR]

Parasitism of tarnished plant bug nymphs, Lygus lineolaris (Palisot de Beauvois) was investigated on different weeds and on lettuce, celery and alfalfa-clover, in a muck soil area of southwestern Quebec. The phenology of parasitism, defined as the time during which female parasitoids are active in the field, was evaluated. Two nymphal parasitoid species were found: Peristenus pallipes (Curtis) and P. pseudopallipes (Loan). Lygus lineolaris was most abundant on stinging-nettle with levels of parasitism of 17% (P. pallipes) and 27% (P. pseudopallipes) and on alfalfa-clover with levels of parasitism of 25% (P. pallipes) and 8% (P. pseudopallipes). On lettuce, parasitism by P. pseudopallipes was below 4% while no parasitism was observed on celery. The dissection and rearing methods were used to estimate parasitism, and dissection usually yielded parasitism levels higher than rearing. Degree-days requirements of both host and parasitoids were used to calculate the period of activity of parasitoid adults. The estimates of adult activity were 47 days from late May to early July for P. pallipes, and 42 days from mid-July to late August for P. pseudopallipes. [ABSTRACT FROM AUTHOR]

Mathematical modelling has been used to assess the level of malarial transmission, during the dry season, in Nouna province, in north–western Burkina Faso. The data used were collected, at four sites (one semi-urban and three rural), from 867 children aged 6–60 months who were randomly selected. Almost all of the children (850) completed the follow-up, which involved the active detection of malaria (i.e. febrile, smear-positive malarial infection) throughout a single dry season (December 2003–May 2004). Light traps were used to sample the local populations of Anopheles vectors, in order to estimate the daily biting rate. The mathematical model was then used to simulate the incidence of malaria, which was compared with the observed incidence. At all four study sites, new cases of malaria were observed throughout the dry season, although the level of transmission was low. The monthly incidence of malaria estimated using the mathematical model was very close to the observed incidence. The fit was sensitive to daily mosquito survival and daily human parasite clearance. In Nouna province, effective interventions to prevent malaria should not be confined to the rainy season but must continue throughout the year. The focus should be on the clearance of parasitaemias, by the use of effective drugs, and on decreasing vector survival, by the use of vector-control methods. [ABSTRACT FROM AUTHOR]

In Ghana in 2004 (when choroquine was still the nationally recommended drug for the first-line treatment of malaria), the sensitivities, to chloroquine, amodiaquine, quinine, mefloquine, artesunate and halofantrine, of 60 Plasmodium falciparum isolates from two ecologically distinct areas of the country were assessed in vitro. The aim was to make available, to policy-makers, the field-based evidence needed to review the national strategy for malaria treatment. Drug susceptibilities were explored using the standardized protocol of the Antimalarial Drug Resistance Network. Although 32 of the P. falciparum isolates evaluated (56.1% of the 57 isolates successfully investigated for their susceptibility to choroquine) showed resistance to chloroquine and two showed slightly reduced sensitivity to amodiaquine, all the isolates were sensitive to mefloquine, artesunate, quinine and halofantrine. The median inhibitory concentrations (IC50) of chloroquine were positively correlated with those of quinine (r=0.4528; P=0.0008) but not those of any of the other drugs investigated. The IC50 of amodiaquine and artesunate were also positively correlated (r=0.3703; P=0.0067). These results provide evidence of the presence, in Ghana, of P. falciparum isolates that are highly resistant to chloroquine but generally sensitive to most of the other antimalarial drugs commonly used in the country. Partly in consequence of these observations, the recommended first-line treatment for malaria in Ghana was changed to an amodiaquine–artesunate combination in January 2005. [ABSTRACT FROM AUTHOR]

Although cercarial dermatitis is an emerging disease world-wide, cases of such dermatitis may often go undiagnosed, especially in communities that are affected by various skin infections. Between August 2001 and July 2002, 1336 individuals from tribal villages in central India were examined for dermatitis. Skin scrapings were collected and examined for Sarcoptes scabiei and each subject's response to antiscabies treatment was recorded. Freshwater snails were collected from the local ponds used for bathing, and examined for cercariae. The recorded prevalence of dermatitis ranged between 2.1% and 12.5% during the study year, peaking at the end of winter (February–March) and during the rainy season (August–October). Snail positivity for cercariae peaked in the rainy season. The prevalence and the severity of dermatitis were both higher in children than in adults. As most recorded cases of dermatitis were associated with a rash that developed soon after bathing in the local pond, all the skin scrapings were negative for itch mites, and the response to antiscabies treatment was poor, most if not all of the dermatitis observed was probably cercarial. Cercarial dermatitis therefore appears to be a significant health problem among the tribal populations of central India. [ABSTRACT FROM AUTHOR]

It is possible to detect and distinguish Leishmania parasites using PCR-RLFP — a combination of PCR and analysis of the fragment-length polymorphism seen when the amplicons are digested with one or more restriction enzymes. In the present study, clinical samples from 24 Jordanians suspected to have cutaneous leishmaniasis and cultures set up using leishmanial parasites from five Greek dogs were investigated using PCR, in which the internal-transcribed-spacer-1 (ITS1) region of the parasites' ribosomal-RNA gene was amplified, followed by HaeIII digestion of the resulting amplicons. The cultures, which were all maintained in Leibowitz L-15 medium with 20% foetal calf serum, were each investigated as serial dilutions. Using the PCR-RLFP analysis, each culture was identified as L. donovani and each was found positive for this parasite with a mean sensitivity of 66%–100% (depending on the culture dilution tested), a specificity of 100%, a mean positive predictive value of 100%, and a negative predictive value of 74.6%–100%. When simulated clinical samples, created by mixing human blood with known numbers of L. donovani promastigotes, were investigated, the PCR-RFLP gave optimal results (with a value of 100% each for sensitivity, specificity and positive and negative predictive values). When the real clinical samples (25 lesion aspirates and 20 samples of peripheral blood from 24 Jordanian patients) were investigated using the molecular method, 20 (84%) of the patients were found to have lesion aspirates that were PCR-RFLP-positive for L. major (although, by microscopy, only six were found to have amastigote-positive lesion aspirates). None of the blood samples from the Jordanian patients, however, was found PCR-positive. [ABSTRACT FROM AUTHOR]

The zoonotic liver flukes Fasciola hepatica and F. gigantica co-exist in parts of Africa and Asia. The two species have similar life-cycles but different transmission characteristics. Although the identification of adult Fasciola to species level is traditionally based on differences in size and shape, recent studies have demonstrated this method to be unreliable. Species of Fasciola can be distinguished by staining and comparing the morpho-anatomy of the gut and ovaries or by iso-enzyme analysis but such approaches are time-consuming and require specialist skills. Two primer sets, based on RAPD-derived sequences from English F. hepatica and Ghanaian F. gigantica, can now be used, in two separate PCR, to distinguish F. hepatica from F. gigantica. When the PCR were used to investigate 10 flukes (five from the U.K. and five from Peru) morpho-anatomically identified as F. hepatica and 10 (five from Ghana and five from Sudan) morpho-anatomically identified as F. gigantica, all 20 flukes were correctly identified to species level. The PCR were validated using 175 flukes collected, over a 12-year period, from different countries and both cattle and sheep. [ABSTRACT FROM AUTHOR]

In filariasis-endemic areas beyond sub-Saharan Africa, the World Health Organization's recommended strategy for interrupting transmission of the causative parasites is annual, single-dose, mass treatment with a combination of diethylcarbamazine (DEC; given at 6 mg/kg) and albendazole (ALB; given at 400 mg) for 4–6 years (the minimum estimated life-span of the adult parasites). In an open, hospital-based, randomized and controlled trial, with a blinded evaluation of outcome, 82 children and adolescents from Recife, all with Wuchereria bancrofti microfilaraemias, were given either DEC alone (6 mg/kg) or the same dose of DEC combined with ALB (at 400 mg/patient). Every 90 days for 1 year after the single treatment, each patient was checked for microfilaraemia by the filtration of up to 5 ml of venous blood collected at night. One year post-treatment, 16 (39%) of the 41 patients given DEC alone and 20 (49%) of the 41 given DEC–ALB were found microfilaraemic (relative risk=0.8, with a 95% confidence interval of 0.49–1.31) and the corresponding geometric mean levels of microfilaraemia were 2.0% and 1.8% of the levels recorded immediately pre-treatment, respectively (P>0.05). In terms of the prevalences and intensities of microfilaraemia, therefore, the addition of ALB to the DEC appeared to offer no significant benefit. [ABSTRACT FROM AUTHOR]

Attempts have been made to transfer Wolbachia from infected to uninfected, laboratory-reared Phlebotomus papatasi, through mating, and to determine whether the incompatibility phenotype could be expressed through crosses between infected and uninfected flies. In order to test for the intraspecific transmission of Wolbachia in crosses between infected females and uninfected males, or those between uninfected females and infected males, a PCR based on Wolbachia -specific wsp primers was used to test the progeny of each cross and, subsequently, 50 individual flies from the F3 generation. All the individual flies tested from the F1 progeny of the crosses between infected males and uninfected females were found to be uninfected. In the crosses involving infected females and uninfected males, however, Wolbachia were found in the progeny of five matings out of the 23 that produced viable eggs. In the F3, Wolbachia were not detected in any of the individuals resulting from the cross between uninfected females and infected males but they were detected in 52% (26) of the 50 tested individuals resulting from the cross between infected females and uninfected males. No evidence of cytoplasmic incompatibility (CI) was observed in any of the crosses. The absence of CI expression and relatively low frequencies of maternal transmission could hamper the potential use of Wolbachia in a transgenic strategy for the control of leishmaniases. [ABSTRACT FROM AUTHOR]

The present study evaluated the efficacy and wash resistance of three types of commercial, deltamethrin-treated nets (PermaNetTM, YorkoolTM and A-Z nets) — that their manufacturers claimed to be long-lasting insecticidal nets (LLIN) — and those of nets conventionally treated with deltamethrin, at either 23–27 mg/m2 (using one K-O Tab H tablet/net) or 46–54 mg/m2 (using two K-O Tab tablets/net). The nets were tested unwashed or after being washed, by hand or machine, five or 15 times. After each wash, the nets were dried vertically on a line, in the shade, for 8 h. Insecticidal activity was assessed, using two types of bio-assay and wild-caught female Anopheles stephensi, as mean median knock-down times and as mortality 24 h after a 3-min exposure. For each type of nets tested, the insecticidal activity of the unwashed nets was greater than that of the nets washed five washes, and that of the nets washed five times was greater than that of the nets washed 15 times, with the latter decline considerably greater than the former. The pattern of decrease, however, differed with net type. The PermaNet and A-Z nets generally had the highest insecticidal activity, and, overall, the Yorkool nets did not perform significantly better than the conventional nets treated with 23–27 mg deltamethrin/m2. Although washing with detergents can clearly remove insecticide from the fibres of all types of treated nets, the consequent loss of activity varies with net type. After 15 washes, the PermaNet nets showed higher insecticidal activity than any other net type but there is still scope for the manufacturer of the PermaNet nets to improve wash resistance. [ABSTRACT FROM AUTHOR]

In the Gurage zone of central Ethiopia, the association between fly density and the occurrence of trachoma has been investigated across varying altitudes. The seasonal pattern of fly density in the area was also explored. When, over short sampling periods (10 min/child indoors and 10 min/child outdoors), hand nets were used to collect flies from the eyes of children aged 2–8 years, only Musca sorbens and M. domestica were caught. Almost all of the 13,147 'eye-seeking' flies collected came from villages at low (<2000 m; 40.7%) or mid altitudes (2200–2500 m; 58.6%) with only 0.7% of them caught in the high-altitude villages investigated (at >3000 m). Musca sorbens predominated outdoors and M. domestica indoors. Almost all (99.3%) of the eye-seeking M. sorbens collected were caught outdoors whereas most (76.7%) of the M. domestica were caught indoors (P<0.0001 for each). The median numbers of flies caught, per child, per 10-min collection, in the low-, mid- and high-altitude villages were 9.5, six and zero, respectively, for M. sorbens, and eight, three and zero, respectively, for M. domestica. The altitudinal trends in these numbers of 'eye-seeking' flies matched those in the prevalences of active trachoma among children aged 1–10 years, which were high in the villages at low (81.6%) and mid altitude (78.7%) but much lower (1.7%) in the high-altitude villages. In conclusion, trachoma is a common disease of public-health importance only in the low- and mid-altitude villages in the Gurage zone, where there are large numbers of eye-seeking flies, and not in the villages that lie >3000 m above sea level, where there is a dearth of such flies. [ABSTRACT FROM AUTHOR]

The article presents a study about the detection of Trypanosoma cruzi in Triatoma infestans. The primary aim of the study is to explore and compare the potential usefulness of polymerase chain reaction (PCR) and direct microscopical examination for detecting Trypanosoma cruzi infection in bugs used for xenodiagnosis.

I consider how two fundamental aspects of parasitology and population genetics--macroparasite aggregation among hosts and the Hardy-Weinberg principle--govern the theoretical impact of transgenic forms of a possum-specific nematode Parastrongyloides trichosuri, that cause female infertility, on brushtail possum (Trichosurus vulpecula) populations. Assuming chromosomal inheritance of transgenes, the conditions under which transgenic P. trichosuri would be an efficacious tool for eradication are predicted to be severely limited, given the level of aggregation with which this parasite occurs naturally in its host. These limits indicate that a transgenic form of P. trichosuri, containing a chromosomally-inherited female infertility transgene, would need to cause near total infertility in all host females infected with a single such parasite, for eradication to be realistically possible. Relatively greater effort is predicted necessary to achieve thresholds for eradication when transgenic nematodes are introduced to hosts already infected by the parasite compared with populations free of the parasite. Under such circumstances, the predicted effort required is reduced if transgenes are dominant as opposed to recessive, and introduced in homozygous as opposed to heterozygous form. [ABSTRACT FROM AUTHOR]

We have recently evaluated an ELISA for the diagnosis of human schistosomiasis using S. bovis adult worm antigens (AWA Sb), showing a sensitivity of 94% and a specificity of 97% for patients diagnosed by egg detection. Nevertheless, the comparison of this AWA Sb ELISA with direct parasitological findings as the gold standard could introduce a selection bias, due to the well-known lack of sensitivity of direct methods in the detection of acute schistosomiasis and of low burden infections. The objective of the present work is to compare it with parasitological methods and commercial indirect haemagglutination test using S. mansoni antigens (WA Sm IHA) in 254 immigrants and travellers with different clinical settings; in addition, to find specific bands in the EITB of different phases of schistosomiasis. The AWA Sb ELISA showed 72% of seropositivity in patients with Katayama fever, while patients with eosinophilia and genito-urinary complaints showed 27% and 93%, respectively. The diagnosis yield was globally higher than direct egg detection or WA Sm IHA test with regard to the clinical setting. Finally, the utilization of EITB with S. bovis AWA permits the confirmation of diagnosis in chronic and acute phases of the disease. [ABSTRACT FROM AUTHOR]

Host-discrimination behavior by the koinobiont parasitoid, Psyllaephagus pistaciae Ferrière (Hymenoptera: Encyrtidae), the major biocontrol agent of the common pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer (Hemiptera: Psyllidae), in Iran, was investigated in the laboratory. The results demonstrated that P. pistaciae quickly detected and avoided freshly parasitized hosts, either after antennating or by probing with their ovipositor. However, this discriminatory ability declined with time, probably influenced by both external and internal markers left by the previous ovipositing female. The results also confirmed that female P. pistaciae responded to changes in host quality associated with the parasitoid's larval development 4 days after the initial parasitization, clearly indicating that the second female could detect the presence of the larvae and adjust her host-selection decision. In addition, psyllid nymphs treated topically with a solution of Dufour's gland were rejected by the parasitoid, showing that Dufour's gland secretion had a significant effect as a host marking chemical. The current study also showed that superparasitism increased the host-mortality and that the rate of encapsulation decreased, suggesting that, when two eggs are laid in the same psyllid nymph, only one parasitoid develops to an adult. [ABSTRACT FROM AUTHOR]

Beneficial arthropods were monitored in monthly plantings over 4 years in a rainfed, triple-maize cropping system in southern Mindanao, Philippines. Generalist predators and two egg parasitoids of the Asian corn borer Ostrinia furnacalis (Guenée) (ACB) did not show significant differences in abundance with respect to calendar month of planting over 39 crops. Two species of Trichogramma (T. evanescens Westwood and T. chilonis Ishii) collectively parasitized 67% of ACB egg masses and 58% eggs over the study becoming more abundant as the crop aged. The closeness of the two parasitism rates suggests that to increase parasitoid efficacy, particularly early in the crop, the best strategy would be augmentation and to increase longevity of wasps by providing carbohydrate sources to extend their searching time. Unparasitized egg masses tended to be smaller showing they were more likely to be overlooked. The ratio between the two parasitoids was 56:44 in favour of the former. Trichogramma evanescens had been introduced 2 years earlier by a government project, whereas T. chilonis probably was introduced by sugarcane estates. Prior to their introduction there were no ACB egg parasitoids in the Philippines and both are firmly established as annual parasitism levels did not continue to rise during the study. Parasitoid activity caused significant reductions in neonate ACB larval numbers beginning 7 weeks after crop emergence in an average crop. Egg parasitism rates were positively and linearly correlated with ACB egg mass density. A quadratic regression model was established between mean egg parasitism rates and egg masses size with peak parasitism rates occurring at 25 eggs per mass. Collectively 32 species of generalist predators averaged 0.9 - 1.5 individuals per plant based on weekly samplings. If ants were excluded, the average dropped to 0.1 - 0.3 per plant. Ants, dominated by Solenopsis geminata (F.), fed on ACB eggs and larvae. Coccinellids as the next most numerous were represented by three species where Micraspis crocea (Mulsant) in particular tracked ACB egg masses and probably the corn leaf aphid Rhopalosiphum maidis (Fitch) as well. Four species of orthropterans also tracked ACB egg masses. The third most abundant guild was 17 spiders with the oxyopid Oxyopes javanus Thorell and the araneid Araneus inustus (C.L. Koch) highly correlated with ACB egg mass densities. Other spiders targeted ACB moths and Atherigona oryzae Malloch adults. The predatory mirid Cyrtorhinus lividipennis Reuter probably targeted the corn leafhopper Cicadulina bimaculata (Evans) and possibly thrips Thrips palmi Karny and Megalurothrips usitatus (Bagnall). The lacewing Chrysopa sp. was abundant late in the crop when aphids were present on tassels. [ABSTRACT FROM AUTHOR]

The outcome of multiparasitism by two pupal parasitoids, the exotic solitary ichneumonid Xanthopimpla stemmator and the indigenous gregarious eulophid Pediobius furvus, was studied using the invasive crambid stem borer Chilo partellus and the indigenous noctuid Busseola fusca as hosts. Two parasitism sequences were observed, where X. stemmator oviposited before P. furvus , and vice versa. In addition, the effect of time between first and second parasitism on parasitoid emergence, development, sex ratio, and number of offspring was assessed. For most treatments, time interval between parasitism had no significant effect on the percentage if pupae producing either P. furvus or X. stemmator . In general, X. stemmator outcompeted P. furvus irrespective of the order of oviposition, time interval between ovipositions and host species. Further studies, especially on host finding capacity of the two parasitoid species are required to determine the competitiveness of the two species under field conditions. [ABSTRACT FROM AUTHOR]

We evaluated a technique that used ablated sections of corn stalks infested with larvae of Diatraea saccharalis F. to assess parasitism by Cotesia flavipes (Cameron) in a corn field. Stalkborer larvae were retrieved successfully from the artificially infested, ablated stalks for at least 96 h after deployment in the field. Levels of parasitism in ablated stalks attached to corn plants were comparable to levels of parasitism measured using whole plants that were artificially infested. Olfactometer comparisons showed preference by female C. flavipes for both whole plants and ablated stalks containing larval D. saccharalis , over uninfested stalks and plants. This technique provides a means to estimate parasitism of stalkborer larvae by C. flavipes without destructive sampling of agronomic plants. [ABSTRACT FROM AUTHOR]

Eleven years after they had been given itraconazole or allopurinol for the treatment of chronic American trypanosomiasis, 109 adult patients were checked for electrocardiographic abnormalities and evidence of Trypanosoma cruzi infection. The parasitological investigations included xenodiagnosis, in which the faeces of Triatoma infestans that had fed on the patients were checked under the microscope for flagellates. In addition, a PCR-based assay and a hybridization assay were used to test blood samples from the patients, and faeces from the Tri. infestans that had fed on the patients, for Try. cruzi DNA. For the data analysis, the patients were divided into four groups known as normal/normal, abnormal/normal, normal/abnormal and abnormal/abnormal, according to whether the patients had been found to have normal or abnormal electrocardiograms (ECG) shortly before the first treatment and to have normal or abnormal ECG when checked at the 11-year follow-up. The 51 normal/normal and 24 normal/abnormal patients were assumed to have been in the 'indeterminate' phase of the disease when they were treated, whereas the 16 abnormal/normal and 18 abnormal/abnormal patients all had evidence of chagasic cardiopathy at that time. When checked 11 years post-treatment, 40 (78.4%), 17 (70.8%), 14 (87.5%) and 17 (94.4%) of these patients, respectively, were each found positive for Try. cruzi in at least one of the parasitological tests. The hybridization assay, whether applied to human blood or bug faeces, appeared a significantly more sensitive test than the PCR-based assays or microscopically assessed xenodiagnosis (P<0.05). Only the 21 patients who appeared to be negative for Try. cruzi could be considered parasitologically cured (although all still appeared to have anti-Try. cruzi antibodies in their blood). Only 13 of these parasitologically cured patients (seven of those treated with itraconazole and six of those given allopurinol) had normal ECG at the 11-year follow-up. In Chile at least, itraconazole, which caused fewer adverse effects than the allopurinol while being no less effective at preventing cardiopathy, appears to be the drug of choice to treat chronic American trypanosomiasis in adults. [ABSTRACT FROM AUTHOR]

The value of a direct agglutination test (DAT) in the detection of subclinical infections with Leishmania donovani has recently been investigated in the Indian state of Bihar, after the sensitivity and specificity of the test had been determined. When used to screen sera from 108 parasitologically confirmed cases of visceral leishmaniasis, 50 patients with active, non-leishmanial infection, and 641 healthy controls living close to, or distant from, an endemic area, the test was found to be 91.7% sensitive and 100% specific if a titre of 1 : 800 was used as the threshold for seropositivity. During a longitudinal clinical study in a rural, VL-endemic area of the Indian state of Bihar, the test was used, with 1 : 800 set as the threshold titre, to determine the baseline prevalence of infection with L. donovani among villagers who, though showing no symptoms of VL, had recently been febrile for at least 2 weeks. The 234 subjects of this study were either VL-case contacts [i.e. members of households in which there were active or cured VL cases (N=78)] or the members of control households with no cases or history of the disease (N=156). The results of DAT at the start of the study indicated that 49 (20.9%) of the subjects — 29 (37.2%) of the VL-case contacts and 20 (12.8%) of the other subjects — were seropositive and therefore probably had subclinical infections with L. donovani. During the subsequent 9 months of follow-up, however, only eight of the subjects found seropositive at the start of the study — seven (24.1%) of the seropositive case contacts but only one (5.0%) of the other seropositives — developed symptomatic VL, all by month 6 of the follow-up. Compared with their neighbours, therefore, individuals who shared households with active or cured cases of VL appeared at greater risk not only of L. donovani infection (indicating focal transmission) but also of developing symptomatic disease once infected. Curiously, among the seropositive case contacts, those from the households that harboured active cases of VL at the baseline survey were less likely to develop symptomatic VL during the 9 months of follow-up than those from households that harboured only cured cases (18.8% v. 30.8%). The wide-spread use of DAT could allow the detection and early treatment of latent L. donovani infections and so contribute to the elimination of VL, at least as a public-health problem, from India. [ABSTRACT FROM AUTHOR]

In a study of the phlebotomine sandflies (Diptera: Psychodidae) in a forest reserve in Recife, Pernambuco state, north–eastern Brazil, the sandflies landing on human bait between 1.00 and 1.42 h after sunset were collected weekly for 2 years. Although 10,287 sandflies of 10 Lutzomyia species were collected, almost all (96.5%) of the sandflies caught were Lu. umbratilis. This species and several others caught are potential vectors of some of the Leishmania parasites that cause human disease. The recorded landing rate for Lu. umbratilis peaked, at the high level of 333.3 flies/person-hour, during the collections made in May 2003. The relative rarity in the collections of males of some of the species caught probably indicates that these species do not lek on their bloodmeal sources. It is likely that the sizes of the local populations of species that are not very anthrophilic, such as Lu. flaviscutellata, are much larger than indicated by the collections made on human bait. [ABSTRACT FROM AUTHOR]

As a tick feeds, its saliva induces innate and acquired immune responses in the host, including leucocyte infiltration into the bite site. Tick salivary glands produce molecules, however, that counteract many host defences against blood feeding. The effects of salivary-gland extracts (SGE) of Dermacentor andersoni and Ixodes scapularis on the expression of various adhesion molecules [E-selectin, P-selectin, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1)] by the sEND.1 cell line (which is based on cells from the subcutaneous tissue of mice) have now been investigated in vitro. The effects were found to differ with the tick species. The SGE of D. andersoni significantly down-regulated the expression of ICAM-1, whereas a similar extract prepared from I. scapularis significantly reduced the expression of P-selectin and VCAM-1. Tick salivary proteins therefore appear to have direct effects on adhesion-molecule expression, in addition to their previously established roles in down-regulating the pro-inflammatory cytokines that activate endothelial cells. It remains unclear exactly how the reduction of adhesion-molecule expression in the host's endothelial cells benefits the feeding tick but it may alter leucocyte migration to the bite site and/or reduce antigen presentation by the endothelial cells. It may also modulate the interactions between the host's leucocytes and any tick-borne pathogens, during initial infection of the endothelium. [ABSTRACT FROM AUTHOR]

This article discusses comparative effects of pyrimethamine-sulfadoxine, with and without probenicid, on Plasmodium falciparum gametocytes in children with acute, uncomplicated malaria. The article presents a study in this regard. The treatment of acute, Plasmodium falciparum malaria with pyrimethamine-sulfadoxine is often associated with drug-induced increases in the frequency of gametocyte carriage and the level of gametocytaemia. When pyrimethamine-sulfadoxine is used in combination with other antimalarial drugs, particularly with amodiaquine or the artemisinin derivatives, however, these unwelcome changes may be considerably reduced. The article further focuses on the study.