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ABSTRACT The Sydney rock oyster (Saccostrea glomerata) forms the basis of an important aquaculture industry on the east coast of Australia. During the 1970s, production of S. glomerata began to [...]

Invertebrates lack adaptive immune systems homologous to those of vertebrates, yet it is becoming increasingly clear that they can produce diversified antigen recognition molecules. We have previously noted that the snail Biomphalaria glabrata produces a secreted lectin, fibrinogen-related protein 3 (FREP3), unusual among invertebrate defense molecules because it is somatically diversified by gene conversion and point mutation. Here we implicate FREP3 in playing a central role in resistance to a major group of snail pathogens, digenetic trematodes. FREP3 is up-regulated in three models of resistance of B. glabrata to infection with Schistosoma mansoni or Echinostoma paraensei, and functions as an opsonin favoring phagocytosis by hemocytes. Knock-down of FREP3 in resistant snails using siRNA-mediated interference resulted in increased susceptibility to E. paraensei, providing a direct link between a gastropod immune molecule and resistance to trematodes. FREP3 up-regulation is also associated with heightened responsiveness following priming with attenuated digenetic trematodes (acquired resistance) in this model invertebrate immune system. host-parasite interactions | evolution | immunology | parasitology | schistosorniasis doi/ 10.1073/pnas.1011242107

BACKGROUND: Sanitation affects health, especially that of young children. Residents of Salvador, in Northeast Brazil, have had a high prevalence of intestinal parasites. A citywide sanitation intervention started in 1996 [...]

Our review of angiostrongyliasis in China found that the disease is emerging as a result of changes in food consumption habits and long-distance transportation of food. Enhanced understanding of angiostrongyliasis [...]

ABSTRACT Background Bilharzia is one of the major parasitic infections affecting the public health and socioeconomic circumstances in (sub) tropical areas. Its causative agents are schistosomes. Since these worms remain [...]

Breeding for host resistance to parasites has become an imperative in many sheep industries. Because of the widespread use of AI in sheep breeding schemes, it is important to understand how the performance of offspring from rams varies in different flock environments, both for resistance to parasites and key production traits. This study used both variance component and reaction norm models to investigate the level of genotype x environment interaction for fecal egg count (FEC) and important Merino production traits in a range of flock environments in Australia These flocks were linked by the use of common rams in a sire-referencing scheme. Both linear and quadratic polynomial reaction norm models were used. The heritability of these traits and the genetic correlation between them and FEC also was investigated using the reaction norm model. A contemporary group (CG) was defined by a flock, year, age class, sex, and paddock combination. Each CG environment was characterized by the mean value of any given trait for that CG. The recorded data used in the study were analyzed in a standardized form. Standardization for each trait was achieved within a CG by subtracting the CG mean from each observation and dividing by the CG SD. The genotype x environment effect accounted for Key Words: Fecal Egg Count, Gastrointestinal Parasites, Genetic Parameters, Genotype x Environment Interaction, Reaction Norm, Sheep

Objective: To assess the effects of multi-micronutrient supplementation and multi-helminth chemotherapy on serum retinol concentration, using schools as a health delivery system. Study area and population: From 19 primary schools in Bondo District, western Kenya, 977 children between 9 and 18y were included in the trial. The 644 (65.9%) children on whom baseline serum retinol was available were included in this study. Design: A randomised, placebo-controlled, double-blind, two-by-two factorial trial on the effects of multi-micronutrient supplementation and multi-helminth chemotherapy on serum retinol after 8 months. Intervention: Single treatment with albendazole (600 mg) and praziquantel (40 mg/kg of body weight) and daily multimicronutrient supplementation with tablet containing 1000ILg vitamin A. Results: Micronutrient supplementation (0.08 [micro]mol/l, 95% CI 0.01, 0.14; P=0.025), but not treatment (0.03 [micro]mol/l, 95% CI -0.04, 0.10; P=0.38), increased serum retinol. However, treatment did increase serum retinol in S. mansoni-infected (0.09, 95% CI 0.02, 0.16; P=0.009), but not in uninfected children (-0.07, 95% CI -0.18, 0.03; P=0.18; interaction, P=0.01). Similarly, reduction in egg output of S. mansoni, but none of the geohelminth, was a predictor, corresponding to a 0.008 [micro]mol/l (95% CI 0.00002, 0.02; P=0.049) increase in serum retinol per 100 epg reduction. Interestingly, interactions were found between age and sex (P=0.046), and malaria parasitaemia and sickle cell phenotype (P=0.04). Conclusion: Multi-micronutrient supplementation and reduction in S. mansoni egg output increased serum retinol, irrespective of initial serum retinol. Sponsorship: The Danish International Development Assistance. doi:10.1038/sj.ejcn.1601376 Keywords: micronutrients; anthelminthic treatment; malaria; S. mansoni; hookworm; T trichiura; A. lumbricoides; vitamin A; school children; Kenya, Introduction Vitamin A deficiency is widespread in developing countries, particularly in young children and women where it is an important cause of immune function impairment (Semba, 1994) and increased risk [...]

Current estimates of the global prevalence of parasitic diseases range from 600 million cases caused by protozoan and metazoan parasites (Kolberg 1994) to more than 1 billion total cases (Goodman [...]

A study discovered that trifluralin, a microtube-disrupting herbicide, inhibits Leishmania amazonensis. This finding resulted from analyzing trifluralin's in vitro impact on various species of trypansomatid protozoans. Existing chemotherapies and pentavalent antimonials only produce side effects when used to treat this tropical disease called Leishmaniasis. The discovery has implications for the treatment of other related tropical diseases.

Schistosomiasis is an parasitic infection caused by a blood fluke of the species, Schistosoma haematobium. S. haematobium infection involves the portal system and the mesenteric veins of the bladder and rectum. Infected persons excrete parasitic eggs through their urine. This study examined the effectiveness of chemotherapy with the drug metrifonate in an infected population in both decreasing the prevalence of heavy infection (excretion of 50 or more eggs per 10 milliliters of urine per day) and reducing the overall prevalence of the infection in the population. All persons living in a district in Zanzibar were tested for S. haematobium infection, and chemotherapy was given to those found to be infected. Testing took place four different times between August 1981 and August 1983. On the first date, 2,685 people were tested, of whom 1,324 (49.3 percent) were positive; 518 (19.3 percent) of these patients had heavy infections. On the second date, 1,887 persons were tested, of whom 1,420 had been tested the prior year. Overall, 751 (39.8 percent) were infected, and 245 (13.5 percent) had heavy infections On the third date, 2,458 persons were tested, of whom 1,342 had been tested on the second date. Of those tested, 848 (34.5 percent) were positive and 269 (10.9 percent) were heavily infected. On the final date, 1,719 persons were tested; 1,416 had been tested before. Of those tested, 398 (23.2 percent) were infected and 126 (7.3 percent) were heavily infected. Overall, the prevalence rate of infection was reduced 52.9 percent and that of heavy infection was reduced 62.2 percent. Between 55 and 65 percent of persons who tested positive on each date took all three doses of the drug. The results indicated that mass testing and use of metrifonate for those who test positive reduces the prevalence of S. haematobium infection. (Consumer Summary produced by Reliance Medical Information, Inc.), Introduction Advances in diagnostic techniques and chemotherapy now ensure that reduction in disease due to schistosomiasis is within the capabilities of the current health infrastructures of many endemic countries [1]. [...]

Urban development and the health of urban populations are directly related. As rural populations migrate into urban areas, they bring with them rural parasitic diseases. Inadequate urban development results in high population densities in areas with poor sanitation and inadequate water supply mechanisms. This can directly affect the extent and severity to which the newly introduced parasitic diseases will infect the population. Chagas disease, filariasis, leishmaniasis, and schistosomiasis are examples of parasitic diseases that originate in rural populations, but are now infecting urban populations. There are six possible scenarios underlying the interactions between the introduction and the epidemiology of rural parasitic disease in urban populations. The first means is when an infected person enters a nonendemic urban area without vectors (modes of transmission such as organisms); careful screening of donated blood can greatly reduce the risk of introducing disease into the urban population. The second scenario is like the first except that vectors are present; proper sanitation and a clean food and water supply are the best preventative methods in this case. When an infected person enters an area in which the disease is already present, the person contributes to the direct spread of the disease. When non-infected persons enter an infected area, they may become infected and suffer a more serious bout of infection. In some cases, it is the population that moves into the infected area. A final scenario is the introduction of a new vector into an urban area. The introduction of a disease into an urban population by any of these processes can have severe adverse effects on the health and the economy of the population. Vector control, urban environment analysis, and the health of the individuals must be addressed to prevent the spread of parasitic diseases in urban areas. (Consumer Summary produced by Reliance Medical Information, Inc.), Introduction Urban development, a process related to economic and political factors, has a direct bearing on the health of urban populations. (a) Social phenomena such as rural-to-urban migration and job [...]