Review of policy and status of implementation of collaborative HIV-TB activities in 23 high-burden countries

Issuance of national policy guidance is a critical step to ensure quality HIV-TB (human immunodeficiency virus-tuberculosis) coordination and programme implementation. From the database of the Joint United Nations Programme on HIV/AIDS (UNAIDS), we reviewed 62 national HIV and TB guidelines from 23 high-burden countries for recommendations on HIV testing for TB patients, criteria for initiating antiretroviral therapy (ART) and the Three I's for HIV/TB (isoniazid preventive treatment [IPT], intensified TB case finding and TB infection control). We used UNAIDS country-level programme data to determine the status of implementation of existing guidance. Of the 23 countries representing 89% of the global HIV-TB burden, Brazil recommends ART irrespective of CD4 count for all people living with HIV, and four (17%) countries recommend ART at the World Health Organization (WHO) 2013 guidelines level of CD4 count ⩿500 cells/mm(3) for asymptomatic persons. Nineteen (83%) countries are consistent with WHO 2013 guidelines and recommend ART for HIV-positive TB patients irrespective of CD4 count. IPT is recommended by 16 (70%) countries, representing 67% of the HIV-TB burden; 12 recommend symptom-based screening alone for IPT initiation. Guidelines from 15 (65%) countries with 79% of the world's HIV-TB burden include recommendations on HIV testing and counselling for TB patients. Although uptake of ART, HIV testing for TB patients, TB screening for people living with HIV and IPT have increased significantly, progress is still limited in many countries. There is considerable variance in the timing and content of national policies compared with WHO guidelines. Missed opportunities to implement new scientific evidence and delayed adaptation of existing WHO guidance remains a key challenge for many countries.

The epidemiology of HIV infection in Morocco: systematic review and data synthesis

Morocco has made significant strides in building its HIV research capacity. Based on a wealth of empirical data, the objective of this study was to conduct a comprehensive and systematic literature review and analytical synthesis of HIV epidemiological evidence in this country. Data were retrieved using three major sources of literature and data. HIV transmission dynamics were found to be focused in high-risk populations, with female sex workers (FSWs) and clients contributing the largest share of new HIV infections. There is a pattern of emerging epidemics among some high-risk populations, and some epidemics, particularly among FSWs, appear to be established and stable. The scale of the local HIV epidemics and populations affected show highly heterogeneous geographical distribution. To optimize the national HIV response, surveillance and prevention efforts need to be expanded among high-risk populations and in geographic settings where low intensity and possibly concentrated HIV epidemics are emerging or are already endemic.

Has the quality of serosurveillance in low- and middle-income countries improved since the last HIV estimates round in 2007? Status and trends through 2009

BACKGROUND

HIV surveillance systems aim to monitor trends of HIV infection, the geographical distribution and its magnitude, and the impact of HIV. The quality of HIV surveillance is a key element in determining the uncertainty ranges around HIV estimates. This paper aims to assess the quality of HIV surveillance systems in low- and middle-income countries in 2009 compared with 2007.

METHODS

Four dimensions related to the quality of surveillance systems are assessed: frequency and timeliness of data; appropriateness of populations; consistency of locations and groups; and representativeness of the groups. An algorithm for scoring the quality of surveillance systems was used separately for low and concentrated epidemics and for generalised epidemics.

RESULTS

The number of countries categorised as fully functioning in 2009 was 35, down from 40 in 2007. 47 countries were identified as partially functioning, while 56 were categorised as poorly functioning. When compared with 2007, the quality of HIV surveillance remains similar. The number of ANC sites in sub-Saharan Africa has increased over time. The number of countries with low and concentrated epidemics that do not have functioning HIV surveillance systems has increased from 53 to 56 between 2007 and 2009.

CONCLUSION

Overall, the quality of surveillance in low- and middle-income countries has remained stable. Still too many countries have poorly functioning surveillance systems. Several countries with generalised epidemics have conducted more than one population-based survey which can be used to confirm trends. In countries with concentrated or low-level epidemics, the lack of data on high-risk populations remains a challenge.

Oral mucosal lesions and HIV status in a rural household survey in South Africa

Several studies have documented the relevance of oral lesions in HIV populations. Oral HIV lesions are also considered useful indicators in HIV therapy. The objectives of the present study were to determine the prevalence of oral mucosal lesions (OML) in a rural population and to determine the differences, if any, in the prevalence of oral mucosal lesions of persons infected with HIV and persons not infected with HIV. The study was part of the Vaccine Preparedness Study (VPS) conducted by the Medical Research Council in Hlabisa, KwaZulu Natal, South Africa between 2000 and 2002.

METHODS

A cross-sectional household survey examined adults aged 15 to 50 years. Oral mucosal lesions were determined by a presumptive diagnosis. Informed consent was obtained for the oral examination and separately for collecting a blood sample to determine HIV status by ELISA.

RESULTS

A total of 2313 adults were interviewed for the VPS. Oral mucosal lesions were assessed in a sample comprising 537 adults. Of these, 185 consented to HIV testing and 22.7% (95% Confidence Interval (CI): 16.9-29.4%) were HIV positive. The prevalence of oral mucosal lesions in the total sample was 12.8% (95% CI: 10-16.3%). The prevalence of OML was 21.4% (9/42) among those who consented to a blood test and were HIV positive and 9.8% (n = 14/143) among those who were HIV negative.

CONCLUSION

The prevalence of OML among HIV positive participants was significantly higher than among HIV negative participants.

Progress and challenges in modelling country-level HIV/AIDS epidemics: the UNAIDS Estimation and Projection Package 2007

The UNAIDS Estimation and Projection Package (EPP) was developed to aid in country-level estimation and short-term projection of HIV/AIDS epidemics. This paper describes advances reflected in the most recent update of this tool (EPP 2007), and identifies key issues that remain to be addressed in future versions. The major change to EPP 2007 is the addition of uncertainty estimation for generalised epidemics using the technique of Bayesian melding, but many additional changes have been made to improve the user interface and efficiency of the package. This paper describes the interface for uncertainty analysis, changes to the user interface for calibration procedures and other user interface changes to improve EPP's utility in different settings. While formal uncertainty assessment remains an unresolved challenge in low-level and concentrated epidemics, the Bayesian melding approach has been applied to provide analysts in these settings with a visual depiction of the range of models that may be consistent with their data. In fitting the model to countries with longer-running epidemics in sub-Saharan Africa, a number of limitations have been identified in the current model with respect to accommodating behaviour change and accurately replicating certain observed epidemic patterns. This paper discusses these issues along with their implications for future changes to EPP and to the underlying UNAIDS Reference Group model.

The quality of sero-surveillance in low- and middle-income countries: status and trends through 2007

Objective:

To examine the quality of HIV sero-surveillance systems in 127 low-income and middle-income countries by 2007, as well as gaps in data needed for reliable estimates of HIV prevalence and size of populations at risk for infection.

Methods:

The quality of countries’ surveillance systems was scored using information from 2001 through 2007. Sero-surveillance data were compiled from the US Census Bureau’s HIV/AIDS Surveillance Database, from countries’ national HIV surveillance reports available to UNAIDS, from demographic and health survey (DHS) data, from the scientific literature and from countries’ Estimation and Projection Programme (EPP) data files. The quality of systems was scored according to the classification of the epidemic in each country (generalised, concentrated or low-level).

Result:

The number of countries categorised as fully functioning in 2007 was 40. 43 countries were identified as partially functioning while 44 were categorised as poorly functioning. Low scores were most often attributed to a lack of recent data or data from appropriate risk groups.

Conclusion:

Many countries still have poorly functioning surveillance systems. The inclusion of HIV testing in national population-based surveys in recent years has resulted in some countries with generalised epidemics receiving higher coverage scores, but many countries with concentrated or low-level epidemics continue to lack data on high-risk populations.

Comparison of adult HIV prevalence from national population-based surveys and antenatal clinic surveillance in countries with generalised epidemics: implications for calibrating surveillance data

Background:

Estimates of the impact of HIV in countries with generalised epidemics are generally based on antenatal clinic surveillance data collected over time. In an attempt to obtain geographically more representative estimates of HIV prevalence, many countries are now also conducting national population-based surveys in which HIV testing is included. We compare adult HIV prevalence estimates from antenatal clinic surveillance to those from national population-based surveys to assess the implications for calibrating surveillance data.

Methods:

HIV prevalence estimates derived from fitting prevalence curves to antenatal clinic surveillance data are statistically compared to prevalence from national population-based surveys using data from 26 countries with generalised epidemics for the year in which the survey was conducted. Appropriate transformations are applied to inform the correction factors needed to adjust prevalence in countries where population-based surveys have not been conducted.

Results:

HIV prevalence derived from antenatal clinic surveillance data generally overestimate population-based survey prevalence by about 20% (95% confidence interval: 10% to 30%) in both urban and rural areas.

Conclusions:

In countries where national population-based HIV surveys have been conducted, survey estimates of HIV prevalence (adjusted for potential survey biases as appropriate) can be used directly to calibrate antenatal clinic surveillance data. In countries where national HIV surveys have not been conducted, HIV prevalence derived from antenatal clinic surveillance data should be multiplied by about 0.8 to adjust for overestimation.

Improved plausibility bounds about the 2005 HIV and AIDS estimates

BACKGROUND

Since 1998 the Joint United Nations Programme on HIV/AIDS and the World Health Organization has provided estimates on the magnitude of the HIV epidemic for individual countries. Starting with the 2003 estimates, plausibility bounds about the estimates were also reported. The bounds are intended to serve as a guide as to what reasonable or plausible ranges are for the uncertainty in HIV incidence, prevalence, and mortality.

METHODS

Plausibility bounds were developed for three situations: for countries with generalised epidemics, for countries with low level or concentrated epidemics (LLC), and for regions. The techniques used build on those developed for the previous reporting round. However the current bounds are based on the available surveillance and survey data from each individual country rather than on data from a few prototypical countries.

RESULTS

The uncertainty around the HIV estimates depends on the quality of the surveillance system in the country. Countries with population based HIV seroprevalence surveys have the tightest plausibility bounds (average relative range about the adult HIV prevalence (ARR) of -18% to +19%.) Generalised epidemic countries without a survey have the next tightest ranges (average ARR of -46% to +59%). Those LLC countries which have conducted multiple surveys over time for HIV among the populations most at risk have the bounds similar to those in generalised epidemic countries (ARR -40% to +67%). As the number and quality of the studies in LLC countries goes down, the plausibility bounds increase (ARR of -38% to +102% for countries with medium quality data and ARR of -53% to +183% for countries with poor quality data). The plausibility bounds for regions directly reflect the bounds for the countries in those regions.

CONCLUSIONS

Although scientific, the plausibility bounds do not represent and should not be interpreted as formal statistical confidence intervals. However in order to make the bounds as meaningful as possible the authors have tried to apply reasonable statistical approaches and assumptions to their derivation. An understanding of the uncertainty in the HIV estimates may help policy makers take better informed decisions to address the epidemic in their respective countries.

National population based HIV prevalence surveys in sub-Saharan Africa: results and implications for HIV and AIDS estimates

BACKGROUND

Sentinel surveillance among pregnant women attending antenatal clinics (ANCs) has been the main source of information on HIV trends in sub-Saharan Africa. These data have also been used to generate national HIV and AIDS estimates. New technologies and resources have allowed many countries to conduct national population based surveys that include HIV prevalence measurement, as an additional source of information on the AIDS epidemic.

METHODS

The authors reviewed the reports of 20 national population based surveys from 19 countries carried out in sub-Saharan Africa since 2001. They examined the sampling methodology, HIV testing and response rates, and female:male and urban:rural prevalence ratios. They also constructed adjusted prevalence scenarios assuming different relative risks for survey non-responders.

RESULTS

The national population based surveys vary considerably in quality, as reflected in the household response rate (ranging from 75.4% to 99.7%), women's testing rate (ranging from 68.2% to 97.3%), and men's testing rate (ranging from 62.2% to 95.4%), while for some surveys detailed response information is lacking. While 95% confidence intervals around the female:male and urban:rural prevalence ratios in individual countries are large, the median female:male ratio of the combined set of surveys results is 1.5 and the median urban:rural ratio 1.7. A scenario assuming that non-responders have twice the HIV prevalence of those who fully participated in the survey suggests that individual non-response could result in an adjusted HIV prevalence 1.03 to 1.34 times higher than the observed prevalence.

CONCLUSIONS

Population based surveys can provide useful information on HIV prevalence levels and distribution. This information is being used to improve national HIV and AIDS estimates. Further refinements in data collection, analysis, and reporting, combined with high participation rates, can further improve HIV and AIDS estimates at national and regional level.

The 2005 Workbook: an improved tool for estimating HIV prevalence in countries with low level and concentrated epidemics

OBJECTIVE

This paper describes improvements and updates to an established approach to making epidemiological estimates of HIV prevalence in countries with low level and concentrated epidemics.

METHODS

The structure of the software used to make estimates is briefly described, with particular attention to changes and improvements.

DISCUSSION

The approach focuses on identifying populations which, through their behaviour, are at high risk of infection with HIV or who are exposed through the risk behaviour of their sexual partners. Estimates of size and HIV prevalence of these populations allow the total number of HIV infected people in a country or region to be estimated. Major changes in the software focus on the move away from short term projections and towards developing an epidemiological curve that more accurately represents the change in prevalence of HIV over time. The software continues to provide an output file for use in the Spectrum software so as to estimate the demographic impact of HIV infection at country level.

Short term estimates of adult HIV incidence by mode of transmission: Kenya and Thailand as examples

OBJECTIVE

Patterns of transmission of HIV are different among different regions of the world and change over time within regions. In order to adapt prevention strategies to changing patterns of risk, we need to understand the behaviours that put people at risk of infection and how new infections are distributed among risk groups.

METHODS

A model is described to calculate the expected incidence of HIV infections in the adult population by mode of exposure using the current distribution of prevalent infections and the patterns of risk within different populations. For illustration the model is applied to Thailand and Kenya.

RESULTS

New infections in Kenya were mainly transmitted through heterosexual contact (90%), while a small but significant number were related to injecting drug use (4.8%) and men who have sex with men (4.5%). In Thailand, the epidemic has spread over time to the sexual partners of vulnerable groups and in 2005 the majority of new infections occurred among the low risk heterosexual population (43%). Men having sex with men accounted for 21% and sex work (including sex workers, clients, and partners of clients) for 18% of new infections. Medical interventions did not contribute significantly to new infections in either Kenya or Thailand.

CONCLUSIONS

The model provides a simple tool to inform the planning of effective, appropriately targeted, country specific intervention programmes. However, better surveillance systems are needed in countries to obtain more reliable biological and behavioural data in order to improve the estimates of incidence by risk group.

Early sexual debut among young men in rural South Africa: heightened vulnerability to sexual risk?

OBJECTIVE

This report examines early sexual debut (<age 15) among young men in rural South Africa including (1) risk behaviours at first sexual experience, and (2) age at first sex as a predictor of later sexual risk.

METHODS

Analysis of sexual behaviour data for men 15-24 years (n = 314) from representative cross sectional household survey.

RESULTS

13.1% of 15-24 year old men experienced sexual debut before age 15. Men with sexual debut at less than age 15 were more likely to report risk behaviours at first sexual experience: no condom use (19%), a casual partner (26.8%), and not feeling they had been "ready and wanted to have sex" (19.5%). In multivariate analysis, early sexual debut was strongly associated with > or = 3 partners in the past 3 years (OR = 10.26, p<0.01).

CONCLUSIONS

Men who initiate sex before age 15 form a distinct risk group in this setting. Specific interventions are needed for young men in the pre-teen years, before sexual debut.

Thromboelastography in abruptio placentae

The purpose of this study was to document thromboelastographic (TEG) changes in abruptio placentae and to compare these results with that of conventional tests used to monitor coagulation. This was a prospective study of 30 patients with abruptio placentae. All coagulation investigations including the TEG were performed on admission, immediately following delivery, and after periods of 4 hours and 24 hours. Results showed that standard coagulation tests detected coagulation abnormalities except the platelet count returned to normal limits within 24 hours of delivery. There was strong correlation between fibrinogen levels and the TEG parameters, ma and k time (r=0.8). There was moderate correlation between platelet count and ma (r=0.6). In conclusion, minor abnormalities in the clotting profile are clinically unimportant. The TEG does not detect such minor abnormalities because of its inherent ability to test the coagulation cascade as a whole. Major abnormalities are clinically relevant and the TEG detect 75% of them. Further, the TEG establishes the diagnosis of hypercoagulability an early sign of disseminated intravascular coagulation. Although standard laboratory tests are still necessary to detect coagulation abnormalities on admission, the TEG is a useful test in large obstetric units where laboratory results are not immediately available for the purposes of monitoring and treating ongoing coagulation defects.

Quality of care for under-fives in first-level health facilities in one district of Bangladesh

OBJECTIVE

The multi-country evaluation of Integrated Management of Childhood Illness (IMCI) effectiveness, cost and impact (MCE) is a global evaluation to determine the impact of IMCI on health outcomes and its cost-effectiveness. MCE studies are under way in Bangladesh, Brazil, Peru, Uganda and the United Republic of Tanzania. The objective of this analysis from the Bangladesh MCE study was to describe the quality of care delivered to sick children under 5 years old in first-level government health facilities, to inform government planning of child health programmes.

METHODS

Generic MCE Health Facility Survey tools were adapted, translated and pre-tested. Medical doctors trained in IMCI and these tools conducted the survey in all 19 health facilities in the study areas. The data were collected using observations, exit interviews, inventories and interviews with facility providers.

FINDINGS

Few of the sick children seeking care at these facilities were fully assessed or correctly treated, and almost none of their caregivers were advised on how to continue the care of the child at home. Over one-third of the sick children whose care was observed were managed by lower-level workers who were significantly more likely than higher-level workers to classify the sick child correctly and to provide correct information on home care to the caregiver.

CONCLUSION

These results demonstrate an urgent need for interventions to improve the quality of care provided for sick children in first-level facilities in Bangladesh, and suggest that including lower-level workers as targets for IMCI case-management training may be beneficial. The findings suggest that the IMCI strategy offers a promising set of interventions to address the child health service problems in Bangladesh.

Hookworm (Necator americanus) transmission in inland areas of sandy soils in KwaZulu-Natal, South Africa

This study extended the association between hookworm transmission in KwaZulu-Natal and the sandy coastal plain by investigating the parasite's occurrence in isolated areas of sandy soils further inland. A school-based prevalence survey was carried out in selected inland sandy areas and in surrounding areas dominated by clay soils within a narrow altitudinal range of between 500 and 700 m to reduce the effect of altitude on climate-related factors (rainfall and temperature). Sandy areas situated on the coastal plain were included in the analysis for comparative purposes. Soil samples (0-50 mm depth) were collected from each locality to assess their nematode loadings and to analyse selected physical and chemical properties. Significant differences were found between the moderate prevalence of hookworm infection among children living in inland areas with sandy soils (17.3%) and the low prevalence in surrounding non-sandy areas (5.3%, P < 0.001), and between infection among children living in all inland areas (9.3%) and the high prevalence on the coastal plain (62.5%, P < 0.001). Amounts of fine and medium sand were highest in both the coastal plain soils and in inland sandy areas and these fractions showed a significant positive correlation with hookworm prevalence and nematode loadings. Clay, coarse sand and organic matter contents were highest in surrounding non-sandy soils and showed a significant negative correlation with the nematode variables. No statistically significant correlations were found with soil pH at study localities. We conclude that properties of inland sandy soils, particularly particle size distribution, correlate well with hookworm prevalence and nematode loadings and therefore provide a more suitable habitat for nematodes than surrounding non-sandy areas. These results suggest that particle size distribution of sand fractions, organic matter and clay content in the soil influence the survival of hookworm larvae and hence the parasite's transmission.

Risk factors for HIV infection among women in Carletonville, South Africa: migration, demography and sexually transmitted diseases

We investigate the prevalence of, and risk factors for, HIV infection among women in an urban South African setting. A random sample of 834 women was recruited into a community-based cross-sectional study. HIV prevalence was 37.1% with higher prevalence among migrant women (46.0%) than non-migrant women (34.7%), (odds ratio [OR]=1.61, 95% confidence interval [CI]: 1.11-2.31). The highest HIV prevalence (50.9%) was between ages 26 and 35 years. Having two or more lifetime partners increased the risk of HIV infection (OR=4.88, 95% CI: 3.01-7.89). Migration, age, marital status, alcohol use, syphilis and gonorrhoea were independently associated with HIV infection. Migration increases the risk of HIV infection. Provision of services to treat sexually transmitted diseases and educational empowerment programmes that will promote safer sex among migrant women are urgently needed.

The effect of soil type and climate on hookworm (Necator americanus) distribution in KwaZulu-Natal, South Africa

We investigated environmental factors influencing the distribution of hookworm infection in KwaZulu-Natal, South Africa. Prevalence data were sourced from previous studies and additional surveys carried out to supplement the database. When geo-referenced the data revealed that higher prevalences are limited to areas below 150 m above sea level, and low prevalences to areas above this altitude. Using univariate analysis we investigated the differences in environmental factors in the two areas. The relationship between hookworm prevalence, altitude and climate-derived variables was assessed using Pearson correlation coefficient, and that of soil type using the t-test. Multivariate analysis was used to determine environmental factors that combine best to provide favourable conditions for hookworm distribution. The results revealed that areas <or=150 m above sea level, i.e. the coastal plain, supported high prevalences (x = 45, n = 51), and were characterized by sandy soils with a clay content of less than 15%, warm temperatures and relatively high rainfall. Areas >150 m above sea level, i.e. inland, supported low mean hookworm prevalences (x = 6, n = 21), and were characterized by soils with a clay content of more than 45%, variable temperatures and moderate rainfall. Hookworm prevalence also decreased southwards as temperatures became slightly cooler, rainfall remained more-or-less constant and the coastal plain narrowed. In the multivariate model prevalence was most significantly correlated with the mean daily minimum temperature for January followed by the mean number of rainy days for January. This indicates the importance of summer conditions in the transmission of hookworm infection in KwaZulu-Natal and suggests that transmission may be seasonal.

High incidence of Type 2 diabetes mellitus in South African Indians: a 10-year follow-up study

AIMS

Previous cross-sectional studies have established that South African Indians have a high prevalence of Type 2 diabetes mellitus. A prospective community study was undertaken to determine the incidence of Type 2 diabetes and the risk factors associated with its development in a cohort of South African Indians who had been studied 10 years previously.

METHODS

This is a report on 563 subjects who participated both at baseline and at the 10-year follow-up study. In the baseline study, 2479 subjects (> 15 years) were studied; using 1985 World Health Organization criteria for glucose tolerance based on 75 g oral glucose tolerance tests (OGTT), the crude prevalence of diabetes mellitus (Diabetes) was 9.8% and of impaired glucose tolerance (IGT) 5.8% (age and sex-adjusted prevalence 13% and 6.9%, respectively).

RESULTS

At the 10-year follow-up study, 563 of the subjects who could be traced consented to a repeat OGTT; of these, 91 (16.2%) were classified as Diabetes and 41 (7.3%) as IGT. Of the subjects who did not have diabetes at baseline (n = 517), 49 (9.5%) progressed to diabetes (PTD) and 40 (7.7%) had IGT. The crude cumulative incidence of diabetes was 9.5% (rate of progression 0.95% per annum; incidence density 9.5/1000 person years) with an age and sex-adjusted cumulative incidence of 8.3% (rate of progression 0.95% per annum; incidence density 8.3/1000 person years). Examination of risk factors predictive of subsequent diabetes development was undertaken by analysis of baseline (year 0) variables in the 517 subjects who did not have diabetes at baseline. In multivariate analysis using a logistic regression model, the significant predictive risk factors for future diabetes included 2-h post load plasma glucose (2 PG) (P < 0.0001, odds ratio (OR) 1.7, 95% confidence interval (CI) 1.4-2.1), body mass index (BMI) (P < 0.006, OR 1.1, 95% CI 1.0-1.3) and obesity (P < 0.01, OR 4.6, 95% CI 1.4-14.7).

CONCLUSIONS

This long-term study has shown that in South African Indians there is a high incidence of Type 2 diabetes, and in this population significant predictors include higher baseline blood glucose, BMI and obesity.

Microvascular complications in South African patients with long-duration diabetes mellitus

OBJECTIVE

To determine the prevalence of microvascular complications in South African black and Indian patients with long-duration diabetes mellitus (DM).

DESIGN

A retrospective analysis was undertaken of clinical records of 219 DM patients (132 black, 87 Indian) with long-duration DM (over 10 years) attending a diabetes clinic in Durban. Data recorded on each subject included demographic details (age, gender, ethnic group, type of diabetes, age of onset and duration of diabetes), presence of retinopathy, markers of nephropathy and biochemical variables. The prevalence of complications and the clinical and biochemical parameters were evaluated for type 1 and type 2 diabetes and for each ethnic group.

RESULTS

Of the 219 patients, 47 had type 1 DM (36 blacks, 11 Indians) and 172 were classified as type 2 DM (96 blacks, 76 Indians). The mean age of onset of DM was later in blacks than Indians, both for type 1 (P < 0.05) and type 2 DM (P < 0.01). In patients with type 1 DM, the prevalence of retinopathy was 53.2% (blacks 55.6%, Indians 45.5%), persistent proteinuria was found in 23.4% (blacks 25%, Indians 18.2%) and hypertension in 34%. No ethnic difference was found except for the prevalence of hypertension which was higher in blacks than Indians (41.7% v. 9.1%, P < 0.5). Onset of retinopathy from time of diabetes diagnosis occurred earlier in blacks than Indians (13.0 +/- 4.6 yrs v. 18.0 +/- 4.6 yrs, P < 0.05). For the type 2 DM group, retinopathy was found in 64.5% (black v. Indian 68.8 v. 59.2%) and persistent proteinuria in 25% (black v. Indian 30.2 v. 18.4%). Hypertension was observed in 68% and was more prevalent in blacks (84.4 v. 47.4%, P < 0.01) There was an earlier onset of retinopathy (P < 0.05) and hypertension (P < 0.01) from time of diabetes diagnosis in blacks than Indians. In the type 1 DM group retinopathy was associated with a significantly longer duration of diabetes (P < 0.05) and higher glycated haemoglobin (HbA1) (P < 0.05). For type 2 DM subjects there was a significant association between retinopathy and longer duration of diabetes (P < 0.05) and higher systolic blood pressure (P < 0.05).

CONCLUSION

This study has shown that there is a high prevalence of microvascular complications in South African patients with long-duration diabetes mellitus.

Craniotomy improves outcomes for cranial subdural empyemas: computed tomography-era experience with 699 patients

OBJECTIVE

Uncertainty regarding the best surgical management for subdural empyemas (SDEs) continues. Our unit has considered craniotomy the preferred method of surgical drainage for all cranial SDEs since 1988. We performed an analysis of our previously published, computed tomography-era, experience with 699 patients.

METHODS

Two analyses of the database (1983-1997) were performed. First, analysis of the periods from 1983 to 1987 and from 1988 to 1997 was performed. Second, analysis of the composite database was performed. Outcomes were compared for possible outcome predictors by univariate analysis. Multivariate analysis was used to identify variables that contributed independently to outcomes, using stepwise discriminant analysis.

RESULTS

Significant correlations between the analyzed periods with respect to outcome and type of surgery (P = 0.001) were noted. Analysis of the entire database (1983-1997) revealed a significant relationship between outcome and surgery type (P = 0.05). Pairwise comparison of limited procedures such as burr holes or craniectomies with wide-exposure surgical procedures such as primary craniotomies or procedures proceeding to full craniotomies indicated significant correlation with outcomes (P = 0.027). Reoperation and morbidity rates were increased with limited procedures. Stepwise discriminant analyses revealed that the type of surgery was correlated with outcomes (P = 0.0008, partial r(2) = 0.034).

CONCLUSION

Craniotomy was determined to be the surgical procedure of choice for treatment of cranial SDEs, allowing complete evacuation of the pus and, more importantly, decompressing the underlying cerebral hemisphere. Limited procedures such as burr holes or craniectomies may be performed for patients in septic shock, for patients with parafalcine empyemas, or for children with SDEs secondary to meningitis.

Growth in early childhood in a cohort of children born to HIV-1-infected women from Durban, South Africa

This study describes growth in a cohort of black South African children born to HIV-1-infected women in Durban. Children born to HIV-1-seropositive women were followed up from birth to early childhood. At birth and at each visit, growth parameters were measured. Mean Z-scores were calculated for weight-for-length, weight-for-age and length-for-age and, if they were low, the children were regarded as wasted, malnourished or stunted, respectively. At the end of the study, there were 48 infected and 93 uninfected children. There were no significant differences between the two groups at birth. Thereafter, the infected group was found to have early and sustained low mean Z-scores for length-for-age and weight-for-age but not for weight-for-length. The means reached significance at ages 3, 6 and 12 months for length and at 3, 6 and 9 months for weight. Infected children who died early had more severe stunting, wasting and malnutrition than infected children who survived. Infected children born to HIV-positive women have early and sustained stunting and are malnourished but not wasted. Children with rapidly progressive disease have both stunting and wasting and are more severely affected. Early nutritional intervention might help prevent early progression or death in HIV-infected children, particularly in developing countries without access to anti-retroviral therapy in state hospitals.

The epidemiology of human immunodeficiency virus in South Africa

We review the epidemiology of human immunodeficiency virus (HIV) in South Africa where the prevalence of HIV infection is among the highest in the world. The epidemic reached South Africa relatively recently but the prevalence of infection has increased rapidly and there are significant differences among provinces. Although few 15-year-old people are infected the prevalence increases rapidly with age thereafter, especially among women. The prevalence of herpes simplex virus type 2 exceeds that of HIV and curable sexually transmitted infections are common. 'Circular migration' may help to explain the high rates and rapid spread of HIV in the region. The incidence of tuberculosis has increased dramatically as a result of the HIV epidemic. Antiretroviral therapy for the prevention of vertical transmission has been shown to be effective in local conditions but transmission through breast-feeding remains problematical. While some epidemiological models have been developed, much more needs to be done in this regard in order to plan, coordinate and evaluate an effective response to the epidemic. We conclude by discussing some of the research that is needed and steps that could be taken to reduce the continued spread of the infection.

Estimating HIV incidence rates from age prevalence data in epidemic situations

We present a method of estimating HIV incidence rates in epidemic situations from data on age-specific prevalence and changes in the overall prevalence over time. The method is applied to women attending antenatal clinics in Hlabisa, a rural district of KwaZulu/Natal, South Africa, where transmission of HIV is overwhelmingly through heterosexual contact. A model which gives age-specific prevalence rates in the presence of a progressing epidemic is fitted to prevalence data for 1998 using maximum likelihood methods and used to derive the age-specific incidence. Error estimates are obtained using a Monte Carlo procedure. Although the method is quite general some simplifying assumptions are made concerning the form of the risk function and sensitivity analyses are performed to explore the importance of these assumptions. The analysis shows that in 1998 the annual incidence of infection per susceptible woman increased from 5.4 per cent (3.3-8.5 per cent; here and elsewhere ranges give 95 per cent confidence limits) at age 15 years to 24.5 per cent (20.6-29.1 per cent) at age 22 years and declined to 1.3 per cent (0.5-2.9 per cent) at age 50 years; standardized to a uniform age distribution, the overall incidence per susceptible woman aged 15 to 59 was 11.4 per cent (10.0-13.1 per cent); per women in the population it was 8.4 per cent (7.3-9.5 per cent). Standardized to the age distribution of the female population the average incidence per woman was 9.6 per cent (8.4-11.0 per cent); standardized to the age distribution of women attending antenatal clinics, it was 11.3 per cent (9.8-13.3 per cent). The estimated incidence depends on the values used for the epidemic growth rate and the AIDS related mortality. To ensure that, for this population, errors in these two parameters change the age specific estimates of the annual incidence by less than the standard deviation of the estimates of the age specific incidence, the AIDS related mortality should be known to within +/-50 per cent and the epidemic growth rate to within +/-25 per cent, both of which conditions are met. In the absence of cohort studies to measure the incidence of HIV infection directly, useful estimates of the age-specific incidence can be obtained from cross-sectional, age-specific prevalence data and repeat cross-sectional data on the overall prevalence of HIV infection. Several assumptions were made because of the lack of data but sensitivity analyses show that they are unlikely to affect the overall estimates significantly. These estimates are important in assessing the magnitude of the public health problem, for designing vaccine trials and for evaluating the impact of interventions.

HIV infection among youth in a South African mining town is associated with herpes simplex virus-2 seropositivity and sexual behaviour

OBJECTIVES

To determine the seroprevalence of HIV and herpes simplex virus-2 (HSV-2) by age and gender among young people aged 14--24 years in a South African town and to identify risk factors for HIV infection.

DESIGN

A community-based, cross-sectional study was conducted on a random sample of men (n = 723) and women (n = 784) living in a township in the Carletonville district of South Africa.

METHODS

Potential demographic and behavioural risk factors associated with HIV were recorded by questionnaire and biological tests were performed on serum and urine. Data analysis was performed using multivariate logistic regression.

RESULTS

Among men and women the prevalence of HIV infection was 9.4 and 34.4%, respectively, and of positive HSV-2 serology was 17.0 and 53.3%, respectively. Among 24-year-old women the prevalence of HIV was 66.7% [95% confidence interval (CI), 54.6--77.3%]. HSV-2 seropositivity was a strong independent risk factor for HIV infection with odds ratios of 5.3 (95% CI, 2.7--10.3) for men and 8.4 (95% CI, 4.9--14.2) for women. There was no independent effect of age at first sex or serological markers of other sexually transmitted infections on HIV infection.

CONCLUSIONS

HIV infection among young women increases rapidly after the onset of sexual activity and reaches extremely high levels by 24 years of age. These findings suggest that rates of HIV transmission from men to women are high and that HSV-2 plays a major role in the spread of HIV in this population.

Effect of removing user fees on attendance for curative and preventive primary health care services in rural South Africa

User fees are used to recover costs and discourage unnecessary attendance at primary care clinics in many developing countries. In South Africa, user fees for children aged under 6 years and pregnant women were removed in 1994, and in 1997 all user fees at all primary health care clinics were abolished. The intention of these policy changes was to improve access to health services for previously disadvantaged communities. We investigated the impact of these changes on clinic attendance patterns in Hlabisa health district. Average quarterly new registrations and total attendances for preventive services (antenatal care, immunization, growth monitoring) and curative services (treatment of ailments) at a mobile primary health care unit were studied from 1992 to 1998. Regression analysis was undertaken to assess whether trends were statistically significant. There was a sustained increase in new registrations (P = 0.0001) and total attendances (P = 0.0001) for curative services, and a fall in new registrations (P = 0.01) and total attendances for immunization and growth monitoring (P = 0.0002) over the study period. The upturn in demand for curative services started at the time of the first policy change. The decreases in antenatal registrations (P = 0.07) and attendances (P = 0.09) were not statistically significant. The number of new registrations for immunization and growth monitoring increased following the first policy change but declined thereafter. We found no evidence that the second policy change influenced underlying trends. The removal of user fees improved access to curative services but this may have happened at the expense of some preventive services. Governments should remain vigilant about the effects of new health policies in order to ensure that objectives are being met.

Transcranial brainstem stab injuries: a retrospective analysis of 17 patients

OBJECTIVE

Transcranial stab injuries remain a frequent cause of emergent neurosurgical admissions to neurosurgical units in South Africa. Brainstem stabs are an uncommon, yet often fatal, form of brain injury.

METHODS

A retrospective audit of 597 patients with transcranial stab injuries admitted to our unit over a 12-year period (January 1987 to December 1998) identified 17 patients (2.85%) with brainstem stab injuries. The computed tomographic scans of all patients were analyzed, and a detailed autopsy examination of the skull and its contents was performed in all patients who died. Stepwise linear regression analysis was used to formulate a predictive model of outcome for the entire series of 597 patients.

RESULTS

The majority of the patients were males (16 patients), and the study group had a mean age of 28.65 +/- 9.59 years and a mean Glasgow Coma Scale score of 8.59 +/- 2.76. Knives (82%) were the most common instruments of penetration. Cerebral angiography identified 3 patients with vascular abnormalities, and autopsy revealed an additional 4 patients with vascular injury. Emergency ventriculostomy was performed in 10 patients for obstructive hydrocephalus. Four of the 17 patients survived (76.5% mortality). Factors significantly predictive of outcome in patients with transcranial stab injuries were the Glasgow Coma Scale score (F = 43.7), the occurrence of intraventricular hemorrhage (F = 22.8), the type of associated lesion (intracranial bleed, vascular abnormality, or brain abscess) (F = 5.9), and the number of operations (F = 3.2).

CONCLUSION

The Glasgow Coma Scale score is the most significant predictor of outcome in low-velocity transcranial stab injuries. Brainstem stab injuries have a great propensity for vascular damage. Survivors are incapacitated by severe, fixed neurological deficits.

Cerebral blood flow changes in rhinogenic subdural empyema and the role of hyperaemia in brain swelling

BACKGROUND

Previous studies have demonstrated that rhinogenic subdural empyema (SDE) generally has a good prognosis. Most patients are admitted with an altered level of consciousness or significant neurological deficit, but eventually have a good outcome. It is well known that intra-operative brain swelling may occur with subdural empyema.

OBJECTIVE

To define cerebral blood flow (CBF) dynamics and determine the role of cerebral hyperaemia, if any, in intracranial SDE.

METHODS

CBF dynamics were assessed in five patients (mean age 13.2 +/- 2.2 years) with unilateral rhinogenic convexity SDE documented on computer tomography (CT). Regional cortical blood flow (rCBF) was measured using a thermo-coupled sensor placed on the cortex at the time of surgery. Dynamic CT scans were performed to assess cerebral blood volume (CBV) quantitatively, while transcranial Doppler ultrasonography (TCD) was used to measure cerebral blood flow velocities (CBF velocities) both pre- and post-operatively for 21 days. The opposite 'normal' hemisphere served as a control for each patient.

RESULTS

Post-operative rCBF and CBF velocities in the pathological hemisphere progressively increased to plateau at 96 hours. Cerebral blood volume was increased bilaterally, but to a greater extent in the pathological hemisphere and more so in grey than white matter. These haemodynamic changes, though clinically significant did not reach statistical significance (p>0.05).

CONCLUSION

Our results suggest that the accompanying brain swelling in rhinogenic SDE is a complex event, with reactive cerebral hyperaemia possibly playing neuroprotective role. Furthermore, unilateral convexity empyema causes bilateral cerebral haemodynamic changes. Future studies are necessary to define the aetiology of brain swelling in intracranial SDE.

High HIV incidence and prevalence among young women in rural South Africa: developing a cohort for intervention trials

OBJECTIVE

To measure prevalence and model incidence of HIV infection.

SETTING

2013 consecutive pregnant women attending public sector antenatal clinics in 1997 in Hlabisa health district, South Africa. Historical seroprevalence data, 1992-1995.

METHODS

Serum remaining from syphilis testing was tested anonymously for antibodies to HIV to determine seroprevalence. Two models, allowing for differential mortality between HIV-positive and HIV-negative people, were used. The first used serial seroprevalence data to estimate trends in annual incidence. The second, a maximum likelihood model, took account of changing force of infection and age-dependent risk of infection, to estimate age-specific HIV incidence in 1997. Multiple logistic regression provided adjusted odds ratios (OR) for risk factors for prevalent HIV infection.

RESULTS

Estimated annual HIV incidence increased from 4% in 1992/1993 to 10% in 1996/1997. In 1997, highest age-specific incidence was 16% among women aged between 20 and 24 years. In 1997, overall prevalence was 26% (95% confidence interval [CI], 24%-28%) and at 34% was highest among women aged between 20 and 24 years. Young age (<30 years; odds ratio [OR], 2.1; p = .001), unmarried status (OR 2.2; p = .001) and living in less remote parts of the district (OR 1.5; p = .002) were associated with HIV prevalence in univariate analysis. Associations were less strong in multivariate analysis. Partner's migration status was not associated with HIV infection. Substantial heterogeneity of HIV prevalence by clinic was observed (range 17%-31%; test for trend, p = .001).

CONCLUSIONS

This community is experiencing an explosive HIV epidemic. Young, single women in the more developed parts of the district would form an appropriate cohort to test, and benefit from, interventions such as vaginal microbicides and HIV vaccines.

The distribution of helminth infections along the coastal plain of Kwazulu-Natal province, South Africa

The results of a previous study indicated that, in the province of KwaZulu-Natal, South Africa, Necator americanus and Strongyloides stercoralis were endemic to the coastal lowlands only. The prevalences of these helminths, as well as those of Trichuris trichiura and Ascaris lumbricoides, have now been investigated along a 1000-km-long transect through the coastal plain, at altitudes of < 300 m, from the Mozambique border (26 degrees 57'S) to the border with Eastern Cape province (30 degrees 53'S). Necator americanus was by far the most dominant hookworm species. Although prevalences of N. americanus and S. stercoralis infection decreased with increasing southerly latitude, those of T. trichiura and A. lumbricoides did not. Determinants of these distribution patterns are examined in terms of a suite of temperature- and rainfall-related variables.

GB virus C/hepatitis G virus infection in KwaZulu Natal, South Africa

Sera from 70 patients on maintenance haemodialysis, 98 patients with chronic liver disease, and 232 volunteer blood donors in the province of KwaZulu Natal, South Africa, were screened for GB virus/hepatitis G virus (GBV-C/HGV) RNA and anti-E2 by reverse transcription-polymerase chain reaction (RT-PCR) and by an enzyme-linked immunosorbent assay (ELISA), respectively. GBV-C/HGV RNA was detected in 17/70 (24.3%) haemodialysis patients, 12/98 (12.2%) patients with chronic liver disease, and 44/232 (18.9%) blood donors (Africans [29/76; 38.2%]; Asians [2/52; 3.8%]; Whites [11/49; 22.4%], and "Coloureds" [persons of mixed origin; 2/55; 3.6%]). Overall (anti-E2 and/or RNA) 43.9% (43/98) of patients with chronic liver disease, 47.1% (33/70) of haemodialysis patients, and 31.9% (74/232) of blood donors (Africans [44/76; 5.9%]; Asians [5/52; 9.6%]; Whites [15/49; 30.6%], and Coloureds [9/54; 16.6%]) were exposed to GBV-C/HGV infection. There was a significant difference in the prevalence of GBV-C/HGV infection (RNA and/or anti-E2) between African blood donors and the other racial groups (P < .001), and between blood donors and haemodialysis patients (P = .02) and patients with chronic liver disease (P = .04). Anti-E2 antibodies and GBV-C/HGV RNA were almost mutually exclusive. GBV-C/HGV-infected haemodialysis patients received more transfusions (P = .03) than noninfected patients. There was no significant difference in liver biochemistry between GBV-C/HGV-infected and noninfected patients and between blood donors in each of the four racial groups. The high prevalence of GBV-C/HGV infection in blood donors and chronic liver disease patients, and the lack of elevated liver enzymes and clinical hepatitis in blood donors and haemodialysis patients, suggest that GBV-C/HGV may not be associated with liver disease.

Pregnancy outcome in primigravidae with late onset hypertensive disease

BACKGROUND

The perinatal mortality associated with pre-eclampsia is extremely high and it is mainly associated with early onset disease in multiparous women. Hypertension without proteinuria in late pregnancy may not be associated with high perinatal mortality rates.

OBJECTIVE

To establish the perinatal outcome in primigravidae women with hypertension occurring in late pregnancy, that is, at thirty fourth week or later.

DESIGN

Prospective case-control study.

SETTING

Labour ward of King Edward VIII Hospital, Durban, South Africa.

PATIENTS

Three hundred and twenty two primigravidae consisting of 161 hypertensives and 161 controls.

MAIN OUTCOME MEASURES

Maternal and foetal morbidity and mortality.

RESULTS

The hypertensive group was divided into those with proteinuria (group a) and without proteinuria (group b). The mean birthweight of babies born to proteinuric hypertensives was significantly lower than that of hypertensives without proteinuria and the normotensive group (2.4 kg (a) versus 2.8 kg (b) versus 3.02 kg (c) respectively--a versus b, p = 0.0001; a versus c, p = 0.001; b versus c, p = 0.009). There were nine perinatal deaths and all occurred in the proteinuric hypertension group.

CONCLUSION

Primigravidae with late onset proteinuric hypertension had smaller babies and higher perinatal mortality than their aproteinuric hypertensive and normotensive controls.

Intracranial subdural empyemas in the era of computed tomography: a review of 699 cases

OBJECTIVE

Intracranial empyemas are the most common form of intracranial suppuration seen in our unit and, despite modern antibiotic therapy and advanced neurosurgical and imaging facilities, these pus collections remain a formidable challenge, often resulting in significant morbidity and death. We present an analysis of our 15-year experience with this condition in the era of computed tomography.

METHODS

A retrospective analysis of 4623 patients admitted with intracranial sepsis during a 15-year period (1983-1997) identified 699 patients with intracranial subdural empyemas. The inpatient notes for these patients were analyzed with respect to clinical, radiological, bacteriological, surgical, and outcome data. Statistical analyses were performed.

RESULTS

The 699 intracranial subdural empyemas accounted for 15% of all admissions for intracranial sepsis during the study period. Young male patients in the second or third decade of life were most commonly affected (62%), and the mean age was 14.65+/-12.2 years. Almost all patients (96%) underwent surgery. Eighty-two percent of patients experienced good outcomes (Glasgow Outcome Scale scores of 4 or 5). A morbidity rate of 25.9% (including postoperative seizures) was noted, and 85 patients died (mortality rate, 12.2%).

CONCLUSION

Intracranial subdural empyema, which is a neurosurgical emergency, is rapidly fatal if not recognized early and managed promptly. Early surgical drainage, simultaneous eradication of the primary source of sepsis, and intravenous administration of high doses of appropriate antibiotic agents represent the mainstays of treatment.

Elevated adenosine deaminase activity in patients with HIV and tuberculous peritonitis

OBJECTIVE

To evaluate the diagnostic potential of the ADA(T), ADA isoenzymes (ADA1 and ADA2) and the interferon-gamma (IFN-gamma) test in HIV-seropositive patients with tuberculous peritonitis.

METHODS

Ascitic ADA(T), ADA1, ADA2 and IFN-gamma were prospectively evaluated in HIV-seronegative patients with tuberculous peritonitis (n = 17), HIV-seropositive patients with tuberculous peritonitis (n = 6) and in patients with cirrhosis (n = 22) and malignancy (n = 5).

RESULTS

ADA(T) and ADA2 isoenzyme activities of HIV-seronegative (ADA(T) = 109 U/l; ADA2 = 94 U/l) and HIV-seropositive (ADA(T) = 109.5 U/l; ADA2 = 95.5 U/l) patients with tuberculous peritonitis, respectively, were significantly different (P < 0.001) from patients with cirrhosis (ADA(T) = 10.5 U/l; ADA2 = 8 U/l) and malignancy (ADA(T) = 13 U/l; ADA2 = 11 U/l). There was no significant difference in ADA(T) and ADA2 activities between HIV-seropositive and seronegative patients with tuberculous peritonitis. There was no significant correlation between ADA, its isoenzymes and IFN-gamma.

CONCLUSIONS

The diagnosis of tuberculous peritonitis can be made by a sensitive, relatively non-invasive procedure in both HIV-seronegative and seropositive patients with minimal risk to the patient and the investigator. The diagnostic value of ADA(T) is not enhanced by measuring ADA isoenzymes or IFN-gamma.

The use of a side effect as a qualitative indicator of plasma chlorpromazine levels

Chlorpromazine (CPZ) is widely used in South African hospitals. The purpose of this study was to determine whether any physiological parameter (side-effect) could be correlated with plasma concentrations of CPZ or its metabolites. In the absence of a blood level, such a correlation could serve as a qualitative indicator of the amount of chlorpromazine in the body. Such a marker can assist the psychiatrist with therapeutic decisions regarding poor compliance and the lack of response with the drug. Fifteen schizophrenic patients were included in this study and regression analysis was used to determine any correlation between CPZ, 7-hydroxychlorpromazine, Chlorpromazine-N-oxide, Nor1 chlorpromazine, Nor2 chlorpromazine, chlorpromazine sulfoxide, Nor2 chlorpromazine sulfoxide and blood pressure, pulse rate, sedation and finger tremor. No correlation was seen between blood pressure or pulse rate and plasma concentrations of CPZ or the metabolites. A good correlation was seen between sedation, 7- hydroxychlorpromazine (P=0.035) and chlorpromazine sulfoxide (P=0.016). The results suggest that as the levels of chlorpromazine sulfoxide increase, the probability of sedation increases, while increasing levels of 7-hydroxychlorpromazine have the opposite effect. A good correlation was also seen between finger tremor and chlorpromazine levels (P=0.035). These results suggest that there is a 50% probability that the patient would experience finger tremor when the plasma concentration of chlorpromazine is 46 ng/ml. This study demonstrated the potential for the use of sedation and finger tremor as qualitative indicators of the plasma concentration of CPZ and two metabolites. Further studies with larger patient numbers are warranted.

Models to predict the intensity of Plasmodium falciparum transmission: applications to the burden of disease in Kenya

There is an increasing need to provide spatial distribution maps of the clinical burden of Plasmodium falciparum malaria in Africa. Recent evidence suggests that risk groups and the clinical spectrum of severe malaria are related to the intensity of P. falciparum transmission. Climate operates to affect the vectorial capacity of P. falciparum transmission and this is particularly important in the Horn of Africa and parts of East Africa. We have used a fuzzy logic climate suitability model to define areas of Kenya unsuitable for stable transmission. Kenya's unstable transmission areas can be divided into areas where transmission potential is limited by low rainfall or low temperature and, combined, encompass over 8 million people. Among areas of stable transmission we have used empirical data on P. falciparum infection rates among 124 childhood populations in Kenya to develop a climate-based statistical model of transmission intensity. This model correctly identified 75% (95% confidence interval CI 70-85) of 3 endemicity classes (low, < 20%; high, > or = 70%; and intermediate parasite prevalences). The model was applied to meteorological and remote sensed data using a geographical information system to provide estimates of endemicity for all of the 1080 populated fourth level administrative regions in Kenya. National census data for 1989 on the childhood populations within each administrative region were projected to provide 1997 estimates. Endemicity-specific estimates of morbidity and mortality were derived from published and unpublished sources and applied to their corresponding exposed-to-risk childhood populations. This combined transmission, population and disease-risk model suggested that every day in Kenya approximately 72 and 400 children below the age of 5 years either die or develop clinical malaria warranting in-patient care, respectively. Despite several limitations, such an approach goes beyond 'best guesses' to provide informed estimates of the geographical burden of malaria and its fatal consequences in Kenya.

The early natural history of vertically transmitted HIV-1 infection in African children from Durban, South Africa

Forty-eight children with vertically transmitted HIV-1 infection and 93 uninfected infants were followed up at regular intervals from birth for a mean of 26 months. They were examined physically, growth and development were assessed and illnesses recorded. Seventy per cent of infected infants were symptomatic by 6 months. Relative risks in the infected infants were highest for lymphadenopathy (4.56; CI 2.7-7.7), failure to thrive (4.48; 2.57-7.81), and neurological abnormalities (3.32; 1.9-5.58). The most frequent findings were diarrhoea (78%), pneumonia (76%) and lymphadenopathy (70%). Thrush and pneumonia occurred early but declined over time, whereas diarrhoea and neurological abnormalities occurred later and increased in frequency. A diagnosis of AIDS was made in 44% of infected infants by 12 months of age. Mortality in infected infants was 35.4%, and 76% of deaths occurred within the 1st year. About two-thirds of HIV-infected infants survived into early childhood. In South African children with vertically acquired HIV-1 infection the onset of disease is early and deterioration to AIDS and death are rapid. Infected infants can be easily recognized clinically, the majority by 6 months of age.

A comparison of mebendazole and albendazole in treating children with Trichuris trichiura infection in Durban, South Africa

OBJECTIVE

To compare the efficacy of mebendazole 500 mg and albendazole 400 mg single-dose treatments of Trichuris trichiura infection in children in the Durban area of KwaZuluNatal, South Africa.

DESIGN

A single-blind randomised trial in children with a documented moderate infection of T. trichiura. Ova were counted in stool specimens before and 10 days after treatment by the formal-ether concentration method.

SETTING

Two shelters for abandoned and orphaned children in Durban.

PARTICIPANTS

Ninety-six children aged between 2 and 12 years.

OUTCOME MEASURES

The number of children who showed reduced T. trichiura ova counts after the treatments, and reductions in ova counts, both expressed as percentages. Statistical analysis using the Wilcoxon 2-sample test and the chi-square test.

RESULTS

Eighty-two children completed the trial; 42 received mebendazole and 40 albendazole. Of the mebendazole group 85% showed a reduction in T. trichiura ova count, compared with 75% of children who received albendazole. Mebendazole treatment was associated with a median percentage reduction in ova count of 72.2%, which significantly exceeded the 44.1% reduction after albendazole (P = 0.024).

CONCLUSION

The mebendazole 500 mg single-dose therapy was more efficacious than the albendazole 400 mg single-dose therapy in treating T. trichiura infection in these children.

Perinatal outcome of babies born to black South African women with hypertension

BACKGROUND

Perinatal mortality rates (PMR) associated with hypertension are known to be high but there have been isolated reports that primigravidae who develop hypertension late in pregnancy have a better PMR than normotensive gravid women.

OBJECTIVE

To verify this report and compare the perinatal outcome in differing categories of hypertensive disorders of pregnancy.

DESIGN

Maternal and neonatal data were recorded for all hypertensive patients admitted to King Edward VIII Hospital over a six month period from January to June 1995. In addition, similar data from normotensive women matched for age, parity and gestational age were also recorded. The latter formed the control group.

RESULTS

Three hundred and thirty seven women were entered into the study. Group A consisted of 189 patients with hypertension, while group B consisted of 148 normotensive pregnant women. There were no significant differences between the groups in relation to maternal age and parity. More women in the hypertensive group had Caesarean sections than in the control group (study group 115 versus control 35: p = 0.001). The perinatal outcome (SBs + NNDs) was significantly greater in the control group than in the hypertensive group (p = 0.031). More importantly, the number of perinatal deaths in the aproteinuric group was significantly different from the control group (aproteinuric group = 2; control group = 26, p = 0.007). Furthermore, the hypertensive group had greater foetal weights than the control groups (controls 1.65 kg versus 2.3 kg hypertensives: p = 0.0001).

CONCLUSION

This study shows that babies born to hypertensive mothers have a significantly greater birthweight than a control group of normotensive women. Further, although there are no statistically significant differences in perinatal outcome between moderate and severe categories of hypertension and control patients, there were significantly fewer perinatal deaths in women with aproteinuric hypertension.

Meconium aspiration syndrome: importance of the monitoring of labor

OBJECTIVE

This study was conducted to identify the associated obstetric and neonatal factors in babies with meconium aspiration syndrome.

STUDY DESIGN

All babies diagnosed with meconium aspiration were included in the study. Maternal details, monitoring of labor, and mode of delivery were recorded. The neonatal details included Apgar scores, resuscitation, weight, gestational age, and the grading of the radiographs for severity of meconium aspiration syndrome. Outcome was determined as survival or death, the need for mechanical ventilation, and the severity of the radiographic changes.

RESULTS

Of the 55 patients entered into the study 8 babies (14.5%) died and 23 (42%) received mechanical ventilation. Fifty-four percent of the babies were born postterm. Univariate analysis revealed that the lack of monitoring of the labor was the most significant variable associated with moderate to severe radiographic changes (p = 0.008). Tracheal suction was significantly associated with more severe radiographic changes (p = 0.008). One (8.2%) of 12 babies with mild radiographic changes had an arterial pH < 7.2 (p = 0.032). Multivariate analysis showed that mortality and the need for mechanical ventilation were associated with monitoring of labor and with prolonged resuscitation. Moderate to severe changes on radiograms were associated with tracheal suction and with prolonged resuscitation. The obstetric complications in this study were those commonly seen in the local obstetric practice.

CONCLUSION

The monitoring of labor was the most significant factor in the reduction of meconium aspiration syndrome. The presence of more severe radiologic changes in those babies who had tracheal suction and a lower arterial pH supports the view that aspiration occurs in some babies before delivery. The number of babies delivered postterm suggests that avoidance of postmaturity is a further preventive factor in meconium aspiration syndrome.

Validation of an outcome prediction model for critically ill trauma patients without head injury

BACKGROUND

The Acute Physiology and Chronic Health Evaluation (APACHE) II system is inaccurate in predicting the risk of death in trauma patients, especially those without head injury. Using multivariate analysis of the APACHE II system in a development set, a new predictive equation was modeled. The four variables that were independently associated with mortality were PaO2/FiO2 ratio, mean arterial pressure, temperature, and the need for inotropic support. This model was tested prospectively in an independent validation set of 300 patients.

METHODS

Risk of death was calculated using the APACHE II system with the diagnostic category of multiple trauma and weighting for operative intervention as required. The new model was similarly assessed using the four predictor variables and their beta-coefficients for each mechanism of injury and the entire group. The predicted risk of death derived by both models was compared with the observed mortality rate. Discrimination was calculated using a 2 x 2 decision matrix with a decision threshold of r = 0.5 and receiver operating characteristic curves. Calibration was assessed graphically and by statistical correlation.

RESULTS

The observed mortality rate was 28.3% and the predicted mortality risk was 27.4% for the model and 6.26% for APACHE II. The sensitivity and specificity of the model were 58.8 and 90.7%, and the sensitivity and specificity of APACHE II were 1.2 and 100%. The areas under the receiver operating characteristic curves were 0.84 and 0.78 for the model and the APACHE II system, respectively. Calibration of the model was superior within all deciles of risk (model, R2 = 0.93, p < 0.001; APACHE II, R2 = 0.82, p = 0.02).

CONCLUSION

The model accurately predicted the risk of death for the entire group. It is superior to the APACHE II system and is the highest reported sensitivity for 24-hour intensive care unit predictive models that have been applied to the critically injured.

Levels of health care at academic and regional hospitals in KwaZulu-Natal

OBJECTIVE

To assess the levels of health care based on hospital bed utilisation at seven academic and regional hospitals in KwaZulu-Natal.

DESIGN

A prospective study. The registrar in charge of patients documented the level of care needed for each patient over 7 consecutive days. Independent assessment by consultants was used to validate the results.

SETTING

All wards in public sector regional and tertiary hospitals with acute general beds in Durban and Pietermaritzburg, except intensive care, coronary care and respiratory units.

PARTICIPANTS

All inpatients present in the wards. The response rate of wards participating in the study varied between hospitals from 32% to 75%. Data on 14,858 patient days were analysed.

OUTCOME MEASURES

Inpatients were classified according to levels of care based on patient days.

RESULTS

The proportion of patients in the tertiary (King Edward) and regional hospitals requiring levels of care below that for which the hospital was designated ranged from 54% to 72% of the patient days. Wentworth Hospital, which is a tertiary referral centre, had 30% of its patient days judged to be below the designated level. Patient days below the designated level of care for that hospital were significantly higher in tertiary than in regional hospitals (P < 0.001).

CONCLUSIONS

All seven hospitals admitted patients at levels of care below that for which the hospital was designated. These findings have important implications for the efficient utilisation and planning of health and hospital services, and for their evaluation and management.

Seroepidemiological study of Helicobacter pylori infection in South African children

The seroepidemiology of Helicobacter pylori infection was studied in 681 randomly selected Black children from newborn to 13 years of age (333 boys, mean age 8.05 years, and 348 girls, mean age 7.76 years) in KwaZulu/Natal, South Africa. H. pylori infection was identified serologically using an enzyme-linked immunosorbent assay to detect the presence of immunoglobulin G against H. pylori. Demographic information collected included age, gender, family income, overcrowding, educational level, and possession of domestic pets. The seroprevalence of H. pylori infection was compared to a known faecal-orally transmitted infection, hepatitis A virus (HAV); 66% of the children were seropositive for H. pylori. There was an age-specific increase in H. pylori infection, with more than 80% of children being infected by the age of 10 years. There was no significant difference (P = 0.338) in the seropositivity of H. pylori infection between boys (68%) and girls (64%), nor was there any significant difference in H. pylori infection related to pets, level of parents' education, crowding, and income, by either univariate or multivariate analysis. However, there was a significant association (P < 0.00001) between the seroprevalence of H. pylori and HAV infections, suggesting similar modes of transmission.

Transient impaired glucose tolerance in South African Indians does not carry a risk for progression to NIDDM

OBJECTIVE

To evaluate the significance of transient impaired glucose tolerance (IGT) in terms of the risk of progression to NIDDM and the serum insulin response during oral glucose tolerance test (OGTT) in a prospective study on the natural history of IGT in South African Indians.

RESEARCH DESIGN AND METHODS

This is a report on 87 subjects who formed part of a 4-year prospective study in 128 subjects classified with IGT at baseline (year 0) using World Health Organization criteria for glucose tolerance. Subjects were reexamined at years 1 and 4. At year 1, based on OGTT results, the subjects were divided into three groups: transient IGT (normal glucose tolerance [trIGT], n = 40), persistent IGT (pIGT, n = 47), and diabetes (n = 41). Analysis was performed on the 87 subjects who were classified as IGT at year 0, but who had not progressed to NIDDM by year 1 of the study At baseline (year 0), a modified OGTT was performed; between years 1 and 4, the OGTT included timed midtest samples for plasma glucose and serum insulin. Analysis of predictive factors for progression to diabetes or reversion to normal glucose tolerance was undertaken using year 0 as baseline.

RESULTS

By year 4, 72 subjects (82.8%) completed the study Of the 32 subjects in the trIGT group, none (0%) had progressed to NIDDM, 11 (34.4%) had reverted to IGT (N-IGT), and 21 (65.6%) had persisted with normal glucose tolerance (N-N); of the 40 subjects in the pIGT group, 16 (40%) had progressed to NIDDM (IGT-D), 17 (42.5%) had persisted with IGT (IGT-IGT), and 7 (17.5%) had reverted to normal glucose tolerance (IGT-N). Significant predictive factors for reversion to normal glucose tolerance included absence of obesity (P = 0.0131, odds ratio [OR] 4.2, 95% CI 1.4-13.1) and 2-h plasma glucose level (P = 0.027, OR 2.4, 95% CI 1.11-5.13) at baseline (year 0). Intergroup (cross-sectional) analysis showed that the serum insulin response was higher in the pIGT than in the trIGT subgroup (fasting serum insulin: IGT-N vs. N-IGT and N-N, 16.9 +/- 1.9 vs. 6.8 +/- 2.1 and 6.1 +/- 2.4 microU/ml, respectively, P < 0.001; 2-h postload serum insulin: IGT-IGT vs. N-IGT, 116.8 +/- 2.2 vs. 60.3 +/- 1.7 microU/ml, P < 0.05). By contrast, the insulinogenic index was higher in the trIGT subgroups both at year 1 (90-min: N-N vs. IGT-D, 48.9 +/- 3.9 vs. 14.1 +/- 2.5; P < 0.05) and at year 4 (N-N vs. remaining four subgroups, P < 0.01 at 60 min and 90 min). Intragroup (prospective) comparisons showed that in the N-IGT subgroup, the mean 2-h insulinogenic index was lower at year 4 than at year 1 (19.9 +/- 1.7 vs. 66.0 +/- 2.7; P < 0.05).

CONCLUSIONS

In this 4-year prospective study in South African Indians, transient IGT carries no risk of progression to NIDDM. The significant predictive factors for reversion to normal glucose tolerance include lower baseline obesity prevalence and 2-h postload plasma glucose level. Moreover, in this group, beta-cell secretory function appeared to deteriorate with worsening of glucose tolerance.

Development of a health programme in a peri-urban informal settlement in Besters, KwaZulu-Natal

OBJECTIVES

The demographic, socio-economic and environmental status of the peri-urban informal settlement of Besters and its inhabitants' health, welfare and disability profiles were investigated for the development of a community-based health intervention programme.

STUDY DESIGN

A cross-sectional study using a structured household questionnaire assessed community health status in July 1991 in order to identify specific health and development needs through focus group discussions and community consultations. A health and development programme was established during 1992. Community participation in this programme was then assessed by measurement of the components of the health and development programme, categorised as inputs (resources), processes (activities), outputs (effects) and outcomes.

SETTING

Besters, an informal peri-urban settlement north of Durban, KwaZulu-Natal.

SUBJECTS

Residents of Besters.

RESULTS

The demographic, environmental and morbidity profiles of Besters were consistent with both South African and international studies of informal communities. Patterns of health service utilisation reflected inappropriate use of the tertiary hospital in the city centre, grossly fragmented patterns of utilisation--both for preventive and curative care and for antenatal and maternity services--and, finally, a discordance between community health needs and ability to pay for services. The interaction between input, process and output measures of community participation are discussed.

CONCLUSION

Integration of health service provision with other infrastructural development, based on community perceptions, enhances health development and community participation. Important lessons emerged about the strengths and limitations of community participation and its relevance for other communities.