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F T Cutts

Publications and source records attributed to F T Cutts.

At least 19 recordsLinked to original sources
PubMed1998

Age- and sex-specific HIV-1 prevalence in the urban community setting of Addis Ababa, Ethiopia.

OBJECTIVE: To estimate the age and sex-specific prevalence of HIV infection in the population of Addis Ababa, Ethiopia. DESIGN: Two-stage cluster sampling of the population aged 0-49 years of Addis Ababa, using kebeles (urban dwelling associations) as clusters. METHODS: The sera used for this study were collected in an earlier study (1994) on the rate of acquisition of antibodies against measles, rubella, and hepatitis B. After separate approvals were obtained from the institutional ethics committees, sera were tested by enzyme-linked immunosorbent assay confirmed by Western blot. Age- and sex-specific HIV prevalence rates were estimated. The prevalence of HIV in men and women over 15 years of age was compared by calculating age-standardized HIV prevalence, using the age distribution of the census population as the standard. A time-dependent catalytic model was used to obtain crude estimates of HIV incidence from age-prevalence data. RESULTS: A total of 3853 sera were available for analysis. The prevalence of HIV in adults was 6.0% [95% confidence interval (CI), 4.5-7.4%] for men and 6.9% (95% CI, 5.3-8.5%) for women, with peak prevalence in the 25-29 year age group of 16.3 and 11.8%, respectively. After standardization for age using the direct method, the HIV prevalence ratio comparing adult men with women was 0.97:1 (95% CI, 0.70:1 - 1.35:1). Three children aged less than 5 years were HIV-positive. The prevalence of HIV among adults ranged from 0-21.3% in different clusters, indicating the heterogeneity of the spread of HIV in the city. HIV prevalence estimates among the antenatal clinic patients of Addis Ababa in 1996 far exceeded the estimates obtained during the community survey, particularly in the youngest age group (15-24 years). Estimates of HIV incidence (per susceptible person per annum) for the age group 16-22 years ranged from 1.3-2.25% for men and from 2.1-2.4% for women. CONCLUSION: By 1994, a substantial proportion of the adult population of Addis Ababa was infected with HIV. Promotion of behavioural changes and the control of sexually transmitted diseases should be strongly supported to limit the spread of the HIV epidemic in Ethiopia.

Adolescent↗
PubMed1997

Alternative routes of measles immunization: a review.

Measles is one of the major causes of childhood mortality in developing countries, despite current prevention of over 2 million child deaths each year by measles vaccination programmes. New strategies, such as mass campaigns, and possibly new preparations of measles vaccines, may facilitate further progress in controlling the disease and improving the prospects for its ultimate eradication. To evaluate the potential for non-percutaneous routes of vaccine administration to improve control, we reviewed studies of serological responses to measles vaccine after intradermal, conjunctival, oral, aerosol and intranasal administration. The response to intradermal vaccination exceeded percutaneous results in only one of eight instances in five studies where such comparisons could be made, often producing substantially lower seroresponses. Further, intradermal administration using a needle and syringe is more difficult than subcutaneous vaccination. After oral administration of vaccine, less than 50% of children seroconverted in three small studies. Intranasal administration has not yet been studied extensively, but it may be susceptible to interference by upper respiratory infections. Seroconversion after conjunctival administration was very variable, and this route was difficult practically in young children. In infants below 9 months of age, aerosol administration of vaccine resulted in 80% or better seroresponse in seven of nine trials, with the Edmonston-Zagreb strain in standard titre doses consistently producing better results than the Schwarz strain. However, seroresponses after subcutaneous administration clearly exceeded those from aerosols of the same vaccine in four of six comparisons. Several trials noted practical difficulties in aerosol administration in young infants. In contrast, older seronegative children generally responded well to aerosol administration of vaccine (above 90% and often 100% seroresponse), regardless of vaccine strain and often with surprisingly low estimated retained doses. In each of three studies where it was possible to compare the same vaccines given percutaneously and by aerosol to seropositive children, better seroresponses followed aerosols. In older children, aerosols of the Edmonston-Zagreb strain also rather consistently provided better seroresponses than aerosols of the Schwarz strain, with the most notable differences in seropositive children. Thus, with the possible exception of very young infants, the aerosol route is promising and offers several theoretical and practical advantages as well. Further randomized trials should be conducted to evaluate comparative responses to aerosolized, intranasal, and subcutaneous vaccine, especially in those age ranges targeted for mass campaigns (most commonly 9 months to 15 years). The development of improved technology for aerosol delivery of measles vaccine would greatly advance the potential for wide scale use of this route, especially in mass campaigns in low income countries.

Adolescent↗
PubMed1997

Control of rubella and congenital rubella syndrome (CRS) in developing countries, Part 1: Burden of disease from CRS.

Congenital rubella syndrome (CRS) can lead to deafness, heart disease, and cataracts, and a variety of other permanent manifestations. In developing countries, the burden of CRS has been assessed as follows: by surveillance of CRS; by surveillance of acquired rubella; by age-stratified serosurveys; and by serosurveys documenting the rubella susceptibility of women of childbearing age. During rubella outbreaks, rates of CRS per 1000 live births were at least 1.7 in Israel, 1.7 in Jamaica, 0.7 in Oman, 2.2 in Panama, 1.5 in Singapore, 0.9 in Sri Lanka, and 0.6 in Trinidad and Tobago. These rates are similar to those reported from industrialized countries during the pre-vaccine era. Special studies of CRS have been reported from all WHO regions. Rubella surveillance data show that epidemics occur every 4-7 years, similar to the situation in Europe during the pre-vaccination era. In developing countries, the estimated average age at infection varies from 2-3 years to 8 years. For 45 developing countries we identified serosurveys of women of childbearing age that had enrolled > or = 100 individuals. The proportion of women who remained susceptible to rubella (e.g. seronegative) was < 10% in 13 countries. 10-24% in 20 countries, and > or = 25% in 12 countries. Discussed are methods to improve the surveillance of rubella and CRS in developing countries.

Adolescent↗
PubMed1997

Control of rubella and congenital rubella syndrome (CRS) in developing countries, Part 2: Vaccination against rubella.

In 1995-96 we conducted a review of rubella immunization strategies. Worldwide, 78 countries (more than one-third) reported a national policy of using rubella vaccine. This was closely related to country economic status. Based on the United Nations country classification, rubella vaccine is used in 92% of industrialized countries, 36% of those with economies-in-transition, and 28% of developing countries. Cases of congenital rubella syndrome (CRS) may be prevented as follows: by providing direct protection to women and/or schoolgirls (a selective vaccination strategy); by vaccinating boys and girls to provide indirect protection by reducing the transmission of rubella virus (a childhood vaccination strategy); or by a combination of these approaches (a combined strategy). A combined strategy was most commonly reported (60% of countries); seven countries (9%) reported a selective strategy; and 24 countries (31%) reported only childhood immunization. Experience has shown that it is essential to include vaccination of women of childbearing age in any rubella control strategy. Childhood vaccination alone may pose a risk of an increase in CRS cases. Although many countries have introduced rubella vaccine, few report any data on the impact of vaccination. Countries using rubella vaccine need to establish surveillance for rubella and CRS and monitor coverage in each of the target groups.

Adolescent↗
PubMed1996

Child and maternal mortality during a period of conflict in Beira City, Mozambique.

BACKGROUND: Child mortality rates have been declining in most developing countries. We studied child and maternal mortality risk factors for child mortality in Beira city in July 1993, after a decade of conflict in Mozambique. METHODS: A community-based cluster sample survey of 4609 women of childbearing age was conducted. Indirect techniques were used to estimate child mortality ('children ever born' method and Preceding Birth Techniques (PBT) and maternal mortality (sisterhood method). Deaths among the most recent born child, born since July 1990, were classified as cases (n = 106), and two controls, matched by age and cluster, were selected per case. RESULTS: Indirect estimates of the probability of dying from birth to age 5 (deaths before age 5 years, (5)q(0) per 1000) decreased from 246 in 1977/8 to 212 in 1988/9. The PBT estimate of 1990/91 was 154 (95 percent confidence interval [CI]: 124-184), but recent deaths may have been underreported. Lack of beds in the household (odds ratio [OR] = 2.0, 95 percent CI: 1.1-3.8), absence of the father (OR = 2.4, 95 percent CI : 1.2-4.8), low paternal educational level (OR = 2.1, 95 percent CI: 0.8-5.4), young maternal age (OR = 2.0, 95 percent CI: 1.0-3.7), self-reported maternal illness (OR = 2.4, 95 percent CI : 1.2-4.9), and home delivery of the child (OR = 2.3, 95 percent CI : 1.2-4.5) were associated with increased mortality, but the sensitivity of risk factors was low. Estimated maternal mortality was 410/100 000 live births with a reference date of 1982. CONCLUSIONS: Child mortality decreased slowly over the 1980s in Beira despite poor living conditions caused by the indirect effects of the war. Coverage of health services increased over this period. The appropriateness of a risk approach to maternal-child-health care needs further evaluation.

Adult↗
PubMed1995

The epidemiology of measles: thirty years of vaccination.

Measles is a highly infectious disease which has a major impact on child survival, particularly in developing countries. The importance of understanding the epidemiology of this disease is underlined by its ability to change rapidly in the face of increasing immunization coverage. Much is still to be learned about measles epidemiology and the best strategies for administering measles vaccines, as well as about the biological mechanisms of action of measles vaccines. However, it is clear that tremendous progress can be made in preventing death and disease from measles with existing knowledge about the disease, and by using the presently available vaccines and applying well tried methods of treating cases. Research in the coming decade may provide improved strategies and more effective vaccines for use in immunization programmes.

Animals↗
PubMed1995

The effect of dose and strain of live attenuated measles vaccines on serological responses in young infants.

High morbidity and mortality from measles among infants under 9 months of age is an obstacle to measles control in many developing countries. In this paper, we review 30 studies conducted on the serological response to measles vaccine in infants aged less than 9 months. Among children aged under 9 months, Edmonston Zagreb and AIK-C vaccines produce higher seroresponse rates than Schwarz vaccine of equivalent titre. For Edmonston Zagreb and Schwarz vaccine, seroresponse rates increase with increasing vaccine titre. The absolute rate of seroresponse to Edmonston Zagreb vaccine in 6-month old infants varied greatly between studies because of differences in methods of vaccine titer measurement, serological assays, definitions of seroresponse, and maternal antibody profiles of the populations studied. Seroconversion rates to Edmonston Zagreb or AIK-C vaccines at 6 months of age were generally similar to those to Schwarz vaccine at 9 months of age, but antibody levels were lower after vaccination below 9 months of age. Although the increased mortality documented in other studies after use of high titer vaccines in 4-6 month old infants led to withdrawal of these vaccines, this review of vaccine trials highlights the need for standardization of study methods and for a better understanding of the biological action of measles vaccines.

Dose-Response Relationship, Immunologic↗
PubMed1995

Priorities in global measles control: report of an outbreak in N'Djamena, Chad.

In N'Djamena, capital of Chad, measles vaccination coverage of 12-23-month-old children fell from 61% in 1990 to 15% in 1993. A community survey of measles after an outbreak in 1993 showed that among children < 5 years of age, the mean monthly attack rate was 37 per 1,000 (95% CI, 32-43) and the mean case fatality rate was 7.4%. Measles incidence was highest (77/1,000/month) in children aged 9-11 months and fell among children > 3 years of age. Incidence rates were high (56/1,000/month) among 6-8-month-old children, but only 3 deaths occurred in this age group. Measles vaccine efficacy, estimated by comparing attack rates in unvaccinated and vaccinated children, was 71% (95% CI, 59-80%). Extrapolation of the results to the city population indicated that an estimated 19,000 cases and > 1,000 measles-associated deaths occurred in 1993. This preventable morbidity and mortality, in a city where coverage was formerly among the highest in Africa, shows the need for sustained global commitment to preventive health care.

Age Distribution↗
PubMed1995

Measles vaccination policy.

Where immunization campaigns locally eliminate measles, it will be important to identify the vaccination policy most likely to prevent future epidemics. The optimum age for vaccination depends on the rate of decline of maternal antibody, because the presence of antibody reduces vaccine efficacy. The first part of this paper contains a quantitative reappraisal of the data on antibody decline and seroconversion rates by age. The decline in maternal antibody protection follows delayed exponentials, with delays of 2-4 months, and subsequent half-lives of 1-2 months. Using this result in an analytical mathematical model we find that the optimal age to administer a single dose of vaccine to children, which is independent of vaccine coverage, lies within the range 11-19 months. We also show that, where the optimal age cannot be met, it is better to err towards late rather than early vaccination. There are therefore two reasons why developing countries, which presently vaccinate during infancy because measles transmission rates are high should eventually switch to the second year of life. The possible gains from two-dose vaccination schedules are explored with respect to both coverage and efficacy. A two-dose schedule will be beneficial, in principle, only when there is a need to increase net vaccine efficacy, after coverage has been maximized with a one-dose schedule.

Antibodies, Viral↗
PubMed1994

Immunogenicity of high-titre AIK-C or Edmonston-Zagreb vaccines in 3.5-month-old infants, and of medium- or high-titre Edmonston-Zagreb vaccine in 6-month-old infants, in Kinshasa, Zaire.

The effect of measles vaccine potency was evaluated among 485 children aged 6 months, and the effect of vaccine strain was evaluated among 538 children aged 3.5 months, in Kinshasa, Zaire. Children aged 6 months were randomly assigned to receive either high-titre Edmonston-Zagreb (EZ-H), potency 5.7 log10/dose, or medium-titre EZ (EZ-M), potency 4.7 log10/dose, those aged 3.5 months were randomly assigned to receive either AIK-C, potency 5.5 log10/dose, or EZ-H, and were revaccinated with EZ-M vaccine at age 9.5 months. Measles antibodies were measured using the plaque reduction neutralization assay. Among children vaccinated at age 6 months, the seroresponse was significantly higher after EZ-H than EZ-M vaccine, with 92 and 83% seroconverting by 6 months postvaccination and 59 and 40% respectively having antibody titres > 200 mIU. Among children vaccinated at age 3.5 months, only 24% (AIK-C) and 22% (EZ-H) attained antibody titres > or = 200 mIU 6 months postvaccination. After revaccination at age 9.5 months, 81% of children in the AIK-C group and 73% in the EZ-H group had antibody levels > 200 mIU (p = 0.056). A retrospective survey was conducted in January 1993 to determine the mortality experience of vaccine groups, and information was obtained for 94% of the children. A total of 44 deaths (4%) were identified, with no significant differences between groups when stratified by age at vaccination.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1994

Measles control in Kinshasa, Zaire improved with high coverage and use of medium titre Edmonston Zagreb vaccine at age 6 months.

BACKGROUND: To improve measles control in Kinshasa, Zaire, a project to increase vaccine coverage was begun in 1988, and in 1989, the city vaccination programme changed measles vaccination policy from Schwartz vaccine at age 9 months to medium titre Edmonston Zagreb (EZ) vaccine at age 6 months. We report the impact of the programme on measles incidence and mortality. METHODS: Data on vaccine coverage were obtained from cluster sample surveys conducted every 1-2 years and from routine reports of vaccine doses administered. Data on measles incidence and mortality were obtained from sentinel surveillance sites. The serological response to EZ measles vaccine was evaluated at a health centre in 1989 and in a community survey in 1990. RESULTS: Measles vaccine coverage estimated in cluster surveys increased from 50% of the 1984 birth cohort to 89% of the 1989 birth cohort, accepting either a home-based record or a verbal history of vaccination. Reported measles incidence per 10,000 [corrected] population decreased by over 90%, from 37.5 in 1980 (early vaccination years) to 1.6 in 1991. There was a relative decrease in the proportion of cases aged < 9 months (32% of cases in 1986-1987 and 23% of cases in 1990-1991) and an increase in the proportion aged > 23 months (29% of cases in 1986-1987 and 43% in 1990-1991). According to ELISA assays, 74-76% of children seroresponded to EZ vaccine administered at age 6-7 months under routine programme conditions. CONCLUSIONS: Measles can be controlled in urban areas, although it is difficult to determine how great a contribution vaccination at age 6 months makes over and above the achievement of high coverage.

Antibodies, Viral↗
PubMed1994

Successes and failures in measles control.

The Expanded Programme on Immunization (EPI) of the World Health Organization has a global target of reducing measles incidence by 90% and mortality by 95% from pre-EPI levels by 1995. Both developed and developing countries that have given priority to measles control have substantially reduced measles morbidity and mortality, and some have come close to eliminating measles. A variety of vaccination schedules and strategies have been used, which reflect the differing program goals, health services infrastructure, and availability of resources in different countries. Failure to control measles has usually been due to a failure to implement planned strategies adequately. The highest priority in measles control is to assist countries, especially the lowest-income countries, to implement vaccination programs more effectively.

Developing Countries↗
PubMed1994

Measles control in Maputo, Mozambique, using a single dose of Schwarz vaccine at age 9 months.

In Maputo city, immunization is available at government health facilities, all contacts being used to vaccinate children. Door-to-door mobilization is conducted to identify eligible children and refer them for immunization. Card-documented measles vaccine coverage, estimated by community surveys, rose from 48% in 1982 to 86% in 1986 and 92% in 1992. The median age at measles vaccination was 10.2 months in 1986 and 9.2 months in 1992. The reported measles incidence rates per 100,000 population fell by 92% from 569 in 1977-78 (pre-vaccination) to 44 in 1990-92, and the reported inpatient measles mortality fell from 19.8 to 0.7 per 100,000. Among children whose age at measles onset was known, the proportion of reported measles cases in children under 9 months of age fell from 2162 (20.3% of 10,636 cases) in 1982-85 to 1695 (17.8% of 9501 cases) in 1986-92. The proportion of cases in children aged > or = 5 years increased from 15.2% to 32.8% in the corresponding periods. The global goals for measles control can be achieved by a single dose of Schwarz vaccine at 9 months of age.

Child, Preschool↗