full article:Environ Health 2003;2: 1
Contamination of rural surface and ground water by endosulfan in farming areas of the Western Cape, South Africa
Dalvie MA, Cairncross E, Solomon A, London L
Occupational and Environmental Health Research Unit, Department of Public Health, Medical School, University of Cape Town, Anzio Road, Observatory 7925, Cape Town, South Africa. email@example.com
BACKGROUND: In South Africa there is little data on environmental pollution of rural water sources by agrochemicals.
METHODS: This study investigated pesticide contamination of ground and surface water in three intensive agricultural areas in the Western Cape: the Hex River Valley, Grabouw and Piketberg. Monitoring for endosulfan and chlorpyrifos at low levels was conducted as well as screening for other pesticides.
RESULTS: The quantification limit for endosulfan was 0.1 mg/L. Endosulfan was found to be widespread in ground water, surface water and drinking water. The contamination was mostly at low levels, but regularly exceeded the European Drinking Water Standard of 0.1 mg/L. The two most contaminated sites were a sub-surface drain in the Hex River Valley and a dam in Grabouw, with 0.83 PlusMinus; 1.0 mg/L (n = 21) and 3.16 PlusMinus; 3.5 mg/L (n = 13) average endosulfan levels respectively. Other pesticides including chlorpyrifos, azinphos-methyl, fenarimol, iprodione, deltamethrin, penconazole and prothiofos were detected. Endosulfan was most frequently detected in Grabouw (69%) followed by Hex River (46%) and Piketberg (39%). Detections were more frequent in surface water (47%) than in groundwater (32%) and coincided with irrigation, and to a lesser extent, to spraying and trigger rains. Total dietary endosulfan intake calculated from levels found in drinking water did not exceed the Joint WHO/FAO Meeting on Pesticide Residues (JMPR) criteria.
CONCLUSION: The study has shown the need for monitoring of pesticide contamination in surface and groundwater, and the development of drinking water quality standards for specific pesticides in South Africa.
Paediatr Perinat Epidemiol 2003; 17: 125-31
Reliability of maternal recall and reporting of child births and deaths in rural Egypt
Rao MR, Levine RJ, Wasif NK, Clemens JD
Epidemiology Branch, Division of Epidemiology, Statistics and Prevention Research, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA, and UTAS, Assuit, Egypt
Demographic indicators such as fertility rates and infant mortality rates are often measured in census surveys by interviewing mothers to obtain their pregnancy histories and child deaths. The validity of such surveys depends upon accurate recall of histories, truthful reporting of events and understanding of the questions posed. To measure the reliability of maternal reporting, two census surveys conducted in a rural Egyptian population were compared. Women between 15 and 55 years of age residing in 20 villages were asked their histories of live births, stillbirths and child deaths. An identical set of questions was posed 2 years later. Twice-monthly home visits were conducted in the intervening 2-year interval to identify accurately any new births, stillbirths and deaths occurring in the population. The maternal reports from the first census were combined with the prospectively identified births, stillbirths and deaths and compared with the maternal reports from the second census. For 1502 women, the discrepancies in the total number of births, stillbirths and child deaths reported between the two surveys were 0.6%, 4% and 0.6% respectively. However, when the consistency of responses was analysed, the proportion of women with discordant responses was 10%, 6% and 7% for the same measures. These results suggest that, despite the large number of births and deaths that women may experience in developing countries, maternal interviews provide reliable responses that can be used to estimate mortality and fertility rates in settings where vital records are incomplete or unreliable.
J Epidemiol 2003; 13: 80-9
Geographical variation in nutrient intake between urban and rural areas of Jiangsu province, China and development of a semi-quantitative food frequency questionnaire for middle-aged inhabitants
Wang YM, Mo BQ, Takezaki T, Imaeda N, Kimura M, Wang XR, Tajima K
Department of Nutrition and Food Science, Nanjing Medical University
The intake of food and nutrients differs between urban and rural areas in China. To develop a practical semi-quantitative food frequency questionnaire to cover both the urban and rural areas, we conducted diet surveys and compared food and nutrient intake between the two areas. We recruited 198 urban and 214 rural healthy inhabitants aged 35-55 years, and performed diet surveys, using a 3-day weighed dietary record approach. The intake of 29 nutrients was calculated according to actual consumption of foods, with Standard Food Composition Tables for China and Japan. Then, contribution analysis and multiple regression analysis were employed to select food items covering up to a 90% contribution and a 0.90 R2 of coefficient of determination, respectively. Consumption of energy and carbohydrates was greater in the rural area, but mean protein intake was higher in the urban case. Values for total fat were greater for rural than for urban males, with animal fat as the major contributor. We finally selected 117 and 76 food items for the urban and rural semi-quantitative food frequency questionnaires, respectively, covering 18 and 27 nutrients constituting up to 90% of the nutrient intake. Further validity and reproducibility tests are now needed to assess their appropriateness for usage.
Tex Med 2003; 99: 61-5
Kingston BJ, Parchman ML
The association between cotton and prevalence of rural childhood asthma
Department of Family Medicine, Texas Tech University Health Sciences Center at Amarillo, USA. firstname.lastname@example.org
In the United States, asthma now ranks as the most prevalent chronic disease among children. Within rural cotton-producing regions, a popular belief is that cotton production increases the prevalence of asthma. This case-control study was conducted to determine if the prevalence of asthma is higher in children living in rural cotton-producing countries than in children where cotton production is negligible. No evidence was found to support the belief that cotton production increases the rural childhood prevalence of asthma (P = .12). More importantly, this study did reveal a significantly higher prevalence of asthma among the fifth graders in rural West Texas than the prevalence predicted by the Centers for Disease Control and Prevention (P < .0001).
Diabetes Care 2003; 26: 1034-9
Diabetes and impaired fasting glycemia in a rural population of bangladesh
Sayeed MA, Mahtab H, Khanam PA, Latif ZA, Ali SM, Banu A, Ahren B, Azad Khan AK
Department of Epidemiology and Biostatistics, Research Division, BIRDEM, Dhaka, Bangladesh. Institute of Nutrition and Food Science, University of Dhaka, Dhaka, Bangladesh. University of Lundh, Lundh, Sweden
OBJECTIVE: To determine the prevalence of type 2 diabetes and impaired fasting glycemia (IFG) in a rural population of Bangladesh.
RESEARCH DESIGN AND METHODS: A cluster sampling of 4,923 subjects >/=20 years old in a rural community were investigated. Fasting plasma glucose, blood pressure, height, weight, and girth of waist and hip were measured. BMI and waist-to-hip ratio (WHR) were calculated. Total cholesterol, triglycerides, and HDL cholesterol were also estimated. We used the 1997 American Diabetes Association diagnostic criteria. RESULTS: The crude prevalence of type 2 diabetes was 4.3% and IFG was 12.4%. The age-standardized prevalence of type 2 diabetes (95% CI) was 3.8% (3.12-4.49) and IFG was 13.0% (11.76-14.16). The subjects with higher family income had significantly higher prevalence of type 2 diabetes (5.9 vs. 3.5%, P < 0.001) and IFG (15.6 vs. 10.8%, P < 0.001) than those with lower income. Employing logistic regression in different models, we found that wealthy class, family history of diabetes, reduced physical exercise, and increased age, BMI, and WHR were the important predictors of diabetes. Total cholesterol, triglycerides, and HDL cholesterol showed no association with diabetes and IFG.
CONCLUSIONS: The prevalence of diabetes and IFG in the rural population was found to be on the increase compared with the previous reports of Bangladesh and other Asian studies. Older age, higher obesity, higher income, family history of diabetes, and reduced physical activity were proved significant risk factors for diabetes and IFG, whereas plasma lipids showed no association with diabetes and IFG. Further study may address whether diabetes is causally associated with insulin deficiency or insulin resistance.
Acta Trop 2003; 85: 355-361
Relationship between entomological inoculation rate, Plasmodium falciparum prevalence rate, and incidence of malaria attack in rural Gabon
Elissa N, Migot-Nabias F, Luty A, Renaut A, Toure F, Vaillant M, Lawoko M, Yangari P, Mayombo J, Lekoulou F, Tshipamba P, Moukagni R, Millet P, Deloron P
International Center for Medical Research, BP 769, Franceville, Gabon
To assess the relationships between variations of Plasmodium falciparum transmission and those of peripheral parasitaemia prevalence or malaria attack incidence rates in regions with limited fluctuations of transmission, we conducted a follow-up in two Gabonese populations. Entomological surveys were carried out from May 1995 to April 1996 in Dienga, and from May 1998 to April 1999 in Benguia. In Dienga, malaria transmission was seasonal, being not detected during two 3-month periods. Mean entomological inoculation rate (EIR) was 0.28 infective bite/person/night. In Benguia, malaria transmission was perennial with seasonal fluctuations, mean EIR being 0.76 infective bite/person/night. In Dienga, 301 schoolchildren were followed from October 1995 to March 1996. Clinical malaria attack was defined as fever associated with >5000 parasites/ml of blood. P. falciparum prevalence varied from 28 to 42%, and monthly malaria attack incidence from 30 to 169 per thousand. In Benguia, the entire population (122 persons) was followed from November 1998 to April 1999. Prevalence varied from 22 to 50%, and monthly malaria attack incidence from 52 to 179 per thousand. In each area, entomological variations were not related to parasite prevalence, but preceded malaria attack incidence with 1- or 2-month time lag, corresponding to the pre-patency period that differs in the two populations, possibly according to differences in immunity related to parasite transmission.
Int J Epidemiol 2003; 32: 106-16
The survival benefit of measles immunization may not be explained entirely by the prevention of measles disease: a community study from rural Bangladesh
Aaby P, Bhuiya A, Nahar L, Knudsen K, De Francisco A, Strong M
Department of Epidemiology Research, Danish Epidemiology Science Centre, Statens Seruminstitut, Copenhagen, Denmark. International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
OBJECTIVE: To examine whether the reduction in childhood mortality after immunization can be explained by the prevention of measles and its long-term effects.
METHODS AND DATA: We re-analysed an existing data set from Matlab, Bangladesh. During 1982-1985, measles immunization was used from 9 months of age in half of the study area, and the other half was used as an unvaccinated control area. A total of 8134 immunized children had been matched by age with 8134 non-immunized children; 578 children died during the follow-up period of 3 years. Using these data, we calculated the vaccine effectiveness against death (VED) controlling for significant factors in a matched analysis. In the absence of measles, there should be no difference in mortality between immunized, uninfected children and non-immunized, uninfected children. We therefore calculated VED after the exclusion of all measles cases in the survival analysis. To assess the long-term effects of measles, we compared survival of unvaccinated children after measles disease with children who had not yet contracted measles.
RESULTS: Prior to immunization and again after 1985, childhood mortality rates were 10% lower in the area that had received immunization. Though measles deaths only constituted 12.4% of the non-accidental deaths, the VED controlling for significant factors was 49% (95% CI: 38-58%). The vaccine was protective against measles death throughout the study, but it also had a marked effect against other causes of death, particularly diarrhoea and oedema. This effect may have been particularly strong in the first 6 months after immunization (VED = 74, 95% CI: 57-84%). The VED was only reduced from 49% to 43% (95% CI: 31-54%) when measles cases were excluded in the survival analysis. Controlling for background factors, mortality among measles cases was increased during the acute phase (0-45 days) (mortality ratio [MR] = 17.35, 95% CI: 11.9-25.3) and in the following 1(1/2) months (MR = 2.35, 95% CI: 0.95-5.84). However, post-measles cases had significantly lower mortality than uninfected, non-immunized children in the following 9 months (MR = 0.40, 95% CI: 0.16, 0.98). CONCLUSIONS: The non-randomized character of the original study and the possibility of uncontrolled confounding between the two areas prevent a precise estimate of the effectiveness of measles vaccine, but it is likely to have been substantial. Though there may have been some underreporting of cases of measles, the prevention of measles infection can only explain a limited part of the observed impact of measles immunization in Bangladesh. Furthermore, mortality may be reduced after the acute phase of measles infection. The observations from Bangladesh are consistent with recent research from Africa suggesting that measles immunization may have non-specific beneficial effects on survival.
Trop Doct 2003; 33: 88-91
Motives, sexual behaviour, and risk factors associated with HIV in individuals seeking voluntary counselling and testing in a rural district of Malawi
Zachariah R, Spielmann MP, Harries AD, Buhendwa L, Chingi C
Medecins sans Frontieres, Thyolo, Malawi. email@example.com
A study was conducted among individuals seeking voluntary HIV counselling and testing (VCT) in order to (a) describe their motives and source(s) of information, (b) describe their sexual behaviour; and (c) identify risk factors associated with HIV infection. Of 723 individuals who sought VCT, the most common reason (50%) was recent knowledge of HIV/AIDS and a desire to know their HIV status. The majority (77%) underwent VCT after being encouraged by others who knew their status. Ninety five per cent reported sexual encounters, with 337 (49%) engaging in unprotected sex. HIV prevalence was 31% and an HIV-positive status was associated with being female, being over 25 years of age and/or being a farmer. There is a demand for VCT, and the service provides an opportunity for intensive education about HIV/AIDS prevention on a one-to-one basis. It could also be an entry point to prevention and care for those who are infected.
Acta Trop 2003; 85: 339-47
Epidemiological assessment of Schistosoma haematobium-induced kidney and bladder pathology in rural Zimbabwe
Brouwer KC, Ndhlovu PD, Wagatsuma Y, Munatsi A, Shiff CJ
The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, 615 N. Wolfe Street, 21205, Baltimore, MD, USA
Clinical outcome of Schistosoma haematobium infection may vary significantly, ranging from mild symptoms to severe damage of urinary tract organs. This present study was undertaken to assess the relationship of a number of epidemiological and parasitological parameters with disease outcome in children from rural Zimbabwe. We surveyed 551 primary school students from three schools in the Chikwaka Communal Lands for schistosomiasis; 59.7% were infected with S. haematobium. Ultrasound examination of 189 of the infected students revealed that 50% had pathological changes of their bladder and 36% had abnormal pyelon dilation of at least one of their kidneys. Intensity of infection, certain water contact behaviours, male gender, proteinuria, and self-perceived haematuria were associated with increased bladder damage. Strenuous playing was negatively associated with pathology, especially for those with the highest grade of bladder damage. Kidney pathology was significantly linked with fatigue and pain upon urination and was more prevalent in students from schools closest to the major river systems. Our findings suggest that pathology due to urinary schistosomiasis is widespread and symptomatic in this population. The associations with bladder and kidney pathology can be used to predict disease severity and may be useful in targeting treatment to those most at risk.
Trop Med Int Health 2003; 8: 290-296
Malaria morbidity, treatment-seeking behaviour, and mortality in a cohort of young children in rural Burkina Faso
Muller O, Traore C, Becher H, Kouyate B
Department of Tropical Hygiene and Public Health of the Ruprecht-Karls-University, Heidelberg, Germany Centre de Recherche en Sante de Nouna, Nouna, Burkina Faso
OBJECTIVE: To describe the pattern of fever-associated morbidity, treatment-seeking behaviour for fever episodes, and cause-specific mortality in young children of a malaria-holoendemic area in rural Burkina Faso.
METHODS: In a longitudinal community-based intervention study, 709 representative children aged 6-31 months were followed daily over 6 months (including the main malaria transmission period) through village-based field staff.
RESULTS: Of 1848 disease episodes, 1640 (89%) were fever episodes, and of those, 894 (55%) were attributed to malaria (fever + >/=5000 parasites/ml). Eighty-five percent of fever episodes were treated, mainly with chloroquine and paracetamol, 69% of treatments took place in households, 16% in local health centres, 13% in villages, and 1% in hospitals. Treatment-seeking in a health centre or hospital was associated with accessibility and disease severity. Cerebral malaria and malnutrition-associated diarrhoea were the most frequently diagnosed causes of death. While most children with a post-mortem diagnosis of diarrhoea had not received any treatment, children who died of malaria had often received insufficient treatment. In particular, there was a lack of an appropriate second-line treatment at formal health services after chloroquine treatment had failed to resolve symptoms.
CONCLUSIONS: These findings call for more effective prevention and treatment of malaria, malnutrition and diarrhoea in rural African communities, as well as for better supervision of existing malaria treatment guidelines in formal health services.
Int J STD AIDS 2003; 14: 208-15
Treponemal infection rates, risk factors and pregnancy outcome in a rural area of Senegal
Lagarde E, Guyavarch E, Piau JP, Gueye-Ndiaye A, Seck K, Enel C, Pison G, Ndoye I, Mboup S
Institut National de Sante et de la Recherche Medicale (INSERM), Unite 88, Saint-Maurice, Paris, France
A rural population of east Senegal has been under demographic surveillance for more than 30 years and a high rate of infertility has been reported. The aim of the study is to describe HIV and treponemal infection epidemiology and association with outcome of pregnancy in a population of rural Senegal. A population-based cross-sectional study was conducted among 952 randomly-selected adults of a rural community of Senegal. No participant was found to be infected with HIV, 11% had evidence of past syphilis and 5% of active syphilis. Active syphilis was associated among men with age, long-term mobility and having partners in an urban area in the last 12 months and among women with being divorced or widowed. No association was found between past or active syphilis and abortion or stillbirth but women aged 40 and more with past or active syphilis were significantly more likely to have had no history of gestation than women with no evidence of syphilis infection. In conclusion our results call for more research to understand the epidemiology of treponemal infection and to elucidate types of Treponema pallidum involved.
Int J STD AIDS 2003; 14: 185-8
Sexually transmitted infections and sexual behaviour among commercial sex workers in a rural district of Malawi
Zachariah R, Spielmann MP, Harries AD, Nkhoma W, Chantulo A, Arendt V
Medecins sans Frontieres - Luxembourg, Thyolo District, Malawi
In Thyolo District, Malawi, a study was conducted among commercial sex workers (CSWs) attending mobile clinics in order to; determine the prevalence and pattern of sexually transmitted infections (STIs), describe sexual behaviour among those who have an STI and identify risk factors associated with 'no condom use'. There were 1817 CSWs, of whom 448 (25%) had an STI. Of these, the commonest infections included 237 (53%) cases of abnormal vaginal discharge, 109 (24%) cases of pelvic inflammatory disease and 95 (21%) cases of genital ulcer disease (GUD). Eighty-seven per cent had sex while symptomatic, 17% without condoms. Having unprotected sex was associated with being married, being involved with commercial sex outside a known rest-house or bar, having a GUD, having fewer than two clients/day, alcohol intake and having had no prior medication for STI. The high levels of STIs, particularly GUDs, and unprotected sex underlines the importance of developing targeted interventions for CSWs and their clients.
J Biosoc Sci 2003; 35: 189-99
The association between HIV and fertility in a cohort study in rural Tanzania
Hunter SC, Isingo R, Boerma JT, Urassa M, Mwaluko GM, Zaba B
Centre for Population Studies, London School of Hygiene and Tropical Medicine, London
Recent studies in sub-Saharan Africa have shown that fertility is reduced among HIV-infected women compared with uninfected women. The size and pattern of this fertility reduction has important implications for antenatal clinic-based surveillance of the epidemic and also for estimates and projections of the demographic impact of the epidemic. This paper examines the association between HIV and fertility in Kisesa, a rural area in Tanzania, where HIV prevalence among adults is about 6% and gradually increasing. The analysis is based on data obtained through a demographic surveillance system in Kisesa during 1994-98 and two large sero-surveys of all residents in 1994-95 and 1996-97. The HIV-associated fertility reduction among women was investigated by estimating fertility rates by HIV status and prevalence rates by fertility status. A substantial reduction (29%) was observed in fertility among HIV-infected women compared with HIV-uninfected women. The fertility reduction was most pronounced during the terminal stages of infection, but no clear association with duration of infection was observed. Use of modern contraception was higher among HIV-infected women. However, both among contracepting and non-contracepting women, a substantial reduction in fertility was seen among HIV-infected women.