Identifying high-risk areas for sporadic measles outbreaks: lessons from South Africa

Dimeric immunoglobulin A as a novel diagnostic marker of measles infection

IMPORTANCE

The world is facing a measles resurgence, and improved diagnostic tests for measles infection are an urgent World Health Organization research priority. Detection of measles-specific immunoglobulin M (IgM) as a standard diagnostic test has low positive predictive value in elimination settings, and there is a need for new biomarkers of measles infection to enable enhanced surveillance and response to outbreaks. We demonstrate the detection of measles-specific dimeric immunoglobulin A (dIgA) in patients with confirmed measles infections using a new indirect enzyme-linked immunosorbent assay protocol that selects for the dIgA fraction from total IgA in the blood. The magnitude of measles-specific dIgA responses showed a low correlation with IgM responses, and our results highlight the potential of dIgA for further development as an alternative and/or complementary biomarker to IgM for serological diagnosis of measles infection.

Spatial variations in STIs among women enrolled in HIV prevention clinical trials in Durban, KwaZulu-Natal, South Africa

South Africa is faced with a high HIV and STI prevalence and incidence, respectively, with pockets of high burden areas driving these diseases. Localised monitoring of the HIV epidemic and STI endemic would enable more effective targeted prevention strategies. We assessed spatial variations in curable STI incidence among a cohort of women enrolled in HIV prevention clinical trials between 2002 and 2012. STI incidence rates from 7557 South African women enrolled in five HIV prevention trials were geo-mapped using participant household GPS coordinates. Age and period standardised incidence rates were calculated for 43 recruitment areas and Bayesian conditional autoregressive areal spatial regression (CAR) was used to identify significant patterns and spatial patterns of STI infections in recruitment communities. Overall age and period standardised STI incidence rate were estimated as 15 per 100 PY and ranged from 6 to 24 per 100 PY. We identified five significant STI high risk areas with higher-than-expected incidence of STIs located centrally (three-locations) and southern neighbouring areas of Durban (two-locations). Younger age (<25), not married/cohabitating, parity <3 and poor education were all significant correlates of high STI communities. Findings demonstrate sustained STI incidence rates across the greater Durban area. The role of STI incidence in HIV acquisition in high HIV endemic areas need to be revisited as current highly effective PrEP interventions do not protect from STI acquisition. In these settings there is an urgent need for integrative HIV and STI prevention and treatment services.

Measuring Multiple Dimensions and Indices of Nonvaccination Clustering in Michigan, 2008-2018

Michigan experienced a significant measles outbreak in 2019 amidst rising rates of nonmedical vaccine exemptions (NMEs) and low vaccination coverage compared with the rest of the United States. There is a critical need to better understand the landscape of nonvaccination in Michigan to assess the risk of vaccine-preventable disease outbreaks in the state, yet there is no agreed-upon best practice for characterizing spatial clustering of nonvaccination, and numerous clustering metrics are available in the statistical, geographical, and epidemiologic literature. We used school-level data to characterize the spatiotemporal landscape of vaccine exemptions in Michigan for the period 2008-2018 using Moran's I, the isolation index, the modified aggregation index, and the Theil index at 4 spatial scales. We also used nonvaccination thresholds of 5%, 10%, and 20% to assess the bias incurred when aggregating vaccination data. We found that aggregating school-level data to levels commonly used for public reporting can lead to large biases in identifying the number and location of at-risk students and that different clustering metrics yielded variable interpretations of the nonvaccination landscape in Michigan. This study shows the importance of choosing clustering metrics with their mechanistic interpretations in mind, be it large- or fine-scale heterogeneity or between- and within-group contributions to spatial variation.

Vaccine Delay and Its Association With Undervaccination in Children in Sub-Saharan Africa

INTRODUCTION

Improving the timeliness and completion of vaccination is the key to reducing under-5 childhood mortality. This study examines the prevalence of delayed vaccination for doses administered at birth and age 6 weeks, 10 weeks, 14 weeks, and 9 months and its association with undervaccination among infants in Sub-Saharan Africa.

METHODS

Pooling data across 33 Sub-Saharan Africa countries, vaccination timing and series completion were assessed for children aged 12-35 months who were included in the immunization module of the Demographic and Health Surveys conducted between 2010 and 2019. Survey design-adjusted logistic regression modeled the likelihood of not fully completing the basic immunization schedule associated with dose-specific delays in vaccination. Data were obtained and analyzed in May 2020.

RESULTS

Among children with complete date records (n=70,006), the proportion of children vaccinated with delays by ≥1 month was high: 25.9% for Bacille Calmette-Guerin (at birth); 49.1% for the third dose of pentavalent combination vaccine (at 14 weeks); and 63.9% for the first dose of measles vaccines (at 9 months). Late vaccination was more common for children born to mothers with lower levels of educational attainment (p<0.001) and wealth (p<0.001). Controlling for place, time, and sociodemographics, vaccination delays at any dose were significantly associated with not completing the immunization schedule by 12 months (Bacille Calmette-Guerin: AOR=1.93, [95% CI=1.83, 2.02]; pentavalent 3: AOR=1.50 [95% CI=1.35, 1.64]; measles: AOR=3.76 [95% CI=3.37, 4.15]).

CONCLUSIONS

Timely initiation of vaccination could contribute to higher rates of immunization schedule completion, improving the reach and impact of vaccination programs on child health outcomes in Sub-Saharan Africa.

SUPPLEMENT INFORMATION

This article is part of a supplement entitled Global Vaccination Equity, which is sponsored by the Global Institute for Vaccine Equity at the University of Michigan School of Public Health.

Fine-scale spatial clustering of measles nonvaccination that increases outbreak potential is obscured by aggregated reporting data

The United States experienced historically high numbers of measles cases in 2019, despite achieving national measles vaccination rates above the World Health Organization recommendation of 95% coverage with two doses. Since the COVID-19 pandemic began, resulting in suspension of many clinical preventive services, pediatric vaccination rates in the United States have fallen precipitously, dramatically increasing risk of measles resurgence. Previous research has shown that measles outbreaks in high-coverage contexts are driven by spatial clustering of nonvaccination, which decreases local immunity below the herd immunity threshold. However, little is known about how to best conduct surveillance and target interventions to detect and address these high-risk areas, and most vaccination data are reported at the state-level-a resolution too coarse to detect community-level clustering of nonvaccination characteristic of recent outbreaks. In this paper, we perform a series of computational experiments to assess the impact of clustered nonvaccination on outbreak potential and magnitude of bias in predicting disease risk posed by measuring vaccination rates at coarse spatial scales. We find that, when nonvaccination is locally clustered, reporting aggregate data at the state- or county-level can result in substantial underestimates of outbreak risk. The COVID-19 pandemic has shone a bright light on the weaknesses in US infectious disease surveillance and a broader gap in our understanding of how to best use detailed spatial data to interrupt and control infectious disease transmission. Our research clearly outlines that finer-scale vaccination data should be collected to prevent a return to endemic measles transmission in the United States.

Using routine health information data for research in low- and middle-income countries: a systematic review

BACKGROUND

Routine health information systems (RHISs) support resource allocation and management decisions at all levels of the health system, as well as strategy development and policy-making in many low- and middle-income countries (LMICs). Although RHIS data represent a rich source of information, such data are currently underused for research purposes, largely due to concerns over data quality. Given that substantial investments have been made in strengthening RHISs in LMICs in recent years, and that there is a growing demand for more real-time data from researchers, this systematic review builds upon the existing literature to summarize the extent to which RHIS data have been used in peer-reviewed research publications.

METHODS

Using terms 'routine health information system', 'health information system', or 'health management information system' and a list of LMICs, four electronic peer-review literature databases were searched from inception to February 202,019: PubMed, Scopus, EMBASE, and EconLit. Articles were assessed for inclusion based on pre-determined eligibility criteria and study characteristics were extracted from included articles using a piloted data extraction form.

RESULTS

We identified 132 studies that met our inclusion criteria, originating in 37 different countries. Overall, the majority of the studies identified were from Sub-Saharan Africa and were published within the last 5 years. Malaria and maternal health were the most commonly studied health conditions, although a number of other health conditions and health services were also explored.

CONCLUSIONS

Our study identified an increasing use of RHIS data for research purposes, with many studies applying rigorous study designs and analytic methods to advance program evaluation, monitoring and assessing services, and epidemiological studies in LMICs. RHIS data represent an underused source of data and should be made more available and further embraced by the research community in LMIC health systems.

Factors Associated With Measles Transmission in the United States During the Postelimination Era

IMPORTANCE

Measles cases and outbreaks continue to occur in the United States after the introduction of measles from endemic settings.

OBJECTIVE

To discern the factors associated with measles transmission in the United States after measles had been eliminated.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study was conducted from January 1, 2001, to December 31, 2017, in the United States among US residents and international visitors with confirmed measles. A maximum likelihood algorithm that uses the observed dates of rash onset and the known distribution of the serial interval (time between symptom onset in related consecutive cases) was applied to outbreak notification data to estimate the effective reproduction number (R), or the mean number of new infections generated per case. Transmissibility was assessed by comparing R based on the characteristics of primary and secondary cases of measles.

EXPOSURES

Measles virus.

MAIN OUTCOMES AND MEASURES

Effective reproduction number (R), or the mean number of successful transmission events per case of measles (ie, the mean number of persons to whom each patient with measles spreads measles).

RESULTS

A total of 2218 individuals with confirmed measles cases (1025 female, 1176 male, and 17 sex not reported; median age, 15 years [range, 0-89 years]) reported from 2001 to 2017 were evaluated. Among patients who received no doses of measles vaccine, R was 0.76 (95% CI, 0.71-0.81); among patients who received 1 dose of measles vaccine, R was 0.17 (95% CI, 0.11-0.26); among patients who received 2 doses or more of measles vaccine, R was 0.27 (95% CI, 0.17-0.39); and among patients with unknown vaccination status, R was 0.52 (95% CI, 0.44-0.60). Among patients born before 1957, R was 0.35 (95% CI, 0.20-0.58), and among those born on or after 1957, R was 0.64 (95% CI, 0.61-0.68). R was higher when primary and secondary cases of measles were patients aged 5 to 17 years (0.36 [95% CI, 0.31-0.42]) compared with assortative transmission in other age groups (<1 year, 0.14 [95% CI, 0.10-0.20]; 1-4 years, 0.25 [95% CI, 0.20-0.30]; 18-29 years, 0.19 [95% CI, 0.15-0.24]; 30-49 years, 0.15 [95% CI, 0.11-0.20]; ≥50 years, 0.04 [95% CI, 0.01-0.10]).

CONCLUSIONS AND RELEVANCE

The findings of this study support having high targets for 2-dose measles vaccine coverage, particularly among school-aged children in the United States.

Measles in Zhejiang, China, 2004-2017: Population Density and Proportion of Floating Populations Effects on Measles Epidemic

The target of eliminating measles has not been achieved, and measles has resurged in Zhejiang, China, since 2013. In this study, we hypothesized that population density and the proportion of the floating population were the potential causes of measles persistence in Zhejiang. Measles cases in Zhejiang from 2004 through 2017 were analyzed using data from the National Notifiable Diseases Reporting System (NNDRS). Reported measles incidence and annual incidence by age were described. Spearman correlation coefficients were used to assess correlations between measles incidence and population density and the proportion of floating population. A total of 48,648 measles cases were reported during the 14-year period. Two large measles epidemics occurred in 2005 (14,317 cases, incidence of 29.38/100,000) and 2008 (12,782 cases, incidence of 25.26/100,000). A higher proportion of cases occurred in young adults aged 20 to 34 years and infants under 1 year of age. A positive correlation was observed between measles incidence and either population density or proportion of inter-provincial floating populations. In general, Zhejiang suffers from a high incidence of measles partly because of its high population density and the low vaccination rates among inter-provincial floating populations. To meet the target of measles elimination, convincing susceptible young adults and migrant children to get vaccinated remains a critical issue.

Risk Factors for Infectious Diseases in Urban Environments of Sub-Saharan Africa: A Systematic Review and Critical Appraisal of Evidence

Our world is rapidly urbanizing. According to the United Nations, between 1990 and 2015, the percent of the world's population living in urban areas grew from 43% to 54%. Estimates suggest that this trend will continue and that over 68% of the world's population will call cities home by 2050, with the majority of urbanization occurring in African countries. This urbanization is already having a profound effect on global health and could significantly impact the epidemiology of infectious diseases. A better understanding of infectious disease risk factors specific to urban settings is needed to plan for and mitigate against future urban outbreaks. We conducted a systematic literature review of the Web of Science and PubMed databases to assess the risk factors for infectious diseases in the urban environments of sub-Saharan Africa. A search combining keywords associated with cities, migration, African countries, infectious disease, and risk were used to identify relevant studies. Original research and meta-analyses published between 2004 and 2019 investigating geographical and behavioral risk factors, changing disease distributions, or control programs were included in the study. The search yielded 3610 papers, and 106 met the criteria for inclusion in the analysis. Papers were categorized according to risk factors, geographic area, and study type. The papers covered 31 countries in sub-Saharan Africa with East Africa being the most represented sub-region. Malaria and HIV were the most frequent disease focuses of the studies. The results of this work can inform public health policy as it relates to capacity building and health systems strengthening in rapidly urbanizing areas, as well as highlight knowledge gaps that warrant additional research.

Measles Immunity at 4.5 Years of Age Following Vaccination at 9 and 15-18 Months of Age Among Human Immunodeficiency Virus (HIV)-infected, HIV-exposed-uninfected, and HIV-unexposed Children

BACKGROUND

Human immunodeficiency virus (HIV)-infected and HIV-exposed-uninfected (HEU) children may be at increased risk of measles infection due to waning of immunity following vaccination. We evaluated persistence of antibodies to measles vaccination at 4.5 years of age in HIV-unexposed, HEU, and HIV-infected children with CD4+ ≥25% previously randomized to immediate antiretroviral therapy (ART) interrupted at 12 months (HIV/Immed-ART-12), 24 months (HIV/Immed-ART-24), or when clinically/immunologically indicated (HIV/Def-ART). The HIV/Def-ART group initiated ART by median 5.8 (interquartile range, 4.4-10.3) months of age.

METHODS

In this study, HIV-unexposed (n = 95), HEU (n = 84), HIV/Immed-ART-12 (n = 70), HIV/Immed-ART-24 (n = 70), and HIV/Def-ART (n = 62) children were scheduled to receive measles vaccination at age 9 and 15-18 months. Antimeasles serum immunoglobulin G titers were quantified using enzyme-linked immunosorbent assay at 4.5 years.

RESULTS

Compared with HIV-unexposed children (2860 mIU/mL), measles antibody geometric mean titers (GMTs) were significantly lower in both HIV/Immed-ART-12 (571; P < .001) and HIV/Immed-ART-24 (1136; P < .001) but similar in the HIV/Def-ART (2777) and HEU (3242) groups. Furthermore, compared with HIV-unexposed, antibody titers ≥330 mIU/mL (ie, presumed serocorrelate for protection; 99%) were also significantly lower in HIV/Immed-ART-12 (70%; P < .001) and HIV/Immed-ART-24 (83%; P < .001) but similar in the HIV/Def-ART (90%) and HEU (98%) groups.

CONCLUSIONS

HIV-infected children in whom ART was interrupted at either 12 or 24 months had lower GMTs and lower proportions with seroprotective titers than HIV-unexposed children, indicating a potential downside of ART treatment interruption.

CLINICAL TRIALS REGISTRATION

NCT00099658 and NCT00102960.

Measles outbreak risk in Pakistan: exploring the potential of combining vaccination coverage and incidence data with novel data-streams to strengthen control

Although measles incidence has reached historic lows in many parts of the world, the disease still causes substantial morbidity globally. Even where control programs have succeeded in driving measles locally extinct, unless vaccination coverage is maintained at extremely high levels, susceptible numbers may increase sufficiently to spark large outbreaks. Human mobility will drive potentially infectious contacts and interact with the landscape of susceptibility to determine the pattern of measles outbreaks. These interactions have proved difficult to characterise empirically. We explore the degree to which new sources of data combined with existing public health data can be used to evaluate the landscape of immunity and the role of spatial movement for measles introductions by retrospectively evaluating our ability to predict measles outbreaks in vaccinated populations. Using inferred spatial patterns of accumulation of susceptible individuals and travel data, we predicted the timing of epidemics in each district of Pakistan during a large measles outbreak in 2012–2013 with over 30 000 reported cases. We combined these data with mobility data extracted from over 40 million mobile phone subscribers during the same time frame in the country to quantify the role of connectivity in the spread of measles. We investigate how different approaches could contribute to targeting vaccination efforts to reach districts before outbreaks started. While some prediction was possible, accuracy was low and we discuss key uncertainties linked to existing data streams that impede such inference and detail what data might be necessary to robustly infer timing of epidemics.

Spatial clustering of measles vaccination coverage among children in sub-Saharan Africa

Background

During the past two decades, vaccination programs have greatly reduced global morbidity and mortality due to measles, but recently this progress has stalled. Even in countries that report high vaccination coverage rates, transmission has continued, particularly in spatially clustered subpopulations with low vaccination coverage.

Methods

We examined the spatial heterogeneity of measles vaccination coverage among children aged 12–23 months in ten Sub-Saharan African countries. We used the Anselin Local Moran’s I to estimate clustering of vaccination coverage based on data from Demographic and Health Surveys conducted between 2008 and 2013. We also examined the role of sociodemographic factors to explain clustering of low vaccination.

Results

We detected 477 spatial clusters with low vaccination coverage, many of which were located in countries with relatively high nationwide vaccination coverage rates such as Zambia and Malawi. We also found clusters in border areas with transient populations. Clustering of low vaccination coverage was related to low health education and limited access to healthcare.

Conclusions

Systematically monitoring clustered populations with low vaccination coverage can inform supplemental immunization activities and strengthen elimination programs. Metrics of spatial heterogeneity should be used routinely to determine the success of immunization programs and the risk of disease persistence.

Zinc supplementation for the treatment of measles in children

BACKGROUND

Measles is an important cause of childhood morbidity and mortality globally, despite increasing vaccine coverage. Zinc plays a significant role in the maintenance of normal immunological functions, therefore supplements given to zinc-deficient children will increase the availability of zinc and could reduce measles-related morbidity and mortality. This is an update of a review first published in 2015.

OBJECTIVES

To assess the effects of zinc supplementation in reducing morbidity and mortality in children with measles.

SEARCH METHODS

We searched CENTRAL (03 February 2017, Issue 2), MEDLINE (1946 to 03 February 2017), Embase (1974 to 03 February 2017), CINAHL (1981 to 03 February 2017), LILACS (1982 to 03 February 2017), Web of Science (1985 to 03 February 2017), and BIOSIS Previews (1985 to 27 June 2014). We also searched ClinicalTrials.gov, the Australian New Zealand Clinical Trials Registry and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) on 03 February 2017 to identify unpublished and ongoing studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of zinc in reducing morbidity and mortality in children with measles.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the studies for inclusion and extracted data on outcomes, details of the interventions, and other study characteristics using a standardised data extraction form. We used risk ratio (RR) and hazard ratio (HR) as measures of effect with 95% confidence intervals (CI). We included only one study, and did not conduct meta-analysis.

MAIN RESULTS

We did not identify any new studies for inclusion in this update. One RCT met our inclusion criteria. The study was conducted in India and included 85 children diagnosed with measles and pneumonia. The trial showed no significant difference in mortality between children with measles and pneumonia who received zinc supplements and those who received placebo (RR 0.34, 95% CI 0.01 to 8.14). There was no significant difference in time to absence of fever between children who received zinc supplements and those who did not (HR 1.08, 95% CI 0.67 to 1.74). No treatment-related side effects were reported in either group. We assessed the overall quality of the evidence as very low.

AUTHORS' CONCLUSIONS

We could not draw any definitive conclusions from this review about the effects of zinc supplementation on clinical outcomes of children with measles due to the very low quality of the evidence available. There is insufficient evidence to confirm or refute the effect of zinc supplementation in children with measles.

Development of a District-Level Programmatic Assessment Tool for Risk of Measles Virus Transmission

All six World Health Organization (WHO) regions have now set goals for measles elimination by or before 2020. To prioritize measles elimination efforts and use available resources efficiently, there is a need to identify at-risk areas that are offtrack from meeting performance targets and require strengthening of programmatic efforts. This article describes the development of a WHO measles programmatic risk assessment tool to be used for monitoring, guiding, and sustaining measles elimination efforts at the subnational level. We outline the tool development process; the tool specifications and requirements for data inputs; the framework of risk categories, indicators, and scoring; and the risk category assignment. Overall risk was assessed as a function of indicator scores that fall into four main categories: population immunity, surveillance quality, program performance, and threat assessment. On the basis of the overall score, the tool assigns each district a risk of either low, medium, high, or very high. The cut-off criteria for the risk assignment categories were based on the distribution of scores from all possible combinations of individual indicator cutoffs. The results may be used for advocacy to communicate risk to policymakers, mobilize resources for corrective actions, manage population immunity, and prioritize programmatic activities. Ongoing evaluation of indicators will be needed to evaluate programmatic performance and plan risk mitigation activities effectively. The availability of a comprehensive tool that can identify at-risk districts will enhance efforts to prioritize resources and implement strategies for achieving the Global Vaccine Action Plan goals for measles elimination.

Measles immunity among pregnant women aged 15-44 years in Namibia, 2008 and 2010

Background:

Namibia experienced a large measles outbreak starting in 2009, with 38% of reported cases in adults, including women of reproductive age. Population immunity was assessed among pregnant women to determine whether immunization activities were needed in adults to achieve measles elimination in Namibia.

Methods:

A total of 1708 and 2040 specimens sampled from Namibian pregnant women aged 15–44 years who were included in the 2008 and 2010 National HIV Sentinel Survey, respectively, were tested for measles immunoglobulin G antibody. The proportion of women seropositive overall and by 5-year age strata was determined, and factors associated with seropositivity were analyzed by logistic regression, including age, facility type, gravidity, HIV status, and urban/rural setting. Seropositivity in 2008 versus 2010 was compared.

Results:

In both analysis years, measles seropositivity was lower in 15–19-year-olds (77%) and 20–24-year-olds (85–87%) and higher in 25–44-year-olds (90–94%) (2008, p < 0.001; 2010, p < 0.001). Overall measles seropositivity did not differ between 2008 (87%) and 2010 (87%) (p = 0.7). HIV status did not affect seropositivity.

Conclusions:

Late in a large measles outbreak, 13% of pregnant women in Namibia, and almost one in four 15–19-year-old pregnant women, remained susceptible to measles. In Namibia, immunization campaigns with measles-containing vaccine should be considered for adults.

Impact of population size on incidence of rubella and measles in comparison with that of other infectious diseases

A strong dependency of rubella and measles epidemics on population size was confirmed by 2 types of plots: the cumulative frequency distribution of number of cases per prefecture and the slope of the log-log plots of number of cases per prefecture on the y-axis vs. prefecture population size on the x-axis. These parameters were found to be constant and unique to each infectious agent. The broader cumulative frequency distribution and steeper slope of the log-log plots were characteristic to measles and rubella, i.e., a higher population size was correlated with a disproportionate high incidence of measles and rubella. No such tendency was found in other infections with possible exceptions of pertussis and keratoconjunctivitis. The dependency of rubella and measles on population density was examined by log-log plots of patient number/population vs. population density, which revealed strong population density dependency of rubella; the dependency of measles on population density was equivocal.

Zinc supplementation for the treatment of measles in children

BACKGROUND

Measles is still an important cause of childhood morbidity and mortality globally, despite increasing vaccine coverage. Zinc plays a significant role in the maintenance of normal immunological functions, therefore supplements given to zinc-deficient children will increase the availability of zinc and could reduce measles-related morbidity and mortality.

OBJECTIVES

To assess the effects of zinc supplementation in reducing morbidity and mortality in children with measles.

SEARCH METHODS

We searched CENTRAL (2014, Issue 5), MEDLINE (1946 to June week 3, 2014), EMBASE (1974 to June 2014), CINAHL (1981 to June 2014), LILACS (1982 to June 2014), Web of Science (1985 to June 2014) and BIOSIS Previews (1985 to June 2014). We also searched ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) to identify unpublished and ongoing studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of zinc in reducing morbidity and mortality in children with measles.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the studies for inclusion and extracted data on outcomes, details of the interventions and other study characteristics using a standardised data extraction form. We used the risk ratio (RR) and hazard ratio as measures of effect with 95% confidence intervals (CI). We included only one study and we did not conduct any meta-analysis.

MAIN RESULTS

One RCT met our inclusion criteria. The study was conducted in India and included 85 children diagnosed with measles and pneumonia. The trial showed that there was no significant difference in mortality between the two groups (risk ratio (RR) 0.34, 95% confidence interval (CI) 0.01 to 8.14). Also, there was no significant difference in time to absence of fever between the two groups (hazard ratio (HR) 1.08, 95% CI 0.67 to 1.74). No treatment-related side effects were reported in either group. The overall quality of the evidence can be described as very low.

AUTHORS' CONCLUSIONS

We cannot draw any definite conclusions from this review about the effects of zinc supplementation on clinical outcomes of children with measles due to the very low quality of the evidence available. There is insufficient evidence to confirm or refute the effect of zinc supplementation in measles.

Spatial clustering of measles cases during endemic (1998-2002) and epidemic (2010) periods in Lusaka, Zambia

BACKGROUND

Measles cases may cluster in densely populated urban centers in sub-Saharan Africa as susceptible individuals share spatially dependent risk factors and may cluster among human immunodeficiency virus (HIV)-infected children despite high vaccination coverage.

METHODS

Children hospitalized with measles at the University Teaching Hospital (UTH) in Lusaka, Zambia were enrolled in the study. The township of residence was recorded on the questionnaire and mapped; SaTScan software was used for cluster detection. A spatial-temporal scan statistic was used to investigate clustering of measles in children hospitalized during an endemic period (1998 to 2002) and during the 2010 measles outbreak in Lusaka, Zambia.

RESULTS

Three sequential and spatially contiguous clusters of measles cases were identified during the 2010 outbreak but no clustering among HIV-infected children was identified. In contrast, a space-time cluster among HIV-infected children was identified during the endemic period. This cluster occurred prior to the introduction of intensive measles control efforts and during a period between seasonal peaks in measles incidence.

CONCLUSIONS

Prediction and early identification of spatial clusters of measles will be critical to achieving measles elimination. HIV infection may contribute to spatial clustering of measles cases in some epidemiological settings.

Transport networks and inequities in vaccination: remoteness shapes measles vaccine coverage and prospects for elimination across Africa

Measles vaccination is estimated to have averted 13·8 million deaths between 2000 and 2012. Persisting heterogeneity in coverage is a major contributor to continued measles mortality, and a barrier to measles elimination and introduction of rubella-containing vaccine. Our objective is to identify determinants of inequities in coverage, and how vaccine delivery must change to achieve elimination goals, which is a focus of the WHO Decade of Vaccines. We combined estimates of travel time to the nearest urban centre (⩾50 000 people) with vaccination data from Demographic Health Surveys to assess how remoteness affects coverage in 26 African countries. Building on a statistical mapping of coverage against age and geographical isolation, we quantified how modifying the rate and age range of vaccine delivery affects national coverage. Our scenario analysis considers increasing the rate of delivery of routine vaccination, increasing the target age range of routine vaccination, and enhanced delivery to remote areas. Geographical isolation plays a key role in defining vaccine inequity, with greater inequity in countries with lower measles vaccine coverage. Eliminating geographical inequities alone will not achieve thresholds for herd immunity, indicating that changes in delivery rate or age range of routine vaccination will be required. Measles vaccine coverage remains far below targets for herd immunity in many countries on the African continent and is likely to be inadequate for achieving rubella elimination. The impact of strategies such as increasing the upper age range eligible for routine vaccination should be considered.

Childhood immunisation in Bungoma County, Kenya, from 2008 to 2011: need for improved uptake

Uptake of immunisations in children aged 1-2 years in Bungoma County, Kenya, was determined as part of the 6-monthly Health and Demographic Surveillance System surveys. A total of 2699 children were assessed between 2008 and 2011. During this time period, full immunisation declined significantly from 84% to 58%, and measles vaccine declined uptake from 89% to 60% (P < 0.001). Each year there was a significant fall-off for the third doses of the oral polio and pentavalent vaccines (P < 0.001). These findings are of concern, as low immunisation coverage may lead to vaccine-preventable disease outbreaks. Further investigations into the reasons for declining immunisation trends are required.

Measles resurgence in southern Africa: challenges to measles elimination

INTRODUCTION

In seven southern African countries (Botswana, Lesotho, Malawi, Namibia, South Africa, Swaziland and Zimbabwe), following implementation of a measles mortality reduction strategy starting in 1996, the number of annually reported measles cases decreased sharply to less than one per million population during 2006-2008. However, during 2009-2010, large outbreaks occurred in these countries. In 2011, a goal for measles elimination by 2020 was set in the World Health Organization (WHO) African Region (AFR). We reviewed the implementation of the measles control strategy and measles epidemiology during the resurgence in the seven southern African countries.

METHODS

Estimated coverage with routine measles vaccination, supplemental immunization activities (SIA), annually reported measles cases by country, and measles surveillance and laboratory data were analyzed using descriptive analysis.

RESULTS

In the seven countries, coverage with the routine first dose of measles-containing vaccine (MCV1) decreased from 80% to 65% during 1996-2004, then increased to 84% in 2011; during 1996-2011, 79,696,523 people were reached with measles vaccination during 45 SIAs. Annually reported measles cases decreased from 61,160 cases to 60 cases and measles incidence decreased to <1 case per million during 1996-2008. During 2009-2010, large outbreaks that included cases among older children and adults were reported in all seven countries, starting in South Africa and Namibia in mid-2009 and in the other five countries by early 2010. The measles virus genotype detected was predominantly genotype B3.

CONCLUSION

The measles resurgence highlighted challenges to achieving measles elimination in AFR by 2020. To achieve this goal, high two-dose measles vaccine coverage by strengthening routine immunization systems and conducting timely SIAs targeting expanded age groups, potentially including young adults, and maintaining outbreak preparedness to rapidly respond to outbreaks will be needed.