Predictive factors for latent tuberculosis infection among adolescents in a high-burden area in South Africa

SETTING

A high tuberculosis (TB) burden area in South Africa (notification rate for all TB cases 1400 per 100 000 population).

OBJECTIVE

To determine the prevalence of and predictive factors associated with latent TB infection in adolescents.

DESIGN

Adolescents aged 12-18 years were recruited from high schools, clinical and demographic data were collected, and a tuberculin skin test (TST) and a QuantiFERON®-TB Gold In-Tube (QFT) assay performed.

RESULTS

A total of 6363 (58.2%) of 10 942 adolescents at the schools were enrolled. After exclusions, of 5244 participants, 55.2% (95%CI 53.8-56.5) had TST ≥ 5 mm, while 50.9% (49.5-52.2) were QFT-positive. On multivariate analysis, Black/mixed race racial groups, male sex, older age, household TB contact, low income and low education level were predictive factors for both TST- and QFT-positive results.

CONCLUSION

About half of the adolescents were found to be latently infected with TB in a high TB burden area with demographic and poverty-related socio-economic factors predicting the risk of TB infection. Adolescents from deprived communities should be considered an important target group for educational interventions by TB control programmes in high-burden settings.

Consensus statement on the revised World Health Organization recommendations for BCG vaccination in HIV-infected infants

This document outlines the consensus agreement from the Union's BCG Working Group regarding BCG vaccination in HIV-infected infants, in response to recently revised World Health Organization (WHO) guidelines, which make HIV infection in infants a full contraindication to bacille Calmette-Guérin (BCG) vaccination. BCG is one of the most widely given vaccines globally and is safe in immunocompetent individuals. Recent evidence shows that HIV-infected infants who were routinely vaccinated with BCG at birth, when asymptomatic, and who later developed AIDS, are at high risk of developing disseminated BCG disease (estimated incidence 407-1300 per 100 000). The document outlines requirements to implement selective BCG vaccination strategies in infants born to HIV-infected women and strategies to reduce the risk of vertical HIV transmission and disseminated BCG disease in infants.

Comparison of mantoux skin test with three generations of a whole blood IFN-gamma assay for tuberculosis infection

SETTING

A rural town in South Africa.

OBJECTIVE

To compare the performance of Quanti-FERON assays with the tuberculin skin test (TST) for identifying latent tuberculosis infection (LTBI) in a high TB burden community.

DESIGN

In a cross-sectional study in healthy adults, we applied the TST and took blood for the three generations of QuantiFERON assays.

RESULTS

Of 358 participants whose results were analysed, 291 (81%) had a TST result of > or = 10 mm induration, and 187 (52%) > or = 15 mm. QuantiFERON-TB was positive in 215 (60%), QuantiFERON-TB Gold in 137 (38%), and QuantiFERON-TB Gold (In-Tube method) in 201 (56%). There was poor agreement between TST and QuantiFERON tests, and between the different generations of QuantiFERON tests (kappa = 0.12-0.50). Of the subset with TST indurations > or = 15 mm, 30-56% had negative QuantiFERON tests. However, positive Quanti-FERON tests were associated with males, who have a higher incidence of TB in this area.

CONCLUSION

We showed poor agreement between TST and the different QuantiFERON tests in diagnosing LTBI. The surprising discordance between the Quanti-FERON TB Gold and QuantiFERON TB Gold (In-Tube method) tests needs to be investigated further.

Outcome of HIV infected children with culture confirmed tuberculosis

BACKGROUND

Tuberculosis (TB) is an important disease in human immunodeficiency virus (HIV) infected children living in regions where TB is endemic. There are limited data on the outcome of culture confirmed TB in HIV infected children.

AIMS AND METHODS

To describe the outcome on TB therapy and overall mortality in HIV infected children with culture confirmed TB through a retrospective cohort study.

RESULTS

Eighty seven children, median age 24 months, contributed to 93 TB episodes; six children had two confirmed episodes. Pulmonary disease (PTB) was present in 71 episodes (76.3%), extrapulmonary disease (EPTB) in 43 (46.2%), and of these, both PTB and EPTB were present in 21 (22.6%). There was cure based on bacteriological and/or radiological criteria in 54 episodes (58.1%). Eighteen children died during TB therapy and there were a total of 34 deaths (39.1%). In univariate analysis (n = 87 patients), severe malnutrition, age < or =1 year, and a negative tuberculin skin test were significant risk factors for death during TB therapy. In multivariate survival analysis (n = 87 patients), HIV disease category, severe malnutrition at diagnosis, and lack of cure at the end of TB therapy were significantly associated with overall mortality.

CONCLUSION

In the absence of antiretroviral therapy, HIV infected children with confirmed TB have poor outcomes on antituberculosis therapy and are at high risk of death during and after completion of antituberculosis therapy, especially due to non-TB related causes. There is an urgent need to optimise and monitor antituberculosis therapy in HIV infected children and to improve access to TB and other preventative therapy.

Plasma vitamin A and zinc levels in HIV-infected adults in Cape Town, South Africa

A cross-sectional study of 132 adults attending an HIV clinic in Cape Town, South Africa, was conducted to determine predictors of low plasma vitamin A and Zn levels. No patients were on antiretroviral therapy. The possible confounding effect of the acute-phase response was controlled by including C-reactive protein levels in multivariate analysis and by excluding active opportunistic infections. Retinol levels were low (<1.05 micromol/l) in 39 % of patients with early disease (WHO clinical stages I and II) compared with 48 and 79 % of patients with WHO stage III and IV respectively (P<0.01). Plasma Zn levels were low (<10.7 micromol/l) in 20 % of patients with early disease v. 36 and 45 % with stage III and IV disease respectively (P<0.05). C-reactive protein levels were normal in 63 % of subjects. Weak, positive associations were found between CD4+ lymphocyte count and plasma levels of retinol (r 0.27; 95 % CI 0.1, 0.43) and Zn (r 0.31; 95 % CI 0.25, 0.46). Multivariate analysis showed the following independent predictors of low retinol levels: WHO stage IV (odds ratio 3.4; 95 % CI 2.1, 5.7) and body weight (odds ratio per 5 kg decrease 1.15; 95 % CI, 1.08, 1.25), while only body weight was significantly associated with low Zn levels (OR per 5 kg decrease 1.19; 95 % CI 1.09, 1.30). CD4+ lymphocyte count <200/microl was not significantly associated with either low retinol or Zn levels. In resource-poor settings, simple clinical features (advanced disease and/or weight loss) are associated with lowered blood concentrations of vitamin A and/or Zn. The clinical significance of low plasma retinol and/or Zn levels is unclear and more research is required to establish the role of multiple micronutrient intervention strategies in HIV disease.

The immunomodulatory effects of thalidomide on human immunodeficiency virus-infected children

The safety and immune effects of low-dose thalidomide treatment (3 mg/kg/day for 28 days) were evaluated in a study involving 8 South African human immunodeficiency virus (HIV)-infected children. The children were 7-69 months old and in disease stages A1-C3. Thalidomide therapy did not affect virus load, even though none of the children was receiving antiretroviral therapy. Thalidomide stimulated CD8+ T cells in peripheral blood, which increased expression of the activation markers CD38 and human leukocyte antigen DR and of the memory cell marker CD45RO. The frequency of HIV gag-specific CD8+ T cells in peripheral blood increased in 3 of 4 children who were evaluated during treatment with thalidomide. Clinical adverse events were mild. In this study, thalidomide was found to be safe and well tolerated and caused significant immunomodulation at a low dose. This is the first report describing use of an oral drug that may enhance HIV-specific CD8+ T cell function in HIV-infected children.

Duration of illness in ambulatory children diagnosed with bronchiolitis

OBJECTIVES

To measure the duration of illness in ambulatory children diagnosed with bronchiolitis and to examine clinical predictors of duration of illness.

DESIGN

Validation inception cohort study. Duration of follow up was 28 days.

SETTING

A primary-level ambulatory department of a public sector children's hospital in Cape Town, South Africa.

PATIENTS

One hundred eighty-one children aged 2 to 23 months who went to the hospital as their first contact for that episode of illness, and had a clinical diagnosis of bronchiolitis were enrolled consecutively on weekday mornings if their guardian stated that they were contactable by telephone.

MAIN OUTCOME MEASURE

Resolution of symptoms, as judged by the guardian, measured by twice-weekly telephone interviews.

RESULTS

Median duration of illness (calculated as the reported duration of symptoms before initial hospital visit plus the time from first consultation to recovery) was 12 days (95% confidence interval, 11-14 days). After 21 days, 18% were still ill and after 28 days, 9% were still ill. Sixty-two patients (34.2%) had unscheduled consultations within 28 days, a median of 13 days after the first consultation. There was no association of duration of illness with age, sex, z score for weight for age, or respiratory rate.

CONCLUSIONS

Ambulatory children diagnosed with bronchiolitis recover with few complications, but the resolution of symptoms may take several weeks. Providing parents with this information could help reduce the high rate of unscheduled return visits as observed in this cohort.

Twice weekly vs. daily chemotherapy for childhood tuberculosis

BACKGROUND

Treating childhood tuberculosis places a large burden on health services, and ways of lessening this were sought.

METHODS

A randomized controlled trial was conducted to determine the effectiveness of fully intermittent twice weekly treatment for intrathoracic childhood tuberculosis and its effect on adherence to treatment, in comparison with daily (weekday) treatment. The setting was a district of Cape Town, South Africa, an area of high incident tuberculosis. We randomized 206 children with confirmed (4%), probable (94%) and suspected (2%) intrathoracic tuberculosis: 89 (median age, 25 months) received intermittent treatment; and 117 (median age, 28 months) received daily treatment. Intermittent treatment (twice weekly for 6 months) was isoniazid 15 mg/kg/dose, rifampin 15 mg/kg/dose and pyrazinamide 55 mg/kg/dose for 2 months, followed by isoniazid and rifampin only for 4 months. Daily treatment was isoniazid 10 mg/kg/day, rifampin 10 mg/kg/day and pyrazinamide 25 mg/kg/day on weekdays for 6 months.

RESULTS

At 6 months 97% of subjects were discharged, with treatment outcomes in the two groups equivalent at that time (P = 0.90) and at the 18- to 30-month follow-up. One relapse occurred in the twice weekly group (P = 0.25). Adherence was equivalent; 70 children (79%) on intermittent and 90 (77%) on daily treatment took 75% or more of the prescribed doses (P = 0.90). Nonadherence over the full course of therapy was significantly associated with nonadherence during the first month of treatment (P = 0.0002) and household crowding (P = 0.002).

CONCLUSIONS

Six month fully intermittent antituberculosis treatment is an effective and acceptable alternative to daily treatment.

Respiratory syncytial virus infection in children hospitalised with acute lower respiratory tract infection

BACKGROUND

Data are lacking on respiratory syncytial virus. (RSV) respiratory tract infections in children from developing countries.

OBJECTIVE

To determine the importance of RSV as a cause of acute lower respiratory tract infection (ALRTI) in Cape Town children.

METHODS

Children younger than 2 years of age admitted to hospital with ALRTI over a 15-month period from 1 June 1995 to 31 August 1996 were studied prospectively. Sociodemographic data, risk factors for severe RSV disease, clinical signs, diagnosis and hospital course were documented. A nasopharyngeal aspirate (NPA) for detection of RSV by enzyme immunoassay (EIA) was obtained in all cases. The NPA of every fifth child was sent for viral culture.

RESULTS

A total of 1,288 patients (60% male, 40% female) with a median age (25th-75th percentile) of 6 months (2-11 months) was enrolled; 32.4 had one or more risk factors for severe RSV infection. Pneumonia was diagnosed in 62.2%, bronchiolitis in 20.6%, laryngotracheobronchitis (LTB) in 8% and other respiratory illnesses in 9.2%. Mild disease, requiring admission to an overnight ward, was documented in 38.1%, while 48.9% and 13% respectively had moderate and severe disease requiring admission to a general ward and intensive care unit (ICU). Supplemental oxygen and mechanical ventilation were required by 68.9% and 8.5% of patients, respectively. The median duration of hospital stay was 5 days (range 1-10 days). RSV EIA was positive in 16.4% of cases, and there was no difference in detection rates according to diagnosis. Viral culture performed in 162 of the 1,288 study patients (12.6%) grew RSV in 11.7% of cases, adenovirus in 3.7%, para-influenza virus type 3 in 2.5% and influenza B virus in 0.6%. Patients who tested RSV EIA-positive did not significantly differ from those who tested negative with regard to demographic variables, clinical diagnoses, risk factors for RSV or length of hospitalisation. The only significant difference noted was the presence of hyperinflation, which occurred in 70.1% of EIA-positive patients compared with 57.1% of those testing negative (P = 0.0005). The mortality rate (2%) was similar for both groups.

CONCLUSION

This study indicates that RSV is an important cause of hospitalisation in infants and young children with ALRTI. Distinguishing RSV from other ALRTIs is difficult because of similarity in clinical presentation among children.

Effect of vitamin A therapy on serologic responses and viral load changes after influenza vaccination in children infected with the human immunodeficiency virus

Vitamin A administered to children infected with the human immunodeficiency virus before influenza vaccination in a double-blind randomized study did not enhance vaccine serologic responses but did dampen the increase in the human immunodeficiency virus viral load 14 days after immunization (vitamin A, decrease of 0.13 +/- 0.09 log(10) copies/mL; placebo, increase of 0.14 +/- 0.08, P =.02).

Immunological manifestations of HIV-infected children

This cross-sectional study of stable HIV-infected children was designed to document the immunological manifestations of paediatric HIV infection and to determine whether inexpensive markers of immunosuppression could be identified. Investigations included lymphocyte count and subset analysis, levels of total protein, albumin, immunoglobulins, beta-2 microglobulin and neopterin. The median age of the 74 children studied was 16.5 months and 76% and 39% had subnormal percentage CD4+ counts and absolute CD4+ counts, respectively. According to the Centers for Disease Control (CDC) guidelines, 85% were moderately or severely immunosuppressed. The majority had elevated neopterin, beta-2 microglobulin, IgG, IgM and IgA concentrations. The IgG concentration correlated positively with total globulin, IgG1 and IgG3 concentrations. On bivariate analysis, the absolute CD4+ count correlated positively with total lymphocyte count (r = 0.28 < 0.48 < 0.64) and negatively with total IgG concentration (r = -0.47 < -0.27 < -0.04), IgG1 concentration (r = -0.51 < -0.31 < -0.08), and neopterin concentration (r = -0.49 < -0.28 < -0.04). There was no correlation between CD4+ count, total globulin or beta-2 microglobulin concentration. On multiple linear regression analysis only the total lymphocyte count correlated with CD4+ count. Furthermore, on bivariate analysis total lymphocyte count correlated positively with absolute CD8+ count (r = 0.82 < 0.88 < 0.92). In conclusion, although there was a positive correlation between absolute CD4+ count and total lymphocyte count, the clinical significance is questionable as the total lymphocyte count correlated more strongly with the absolute CD8+ count.

Plasma-soluble CD30 in childhood tuberculosis: effects of disease severity, nutritional status, and vitamin A therapy

Plasma-soluble CD30 (sCD30) is the result of proteolytic splicing from the membrane-bound form of CD30, a putative marker of type 2 cytokine-producing cells. We measured sCD30 levels in children with tuberculosis, a disease characterized by prominent type 1 lymphocyte cytokine responses. We postulated that disease severity and nutritional status would alter cytokine responses and therefore sCD30 levels. Samples from South African children enrolled prospectively at the time of diagnosis of tuberculosis were analyzed. (Patients were originally enrolled in a randomized, double-blind placebo-controlled study of the effects of oral vitamin A supplementation on prognosis of tuberculosis.) Plasma samples collected at the time of diagnosis and 6 and 12 weeks later (during antituberculosis therapy) were analyzed. sCD30 levels were measured by enzyme immunoassay. The 91 children included in the study demonstrated high levels of sCD30 at diagnosis (median, 98 U/liter; range, 11 to 1,569 U/liter). Although there was a trend toward higher sCD30 levels in more severe disease (e.g., culture-positive disease or miliary disease), this was not statistically significant. Significantly higher sCD30 levels were demonstrated in the presence of nutritional compromise: the sCD30 level was higher in patients with a weight below the third percentile for age, in those with clinical signs of kwashiorkor, and in those with a low hemoglobin content. There was minimal change in the sCD30 level after 12 weeks of therapy, even though patients improved clinically. However, changes in sCD30 after 12 weeks differed significantly when 46 patients (51%) who received vitamin A were compared with those who had received a placebo. Vitamin A-supplemented children demonstrated a mean (+/- standard error of the mean) decrease in sCD30 by a factor of 0.99 +/- 0.02 over 12 weeks, whereas a factor increase of 1.05 +/- 0.02 was demonstrated in the placebo group (P = 0.02). We conclude that children with tuberculosis had high sCD30 levels, which may reflect the presence of a type 2 cytokine response. Nutritional compromise was associated with higher sCD30 levels. Vitamin A therapy resulted in modulation of sCD30 levels over time.

Survival of children in Cape Town known to be vertically infected with HIV-1

OBJECTIVE

To determine the survival patterns of children in Cape Town known to be vertically infected with HIV.

DESIGN

Retrospective record review of children diagnosed with symptomatic HIV infection during the period 1 December 1990-31 May 1995.

SETTING

Hospitals in the Cape Town metropolitan area.

PATIENTS

193 children were known to be vertically HIV-infected. HIV diagnosis was based on the following criteria: two positive HIV enzyme-linked immunosorbent assays (ELISAs) in children older than 15 months and a positive ELISA together with a positive polymerase chain reaction (PCR) in younger children. The mothers of the children were known to be HIV-positive. On the basis of the presenting clinical findings children were assigned to a disease severity category (A, B or C) according to the Centers for Disease Control and Prevention (CDC)'s 1994 revised classification system for HIV infection in children.

OUTCOME MEASURES

Survival was analysed according to the Kaplan-Meier method. Survival time was defined as the length of time between clinical diagnosis of HIV and death or last contact with the health services. Mortality risk in relation to specific variables at diagnosis such as age and clinical manifestations was determined by calculation of odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

The median age at diagnosis was 5 months; 72% of children were aged less than 1 year at diagnosis. According to the CDC clinical classification, 47 (24%) fell into category A, 111 (58%) into category B and 35 (18%) into category C. Of the 193 patients 85 (44%) were alive at the time of review, 65 (34%) had died and 43 (22%) were lost to follow-up. Risk of death was significantly associated with age less than 6 months (OR 4.7, CI 2.1-10.3) and severe disease, i.e. CDC category C (OR 2.7; CI 1.1-6.9) at time of diagnosis. The median survival for all the children from time of diagnosis was 32 months. Infants diagnosed before 6 months of age had significantly shorter median survival (10 months) compared with 36 months for those diagnosed at 7-12 months of age. For the children over the age of 12 months the cumulative proportion surviving at 48 months was 78%. Children with severe disease (category C) had a median survival of 21 months, significantly lower than that in category B (32 months). For the children in category A the cumulative proportion surviving at 48 months was 66%.

CONCLUSION

The median survival of children with HIV was 32 months from time of diagnosis, and survival was influenced by age and disease severity.

Randomised controlled trial of clinical outcome after chest radiograph in ambulatory acute lower-respiratory infection in children

BACKGROUND

When available, chest radiographs are used widely in acute lower-respiratory-tract infections in children. Their impact on clinical outcome is unknown.

METHODS

522 children aged 2 to 59 months who met the WHO case definition for pneumonia were randomly allocated to have a chest radiograph or not. The main outcome was time to recovery, measured in a subset of 295 patients contactable by telephone. Subsidiary outcomes included diagnosis, management, and subsequent use of health facilities.

FINDINGS

There was a marginal improvement in time to recovery which was not clinically significant. The median time to recovery was 7 days in both groups (95% CI 6-8 days and 6-9 days in the radiograph and control groups respectively, p=0.50, log-rank test) and the hazard ratio for recovery was 1.08 (95% CI 0.85-1.34). This lack of effect was not modified by clinicians' experience and no subgroups were identified in which the chest radiograph had an effect. Pneumonia and upper-respiratory infections were diagnosed more often and bronchiolitis less often in the radiograph group. Antibiotic use was higher in the radiograph group (60.8% vs 52.2%, p=0.05). There was no difference in subsequent use of health facilities.

INTERPRETATION

Chest radiograph did not affect clinical outcome in outpatient children with acute lower-respiratory infection. This lack of effect is independent of clinicians' experience. There are no clinically identifiable subgroups of children within the WHO case definition of pneumonia who are likely to benefit from a chest radiograph. We conclude that routine use of chest radiography is not beneficial in ambulatory children aged over 2 months with acute lower-respiratory-tract infection.

Vitamin A status and therapy in childhood pulmonary tuberculosis

Low plasma vitamin A levels (mean, 18.1 +/- 10.3 micrograms/dl, 62% below normal) were demonstrated in South African children with pulmonary tuberculosis. More extensive or severe disease (e.g., additional extrapulmonary tuberculosis) and low levels of retinol binding protein, prealbumin, and albumin were associated with low vitamin A levels. High-dose vitamin A therapy had no effect on disease outcome.

Clinical problems in measles case management

Measles remains one of the leading causes of childhood morbidity and mortality in developing countries. The World Health Organization has identified effective case management as one of the specific strategies to reduce the burden of this disease. The purpose of this article is to review the aetiology, natural history, treatment and outcome of the common clinical problems associated with measles with a view to identifying possible deficiencies in case management. Complications such as pneumonia, diarrhoea, croup and malnutrition have been well defined in terms of their relative contribution to morbidity and mortality. However, there are few published data on the aetiology and natural history of these specific complications. Such data are crucial for rational case management strategies. Data on treatment of measles and its complications are limited and the role of antibiotic prophylaxis and therapy is unclear. The only specific research focus on case management during the last decade has been vitamin A therapy. There is a continuing need for community and hospital-based studies on the natural history of measles and its complications, the aetiology of these complications and intervention strategies that will improve measles case management.

The effect of Edmonston-Zagreb and Schwarz measles vaccines on immune response in infants

The effects of measles immunization on immune responses in infants and the roles of vaccine strain and age of immunization are not known. Eighty-eight children were immunized at 6 or 9 months of age with the Edmonston-Zagreb (EZ) or Schwarz (SW6, SW9) strain of measles vaccine. Children were studied before and 2 weeks and 3 months after immunization. Seroconversion was similar, but geometric mean neutralizing titers at 3 months differed by vaccine group: SW9, 1367 mIU/mL; SW6, 982; and EZ, 303 (P = .003). Mitogen-induced lymphoproliferation was decreased at 2 weeks in the SW9 group and at 3 months in all groups and was negatively correlated with measles antibody level at 3 months (r = -.387, P = .003). CD8 T cells, soluble CD8, neopterin, and beta2-microglobulin were increased at 2 weeks in the SW9 group, and soluble CD8 and beta2-microglobulin remained elevated at 3 months. Therefore, measles immunization resulted in suppression of lymphoproliferation, which was most evident in infants with the highest antibody responses and most immune activation.

Changes within T cell receptor V beta subsets in infants following measles vaccination

Measles produces immune suppression which contributes to an increased susceptibility to other infections. Recently, high titered measles vaccines have been linked to increased long-term mortality among some female recipients. Because the mechanisms by which wild-type or attenuated live-vaccine strains of measles virus alter subsequent immune responses are not fully understood, this prompted an examination of the changes within the peripheral blood T cell receptor V beta repertoire following measles immunization. Twenty-four 6- and 9-month-old infants were studied at 2 weeks and 3 months following immunization by semiquantitative reverse transcription-polymerase chain reaction. There was a significant increase in V beta 2 expression (P less than 0.05), and a decrease in the V beta 4 subset (P less than 0.03) 2 weeks following vaccination with subsequent return to baselines at 3 months in vaccine recipients who seroconverted. These data suggest that measles virus may affect immune responses in part by altering the T cell receptor repertoire.

The costs and benefits of a vaccination programme for Haemophilus influenzae type B disease

Haemophilus influenzae type b (Hib) infection is a major cause of severe bacterial infection in young children in South Africa and world-wide. These diseases can be prevented by immunisation with conjugate Hib vaccines. In South Africa, unlike some developed countries, Hib vaccines are not part of the routine immunisation schedule. The objective of this study was to measure the expected net benefits from a hypothetical programme of vaccination of the 1992 Cape Town birth cohort (N = 46,537). Costs were calculated by summing the estimated direct medical care costs together with the indirect costs of Hib disease. The latter were calculated by valuing human life using alternative, and conservative human capital and willingness-to-pay measures. The difference between Hib disease costs (i.e. the benefits which would be gained from a successful vaccination programme) and the costs of the vaccination programme itself (HibTITER, Praxis Biologicals) defined the expected net benefits. In the absence of an immunisation programme, the estimated economic costs of Hib disease in the 1992 Cape Town cohort ranged from R10.7 million to R11.8 million. The costs of introducing the vaccine would have amounted to R8.3 million. Had the vaccine been administered to the 1992 birth cohort, benefits would have exceeded costs by between R2.4 million and R3.5 million.

The 1992 measles epidemic in Cape Town--a changing epidemiological pattern

Over the last 6 years there has been a decline in the incidence of measles in Cape Town. However, during August 1992 an outbreak occurred, with cases reported at many schools in children presumably immunised. The objectives of this study were to characterise the epidemic in Cape Town and to determine possible reasons for the outbreak. The investigation consisted of two components--a description of the epidemic and an investigation of an outbreak at one primary school. Results indicate that during the last 4 months of the year, 757 cases were notified in Cape Town, compared with 144 in the first 8 months. The epidemic affected mainly white and coloured children over 5 years of age (P < 0.001). In contrast, during the period before the epidemic most cases occurred in black children and in those aged less than 1 year (P < 0.001). There was no significant increase in hospitalised cases. Investigation of the outbreak at one school revealed that the attack rate was 7.6% (25/329 children). Immunisation coverage (at least one dose of any measles vaccine) was 91% and vaccine efficacy was estimated to be 79% (95% CI 55-90); it was highest for monovalent measles (100%) and lowest for measles-mumps-rubella (74%). The epidemiology of measles in Cape Town has thus changed as evinced in this epidemic, with an increase in the number of cases occurring in older, previously vaccinated children. The possible reasons for this include both primary and secondary vaccine failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Carriage of Haemophilus influenzae in Cape Town children

Little is known about the epidemiology of Haemophilus influenzae infections in South Africa. This study was designed to determine the prevalence, serotype distribution, antimicrobial susceptibility pattern and effect of age and hospitalisation on the carriage of H. influenzae in 322 Cape Town children. The overall and type b specific carriage rates in normal children (N = 107) were 45.8% and 4.7% respectively. The yield following nasopharyngeal culture was twice that following throat culture (P < 0.001). Children hospitalised with tuberculosis (N = 62) had significantly greater carriage rates, 66.1% and 37.1% respectively (P = 0.02). Institutionalised mentally handicapped children (N = 77) and children with tuberculosis attending an outpatient clinic (N = 76) had lower carriage rates (P < 0.02). Antimicrobial resistance was a major problem only in children hospitalised with tuberculosis (rifampicin 100%, penicillin 43.9%, erythromycin 85.4%, co-trimoxazole 82.9%). This universal resistance to rifampicin has not been reported previously. There was no difference in the mean age of children with positive or negative cultures, with the exception of those hospitalised with tuberculosis. In this group children infected with type b were much younger (mean 19.7 months) than those with other and non-typeable infections (32.1 months) and the non-infected (50.1 months) (P = 0.04). Duration of hospitalisation or outpatient therapy in the patients with tuberculosis did not influence carriage rates.(ABSTRACT TRUNCATED AT 250 WORDS)

Routine high-dose vitamin A therapy for children hospitalized with measles

Measles is without specific therapy and remains important globally as a cause of childhood death. In controlled studies, high-dose vitamin A therapy (Hi-VAT)--with 400,000 IU vitamin A--has been demonstrated to markedly reduce measles-associated morbidity and mortality. We performed a retrospective study of the hospital records of 1720 children < 15 years of age who were hospitalized for measles, to determine the extent to which these findings, in research settings, are applicable to the case management of measles under conditions of routine hospital practice. The outcomes were studied of children hospitalized during two non-consecutive 2 year periods (1985-6 and 1989-90). A policy of Hi-VAT for all children hospitalized with measles was started during the intervening period. As compared with the group of children on standard therapy (n = 1061), children receiving Hi-VAT (n = 651) had a shorter hospital stay (mean 10 versus 13 days; P < 0.001), a lower requirement for intensive care (4.3 versus 10.5 per cent; P < 0.001), and a lower death rate (1.6 versus 5 per cent; P < 0.001). No adverse effects of Hi-VAT therapy were observed. We conclude that a policy of high dose oral vitamin A (400,000 IU) supplementation in measles provides benefits which are equivalent to those previously observed only in controlled research trials, that it is highly cost effective, and that it should form part of the routine case management of all children hospitalized with measles.

A randomized, controlled trial of vitamin A in children with severe measles

BACKGROUND

Measles kills about 2 million children annually, and there is no specific therapy for the disease. It has been suggested that vitamin A may be of benefit in the treatment of measles.

METHODS

We conducted a randomized, double-blind trial involving 189 children who were hospitalized at a regional center in South Africa because of measles complicated by pneumonia, diarrhea, or croup. The children (median age, 10 months) were assigned to receive either vitamin A (total dose, 400,000 IU of retinyl palmitate, given orally; n = 92) or placebo (n = 97), beginning within five days of the onset of the rash. At base line, the characteristics of the two groups were similar.

RESULTS

Although clinically apparent vitamin A deficiency is rare in this population, the children's serum retinol levels were markedly depressed (mean [+/- SEM], 0.405 +/- 0.021 mumols per liter [11.6 +/- 0.6 micrograms per deciliter]), and 92 percent of them had hyporetinemia (serum retinol level less than 0.7 mumols per liter [20 micrograms per deciliter]). Serum concentrations of retinol-binding protein (mean, 30.1 +/- 2.0 mg per liter) and albumin (mean, 33.4 +/- 0.5 g per liter) were also low. As compared with the placebo group, the children who received vitamin A recovered more rapidly from pneumonia (mean, 6.3 vs. 12.4 days, respectively; P less than 0.001) and diarrhea (mean, 5.6 vs. 8.5 days; P less than 0.001), had less croup (13 vs. 27 cases; P = 0.03), and spent fewer days in the hospital (mean, 10.6 vs. 14.8 days; P = 0.01). Of the 12 children who died, 10 were among those given placebo (P = 0.05). For the group treated with vitamin A, the risk of death or a major complication during the hospital stay was half that of the control group (relative risk, 0.51; 95 percent confidence interval, 0.35 to 0.74).

CONCLUSIONS

Treatment with vitamin A reduces morbidity and mortality in measles, and all children with severe measles should be given vitamin A supplements, whether or not they are thought to have a nutritional deficiency.