Biomedical subjects

Adrian C Sleigh

Publications and source records attributed to Adrian C Sleigh.

10 recordsLinked to original sources

PubMed2006

A drug-based intervention study on the importance of buffaloes for human Schistosoma japonicum infection around Poyang Lake, People's Republic of China.

Schistosomiasis japonica is a zoonosis of major public health importance in southern China. We undertook a drug intervention to test the hypothesis that buffalo are major reservoirs for human infection in the marshlands/lake areas, where one million people are infected. We compared human and buffalo infection rates and intensity in an intervention village (Jishan), where humans and buffalo were treated with praziquantel, and a control village (Hexi), where only humans were treated, in the Poyang Lake region. Over the four-year study, human incidence in Jishan decreased but increased in Hexi. Adjustment of incidence by age, sex, water exposure, year, and village further confirmed the decreased human infection in Jishan. Chemotherapy for buffaloes resulted in a decrease in buffalo infection rates in Jishan, which coincided with the reduction in human infection rates there in the last two years of the study. Mathematical modeling predicted that buffalo are responsible for 75% of human transmission in Jishan.

Adolescent↗

PubMed2005

Parental occupation and Ewing's sarcoma: pooled and meta-analysis.

Etiologic data on Ewing's sarcoma family of tumors (ESFT) are limited, with only 5 case-control studies reported. Interesting associations, particularly related to parental occupation, have been noted, but results are somewhat inconsistent. We conducted a pooled analysis of 3 case-control studies to assess the overall associations between parental occupation and ESFT. The pooled analysis provided data on parental occupational exposure on 199 cases of ESFT and 1,451 controls. The pooled odds ratio for the periconception and gestation periods were 2.3 (95% CI = 1.3-4.1) for children whose fathers had worked on farms and 3.9 (95% CI = 1.6-9.9) for those whose mothers had farmed. For the periconception and gestation periods, there was a 3.5-fold increased risk for those with both parents having farmed and a doubling of risk for those with at least one parent having farmed; pattern of increasing risk with increasing number of years of postnatal parental exposure to farms was seen. No other occupational group (or more narrowly defined occupations) had other than minor inconsistent associations with the occurrence of ESFT. In addition, we conducted a meta-analysis of farm occupation (a main risk factor) including all 4 case-control studies that collected required information to consider parental occupation. Results of the meta-analysis were consistent with those from the pooled analysis. This collaborative analysis of available individual data on parental occupation and ESFT in the offspring provides evidence supporting the hypothesis of an association between ESFT and parental occupation in farming.

Adolescent↗

PubMed2005

Risks for Ross River virus disease in tropical Australia.

BACKGROUND: There are no analytical studies of individual risks for Ross River virus (RRV) disease. Therefore, we set out to determine individual risk and protective factors for RRV disease in a high incidence area and to assess the utility of the case-control design applied for this purpose to an arbovirus disease. METHODS: We used a prospective matched case-control study of new community cases of RRV disease in the local government areas of Cairns, Mareeba, Douglas, and Atherton, in tropical Queensland, from January 1 to May 31, 1998. RESULTS: Protective measures against mosquitoes reduced the risk for disease. Mosquito coils, repellents, and citronella candles each decreased risk by at least 2-fold, with a dose-response for the number of protective measures used. Light-coloured clothing decreased risk 3-fold. Camping increased the risk 8-fold. CONCLUSIONS: These risks were substantial and statistically significant, and provide a basis for educational programs on individual protection against RRV disease in Australia. Our study demonstrates the utility of the case-control method for investigating arbovirus risks. Such a risk analysis has not been done before for RRV infection, and is infrequently reported for other arbovirus infections.

Adolescent↗

PubMed2005

Hernias and Ewing's sarcoma family of tumours: a pooled analysis and meta-analysis.

BACKGROUND: Ewing's sarcoma family of tumours has been associated with a history of hernia and with a parental occupation of farming. However, the causes of these tumours remain unknown. We therefore aimed to investigate the association between hernia and Ewing's sarcoma family of tumours. METHODS: We did a pooled analysis of two case-control studies and a meta-analysis of three case-control studies of Ewing's sarcoma family of tumours that had adequate information on history of hernia. The primary endpoint was development of a tumour from the Ewing's sarcoma family. 138 patients with such a tumour and 574 controls were included in the pooled analysis, and 357 patients with these tumours and 745 controls were included in the meta-analysis. Risk was assessed by an odds ratio (OR) and 95% CI by use of multivariate analysis with unconditional logistic regression for the pooled analysis and random effects model for the meta-analysis. FINDINGS: Pooled analysis showed that children with Ewing's sarcoma family of tumours were more likely to have had an umbilical hernia than were controls (odds ratio [OR] 3.3 [95% CI 1.3-8.0]). Meta-analysis showed that children with Ewing's sarcoma family of tumours were more likely to have had a hernia (3.2 [1.9-5.7]). INTERPRETATION: Ewing's sarcoma family of tumours and hernias (particularly inguinal hernias) have common embryological pathways of neuroectodermal origin, and environmental factors, such as farming, might link the two entities.

Adolescent↗

PubMed2005

Impact of parasitic infections and dietary intake on child growth in the schistosomiasis-endemic Dongting Lake Region, China.

The simultaneous impacts of parasitic infections and dietary intake on growth patterns were investigated for 427 children aged 10-13 years in the schistosomiasis-endemic Dongting Lake region of China. Height, weight, mid-upper arm circumference, and skinfold thicknesses (triceps, biceps, and subscapular) were measured, and eggs of Schistosoma japonicum, Ascaris lumbricoides, Trichuris trichiura, and Fasciolopsis buski in the collected stool samples of each subject were detected by Kato-Katz thick smear technique. Long-term dietary intake of each subject was assessed with a semiquantitative food frequency questionnaire. The results demonstrate that the study children were retarded in growth compared with the standards of Chinese rural children; among them, the girls were more frequently infected for S. japonicum and had lower intakes of protein and energy. Reduced height, weight, and mid-upper arm circumference were noted in children infected with S. japonicum, most severely in the girls with the least energy and protein intakes. Multiple stepwise regression analysis indicated that growth retardation was significantly and substantially associated with S. japonicum infection and lack of protein-energy intakes. For child health programs, regular schistosomiasis screening and treatment in schoolchildren needs to be complemented by health and nutrition education for both children and parents. Also, special attention should be paid to educating parents about the needs of girls.

Adolescent↗

PubMed2004

Predicting super spreading events during the 2003 severe acute respiratory syndrome epidemics in Hong Kong and Singapore.

One of the intriguing characteristics of the 2003 severe acute respiratory syndrome (SARS) epidemics was the occurrence of super spreading events (SSEs). Here, the authors report the results of identifying the occurrence of SSEs in the Hong Kong and Singapore epidemics using mathematical and statistical analysis. Their predicted occurrence of SSEs agreed well with the reported occurrence of all seven super spreaders in the two cities. Additional unidentified SSEs were also found to exist. It was found that 71.1% and 74.8% of the infections were attributable to SSEs in Hong Kong and Singapore, respectively. There also seemed to be "synchronized" occurrences of infection peaks in both the community and the hospitals in Hong Kong. The results strongly suggested that the infection did not depend on the total number of symptomatic cases, with only a very small proportion of symptomatic individuals being shown to be infectious (i.e., able to infect other individuals). The authors found that the daily infection rate did not correlate with the daily total number of symptomatic cases but with the daily number of symptomatic cases who were not admitted to a hospital within 4 days of the onset of symptoms.

Adult↗

PubMed2002

Ross River virus disease in tropical Queensland: evolution of rheumatic manifestations in an inception cohort followed for six months.

OBJECTIVE: To describe the natural history of rheumatic manifestations of Ross River virus (RRV) disease. DESIGN: Prospective longitudinal clinical review. SETTING: North Queensland local government areas of Cairns, Douglas, Mareeba and Atherton during January to May 1998. PARTICIPANTS: General practice patients diagnosed with RRV disease on the basis of symptoms and a positive RRV IgM result. MAIN OUTCOME MEASURES: Rheumatic symptoms and signs assessed as soon as possible after disease onset and on two subsequent occasions (up to 6.5 months after onset). RESULTS: 57 patients were recruited, 47 of whom were reviewed three times (at means of 1.1, 2.4 and 3.6 months after disease onset). Results are reported for these 47: 46 (98%) complained of joint pain at first review, with the ankles, wrists, fingers, knees and metacarpophalangeal joints (II-IV) most commonly involved. Prevalence of joint pain decreased progressively on second and third reviews, both overall (92% and 68% of patients, respectively), and in the five joints most commonly affected. The prevalence of other common rheumatic symptoms and signs, and use of non-steroidal anti-inflammatory drugs, also progressively declined over the three reviews. CONCLUSIONS: Earlier studies may have overestimated the prevalence and duration of symptoms in RRV disease. Progressive resolution over 3-6 months appears usual.

Adult↗

PubMed2002

Cost of malaria control in China: Henan's consolidation programme from community and government perspectives.

OBJECTIVE: To assist with strategic planning for the eradication of malaria in Henan Province, China, which reached the consolidation phase of malaria control in 1992, when only 318 malaria cases were reported. METHODS: We conducted a prospective two-year study of the costs for Henan's malaria control programme. We used a cost model that could also be applied to other malaria programmes in mainland China, and analysed the cost of the three components of Henan's malaria programme: suspected malaria case management, vector surveillance, and population blood surveys. Primary cost data were collected from the government, and data on suspected malaria patients were collected in two malaria counties (population 2 093 100). We enlisted the help of 260 village doctors in six townships or former communes (population 247 762), and studied all 12 325 reported cases of suspected malaria in their catchment areas in 1994 and 1995. FINDINGS: The average annual government investment in malaria control was estimated to be US$ 111 516 (case-management 59%; active blood surveys 25%; vector surveillance 12%; and contingencies and special projects 4%). The average cost (direct and indirect) for patients seeking treatment for suspected malaria was US$ 3.48, equivalent to 10 days' income for rural residents. Each suspected malaria case cost the government an average of US$ 0.78. CONCLUSION: Further cuts in government funding will increase future costs when epidemic malaria returns; investment in malaria control should therefore continue at least at current levels of US$ 0.03 per person at risk.

Animals↗

PubMed2002

Schistosomiasis.

Explore the source record for details and available documents.

Animals↗

PubMed2002

Mathematical modelling of schistosomiasis japonica: comparison of control strategies in the People's Republic of China.

We present the first mathematical model on the transmission dynamics of Schistosoma japonicum. The work extends Barbour's classic model of schistosome transmission. It allows for the mammalian host heterogeneity characteristic of the S. japonicum life cycle, and solves the problem of under-specification of Barbour's model by the use of Chinese data we are collecting on human-bovine transmission in the Poyang Lake area of Jiangxi Province in China. The model predicts that in the lake/marshland areas of the Yangtze River basin: (1) once-yearly mass chemotherapy of humans is little better than twice-yearly mass chemotherapy in reducing human prevalence. Depending on the heterogeneity of prevalence within the population, targeted treatment of high prevalence groups, with lower overall coverage, can be more effective than mass treatment with higher overall coverage. Treatment confers a short term benefit only, with prevalence rising to endemic levels once chemotherapy programs are stopped; (2) depending on the relative contributions of bovines and humans, bovine treatment can benefit humans almost as much as human treatment. Like human treatment, bovine treatment confers a short-term benefit. A combination of human and bovine treatment will dramatically reduce human prevalence and maintains the reduction for a longer period of time than treatment of a single host, although human prevalence rises once treatment ceases; (3) assuming 75% coverage of bovines, a bovine vaccine which acts on worm fecundity must have about 75% efficacy to reduce the reproduction rate below one and ensure mid-term reduction and long-term elimination of the parasite. Such a vaccination program should be accompanied by an initial period of human treatment to instigate a short-term reduction in prevalence, following which the reduction is enhanced by vaccine effects; (4) if the bovine vaccine is only 45% efficacious (the level of current prototype vaccines) it will lower the endemic prevalence, but will not result in elimination. If it is accompanied by an initial period of human treatment and by a 45% improvement in human sanitation or a 30% reduction in contaminated water contact by humans, elimination is then possible.

Animals↗