Population In Southern India Research Articles

Adaptation of the ACE for a Malayalam speaking population in southern India

To adapt the Addenbrooke's Cognitive Examination (ACE) as a dementia-screening tool in a community in south India. To establish that items in the adapted version are equivalent to that in the original. The ACE was adapted into the local language, Malayalam (m-ACE), following cultural/linguistic modifications. To establish equivalence, qualitative comparisons were made (on the distribution of scores, percentage scoring at ceiling, and relative difficulty across items) between a UK sample receiving the ACE (n = 50; mean age = 67.9 +/- 7.4; education >/= 9, mean = 10.9 +/- 2.5) and a community-based educationally-stratified Indian sample receiving the m-ACE: 'India >/= 9' (n = 50; mean age = 67.8 +/- 5.2; education >/= 9, mean = 13.9 +/- 2.7) and 'India </= 8' (n = 50; mean age = 67.1 +/- 5.3; education </= 8, mean = 3.1 +/- 2.0). Most ACE items were retained. The score distribution (mean +/- 1SD), percentage at ceiling, and relative difficulties across items is comparable between the UK and the educationally equivalent India >/= 9 groups. Language, Naming, Attention and Orientation are relatively easy (>/= 80% at ceiling) and Recall and Verbal fluency are relatively difficult (</= 22% at ceiling). Although the percentage at ceiling were lower for the India </= 8 group, the order of relative difficulty was similar and the percentage scoring at floor was </= 10% on all except visuospatial item. The m-ACE provides a culture-fair Malayalam adaptation of the ACE with component items of equivalent difficulty.

Association of hypertension with cluster of insulin resistance syndrome factors: the Chennai Urban Population Study (CUPS-12).

The objective of this study was to investigate the association of insulin resistance and the cluster of insulin resistance syndrome (IRS) factors with hypertension in a native urban population from southern India. The Chennai Urban Population Study (CUPS) is an epidemiological study involving two residential areas in Chennai in southern India. Of the total of 1399 eligible subjects (age >or=20 years), 1262 (90.2%) participated in the study. Subjects were classified as hypertensives if they had systolic blood pressure (SBP) >or=140 mmHg or diastolic blood pressure (DBP) >or=0 mmHg, if they were known hypertensives, or if they were receiving treatment with antihypertensive drugs. Insulin resistance was computed using the homeostasis model assessment (HOMA IR). The overall prevalence of hypertension in the population was 22.1%. Prevalence of hypertension increased with an increase in quartiles of fasting insulin levels ( p=0.035) and HOMA IR ( p=0.03). Logistic regression analysis revealed that HOMA IR was significantly associated with hypertension, which was not altered even after addition of risk factors like age, smoking habit and alcohol consumption into the model. However, inclusion of variables associated with IRS abolished the association of insulin resistance with hypertension. Factor analysis identified four factors: factor 1 had positive loading of body mass index, age, systolic and diastolic blood pressures; factor 2 had positive loading of HOMA IR, fasting plasma glucose, triglycerides and body mass index; factor 3 had positive loading of waist-hip ratio, triglycerides and smoking habit and negative loading of alcohol consumption; factor 4 was loaded with age and serum cholesterol. Factor 1, the hypertension factor loaded with systolic and diastolic blood pressures, shared a correlation with the insulin resistance cluster through body mass index. Our results suggest that the "insulin resistance cluster" is associated with hypertension in this urban population of southern India.

Awareness of eye diseases in an urban population in southern India.

To assess the level of awareness of eye diseases in the urban population of Hyderabad in southern India. A total of 2522 subjects of all ages, who were representative of the Hyderabad population, participated in the population-based Andhra Pradesh Eye Disease Study. Of these subjects, 1859 aged > 15 years responded to a structured questionnaire on cataract, glaucoma, night blindness and diabetic retinopathy to trained field investigators. Having heard of the eye disease in question was defined as "awareness" and having some understanding of the eye disease was defined as "knowledge". Awareness of cataract (69.8%) and night blindness (60.0%) was moderate but that of diabetic retinopathy (27.0%) was low, while that of glaucoma (2.3%) was very poor. Knowledge of all the eye diseases assessed was poor. Subjects aged > or = 30 years were significantly more aware of all eye diseases assessed except night blindness. Multivariate analysis revealed that women were significantly less aware of night blindness (odds ratio (OR) = 0.78; 95% confidence interval (CI) = 0.63-0.97). Education played a significant role in awareness of these eye diseases. Study subjects of upper socioeconomic status were significantly more aware of night blindness (OR = 2.20; 95% CI = 1.29-3.74) and those belonging to upper and middle socioeconomic strata were significantly more aware of diabetic retinopathy (OR = 2.79; 95% CI = 2.19-3.56). Muslims were significantly more aware of cataract (OR = 2.36; 95% CI = 1.84-3.02) and less aware of night blindness (OR = 0.52; 95% CI = 0.42-0.64). The major source of awareness of the eye diseases was a family member/friend/relative suffering from that eye disease. These data suggest that there is a need for health education in this Indian population to increase their level of awareness and knowledge of common eye diseases. Such awareness and knowledge could lead to better understanding and acceptance of the importance of routine eye examinations for the early detection and treatment of eye diseases, thereby reducing visual impairment in this population.

Planning low vision services in India: A population-based perspective

Objective To assess the prevalence and causes of low vision in a population in southern India for planning low vision services. Design Population-based, cross-sectional study. Participants A total of 10,293 persons of all ages from 94 clusters representative of the population of the Indian state of Andhra Pradesh. Methods The participants underwent a detailed eye examination, including measurement of visual acuity with logarithm of the minimum angle of resolution charts, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, and stereoscopic dilated fundus evaluation. Automated threshold visual fields and slit-lamp and fundus photography were done when indicated using predefined criteria. Main outcome measures Low vision was defined as permanent visual impairment that was not correctable with refractive error correction or surgical intervention. The participants with best-corrected distance visual acuity <6/18 to perception of light or central visual field <10° because of an untreatable cause in both eyes were considered as having low vision. Results Low vision was present in 144 participants, an age, gender, and urban-rural distribution adjusted prevalence of 1.05% (95% confidence interval, 0.82%–1.28%). The most frequent causes of low vision included retinal diseases (35.2%), amblyopia (25.7%), optic atrophy (14.3%), glaucoma (11.4%), and corneal diseases (8.6%). Multivariate analysis showed that the prevalence of low vision was significantly higher with increasing age, and there was a trend for higher prevalence with decreasing socioeconomic status. Extrapolating these data to the estimated 1014 million population of India in the year 2000, 10.6 (95% confidence interval, 8.4–12.8) million people would have low vision. Conclusions These data imply that there is a significant burden of low vision in this population, suggesting the need for low vision services.

Angle-Closure Glaucoma in an Urban Population in Southern India

Angle-Closure Glaucoma in an Urban Population in Southern India

Ocular trauma in an urban population in southern India: the Andhra Pradesh Eye Disease Study.

To assess the cumulative prevalence of ocular trauma and presence of vision loss due to ocular trauma in an urban population in southern India. As part of the population-based Andhra Pradesh Eye Disease Study, 2522 people of all ages from 24 clusters representative of the population of Hyderabad city in southern India, underwent a detailed interview and standardized dilated ocular evaluation. An eye was considered to be blind due to trauma if best corrected distance visual acuity was worse than 6/60 due to trauma. One hundred and thirteen subjects gave a history of ocular trauma and another two had evidence of ocular trauma by examination, a combined age sex-adjusted rate of 3.97% (95% CI 2.52-5.42%). Blindness in one eye due to trauma was present in 17 subjects, and in both eyes in one subject, a combined age-sex-adjusted prevalence of 0.60% (95% CI 0.23-1.04%). Visual acuity in all the blind eyes except one was worse than 3/60. With multiple logistic regression, the odds of blindness in at least one eye due to trauma were highest for current age range of 30-39 years (odds ratio 6.33, 95% CI 1.69-23.77 compared with a current age of less than 30 years), were significantly higher for lower socioeconomic status (3.74, 95% CI 1.18 -11.84), and were higher for males (2.48, 95% CI 0.91-6.82) though this did not reach statistical significance. Trauma resulting in blindness had occurred by the age of 15 years in 55% of subjects, and before the age of 40 years in 92.1% of subjects; this had occurred most commonly while playing (53.6% of the cases). With multiple logistic regression, the odds ratios for any ocular trauma were significantly higher for males (2.10, 95% CI 1.40-3.15), and for labourers than for other occupations (2.50, 95% CI 1.62-3.86). Ocular trauma affects one in 25 people in this urban population in India, and one in 167 people in this population are estimated to be blind in at least one eye due to trauma. The majority of the trauma resulting in blindness occurs during childhood and young adulthood, and slightly more than half occurs while playing. Targeting mothers and children of lower socioeconomic strata in eye health awareness strategies to reduce blindness due to trauma needs to be considered in urban India.

Angle-closure glaucoma in an urban population in southern india: The andhra pradesh eye disease study

Objective To assess the prevalence and features of angle-closure glaucoma (ACG) in an urban population in southern India. Design A population-based, cross-sectional study. Participants A total of 2522 (85.4% of those eligible) persons of all ages, including 1399 persons 30 years of age or older, from 24 clusters representative of the population of Hyderabad city. Testing The participants underwent an interview and detailed eye examination that included logarithm of minimum angle of resolution visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, and gonioscopy; pupil dilatation and stereoscopic fundus evaluation was performed if the risk of angle-closure as a result of dilatation was not believed to be imminent. Humphrey threshold 24-2 visual fields (Humphrey Instruments Inc., San Leandro, CA) were performed when indicated by standardized criteria for disc damage or if intraocular pressure (IOP) was 22 mmHg or more. Main outcome measures An occludable angle was defined as pigmented posterior trabecular meshwork not visible by gonioscopy in three quarters or more of the angle circumference. Manifest primary angle-closure glaucoma (PACG) was defined as IOP of 22 mmHg or more or glaucomatous optic disc damage with visual field loss in the presence of an occludable angle. An IOP of 22 mmHg or more or glaucomatous optic disc damage in the presence of an occludable angle secondary to an obvious cause was defined as secondary ACG. Results Manifest PACG and occludable angles without ACG were present in 12 and 24 participants, respectively, with age- and gender-adjusted prevalence (95% confidence interval [CI]) of 0.71% (0.34%–1.31%) and 1.41% (0.73%–2.09%) in participants 30 years of age or older, and 1.08% (0.36%–1.80%) and 2.21% (1.15%–3.27%) in participants 40 years of age or older, respectively. With multivariate analysis, the prevalence of these two conditions considered together increased significantly with age ( P < 0.001); although not statistically significant, these were more common in females (odds ratio 1.70; 95% CI, 0.82–3.54) and in those belonging to lower socioeconomic strata as compared with middle and upper strata (odds ratio, 1.82; 95% CI, 0.88–3.74). The odds of manifest PACG were higher in the presence of hyperopia of more than 2 diopters ([D]; odds ratio, 3.69; 95% CI, 0.89–15.2). Only four of 12 participants (33.3%) with manifest PACG had been previously diagnosed, and one of 12 (8.3%) had peripheral iridotomy performed previously. Manifest PACG had caused blindness in one or both eyes in five of these 12 participants (41.7%); best-corrected distance visual acuity less than 20/400 in one or both eyes in four patients, and acuity less than 20/200 in one eye in another patient. Most (83.3%) of those with manifest PACG could be classified as having chronic form of the disease. We may have underestimated manifest PACG because visual fields were per- formed only on those with clinical suspicion of optic disc damage. Secondary ACG was present in two participants. Conclusions The prevalence of PACG in this urban population in southern India is close to that reported recently in a Mongolian population. A large proportion of the PACG in this population was undiagnosed and untreated. Because visual loss resulting from PACG is potentially preventable if peripheral iridotomy or iridectomy is performed in the early stage, strategies for early detection of PACG could reduce the high risk of blindness resulting from PACG seen in this urban population in India.

Open-angle glaucoma in an urban population in southern india: The andhra pradesh eye disease study

Objective To assess the prevalence and features of open-angle glaucoma in an urban population in southern India. Design A population-based cross-sectional study. Participants A total of 2522 persons (85.4% of those eligible) of all ages, including 1399 persons 30 years of age or older, from 24 clusters representative of the population of Hyderabad city. Testing The participants underwent an interview and detailed eye examination that included logarithm of minimum angle of resolution visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, dilatation, cataract grading, and stereoscopic fundus evaluation. Automated Humphrey threshold 24-2 visual fields (Humphrey Instruments Inc., San Leandro, CA) and optic disc photography were performed when indicated by standardized criteria for disc damage or if intraocular pressure (IOP) was 22 mmHg or more. Main outcome measures Definite primary open-angle glaucoma (POAG) was defined as obvious glaucomatous optic disc damage and visual field loss in the presence of an open-angle, and suspected POAG was defined as suspected glaucomatous optic disc damage without definite visual field loss. Ocular hypertension (OHT) was defined as IOP of 22 mmHg or more without glaucomatous optic disc damage or visual field loss in the presence of an open-angle. Glaucomatous optic disc damage or IOP of 22 mmHg or more secondary to an obvious cause and with an open-angle was defined as secondary open-angle glaucoma. Results Definite POAG, suspected POAG, and OHT were present in 27, 14, and 7 participants, respectively, with age- and gender-adjusted prevalence (95% confidence interval) of 1.62% (0.77%–2.48%), 0.79% (0.39%–1.41%), and 0.32% (0.10%–0.78%) in those 30 years of age or older, and 2.56% (1.22%–3.91%), 1.11% (0.43%–1.78%), and 0.42% (0.11%–1.12%) in those 40 years of age or older, respectively. The prevalence of POAG increased significantly with age using multivariate analysis ( P < 0.001). Only two of 27 participants (7.4%) with definite POAG had been previously diagnosed and treated, and 66.7% of the previously undiagnosed had IOP less than 22 mmHg. Fourteen of 27 participants (51.9%) with definite POAG had severe glaucomatous damage based on optic disc and visual field criteria, of which five participants (18.5%) had at least one blind eye as a result of POAG (all with best-corrected distance visual acuity less than 20/400 or central visual field less than 10°); the other 13 participants (48.1%) had moderate glaucomatous damage. Because visual fields and optic disc photography were not performed on all participants, the prevalence of POAG may have been underestimated. Secondary open-angle glaucoma was present in one participant as a result of angle recession. Conclusions The prevalence of open-angle glaucoma in this urban population in southern India is at least as much as that reported recently from white populations in developed countries. However, the vast majority of persons with glaucoma were undiagnosed in this population, and a large proportion of those having definite POAG already had severe glaucomatous damage.

Population based assessment of uveitis in an urban population in southern India

AIMTo assess the prevalence of active and inactive uveitis unrelated to previous surgery or trauma in an urban population in southern India.METHODSAs part of the Andhra Pradesh Eye Disease Study,...

Utilisation of eyecare services in an urban population in southern India: the Andhra Pradesh eye disease study

AIMTo assess utilisation of eyecare services by people with visual impairment <6/18 or equivalent visual field loss in the better eye in the urban population of Hyderabad in southern India.METHODS2522...

Population based assessment of diabetic retinopathy in an urban population in southern India

AIMTo assess the prevalence of diabetic retinopathy and the visual impairment caused by it in an urban population in southern India in order to determine its public health significance.METHODS2522 subjects...

Population-based assessment of the outcome of cataract surgery in an urban population in southern India

PURPOSE: To assess the outcome of cataract surgery in an urban population in southern India. METHODS: As part of a population-based cross-sectional epidemiologic study, the Andhra Pradesh Eye Disease Study, 2,522 people of all ages, including 1,399 individuals 30 years of age or older, from 24 clusters representative of the population of Hyderabad in southern India underwent a detailed interview and ocular evaluation including logarithm of minimal angle of resolution (logMAR) visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, dilation, cataract grading, aphakia/pseudophakia status, and stereoscopic fundus evaluation. Automated threshold visual fields and slit-lamp and fundus photography were performed when indicated by standardized criteria. Very poor outcome in an eye that had undergone cataract surgery was defined as presenting distance visual acuity worse than 20/200, and poor outcome was defined as visual acuity worse than 20/60 to 20/200. RESULTS: In subjects 50 years of age or older, after adjustment for age and sex distribution, the rate of having had cataract surgery in one or both eyes was 14.6% (95% confidence interval [CI], 11.4% to 17.8%). Of 131 eyes (91 subjects) that had undergone cataract surgery, 28 (21.4%; 95% CI, 14.4% to 28.4%) had very poor outcome and another 40 (30.5%; 95% CI, 22.6% to 38.4%) had poor outcome. The very poor outcome in 20 (71.4%) of 28 eyes and poor outcome in 23 (57.5%) of 40 eyes could be attributed to surgery-related causes or inadequate refractive correction. With multivariate analysis, very poor outcome as a result of surgery-related causes or inadequate refractive correction was more likely to be associated with intracapsular cataract extraction than with extracapsular cataract extraction (odds ratio, 9.34; 95% CI, 2.49 to 35.06) in subjects belonging to the lowest socioeconomic status (odds ratio, 4.92; 95% CI, 1.16 to 20.93) and with date of surgery 3 or fewer years before the survey than with more than 3 years (odds ratio, 4.52; 95% CI, 1.33 to 15.39). Also, very poor or poor outcome as a result of surgery-related causes or inadequate refractive correction was associated with women (odds ratio, 2.55; 95% CI, 1.06 to 6.16). CONCLUSIONS: The very high rate of very poor and poor visual outcome, predominantly as a result of surgery-related causes and inadequate refractive correction, in this urban population of India suggests that more attention is needed to improve the visual outcome of cataract surgery. In order to deal with cataract-related visual impairment in India, as much emphasis on surgical quality, refractive correction, and follow-up care is necessary as on the number of surgeries.

Burden of moderate visual impairment in an urban population in southern India

ObjectiveTo assess the prevalence and causes of moderate visual impairment in an urban population in southern India. DesignPopulation-based, cross-sectional study. ParticipantsA total of 2522 (85.4% of the eligible) persons of all ages, including 1399 persons 30 years of age or older, from 24 clusters representative of the population of Hyderabad city. TestingThe eligible subjects underwent a detailed ocular evaluation, including logarithm of the minimum angle of resolution (logMAR) visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, cataract grading, and stereoscopic dilated fundus evaluation. Automated threshold visual fields and slit-lamp and fundus photography were done when indicated by standardized criteria. Main outcome measureModerate visual impairment was defined as presenting distance visual acuity less than 20/40 to 20/200 or visual field loss by predefined standardized conservative criteria in the better eye. ResultsIn addition to the 1% prevalence of blindness in this sample reported earlier, moderate visual impairment was present in 303 subjects, an age-gender-adjusted prevalence of 7.2% (95% confidence interval [CI], 4.5%–9.9%; design effect, 2.7). The major cause of moderate visual impairment was refractive error (59.4%, 95% CI, 52.3%–66.5%) followed by cataract (25.3%, 95% CI, 19%–31.6%). Multivariate analysis showed that the prevalence of moderate visual impairment was significantly higher in those 40 years of age or older (odds ratio, 10.9; 95% CI, 8–15) and females (odds ratio, 1.89; 95% CI, 1.41–2.53) and lower in those belonging to the highest socioeconomic status (odds ratio, 0.27; 95% CI, 0.14–0.51). However, because of the pyramidal age distribution of the population, 38.1% of the total moderate visual impairment was present in those younger than 40 years of age. The proportion of moderate visual impairment caused by refractive error was higher in the younger than in the older age groups (P < 0.0001). ConclusionsProjecting the results to the 26.5% urban population of India, there would be 18.4 million (95% CI, 11.5–25.2 million) persons with moderate visual impairment in urban India alone. Refractive error was the major cause of moderate visual impairment in the population studied. The absolute proportion of moderate visual impairment in those younger than 40 years of age was considerable. The eyecare policy of India, apart from dealing with blindness, should address the issue of the relatively easily treatable uncorrected refractive error as the cause of moderate visual impairment in an estimated 10.9 million persons in urban India.

Aflatoxin Intake from Maize-Based Diets in a Rural Population in Southern India

The aflatoxin intake through the consumption of maize was assessed in 12 households in a rural population in southern India. This was based on the measurement of aflatoxin levels in cooked maize and the quantity of consumption of the maize. The average aflatoxin intakes in nine out of 12 household ranged from 0·33 to 1·5 μg day-1. Individual intakes varied from 0·08 to 2·22 μg day-1. When assessed on a body weight basis, aflatoxin intakes in the younger age groups were observed to be higher. The average intakes in different age groups 1–5, 5–12, 12–18 and above 18 years were observed to be 47, 35, 33 and 22 ng kg-1 body weight day-1, respectively. Aflatoxin intakes calculated from aflatoxin levels in maize before cooking tended to be higher by 36% when compared with intakes calculated from cooked maize. This significant difference (P<0·001) was attributed to the effect of cooking on aflatoxin levels in maize. © 1997 SCI.

Incidence of IDDM in children in urban population in Southern India

This study was carried out to estimate the incidence of childhood insulin dependent diabetes mellitus (IDDM) in an urban southern Indian population. A registry for IDDM has been set up in the city of Madras, South India. Details of newly diagnosed IDDM children, aged less than 15 years, were analysed retrospectively, for a period of 1991–1994. Primary sources were government and service hospitals, large diabetes clinics and secondary sources were diabetes camp, private diabetologists and endocrinologists. A capture-recapture method was used and the estimate of case in the population (1991 census) was calculated. Incidence (case/100 000) was calculated in the total group and then for boys and girls separately. The incidence for the 4 year period was 10.5/100 000/year (CI 5.0). The corresponding values for boys and girls were 12.6 ± 11 and 9.6 ± 4.7 respectively. The peak incidence was between 10 and 12 years. This is the first population based incidence data from India and showed that the incidence of childhood IDDM is not low in urban children.

Prevalence and factors influencing dental problems in a rural population of southern India.

Prevalence and factors influencing dental problems in a rural population of southern India.

The prevalence of bacterial intestinal pathogens in a healthy rural population in southern India.

In a one-year prospective survey bacterial intestinal pathogens unassociated with diarrhoeal episodes were isolated from 20.5% of stool samples from 48.5% of a stratified random sample of the population of a village in southern India. Campylobacter jejuni was the pathogen most frequently isolated, followed by enteropathogenic serotypes of Escherichia coli. The incidence of diarrhoea in the study population was lower than the frequency of isolation of bacterial intestinal pathogens. It is necessary to understand the prevalence of intestinal pathogens in this ecosystem to know the dynamics of intestinal infection and the pathogenesis of diarrhoea.

A sero-biochemical genetic study of Jalari and Brahmin caste populations of Andhra Pradesh, India.

Blood specimens from Jalari and Brahmin caste populations of Andhra Pradesh, India, were examined for blood groups, red cell enzymes, and serum proteins. Of 33 genetic loci studied, 16 were observed to be invariant among both the castes, while common polymorphism or rare variants were observed in one or both populations for the other loci. Three rare heterozygotes at the phosphoglucoisomerase locus, two different peptidase A variants occurring once each and single cases of rare 6-phosphogluconate dehydrogenase and transferrin variants were recorded. Also a few cases of hemoglobin AS and anhaptoglobinemia were observed. The difference in rare variants between the two castes is conspicuous but large differences in their gene frequencies at the polymorphic loci were not observed. It is pointed out that the frequency of rare variants in the tribal and caste populations of Southern India appears to be higher than observed in temperate-dwelling civilized populations.

Structured exploratory data analysis (SEDA) of finger ridge‐count inheritance: II. Association arrays in parent‐offspring and sib‐sib pairs

Familial similarity of the dermatoglyphic trait values of finger ridge-count scores and pattern intensity index is examined for 125 nuclear families from the Velanadu Brahmin population of Southern India by the method of association arrays. This methodology assesses parent-offspring and sibship similarity through a collection of measures of dependence that is sensitive to a variety of nonlinear trends and stochastic relationships between trait values. The method is used in conjunction with various weights to determine the relationship between family size and the level and form of dependence. These analyses reveal that siblings are most strongly associated for ridge-counts of the middle digit and less associated for the thumb and fifth digit ridge-counts. Further, sibship similarity for ridge-counts increases with family size for the thumb and fifth digit but remains relatively constant over all family sizes for the middle finger. Family size effects are also observed for total ridge-counts of the left hand, right hand, and both hands combined, and for the pattern intensity index. These effects of family size may be due to the most pronounced changes occurring in the amniotic environment between the first and second pregnancy, which are most strongly manifested in the sibship associations of smaller families.

Sickle cell anemia and trait in a population of southern India.

In an ethnic group in southern India, the Irula, seven individuals with sickle cell anemia were found to manifest only mild illness. Although a relatively high level of fetal hemoglobin was present in one, none of the factors thought to ameliorate the course of sickling disorders could be identified in the remaining six. In a random population survey, sickle hemoglobin was found in 90 of 292 Irula (31%). In those with sickle cell trait, the proportion of sickle hemoglobin in hemolysates (mean = 26%, range 19-32%) was substantially lower than that reported for any other population.