Characterization of the major surface glycoconjugates of Trypanosoma theileri

Trypanosoma theileri maintains a long-term extracellular infection with a low parasitaemia in bovids. The surface of this parasite is predicted to be decorated with several surface molecules including membrane surface proteases (MSPs), trans-sialidases and T. theileri putative surface proteins (TTPSPs). However, there are no experimental data to verify this hypothesis. Here, we have purified and partially characterized the surface glycoconjugates of T. theileri using biochemical and mass spectrometry-based approaches. The glycoconjugates fall into two classes: glycoproteins and glycolipids. Proteomic analysis of the glycoprotein fraction demonstrated the presence of MSPs and abundant mucin-like TTPSPs, with most predicted to be GPI-anchored. Mass spectrometric characterization of the glycolipid fraction showed that these are mannose- and galactose-containing glycoinositolphospholipids (GIPLs) that are larger and more diverse than those of its phylogenetic relative T. cruzi, containing up to 10 hexose residues and carrying either alkylacyl-phosphatidylinositol or inositol-phospho-ceramide (IPC) lipid components.

Pregnancy outcome in homozygous sickle cell disease: observations from the Jamaican Birth Cohort

OBJECTIVE

To document pregnancy outcome in homozygous sickle cell (SS) disease and in age-matched controls with a normal haemoglobin genotype followed from birth for up to 45 years.

METHODS

A total of 100 000 consecutive non-operative deliveries screened for sickle cell disease at the main Government maternity hospital in Kingston, Jamaica between 1973 and 1981 detected 311 (149 female) babies with SS disease who were matched by age and gender with 250 (129 female) controls with an AA haemoglobin phenotype. These individuals have been followed from birth with prospective assessment of menarche and detailed documentation of all pregnancies.

RESULTS

There were 177 pregnancies in 71 SS patients and 226 pregnancies in 74 AA controls. Mothers with SS disease had more spontaneous abortions (adjusted relative risk [aRR] 3.2, 95% CI 1.6-6.1), fewer live births (aRR 0.7, 95% CI 0.6-0.9) and their offspring were more likely to have a gestational age <37 weeks (aRR 2.1, 95% CI 1.1-3.7) and low birthweight <2.5 kg (aRR 3.0, 95% CI 1.6-5.3). They were more prone to acute chest syndrome (aRR 13.7, 95% CI 4.1-45.5), urinary tract infection (aRR 12.8, 95% CI 1.3-125.9), pre-eclampsia/eclampsia (aRR 3.1, 95% CI 1.1-8.8), retained placenta (aRR 10.1, 95% CI 1.1-90.3), sepsis (Fisher's Exact test 0.04) and pregnancy-related deaths (Fisher's Exact test 0.02). Four of five deaths were attributable to acute chest syndrome. There was no genotypic difference in pregnancy-induced hypertension or postpartum haemorrhage.

CONCLUSION

Pregnancy in SS disease carries risks for both mother and child. The variable characteristics of pregnancy-related deaths complicate their prevention.

TWEETABLE ABSTRACT

Pregnancy in SS disease compared with controls showed increased abortions and stillbirths, fewer live births and maternal deaths in 7% patients.

Foot ulceration and its association with mortality in diabetes mellitus: a meta-analysis

BACKGROUND

Diabetic foot ulcers portend an almost twofold increase in all-cause mortality compared with diabetes on its own.

AIM

To investigate the association between diabetic foot ulcers and risk of death.

METHODS

We performed a meta-analysis of all observational studies investigating the association between diabetic foot ulcers and all-cause mortality. Risk ratios and risk differences were pooled in a random-effects model. The I² statistic was used to quantify heterogeneity between studies.

RESULTS

Altogether, we identified 11 studies that reported 84 131 deaths from any cause in 446 916 participants with diabetes during a total of 643 499 person-years of follow-up. The crude event rate for all-cause mortality in individuals with diabetes who did not develop foot ulceration was 22% lower at 181.5 deaths (per 1000 person-years) than in those who developed foot ulcers (230.8 per 1000 person-years). Diabetic foot ulceration was associated with an increased risk of all-cause mortality (pooled relative risk 2.45, 95% CI 1.85-2.85). We did not observe any tangible differences in risk of all-cause mortality from diagnosis in studies reporting a mean duration of follow-up of ≤3 years (relative risk 2.43, 95% CI 2.27-2.61) or >3 years (relative risk 2.26, 95% CI 2.13-2.40) years. Funnel plot inspection revealed no significant publication bias among studies included in this meta-analysis.

CONCLUSIONS

Our study shows an excess rate of all-cause mortality in people with diabetic foot ulceration when compared to those without foot ulceration. It is imperative that early interventions to prevent foot ulceration and modify cardiovascular disease risk factors are put in place to reduce excess mortality.

The spectrum of neuropsychiatric lupus in a Black Caribbean population: a report of the Barbados National Lupus Registry

Objective The objective of this study was to examine neuropsychiatric lupus in a Black Caribbean population. Methods We reviewed Barbados National Lupus Registry patients with ≥4 American College of Rheumatology criteria and a diagnosis of neuropsychiatric lupus using the American College of Rheumatology 19 case definitions. Results From 366 patients with four or more American College of Rheumatology criteria for systemic lupus erythematosus, 55 (15%) had evidence of neuropsychiatric lupus. There were 51 females and four males (F:M = 13:1) with a median age of 31 years. A total of 76.4% had a single neuropsychiatric lupus complication and 23.6% had two or three complications occurring sequentially or concurrently. The top three complications were psychosis - 49.1% (95% CI 35.8, 62.5); ischaemic stroke - 32.7% (21.4, 46.5); and generalized tonic-clonic seizures - 12.7% (6.0, 24.8). Twelve of the American College of Rheumatology 19 neuropsychiatric syndromes were represented: 91.2% central; 8.8% peripheral. There were 521 observation years, and for 32 patients (58%) neuropsychiatric lupus was a presenting feature. For the remaining 23 (42%) the first neuropsychiatric lupus event came after systemic lupus erythematosus diagnosis - median time of two years. Of the 22 deaths, systemic lupus erythematosus nephritis caused almost half (45.5%) at a median age of 32. The prevalence of nephritis was lower in the neuropsychiatric lupus subgroup (25.5%) compared with the Barbados National Lupus Registry data (47%) ( P = 0.01). Ischaemic stroke caused 22.7% of deaths at a median age of 46 and was the main cause of chronic neurologic deficits amongst survivors. Conclusion Neuropsychiatric lupus was an early cause of morbidity in systemic lupus erythematosus with predominantly singular central nervous system complications, the most common of which was psychosis. Most deaths occurred at a young age, principally from systemic lupus erythematosus nephritis. Ischaemic stroke was the main neurologic cause of death and disability.

A checklist that enhances the provision of education during insulin initiation simulation: a randomized controlled trial

AIM

The study tested the hypothesis that doctors using an insulin information checklist during simulated insulin initiation would impart more information regarding insulin use.

METHODS

A total of 128 simulations were conducted. Doctors (n = 64) were recruited from practitioners recently completing internship (n = 19) and those established in primary care (n = 45). Both groups of doctors were strata randomized to control (n = 32) and intervention groups (n = 32), so that each group contained equal numbers. Doctors in each group experienced two identical simulations of insulin initiation with an intervening period of 10 min. Doctors in the intervention arm were introduced to an insulin initiation checklist, which they reviewed independently and utilized in the second simulation. Trained assessors captured the provision of education in 21 predefined educational areas. Differences in the change of the total education provided between the first and second simulations were assessed using linear regression.

RESULTS

The difference in the mean change of education provided between the first and second simulations within the 21 educational areas for the control and treatment groups was 9.7 [95% confidence interval (CI): 8.8-11.1, P < 0.001] - an increase of 46.2%. The difference for the 15 areas relevant to pen use was 7.3 (95% CI: 6.2-8.4, P < 0.001) - an increase of 51.6%.

CONCLUSIONS

The checklist resulted in doctors providing significantly more education applicable to syringe and insulin pen routes of insulin administration during simulations. Further research is needed on the checklist's impact on healthcare professionals and patient outcomes in the clinical context. (Clinical Trials Registry No: NCT02266303).

Global estimates of diabetes prevalence for 2013 and projections for 2035

INTRODUCTION

Diabetes is a serious and increasing global health burden and estimates of prevalence are essential for appropriate allocation of resources and monitoring of trends.

METHODS

We conducted a literature search of studies reporting the age-specific prevalence for diabetes and used the Analytic Hierarchy Process to systematically select studies to generate estimates for 219 countries and territories. Estimates for countries without available source data were modelled from pooled estimates of countries that were similar in regard to geography, ethnicity, and economic development. Logistic regression was applied to generate smoothed age-specific prevalence estimates for adults 20-79 years which were then applied to population estimates for 2013 and 2035.

RESULTS

A total of 744 data sources were considered and 174 included, representing 130 countries. In 2013, 382 million people had diabetes; this number is expected to rise to 592 million by 2035. Most people with diabetes live in low- and middle-income countries and these will experience the greatest increase in cases of diabetes over the next 22 years.

CONCLUSION

The new estimates of diabetes in adults confirm the large burden of diabetes, especially in developing countries. Estimates will be updated annually including the most recent, high-quality data available.

Homozygous sickle cell disease in Uganda and Jamaica a comparison of Bantu and Benin haplotypes

OBJECTIVE

To compare the haematological and clinical features of homozygous sickle cell (SS) disease in Bantu and Benin haplotypes in a cross-sectional study of 115 Ugandan patients attending the Sickle Cell Clinic at Mulago Hospital, Kampala, Uganda, with 311 patients in the Jamaican Cohort Study

METHODS

This involved comparison of clinical features and haematology with special reference to genetic determinants of severity including fetal haemoglobin levels, beta-globin haplotype and alpha thalassaemia status.

RESULTS

The Bantu haplotype accounted for 94% of HbS chromosomes in Ugandan patients and the Benin haplotype for 76% of HbS chromosomes in Jamaica. Ugandan patients were marginally more likely to have alpha thalassaemia, had similar total haemoglobin and fetal haemoglobin levels but had higher reticulocyte counts and total bilirubin levels consistent with greater haemolysis. Ugandan patients had less leg ulceration and priapism, but the mode of clinical presentation, prevalence of dactylitis, features of bone pain and degree of delay in sexual development, assessed by menarche, were similar in the groups. In Ugandan patients, a history of anaemic episodes was common but these were poorly documented.

CONCLUSION

The haematological and clinical features of the Bantu haplotype in Uganda were broadly similar to the Benin haplotype in Jamaica except for less leg ulceration and priapism and possibly greater haemolysis among Ugandan subjects. Anaemic episodes in Uganda were treated empirically by transfusion often without a clear diagnosis; better documentation including reticulocyte counts and observations on spleen size is necessary to evolve appropriate models of care.

Pattern of pregnancy weight gain in homozygous sickle cell disease and effect on birth size

OBJECTIVE

To assess pregnancy weight gain and newborn anthropometry in mothers with homozygous sickle cell (SS) disease and normal controls.

METHODS

An eleven-year retrospective review at the University Hospital of the West Indies, Kingston, Jamaica, revealed 128 singleton deliveries in women with SS disease who were matched by maternal age and birth date with 128 controls with a normal AA phenotype. Restriction to those commencing antenatal care before 16 weeks gestation resulted in the final study group of 80 SS patients and 115 AA controls. Weight and height were measured at first antenatal visit and weight at 20, 25, 30, 35 and 38 weeks gestation. Longitudinal regression used mothers'weight as the outcome, genotype as a predictor and gestational age as a random effect. Regression analyses of maternal weight on childhood anthropometry were repeated in separate maternal genotypes. Neonatal indices included gestational age, birthweight, head circumference and crown-heel length.

RESULTS

Mothers with SS disease had lower weight and body mass index at first antenatal clinic visit (p < 0.001). Total weight gain was 6.9 kg for SS women and 10.4 kg for AA controls (p < 0.001) and weekly weight gain 0.263 kg (95% CI 0.224, 0.301) and 0.396 kg (95% CI 0.364, 0.427) respectively. A significant relationship occurred between birthweight and maternal weight gain at 25-30 weeks gestation in AA controls but this relationship appears delayed in SS disease.

CONCLUSION

Different patterns of maternal weight gain in SS mothers and normal controls may have significance for the lower birthweight in SS mothers.

Bacterial vaginosis in female facility workers in north-western Tanzania: prevalence and risk factors

OBJECTIVES

To determine prevalence of, and risk factors for, bacterial vaginosis (BV) among herpes simplex virus (HSV) 2 seropositive Tanzanian women at enrollment into a randomised, placebo-controlled trial of HSV suppressive treatment.

METHODS

1305 HSV-2 seropositive women aged 16-35 years working in bars, guesthouses and similar facilities were interviewed, examined and tested for HIV, syphilis, Neisseria gonorrhoeae, Chlamydia trachomatis, BV, candidiasis and trichomoniasis. Factors associated with BV were analysed using logistic regression to estimate odds ratios and 95% confidence intervals.

RESULTS

BV prevalence was 62.9%; prevalence of Nugent score 9-10 was 16.1%. Independent risk factors for BV were work facility type, fewer dependents, increasing alcohol consumption, sex in the last week (adjusted OR 2.03; 95% CI 1.57 to 2.62), using cloths or cotton wool for menstrual hygiene, HIV (adjusted OR 1.41; 95% CI 1.09 to 1.83) and Trichomonas vaginalis infection. There was no association between BV and the frequency or method of vaginal cleansing. However, BV was less prevalent among women who reported inserting substances to dry the vagina for sex (adjusted OR 0.44; 95% CI 0.25 to 0.75).

CONCLUSION

BV was extremely prevalent among our study population of HSV-2 positive female facility workers in North-western Tanzania. Although recent sex was associated with increased BV prevalence, vaginal drying was associated with lower BV prevalence. Further studies of the effects of specific practices on vaginal flora are warranted.

Predicted declines in sickle allele frequency in Jamaica using empirical data

The high frequency of the sickle allele in some parts of Africa is understood to be a consequence of high malarial endemicity. One corollary of this is that the sickle allele frequency should be declining in populations of African ancestry that are no longer exposed to malaria. We have previously shown that there has been no change in sickle allele frequency in malaria-free Jamaica between two large-scale neonatal screening exercises conducted in 1973-1981 and 1995-2003. To evaluate the determinants of, and derive expected values for, sickle allele frequency in Jamaica, local empirical data were used to estimate the parameters of deterministic models of allele frequency decline. We found that although model predictions were broadly consistent with observed values in the 1973-1981 cohort, the predicted change in allele frequency between the two cohorts was larger than the observed, nonsignificant, reduction. Close agreement between predicted and observed values was only achieved by simulating a recent, marked increase in HbSS fitness. Thus, the "unexpected" persistence of the sickle allele in Jamaica may reflect the fact that the actual fitness among SS individuals is higher than that previously realized. If true, our models suggest that without substantial changes in current screening and counseling practice, there will be little "natural" reduction in sickle allele frequency for several hundred years. Better estimates of relative fitness will be helpful in refining these predictions and may aid in assigning health care priorities in Jamaica and the African Diaspora.

The frequency of the sickle allele in Jamaica has not declined over the last 22 years

The 'malaria hypothesis' predicts that the frequency of the sickle allele, which is high in malaria-endemic African populations, should decline with each generation in populations of African descent living in areas where malaria is no longer endemic. In order to determine whether this has been the case in Jamaica, we compared haemoglobin electrophoresis results from two hospital-based screening programmes separated by more than 20 years (i.e. approximately one generation). The first comprised 100,000 neonates screened between 1973 and 1981, the second, 104,183 neonates screened between 1995 and 2003. The difference in frequency of the sickle allele was small (5.47% in the first cohort and 5.38% in the second screening cohort) and not significant (Z = 1.23, P = 0.22). The same was true of the sickle trait frequency (10.05% in the first cohort and 9.85% in the second, Z = 1.45, P = 0.15). These differences were smaller than predicted under simple deterministic models based on the malaria hypothesis, and suggest that these models may not capture important determinants of allele and trait frequency decline (or persistence) in contemporary populations. Refining the expectations for allele and trait frequency change for Jamaica and other similar populations is an area for future study.

CDC-defined diseases and opportunistic infections in Jamaican children with HIV/AIDS

OBJECTIVE

To document the frequency of Centers for Disease Control and Prevention (CDC)-defined clinical conditions, opportunistic and co-infections among children with HIV/AIDS.

METHODS

This prospective, observational study reports the findings of 110 HIV-infected children followed in multicentre ambulatory clinics during September 1, 2002, to August 31, 2003, from the 239 children enrolled in the Kingston Paediatric and Perinatal HIV/AIDS Programme, Jamaica. We describe the clinico-pathologic characteristics of these children with HIV/AIDS, using the CDC criteria.

RESULTS

The client distribution by clinic site was as follows: the University Hospital of the West Indies, 71 (64.6%), Bustamante Hospital for Children, 23 (20.9%), Comprehensive Health Centre 13 (11.8/%) and Spanish Town Hospital, 3 (2.7%). The median age of the 110 children with HIV/AIDS was 6.0 years (range 0.9-17.5). Mode of transmission was primarily mother-to-child (88.0%) and only 4% maternal/infant pairs received antiretroviralprophylaxis. Grouped by CDC category: 17 (15.4%) were asymptomatic (N), 22 (20.0%) mildly symptomatic (A), 30 (27.3%) moderately symptomatic (B) and 41 (37.3%) severely symptomatic (C). The most common CDC-defining symptoms were lymphadenopathy (12, 42.8%) and asymptomatic (6, 21.4%) in category N; lymphadenopathy (30, 29.7%), dermatitis (20, 19.8%) and persistent or recurrent upper respiratory tract infections (20, 19.8%) in category A; bacterial sepsis (18, 34.6%) and recurrent diarrhoea (11, 21.2%) in category B; and wasting (28, 30.0%), encephalopathy (26, 27.9%), and serious bacterial infections (15, 16.1%) in category C; Pulmonary tuberculosis (7, 7.5%) and Pneumocystis (jiroveci) carinii pneumonia; (5, 5.4%) were the most frequent opportunistic infections. Streptococcus pneumoniae (10, 30.3%) was the most common invasive bacterial pathogen causing sepsis and Escherichia coli (14, 34.2%) was the most common bacterial pathogen causing urinary tract infections, among the cohort. Thirty-three per cent commenced antiretroviral drugs (ARVs). There were 57 hospitalizations and five deaths.

CONCLUSIONS

The study is an important step toward documentation of the natural history of paediatric HIV/AIDS in a primarily ARV-naive population from a developing country. It promotes training in paediatric HIV management as we move toward affordable access to antiretroviral agents in the wider Caribbean and the implementation of clinical trials.

Socio-demographic characteristics of HIV-exposed and HIV-infected Jamaican children

BACKGROUND

In the face of the continuing pandemic of HIV/AIDS, the burden of the disease is now largest in the resource-poor developing world. The Joint United Nations Programme on HIV/AIDS (UNAIDS) has listed the adult prevalence rate for the Caribbean as second only to Sub-Saharan Africa.

OBJECTIVE

To document the socio-demographic characteristics of paediatric and perinatal HIV/AIDS in Kingston, Jamaica.

METHODS

A cohort of HIV-infected pregnant women were identified at the leading maternity centres in Kingston and St Catherine and were enrolled in the Kingston Paediatric and Perinatal HIV/AIDS Programme. Infants born to mothers within the programme were prospectively enrolled. Infants and children identified after delivery, whether HIV-exposed or infected, were also enrolled (retrospective group). All were followed according to standardized protocols.

RESULTS

We report on a total of 239 children, 78 (prospective group) and 161 (retrospective group). Among the retrospective group, 68% were classified as infected. For the prospective group, the patients were recruited within twenty-four hours of birth in 98.7% of cases, whereas in the retrospective group, the median age of recruitment was 2.6 years. The median age of the mother was 27 years and that of the father was 33 years. There were seven teenage mothers. Twenty-six per cent of the children were in institutional care. Family size ranged from one to nine children--the median was two children. For those parents where occupation was reported, the majority held semi-skilled or unskilled jobs. Patients attended their regional clinics.

CONCLUSION

HIV/AIDS represents a significant human and financial burden on a developing country such as Jamaica and this underscores the need for urgent and sustained interventions to stem the epidemic.

Tuberculosis and HIV co-infections in Jamaican children

BACKGROUND

There has been a worldwide increased prevalence of tuberculosis (TB) in recent years, with a similar trend observed in Jamaica and more recently in children admitted to the University Hospital of the West Indies, Jamaica. Data regarding paediatric TB, especially as it relates to all aspects of HIV co-infection, are needed from developing countries in diverse geographic settings to enhance prevention and treatment policies (National Institutes of Health, Office of AIDS Research, FY 2005 Budgetary Planning Meeting, March 11, 2003, Washington, DC).

OBJECTIVE

To determine associated factors and outcomes of tuberculosis in HIV-infected and noninfected children in Jamaica.

METHOD

We reviewed records of children aged 0 - 12 years attending the University Hospital of the West Indies during January 1999 to December 2002. Associated factors and outcomes in HIV-infected and HIV-negative cases with TB were compared using exact statistical methods to account for the small number of children and an adjustment for multiple testing. TB diagnosis was determined using modified World Health Organization (WHO) criteria.

RESULTS

There was a significant increase of active TB cases from 1999 to 2002 with 24 children diagnosed over this period All 24 children (100%) had received the Bacillus-Calmette-Guerin (BCG) vaccine. Eleven (46%) of these were HIV-infected, all via mother-to-child transmission. HIV-infected children were statistically more likely to be older than non-infected children (mean 4.2 vs 2.6 years), and also to have failure to thrive, digital clubbing, hepatomegaly, splenomegaly, generalized adenopathy and negative Mantoux tests. Appropriate in-hospital anti-TB therapy was given. Hospital stay was longer (median 7.4 vs. 2.8 months) and death was more likely (7/11 vs 2/13) in HIV-infected vs non-infected children. Triple antiretroviral therapy was given in three of the 11 HIV-infected cases and this markedly improved outcome. Household family members with active TB were identified in twelve cases.

CONCLUSIONS

HIV and TB co-infection is an increasing problem in Jamaican children. Severity of illness and death is greater in HIV-infected children, despite appropriate anti-TB therapy. Antiretroviral drugs must be made available to this population. Efforts must be enhanced to reduce mother-to-child-transmission of HIV/AIDS and to strengthen the public health management of TB (contact tracing and completion of TB therapy by directly observed therapy) to eliminate the spread

Uptake of interventions, outcomes and challenges in caring for HIV-exposed infants in Kingston, Jamaica

BACKGROUND

In a few Caribbean islands, prevention of mother-to-child transmission (pMTCT) of HIV with zidovudine prophylaxis has reduced transmission rates from 27 - 44% to 5.5 - 9 %.

OBJECTIVES

To highlight the uptake of interventions, preliminary outcomes and challenges in caring for HIV-exposed infants in a pMTCT HIVprogramme in a resource-limited setting.

METHOD

A cohort of HIV-infected pregnant women were identified at the leading maternity centres in Greater Kingston through HIV counselling and testing and enrolled in the Kingston Paediatric and Perinatal HIV/AIDS Programme. Antiretroviralprophylaxis with zidovudine or nevirapine was given to the HIV-positive women and their newborns along with formula feeding. Some infants were enrolled retrospectively and followed irrespective of whether they had or had not received antiretroviral prophylaxis. A multidisciplinary team at the paediatric centres supervised protocol-driven management of the infants. Infants were followed for clinical progress and definitive HIV-infection status was to be confirmed at 18 months of age by ELISA or the Determine Rapid Test.

RESULTS

During September 1, 2002 through August 31, 2003, 132 HIV-exposed infants were identified. For those infants prospectively enrolled (78), 97% received antiretroviral prophylaxis and 90% were not breastfed For all HIV-exposed children, 90% received cotrimoxazole prophylaxis and 88% continued follow-up care. Ninety-two per cent of all the infants remained asymptomatic and five died; of these deaths one is possibly HIV-related (severe sepsis at 11 weeks). This infant was retrospectively identified, had received no antiretroviral prophylaxis and was breastfed The main programme challenges, which were overcome, included the impact of stigma, compliance with antiretroviral chemoprophylaxis, breast-milk substitution and follow-up care. Financial constraints and laboratory quality assurance issues limited early diagnosis of HIV infection.

CONCLUSION

Despite the challenges, the expected outcome is to prevent 50 new cases of HIV/AIDS in children living in Greater Kingston per year (300 over six years).

Newborn screening for sickle cell disease in Brazil: the Campinas experience

Newborn screening for sickle cell disease commenced in 1992 in Sao Paulo State and by the end of 2000, the programme covered 78 institutions in 36 municipalities with the screening of 281,884 babies. Initially based on liquid cord blood samples, these are being replaced by dried filter paper capillary samples to ease handling and avoid diagnostic confusion from maternal contamination. The prevalence of sickle cell trait (2.0%) and HbC trait (0.6%) increased significantly between 1996 and 2000, apparently because of improved detection rather than the later introduction of institutions serving populations with higher trait frequencies. There were 29 babies with homozygous sickle cell SS disease and 26 with sickle cell-haemoglobin C (SC) disease, the latter significantly exceeding expectation and possibly attributable to a nonrandom selection of partners. Sickle cell-beta thalassaemia syndromes were proportionately more common than in Jamaica, and it is possible that this results from interaction with other Brazilian populations carrying higher beta thalassaemia gene frequencies. The frequency of abnormal haemoglobins in this population is lower than in Jamaica, but clinically significant sickle cell disease occurred once in every 5527 births, comparable with the frequencies of other significant inborn errors of metabolism.

Paediatric HIV/AIDS in Jamaica. A hospital-based description

The continuing worldwide epidemic of adult HIV/AIDS has led to an increase in the number of HIV-positive children mainly through perinatal transmission. Although national data are available, there is no published report of the epidemiology of HIV/AIDS in children in Jamaica. A multicentre retrospective analysis of 183 HIV seropositive children admitted to hospitals in Jamaica between 1990 and 1996 was conducted. Ages at diagnosis were available for 172 patients with 61% diagnosed in the first year of life. Clinical histories were available for 129 patients with the primary presenting symptoms of infected children being failure to thrive, pneumonia, diarrhoea, dermatitis and lymphadenopathy. Classification was possible in 128 patients: 49 were exposed, 76 were infected and three were seroreverters. Infected children had a longer hospital stay than those classified as exposed or seroreverters. As of December 31, 1997, 125 patients had defaulted, nine patients were alive and 51 were reported dead with a median age of death of 12 months. From these data, it is estimated that the hospital-based HIV incidence among children in Jamaica increased from 0.149 per 10,000 person years in 1990 to 1.331 per 10,000 person years in 1996. This study demonstrates a rise in the estimated incidence of HIV/AIDS but we were unable to estimate survival reliably since the data required were not available for 75% of children identified. These data highlight the urgent need for targeted interventions to reduce vertical transmission of HIV as well as a need for prospective studies to establish reliable data on incidence and long-term outcome for HIV-infected children.

Red cell antibodies in patients with homozygous sickle cell disease: a comparison of patients in Jamaica and the United Kingdom

The transfusion history and frequency of red cell antibodies in patients with homozygous sickle cell (SS) disease have been compared in 190 subjects from the Jamaican cohort study and 37 patients attending a sickle cell clinic in Manchester, England. The proportion of patients transfused did not differ between the groups although the number of units transfused and the frequency of red cell antibodies were significantly greater in the Manchester group. Immune antibodies occurred in three Jamaicans (2.6% of those transfused) and 16 UK subjects (76% of those transfused). Multiple antibodies occurred in 10 (63%) UK subjects but in no Jamaicans. Indications for transfusion also differed between the groups, Jamaican patients typically receiving 1-2 units for acute anaemia or acute chest syndrome, whereas UK patients frequently had multiple transfusions in preoperative exchange or prophylaxis programmes. The greater red cell alloimmunization among UK patients probably reflects both the greater use of transfusion and the disparity between donor and recipient populations in the UK.

Psychological distress and coping in sickle cell disease: comparison of British and Jamaican attitudes

OBJECTIVE

To investigate possible differences in coping mechanisms in the painful crisis between Jamaican and London patients with homozygous sickle cell disease.

DESIGN

Patients recruited from two London hospitals and the MRC Laboratories (Jamaica) at the University of the West Indies, Kingston, Jamaica were assessed using a questionnaire design. Patients with homozygous sickle cell disease were included, 30 in London and 30 in Jamaica.

RESULTS

Jamaican patients in Jamaica had less general anxiety, a lower emotional response to pain, lower levels of perceived pain, and felt better able to decrease their pain. London patients believed that the disease had a more marked effect on their quality of life.

CONCLUSION

Understanding the differences between patients' response to pain and their coping ability between Jamaican and UK patients may have important lessons for evolving effective management in the UK.

Day-care management of sickle cell painful crisis in Jamaica: a model applicable elsewhere?

In the U.K. and the U.S.A., painful crises account for 80-90% of sickle-related hospital admissions, with average durations of 5-11 d. In Jamaica, many severe painful crises are managed in a day-care centre. Patients (n=1160) with homozygous sickle cell (SS) disease aged 18 years and over were registered with the clinic during a 1-year study period. Of these, 216 patients with 476 painful crises attended the day-care facility for a total of 686 d. Most patients (119 or 55.1%) had single crises and for most crises (338 or 71%), patients attended for only 1 d, when they were given bed rest, assurance, rehydration and analgesia. Patients with complicated painful crises were usually referred for admission after initial pain relief and the rest were monitored during the day. In the evening they were given the option of hospital admission or allowed home with oral analgesia. Hospital admission for complicated painful crises or inadequate pain relief occurred in 42 (8.8%) crises and home management in 434 (91.2%) crises. Of 186 patients initially selecting home management, 20% returned for further day-care and five (2.7%) died during subsequent admission for that painful crisis, one without other known complications, two with acute chest syndrome (one associated with Salmonella septicaemia), another with Salmonella septicaemia, and one with dengue haemorrhagic fever. With suitable oral analgesia, adequate education and support, the majority of severe painful crises in SS disease in Jamaica have been managed on an outpatient basis. This model of patient care may merit assessment in other communities where painful crises are a common clinical problem.

Peripheral vascular response to mild indirect cooling in patients with homozygous sickle cell (SS) disease and the frequency of painful crisis

1. In homozygous sickle cell (SS) disease, skin cooling is a common precipitating factor of the painful crisis which is associated with avascular necrosis of active bone marrow. Since skin cooling does not directly induce sickling, we have investigated the nature of the reflex vascular responses to mild cooling in SS patients in a steady state of the disease and compared them with their history of painful crises. 2. Experiments were performed in Jamaica on 60 male SS patients and 30 matched control subjects with normal haemoglobin (AA) genotype. Forearm blood flow (FBF) was measured by venous occlusion plethysmography and mean arterial pressure (MAP) by a Finapres device: forearm vascular resistance (FVR) was calculated as MAP/FBF. Cutaneous erythrocyte flux in forearm and hand was monitored by a laser Doppler meter. The contralateral hand was immersed in cool water at 16 degrees C for 2 min, 6 times, at random intervals of 0.5-3 min. 3. The first cool immersion evoked an increase in MAP, cutaneous vasoconstriction and a net increase in FVR in both AA and SS subjects. However, the direction of change in FVR varied between individuals such that 18 AA subjects showed an increase in FVR (constrictor group) while 12 showed a decrease in FVR, indicating vasodilatation in forearm muscle (dilator group). In contrast, 50 SS subjects showed an increase in FVR and only 10 showed a decrease in FVR. The proportion of subjects who showed net vasoconstriction was significantly greater in the SS than in the AA group (83% versus 60%, P = 0.03, chi 2 test). 4. By the sixth cool stimulus, the 'dilator' group of AA subjects showed no change in FVR while the 'dilator' group of SS patients showed an increase in FVR. We suggest that forearm muscle vasodilatation was the characteristic component of the alerting/defence response to novel or noxious stimuli which habituates on repetition. 5. In the whole group of SS patients, baseline values of cutaneous vascular resistance and FVR increased between stimuli, indicating persistent vasoconstriction, and the sixth cool stimulus still evoked cutaneous vasoconstriction and a net increase in FVR. In contrast, AA subjects showed an increase in baseline FVR between stimuli, but the sixth cool stimulus had no significant effect on cutaneous vascular resistances, or FVR. 6. In SS patients there were no associations between the direction of change in FVR evoked by the first cool stimulus and forearm circumference or skinfold thickness, concentrations of haemoglobin or fetal haemoglobin. However, the frequency of painful crises was significantly greater in the 'constrictor' group than in the 'dilator' group (0.36 versus 0.12/year, P = 0.04, Mann-Whitney test). 7. These results indicate that the primary reflex vasoconstrictor response evoked by mild cooling is stronger and more persistent in SS patients than in AA subjects and is particularly strong in SS patients who are most prone to painful crises. The results are consistent with the hypothesis that skin cooling may precipitate the painful crisis by causing reflex vasoconstriction in muscle, and possibly in bone marrow, so diverting blood flow away from the active marrow.

Comparison of responses evoked by mild indirect cooling and by sound in the forearm vasculature in patients with homozygous sickle cell disease and in normal subjects

In normal individuals, novel or noxious stimuli commonly evoke the pattern of the alerting or defence response which includes cutaneous vasoconstriction, but vasodilatation in forearm skeletal muscle. We have compared cardiovascular responses evoked by sound and by indirect cooling in 60 patients with homozygous sickle cell (SS) disease and in 30 control subjects with normal haemoglobin genotype (AA). A sound of 90 dB, 1 kHz for 30s evoked an increase in hand and forearm cutaneous vascular resistance (HCVR and FCVR) in SS patients and an increase in HCVR in AA subjects, as assessed from Doppler flowmetry. Meanwhile, a decrease in forearm vascular resistance (FVR) assessed by venous occlusion plethysmography, occurred in 14 out of 30 AA subjects and 25 out of 60 SS patients, indicating vasodilatation in forearm muscle; an increase in FVR occurred in the remainder. The proportions of SS patients and AA subjects who showed an increase in FVR (53% vs 57%) were not significantly different. Cooling increased HCVR and FCVR in SS patients and increased FCVR in AA subjects; a decrease in FVR indicating vasodilatation, occurred in 12 out of 30 AA subjects, but in only 10 out of 60 SS patients. The proportion of SS patients who showed an increase in FVR to cooling was greater than in AA subjects (83% vs 60%, P < 0.05). Thus, SS patients are just as capable of showing the muscle vasodilatation of the alerting response to sound as AA subjects. That few SS patients showed muscle vasodilatation in response to cooling is consistent with the view that reflex vasoconstrictor responses to cooling are particularly strong in SS patients. This, in turn, is consistent with our hypothesis that the reflex vasoconstrictor response to cooling acts as a trigger for the painful crisis of SS disease by diverting blood flow away from active bone marrow.