Investigations into the free-living phase of the cat hookworm life cycle

Nwosu, A. B. C.

doi:10.1007/bf00931717

Cited by 9 publications

(7 citation statements)

References 13 publications

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“…Relationship between temperature (a) parasite survival and (b) development duration. Points indicate experimental data (Seamster, 1950; Beer, 1973; Nwosu, 1978; Udonsi & Atata, 1987) and lines are fits derived from fractional polynomials analyses. Regression details: parasite survival y = 0.884 + −22.88 x −0.5 + −7.73ln( x ); A. lumbricoides duration y = 8.601 + −63.718 x − −2 + 2.526 x −3 ; T. trichiura duration y = 26.079 + 41209.68 x −−2 + −1715.02 x —2 ; hookworm duration y = 3.701 + 40.88 x −−2 + −46.18 x −−2 …”

Section: Figurementioning

confidence: 99%

“… † Data taken from Anderson (1982); Bundy & Cooper (1989); Crompton (2001) ‡ Data taken from Anderson & May (1991) § Data on A. lumbricoides (Seamster (1950); T. suis (Beer, 1976); hookworm (Nwosu, 1978; Smith & Schad, 1989). …”

Section: Figurementioning

confidence: 99%

“… § Data on A. lumbricoides (Seamster (1950); T. suis (Beer, 1976); hookworm (Nwosu, 1978; Smith & Schad, 1989). …”

Section: Figurementioning

confidence: 99%

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Global Epidemiology, Ecology and Control of Soil-Transmitted Helminth Infections

Brooker

Clements

Bundy

2006

Advances in Parasitology

584

519

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Soil-transmitted helminth (STH) infections are among the most prevalent of chronic human infections worldwide. Based on the demonstrable impact on child development, there is a global commitment to finance and implement control strategies with a focus on school-based chemotherapy programmes. The major obstacle to the implementation of cost-effective control is the lack of accurate descriptions of the geographical distribution of infection. In recent years considerable progress has been made in the use of geographical information systems (GIS) and remote sensing (RS) to better understand helminth ecology and epidemiology, and to develop low cost ways to identify target populations for treatment. This chapter explores how this information has been used practically to guide large-scale control programmes. The use of satellite-derived environmental data has yielded new insights into the ecology of infection at a geographical scale that has proven impossible to address using more traditional approaches, and has in turn allowed spatial distributions of infection prevalence to be predicted robustly by statistical approaches. GIS/ RS have increasingly been used in the context of large-scale helminth control programmes, including not only STH infections but also those focusing on schistosomiasis, filariasis and onchocerciasis. The experience indicates that GIS/RS provides a cost-effective approach to designing and monitoring programs at realistic scale. Importantly, the use of this approach has begun to transition from being a specialist approach of international vertical programs to become a routine tool in developing public sector control programs. GIS/RS is used here to describe the global distribution of STH infections and to estimate the number of infections in school age children in sub-Saharan Africa (89.9 million) and the annual cost of providing a single anthelmintic treatment using a school-based approach (US$5.0-7.6 million). These are the first estimates at a continental scale to explicitly include the fine spatial distribution of infection prevalence and population, and suggest that traditional methods have overestimated the situation. The results suggest that continent-wide control of parasites is, from a financial perspective, an attainable goal.

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Section: Figurementioning

confidence: 99%

Section: Figurementioning

confidence: 99%

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Global Epidemiology, Ecology and Control of Soil-Transmitted Helminth Infections

Brooker

Clements

Bundy

2006

Advances in Parasitology

584

519

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“…Chandler concluded that 20-30 °C was optimal for transmission with larvae reaching maturity in five days, with the lower limit lying between 8-10 °C and the upper limit 40-45 °C. Available experimental data indicate that above temperatures of 35-40 °C development of eggs arrests and death occurs (Nwosu, 1978; Udonsi and Atata, 1987; Smith and Schad, 1990). For example, Udonsi and Atata (1987) showed that at temperatures of 35 °C larvae of Necator americanus were all dead, with the highest cumulative hatching rates obtained at 30 °C.…”

Section: Epidemiology and Transmission Dynamicsmentioning

confidence: 99%

Human Hookworm Infection in the 21st Century

Brooker¹,

Bethony²,

Hotez³

2004

Advances in Parasitology

360

329

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The scientific study of human hookworm infection began at the dawn of the twentieth century. In recent years, there have been dramatic improvements in our understanding of many aspects of this globally widespread parasite. This article reviews recent advances in our understanding in the biology, immunology, epidemiology, public health significance and control of hookworm, and to look forward to the study of this important parasite in the 21 st century. Advances in molecular biology has lead to the identification of a variety of new molecules from hookworms, which have importance either in the molecular pathogenesis of hookworm infection or in the host-parasite relationship; some are also promising vaccine targets. At present, relatively little is known about the immune responses to hookworm infection, although it has recently been speculated that hookworm and other helminths may modulate specific immune responses to other pathogens and vaccines. Our epidemiological understanding of hookworm has improved through the development of mathematical models of transmission dynamics, which coupled with decades of field research across mutliple epidemiological settings, have shown that certain population characteristics can now be recognised as common to the epidemiology, population biology and control of hookworm and other helminth species. Recent recognition of the subtle, but significant, impact of hookworm on health and education, together with the simplicity, safety, low cost, and efficacy of chemotherapy has spurred international efforts to control the morbidity due to infection. Large-scale treatment programmes are currently underway, supported by health education and integrated with the provision of improved water and sanitation. There are also efforts underway to develop novel anthelmintic drugs and anti-hookworm vaccines.

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“…(CLARKE & PERRY, 1977) has been studied as the first stage in the infection process, rather less attention has been paid to the eggs of those nematodes that hatch spontaneously. Much of the work that has been done has concentrated on over-all development times from egg release in the faeces to development of infective third-stage larvae (BELLE, 1959;GIBBS & GIBBS, 1959;PRASAD, 1959;SILVERMAN & CAMPBELL, 1959;PANDEY, 1972, Nwosu, 1978. However, WILSON (1958) using Trichostrongylus retortaeformis, CROLL (1974) with Necator americanus and VINA YAK et al (1978) with Ancylostoma duodenale looked directly at egg development and emergence of the first-stage larvae.…”

Section: Introductionmentioning

confidence: 99%

The influence of temperature and osmotic stress on the development and eclosion of hookworm eggs

Matthews

1985

J. Helminthol.

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Time lapse video micro recording techniques have been used to investigate the development and eclosion of Ancylostoma ceylanicum and A. tubaeforme eggs under a range of temperature and osmotic conditions. Over the range 15 to 35°C increasing temperature resulted in decreased development time, the hyperbolic form of the curve being similar to that found by other workers. The adoption of a developmental parameter to mark the start of timing provided more reproducible results than previously reported. Osmotic stress in the range 0·600 mOsM/kg provided by a number of inorganic salts and organic sugars increased hatching time but did not greatly reduce the percentage that hatched. There was no correlation between the ionic composition of the solution and its effect on the eggs. Solutions of EDTA, carbonates and iodides markedly reduced hatching. Behavioural studies of the pre-hatched larvae suggested that the eggs were permeable and susceptible to osmotic and ionic changes early in their development and well before they were ready to hatch. No appreciable differences were found between the two species of hookworm investigated.

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Investigations into the free-living phase of the cat hookworm life cycle

Cited by 9 publications

References 13 publications

Global Epidemiology, Ecology and Control of Soil-Transmitted Helminth Infections

Global Epidemiology, Ecology and Control of Soil-Transmitted Helminth Infections

Human Hookworm Infection in the 21st Century

The influence of temperature and osmotic stress on the development and eclosion of hookworm eggs

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