Measles outbreak: preliminary report on a case series of the first 8,070 suspected cases, Manaus, Amazonas state, Brazil, February to November 2018

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.

[Maintaining measles elimination status in Colombia during outbreak control, 2019Manutenção do status de eliminação do sarampo na Colômbia durante o controle de surtos, 2019]

Objective

Describe measles outbreaks caused by importation of multiple cases, and the corresponding control interventions.

Methods

Descriptive study of measles outbreaks caused by the importation of multiple cases to Colombia in 2018-2019. Case definitions, classification of source of infection, collection of biological specimens, searches for suspected cases, case identification, and contact tracing were employed. Vaccination records were obtained from vaccination cards or from the Colombian information system. Nationality was determined from records found in the public health surveillance system. The incident command system was used, and response teams and action plans were activated to control outbreaks.

Results

In March 2018, the first case of measles imported from Venezuela was confirmed. Measles incidence in 2018 was 0.2 cases per 100 000 population, and it was 0.3 per 100 000 in 2019. The case fatality rate in 2019 was 0.4%. A total of 214 cases were confirmed in the Venezuelan population (91% with no vaccination history); and 69 outbreaks with no epidemiological link were studied. The MVi/Hulu Langat.MYS/26.11[D8] lineage was identified. Endemic circulation was prevented through innovative interventions such as infection surveillance and control, immediate notification, prioritization of field visits, and transmission risk level criteria.

Conclusions

Colombia controlled measles outbreaks that resulted from imported cases, and it prevented endemic circulation, thereby maintaining certification of measles elimination in the country.

Vaccination against poliomyelitis in Brazil from 2011 to 2021: successes, setbacks, and challenges ahead

The drop in childhood vaccination coverage (VC), including poliomyelitis, has become a health concern. The objective was to analyze the temporal trend of coverage of the three doses of the polio vaccine in the first 12 months of life between 2011 and 2021, in addition to mapping vaccination coverage in Brazil, including the COVID-19 pandemic period. An ecological study was carried out using interrupted time series (STI) techniques and spatial analysis, with data from the National Immunization Program Information System. The VC trend was adjusted by the Newey-West variance estimator according to the federated units and the Brazilian Deprivation Index. The VC distribution was estimated by Bayesian models and the spatial clusters by the global and local Moran index, identifying areas of lower coverage in the health regions. There was a reduction in the VC over the period in all regions, being more pronounced in the North and Northeast regions and during the Covid-19 pandemic. The biggest drops were identified in states and health regions with greater social vulnerability after 2019. The drop in VC shows that the risk of reintroduction of the wild virus is imminent and the challenges need to be faced with the strengthening of the Brazilian Health System (SUS).

Vaccination against poliomyelitis in Brazil from 2011 to 2021: successes, setbacks, and challenges ahead

Abstract The drop in childhood vaccination coverage (VC), including poliomyelitis, has become a health concern. The objective was to analyze the temporal trend of coverage of the three doses of the polio vaccine in the first 12 months of life between 2011 and 2021, in addition to mapping vaccination coverage in Brazil, including the COVID-19 pandemic period. An ecological study was carried out using interrupted time series (STI) techniques and spatial analysis, with data from the National Immunization Program Information System. The VC trend was adjusted by the Newey-West variance estimator according to the federated units and the Brazilian Deprivation Index. The VC distribution was estimated by Bayesian models and the spatial clusters by the global and local Moran index, identifying areas of lower coverage in the health regions. There was a reduction in the VC over the period in all regions, being more pronounced in the North and Northeast regions and during the Covid-19 pandemic. The biggest drops were identified in states and health regions with greater social vulnerability after 2019. The drop in VC shows that the risk of reintroduction of the wild virus is imminent and the challenges need to be faced with the strengthening of the Brazilian Health System (SUS).

Increasing seroprevalence but waning herd immunity against measles after elimination: Longitudinal seroepidemiology of measles in Osaka Prefecture, Japan, 2003-2020

Japan is one of the countries conducting longitudinal serosurveillance of vaccine-preventable diseases. We conducted surveillance of the local measles-specific antibody titer, calculated the effective reproduction number (R_e), and compared data of four terms: term 1, 2003-2006 (before the introduction of the second shot of measles-containing vaccine); term 2, 2007-2010 (early term toward measles elimination); term 3, 2011-2014 (later term toward measles elimination); and term 4, 2015-2020 (after elimination of measles in Japan). Approximately 250 sera from volunteers aged 0 to ≥ 40 years were collected and examined for measles-specific IgG using the gelatin particle agglutination (PA) method annually from 2003 to 2020. Seroprevalence and the geometric mean of the PA antibody titer were examined by term. R_e was calculated using the age-dependent proportion immune and contact matrix for each term. Of the 4,716 sera, 886 in term 1, 1,217 in term 2, 1,069 in term 3, and 1,544 in term 4 were collected. The seroprevalence gradually increased from term 1 (88.3% CI 86.0-90.3) to term 4 (95.7% CI 94.6-96.7), and the seroprevalence of term 1 was significantly lower than those of other terms (Fisher's exact test, p < 0.001), with PA titer ≥ 16 as positive. By contrast, PA antibody titers significantly decreased from term 1 (median 1,024) to term 4 (median 256) (Mann-Whitney U test, p < 0.001). With the protection level (PA titer ≥ 128 and ≥ 256) as positive, R_e gradually increased from term 1 (1.8 and 2.3) to term 4 (2.5 and 4.8, respectively). Waning levels of measles antibodies potentially increase the measles susceptibility in Osaka, Japan. This trend might imply a limitation of vaccine-induced immunity in the absence of a natural booster for wild strains after measles elimination. This study provides a cue for maintaining continuous measles elimination status in the future.

Prevalence of arboviruses and other infectious causes of skin rash in patients treated at a tertiary health unit in the Brazilian Amazon

BACKGROUND

In the clinical course of diseases such as arboviruses, skin rashes may appear, as is often seen in other infectious diseases. The aim of this study was to estimate the prevalence of arboviruses and other infectious causes of skin rash in a tertiary health unit in Manaus, Amazonas state, Western Brazilian Amazon.

METHODOLOGY/PRINCIPAL FINDINGS

This was a cross-sectional study of patients presenting with rash who sought care at Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD) from February 2018 to May 2019. Individuals of either gender, aged over 18 years, were invited to participate voluntarily. Infection by Zika virus (ZIKV), dengue virus (DENV), chikungunya virus (CHIKV), Mayaro virus (MAYV), Oropouche virus (OROV) and measles was evaluated using RT-qPCR (real-time polymerase chain reaction). Immunodiagnostic tests for EBV, CMV, HIV, syphilis, rubella and measles were also performed. A total of 340 participants were included, most were female (228, 67.1%) with an average age of 36.5 years (SD ± 12.2 years). The highest prevalence was of ZIKV monoinfections (65.3%, 222/340), followed by DENV (0.9%, 3/340) and CHIKV infection (0.3%, 1/340). No cases of MAYV, OROV or rubella were found. Other causes of skin rash were detected: measles (2.9%, 10/340), parvovirus B19 (0.9% 3/340), HIV (0.3%, 1/340) and syphilis 0.6% (2/340). The co-infections identified were ZIKV+HIV (0.3%, 1/340), ZIKV+measles (0.3%, 1/340), ZIKV+parvovirus B19 (0.3%, 1/340), ZIKV+EBV (0.3%, 1/340), EBV+parvovirus B19 (0.3%, 1/340), CMV+parvovirus B19 (0.6%, 2/340), CMV+syphilis (0.3%, 1/340), ZIKV+EBV+parvovirus B19 (0.3%, 1/340) and CMV+EBV+parvovirus B19 (0.9%, 3/340). Approximately one quarter of patients had no defined cause for their skin rash (25.3%, 86/340).

CONCLUSIONS

Despite the benign clinical evolution of most of the diseases diagnosed in this series of cases, syndromic surveillance of diseases such as syphilis and HIV are of utmost importance. Periodic serosurveillance might also aid in evaluating the trends of endemic diseases and eventual outbreaks.

Reduced Prevalence of Measles Antibodies in a Cohort of Brazilian Children under 15 Years of Age

Measles is a highly contagious acute febrile disease responsible for sporadic but explosive outbreaks worldwide. Although it was considered eliminated from the Americas, the disease reemerged in 2017. This reemergence was linked to reduced immunization rates. Vaccination, early identification of cases, and blocking of the transmission chain are the most effective tools to combat measles, for which there is not a specific antiviral treatment. In this Brazilian prospective cross-sectional study, we investigated the prevalence of measles antibodies in children, a population vulnerable to significant morbidity and mortality from exposure to infection. Between December 2018 to November 2019, blood samples from 252 children were collected and assessed for the presence of measles-specific IgG antibodies and an overall prevalence of 75.8% was observed. We further stratified the cohort into age subgroups, none of which exhibited antibody presence levels above the herd immunity threshold of 94%. Moreover, the calculated number of secondary cases resulting from a case in any age group ranged from 3 to 4, demonstrating that even with partial vaccination coverage this disease is still concerning and highly transmissible. Despite global warnings about measles and previous efforts to combat the advance of the disease, data on antibody prevalence and vaccination coverage in several countries are still concerning and indicate that significant parts of the population could be affected. Seroprevalence studies like this one are important to highlight actual epidemiological conditions and emphasize the need for additional strategies to encourage immunization and avoid the potential impacts of measles, particularly in children who can be severely affected.

Repercussions of the COVID-19 pandemic on preventive health services in Brazil

INTRODUCTION

The increasing burden of non-communicable diseases and limited public financing are major challenges facing health care systems in Latin America. Although COVID-19 severely impacted the Brazilian health care system, it is crucial to further characterize the degree of disruption caused to public health efforts, in order to address and manage long term effects of this pandemic. We therefore quantified the demand for preventive and treatment services from the Brazilian Unified Health System (Sistema Único de Saúde/SUS) in 2020 to evaluate potential repercussions of COVID-19 in this setting.

METHODS

Using the SUS database, we compared preventative and treatment services rendered in 2020 to the same services rendered from 2017 to 19. We also evaluated the frequency of respiratory infection (RI) diagnoses during the pandemic, relative to the preceding years.

RESULTS

Compared to 2017-19, in 2020 non-urgent medical appointments decreased 1.4-fold (p = 0.0017), dental consultations 2.8-fold (p = 0.05), and immunization coverage 1.5 fold (p = 0.0005). The number of RI visits to SUS ambulatory care units in 2020 was 4.2 times higher than in preceding years (p = 0.0014), with a peak of 280,898 diagnoses in July 2020.

CONCLUSION

The COVID-19 pandemic appears to have led to a dramatic decline in preventative and treatment services provided by SUS to the Brazilian population. Our findings may aid decision-makers in formulating policies to increase the availability of outpatient services in the aftermath of the pandemic. Counter measures will be critical to avoid a resurgence in vaccine-preventable diseases and complications stemming from non-communicable, chronic health conditions.

Cobertura vacinal infantil de hepatite A, tríplice viral e varicela: análise de tendência temporal em Minas Gerais, Brasil

RESUMO: Objetivo: Analisar a tendência temporal da cobertura vacinal de hepatite A, tríplice viral e varicela em um estado brasileiro no período de 2014 a 2020. Métodos: Estudo ecológico de séries temporais, que considerou dados dos 853 municípios de Minas Gerais que compõem as 14 regiões do estado, sendo estas as unidades territoriais de análise. Foram analisados registros de doses aplicadas das vacinas hepatite A, tríplice viral e varicela registrados no Sistema de Informação de Imunização do Brasil. As tendências foram estimadas pela regressão de Prais-Winsten e calculados os intervalos de confiança 95% das medidas de variação. Resultados: Identificaram-se baixas coberturas vacinais de hepatite A, tríplice viral e varicela. Coberturas acima de 95% foram observadas somente no ano de 2015 para a vacina contra hepatite A (98,8%) e, em 2016, para a varicela (98,4%). A vacina tríplice viral apresentou cobertura inferior a 95% em todos os anos analisados. Uma queda de 13,6 e 4,3% entre os anos de 2019 e 2020 foi identificada para as vacinas tríplice viral e hepatite A, respectivamente. Observou-se tendência decrescente na cobertura vacinal da hepatite A nas regiões Sul (p=0,041), Leste (p=0,030) e Norte (p=0,045); para a tríplice viral, nas regiões Jequitinhonha (p=0,002), Leste (p=0,004) e Norte (p=0,024). A cobertura crescente foi observada somente para a varicela em oito regiões do estado. Conclusões: Os dados apontam heterogeneidade no comportamento temporal das coberturas vacinais em Minas Gerais. A tendência decrescente em algumas regiões desperta preocupação pela possibilidade do recrudescimento de doenças, como o sarampo, até então controladas.

Childhood vaccination coverage of hepatitis A, measles, mumps and rubella, and varicella: temporal trend analysis in Minas Gerais, Brazil

ABSTRACT: Objective: To analyze the temporal trend of vaccination coverage for hepatitis A, measles, mumps and rubella, and varicella in a Brazilian state from 2014 to 2020. Methods: An ecological, time-series study that considered data from 853 municipalities in the state of Minas Gerais that compose the 14 regions of the state, these being the territorial units of analysis. Records of applied doses of hepatitis A, measles, mumps and rubella, and varicella vaccines registered in the Brazilian Immunization Information System were analyzed. Trends were estimated by Prais-Winsten regression and 95% confidence intervals of measures of variation were calculated. Results: Low vaccine coverage of hepatitis A, measles, mumps and rubella, and varicella was identified. Coverages above 95% were observed only in 2015 for the vaccine against hepatitis A (98.8%) and, in 2016, for varicella (98.4%). The measles, mumps and rubella vaccine showed coverage of less than 95% in all analyzed years. Decreases of 13.6 and 4.3% between the years 2019 and 2020 were identified for the measles, mumps and rubella, and hepatitis A vaccines, respectively. There was a decreasing trend in hepatitis A vaccination coverage in the South (p=0.041), East (p=0.030), and North (p=0.045) regions; and for the measles, mumps and rubella in Jequitinhonha Valley (p=0.002), East (p=0.004), and North (p=0.024) regions. Increasing coverage was observed only for varicella in eight regions of the state. Conclusions: The data point to heterogeneity in the temporal behavior of vaccination coverage in Minas Gerais. The downward trend in some regions causes concern about the possibility of resurgence of diseases, such as measles, which until then had been controlled.

One Field Epidemiologist per 200,000 Population: Lessons Learned from Implementing a Global Public Health Workforce Target

The World Health Organization monitoring and evaluation framework for the International Health Regulations (IHR, 2005) describes the targets for the Joint External Evaluation (JEE) indicators. For workforce development, the JEE defines the optimal target for attaining and complying with the IHR (2005) as 1 trained field epidemiologist (or equivalent) per 200,000 population. We explain the derivation and use of the current field epidemiology workforce development target and identify the limitations and lessons learned in applying it to various countries' public health systems. This article also proposes a way forward for improvements and implementation of this workforce development target.

Macroscopic patterns of interacting contagions are indistinguishable from social reinforcement

From fake news to innovative technologies, many contagions spread as complex contagions via a process of social reinforcement, where multiple exposures are distinct from prolonged exposure to a single source.1 Contrarily, biological agents such as Ebola or measles are typically thought to spread as simple contagions.2 Here, we demonstrate that these different spreading mechanisms can have indistinguishable population-level dynamics once multiple contagions interact. In the social context, our results highlight the challenge of identifying and quantifying spreading mechanisms, such as social reinforcement,3 in a world where an innumerable amount of ideas, memes and behaviors interact. In the biological context, this parallel allows the use of complex contagions to effectively quantify the non-trivial interactions of infectious diseases.