Population-Level Risk Factors Related to Measles Case Fatality: A Conceptual Framework Based on Expert Consultation and Literature Review

A better understanding of population-level factors related to measles case fatality is needed to estimate measles mortality burden and impact of interventions such as vaccination. This study aimed to develop a conceptual framework of mechanisms associated with measles case fatality ratios (CFRs) and assess the scope of evidence available for related indicators. Using expert consultation, we developed a conceptual framework of mechanisms associated with measles CFR and identified population-level indicators potentially associated with each mechanism. We conducted a literature review by searching PubMed on 31 October 2021 to determine the scope of evidence for the expert-identified indicators. Studies were included if they contained evidence of an association between an indicator and CFR and were excluded if they were from non-human studies or reported non-original data. Included studies were assessed for study quality. Expert consultation identified five mechanisms in a conceptual framework of factors related to measles CFR. We identified 3772 studies for review and found 49 studies showing at least one significant association with CFR for 15 indicators (average household size, educational attainment, first- and second-dose coverage of measles-containing vaccine, human immunodeficiency virus prevalence, level of health care available, stunting prevalence, surrounding conflict, travel time to major city or settlement, travel time to nearest health care facility, under-five mortality rate, underweight prevalence, vitamin A deficiency prevalence, vitamin A treatment, and general malnutrition) and only non-significant associations for five indicators (antibiotic use for measles-related pneumonia, malaria prevalence, percent living in urban settings, pneumococcal conjugate vaccination coverage, vitamin A supplementation). Our study used expert consultation and a literature review to provide additional insights and a summary of the available evidence of these underlying mechanisms and indicators that could inform future measles CFR estimations.

Implementing WHO guidance on conducting and analysing vaccination coverage cluster surveys: Two examples from Nigeria

In 2015, the World Health Organization substantially revised its guidance for vaccination coverage cluster surveys (revisions were finalized in 2018) and has since developed a set of accompanying resources, including definitions for standardized coverage indicators and software (named the Vaccination Coverage Quality Indicators—VCQI) to calculate them.–The current WHO vaccination coverage survey manual was used to design and conduct two nationally representative vaccination coverage surveys in Nigeria–one to assess routine immunization and one to measure post-measles campaign coverage. The primary analysis for both surveys was conducted using VCQI. In this paper, we describe those surveys and highlight some of the analyses that are facilitated by the new resources. In addition to calculating coverage of each vaccine-dose by age group, VCQI analyses provide insight into several indicators of program quality such as crude coverage versus valid doses, vaccination timeliness, missed opportunities for simultaneous vaccination, and, where relevant, vaccination campaign coverage stratified by several parameters, including the number of previous doses received. The VCQI software furnishes several helpful ways to visualize survey results. We show that routine coverage of all vaccines is far below targets in Nigeria and especially low in northeast and northwest zones, which also have highest rates of dropout and missed opportunities for vaccination. Coverage in the 2017 measles campaign was higher and showed less geospatial variation than routine coverage. Nonetheless, substantial improvement in both routine program performance and campaign implementation will be needed to achieve disease control goals.

Supplemental measles vaccine antibody response among HIV-infected and -uninfected children in Malawi after 1- and 2-dose primary measles vaccination schedules

Background

The long-term antibody response to measles vaccine (MV) administered at age 6 months with or without subsequent doses is not well documented.

Methods

Measles serum antibody responses were evaluated after a supplemental dose of measles vaccine (sMV) administered at a median age of 20 months among Malawian children who had previously received 2 doses of measles vaccine (MV) at ages 6 and 9 months (HIV-infected and random sample of HIV-uninfected) or 1 dose at age 9 months (random sample of HIV-uninfected). We compared measles antibody seropositivity between groups by enzyme linked immunoassay and seroprotection by plaque reduction neutralization geometric mean concentrations.

Results

Of 1756 children enrolled, 887 (50.5%) received a sMV dose following MV at 9 months of age and had specimens available after sMV receipt, including 401 HIV-uninfected children who received one MV dose at 9 months, 464 HIV-uninfected and 22 HIV-infected children who received two doses of MV at ages 6 and 9 months. Among HIV-uninfected children, protective levels of antibody were found post sMV in 90–99% through ages 24–36 months and were not affected by MV schedule. Geometric mean concentration levels of measles antibody were significantly increased post-sMV among those HIV-uninfected children previously non-responsive to vaccination. Among HIV-infected children, the proportion seroprotected increased initially but by 9 months post-sMV was no higher than pre-sMV.

Conclusions

Our findings support early 2-dose MV to provide measles immunity for young infants without risk of interference with antibody responses to subsequent MV doses administered as part of SIAs.

Efficacy of different pneumococcal conjugate vaccine schedules against pneumonia, hospitalisation, and mortality: re-analysis of a randomised trial in the Gambia

BACKGROUND

Pneumococcal conjugate vaccines (PCV) reduce disease due to Streptococcus pneumoniae. We aimed to determine the efficacy of different PCV schedules in Gambian children.

METHODS

We reanalysed data from a randomised placebo-controlled trial. Infants aged 6-51 weeks were allocated to three doses of nine-valent PCV (n=8718) or placebo (n=8719) and followed until age 30 months. We categorised participants to compare: (a) a first dose at age 6 or 10 weeks, (b) intervals of 1 or 2 months between doses, and (c) different intervals between second and third doses. The primary endpoint was first episode of radiologic pneumonia; other endpoints were hospitalisation and mortality. Using the placebo group as the reference population, Poisson regression models were used with follow-up after the first dose to estimate the efficacy of each schedule and from age 6 weeks to estimate the incidence rate difference between schedules.

RESULTS

Predicted efficacy in the groups aged 6 weeks (n=2467, 154 events) or 10 weeks (n=2420, 106 events) at first dose against radiologic pneumonia were 32% (95% CI 19-43%) and 33% (95% CI 21-44%), against hospitalisation 14% (95% CI 3-23%) and 17% (95% CI 7-26%), and against mortality 17% (95% CI -3 to 33%) and 16% (95% CI -3 to 32%) respectively. Predicted efficacy in the groups with intervals of 1 month (n=2701, 133 events) or 2 months (n=1351, 58 events) between doses against radiologic pneumonia were 33% (95% CI 20-44%) and 36% (95% CI 24-46%), against hospitalisation 15% (95% CI 5-24%) and 18% (95% CI 8-27%), and against mortality 17% (95% CI -2 to 33%) and 13% (95% CI -8 to 29%) respectively. Efficacy did not differ by interval between second and third doses, nor did the incidence rate difference between schedules.

CONCLUSIONS

We found no evidence that efficacy or effectiveness of PCV9 differed when doses were given with modest variability around the scheduled ages or intervals between doses.

Persistence of vaccine-induced measles antibody beyond age 12 months: a comparison of response to one and two doses of Edmonston-Zagreb measles vaccine among HIV-infected and uninfected children in Malawi

BACKGROUND

Previously, we demonstrated that measles antibody prevalence was lower at age 12 months among children infected with human immunodeficiency virus (HIV) than uninfected children following measles vaccination (MV) at ages 6 and 9 months. Among HIV-uninfected children, measles antibody prevalence was lower among 1- than 2-dose MV recipients. Here, we report results through age 24 months.

METHODS

Children born to HIV-infected mothers received MV at 6 and 9 months, and children of HIV-uninfected mothers were randomized to MV at 6 and 9 months or MV at 9 months. We followed children through age 24 months. The child's HIV status was determined and measles immunoglobulin G (IgG) level was measured by enzyme immunoassay (EIA) and by plaque reduction neutralization (PRN) on a subset.

RESULTS

Among HIV-uninfected children, the difference in measles antibody prevalence at age 12 months between one- and two-dose recipients reported previously by EIA was shown to be smaller by PRN. By age 24 months, 84% and 87% of HIV-uninfected children receiving 1 or 2 doses, respectively, were seroprotected. Only 41% of 22 HIV-infected children were measles seroprotected at age 20 months.

DISCUSSION

Measles seroprotection persisted through age 24 months among HIV-uninfected children who received 1 or 2 doses of MV. HIV-infected children demonstrated seroprotection through age 12 months, but this was not sustained.

Association of serotype with risk of death due to pneumococcal pneumonia: a meta-analysis

BACKGROUND

The 92 capsular serotypes of Streptococcus pneumoniae differ greatly in nasopharyngeal carriage prevalence, invasiveness, and disease incidence. There has been some debate, though, regarding whether serotype independently affects the outcome of invasive pneumococcal disease (IPD). Published studies have shown variable results with regard to case-fatality ratios for specific serotypes and the role of host factors in affecting these relationships. We evaluated whether risk of death due to IPD is a stable serotype-associated property across studies and then compared the pooled effect estimates with epidemiologic and biological correlates.

METHODS

We performed a systematic review and meta-analysis of serotype-specific disease outcomes for patients with pneumonia and meningitis. Study-specific estimates of risk of death (risk ratio [RR]) were pooled from 9 studies that provided serotype-specific data on pneumonia and meningitis using a random-effects method with serotype 14 as the reference. Pooled RRs were compared with RRs from adults with low comorbidity scores to evaluate potential confounding by host factors.

RESULTS

Significant differences were found in the RR estimates among serotypes in patients with bacteremic pneumonia. Overall, serotypes 1, 7F, and 8 were associated with decreased RRs, and serotypes 3, 6A, 6B, 9N, and 19F were associated with increased RRs. Outcomes among meningitis patients did not differ significantly among serotypes. Serotypes with increased RRs had a high carriage prevalence, had low invasiveness, and were more heavily encapsulated in vitro.

CONCLUSIONS

These results suggest that IPD outcome, like other epidemiologic measures, is a stable serotype-associated property.

Estimation of intervention effects using first or multiple episodes in clinical trials: The Andersen-Gill model re-examined

Randomized trials of interventions against infectious diseases are often analyzed using data on first or only episodes of disease, even when subsequent episodes have been recorded. It is often said that the Andersen-Gill (AG) model gives a biased estimate of intervention effect if there is event dependency over time. We demonstrate that, in the presence of event dependency, an effective intervention may have an indirect effect on disease risk at time t(j) via its direct effect on disease risk at time t(i), i<j, and that the AG model estimates the total effect instead of the direct effect alone. From a clinical and public health perspective, estimation of the total effect is important. Previous simulation studies showed contradictory results about the performance of the AG model in the presence of unobserved heterogeneity across individuals. We show that some of the previous studies unintentionally created informative censoring in their data generating process by including only a certain maximum number of events per individual. We re-ran some previous simulations with and without altering this maximum. With reference to the situations often seen in pneumococcal vaccine trials, we evaluated the performance of the Cox model for time to first episode and the AG model for multiple episodes. We applied these models to re-analyze data from a pneumococcal conjugate vaccine trial. We maintain that a careful clarification of research purpose is needed before one can choose a statistical model, and that the AG model is useful in the estimation of the total effect of an intervention.

HIV-1 infection in Zambian children impairs the development and avidity maturation of measles virus-specific immunoglobulin G after vaccination and infection

BACKGROUND

Endemic transmission of measles continues in many countries that have a high human immunodeficiency virus (HIV) burden. The effects that HIV infection has on immune responses to measles and to measles vaccine can impact measles elimination efforts. Assays to measure antibody include the enzyme immunoassay (EIA), which measures immunoglobulin G (IgG) to all measles virus (MV) proteins, and the plaque reduction neutralization (PRN) assay, which measures antibody to the hemagglutinin and correlates with protection. Antibody avidity may affect neutralizing capacity.

METHODS

HIV-infected and HIV-uninfected Zambian children were studied after measles vaccination (n=44) or MV infection (n=57). Laboratory or wild-type MV strains were used to infect Vero or Vero/signaling lymphocyte-activation molecule (SLAM) cells in PRN assays. IgG to MV was measured by EIA, and avidity was determined by ammonium thiocyanate dissociation.

RESULTS

HIV infection impaired EIA IgG responses after vaccination and measles but not PRN responses measured using laboratory-adapted MV. Avidity was lower among HIV-infected children 3 months after vaccination and 1 and 3 months after measles. Neutralization of wild-type MV infection of Vero/SLAM cells correlated with IgG avidity.

CONCLUSION

Lower antibody quality and quantity in HIV-infected children after measles vaccination raise challenges for assuring the long-term protection of these children. Antibody quality in children receiving antiretroviral therapy requires assessment.

Seasonality and outbreak of a predominant Streptococcus pneumoniae serotype 1 clone from The Gambia: expansion of ST217 hypervirulent clonal complex in West Africa

Background

Streptococcus pneumoniae serotype 1 causes > 20% of invasive disease, among all age groups combined, in The Gambia. In contrast, it is rarely detected in carriage studies. This study compares the molecular epidemiology of S. pneumoniae serotype 1 causing invasive disease in The Gambia between 1996 and 2005 to those carried in the nasopharynx between 2004 and 2006.

Results

A total of 127 invasive and 36 nasopharyngeal carriage serotype 1 isolates were recovered from individuals of all age groups and were analyzed by serotyping, antibiotic susceptibility testing and MLST. MLST analysis revealed 23 different sequence types (STs), 18 of which were novel. The most prevalent clone among the 163 isolates was ST618 (70.5%), followed by ST3575 (7.4%), ST2084 (2.5%) and ST612 (2.5%). A single ST (ST618), previously shown to belong to the ST217 hypervirulent clonal complex, was frequent among carriage (61.1%) and invasive (72.7%) serotype 1 isolates. ST618 causing both paediatric and adult disease peaked annually in the hot dry season and caused outbreak in 1997 and 2002.

Conclusion

For over a decade, isolates of ST618 have been the dominant lineage among serotype 1 carriage and disease isolates circulating in the Gambia. This lineage shows similar epidemiological features to those of the meningococcus in the African meningitis belt being able to cause outbreaks of disease

Molecular epidemiology of pneumococci obtained from Gambian children aged 2-29 months with invasive pneumococcal disease during a trial of a 9-valent pneumococcal conjugate vaccine

Background

The study describes the molecular epidemiology of Streptococcus pneumoniae causing invasive disease in Gambian children

Methods

One hundred and thirty-two S. pneumoniae isolates were recovered from children aged 2–29 months during the course of a pneumococcal conjugate vaccine trial conducted in The Gambia of which 131 were characterized by serotyping, antibiotic susceptibility, BOX-PCR and MLST.

Results

Twenty-nine different serotypes were identified; serotypes 14, 19A, 12F, 5, 23F, and 1 were common and accounted for 58.3% of all serotypes overall. MLST analysis showed 72 sequence types (STs) of which 46 are novel. eBURST analysis using the stringent 6/7 identical loci definition, grouped the isolates into 17 clonal complexes and 32 singletons. The population structure of the 8 serotype 1 isolates obtained from 4 vaccinated and 2 unvaccinated children were the same (ST 618) except that one (ST3336) of the isolates from an unvaccinated child had a novel ST which is a single locus variant of ST 618.

Conclusion

We provide the first background data on the genetic structure of S. pneumoniae causing IPD prior to PC7V use in The Gambia. This data will be important for assessing the impact of PC7V in post-vaccine surveillance from The Gambia.

Ensuring access to HPV vaccines through integrated services: a reproductive health perspective

In 2006, a quadrivalent human papillomavirus (HPV) vaccine was licensed, and another vaccine may be licensed soon. Little is known about the practical considerations involved in designing and implementing cervical cancer prevention programmes that include vaccination as a primary means of prevention. Although the vaccine may ultimately be indicated for both males and females, young girls, or girls and women aged 9-25 years, will be the initial candidates for the vaccine. This paper describes avenues for service delivery of HPV vaccines and critical information gaps that must be bridged in order to inform future sexual and reproductive health programming. It proposes the role that the sexual and reproductive health community, together with immunization and cancer control programmes, could have in supporting the introduction of HPV vaccines within the context of current health systems.

HIV-1 infection as a risk factor for incomplete childhood immunization in Zambia

Immunizations are of particular importance for human immunodeficiency virus type 1(HIV-1)-infected children as they are at increased risk of severe disease and death from several vaccine-preventable diseases. Outside the United States, however, research on the impact of the HIV-1 epidemic on childhood immunization coverage is sparse. We conducted a nested case-control study in hospitalized children with measles to assess whether HIV-1 infection was a risk factor for incomplete immunization with diphtheria-tetanus-pertussis vaccine (DTP) and oral polio vaccine (OPV). Of 473 children, whose immunization status was determined from the immunization record or maternal recall, 23% were incompletely immunized and 19% were HIV-1 infected. After adjusting for age, sex, and measles vaccination status, HIV-1 infection was significantly associated with incomplete immunization with DTP and OPV (adjusted OR 1.9; 95% CI 1.1, 3.3). In a subset of children for whom information on maternal education was available, less than 7 years of school education was a risk factor for incomplete immunization (adjusted OR 3.7; 95% CI 1.8. 7.5). Children from homes with more than three children were twice as likely to be incompletely immunized as those from homes with one to three children. Our findings suggest that HIV-1-infected children are at increased risk of vaccine-preventable diseases not only because of impaired immune responses but because of lower rates of vaccine coverage.

Chapter 15: HPV vaccine use in the developing world

Human papillomavirus (HPV)-related morbidity and mortality from cervical cancer primarily occurs in the developing world, where, unfortunately, access to vaccines in general, and expensive newer vaccines in particular, is often more limited than in the industrialized world. In addition, secondary prevention methods such as HPV screening, Pap testing, or visual inspection are uncommon in the developing world. The HPV vaccine will be first introduced into the industrialized countries and it will then, over the course of time, become used in the developing countries. HPV vaccine should be introduced in the framework of comprehensive cervical cancer control, and offers an opportunity to bring together a wide range of constituents who have not to date worked closely on vaccination. Ultimately, the decision of whether and when a vaccine will be introduced will depend on individual countries. To prepare for decisions on HPV vaccine use, the sexual and reproductive health (SRH; including adolescent health), immunization, and cancer control communities need to work together to analyze the appropriate data and build international and national consensus. The timeframe for other newer vaccines, such as hepatitis B and Hib, has been measured in decades, and the challenge to the public sector is to greatly shorten the time needed to make HPV vaccines available and affordable for the developing world, where their impact will be greatest.

Evaluating the impact of the HIV pandemic on measles control and elimination

OBJECTIVE

To estimate the impact of the HIV pandemic on vaccine-acquired population immunity to measles virus because high levels of population immunity are required to eliminate transmission of measles virus in large geographical areas, and HIV infection can reduce the efficacy of measles vaccination.

METHODS

A literature review was conducted to estimate key parameters relating to the potential impact of HIV infection on the epidemiology of measles in sub-Saharan Africa; parameters included the prevalence of HIV, child mortality, perinatal HIV transmission rates and protective immune responses to measles vaccination. These parameter estimates were incorporated into a simple model, applicable to regions that have a high prevalence of HIV, to estimate the potential impact of HIV infection on population immunity against measles.

FINDINGS

The model suggests that the HIV pandemic should not introduce an insurmountable barrier to measles control and elimination, in part because higher rates of primary and secondary vaccine failure among HIV-infected children are counteracted by their high mortality rate. The HIV pandemic could result in a 2-3% increase in the proportion of the birth cohort susceptible to measles, and more frequent supplemental immunization activities (SIAs) may be necessary to control or eliminate measles. In the model the optimal interval between SIAs was most influenced by the coverage rate for routine measles vaccination. The absence of a second opportunity for vaccination resulted in the greatest increase in the number of susceptible children.

CONCLUSION

These results help explain the initial success of measles elimination efforts in southern Africa, where measles control has been achieved in a setting of high HIV prevalence.

Neonatal measles immunity in rural Kenya: the influence of HIV and placental malaria infections on placental transfer of antibodies and levels of antibody in maternal and cord serum samples

INTRODUCTION

Young infants are protected from measles infection by maternal measles antibodies. The level of these antibodies at birth depends on the level of antibodies in the mother and the extent of placental transfer. We investigated predictors of levels of measles antibodies in newborns in rural Kenya.

METHODS

A total of 747 paired maternal-cord serum samples (91 from human immunodeficiency virus [HIV]-infected and 656 from HIV-uninfected mothers) were tested for measles immunoglobulin G antibodies. Placental malaria infection was determined by biopsy. Data on pregnancy history, gestational age, and anthropometric and socioeconomic status were collected.

RESULTS

Infants born to HIV-infected mothers were more likely (odds ratio, 4.6 [95% confidence interval {CI}, 2.2-9.7]) to be seronegative and had 35.1% (95% CI, 9.8%-53.2%) lower levels of measles antibodies than did those born to HIV-uninfected mothers. Preterm delivery, early maternal age, and ethnic group were also associated with reduced levels of measles antibodies. There was little evidence that placental malaria infection was associated with levels of measles antibodies in newborns.

CONCLUSION

Our results suggest that maternal HIV infection may reduce levels of measles antibodies in newborns. Low levels of measles antibodies at birth render children susceptible to measles infection at an early age. This is of concern in sub-Saharan African countries, where not only is the prevalence of HIV high, but measles is the cause of much morbidity and mortality.

Cost of delivering child immunization services in urban Bangladesh: a study based on facility-level surveys

This facility-based study estimated the costs of providing child immunization services in Dhaka, Bangladesh, from the perspective of healthcare providers. About a quarter of all immunization (EPI) delivery sites in Dhaka city were surveyed during 1999. The EPI services in urban Dhaka are delivered through a partnership of the Government of Bangladesh (GoB) and non-governmental organizations (NGOs). About 77% of the EPI delivery sites in Dhaka were under the management of NGOs, and 62% of all vaccinations were provided through these sites. The outreach facilities (both GoB and NGO) provided immunization services at a much lower cost than the permanent static facilities. The average cost per measles-vaccinated child (MVC), an indirect measure of number of children fully immunized (FIC-the number of children immunized by first year of life), was 11.61 U.S. dollars. If all the immunization doses delivered by the facilities were administered to children who were supposed to be immunized (FVC), the cost per child would have been 6.91 U.S. dollars. The wide gap between the cost per MVC and the cost per FVC implies that the cost of immunizing children can be reduced significantly through better targeting of children. The incremental cost of adding new services or interventions with current EPI was quite low, not significantly higher than the actual cost of new vaccines or drugs to be added. NGOs in Dhaka mobilized about 15,000 U.S. dollars from the local community to support the immunization activities. Involving local community with EPI activities not only will improve the sustainability of the programme but will also increase the immunization coverage.

Incidence and risk factors of paediatric rotavirus diarrhoea in northern Ghana

We measured the type-specific incidence of paediatric rotavirus diarrhoea in an area of northern Ghana. Over 1 year, diarrhoea 1717 episodes were identified, of which 677 (39%) were positive for rotavirus. Risk factors for rotavirus infection included old age, wasting, high Vesikari score and the episode occurring in the dry season. Rotavirus-positive episodes tended to be more acute, causing vomiting and greater dehydration, and were more likely to require hospitalization. The incidence was 0.089 episodes per person-year for all diarrhoea, and 0.035 for rotavirus diarrhoea. The observed incidence decreased markedly with distance from the nearest health centre, suggesting a large unobserved burden. G2P[6], G3P[4] and G9P[8] made up more than half the genotypes detected, but the remainder were diverse. There is a large burden of rotavirus diarrhoea, but the effectiveness of future vaccines could be diluted by the high polymorphism of the virus, and the difficulty of reaching remote populations.

Changing patterns of rotavirus genotypes in ghana: emergence of human rotavirus G9 as a major cause of diarrhea in children

Genotyping of human rotaviruses was performed on 312 rotavirus-positive samples collected from 2,205 young children with diarrhea in the Upper East District of Ghana, a rural community. Of the 271 (86.9%) rotavirus strains that could be VP7 (G) or VP4 (P) characterized, 73 (26.9%) were of G9 specificity. The predominant G9 genotype was G9P[8], which constituted 79.5% of all G9 strains detected, followed by G9P[6] (12.3%), G9P[10] (2.7%), and G9P[4] (1.3%). G9 strains with mixed P types constituted 2.7% of all G9 strains found in the study. All the G9P[8] strains had a long RNA electrophoretic pattern with VP6 subgroup II specificity. Four G9 isolates, GH1319, GH1416, GH3550, and GH3574, which were selected based on the abundance of stool material and were representative of the three electropherotypes observed, were cloned and sequenced. The Ghanaian isolates shared more than 98% sequence nucleotide homology with other G9 strains from the United States (US1205), Malawi (MW69), Brazil (R160), Japan (95H115), and Nigeria (Bulumkutu). However, they showed only 95% nucleotide homology with the Thai G9 strain Mc345. Phylogenetic analysis of the nucleic acid sequence revealed the existence of at least three clusters, with Ghanaian strains forming one cluster, Nigerian and Brazilian strains forming a second cluster, and U.S., Malawian, and Japanese strains forming a third.

Effects of misclassification of causes of death on the power of a trial to assess the efficacy of a pneumococcal conjugate vaccine in The Gambia

BACKGROUND

A reduction in cause-specific mortality may be the most important public health measure of the efficacy of a new vaccine. However, in developing countries, assignment of causes of deaths occurring outside hospitals can be assessed often only through the questioning of relatives about the signs and symptoms leading to death ('post-mortem questionnaire'). Causes assigned in this way have poor sensitivity and specificity. We illustrate the effects of this misclassification on the power of a large trial of a pneumococcal polysaccharide/protein conjugate vaccine with a mortality endpoint.

METHODS

Required sample sizes to achieve a study with specified power were calculated for all-cause and acute lower respiratory tract infection (ALRI) mortality for different levels of sensitivity and specificity of post-mortem questionnaires. Data from active community-based surveillance and post-mortem questionnaires collected 1989-1993 from the study area were used in the calculations.

FINDINGS

The mortality rate among children aged 6-29 months from all causes was 34.2 per 1000 child-years; 19% of deaths were attributable to ALRI. Assuming that pneumococci would be responsible for 50% of ALRI deaths and that the vaccine would cover 70% of disease serotypes and would be 90% effective against these serotypes, the expected efficacy of the vaccine would be 6.0% (19% x 50% x 70% x 90%) against all causes combined and 31.5% (50% x 70% x 90%) against deaths from ALRI. If, as suggested by various reports, the sensitivity and specificity of assigning a death to ALRI by post-mortem questionnaire are about 40% and 90% respectively, then the observed vaccine efficacy against ALRI (as classified using the post-mortem questionnaire) would fall to 20%, and the power to detect this would be reduced by approximately 40%. Furthermore, low sensitivity of diagnosis would lead to a falsely low estimate of the burden of ALRI mortality in the population and the trial might have greater power to detect a reduction in mortality from all causes combined than that estimated at the outset.

CONCLUSIONS

Low sensitivity and specificity of diagnosis by post-mortem questionnaire may mean that the power of a trial to detect a reduction in all-cause mortality is similar to that to detect a reduction in ALRI mortality. Since the latter is more susceptible to bias from misclassification of cause of death, all-cause mortality may be the most suitable endpoint. Similar considerations apply to trials of interventions against other diseases for which a cause-specific endpoint is subject to substantial misclassification.

Efficacy of polysaccharide pneumococcal vaccine in adults in more developed countries: the state of the evidence

We review studies on the efficacy against disease caused by Streptococcus pneumoniae of the 23-valent polysaccharide pneumococcal vaccine in adult populations in the more developed countries. Meta-analyses of primary vaccine trials have attempted to reduce uncertainty from lack of power. Vaccine efficacy calculated from studies in South African gold-miners and in Papua New Guinea, with high attack rates and differing serotype patterns, cannot automatically be applied to more developed countries. Meta-analyses will overestimate a protective effect if this clinical heterogeneity is ignored. Meta-analyses limited to trials in the more developed setting show no protective effect against pneumococcal pneumonia and a non-significant protective effect against bacteraemia. Lack of a specific diagnosis limits the ability to detect a protective effect against pneumococcal pneumonia. Most, but not all, observational studies confirm a protective effect against bacteraemia. An effect on mortality in more developed countries has yet to be documented.

Prospective study of measles in hospitalized, human immunodeficiency virus (HIV)-infected and HIV-uninfected children in Zambia

Measles in persons coinfected with human immunodeficiency virus (HIV) has been reported to be unusual in its presentation and frequently fatal. To determine the effect of HIV coinfection on the clinical features and outcome of measles, a prospective study of hospitalized children with measles was conducted between January 1998 and October 2000 in Lusaka, Zambia. One-sixth (17%) of 546 children hospitalized with laboratory-confirmed measles were coinfected with HIV. One-third of the HIV-infected children hospitalized with confirmed measles were <9 months old, compared with 23% of HIV-uninfected children (P=.03). Few differences in clinical manifestations, complications, or mortality were found between HIV-infected and HIV-uninfected children with measles. HIV-infected children constitute a significant proportion of children hospitalized with measles in countries with high HIV prevalence and are more likely to be younger than the age for routine measles immunization.

Suppression of human immunodeficiency virus replication during acute measles

To determine the effect of measles virus coinfection on plasma human immunodeficiency virus (HIV) RNA levels, a prospective study of hospitalized children with measles was conducted between January 1998 and October 2000 in Lusaka, Zambia. Plasma HIV RNA levels were measured during acute measles and 1 month after hospital discharge. The median plasma HIV RNA level in 33 children with measles who were followed longitudinally was 5339 copies/mL at study entry, 60,121 copies/mL at hospital discharge, and 387,148 copies/mL at 1-month follow-up. The median plasma HIV RNA level in children without acute illness was 228,454 copies/mL. Plasma levels of immune activation markers were elevated during the period of reduced plasma HIV RNA. Plasma levels of several potential HIV suppressive factors also were elevated during acute measles. HIV replication is transiently suppressed during acute measles at a time of intense immune activation.

Malaria in pregnancy: adverse effects on haemoglobin levels and birthweight in primigravidae and multigravidae

BACKGROUND

In areas of endemic transmission, malaria in pregnancy is associated with severe maternal anaemia and low birthweight babies. The prevalence of infection is highest in primigravidae (PG), and hence control efforts are usually geared towards this high risk group. Using a sensitive measure of placental infection, we investigated the relationship between active-acute, active-chronic and past placental infection with maternal anaemia and low birthweight in women of all gravidities.

METHODS

Between January 1996 and July 1997, 912 women delivering in Kilifi District Hospital, Kenya, were recruited. Haemoglobin and peripheral malaria slides were taken prior to delivery, placental biopsies and smears were taken at the time of delivery and birthweight and maternal height and weight were measured soon after birth. Information was obtained on socio-economic and educational status. The association between placental malaria, severe anaemia and low birthweight was investigated for women of different gravidities.

FINDINGS

By placental histology, the prevalence of active or past malaria in all gravidities was high, ranging from 64% in PG to 30% in gravidities 5 and above. In gravidities 1-4, active malaria infection was associated with severe maternal anaemia, adjusted OR 2.21 (95% CI 1.36, 3.61). There was a significant interaction between chronic or past malaria and severe anaemia in their effects on birthweight, whereby the risk of low birthweight was very high in women with both chronic or past placental malaria and severe anaemia: OR 4.53 (1.19, 17.2) in PG; 13.5 (4.57, 40) in gravidities 2-4.

INTERPRETATION

In this area of moderate malaria transmission, women of all parities have substantially increased risk of low birthweight and severe anaemia as a result of malaria infection in pregnancy. The risk of low birthweight is likely to be particularly high in areas with a high prevalence of severe anaemia.

Rotavirus G and P genotypes in rural Ghana

An epidemiological study of rotavirus infection was conducted on specimens collected from patients with gastroenteritis and domiciled in the rural Upper Eastern Region of Ghana during 1998. Fifty isolates, randomly selected from 165 human group A rotavirus-positive samples, were G and P characterized by a reverse transcription (RT)-PCR assay using a seminested multiplex method. Rotaviruses of the G3 genotype were found to be the predominant strain (78%), followed by G2 (14%) and G1 (2%). Mixed infections, as shown by combinations of G3 and G2 (4%) and G3 and G1 (2%), were also observed. P typing showed P[4] (72.34%) to be the prevalent strain, followed by P[6] (21.3%), P[8] (2.13%), and a combination of P[4] and P[6] (4.3%).

Prolonged measles virus shedding in human immunodeficiency virus-infected children, detected by reverse transcriptase-polymerase chain reaction

A reverse transcriptase-polymerase chain reaction assay was used to detect measles virus RNA in peripheral blood mononuclear cells, urine, and nasopharyngeal specimens from Zambian children during hospitalization and approximately 1-2 months after discharge. Of 47 children, 29 (61.7%) had prolonged measles virus shedding, as defined by detection of measles virus RNA in > or =1 specimen obtained 30-61 days after rash onset. Ten (90.9%) of 11 human immunodeficiency virus (HIV)-infected children had prolonged measles virus shedding, compared with 19 (52.8%) of 36 HIV-uninfected children (P=.02). Prolonged measles virus shedding did not correlate with levels of measles virus-specific antibody. HIV-infected children with measles may have a prolonged infectious period that potentially enhances measles virus transmission and hinders measles control.

Respiratory syncytial virus: an underestimated cause of respiratory infection, with prospects for a vaccine

Respiratory syncytial virus (RSV) infects most people by the time they are 2 years old and reinfects throughout life. RSV is best recognised for causing bronchiolitis in infants--it is one of the most important respiratory pathogens in childhood in industrialised countries. The clinical manifestations of RSV infection in adults and elderly people, from upper respiratory tract infection to pneumonia, are less well known. Part of the burden of winter mortality in elderly people is attributable to RSV infection and it may be as important a cause of death as influenza. Recent advances in RSV vaccines have made RSV a more important topic for epidemiological research and surveillance. Basic research required before vaccine programmes can be developed includes describing the natural history of RSV infection in adults, quantifying the burden of disease attributable to RSV, and defining the best surveillance methods with which to evaluate different vaccination strategies.

Implications of the human immunodeficiency virus epidemic for control and eradication of measles

Human immunodeficiency virus (HIV)-infected persons may be important, unrecognized transmitters of measles virus, thwarting eradication efforts. We reviewed the published English-language literature on measles and measles immunization in HIV-infected persons to investigate the clinical features of measles, the responses to measles immunization, and the safety of measles vaccine in HIV-infected persons and, conversely, the effect of measles and measles immunization on HIV infection. HIV-infected persons with measles are likely to have uncharacteristic clinical findings and severe illness, with high rates of pneumonitis and death. Primary and secondary failure of measles vaccine in HIV-infected children may permit transmission of measles virus in spite of high rates of immunization coverage. A factor that complicates measles-control efforts in areas of high prevalence of HIV is the potential for fatal infection with measles vaccine virus. Further research on the impact of the HIV epidemic on measles and measles immunization is necessary to guide strategies for the eradication of measles.

Intermittent sulphadoxine-pyrimethamine to prevent severe anaemia secondary to malaria in pregnancy: a randomised placebo-controlled trial

BACKGROUND

In areas of endemic transmission, malaria in pregnancy is associated with severe maternal anaemia and low-birthweight babies. We studied the efficacy of intermittent treatment doses of sulphadoxine-pyrimethamine in preventing malaria and severe anaemia in pregnancy in a double-blind placebo-controlled trial among primigravid women living in Kilifi District, Kenya.

METHODS

Between January, 1996, and April, 1997, 1264 primigravid women were recruited when they attended for antenatal care, and randomly assigned sulphadoxine-pyrimethamine (640) or placebo (624). Women received one, two, or three doses of study medication depending on the duration of gestation at enrolment. Primary outcome measures were severe anaemia (haemoglobin <8 g/dL) and malaria parasitaemia, assessed at 34 weeks of gestation. Analyses were based on intention to treat among women who had study blood tests at 34 weeks.

FINDINGS

30 (5.3%) of 567 women in the sulphadoxine-pyrimethamine group and 199 (35.3%) of 564 in the placebo group had peripheral parasitaemia (protective efficacy 85% [95% CI 78-90], p<0.0001). 82 (14.5%) and 134 (23.7%) had severe anaemia (protective efficacy 39% [22-52], p<0.0001). Even women who booked late and received only one dose of sulphadoxine-pyrimethamine benefited significantly from the intervention. The effects were seen both in women who owned insecticide-treated bednets and in women who did not.

INTERPRETATION

Intermittent presumptive treatment with sulphadoxine-pyrimethamine is an effective, practicable strategy to decrease the risk of severe anaemia in primigravidae living in malarious areas.

Comparison of a commercial enzyme immunoassay with plaque reduction neutralization for maternal and infant measles antibody measurement

The most practicable assay for measurement of measles IgG (mIgG) in large numbers of sera is an enzyme immunoassay (EIA). To assess how EIA results would agree with those by the gold standard method of plaque reduction neutralization (PRN) we compared the results from the two methods in 43 pairs of maternal and umbilical cord sera, and sera from the corresponding infants when aged 11-14 months. In maternal-cord sera, the differences between mean antibody levels by EIA or PRN were not statistically significant, though in individual sera, differences could be large. However, agreement was less good for infants sera, in which levels of mIgG were very low. The conclusions of a study of transplacental transport of mIgG would not be affected by the use of either technique. When studying waning immunity in infants, PRN should be the method of choice, while results from studies using EIA should be interpreted with caution.

Calibration and use of an in-house anti-measles IgG standard serum

For the purpose of research a large quantity of anti-measles IgG working reference serum was needed. A pool of sera from five teenagers was prepared and named Alexandre Herculano (AH). In order to calibrate the AH serum, 18 EIA assays were performed testing in parallel AH and the 2nd International Standard 1990, Anti-Measles Antibody, 66/202 (IS) in a range of dilutions (from 1/50 to 1/25,600). A method which compared parallel lines resulting from the graphic representation of the results of laboratory tests was used to estimate the power of AH relative to IS. A computer programme written by one of the authors was used to analyze the data and make potency estimates. Another method of analysis was used, comparing logistic curves relating serum concentrations with optical density by EIA. For that purpose an existing computer programme (WRANL) was used. The potency of AH relative to IS, by either method, was estimated to be 2.4. As IS has 5000 milli international units (mIU) of anti-measles IgG per millilitre (ml), we concluded that AH has 12,000 mIU/ml.

[Anti-measles igg concentration in maternal blood and in umbilical cord blood: according to the mother's vaccination status]

A study on passive immunity against measles was conducted in four hospitals of Oporto, Portugal. The objectives were to assess whether maternal measles vaccination status was associated to the levels of measles IgG in maternal and cord sera, and with the transplacental transport efficiency. Cord and venous maternal blood samples were collected from 1539 mother-child pairs enrolled. An enzyme immunoassay was used to measure measles IgG levels in the study sera. Results were expressed in mIU/ml. Vaccination records were consulted. Geometric mean concentration of measles IgG among vaccinated mothers (730 mIU/ml; 95% CI 602 to 884 mIU/ml; n = 79) was significantly (P < 0.0001) lower than among their unvaccinated counterparts (1535 mIU/ml; 95% CI 1460 to 1613 mIU/ml; n = 1317). The same was observed in the corresponding cord sera: those born to vaccinated mothers had significantly (P < 0.0001) lower levels of measles IgG (1083 mIU/ml; 95% CI 908 to 1291) than the newborns of unvaccinated mothers (2230 mIU/ml; 95% CI 2119 to 2347). Transplacental transport efficiency was not related with maternal vaccination status (P = 0.67). Measles IgG levels observed in this Portuguese study were similar to those observed in a study conducted in South Africa, but higher than those reported in a British study. The differences in measles IgG levels between vaccinated and unvaccinated mothers (and corresponding newborns) are consistent with similar findings already published in different countries. The lower levels of measles IgG among children born to vaccinated mothers may lead to the anticipation of the recommended age to vaccinate against measles in Portugal.

Patterns of antimicrobial use and antimicrobial resistance among healthy children in Bolivia

OBJECTIVE

To determine the incidence of antimicrobial-resistant, nonpathogenic Escherichia coli among healthy children aged 6-72 months in Camiri town and a rural village, Javillo, in south-eastern Bolivia.

METHOD

A community-based survey: stool samples were obtained from 296 healthy children selected by modified cluster sampling in Camiri and all 25 eligible children in Javillo. E. coli isolates were tested for antimicrobial susceptibility according to the standard disc diffusion method. By a questionnaire survey of 12 pharmacies and by using simulated patients, we investigated the antimicrobial availability and the usage patterns in Camiri town.

RESULTS

In Camiri, over 90%, and in Javillo over 70% of children carried E. coli resistant to ampicillin, trimethoprim-sulphamethoxazole (TMP/SMX) or tetracycline. Overall, 63% of children carried E. coli with multiple resistance to ampicillin, TMP/SMX, tetracycline and chloramphenicol. In the simulated patients study, antimicrobials were dispensed inappropriately for 92% of adults and 40% of children with watery diarrhoea, and were under-prescribed for males with urethral discharge (67%) or females with fever and dysuria (58%). The dose and/or duration of antimicrobials dispensed was almost always too low.

CONCLUSION

Our study showed a disturbingly high prevalence of carriage of nonpathogenic E. coli resistant to antimicrobials. The prevalence of resistance to ampicillin and TMP/SMX was higher than that previously reported in developing countries. The existence of a large reservoir of resistance genes in healthy individuals in developing countries represents a threat to the success of antimicrobial therapy throughout the world. Programmes to improve rational and effective drug use in developing countries are urgently needed.

The use of mass campaigns in the expanded program on immunization: a review of reported advantages and disadvantages

The use of mass immunization campaigns (MICs) has been and remains controversial. To evaluate these campaigns, the authors review the literature relating to their effectiveness, sustainability, and cost-effectiveness in controlling diseases and raising immunization coverage levels, and their impact on the subsequent development of routine immunization services. Well-conducted campaigns have increased vaccine coverage levels and decreased disease morbidity and mortality. Their use in the Americas has been associated with the apparent elimination of poliomyelitis. However, unless health care infrastructure is improved, or campaigns are repeated, gains in coverage levels may not be sustained. Studies suggest that MICs are often not as cost-effective for raising coverage as the delivery of vaccines through routine services, but the use of coverage as the only outcome measure is questionable. Mass immunization campaigns can increase awareness of vaccination and may be appropriate in situations where new programs are to be initiated, in refugee situations where people congregate into areas with little infrastructure, and in disease eradication efforts when specific time goals are set. Little information is available on whether MICs strengthen or interfere with the development of routine services. To be successful, MICs require a well-coordinated and planned effort on the part of national authorities with the identification of specific goals, intensive social promotion, and strong management. In addition, research is needed to clarify how MICs should be evaluated.

Measles incidence, case fatality, and delayed mortality in children with or without vitamin A supplementation in rural Ghana

Data on measles incidence, acute case fatality, and delayed mortality were collected on 25,443 children aged 0-95 months during the course of a community-based, double-blind, placebo-controlled, randomized trial of vitamin A supplementation in rural, northern Ghana between 1989 and 1991. Measles vaccine coverage in these children was 48%. The overall estimated measles incidence rate was 24.3 per 1,000 child-years, and acute case fatality was 15.7%. There was not significantly increased mortality in survivors of the acute phase of measles compared with controls (rate ratio = 1.22, 95% confidence interval (CI) 0.65-2.30). Reported incidence rates and case fatality were higher in families with low paternal education, in the dry season, and in unvaccinated children, and case fatality was higher in malnourished children. There was no sex difference in incidence, but acute case fatality was somewhat higher in girls than boys (adjusted odds ratio = 1.3, 95% CI 0.9-2.1). Measles incidence was lower in vitamin A-supplemented groups (23.6 per 1,000 child-years) than in placebo groups (28.9 per 1,000 child-years), but this difference was not statistically significant (p = 0.33). Among 946 measles cases in clusters randomized to receive vitamin A or placebo, there was no marked difference in acute measles case fatality between vitamin A-supplemented and placebo groups (15.4% vs. 14.5%, respectively). The biologic effects of vitamin A supplemented on the subsequent clinical manifestations and severity of measles need further elucidation.

Ethical dilemmas in current planning for polio eradication

Intensification of polio eradication efforts worldwide raises concerns about costs and benefits for poor countries. A major argument for global funding is the high benefit-cost ratio of eradication; however, financial benefits are greatest for rich countries. By contrast, the greatest costs are borne by poor countries; the Pan American Health Organization has estimated that host countries bore 80% of costs for polio eradication in the Americas. The 1988 World Health Assembly resolution setting up the Polio Eradication Initiative carried the proviso that programs should strengthen health infrastructures. Drastic cuts in donor funding for health make this commitment even more important. Two international evaluations have reported both positive and negative effects of polio and Expanded Programme on Immunization programs on the functioning and sustainability of primary health care. Negative effects were greatest in poor countries with many other diseases of public health importance. If poor countries are expected to divert funds from their own urgent priorities, donors should make solid commitments to long-term support for sustainable health development.

Maternal and child health indicators in a rural South African health district

OBJECTIVE

To measure important maternal and child health indicators in a rural health district as part of the process of developing a comprehensive district health information system.

DESIGN

A modified Expanded Programme on Immunisation cluster sample survey.

SETTING

Hlabisa health district, KwaZulu-Natal.

PARTICIPANTS

480 mothers (or carers) of children aged 12-35 months surveyed in 32 clusters.

INTERVENTIONS

A questionnaire was administered and Road-to-Health cards were examined.

MAIN OUTCOME MEASURES

Proportion of women receiving antenatal care and delivering in a health facility; knowledge and understanding of vaccination; and recall of vaccination history. Proportion of children with a Road-to-Health card, overall coverage of each vaccine, coverage at 12 months of age and proportion receiving an immunogenic dose.

RESULTS

Most mothers (91%) had attended antenatal care, 77% had received tetanus toxoid and 83% delivered in a health facility. Only 14 children (3%) had never received a Road-to-Health card and 73% had one available at the time of the survey. Overall immunisation coverage was high (80-98%), as was the proportion receiving an immunogenic dose of each vaccine (78-98%). However, only 76% had received all the vaccines due to a 12-month-old child, and only 88% of these had received all doses by 12 months of age.

CONCLUSIONS

While the key maternal health indicators measured here are reassuring, there is still room for improvement in the child health indicators. The proportion of women receiving antenatal care and delivering in a health facility is very high, but the proportion of children receiving all vaccines can be improved upon, as can the timing of immunisation. The results of this survey are being used to strengthen further the primary health care services in the district.

Measles immunity and response to revaccination among secondary school children in Cumbria

The prevalence of antibody to measles virus in 759 children aged 11-18 years attending a secondary school in Cumbria was measured using a salivary IgG antibody capture assay. Serum IgG antibody levels were measured using a plaque reduction neutralization assay in subjects whose saliva was antibody negative. Vaccination histories were obtained from the child health computer and general practice record. A total of 662 pupils (87% of those tested) had detectable measles-specific IgG in saliva. Of the remaining 97, 82 provided blood samples and 29 had serum neutralizing antibody levels above 200 mIU/ml. Afer adjusting for non-participation rates, the proportion considered non-immune (no IgG in saliva and < or = 200 mIU/ml in serum) was 9% overall, ranging from 6% in vaccinated children to 20% in unvaccinated children. Measles-mumps-rubella vaccine was given to 50 children of whom 38 provided post-vaccination serum and 32 saliva samples. Thirty (79%) had a fourfold or greater rise in serum neutralizing antibody and 28 (88%) developed IgG antibody in saliva. Half of the children considered non-immune by antibody testing would have been overlooked in a selective vaccination programme targeted at those without a history of prior vaccination. A programme targeted at all school children should substantially reduce the proportion non-immune since a primary or booster response was achieved in three quarters of previously vaccinated children with low antibody levels and in all unvaccinated children. While it is feasible to screen a school-sized population for immunity to measles relatively quickly using a salivary IgG assay, a simple inexpensive field assay would need to be developed before salivary screening and selective vaccination could substitute for universal vaccination of populations at risk of measles outbreaks. The salivary IgG assay provided a sensitive measure of a booster response to vaccination.

The effect of stay in a maternity waiting home on perinatal mortality in rural Zimbabwe

A hospital-based cohort study was carried out in a district hospital in Zimbabwe to evaluate the effect of a maternity waiting home on perinatal mortality. Information on antenatal risk factors, use of antenatal care, access to the hospital and stage of labour on arrival was collected for each woman delivering at the hospital during the period 1989-1991 (n = 6438). Women who stayed in the maternity waiting home had a lower risk of perinatal death compared to women who came directly from home to the hospital during labour. The crude relative risk of perinatal death for the women coming from home was 1.7 (95% confidence interval (CI) 1.1-2.6; P < 0.05). After adjusting for the effect of potential confounding variables, the relative risk decreased to 1.5 (95% CI 0.95-2.5, P = 0.07). However, when the analysis was restricted to women with antenatal risk factors there was a significant 50% reduction in the risk of perinatal death for the women who stayed at the maternity waiting home compared to women who came from home during labour (adjusted relative risk 1.9; 95% CI 1.1-3.4; P < 0.05). The use of maternity waiting homes has the potential to reduce perinatal mortality in rural areas with low geographic access to hospitals and merits further evaluation.

Effects of a maternity waiting home on adverse maternal outcomes and the validity of antenatal risk screening

OBJECTIVES

To evaluate the effect of a maternity waiting home (MWH) on adverse maternal outcomes and the validity of antenatal risk criteria in predicting dystocia.

METHOD

A hospital-based cohort study was conducted at a district hospital in Zimbabwe. Information on the presence of antenatal risk factors, stay at an MWH, and mode and outcome of delivery was collected for each woman delivering at the hospital during 1989-1991.

RESULTS

The risk of obstructed labor was 16 times higher for those not attending an MWH (n = 2915) than for those who did attend an MWH (n = 1573) (1 vs. 0.06%, P < 0.005). Among the non-users, 0.3% suffered a ruptured uterus compared with none of the MWH users. The presence of any one of the antenatal risk criteria used in Zimbabwe had a sensitivity of 78%, a specificity of 51% and positive predictive value of 25% for predicting dystocia.

CONCLUSION

MWHs and antenatal risk screening are policy options for safe motherhood programs in settings where emergency obstetric services are not easily accessible.

Obsessive-compulsive disorder: prediction of outcome from behavioural psychotherapy

Prediction of outcome after behavioural psychotherapy was determined in 178 outpatients with obsessive-compulsive disorder. For women (n = 103), factors significantly associated with good outcome included paid employment at time of assessment, having a co-therapist and low initial ratings on global phobia, work and home activity impairment and the compulsion checklist. In men, the only factor to approach statistical significance as a predictor of outcome was solitary abode, associated with "less improved" status.