Energy expenditure of agricultural workers in an area of endemic schistosomiasis in the Sudan

Indices of physiological performance in the field under natural working conditions were measured in 46 Sudanese Gezira villagers and related to exercise performance under controlled laboratory conditions. The effect of Schistosoma mansoni infection on energy expenditure in the field was also investigated. A highly significant positive association between the maximal aerobic power output (VO2 max) measured in the laboratory with energy expenditure in the field (r = + 0.51, p less than 0.001) and with changes in body weight during work (r = 0.41, p less than 0.01) was found. The villagers' energy expenditure in field work amounted to 25-28 KJ/min, which corresponded to more than 50% of their predicted VO2 max. They maintained that relative work level for more than an hour. The differences in energy expenditure between moderately infected and non-infected villagers with schistosomiasis did not attain statistical significance but the number of non-infected subjects on which the comparison was based was small.     

Migrant workers and schistosomiasis in the Gezira,Sudan

A cross sectional study of schistosomiasis in migrant labourers in the Sudan Gezira is described. The people examined were of two ethnic groups: (i) those of local Arabic origin and (ii) those from Western Sudan, West Africa or west of longitude 27 °E. These two migrant groups were examined in one area treated with molluscicide and in another that was not. Almost all the schistosome infections were with Schistosoma mansoni, with a prevalence of 57% over-all and up to 89% in particular groups. The prevalence was lower in the treated than in the untreated area, and slightly lower in the Arab nomads than in the others, except that it was markedly lower in females from the West in the treated area. These results are consistent with the known water-contact habits of the two migrant groups. An association was observed between infection and liver and spleen enlargement, but not between infection and other symptoms. The potential importance of migrants in transmitting the infection is discussed.     

The energy expenditure of Iranian agricultural workers.

The energy cost of agricultural and standard activities and the daily energy expenditure of male agricultural workers were measured during different seasons in Iranian villages to assess the validity of past and present Food and Agricultural Organization recommended energy allowances for that population. Studies included low income farmers in a village representative of those around the central desert where harvesting takes place under conditions of extreme summer heat. Measurements were also made during the Moslem fasting period when no food may be eaten between dawn and dusk. Energy cost of typical activities was measured by indirect calorimetry using the Max-Planck respirometer and daily energy expenditure was assessed using these figures combined with a diary of activities throughout the 24-hr period. Results of individual activity values are compared with other published figures. Comparison of daily energy expenditure of fasting subjects and nonfasting after Ramazan showed no significant difference. No significant difference was found between values of standardized activities at high summer temperatures and moderate temperatures. Mean values of daily energy expenditure during winter when activity is low are around 2600 kcal/day and for the other seasons of high activity 3400 kcal/day. These figures suggest that past and present Food and Agricultural Organization standards are low for this population.     

Clinical recognition of mild hepatic schistosomiasis in an endemic area

From this comparison of 37 black children with hepatic schistosomiasis (HS) and 53 with intestinal Schistosoma mansoni (IS) living in an endemic area, we propose easily identifiable clinical features of mild HS. These patients were generally well nourished school-age children who seldom complained of dysentery but who had a firm hepatomegaly with predominant enlargement of the left lobe and a firm splenomegaly. They were also mildly anaemic (9.4 +/- 2.2 g/dl) and had low serum albumin (30 +/- 7 g/l), raised aspartate transaminase (36 +/- 31 u/l) and high globulins (53 +/- 15 g/l). The implications of the absence of severe hepatosplenic schistosomiasis in many of these children are discussed.     

Epidemiology of schistosomiasis mansoni in a low endemic area

We discuss the epidemiological patterns of schistosomiasis mansoni in areas with low transmission in Brazil. We define as areas of low endemicity those where the prevalence is less than 10%, the number Schistosoma mansoni eggs per gram of feces (epg) is less than 96, and carriers are asymptomatic. Data are from the county of Pedro de Toledo in the Ribeira Valley (S?o Paulo State) and were collected randomly according to the aggregate pattern of S. mansoni within the hosts. We suggest the replacement of parasitological methods by more sensitive and specific serological techniques. The main risk factor for infection is type of leisure activity. Infection is more frequent in the 10-14, 15-19, and 20-24-year age brackets. Geometric mean epg is 58.5. Intensity of infections correlates well (rs = 0.745) with prevalence. The highest index of potential contamination is in the 5-20-year age bracket (57.6%). Autochthonous cases show close association with Biomphalaria tenagophila, which has a low infection rate (2%). Prevalence, incidence, and intensity of infection patterns are similar to those of moderate and high endemic areas. Social and cultural aspects must be studied in order to obtain a global epidemiological view of schistosomiasis.     

Water-contact patterns and socioeconomic variables in the epidemiology of schistosomiasis mansoni in an endemic area in Brazil

A study was carried out in Comercinho in south-east Brazil where information relating to socioeconomic factors and water contacts was obtained from 290 (99% of the total) households and 1208 (82% of the total) inhabitants, respectively. Stool examinations and physical examinations were performed on 90% and 82% of the population, respectively. The rates of Schistosoma mansoni infection and splenomegaly were higher in families whose heads were manual workers, in individuals living in houses without piped water and of poor construction, and in those who were born in Comercinho. A total of 1017 (84%) individuals reported water contact; 75% of these contacts were for household activities or bathing and 21% for leisure. The faecal egg counts decreased in persons over 15 years of age, while the degree (intensity) of water contact did not. The mean degree of water contact was higher in individuals without than with piped water in the household (96.8±0.6 v. 25.7±0.6). The main risk factors for splenomegaly weer no piped water, intense water contact, bathing in streams, and daily contact (odds ratio=7.3, 5.1, 4.5 and 3.6, respectively). These results indicate that the extension of piped water to houses should decrease the incidence of splenomegaly in this endemic area.     

Socio-cultural and nutritional risk factors of adolescents and young pregnant women in an endemic area of schistosomiasis.

The present study was undertaken in order to investigate the social, cultural, behavioral and environmental factors and their impact on the health and nutrition of young pregnant women and adolescent girls aged between 11 and 22 years, living in a rural area known to be endemic of schistosomiasis. A total sample of 34 pregnant women, 30 adolescent girls and 5 married never-pregnant women were recruited initially. The results revealed that early marriage before legal age still occur in rural areas in Egypt (15%). The mean age of marriage was 17.5 years (+/- 1.8) while the mean age at the first conception was 17.9 years (+/- 1.6). A high rate of illiteracy (72%) which was statistically significant was found among married women than adolescent girls. The daily intake of most nutrients were below the RDA except for protein and vitamin C among pregnant respondents. Iron, calcium and riboflavin were the nutrients most poorly supplied by the diets of pregnant women and adolescent girls. A significant statistical difference was found between the two groups in the intake of iron (z = 3.20, p < 0.05). About 60% of pregnant women and 80% of adolescent girls reported contact with canal water during household activities and field work. There was a lack of knowledge as regards schistosomiasis among respondents especially pregnant ones. Home deliveries with the assistance of traditional birth attendants is still the first choice by most of the pregnant respondents.     

血吸虫病轻疫区用改良加藤厚涂片法考核疫情效果分析

改良加藤法(Kato-Katz法)自20世纪80年代初期被引进国内用于血吸虫病病原学诊断,经大量实验室与现场研究,公认该法作血吸虫病流行病学调查居民感染率具有加样量衡定,操作简便,受环境因素影响小,成本低和效果较满意等优点。上个世纪90年代始,Kato-Katz厚涂片法已被我国定为血吸虫病病原学检查的基本方法之一〔1〕,推广应用。为考核武汉市血吸虫病疫情,2007年10~11月湖北省血吸虫病防治研究所与武汉市血吸虫病防治研究所采用Kato-Katz厚涂片法对武汉市5个疫区进行随机抽样调查,现将调查结果报道如下。1资料与方法1.1样本村抽样采用分层随机…     

湖北省血吸虫病疫区农村户厕粪便无害化监测报告

目的评估湖北省血吸虫病疫区农村户厕粪便无害化方法及效果。方法选择血吸虫病疫区乡镇6个行政村,随机抽查180座农村户厕,勘测记录农村户厕建筑结构,详细调查卫生状况和户厕使用情况。结果采用沼气式和三格式户厕建筑设计的农户与非卫生户厕建筑设计卫生学指标比较有显著性差异。结论湖北省血吸虫病疫区农村户厕建筑经粪便无害化设计处理后,能改善卫生状况,降低疾病传播的风险。     

The interdiction of disease: a cultural construction of schistosomiasis in an endemic area in Minas Gerais,Brazil

This study was conducted in a rural area endemic for schistosomiasis in Minas Gerais, Brazil. The objective was to determine the relationship between an environmental and health education program for schistosomiasis, implemented for teachers and students from the state secondary school in the village of Boa Uni?o, and the subsequent actions of its participants in regards to the environment and the illness. An important difference in this program is its perspective that it is not merely the implementation of instrumental and cognitive knowledge of the environment and illness, but an approach in which subjects are asked to question and investigate their perception of reality, the environment, and the illness. The study demonstrated that a change in attitude could occur from reflection on one's experience in relation to both the environment and diseases endemic it.     

Epidemiological aspects of intraocular pressure in an onchocerciasis endemic area.

A field investigation of intraocular pressure in populations in onchocerciasis endemic areas of West Africa revealed a normal pressure distribution in individuals without signs of ocular onchocerciasis or with only microfilariae or reversible lesions in the eye. Females showed a significantly higher mean ocular tension, and in both sexes tension decreased with age. Patients with irreversible onchocercal ocular lesions and signs of anterior uveitis showed a significantly lower and abnormally distributed intraocular pressure. The prevalence of glaucoma was significantly higher in this group, thus indicating that a high intensity of onchocercal infection may be associated with a risk of secondary glaucoma. The presence of microfilariae in the ocular tissues and consequent inflammatory reactions may possibly give rise to an abnormal distribution of ocular tension.     

Socioeconomic determinants of schistosomiasis in an urban area in the Northeast of Brazil.

OBJECTIVE: To identify and quantify the socioeconomic determinants of schistosomiasis in the urban section of S?o Louren?o da Mata, a town in the Northeast of Brazil. METHODS: A cross-sectional study was carried out in 1988 to measure the prevalence of schistosomiasis in S?o Louren?o da Mata among individuals aged 10-25 years and to estimate the socioeconomic characteristics of the households of those individuals. Household aggregation was tested. The data were analyzed on two levels, the family level and the individual level. On the family level we estimated the odds ratios for the association of schistosomiasis and socioeconomic variables related either to the head of the family or to the household. On the individual level we investigated if for the infected individuals there were differences in the intensity of infection (mean egg count) for the different levels of the socioeconomic variables. RESULTS: We found a significant degree of household aggregation of schistosomiasis (allowing for sex and area of residence (neighborhoods with similar socioeconomic conditions, according to census data)). In the analysis on the family level, better socioeconomic indicators for the place in the productive process (occupation, economic sector, and position in production of the head of the family, plus family income) and better socioeconomic indicators for patterns of consumption (level of education of the head of the family, type of housing, household possessions, water supply for the home, sanitation (that is, excreta collection), and family access to medical care) were all associated with a lower risk of schistosomiasis. The estimation of the probability of schistosomiasis for different levels of the socioeconomic variables showed a lower risk (0.072) for individuals whose households were at the top (best) levels of the indicators relative to the risk (0.715) for individuals whose households were at the baseline (lowest) levels of the indicators. Infected individuals whose families had better socioeconomic conditions had lower mean egg count values. CONCLUSIONS: Control measures that may have a long-term effect, such as improvements in the water supply and sanitation, should be strongly encouraged. The theoretical reduction that we found in the probability of being infected if water supply and sanitation were improved highlights the importance of these measures. Implementing them would have a more permanent effect on the control of schistosomiasis and would also result in other benefits to the population.