Trends and spatial distribution of MMR vaccine coverage in Brazil during 2007–2017

Risk classification for the transmission of vaccine-preventable diseases in the state of Minas Gerais, Brazil: 2018 to 2022

The National Immunization Program (PNI) is one of Brazil's most significant public health interventions. However, recent years have witnessed a progressive decline in vaccination coverage despite the success of the PNI and the expansion of Primary Health Care (PHC), the main point of entry for the population into health services. To address this challenge, broader strategies are needed, such as identifying areas at high risk for the transmission of vaccine-preventable diseases. This study aimed to analyze the risk classification for the transmission of vaccine-preventable diseases in the 853 municipalities of Minas Gerais, Brazil, from 2018 to 2022. This epidemiological time-series study uses secondary data on vaccination coverage, dropout rates, and homogeneity of the recommended immunobiologicals for children under 2 years of age from 2018 to 2022 in Minas Gerais. We obtained the data from the National Immunization Program Information System (SIPNI). The study highlighted a decline in vaccination coverage from 2018 to 2021, with a significant drop following the COVID-19 pandemic in 2020. According to the risk classification for the transmission of vaccine-preventable diseases, the proportion of municipalities classified as high and very high risk remained stable from 2018 to 2019, increased from 2019 to 2020 and from 2020 to 2021, and decreased from 2021 to 2022. We observed the public health impact not only regarding COVID-19 but also on most vaccine-preventable diseases. Given the scenario of declining vaccination coverage and the risk of a resurgence of vaccine-preventable diseases exacerbated by the COVID-19 pandemic, health services must implement public health strategies to mitigate this situation. Risk classification proved to be an effective methodology for prioritizing locations for health interventions. It enabled the analysis of the vaccination scenario in the state following the implementation of a participatory action research project conducted jointly by academia and health services.

Temporal and spatial analysis of over 7,000 measles cases outbreak from 2018 to 2019 in the Brazilian Amazon

OBJECTIVE

This study aimed to present a temporal and spatial analysis of the 2018 measles outbreak in Brazil, particularly in the metropolitan city of Manaus in the Amazon region, and further introduce a new tool for spatial analysis.

METHODS

We analyzed the geographical data of the residences of over 7,000 individuals with measles in Manaus during 2018 and 2019. Spatial and temporal analyses were conducted to characterize various aspects of the outbreak, including the onset and prevalence of symptoms, demographics, and vaccination status. A visualization tool was also constructed to display the geographical and temporal distribution of the reported measles cases.

RESULTS

Approximately 95% of the included participants had not received vaccination within the past decade. Heterogeneity was observed across all facets of the outbreak, including variations in the incubation period and symptom presentation. Age distribution exhibited two peaks, occurring at one year and 18 years of age, and the potential implications of this distribution on predictive analysis were discussed. Additionally, spatial analysis revealed that areas with the highest case densities tended to have the lowest standard of living.

CONCLUSION

Understanding the spatial and temporal spread of measles outbreaks provides insights for decision-making regarding measures to mitigate future epidemics.

Temporal trend of the dropout rate and vaccination coverage of the triple viral vaccine in Brazil, 2014-2021

MAIN RESULTS

Annual vaccination coverage was below 95% in Brazil. The second dose of the vaccine showed stationary and decreasing trends in the country's Federative Units. The dropout rate varied greatly throughout the study period.

IMPLICATIONS FOR SERVICES

The results found regarding the trends serve to inform and point to the urgency of planning actions aimed at improving coverage of the triple viral vaccine nationally in Brazil.

PERSPECTIVES

Investments in enhanced training of epidemiological surveillance professionals and enhanced computerized systems are necessary, with a view to continuous monitoring, to support actions to promote better and timely vaccine coverage.

OBJECTIVE

to analyze the temporal trend of coverage and dropout rate for triple viral vaccine in Brazil, according to the country's Federative Units and Macro-Regions, between 2014 and 2021.

METHODS

this was an ecological time series study, using data from the National Immunization Program Information System and the Live Birth Information System; joinpoint regression models were used.

RESULTS

in Brazil as a whole annual vaccination coverage was below 95% and ranged from 92.3% (2015) to 54.4% (2021); the second dose of the vaccine showed a decreasing temporal trend in the period (average change over the period = -5.8; 95%CI -10.5;-0.8); the temporal trends were stationary and decreasing in the country's Federative Units; the dropout rate ranged from 22.2% (2014) to 37.4% (2021).

CONCLUSION

there was a downward trend in vaccination coverage and an increase in the dropout rate in Brazil as a whole and in the country's Federative Units.

Temporal and spatial distribution trends of polio vaccine coverage in less than one-year old children in Brazil, 2011-2021

BACKGROUND

Low polio vaccine coverage can result in the spread of Poliovirus to areas free from viral circulation. This study analyzed the temporal trends and spatial distribution of polio vaccine coverage in one year-old children in Brazil, between 2011 and 2021.

METHODS

This was an ecological, time-series study (2011 to 2021) with annual vaccine coverages against poliomyelitis, extracted from the Information System of the National Immunization Program from the 26 States and the Distrito Federal (DF). The percentage reductions in vaccination coverage in Brazil and in the Regions were calculated. Prais-Winsten regression models were used to analyze time series for the Regions and States, and spatial analysis identified the distribution of clusters (high-high; low-low; high-low and low-high) of vaccination coverages across Brazilian municipalities, using a 5% significance level.

RESULTS

From 2011 to 2021, the coverage of polio vaccines decreased by 29,9%. There was a progressive increase observed in clusters resulting in low vaccination coverages (140 low-low Brazilian municipalities in 2011 vs. 403 in 2021), mostly reported in the North and Northeast regions of the country. There was a downward trend in vaccination coverages in 24 of the 26 States and DF (p ≤ 0.05).

CONCLUSIONS

The reduction in polio vaccine coverage, as observed in the North and Northeast regions of Brazil, may favor the spread of Poliovirus. Therefore, vaccination strategies should be prioritized for children residing in areas with sharp and recurrent declines in vaccination coverages, including travelers, migrants, and refugees.

Associated factors with vaccine hesitancy in mothers of children up to two years old in a Brazilian city

This study aims to evaluate maternal vaccine hesitancy and its associated factors. This is a cross-sectional study of a probabilistic sample of 450 mothers of children born in 2015, living in a Brazilian city, and who was, at the time of data collection, more than two years old. We used the tool proposed by the World Health Organization (10-item Vaccine Hesitancy Scale). To assess its structure, we performed, exploratory and confirmatory factor analyses. We performed linear regression models to evaluate the factors associated with vaccine hesitancy. The factor analysis showed two components for the vaccine hesitancy scale: lack of confidence in vaccines and risk perception of vaccines. High family income was associated with lower vaccine hesitancy (greater confidence in vaccines and lower risk perception of vaccines), while the presence of other children, regardless of birth order, in the family was associated with lower confidence in vaccines. A good rapport with health professionals, willingness to wait for the vaccination and the getting vaccinated through campaigns were associated with greater confidence in vaccines. The deliberate delay or decision not to vaccinate their children and previous experience with adverse reactions to the vaccine were associated with lower confidence in vaccines and greater risk perception of vaccines. Health care providers, especially nurses, play a relevant role to address vaccine hesitancy, guiding vaccination through a trustworthy rapport.

[Transmission risk classification for vaccine-preventable diseases in Minas Gerais, Brazil: two years since the onset of the COVID-19 pandemic]

The scope of this study is to analyze the risk classification of transmission of vaccine-preventable diseases (VPDs) in the 853 municipalities in the state of Minas Gerais (MG) two years after the onset of the COVID-19 pandemic. It is an epidemiological study with secondary data on vaccination coverage and dropout rate of ten immuno-biologicals recommended for under 2-year-old children in 2021 in MG. With respect to the dropout rate, this indicator was only evaluated for the multidose vaccines. After calculating all the indicators, the municipalities of the state were classified according to the transmission risk of VPDs into five categories: very low, low, medium, high, and very high risk. Minas Gerais had 80.9% of municipalities classified as high transmission risk for VPDs. Regarding the homogeneity of vaccination coverage (HCV), large municipalities had the highest percentage of HCV classified as very low, and 100% of these municipalities were classified as high or very high risk for transmission of VPDs, with statistical significance. The use of immunization indicators by municipality is effective for the classification of the scenario of each territory and the proposal of public policies seeking to increase vaccination coverage.

Measles vaccination in Brazil: where have we been and where are we headed?

Abstract The re-emergence of vaccine-preventable diseases due to the decline in vaccine coverage (VC) has been documented in several countries. The objective was to analyze the VC, the homogeneity of VC, and measles cases in Brazil from 2011 to 2021, focusing on the period of the COVID-19 pandemic, its temporal trend, space-time distribution, and factors associated with clusters of lower VC. This is an ecological study on measles VC (dose 1), with methods of interrupted time series and evaluation of spatio-temporal disposition, through the sweep test to identify clusters of VC. Starting in 2015, we observe a progressive decline in VC and homogeneity, with an accentuation after 2020, in all regions, particularly in the North and Northeast. Low VC clusters were associated with worse human development indicators, social inequality, and less access to the Family Health Strategy. In Brazil, the pandemic intensified health inequalities with low VC of measles in socially more vulnerable and unequal municipalities. There is a risk of virus circulation, however, the challenge of strengthening primary care, improving health communication and guaranteeing access to the vaccine, reducing missed opportunities for vaccination and vaccine hesitancy, is highlighted.

Measles vaccination in Brazil: where have we been and where are we headed?

The re-emergence of vaccine-preventable diseases due to the decline in vaccine coverage (VC) has been documented in several countries. The objective was to analyze the VC, the homogeneity of VC, and measles cases in Brazil from 2011 to 2021, focusing on the period of the COVID-19 pandemic, its temporal trend, space-time distribution, and factors associated with clusters of lower VC. This is an ecological study on measles VC (dose 1), with methods of interrupted time series and evaluation of spatio-temporal disposition, through the sweep test to identify clusters of VC. Starting in 2015, we observe a progressive decline in VC and homogeneity, with an accentuation after 2020, in all regions, particularly in the North and Northeast. Low VC clusters were associated with worse human development indicators, social inequality, and less access to the Family Health Strategy. In Brazil, the pandemic intensified health inequalities with low VC of measles in socially more vulnerable and unequal municipalities. There is a risk of virus circulation, however, the challenge of strengthening primary care, improving health communication and guaranteeing access to the vaccine, reducing missed opportunities for vaccination and vaccine hesitancy, is highlighted.

[Vaccination coverage in children under one year of age in Minas Gerais state, Brazil]

The scope of this article is to analyze vaccination coverage rates in children under one year of age during the period from 2015 to 2020 in the state of Minas Gerais (MG). It involved an ecological, time-series study on vaccination coverage in children under 1 year of age, considering the 28 Regional Health Management/Superintendencies (GRS/SRS) of MG as the unit of analysis. The following immunobiological vaccine coverage was analyzed: Bacillus Calmette and Guérin, human rotavirus, pneumococcal 10, pentavalent, meningococcus C, yellow fever, and polio vaccines. The Prais-Winsten autoregressive model was employed for trend analysis. The year 2020 stands out, as it presented the lowest proportion of GRS and SRS that reached the recommended vaccine coverage goals for the immunobiologicals analyzed. Regarding the analysis of the coverage trend, 8 of the 28 GRS/SRS showed a decreasing trend for at least 5 of the 7 immunobiologicals evaluated. We observed a downward trend in the vaccination coverage of at least five immunobiologicals in eight of the GRS/SRS, with emphasis on the Pentavalent vaccine, which showed a downward trend in vaccination coverage in 60.71% of the GRS and SRS.

Changing demographics and immunity to vaccine preventable diseases in people with HIV in Ireland

BACKGROUND

HIV infection is associated with an increased risk of morbidity and mortality from vaccine preventable infections. This research describes, in the context of changing patient demographics, the seroprevalence of vaccine preventable viral infections among attendees of the largest centre for HIV positive patients in Ireland.

METHODS

Baseline serum IgG results for measles, mumps, rubella, varicella zoster virus (VZV) & hepatitis A, as well as hepatitis B sAg, cAb and sAb results, were retrieved for 2534 clinic attendees attending in 2018. Results were available for between 990 and 2363 attendees (39-93%), depending on the test, and were compared with 2013 clinic data.

RESULTS

There was a 35% increase in attendees in 2018 when compared to 2013. The largest increase was in attendees of South American origin. In 2018, males accounted for 73% of the entire cohort and the HIV acquisition risk for 48% of attendees was MSM. 47% of attendees were originally from Ireland. Among those tested, 33% were susceptible to at least one component of the MMR vaccine. 5% were VZV non-immune (significantly associated with younger age and the acquisition risk status of injection drug use). 21% were hepatitis A non-immune (significantly associated with younger age and being of European or South American origin). 32% were hepatitis B cAb seropositive (significantly associated with older age, injection drug use status and being originally from Africa). 3% demonstrated hepatitis B sAg positivity. 64% had hepatitis B sAb ≥ 10mIU.

CONCLUSION

In a cohort of attendees to an HIV clinic in a large urban setting, the susceptibility to several common vaccine preventable viral infections, in particular MMR and hepatitis A and B, was high. These results highlight the importance of proactive screening and immunisation to help protect this high risk patient group against vaccine preventable diseases.

Yellow fever vaccination before and during the covid-19 pandemic in Brazil

OBJECTIVE

To analyze the number of yellow fever vaccine doses administered before and during the covid-19 pandemic in Brazil.

METHODS

This is an ecological, time series study based on data from the National Immunization Program. Differences between the median number of yellow fever vaccine doses administered in Brazil and in its regions before (from April/2019 to March/2020) and after (from April/2020 to March/2021) the implementation of social distancing measures in the country were assessed via the Mann-Whitney test. Prais-Winsten regression models were used for time series analyses.

RESULTS

We found a reduction in the median number of yellow fever vaccine doses administered in Brazil and in its regions: North (-34.71%), Midwest (-21.72%), South (-63.50%), and Southeast (-34.42%) (p < 0.05). Series showed stationary behavior in Brazil and in its five regions during the covid-19 pandemic (p > 0.05). Brazilian states also showed stationary trends, except for two states which recorded an increasing trend in the number of administered yellow fever vaccine doses, namely: Alagoas State (before: β = 64, p = 0.081; after: β = 897, p = 0.039), which became a yellow fever vaccine recommendation zone, and Roraima State (before: β = 68, p = 0.724; after: β = 150, p = 0.000), which intensified yellow fever vaccinations due to a yellow fever case confirmation in a Venezuelan State in 2020.

CONCLUSION

The reduced number of yellow fever vaccine doses administered during the covid-19 pandemic in Brazil may favor the reemergence of urban yellow fever cases in the country.

Evolution of the quality of prenatal care in the primary network of Brazil from 2012 to 2018: What can (and should) improve?

The article describes the temporal evolution of prenatal quality indicators in the primary health care network in Brazil and investigates regional differences. This study used data from the external evaluation of Brazil's National Program for Improving Primary Care Access and Quality (PMAQ) with health teams participating in Cycles I, II and III of the Program, carried out respectively in 2012, 2013/14 and 2017/18. The number of visits, physical examination procedures, guidelines and request for laboratory tests were investigated. There was a positive evolution for tests-HIV, syphilis, blood glucose and ultrasound, and for all tests, guidance on feeding and weight gain of the baby and examination of the oral cavity. The indicators that performed the worst were: performance of tetanus vaccine, six or more visits, receiving guidance on exclusive breastfeeding and care for the newborn, and the procedures-all, measurement of uterine height, gynecological exam and cervix cancer prevention. These changes had a varied behavior between the regions of the country.

COVID-19 vaccine prioritization based on district classification in Yogyakarta Province, Indonesia

Due to limited availability, Indonesia's coronavirus disease 2019 (COVID-19) vaccination will be done in 4 stages until herd immunity has been reached. Yogyakarta, an education and tourist destination, needs to get a specific, spatial estimation of the exact need for COVID-19 vaccination without delay. This study sheds light on identifying which districts should be prioritized at each vaccination phase. Secondary data collected from provincial, and county-level statistical agencies were quantitatively calculated by the Z-Score method. The results indicate that the first phase of vaccination should prioritize Pengasih and Sentolo districts in Kulon Progo Regency, which have a large number of health workers; the districts of Depok, Banguntapan, Piyungan, Sewon, Wonosari, Gamping, Mlati and Ngaglik should be done in the second phase based on the fact that these districts have many public service officials as well as elderly people; Umbulharjo and Depok districts will be approached in the third phase since they have more vulnerable groups and facilities that may promote COVID- 19 transmission during their daily activities; while the fourth phase should focus on the districts of Banguntapan, Sewon, Kasihan, Gamping, Mlati, Depok, and Ngaglik due to the intensity of COVID-19 clusters discovered there. Overall, vaccination would be given the priority in the districts with the largest number of people in need, i.e., public service officers, elderly people and those likely to be exposed to the coronavirus causing COVID-19.

Fake news and covid-19: a concern due to the low vaccine coverage in Brazil

Abstract This study comprised the application of a survey in São Paulo, Brazil, in 2 different periods of 2020: the beginning of the covid-19 pandemic and the disease’s first peak (from March to April, 100 interviews) to the time of stability in case fatality rates (from May to July, 100 interviews); the questionnaire included was composed of 14 multiple-choice questions to evaluate the importance of mass communication channels, including social media, and the level of importance attributed to preventive measures at the beginning of the pandemic. The changes in people’s behavior, even in a group with more schooling, which initially considered preventive measures to be very important (91%) but, in the second survey, was reduced to 82%. The reinforcement of preventive measures to reduce cases and deaths by covid-19 in Brazil is urgent, allied to recommendations with clear information on the importance of vaccination to avoid low rates as the current situation of vaccine coverage for preventable diseases.

Number of doses of Measles-Mumps-Rubella vaccine applied in Brazil before and during the COVID-19 pandemic

Background

Due to the social isolation measures adopted in an attempt to mitigate the risk of transmission of SARS-CoV-2, there has been a reduction in vaccination coverage of children and adolescents in several countries and regions of the world.

Objective

Analyze the number of doses of vaccine against Measles-Mumps-Rubella (MMR) applied before and after the beginning of mitigation measures due to COVID-19 pandemic in Brazil.

Methods

The data collected refer to the number of doses of the MMR vaccine applied monthly to the target population residing in Brazil: cahildren, aged 12 months (first dose) and children, aged 9 years (second dose), from April 2019 to December 2020. Differences in MMR vaccine doses from April 2019 to March 2020 (before the start of mitigation measures) and April 2020 to September 2020 (after the start of the mitigation measures) were evaluated. Spatial analysis identified clusters with a high percentage of reduction in the median of applied doses no Brazil.

Results

There was a reduction in the median of doses applied in the Regions North (− 33.03%), Northeast (− 43.49%) and South (− 39.01%) e nos Estados Acre (− 48.46%), Amazonas (− 28.96%), Roraima (− 61.91%), Paraíba (− 41.58%), Sergipe (− 47.52%), Rio de Janeiro (-59.31%) and Santa Catarina (− 49.32) (p < 0.05). High-high type spatial clusters (reduction between 34.00 and 90.00%) were formed in the five regions of Brazil (Moran’s I = 0.055; p = 0.01).

Conclusion

A reduction in the number of MMR vaccine doses was evidenced as a possible effect by the restrictive actions of COVID-19 in Brazil.

Missed childhood immunizations during the COVID-19 pandemic in Brazil: Analyses of routine statistics and of a national household survey

INTRODUCTION

There is widespread concern that disruption to health services during the COVID-19 pandemic has led to declines in immunization coverage among young children, but there is limited information on the magnitude of such impact. High immunization coverage is essential for reducing the risk of vaccine preventable diseases.

METHODS

We used data from two nationwide sources covering the whole of Brazil. Data from the Information System of the National Immunization Program (SIPNI) on the monthly number of vaccine doses administered to young children were analyzed. The second source was a survey in 133 large cities in the 27 states in the country, carried out from August 24-27. Respondents answered a question on whether children under the age of three years had missed any scheduled vaccinations during the pandemic, and available vaccination cards were photographed for later examination.

RESULTS

SIPNI data showed that, relative to January and February 2020, there was a decline of about 20% in vaccines administered to children aged two months or older during March and April, when social distancing was at the highest level in the country. After May, vaccination levels returned to pre-pandemic values. Survey data, based on the interviews and on examination of the vaccine cards, showed that 19.0% (95% CI 17.0;21.1%) and 20.6% (95% CI 19.0;23.1%) of children, respectively, had missed immunizations. Missed doses were most common in the North (Amazon) region and least common in the South and Southeast, and also more common among children from poor than from wealthy families.

INTERPRETATION

Our results show that the pandemic was associated with a reduction of about 20% in child vaccinations, but this was reverted in recent months. Children from poor families and from the least developed regions of the country were most affected. There is an urgent need to booster immunization activities in the country to compensate for missed doses, and to reduce geographic and socioeconomic inequalities.

Evaluating the cost-effectiveness of maternal pertussis immunization in low- and middle-income countries: A review of lessons learnt

This issue of Vaccine is devoted to papers from a research project that developed two types of simulation models, static and dynamic transmission, to evaluate the cost-effectiveness of maternal immunization to prevent pertussis in infants in low- and middle-income countries (LMICs). The research was conducted by a multinational team of investigators and funded by the Bill & Melinda Gates Foundation to gain an understanding of when and where maternal immunization might be a good public health investment for LMICs. Here we review the project's central lessons for vaccine policy and research. Models require a lot of data. As most LMICs lack good data, the models were built using pertussis disease burden data from Brazil, a middle-income country with three long-established, independent information systems (disease surveillance, hospitalization, and mortality), on the hypothesis that the disease process is similar across countries. Values for key parameters, particularly infant mortality, infant vaccine coverage, and costs of vaccination and treatment, were then varied to represent other LMICs. The results show that coverage levels of infant whole cell pertussis (wP) vaccine are key to the cost-effectiveness of maternal pertussis immunization. In settings where infant wP coverage is below the threshold thought necessary to eliminate pertussis in the population, 90-95%, maternal immunization is cost-effective, even cost-saving. By contrast, it is very expensive in countries capable of maintaining infant vaccination in or above the threshold range. The research also suggests that, while static models may serve to explore an intervention's cost-effectiveness initially, dynamic transmission models are essential for more accurate estimates. These findings can help guide policies toward maternal pertussis immunization, but also show that developing better data on neonatal pertussis mortality burden and infant vaccine coverage in LMICs, and on the duration of immunity of currently available pertussis vaccines, are key priorities to support better vaccine policy.

Human parvovirus B19: a review of clinical and epidemiological aspects in Brazil

Since the first evidence of human parvovirus B19 (B19V) infection in late 80s, several studies have been conducted to clarify the spectrum of clinical diseases in Brazil. B19V infection is prevalent in the general population and has exhibited a cyclical pattern of occurrence every 4-5 years, with the predominance of genotype 1 over 3b. During epidemic periods the wide range of clinical conditions, such as ertythema infectiosum, arthropathy, transient aplastic crisis, nonimmune hydrops fetalis and B19V-hepatitis were diagnosed. However, many infections are likely asymptomatic or have a self-limiting clinical course and are not readly diagnosed. Besides, the similarity of the symptoms of ertythema infectiosum to other rash diseases and the broadly circulation of arboviruses makes differential diagnosis more difficult. In this article, we provide a historical comprehensive overview of the research on parvovirus B19 conducted in Brazil, with a focus on the clinical and epidemiological aspects of the infection.

Pandemic and vaccine coverage: challenges of returning to schools

Since March 2020, Brazil has faced the pandemic of the coronavirus disease 2019 (Covid-19), which has severely modified the way in which the population lives and uses health services. As such, face-to-face attendance has dropped dramatically, even for child vaccination, due to measures of social distancing to mitigate the transmission of the virus. Several countries have recorded a substantial drop in vaccination coverage in children, especially of those under two years of age. In Brazil, administrative data indicate the impact of the covid-19 pandemic on this downward trend, which was already an important challenge of the National Immunization Program in recent years. Many children will be susceptible to immunopreventable diseases, which reinforces the need to assess the vaccine status of schoolchildren before returning to face-to-face classes.

Using models to shape measles control and elimination strategies in low- and middle-income countries: A review of recent applications

After many decades of vaccination, measles epidemiology varies greatly between and within countries. National immunization programs are therefore encouraged to conduct regular situation analyses and to leverage models to adapt interventions to local needs. Here, we review applications of models to develop locally tailored interventions to support control and elimination efforts. In general, statistical and semi-mechanistic transmission models can be used to synthesize information from vaccination coverage, measles incidence, demographic, and/or serological data, offering a means to estimate the spatial and age-specific distribution of measles susceptibility. These estimates complete the picture provided by vaccination coverage alone, by accounting for natural immunity. Dynamic transmission models can then be used to evaluate the relative impact of candidate interventions for measles control and elimination and the expected future epidemiology. In most countries, models predict substantial numbers of susceptible individuals outside the age range of routine vaccination, which affects outbreak risk and necessitates additional intervention to achieve elimination. More effective use of models to inform both vaccination program planning and evaluation requires the development of training to enhance broader understanding of models and where feasible, building capacity for modelling in-country, pipelines for rapid evaluation of model predictions using surveillance data, and clear protocols for incorporating model results into decision-making.

Measles, rubella, mumps and Toxoplasma gondii antibodies in saliva of vaccinated students of schools and universities in São Paulo City, Brazil

Introduction

Vaccines are well-established public health interventions with major impact on the prevalence of infectious diseases, but outbreaks are occurring frequently due to primary and secondary failures, despite high coverage. Surveillance of efficacy and duration of induced immunity is a difficult task as it requires invasive blood sampling in children and teenagers. Saliva can be an acceptable alternative source of IgG to assess vaccine efficacy and toxoplasmosis incidence. We investigated IgG response for measles, mumps, rubella, and T. gondii in saliva samples of vaccinated young people.

Methods

Saliva was collected from 249 public schools students from São Paulo, Brazil, aged 7 to 13 years old, during an interactive exhibition on hygiene. We used S. aureus protein A solid phase capture assay for IgG reactive to biotinylated purified proteins. Paired saliva and serum (47) were tested from young adults with serum evidence of T. gondii infection and from negative children less than 12 month old for standardization. Reproducibility was greater than 98% and sensitivity and specificity of the saliva assays were greater than 95%, as well as the concordance of paired saliva and serum samples.

Results

Saliva from high school students showed a prevalence of 8.5% (95% CI: 5.0–11.9%) for anti T. gondii IgG; 96.8% (94.6–99%) of anti-measles IgG; 59.1% (53–65%) of anti-rubella IgG, and 57.5% (51.3–63.6%) of anti-mumps IgG.

Discussion

The prevalence of antibodies against mumps and rubella after 6–8 years of vaccination was lower than against measles among students. The findings of this study demonstrate the feasibility of saliva sampling for follow-up of vaccine immune status in teenagers. This useful approach allows for IgG detection for vaccine control or epidemiological studies.

The 2019 Pan American games: Communicable disease risks and travel medicine advice for visitors to Peru - Recommendations from the Latin American Society for Travel Medicine (SLAMVI)

The next Pan American Games will be held in Peru in the period July-August 2019. Around 6680 participants from 41 countries are expected to take part in the event. There will be a total of 62 sport disciplines. This event poses specific challenges, given its size and the diversity of attendees. Such gatherings also have potential for the transmission of imported or endemic communicable diseases, including measles in view of the global outbreak situation, but also tropical endemic diseases. In anticipation of increased travel, a panel of experts from the Latin American Society for Travel Medicine (SLAMVI) developed the current recommendations taking into consideration the epidemiology and risks of the main communicable diseases at potential destinations in Peru, recommended immunizations and other preventives measures. These recommendations can be used as a basis for advice for travelers and travel medicine practitioners. Mosquito-borne infections also pose a challenge. Although Lima is malaria free, travelers visiting Peruvian high-risk areas for malaria should be assessed regarding the need for chemoprophylaxis. Advice on the correct timing and use of repellents and other personal protection measures is key to preventing vector-borne infections. Other important recommendations for travelers should focus on preventing water- and food-borne diseases including travelers' diarrhea. This paper addresses pre-travel, preventive strategies to reduce the risk of acquiring communicable diseases during the Pan American Games and also reviews the spectrum of endemic infections in Lima and Peru to facilitate the recognition and management of infectious diseases in travelers returning to their countries of origin.