Patellofemoral Pain Syndrome Is Associated With Chronic Disease and Allergies in 60 997 Distance Runner Race Entrants: SAFER XXX Study.

OBJECTIVE: Patellofemoral pain syndrome (PFPS) is a common running-related injury. Independent risk factors associated with PFPS have not been described in a large cohort of distance runners. DESIGN: Descriptive, cross-sectional study. SETTING: 21.1 and 56 km Two Oceans Marathon races (2012-2015). PARTICIPANTS: 60 997 race entrants. ASSESSMENT OF RISK FACTORS: Participants completed a compulsory prerace medical screening questionnaire (history of PFPS in the past 12 months, n = 362; no injury history, n = 60 635). Selected risk factors associated with a history of PFPS were explored using univariate & multivariate analyses: demographics, training/running variables, history of chronic diseases (composite chronic disease score), and any allergy. MAIN OUTCOME MEASURES: Prevalence ratios (PRs, 95% confidence intervals). RESULTS: Risk factors associated with PFPS (univariate analysis) were increased years of recreational running (PR = 1.09; P = 0.0107), older age (>50 years), and chronic diseases (PR > 2): gastrointestinal disease (PR = 5.06; P < 0.0001), cardiovascular disease (CVD) (PR = 3.28; P < 0.0001), nervous system/psychiatric disease (PR = 3.04; P < 0.0001), cancer (PR = 2.83; P = 0.0005), risk factors for CVD (PR = 2.42; P < 0.0001), symptoms of CVD (PR = 2.38; P = 0.0397), and respiratory disease (PR = 2.00; P < 0.0001). Independent risk factors (multivariate analysis) associated with PFPS (adjusted for age, sex, and race distance) were a higher chronic disease composite score (PR = 2.68 increased risk for every 2 additional chronic diseases; P < 0.0001) and a history of allergies (PR = 2.33; P < 0.0001). CONCLUSIONS: Novel independent risk factors associated with PFPS in distance runners are a history of multiple chronic diseases and a history of allergies. Identification of chronic diseases and allergies should be considered as part of the clinical assessment of a runner presenting with a history of PFPS.

Social Network Lifestyle Interventions Reduce Non-Communicable Diseases Risk Factors in Financial Sector Employees: Randomized Controlled Trial.

OBJECTIVE: To determine if scientifically based social network (Facebook) lifestyle interventions reduce 10-year cardiovascular disease (CVD) risk. METHODS: Financial sector employees (n = 300) were equally randomly assigned: Facebook plus Health Professionals (FB+HP), Facebook (FB), or control (C). We report changes in 10-year Framingham risk score (FRS) for CVD (%) and risk factors over 12 months. RESULTS: FRS did not change within and between groups. Overweight (-7.4% vs -5.6%, P  = 0.005) and diabetes risk (-10.7% vs 0.2%, P  = 0.011) reduced significantly in FB+HP versus FB and C, respectively. Inadequate fruit/vegetable intake (-9.4% vs 3.6%, P  = 0.011) and smoking (-0.7% vs 14.9%) reduced significantly in FB versus C. No significant changes in physical activity, central obesity, hypertension, and hypercholesterolemia between groups. CONCLUSIONS: Scientifically based social network lifestyle intervention programs could be included in workplace health promotional programmes to improve certain non-communicable disease risk factors.

Risk factors for not finishing an ultramarathon: 4-year study in 23,996 race starters, SAFER XXI.

BACKGROUND: Limited data support prerace medical screening to identify risk factors for not finishing an endurance running race. The aim of the study was to determine risk factors associated with not finishing an ultramarathon. METHODS: A prospective, cross-sectional study of Two Oceans ultramarathon (56 km) race starters who completed a prerace medical screening questionnaire. Race day environmental conditions were recorded on race day. Univariate analyses of risk factors associated with the did-not-finish (DNF) included race day factors and prerace medical screening history. RESULTS: Risk factors for DNF amongst 23,996 starters during the 56 km race included older age and females (P<0.0001). After adjusting for age and sex, the following were significant univariate risk factors: fewer years of running (P<0.0001), less previous race experience (P<0.0001), less training/racing per week (P=0.0002), lower average weekly training distance (P=0.0016), slower race vs. training speed (P<0.0001), lack of allergies (P=0.0100) and average wet-bulb globe temperature (P<0.0001). CONCLUSIONS: Females, older age, training-related factors (less training/racing, average weekly training distance, race vs. training speed) and average wet-bulb temperature, were risk factors for not finishing an ultramarathon. The results may not only assist runners and coaches in race preparation, but also have clinical implications for the medical planning prior to races.

Pre-race screening and stratification predicts adverse events-A 4-year study in 29585 ultra-marathon entrants, SAFER X.

BACKGROUND: Pre-race screening and risk stratification in recreational endurance runners may predict adverse events (AEs) during a race. AIM: To determine if pre-race screening and risk stratification predict AEs during a race. METHODS: A total of 29 585 participants (Male 71.1%, average age = 42.1 years; Female 28.9%, average age = 40.2 years) at the Two Oceans ultra-marathon races (56 km) completed a pre-race medical screening questionnaire and were risk stratified into four pre-specified groups [very high risk (VHR; existing cardiovascular disease-CVD:3.2%), high risk (HR; risk factors for CVD:10.5%), intermediate risk (IR; existing other chronic disease, medication use or injury:53.3%), and low risk (LR:33.0%)]. Race starters, finishers, and medical encounters (ME) were recorded. Did-not-start (DNS) rate (per 1000 entrants that did-not-start), did-not-finish (DNF) rate (per 1000 starters that did-not-finish), AE rate [per 1000 starters that either DNF or had an ME], and ME rate (per 1000 starters with an ME) were compared across risk categories. RESULTS: Adverse events were significantly higher (per 1000 starters; 95%CI) in the VHR (68.9; 52.4-89.9:P = .0407) compared with the LR (51.3; 46.5-56.7). The DNS rate was significantly different between the IR (190.3; 184.0-196.9) and LR (207.4; 199.2-216.0: P = .0011). DNF rates were not different in the VHR (56.4; 41.9-75.9) compared to LR (44.2; 39.7-49.1: P = .1295), and ME rate was also not different between risk categories, however, VHR (12.9; 7.0-23.9) was approaching significance compared to LR (6.9; 5.2-9.1: P = .0662). CONCLUSION: Pre-race medical screening and risk stratification may identify athletes at higher risk of AEs. Further studies should be performed in larger cohorts to clarify the role of pre-race medical screening in reducing AEs in endurance runners.

Prerace medical screening and education reduce medical encounters in distance road races: SAFER VIII study in 153 208 race starters.

OBJECTIVES: To examine the efficacy and feasibility of an online prerace medical screening and educational intervention programme for reducing medical complications in long-distance races. METHODS: This was an 8-year observational study of medical encounter rates among 153 208 Two Oceans race starters (21.1 and 56 km) in South Africa. After the first 4-year control (CON) period, we introduced an online prerace medical screening (based on European pre-exercise screening guidelines) and an automated educational intervention programme. We compared the incidence of medical encounters (per 1000 starters; all and serious life threatening) in the CON versus the 4-year intervention (INT) period. RESULTS: In comparison to the CON period (2008-2011: 65 865 starters), the INT period (2012-2015: 87 343 starters) had a significantly lower incidence (adjusted for age group, sex, race distance) of all medical encounters by 29% (CON=8.6 (7.9-9.4); INT=6.1 (5.6-6.7), p<0.0001), in the 21.1 km race by 19% (CON=5.1 (4.4-5.9); INT=4.1 (3.6-4.8), p=0.0356) and in the 56 km race by 39% (CON=14.6 (13.1-16.3); INT=9.0 (7.9-10.1), p<0.0001). Serious life-threatening encounters were significantly reduced by 64% (CON=0.6 (0.5-0.9); INT=0.2 (0.1-0.4); p=0.0003) (adjusted for age group and sex). Registration numbers increased in the INT period (CON=81 345; INT=106 743) and overall % race starters were similar in the CON versus INT period. Wet-bulb globe temperature was similar in the CON and INT periods. CONCLUSION: All medical encounters and serious life-threatening encounters were significantly lower after the introduction of a prescreening and educational intervention programme, and the programme was feasible.

Novel Factors Associated With Analgesic and Anti-inflammatory Medication Use in Distance Runners: Pre-race Screening Among 76 654 Race Entrants-SAFER Study VI.

OBJECTIVE: Analgesic/anti-inflammatory medication (AAIM) increases the risk of medical complications during endurance races. We determined how many runners use AAIM before or during races, AAIM types, and factors associated with AAIM use. DESIGN: Cross-sectional study. SETTING: 21.1-km and 56-km races. PARTICIPANTS: Seventy-six thousand six hundred fifty-four race entrants. METHODS: Participants completed pre-race medical screening questions on AAIM use, running injury or exercise-associated muscle cramping (EAMC) history, and general medical history. MAIN OUTCOME MEASURES: Analgesic/anti-inflammatory medication use, types of AAIM (% runners; 95% confidence interval), and factors associated with AAIM use (sex, age, race distance, history of running injury or EAMC, and history of chronic diseases) [prevalence ratio (PR)]. RESULTS: Overall, 12.2% (12.0-12.5) runners used AAIM 1 week before and/or during races (56 km = 18.6%; 18.0-19.1, 21.1 km = 8.3%; 8.1-8.6) (P < 0.0001). During races, nonsteroidal anti-inflammatory drugs (NSAIDs) (5.3%; 5.1-5.5) and paracetamol (2.6%; 2.4-2.7) were used mostly. Independent factors (adjusted PR for sex, age, and race distance; P < 0.0001) associated with AAIM use were running injury (2.7; 2.6-2.9), EAMC (2.0; 1.9-2.1), cardiovascular disease (CVD) symptoms (2.1; 1.8-2.4), known CVD (1.7; 1.5-1.9), CVD risk factors (1.6; 1.5-1.6), allergies (1.6; 1.5-1.7), cancer (1.3; 1.1-1.5), and respiratory (1.7; 1.6-1.8), gastrointestinal (2.0; 1.9-2.2), nervous system (1.9; 1.7-2.1), kidney/bladder (1.8; 1.6-2.0), endocrine (1.5; 1.4-1.7), and hematological/immune (1.5; 1.2-1.8) diseases. CONCLUSIONS: 12.2% runners use AAIM before and/or during races, mostly NSAIDs. Factors (independent of sex, age, and race distance) associated with AAIM use were history of injuries, EAMC, and numerous chronic diseases. We suggest a pre-race screening and educational program to reduce AAIM use in endurance athletes to promote safer races.

Underlying Chronic Disease, Medication Use, History of Running Injuries and Being a More Experienced Runner Are Independent Factors Associated With Exercise-Associated Muscle Cramping: A Cross-Sectional Study in 15778 Distance Runners.

BACKGROUND: Exercise-associated muscle cramping (EAMC) is a significant medical complication in distance runners, yet factors associated with EAMC are poorly documented. OBJECTIVE: To document risk factors associated with EAMC in runners. DESIGN: Cross-sectional study. SETTING: Two ocean races (21.1 km, and 56 km). PARTICIPANTS: Fifteen thousand seven hundred seventy-eight race entrants. METHODS: Participants completed a prerace medical history screening tool including: training, cardiovascular disease (CVD), risk factors for, and symptoms of CVD, history of diseases affecting major organ systems, cancer, allergies, medication use, and running injury. Runners were grouped as having a history of EAMC (hEAMC group = 2997) and a control group (Control = 12 781). RESULTS: Independent factors associated with a higher prevalence ratio (PR) of hEAMC were any risk factor for CVD (PR = 1.16; P = 0.0002), symptoms of CVD (PR = 2.38; P < 0.0001), respiratory disease (PR = 1.33; P < 0.0001), gastrointestinal disease (PR = 1.86; P < 0.0001), nervous system or psychiatric disease (PR = 1.51; P < 0.0001), kidney or bladder disease, (PR = 1.60; P < 0.0001), haematological or immune disease (PR = 1.54; P = 0.0048), cancer (PR = 1.34; P = 0.0031), allergies (PR = 1.37; P < 0.0001), regular medication use (PR = 1.80; P < 0.0001), statin use (PR = 1.26; P = 0.0127), medication use during racing (PR = 1.88; P < 0.0001), running injury (PR = 1.66; P < 0.0001), muscle injury (PR = 1.82; P < 0.0001), tendon injury (PR = 1.62; P < 0.0001), and runners in the experienced category (PR = 1.22; P < 0.0001). CONCLUSION: Novel risk factors associated with EAMC in distance runners were underlying chronic disease, medication use, a history of running injuries, and experienced runners. These factors must be identified as possible associations, and therefore be considered in the diagnosis and treatment of EAMC.

Predictors of Alcohol Use during Pregnancy among Women Attending Midwife Obstetric Units in the Cape Metropole, South Africa.

INTRODUCTION: Little is known about the nature and extent of substance use among pregnant women in Cape Town (South Africa) despite the very high levels of substance use and related consequences such as FASD in this part of the country. The aim of the study was to determine predictors of alcohol use among pregnant women. METHODS: A cross-sectional survey was conducted among pregnant women attending 11 Midwife Obstetric Units (MOUs) in greater Cape Town. A two-stage cluster survey design was used. In total, 5231 pregnant women were screened to assess self-reported prevalence estimates. Of these, 684 (13.1%) were intentionally sub-sampled and completed an interviewer-administered questionnaire and provided a urine sample for biological screening. Univariate and multivariate statistical procedures were used to determine factors predictive of alcohol use. RESULTS: Findings highlight various demographic, social and partner substance use predictors for both self-reported and biologically verified alcohol use in two different models. Being Coloured, having a marital status other than being married, experiencing violence or aggression in the past 12 months compared to more than 12 months ago, having a partner who drinks, and partner drug use are all independently associated with higher odds of self-reported alcohol use. In contrast, only partner tobacco use is independently associated with higher odds of biologically verified alcohol use. CONCLUSION: Knowing the risk factors for alcohol use in pregnancy is important so that intervention efforts can accurately target those women in need of services. Intervention programs addressing risk factors of high-risk pregnant women are needed.

The association between environmental exposures during childhood and the subsequent development of Crohn's disease: A score analysis approach.

BACKGROUND: Environmental factors during childhood are thought to play a role in the aetiology of Crohn's Disease (CD). In South Africa, recently published work based on an investigation of 14 childhood environmental exposures during 3 age intervals (0-5, 6-10 and 11-18 years) has provided insight into the role of timing of exposure in the future development of CD. The 'overlapping' contribution of the investigated variables however, remains unclear. The aim of this study was to perform a post hoc analysis using this data and investigate the extent to which each variable contributes to the subsequent development of CD relative to each aforementioned age interval, based on a score analysis approach. METHODS: Three methods were used for the score analysis. Two methods employed the subgrouping of one or more (similar) variables (methods A and B), with each subgroup assigned a score value weighting equal to one. For comparison, the third approach (method 0) involved no grouping of the 14 variables. Thus, each variable held a score value of one. RESULTS: Results of the score analysis (Method 0) for the environmental exposures during 3 age intervals (0-5, 6-10 and 11-18 years) revealed no significant difference between the case and control groups. By contrast, results from Method A and Method B revealed a significant difference during all 3 age intervals between the case and control groups, with cases having significantly lower exposure scores (approximately 30% and 40% lower, respectively). CONCLUSION: Results from the score analysis provide insight into the 'compound' effects from multiple environmental exposures in the aetiology of CD.

Vitamin D Deficiency Increases the Risk for Moderate to Severe Disease Activity in Crohn's Disease Patients in South Africa, Measured by the Harvey Bradshaw Index.

OBJECTIVE: Vitamin D has immunoregulatory properties and appears to influence disease outcomes in patients with Crohn's disease (CD). The primary aim of this study was to evaluate the association between vitamin D status and CD activity in South Africa. METHODS: In a cross-sectional study performed between September 2011 and January 2013, serum 25-hydroxyvitamin D (25(OH)D) was measured in 186 consecutive patients with CD seen at 2 inflammatory bowel disease (IBD) centers and 199 healthy controls in the Western Cape, South Africa. Lifestyle and clinical variables were identified using an investigator-administered questionnaire, as well as clinical examination and patient case notes. Vitamin D status was evaluated in 2 ways: ≤ 20 ng/mL vs ≥ 21 ng/mL and ≤ 29 ng/mL vs ≥ 30 ng/mL. Disease activity was measured by the Harvey Bradshaw Index (HBI). Various 25(OH)D threshold concentrations for predicting a higher HBI score were also investigated. RESULTS: On multiple log-binomial regression analysis, higher HBI scores and not having taken vitamin D supplementation in the 6 months prior to enrollment were identified as risk factors for vitamin D deficiency in patients with CD, defined either as ≤ 20 ng/mL or as ≤ 29 ng/mL (p < 0.03). Compared to patients with HBI < 5, those with HBI ≥ 8 were 2.5 times more likely to have 25(OH)D concentrations ≤ 21 ng/mL (prevalence risk [PR] = 2.5; 95% confidence interval [CI], 1.21-6.30). The risk was similar, though not as high, when defined as ≤ 29 ng/mL (PR = 2.0; 95% CI, 1.13-3.51). When vitamin D deficiency was defined as <20, <30, <40, and <50 ng/mL, the sensitivity and specificity obtained were 44.9% and 78.8%; 75.5% and 62.4%; 86.7% and 44.7%; and 92.9% and 23.5%, respectively (area under the curve = 0.71; p < 0.0001). CONCLUSION: Low serum 25(OH)D was associated with increased CD activity in a South African cohort.

The relationship between sitting posture and seated-related upper quadrant musculoskeletal pain in computing South African adolescents: A prospective study.

BACKGROUND: There is evidence that consistent sitting for prolonged periods is associated with upper quadrant musculoskeletal pain (UQMP). It is unclear whether postural alignment is a significant risk factor. OBJECTIVE AND DESIGN: The aim of the prospective study (2010-2011) was to ascertain if three-dimensional sitting postural angles, measured in a real-life school computer classroom setting, predict seated-related UQMP. METHOD: Asymptomatic Grade 10 high-school students, aged 15-17 years, undertaking Computer Application Technology, were eligible to participate. Using the 3D Posture Analysis Tool, sitting posture was measured while students used desk-top computers. Posture was reported as five upper quadrant angles (Head flexion, Neck flexion; Craniocervical angle, Trunk flexion and Head lateral bending). The Computer Usage Questionnaire measured seated-related UQMP and hours of computer use. The Beck Depression Inventory and the Multidimensional Anxiety Scale for Children assessed psychosocial factors. Sitting posture, computer use and psychosocial factors were measured at baseline. UQMP was measured at six months and one-year follow-up. RESULTS: 211, 190 and 153 students participated at baseline, six months and one-year follow-up respectively. 34.2% students complained of seated-related UQMP during the follow-up period. Increased head flexion (HF) predicted seated-related UQMP developing over time for a small group of students with pain scores greater than the 90th pain percentile, adjusted for age, gender, BMI, computer use and psychosocial factors (p = 0.003). The pain score increased 0.22 points per 1° increase in HF. CONCLUSIONS: Classroom ergonomics and postural hygiene should therefore focus on reducing large HF angles among computing adolescents.

The association between childhood environmental exposures and the subsequent development of Crohn's disease in the Western Cape, South Africa.

BACKGROUND: Environmental factors during childhood are thought to play a role in the aetiolgy of Crohn's Disease (CD). However the association between age at time of exposure and the subsequent development of CD in South Africa is unknown. METHODS: A case control study of all consecutive CD patients seen at 2 large inflammatory bowel disease (IBD) referral centers in the Western Cape, South Africa between September 2011 and January 2013 was performed. Numerous environmental exposures during 3 age intervals; 0-5, 6-10 and 11-18 years were extracted using an investigator administered questionnaire. An agreement analysis was performed to determine the reliability of questionnaire data for all the relevant variables. RESULTS: This study included 194 CD patients and 213 controls. On multiple logistic regression analysis, a number of childhood environmental exposures during the 3 age interval were significantly associated with the risk of developing CD. During the age interval 6-10 years, never having had consumed unpasteurized milk (OR = 5.84; 95% CI, 2.73-13.53) and never having a donkey, horse, sheep or cow on the property (OR = 2.48; 95% CI, 1.09-5.98) significantly increased the risk of developing future CD. During the age interval 11-18 years, an independent risk-association was identified for; never having consumed unpasteurized milk (OR = 2.60; 95% CI, 1.17-6.10) and second-hand cigarette smoke exposure (OR = 1.93; 95% CI, 1.13-3.35). CONCLUSION: This study demonstrates that both limited microbial exposures and exposure to second-hand cigarette smoke during childhood is associated with future development of CD.

The association between race and Crohn's disease phenotype in the Western Cape population of South Africa, defined by the Montreal Classification System.

BACKGROUND: Inter-racial differences in disease characteristics and in the management of Crohn's disease (CD) have been described in African American and Asian subjects, however for the racial groups in South Africa, no such recent literature exists. METHODS: A cross sectional study of all consecutive CD patients seen at 2 large inflammatory bowel disease (IBD) referral centers in the Western Cape, South Africa between September 2011 and January 2013 was performed. Numerous demographic and clinical variables at diagnosis and date of study enrolment were identified using an investigator administered questionnaire as well as clinical examination and patient case notes. Using predefined definitions, disease behavior was stratified as 'complicated' or 'uncomplicated'. RESULTS: One hundred and ninety four CD subjects were identified; 35 (18%) were white, 152 (78%) were Cape Coloured and 7(4%) were black. On multiple logistic regression analysis Cape Coloureds were significantly more likely to develop 'complicated' CD (60% vs. 9%, p = 0.023) during the disease course when compared to white subjects. In addition, significantly more white subjects had successfully discontinued cigarette smoking at study enrolment (31% vs. 7% reduction, p = 0.02). No additional inter-racial differences were found. A low proportion of IBD family history was observed among the non-white subjects. CONCLUSIONS: Cape Coloured patients were significantly more likely to develop 'complicated' CD over time when compared to whites.

Heroin users in Cape Town, South Africa: injecting practices, HIV-related risk behaviors, and other health consequences.

UN reports point to a steady increase in heroin use in a number of African countries, including South Africa. South Africa also has one of the highest HIV infection prevalence rates in the world. Given the link between intravenous heroin use and HIV transmission, this study aimed to investigate HIV-related risk behaviors among heroin users in the city. A snowballing or chain referral sampling technique was used to find 239 heroin users in Cape Town who were interviewed using a structured questionnaire. Overall, 24% of all the participants reported that they had injected heroin in the past 30 days and 89% of these had shared a needle at least once during that period. Condom use was irregular among the survey participants. Three percent stated that they were HIV positive. Heroin use has become a major concern in Cape Town and may still be increasing. While injecting use still appears to be fairly limited, this has the potential to change. Further debate is required regarding the introduction of harm reduction approaches that have been found to be effective elsewhere.

Paradoxical helminthiasis and giardiasis in Cape Town, South Africa: epidemiology and control.

BACKGROUND: South Africa has endorsed a World Health Assembly (WHA) resolution calling for control of soil-transmitted helminths (STHs). In Cape Town, services and housing that exist in old-established suburbs should minimise the prevalence of intestinal parasitic infections, even when residents are poor. Where families live in shacks in densely-populated areas without effective sanitation, more than 90% of children can be infected by STHs. The humoral immune response to worms theoretically favours infection by Mycobacterium tuberculosis and HIV. OBJECTIVES: Obtain estimates of gender-, age-, school-related and overall prevalence of helminthiasis and giardiasis in a low-income but well-serviced community. Assess possible sources of infection. Alert health services to the need for control measures and the threat from protozoal pathogens. Warn that the immune response to intestinal parasites may favour tuberculosis (TB) and HIV/AIDS. METHODS: A cross-sectional study of the prevalence of helminthiasis and giardiasis was carried out in a large, non-selective sample of children attending nine schools. Gender, school and age effects were related to non-medical preventive services, sewage disposal practices and possible sources of infection. RESULTS: The overall STH infestation rate was 55.8%. Prevalence was inluenced by school and age but not by gender. Eggs and cysts were seen at the following prevalence: Ascaris 24.8%; Trichuris 50.6%; Hymenolepis nana 2.2%; Enterobius 0.6%; Giardia 17.3%; hookworm 0.08%; and Trichostrongylus 0.1%. Approximately 60% of sewage sludge is used in a form that will contain viable eggs and cysts. CONCLUSION: Prevalence trends in this old community in Cape Town could indicate infection by swallowing eggs or cysts on food or in water, more than by exposure to polluted soil. Sewage sludge and effluent might be sources of infection. In adjacent, under serviced, newer communities, promiscuous defecation occurs. Probable vectors are discussed. The immune response to intestinal parasites might be a risk factor for HIV/AIDS and TB.

Paradoxical helminthiasis and giardiasis in Cape Town, South Africa: epidemiology and control.

BACKGROUND: South Africa has endorsed a World Health Assembly (WHA) resolution calling for control of soil-transmitted helminths (STHs). In Cape Town, services and housing that exist in old-established suburbs should minimise the prevalence of intestinal parasitic infections, even when residents are poor. Where families live in shacks in densely-populated areas without effective sanitation, more than 90% of children can be infected by STHs. The humoral immune response to worms theoretically favours infection by Mycobacterium tuberculosis and HIV. OBJECTIVES: Obtain estimates of gender-, age-, school-related and overall prevalence of helminthiasis and giardiasis in a low-income but well-serviced community. Assess possible sources of infection. Alert health services to the need for control measures and the threat from protozoal pathogens. Warn that the immune response to intestinal parasites may favour tuberculosis (TB) and HIV/AIDS. METHODS: A cross-sectional study of the prevalence of helminthiasis and giardiasis was carried out in a large, non-selective sample of children attending nine schools. Gender, school and age effects were related to non-medical preventive services, sewage disposal practices and possible sources of infection. RESULTS: The overall STH infestation rate was 55.8%. Prevalence was influenced by school and age but not by gender. Eggs and cysts were seen at the following prevalences: Ascaris 24.8%; Trichuris 50.6%; Hymenolepis nana 2.2%; Enterobius 0.6%; Giardia 17.3%; hookworm 0.08%; and Trichostrongylus 0.1%. Approximately 60% of sewage sludge is used in a form that will contain viable eggs and cysts. CONCLUSIONS: Prevalence trends in this old community in Cape Town could indicate infection by swallowing eggs or cysts on food or in water, more than by exposure to polluted soil. Sewage sludge and effluent might be sources of infection. In adjacent, under-serviced, newer communities, promiscuous defaecation occurs. Probable vectors are discussed. The immune response to intestinal parasites might be a risk factor for HIV/AIDS and TB.