Measles Virus Infection Among Vaccinated and Unvaccinated Children in Nigeria

Disease Progression, Clinical Features, and Risk Factors for Pneumonia in Unvaccinated Children and Adolescents with Measles: A Re-Emerging Disease in Romania

Measles causes in vaccinated children, with some exceptions, a mild disease, while the unvaccinated can suffer complications that result in serious consequences and even death. Although the introduction of the measles vaccine has reduced the number of cases and the viral spread, the current downward vaccination trend has resulted in the resurgence of the disease. Currently, Romania has a measles vaccination coverage below the 95% safety threshold. Thus, an outbreak started in 2016 and still ongoing in Romania, many cases being identified in the Western region in the pediatric population. Our objective was to conduct a thorough examination of clinical characteristics, evolution, and risk factors in vaccinated and unvaccinated children in this region. To reach our objectives we used a retrospective cohort analysis. The authors reviewed clinical and laboratory data from patients hospitalized at "Victor Babes" Hospital for Infectious Diseases and Pulmonology in Timisoara. We found a total of 136 qualifying cases of measles among the children admitted to this facility. The two comparison groups consisted of 104 children under 10 years and 32 patients between 10 and 18 years. An important characteristic of both study groups was the high prevalence of patients from the Roma ethnicity, which, although represents a minority in Romania, the prevalence was over 40% in the current study. The infection source was in 40.4% of children under 10 years inside the family, while 71.9% of infections in the group of adolescents were isolated (p-value = 0.047). The multivariate risk factor analysis identified as independent risk factors for the development of pneumonia the older age of patients (OR = 1.62), poor nutritional status (OR = 1.25), Roma ethnicity (OR = 2.44), presence of anemia (OR = 1.58), and procalcitonin (OR = 3.09). It is essential to handle these risk factors in a patient with measles, especially in conjunction with an unknown vaccination status. To achieve a vaccination rate greater than 95 percent for Romanian children, measles vaccination awareness must be promoted, moreover in the Roma population. More comprehensive preventative methods must be developed promptly with the objective of eradicating measles in Romania via a vigorous vaccination campaign.

Measles-Rubella Positivity Rate and Associated Factors in Pre-Mass and Post-Mass Vaccination Periods: Analysis of Uganda Routine Surveillance Laboratory Data

Toward 2019, Uganda experienced an extensive outbreak of measles and rubella. The Uganda National Expanded Programme on Immunization implemented a mass measles-rubella vaccination campaign aimed at halting the ongoing transmission. This study determined the changes in the disease burden thereafter. We conducted a retrospective cross-sectional study on measles-rubella positivity and its associated factors in Uganda using 1697 case-based surveillance data for 2019 and 2020 stratified into two dispensations: prevaccination and postvaccination campaigns. Statistical tests employed in STATA 15 included chi-square, Fisher’s exact, and binomial tests. Measles positivity rates in the period before and after the mass immunization campaign were 41.88% (95% CI: 39.30–44.51) and 37.96% (95% CI: 32.81–43.40), respectively. For rubella, the positivity rate in the precampaign season was 21.73% (95% CI: 19.61–23.99) and in the postvaccination season was 6.65% (95% CI: 4.36–10.00). Binomial tests indicated that postcampaign positivity rates were significantly lower than the precampaign rate for measles ( $p=0.003$ ) and rubella ( $p<0.001$ ). Generally, age (χ2 = 58.94, $p=0.001$ /χ2 = 51.91, $p<0.001$ ) and vaccination status (χ2 = 60.48, $p=0.001$ /χ2 = 16.90, $p=0.001$ ) were associated with the measles positivity rate in both pre/postcampaign periods. Rubella positivity rate was associated with vaccination status (χ2 = 32.97, $p<0.001$ / $p=0.001$ ) in both periods and age in the precampaign season ( $p<0.001$ ). The measles-rubella mass campaign lessened rubella burden remarkably, but barely adequate change was observed in the extent of spread of measles. Children aged less than 9 months are at higher chances of testing positive amidst low vaccination levels among the eligible. The immunization programme must attain and maintain routine immunization coverage at 95% or more and roll out a second-dose measles-rubella vaccination to sustain the reduced disease burden.

Effectiveness of "Priorix" Against Measles and Mumps Diseases in Children Born After 2004 in the United Kingdom: A Retrospective Case-control Study Using the Clinical Practice Research Datalink GOLD Database

BACKGROUND

Evidence on vaccine effectiveness (VE) may encourage vaccination and help fight the reemergence of measles and mumps in Europe. However, limited data exist on real-life effectiveness of individual measles, mumps and rubella (MMR) vaccines. This study evaluated VE of GSK's MMR vaccine ("Priorix") against measles and mumps.

METHODS

This retrospective, case-control study used UK data from the Clinical Practice Research Datalink GOLD linked to the Hospital Episode Statistics database to identify children 1-13 years old diagnosed with measles or mumps from January 2006 to December 2018. Cases were matched to controls according to birth month/year and practice region. Cases were identified using clinical codes (without laboratory confirmation). "Priorix" exposure was identified using vaccine batch identifiers. Children exposed to other MMR vaccines were excluded. Adjusted VE was estimated for ≥1 vaccine dose in all children, and for 1 dose and ≥2 doses in children ≥4 years at diagnosis.

RESULTS

Overall, 299 measles cases matched with 1196 controls (87.6% <4 years old), and 243 mumps cases matched with 970 controls (74.2% <4 years old) were considered. VE for ≥1 dose in all children was 78.0% (97.5% confidence interval: 67.2%-85.3%) for measles and 66.7% (48.1%-78.6%) for mumps. In children ≥4 years old, VE after 1 dose was 74.6% (-21.7% to 94.7%) for measles and 82.3% (32.7%-95.3%) for mumps, and VE after ≥2 doses was 94.4% (79.7%-98.5%) for measles and 86.5% (64.0%-94.9%) for mumps.

CONCLUSIONS

"Priorix" is effective in preventing measles and mumps in real-life settings.

Sero-survey of measles virus antibodies among symptomatic children attending Abuja Teaching Hospital, Nigeria

Background: Nigeria is one of the countries with a high prevalence of measles outbreak in children under 5 years old, despite a history of vaccination. This study aims to determine the prevalence of anti-measles virus IgM and IgG among children under 5 years attending the University of Abuja Teaching Hospital (UATH), Gwagwalada, FCT Abuja, Nigeria.

Materials and methods: Whole blood was collected, centrifuged, and serum anti-IgM and anti-IgG against measles virus was analysed using ELISA. Sociodemographic variables and vaccination history of subjects were obtained by interview-based questionnaires.

Results: The overall anti-Measles virus IgG and IgM seroprevalences were 29.2% and 14.6%, respectively. The prevalence of measles IgG was significantly associated with the parent’s employment status (X²=11.67, p=0.008). However, the prevalence of measles virus IgM was significantly associated with children’s age (X²=16.62, p=0.002), parents’ employment status and children’s vaccination status (X² =7.72, p=0.02).

Conclusion: A majority of study participants were not immunised against measles, and a significant number of participants had serological evidence of acute measles virus infection. There is a need for more concerted and massive measles vaccination of children.

Socio-demographic correlates of first dose of measles (MCV1) vaccination coverage in India

Background

Between 2010 and 2018, measles-related mortality had halved in India mainly with effective measles vaccination campaigns and widespread coverage across the states and population subgroups. Despite the commendable vaccination coverage, 2.9 million children in India missed the first dose of measles vaccine (MCV1) in 2017, and many of those vaccinated were not vaccinated at the recommended age (i.e. between 9 and 12 months). This study analyzed pattern and correlates of MCV1 coverage and MCV1 administration at recommended age among children aged 12–23 months in India.

Methods

We used the official data from the recent round of National Family Health Survey (NFHS-4), a nationally representative cross-sectional household survey in India conducted in 2015–16. Descriptive statistics and logistic regression analysis were applied to ascertain the influence of specified socio-demographic variables affecting measles vaccination coverage in India.

Results

The study revealed the distinct variations in coverage of MCV1 between the districts of India. There were also major challenges with age recommended vaccination, with about 15% of eligible children not vaccinated within the recommended age range, attributable to several socio-demographic factors. Significantly, antenatal care utilization of mothers strongly influenced MCV1 coverage and age recommended MCV1 coverage in India. The study also identified that children who missed MCV1 had one or more adverse health risks such as malnutrition, anemia and diarrhea disease.

Conclusions

A socio-economic gradient exists in India’s MCV1 coverage, mediated by antenatal visits, education of mothers, and highlighted socio-demographic factors. Infection with measles was significantly correlated with greater anthropometric deficits among the study cohort, indicating a wider range of benefits from preventing measles infection. Eliminating morbidity and mortality from measles in India is feasible, although it will require efficient expanded program on immunization management, enhanced health literacy among mothers, continuing commitment from central state and district political authorities.

Are vaccinated measles cases protected against severe disease?

OBJECTIVES

We aimed to estimate vaccine effectiveness against severe measles based on the number of vaccine doses administered and the time since last vaccination.

PATIENTS AND METHODS

We included measles cases aged at least 2 years and born since 1980 who were notified in France between 2006 and mid-2019. We considered two severity levels (moderate, severe) and calculated adjusted relative risks (aRR) using multinomial logistic regression.

RESULTS

We included 10,399 cases. The risk of severe measles in two-dose vaccine recipients was 71% (aRR = 0.29 [95%CI 0.12-0.72]) and 83% (aRR = 0.17 [95%CI 0.04-0.70]) lower than in unvaccinated cases, if the time since last dose was less or more than 15 years, respectively. The risk of moderate disease followed a similar pattern.

CONCLUSIONS

Two-dose measles vaccination provided long-term protection against severe cases, even after vaccine failures. These findings underscore the need for compliance to the recommended measles vaccination schedule to prevent severe cases.

Susceptibility to measles in migrant population: implication for policy makers

BACKGROUND

Despite a large measles outbreak is taking place in WHO European region, currently no data are available on measles immunization coverage in the asylum seeker and migrants hosted in this area.

METHODS

Two hundred and fifty-six migrants upon their arrival in Italy on March, April and May 2016 were screened for measles virus IgG antibodies by chemiluminescence immunoassay (Liaison XL analyzer, Diasorin, Italy). The virus susceptibility in this cohort, the differences between the official country reported and the observed measles immunization coverage and the impact of current measles outbreak on the asylum seekers hosted in the largest Asylum Seeker centres of Italy, were evaluated.

RESULTS

The prevalence of subjects with positive result for measles IgG antibodies ranged between 79.9% and 100%. In Senegal, Mali, Nigeria, Pakistan and Bangladesh, the measles IgG seroprevalence observed was greater than the vaccinal coverage reported by WHO after I dose of vaccine. Based on data regarding the II dose coverage, the ASs population presented a seroprevalence greater to that expected.

CONCLUSION

On the basis of the results obtained, extraordinary screening and vaccination campaigns in the migrant population, especially in the course of large outbreaks, could represent a resource to reach an adequate measles immunization coverage and to control this infectious disease.

Evaluation of the Measles Surveillance System in Kaduna State, Nigeria (2010-2012)

Objective

To evaluate the case-based measles surveillance system in Kaduna State of Nigeria and identify gaps in its operation.

Introduction

In Africa, approximately 13 million cases, 650,000 deaths due to measles occur annually, with sub-Saharan Africa having the highest morbidity and mortality. Measles infection is endemic in Nigeria and has been documented to occur all year round, despite high measles routine and supplemental immunization coverage. The frequent outbreaks of measles in Kaduna State prompted the need for the evaluation of the measles case-based surveillance system.

Methods

We interviewed stakeholders and conducted a retrospective record review of the measles case-based surveillance data from 2010 – 2012 and adapted the 2001 CDC guidelines on surveillance evaluation and the Framework for Evaluating Public Health Surveillance Systems for Early Detection of Outbreaks, to assess the systems usefulness, representativeness, timeliness, stability, acceptability and data quality. We calculated the annualized detection rate of measles and non-measles febrile rash, proportion of available results, proportion of LGAs (Districts) that investigated at least one case with blood, proportion of cases that were IgM positive and the incidence of measles. We compared the results with WHO(2004) recommended performance indicators to determine the quality and effectiveness of measles surveillance system.

Results

According to the Stakeholders, the case-based surveillance system was useful and acceptable. Median interval between specimen collection and release of result was 7days (1 – 25 days) in 2010, 38 days (Range: 16 – 109 days) in 2011 and 11 days (Range: 1 – 105 days) in 2012. The annualized detection rate of measles rash in 2010 was 2.1 (target: ³2), 1.0 (target: ³2) in 2011 and 1.4 (target: ³2) in 2012. The annualized detection rate of non-measles febrile rash in 2010 was 2.1 (target: ³2), 0.6 (target: ³2) in 2011 and 0.8 (target: ³2) in 2012. Case definitions are simple and understood by all the operators.

Conclusion

This evaluation showed that the surveillance system was still useful. Also, the efficiency and effectiveness of the laboratory component as captured by the “median interval between specimen collection and the release of results improved in 2010 and 2012 compared to 2011. However, there was a progressive decline in the timeliness and completeness of weekly reports in the years under review.

FIRST MOLECULAR DETECTION AND VP7 (G) GENOTYPING OF GROUP A ROTAVIRUS BY SEMI-NESTED RT-PCR FROM SEWAGE IN NIGERIA

Rotavirus is the leading cause of viral gastroenteritis worldwide, and sewage is a major source of the virus dissemination in the environment. Our aim was to detect and genotype rotaviruses from sewages in Nigeria. One hundred and ninety sewage samples were collected between June 2014 and January 2015. The two phase concentration method using PEG 6000 and dextran was used to concentrate sewage samples following WHO protocols. Molecular detection was performed by RT-PCR, and VP7 genotyping by semi-nested multiplex PCR. A total of 14.2% (n = 27) samples tested positive. Monthly distribution showed that June to September had a lower rate (3.7% to 7.4%), while October to January recorded 11% to 26%. Genotype G1 predominated followed by G8, G9, G4 and lastly G2, 7.4% (n = 2) of isolates were nontypeable. This is the first report of rotavirus detection in sewages from Nigeria. Genotype G1 remains the most prevalent genotype. This observation calls for an effort by the governmental authorities to implement a molecular surveillance, both clinical and environmental, in order to provide vital information for the control and the vaccine efficacy not only in Nigeria, but globally.