No description available.

No description available.

The intensity and prevalence of infection with T. tenuis adults and larval stages is described for eight populations of red grouse in northern England and Scotland. During winter most larvae were present as arrested exsheathed third stage larvae. Arrested larval burdens were positively correlated with adult worm counts but the predictive value of this relationship was poor. Numbers of arrested larvae varied widely amongst locations and were weakly correlated with grouse density and maximum autumn temperatures. Exposure of infective larvae to low temperatures for 4-12 weeks before infection of captive grouse failed to induce substantial numbers to arrest. The highest numbers of inhibited larvae were observed in grouse given chilled L3 from a worm population known to exhibit high levels of arrest in wild grouse. Larval stages not usually associated with arrested development also occurred well after the usual prepatent period. Developing larvae and adult worms present at the onset of laying in hen grouse did not significantly reduce egg production. However, developing worms caused hen grouse to lose significantly more body weight during laying. Hen grouse may have retained the ability to lay despite infection, at the cost of investment in reserves for incubation. Developing larvae caused a severe energy imbalance in captive grouse at 12-16 dpi as late 4th-stage larvae developed into adult worms. At 12 dpi infected birds had significantly elevated resting metabolic rates and at 16 dpi voluntary food intake was significantly depressed relative to controls. After this, effects on energy balance diminished but there followed a gradual reduction in grouse body weight and condition. The resumed development of arrested larvae in wild grouse in spring presumably has similar effects and could reduce their fecundity and survival.

No description available.

No description available.

This transnational study of the first-wave South Asian immigrant experience in British Columbia and the Pacific coast states shows how elected officials at all levels of government, bureaucrats, union leaders, physicians, members of the press, and the general public utilized purported public health concerns to justify South Asian exclusion and disenfranchisement. While all Asian groups living along the Pacific coast faced opposition to their immigration and settlement, India’s subordinate status within the British Empire, and a sustained western association of South Asians with disease, uniquely positioned North American discourse on South Asians at the intersection of colonial theory, Orientalism, and medicalized nativism in the first two decades of the twentieth century. / Thesis (Ph.D, History) -- Queen's University, 2013-09-25 20:19:03.29

Hookworm infection caused by Ancylostoma duodenale or Necator americanus is a significant global health threat, causing chronic anemia, malnutrition, developmental delay, enteritis, and increased susceptibility to non-parasitic diseases. One of the most prevalent of the neglected tropical diseases, hookworm infection affects almost 1 billion people worldwide, particularly in developing countries. Current methods for diagnosis and treatment of hookworm infection are largely the same as they have been for the past century. However, several recent advances in the molecular characterization of hookworm virulence factors now provide researchers with an improved understanding of disease pathogenesis, potential targets for treatment and novel antigens for vaccine development. In order to better understand hookworm pathophysiology and immunology in human populations, a comprehensive, cross-sectional immunoepidemiologic survey of approximately 200 villagers in a remote area of the Peruvian Amazon was conducted. Hookworm prevalence rates were found to approach 40% by microscopic diagnosis. Additionally, molecular speciation techniques showed that both A. duodenale and N. americanus are endemic to this region. Reagents from a laboratory model of hookworm disease were then utilized to characterize human immune responses to hookworm specific antigens. By studying the immunoepidemiology of an endemic community we have found that a laboratory strain of hookworm, Anyclostoma ceylanicum, is a useful tool for describing species specific immune responses to disease. This work lays the foundation for future development of improved hookworm diagnostic techniques by molecular and immunologic methods.

No description available.

Thesis (M.P.H.M. (Primary Health Care Management))--Mahidol University, 2000.

Background: Soil transmitted helminth infections (STHI) are important Neglected Tropical Diseases (NTD). The three main STHI are infections with Ascaris lumbricoides, Trichuris trichiura and hookworms. STHI have a significant effect on the growth and development of children. A national survey for STHI in El Salvador by Pan American Health Organization and Ministry of Health in 2012 in school children aged 8years to 10 years. The survey collected data on age, gender, behavioral habits, and source of drinking water, type of toilet facility used and ecological zone of residence. A) We did an analyses of the data with an aim to determine the prevalence of STHI in El Salvador, assess the risk factors and risk interactions. B) We also aimed to determine the efficacy of urea as a potential additive for inactivation of Ascaris suum in solar toilets. Methods: A) Data from 1310 subjects was analysed for determination of prevalence of STHI in El Salvador. Risk factor assessment was done by chi-square test, unadjusted logistic regression and fully adjusted logistic regression. Risk factor interactions was tested on multiplicative and additive scale. B) Urea was tested for efficacy in inactivation of Ascaris suum ova in 20 solar toilets. Under conditions of controlled pH and moisture, concentration of gas ammonia, peak temperature were measured along with duration of treatment with urea to determine viability of Ascaris suum samples placed in the solar toilets. Results: I) The prevalence of Ascaris lumbricoides in 8-10 year old school children is 2.75%, Trichuris trichiura is 4.1% and hookworm is 1.83%. A) For Ascaris lumbricoides infection: Significant risk in individuals from volcanic chains and central depression compared to those from the mountains. Spring or well water when used as source of drinking water was associated with higher risk of infection when compared with piped water. Higher infection was also associated with open air defecation compared to use of septic tank or flush toilet. Use of sandals or no footwear was associated with a higher risk of infection when compared to use of closed footwear at all times. B) For Trichuris infection: Coastal plains were associated with a higher risk of infection compared to the mountains while rural status was protective against infection. Spring or well water when used as source of drinking water was associated with higher risk of infection when compared with piped water. Use of sandals or no footwear was associated with a higher risk of infection when compared to use of closed footwear at all times. C) For hookworm infection: Risk of infection was higher in individuals from urban regions. Spring or well water when used as source of drinking water was associated with higher risk of infection when compared with piped water. Use of sandals or no footwear was associated with a higher risk of infection when compared to use of closed footwear at all times. Poor handwashing was shown to be protective against infection with hookworm. Significant risk factor interactions were identified for infection with each of the three soil transmitted helminths. II) Urea as an additive at 1%w/w to feces tested in solar toilets showed an inactivation rate of nearly half the Ascaris suum ova samples. Fifty percent or higher inactivation rates were associated with ammonia gas concentrations of 109.5 ppm or higher and duration of treatment of 72 hours or higher. Conclusions: Prevalence of STHI in 8-10 year old school children for 2012 in El Salvador is low. Significant risk factors for STHI in El Salvador are eco-epidemiologic zone, source of drinking water, type of sanitation, use of shoes behavior and urban status of place of residence. Use of urea for inactivation of soil transmitted helminth ova in feces is a possible intervention for environmental control of STHI.