Dengue in Rio Grande do Sul, Brazil: 2014 to 2016

Role of air pollutants in dengue fever incidence: evidence from two southern cities in Taiwan

Air pollution may be involved in spreading dengue fever (DF) besides rainfalls and warmer temperatures. While particulate matter (PM), especially those with diameter of 10 μm (PM10) or 2.5 μm or less (PM25), and NO2 increase the risk of coronavirus 2 infection, their roles in triggering DF remain unclear. We explored if air pollution factors predict DF incidence in addition to the classic climate factors. Public databases and DF records of two southern cities in Taiwan were used in regression analyses. Month order, PM10 minimum, PM2.5 minimum, and precipitation days were retained in the enter mode model, and SO2 minimum, O3 maximum, and CO minimum were retained in the stepwise forward mode model in addition to month order, PM10 minimum, PM2.5 minimum, and precipitation days. While PM2.5 minimum showed a negative contribution to the monthly DF incidence, other variables showed the opposite effects. The sustain of month order, PM10 minimum, PM2.5 minimum, and precipitation days in both regression models confirms the role of classic climate factors and illustrates a potential biological role of the air pollutants in the life cycle of mosquito vectors and dengue virus and possibly human immune status. Future DF prevention should concern the contribution of air pollution besides the classic climate factors.

Epidemiological profile of arboviruses in two different scenarios: dengue circulation vs. dengue, chikungunya and Zika co-circulation

BACKGROUND

The severity and distribution of dengue virus (DENV) infections have been attributed to a complex interaction among viral, host and environmental factors. Herein, we investigated the influence of chikungunya (CHIKV) and Zika (ZIKV) viruses on the epidemiological profile of dengue cases, using Recife, Pernambuco state, Brazil, as a study model. In addition, we described and compared the epidemiological profile related to each arbovirus (DENV vs. CHIKV vs. ZIKV).

METHODS

All cases of dengue, chikungunya and Zika reported to the Pernambuco Health Department in 2011-2013 (DENV circulation) and 2016-2018 (DENV, CHIKV and ZIKV co-circulation) were included in our study. The cases were classified by sex, age and race/color and their distribution was analyzed by the χ² test. Furthermore, the data were also analyzed for co-infections. Temperature, humidity and rainfall data were analyzed using one-way ANOVA and paired t-test.

RESULTS

During 2011-2013, 15,315 dengue cases were diagnosed, most of them female, brown and 20-29 age group. Between 2016 and 2018, 15,870 dengue cases were described, which presented the same profile described above. In the two triennia, the female/male dengue ratio fluctuated significantly, ranging from 1.07 to 1.52. Regarding chikungunya, 7076 cases were reported, most of them female and brown. The female/male ratio also fluctuated significantly, ranging from 1.62 to 2.1. Two main age groups were observed in chikungunya: ≤ 19 years (minority of diagnoses) and ≥ 20 years (majority of diagnoses). In the same triennium, 266 Zika cases were reported to the Pernambuco Health Department, mainly in females and in the 0-9 and 20-39 age groups. In general, 119 co-infections were identified: 117 DENV-CHIKV, 1 CHIKV-ZIKV and 1 DENV-CHIKV-ZIKV. Concerning climate data, only the humidity in 2011 was significantly different from the other years.

CONCLUSION

The epidemiological profile of dengue cases did not change after the introduction of CHIKV and ZIKV. Females were the most diagnosed with dengue, chikungunya or Zika, however we found important differences in the age profile of these arboviruses, which should be considered by public health policies, as well as investigated in future studies of virus-host interaction.

Dengue, chikungunya, and Zika virus infections in Latin America and the Caribbean: a systematic review

Objectives

To characterize the distribution profile of dengue, chikungunya, and Zika virus infections in Latin America and the Caribbean and to identify possible factors associated with the risk of dissemination and severity of these arboviruses.

Methods

The protocol of this review was registered on the PROSPERO platform. Searches were carried out in the following databases: Virtual Health Library, MEDLINE/PubMed, and Embase. The search terms were: Zika virus, Zika virus infection, dengue, dengue virus, chikungunya virus, chikungunya fever, epidemiology, observational study, Latin America, and Caribbean region. Studies that addressed the distribution of these arboviruses and the risk factors associated with dengue, Zika virus disease, and chikungunya, published between January 2000 and August 2020 in English, Portuguese, and Spanish, were included.

Results

Of 95 studies included, 70 identified risk factors, clinical manifestations, and outcomes for arbovirus infections and 25 described complications and/or deaths. The highest frequency of confirmed cases was for dengue. Brazil reported most cases of the three arboviruses in the period analyzed. Environmental and socioeconomic factors facilitated the proliferation and adaptation of vectors, and host-related factors were reported to aggravate dengue. Most deaths were due to chikungunya, Zika virus disease caused most neurological alterations, and dengue resulted in greater morbidity leading to more frequent hospitalization.

Conclusions

The review provides a broad view of the three arboviruses and the intrinsic aspects of infections, and highlights the factors that influence the spread of these viruses in the populations studied.

Arbovirus, herpesvirus, and enterovirus associated with neurological syndromes in adult patients of a university hospital, 2017-2018

INTRODUCTION:

Herpesviruses, enteroviruses, and arboviruses are important because of their clinical relevance and ability to cause meningitis, encephalitis, meningoencephalitis, and other diseases. The clinical virology associated with diagnostic technologies can reduce the morbidity and mortality of such neurological manifestations. Here we aimed to identify the genomes of agents that cause neurological syndromes in cerebrospinal fluid (CSF) samples from patients with suspected nervous system infections admitted to the University Hospital of the University of Campinas, São Paulo, Brazil, in 2017-2018.

METHODS:

CSF samples collected from adult patients with neurological syndrome symptoms and negative CSF culture results were analyzed using polymerase chain reaction (PCR), reverse transcriptase-PCR, and real-time PCR, and their results were compared with their clinical symptoms. One CSF sample was obtained from each patient.

RESULTS:

Viral genomes were detected in 148/420 (35.2%) CSF samples: one of 148 (0.2%) was positive for herpes simplex virus-1; two (0.5%) for herpes simplex virus-2; eight (1.9%) for varicella-zoster virus; four (1%) for Epstein-Barr virus; one (0.2%) for cytomegalovirus; 32 (7.6%) for human herpesvirus-6; 30 (7.1%) for non-polio enterovirus; 67 (16.0%) for dengue virus, three (0.7%) for yellow fever virus, and 21 (5%) for Zika virus.

CONCLUSIONS:

The viral genomes were found in 35.2% of all analyzed samples, showing the high prevalence of viruses in the nervous system and the importance of using a nucleic acid amplification test to detect viral agents in CSF samples.

Assessment of the global circulation and endemicity of dengue

Dengue is a significant public health issue, affecting hundreds of millions of people worldwide. As it is spreading from tropical and subtropical zones, some regions previously recognised as non-endemic are at risk of becoming endemic. However, the global circulation of dengue is not fully understood and quantitative measurements of endemicity levels are lacking, posing an obstacle in the precise control of dengue spread. In this study, a sequence-based pipeline was designed based on random sampling to study the transmission of dengue. The limited intercontinental transmission was identified, while regional circulation of dengue was quantified in terms of importation, local circulation and exportation. Additionally, hypo- and hyper-endemic regions were identified using a new metric, with the former characterised by low local circulation and increased importation, whereas the latter by high local circulation and reduced importation. In this study, the global circulation pattern of dengue was examined and a sequence-based endemicity measurement was proposed, which will be helpful for future surveillance and targeted control of dengue.

Dynamic mapping of the probability of infestation by urban arbovirus vectors in the municipalities of Rio Grande do Sul state, Brazil, 2016-2017

OBJECTIVE

To compare official mapping with probabilistic mapping of infestation by Aedes spp. in the municipalities of Rio Grande do Sul state, Brazil.

METHODS

This was an ecological study using data from samples of mosquito breeding sites collected in 2016-2017; official classification was obtained from epidemiological reports, and infestation per municipality and week was estimated by fitting a dynamic site-occupancy model to data from municipal epidemiological surveillance.

RESULTS

187,245 samples collected in 473 municipalities returned 10,648 detections of Aedes aegypti, and 8,414 detections of Aedes albopictus; official mapping agrees with probabilistic mapping in municipalities in the northwestern and western regions of the state. The mappings are not in agreement in the eastern, central, northeastern and southern regions, revealing municipalities officially not infested but with high probability of infestation and notification of arbovirus infection.

CONCLUSION

While official classification identified critically infested municipalities in the state's northwestern and western regions, it did not identify infestation in municipalities with possible false zero errors and where infestation varies over time.

Control and prevention of infectious diseases from a One Health perspective

The ongoing COVID-19 pandemic has caught the attention of the global community and rekindled the debate about our ability to prevent and manage outbreaks, epidemics, and pandemics. Many alternatives are suggested to address these urgent issues. Some of them are quite interesting, but with little practical application in the short or medium term. To realistically control infectious diseases, human, animal, and environmental factors need to be considered together, based on the One Health perspective. In this article, we highlight the most effective initiatives for the control and prevention of infectious diseases: vaccination; environmental sanitation; vector control; social programs that encourage a reduction in the population growth; control of urbanization; safe sex stimulation; testing; treatment of sexually and vertically transmitted infections; promotion of personal hygiene practices; food safety and proper nutrition; reduction of the human contact with wildlife and livestock; reduction of social inequalities; infectious disease surveillance; and biodiversity preservation. Subsequently, this article highlights the impacts of human genetics on susceptibility to infections and disease progression, using the SARS-CoV-2 infection as a study model. Finally, actions focused on mitigation of outbreaks and epidemics and the importance of conservation of ecosystems and translational ecology as public health strategies are also discussed.

Retrospective cross-sectional observational study on the epidemiological profile of dengue cases in Pernambuco state, Brazil, between 2015 and 2017

BACKGROUND

The spread of Dengue virus (DENV) infections, as well as their signs and symptoms, are the result of a complex interaction between several factors. In Brazil, especially in the Northeastern, dengue is an important public health problem. Here, we report an epidemiological analysis of dengue cases in Pernambuco state, Northeastern Brazil, during 2015-2017.

METHODS

This work is a retrospective cross-sectional observational study on the epidemiological profile of all dengue cases confirmed and reported to the Health Secretary of Pernambuco between 2015 and 2017. These data cover all municipalities of Pernambuco, except Fernando de Noronha. DENV-positive individuals were classified according to the dengue type (without and with warning signs, or severe dengue), age, gender, ethnicity and intermediate geographic region of residence (Recife, Caruaru, Serra Talhada or Petrolina). The distribution of cases over the years was assessed by χ2 test. Temperature and rainfall data were evaluated by Unpaired t-test. p-value < 0.05 and CI 95% were considered in all analyses.

RESULTS

Most dengue cases was without warning signs. The most observed characteristics in the less severe dengue phenotypes were: female, mulatto ethnicity and age between 20 and 39 years old; this profile was more clearly observed in 2015. In 2016 and 2017, however, the numbers of dengue without and with warning signs were more evenly distributed and the difference in cases within groups decreased significantly. Regarding severe dengue, mulattoes were the most affected, but it is possible to note a trend towards a more uniform distribution between the genders and ages. Recife was the region with the highest numbers of both total cases and incidence rates and the highest rainfall levels. Overall, over the years, there has been a decrease in dengue cases in all regions of Pernambuco.

CONCLUSIONS

We identified the epidemiological profile of dengue in Pernambuco, Brazil, reporting the gender, age, ethnicity and regions most affected by different dengue types. In addition, we observed that these cases were probably more influenced by rainfall than by temperature. Finally, we believe that this epidemiological knowledge is important to direct public health policies to the reality of each population.

Prevalence of self-reported dengue infections in Manaus Metropolitan Region: a cross-sectional study

INTRODUCTION

Dengue is an endemic and epidemic disease in Brazil, with a high burden of disease. Amazonas State has a high risk of transmission. This study aimed to assess the self-reported prevalence of dengue in adults living in Manaus Metropolitan Region.

METHODS

A cross-sectional study was conducted with adults living in Manaus Metropolitan Region in 2015. We performed a three-phase probabilistic sampling to collect participants' clinical and sociodemographic data. Self-reported dengue infection in the previous year was the primary outcome. Descriptive statistics and Poisson regression analysis with robust variance were used to calculate the prevalence ratio (PR) of dengue infections with 95% confidence intervals (95% CIs). Multilevel analysis including city and neighborhood variables was calculated. All analyses considered the complex sampling.

RESULTS

Among the 4,001 participants, dengue in the previous year was self-reported by 7.0% (95% CI 6.3%-7.8%). Dengue was more frequent in women(PR 1.51; 95% CI 1.06-2.13), elderly participants (≥60 years old, PR 2.54; 95% CI 1.19-5.45), White and Asian participants (PR, 1.57; 95% CI, 1.11-2.23), and individuals who had not received endemic agent visits (PR, 2.28; 95% CI, 1.31-3.99). After multilevel analysis, sex was no longer a significant variable, with the remaining associations still significant.

CONCLUSIONS

Seven out of 100 inhabitants of Manaus Metropolitan Region reported dengue in the previous year. Dengue was predominantly observed in women, elderly individuals, White and Asian individuals, and individuals who did not receive endemic agent visits. The setting plays an important role in dengue infections.