SARS CoV-2 infection among Healthcare Workers from different public health units in Brazil

Understanding COVID-19 exposure differences among Healthcare Workers (HCWs) across various healthcare units is crucial for their protection and effective management of future outbreaks. However, comparative data on COVID-19 among HCWs in different healthcare units are scarce in Brazil. This study evaluated the relationship between SARS-CoV-2 infection and workplaces in HCWs from three distinct healthcare settings in Brazil. It also examined COVID-19 symptom dynamics reported by them. The cohort comprised 464 HCWs vaccinated with two doses of CoronaVac and a BNT162b2 booster from different institutions: Primary Health Care Units (PHCUs), Emergency Care Units (ECUs), and Hospitals. Participants answered a questionnaire and underwent blood collection at various time points after vaccinations. RT-PCR data and post-vaccination antibody responses were utilized as indicators of SARS-CoV-2 infection. We found that most infected HCWs worked in ECUs, where positive RT-PCR percentages were higher compared to PHCUs and Hospitals. ECUs also showed the highest seropositivity and antibody levels, especially after the first CoronaVac dose. The second dose of CoronaVac diminished the differences in the antibody levels among HCWs from ECUS, PHCUs, and Hospitals, indicating the benefit of the second dose to equalize the antibody levels between previously exposed and unexposed persons. Moreover, COVID-19 symptoms appeared to evolve over time.

Influence of age, gender, previous SARS-CoV-2 infection, and pre-existing diseases in antibody response after COVID-19 vaccination: A review

Vaccines induce specific long-term immunological memory against pathogens, preventing the worsening of diseases. The COVID-19 health emergency has caused more than 6 million deaths and started a race for vaccine development. Antibody response to COVID-19 vaccines has been investigated primarily in healthcare workers. The heterogeneity of immune responses and the behavior of this response in particular groups were still very little explored. In this review, we discuss whether antibody responses after vaccination are influenced by age, gender, previous SARS-CoV-2 infection, or pre-existing diseases.

Antibody response 6 months after the booster dose of Pfizer in previous recipients of CoronaVac

The most widely used vaccines were messenger RNA (mRNA), viral vector, and inactivated virus with two-dose schedules. In Brazil, the CoronaVac (Sinovac) was the first vaccine approved for emergency use, and the third dose was administered, preferably, with the BNT162b2 vaccine. We evaluated antibody levels after 6 months of the booster dose with BNT162B2 in previous recipients of CoronaVac and whether a subsequent severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection enhances the antibody response. We analyze the humoral response (spike [S] IgM for the SARS-CoV-2 and IgG for the S and nucleocapsid [N] proteins) in samples collected before the third dose and 6 months after the third dose. The presence of antibodies was measured by using Abbott Architect i2000SR. The IgM and IgG antispikes were stimulated mainly 30 days after the third dose (30d/3D), with a decline over time. The IgG anti-N was stimulated predominantly in 90d/3D and 180d/3D. The N IgG levels were 50 and 35 times higher in the positive polymerase chain reaction (PCR) group in 90d/3D and 180d/3D, respectively. The S IgG titers were 1.5 times elevated in the positive PCR group, in 180d/3D. The BNT162b2 boosted the S IgG levels, decreasing after 60 days. The booster shot induced IgM and IgG antibodies against spike protein. Infection after vaccination increased antibodies against protein N.

Persistently positive SARS-CoV-2 specific IgM during one-year follow-up

IgM antibodies typically appear in the early stage of infection and have a short maintenance time, so IgM is frequently used as a diagnostic criterion for acute or recent disease [1]. However, unconventional IgM specific responses have been described in SARS-COV-2 infection, raising doubts about the use of IgM as a biomarker for COVID-19 and the role of this antibody in immunity to SARS-CoV-2 [1,2]. This article is protected by copyright. All rights reserved.

Seroprevalence and factors associated with SARS-CoV-2 infection among education workers after the first wave: the first cross-sectional study in Brazil

BACKGROUND

The school community was heavily impacted by the Covid-19 pandemic, especially with the long time of school closures. This study aimed to analyze the seroprevalence of SARS-CoV-2 antibodies and possible factors associated with seropositivity for COVID-19 in teachers and other school staff, and to estimate the fraction of asymptomatic individuals by sex and age group.

METHODS

We conducted a serological survey of SARS-CoV-2 infections. An analytical cross-sectional study was conducted in Fortaleza, Brazil. Teachers and other staff members from pre-schools to universities of higher education to were investigated.

RESULTS

A total of 1,901 professionals participated in the study, of which 1,021 were staff and 880 were teachers. The seroprevalence of SARS-CoV-2 was 8.0% (152/1901). In the seropositive group, 48.3% were asymptomatic. There was a predominance of women (68.4%); and, 47.1% of the participants were between 31 and 45 years old. There was an increase in prevalence with increasing age. An inverse relationship was found for education level: more professionals with less education tested positive for COVID-19. The presence of an infected person living in the same household was significantly associated with positive results for COVID-19 among the professionals.

CONCLUSIONS

This is the first study to report the seroprevalence of IgG against SARS-CoV-2 in Brazilian educational staff after the first wave of the disease. In this study, the seroprevalence was much lower than that in the general population. During school reopening, a small fraction of school workers showed serologically detectable signs of SARS-CoV-2 exposure.

Dynamics of SARS-CoV-2 Antibody Response to CoronaVac followed by Booster Dose of BNT162b2 Vaccine

We evaluated the longitudinal dynamics of antibody response to the SARS-CoV-2 vaccine CoronaVac and the effect of a booster dose of BNT162b2 vaccine. We found a robust antibody response after the second dose of CoronaVac that wanes over time. The response was recovered by BNT162b2, which boosted anti-spike antibody titers.

Chikungunya Death Risk Factors in Brazil, in 2017: A case-control study

Background

In 2016/2017 we had a major epidemic of chikungunya (CHIK) in Brazil, with many deaths. We evaluated to factors associated with deaths from CHIK that occurred in the city of Fortaleza, Brazil.

Methods

A matched case-control study was conducted (1:2), by sex, age (± 5 years) and neighborhood. Cases were CHIK deaths that occurred between January 1 and December 31, 2017, in Fortaleza, Brazil, and which were laboratory confirmed. Controls were laboratory confirmed CHIK patients occurring in the same neighborhood and in the same period, but which did not progress to death.

Results

82 cases of CHIK and 164 controls were included. Considering the clinical history, significant associations were found between other chronic heart diseases (OR 3.8; CI: 1.53–9.26) and chronic kidney disease (OR 12.77; CI: 2.75–59.4). In the multivariate analysis of the variables related to signs and symptoms, fever (OR: 19.23 CI: 1.73–213.78), abdominal pain (OR: 3; 74 CI: 1.06–13.16), apathy (OR: 11.62 CI: 2.95–45.82) and dyspnea (OR: 50.61; CI: 12.37–207.18) were identified with greater likelihood of death from CHIK. It also stood out that altered blood glucose was associated with cases with a worse prognosis (OR: 13.5; CI: 1.3–135.0). Among the laboratory findings, only lymphocytes and albumin were not associated with greater likelihood of death.

Conclusion

The factors related with deaths were chronic kidney disease and previous heart disease, presence of fever, abdominal pain, apathy, dyspnea and arthritis and laboratory findings such as leukocytosis, leukopenia, thrombocytopenia, neutropenia and lymphopenia.

Dynamics of antibody response to CoronaVac vaccine

CoronaVac was the first vaccine approved in Brazil for use in healthcare workers (HCWs). However, there is limited information about it, with little long‐term evidence on post‐vaccination antibody persistence. This study evaluated the antibody response to SARS‐CoV‐2 in 1237 HCWs after the first (1D), second dose (2D), and 6 months postvaccination (6mA2D) with CoronaVac. The seropositivity was 88% at 1D, increasing to 99.8% at 2D, but decreasing to 97.9% at 6mA2D, which was also observed at the analyzed antibody levels. Interestingly, the levels in females were higher than males, and we found a positive correlation with previous SARS‐CoV‐2 infection. Participants with comorbidities had lower levels suggesting the need to monitor for a potential booster dose. Our findings suggest that CoronaVac induced a robust antibody response that wanes significantly over time. Further longitudinal studies are needed to identify whether the antibodies will decline or plateau at a lower level.

Our findings suggest that CoronaVac induced a robust antibody response that wanes significantly over time.

In our study, two doses of CoronaVac were capable of induction an antibody response in people ≥51 years old.

The seropositivity and the levels of antibodies were higher in females when compared to males.

We found a positive correlation with previous SARS‐CoV‐2 infection, previously infected participants had a significantly higher antibody response than previously uninfected participants.

Our findings suggest that patients with chronic diseases may need a booster shot of CoronaVac vaccine.

Individuals with immune‐mediated diseases developed a significant humoral response following the administration of two doses of CoronaVac, albeit with lower antibody titers.

A wide spectrum of neurological manifestations in pediatrics patients with the COVID-19 infection: a case series

Neurological symptoms in COVID-19 patients can also be found in the pediatric population, but they are usually described as mild symptoms. Herein, we described a case series of four pediatric patients with severe and highly heterogeneous central and peripheral nervous system manifestations. The objective was to report neurological manifestations of COVID-19 in children and adolescents. The design is case series. The participants are four children and adolescents with confirmed COVID-19. The main outcome and measures are as follows: Clinical data were gathered from electronic medical records, and data of all neurologic symptoms were checked by a trained neurologist. We reported four pediatric patients with COVID-19 and different neurologic symptoms. Case 1 was a 16-year-old girl with a sensory and motor polyradiculopathy with RT-qPCR for COVID-19 and dengue both detected in CSF that improved after appropriate treatment. Case 2 was a 15-year-old boy with Guillain-Barre syndrome and had good response after using human immunoglobulin. Case 3 was a 5-year-old girl with acute intracranial hypertension that improved after going through lumbar puncture and using acetazolamide. Case 4 was a 2-month-old male infant with focal epileptic seizures that recovered after antiepileptic treatment. We highlight the need to consider different neurologic manifestations as part of the COVID-19 clinical spectrum.

West Nile Virus in the State of Ceará, Northeast Brazil

In June 2019, a horse with neurological disorder was diagnosed with West Nile virus (WNV) in Boa Viagem, a municipality in the state of Ceará, northeast Brazil. A multi-institutional task force coordinated by the Brazilian Ministry of Health was deployed to the area for case investigation. A total of 513 biological samples from 78 humans, 157 domestic animals and 278 free-ranging wild birds, as well as 853 adult mosquitoes of 22 species were tested for WNV by highly specific serological and/or molecular tests. No active circulation of WNV was detected in vertebrates or mosquitoes by molecular methods. Previous exposure to WNV was confirmed by seroconversion in domestic birds and by the detection of specific neutralizing antibodies in 44% (11/25) of equids, 20.9% (14/67) of domestic birds, 4.7% (13/278) of free-ranging wild birds, 2.6% (2/78) of humans, and 1.5% (1/65) of small ruminants. Results indicate that not only equines but also humans and different species of domestic animals and wild birds were locally exposed to WNV. The detection of neutralizing antibodies for WNV in free-ranging individuals of abundant passerine species suggests that birds commonly found in the region may have been involved as amplifying hosts in local transmission cycles of WNV.

Seroprevalence, spatial dispersion and factors associated with flavivirus and chikungunha infection in a risk area: a population-based seroprevalence study in Brazil

BACKGROUND

The State of Ceará, in Northeastern Brazil, suffers from a triple burden of arboviruses (dengue, Zika and chikungunya). We measured the seroprevalence of chikungunya, dengue and Zika and its associated factors in the population of Juazeiro do Norte, Southern Ceará State, Brazil.

METHODS

A cross-sectional study of analytical and spatial analysis was performed to estimate the seroprevalence of dengue, Zika and chikungunya, in the year 2018. Participants were tested for IgM and IgG against these three viruses. Those with IgM and/or IgG positive tests results were considered positive. Poisson regression was used to analyze the factors associated with positive cases, in the same way that the spatial analysis of positive cases was performed to verify whether the cases were grouped.

RESULTS

Of the 404 participants, 25.0% (103/404) were positive for CHIKV, 92.0% (373/404) for flavivirus (dengue or Zika) and of these, 37.9% (153/404) samples were classified as probable dengue infection. Of those who reported having had an arbovirus in the past, positive CHIKV cases had 58.7% arthralgia (PR = 4.31; 95% CI: 2.06-9.03; p = 0.000) mainly in the hands, ankles and feet. Age over 60 years had a positive association with cases of flavivirus (PR = 1.29; 95% CI: 1.09-1.54; p = 0.000). Fever, muscle pain, joint pain and skin rash were the most reported symptoms (46.1, 41.0, 38.3 and 28.41%, respectively). The positive cases of chikungunya and dengue or Zika were grouped in space and the city center was most affected area.

CONCLUSIONS

Four years after the introduction of CHIKV, where DENV has been in circulation for over 30 years, 1/4 of the population has already been exposed, showing the extent of the epidemic. The measured prevalence was much higher than that reported by local epidemiological surveillance.

Experience of the Arbovirus Death Investigation Committee in Ceará, Brazil, in 2017: advances and challenges

OBJECTIVE

to describe the experience and preliminary results of the Arbovirus Death Investigation Committee in Ceará, Brazil, in 2017.

METHODS

the Committee investigates and discusses all suspected cases of arbovirus deaths reported by the epidemiological surveillance service.

RESULTS

a total of 443 suspected arbovirus deaths were reported, 220 (49.7%) of which were confirmed; of these, 88.2% were from chikungunya and 11.8% from dengue; the median age of chikungunya deaths was higher when compared to dengue (77 versus 56 years) and the time until death was also longer when compared to dengue (38 versus 12 days); median time for case closure was 54.5 days; in 2017, Ceará confirmed 80.4% of Brazilian chikungunya deaths.

CONCLUSION

the investigation of deaths showed that CHIK viruses were responsible for the majority of arboviral deaths in the state of Ceará, in 2017.

Dengue 4 in Ceará, Brazil: characterisation of epidemiological and laboratorial aspects and causes of death during the first epidemic in the state

BACKGROUND The first dengue cases in Brazil with laboratory confirmation occurred in the northern region of the country, with the isolation of two serotypes, dengue virus 1 (DENV-1) and DENV-4. In Ceará, the introduction of DENV-4 was reported during a DENV-1 epidemic in 2011, with only two isolations. OBJECTIVES The aim of this study was to characterise the first DENV-4 epidemic in the state of Ceará, Brazil. METHODS The study population was composed of patients with suspected dengue that were reported to health care units from January to December 2012. The laboratory confirmation of infection was made by viral isolation, reverse transcription polymerase chain reaction (RT-PCR), AgNS1, immunohistochemistry and IgM enzyme-linked immunosorbent assay (ELISA). MAIN CONCLUSIONS In the study year, 72,211 suspected dengue cases were reported and 51,865 of these cases (71.8%) were confirmed to be positive. Co-circulation of three serotypes, DENV-1, DENV-3 and DENV-4, was detected with a predominance of DENV-4 (95.3%). Most cases were not severe, but there were 44 fatal outcomes. DENV-4 Genotype II was identified for the first time in Ceará.

Maternal and infant death after probable vertical transmission of chikungunya virus in Brazil - case report

BACKGROUND

Chikungunya virus infection in neonates is relatively rare and can lead to death.

CASE PRESENTATION

We report the occurrence of the first death of a mother and child after probable vertical transmission of chikungunya virus in Brazil. A 28-year-old pregnant woman with hypertension presented with symptoms compatible with an arboviral disease at 34 weeks' gestation. She developed preeclampsia with severe respiratory failure which resulted in the emergency cesarean section, and the patient died 12 days after the onset of symptoms. The pre-term newborn weighed 2535 g, with an Apgar score of 4/8. He was referred to the neonatal ICU with neutrophilia and thrombocytopenia, several seizure episodes, and hemorrhagic disorders, which resulted in death. Chikungunya IgM antibody was detected in the cerebrospinal fluid.

CONCLUSIONS

We present the first documented maternal and neonatal death in Brazil after probable chikungunya infection during pregnancy.

Entomological and epidemiological aspects of dengue epidemics in Fortaleza, Ceará, Brazil, 2001-2012

OBJECTIVE

to characterize the entomological and epidemiological aspects of dengue epidemics occurred in Fortaleza, Ceará, Brazil, from 2001 to 2012.

METHODS

descriptive study with data from the Information System for Notifiable Diseases (Sinan), Information System of Hospitalizations due to Yellow Fever and Dengue (2001-2009), National Program for Dengue Control (2010-2012), and Rapid Survey of Aedes aegypti Infestation Index, referring to the years in which the incidence of dengue was above 75%.

RESULTS

from 2001 to 2012, 194,446 cases of suspected dengue were notified; the epidemic years were 2001, 2006, 2008, 2011 and 2012; there was a progressive increase in the incidence of the disease (587.0/100 thousand inhabitants in 2001 and 1,561.1/100 inhabitants in 2012); there was co-circulation of up to three serotypes and high vector infestation, especially in water tanks.

CONCLUSION

after a long period of virus circulation in Fortaleza, dengue remains as an important health issue, with severe cases and high fatality rate.

Trinta anos de dengue no Ceará: história, contribuições para ciência e desafios no cenário atual com tripla circulação de arbovírus

Introdução: Embora os primeiros casos de dengue no estado do Ceará tenham ocorrido em 1986, há registros da presença do mosquito Aedes aegypti desde os anos de 1851/1852. Mesmo após 30 anos, a dengue permanece como um problema grave de saúde pública com epidemias cada vez mais frequentes. Objetivo: Resgatar, reunir e sintetizar a evidência científica produzida nos primeiros 30 anos de dengue no Ceará, contribuindo para melhorar sua compreensão e as intervenções de vigilância e controle. Métodos: Realizou-se uma revisão de literatura com busca de artigos (inglês, português e espanhol) nas bases de dados Pubmed, Scielo, Clinicalkey, Lilacs, Google Acadêmico e banco virtual de teses e dissertações da CAPES, além de livros. O período de 1986 a 2016 foi usado como limite de busca e a mesma foi realizada entre os meses de agosto a novembro de 2016. Utilizaram-se os descritores controlados: dengue, Ceará, Fortaleza e Aedes; com interposição do operador boleano “AND”. Resultados: Foram identificadas 574 publicações potencialmente elegíveis, sendo 461 artigos e 113 dissertações ou teses. Foram retirados 272 artigos duplicados ou que não atenderam aos critérios de inclusão. Foram lidos 114 artigos publicados em 60 revistas diferentes, sendo 72,8% artigos completos, 75,2% em inglês, 42,2% experimentais e 81,5% com abordagem quantitativa. Foi publicado apenas um artigo na década de 1980, já na década seguinte foram sete, número que cresceu bastante nos anos 2000, com 38 artigos. No entanto, já há 69 artigos publicados apenas na primeira metade da década de 2010. No período, o Ceará confirmou quase um milhão de casos de dengue, com a circulação dos quatro sorotipos (DENV1 - 1986, DENV2 - 1994, DENV3 - 2002 e DENV4 - 2011) e registrou pelo menos 14 epidemias. A partir de 2015, o Ceará passou a apresentar um cenário diferenciado de tripla epidemia, com a cocirculação autóctone de dois outros arbovírus: Chikungunya e Zika. Conclusão: Nesse período de 30 anos (1986-2016), o Ceará vivenciou várias epidemias de dengue, e, de certa forma, isto vem impulsionando a busca por respostas para o controle desta doença. Há claramente um crescimento em número de artigos publicados a cada ano, revelando a pujança dos grupos locais, que contribuiu de forma importante para a produção científica em diversos fatores relacionados à compreensão da epidemiologia e controle da dengue.

Microcephaly in Infants, Ceará State, Brazil, 2015-2016

In late 2015, the Brazilian Ministry of Health officially announced the association between microcephaly in infants and Zika virus infection of the mother during pregnancy. We describe preliminary findings of this outbreak in Ceará, Northeast Brazil and it’s clinical characteristics in each medical speciality. We report epidemiological findings of 317 cases of microcephaly outbreak potentially associated with ZIKV infection in Ceara, State, Brazil. From mid-2015 to the end of June of 2016, a total of 417 cases of microcephaly were suspected, with 317 confirmed. Among those reported cases, 83.2% (347/417) were detected in the postpartum. Rash during pregnancy was reported by (29.6%) of pregnant women, most commonly in the 1st trimester (18.4%).  The proportion of microcephaly cases increased from less than 1% to 25.8% of the registered cases of genetic abnormalities. The prevalence increased from 0.06/1000 live births in 2010 to 0.56 in 2015 and to 3.22 in January and February of 2016. In addition to microcephaly other associated malformations were detected, such as arthrogryposis, hyperexcitability, irritability with strong and frequent crying. The microcephaly phenotype caused by the zika virus is different from other congenital conditions. The infection in the prenatal period is a new teratogen reported. There is a predominance of neurological impairment, in which neuroimaging plays a crucial role in confirming the clinical suspicion of Congenital Zika Syndrome.

Coinfection with influenza A(H1N1)pdm09 and dengue virus in fatal cases

We report on four patients with fatal influenza A(H1N1)pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses' epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4). Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998). As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015). In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm), caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010). In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013). The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1)pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013). The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1)pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.

Evaluation of the World Health Organization 2009 classification of dengue severity in autopsied individuals, during the epidemics of 2011 and 2012 in Brazil

INTRODUCTION

The dengue classification proposed by the World Health Organization (WHO) in 2009 is considered more sensitive than the classification proposed by the WHO in 1997. However, no study has assessed the ability of the WHO 2009 classification to identify dengue deaths among autopsied individuals suspected of having dengue. In the present study, we evaluated the ability of the WHO 2009 classification to identify dengue deaths among autopsied individuals suspected of having dengue in Northeast Brazil, where the disease is endemic.

METHODS

This retrospective study included 121 autopsied individuals suspected of having dengue in Northeast Brazil during the epidemics of 2011 and 2012. All the autopsied individuals included in this study were confirmed to have dengue based on the findings of laboratory examinations.

RESULTS

The median age of the autopsied individuals was 34 years (range, 1 month to 93 years), and 54.5% of the individuals were males. According to the WHO 1997 classification, 9.1% (11/121) of the cases were classified as dengue hemorrhagic fever (DHF) and 3.3% (4/121) as dengue shock syndrome. The remaining 87.6% (106/121) of the cases were classified as dengue with complications. According to the 2009 classification, 100% (121/121) of the cases were classified as severe dengue. The absence of plasma leakage (58.5%) and platelet counts <100,000/mm3 (47.2%) were the most frequent reasons for the inability to classify cases as DHF.

CONCLUSIONS

The WHO 2009 classification is more sensitive than the WHO 1997 classification for identifying dengue deaths among autopsied individuals suspected of having dengue.

Postmortem Diagnosis of Dengue as an Epidemiological Surveillance Tool

Dengue remains a problem in Brazil, and a substantial number of cases that progress to death are not diagnosed by health services. We evaluated the impact of a protocol adopted by the Coroner's Office Rocha Furtado (CO-RF) for the detection of unreported deaths from dengue in Brazil. We evaluated prospectively cases of deaths referred to the CO-RF with suspicion of dengue and those referred with other diagnosis in which the pathologists suspected dengue as the cause of death. Biological material was collected from all bodies autopsied, for which the suspected cause of death was dengue, between January 2011 and December 2012. Of the 214 bodies autopsied, 134 (62.6%) tested positive for dengue; of these cases, 121 were classified as dengue according to the World Health Organization's case definition (1997 or 2009, as appropriate). Thus, CO-RF detected 90 deaths from dengue, which were not suspected during disease progression. This CO-RF protocol, through a combined effort of the surveillance and laboratory teams, increased the detection of fatal dengue cases by 5-fold. This is the largest series of autopsies performed in cases of death related to dengue in the world to date.

Death by dengue fever in a Brazilian child: a case report

Background

Dengue is an important worldwide public health problem, and continues to spread in Brazil. This article presents the first Brazilian case report of the death of an indigenous child by dengue fever.

Case presentation

In August 2013, a child aged 2 years and from the Tremembé ethnic group, who was previously healthy with no complaints, suddenly presented intense crying, precordial pain, and general malaise. A few minutes after these non-specific symptoms, the patient started tonic–clonic convulsions and had cyanosis, a substantial increase in body temperature to the touch, cold sudoresis, sphincter relaxation, and unconsciousness. This situation remained for 15 minutes, progressing to respiratory insufficiency, with consequent absence of peripheral pulses. Death was confirmed approximately 40 minutes after the first symptoms. An autopsy was performed using the usual techniques. Immunohistochemistry was positive for dengue, and microscopic examination indicated micro perivascular edema and cerebral hemorrhage.

Conclusion

Considering that the death occurred during the major endemic seasonal period for dengue fever, primary clinical evidence suggestive of viral infection presenting with sudden and quick death, and positive immunohistochemistry results, the case was closed as severe dengue fever. Clinicians must consider dengue as a diagnostic hypothesis among the indigenous population in Brazil.

Occurrence of natural vertical transmission of dengue-2 and dengue-3 viruses in Aedes aegypti and Aedes albopictus in Fortaleza, Ceará, Brazil

BACKGROUND

Aedes aegypti and Aedes albopictus perform an important role in the transmission of the dengue virus to human populations, particularly in the tropical and subtropical regions of the world. Despite a lack of understanding in relation to the maintenance of the dengue virus in nature during interepidemic periods, the vertical transmission of the dengue virus in populations of A. aegypti and A. albopictus appears to be of significance in relation to the urban scenario of Fortaleza.

METHODS

From March 2007 to July 2009 collections of larvae and pupae of Aedes spp were carried out in 40 neighborhoods of Fortaleza. The collections yielded 3,417 (91%) A. aegypti mosquitoes and 336 (9%) A. albopictus mosquitoes. Only pools containing females, randomly chosen, were submitted to the following tests indirect immunofluorescence (virus isolation), RT-PCR/nested-PCR and nucleotide sequencing at the C-prM junction of the dengue virus genome.

RESULTS

The tests on pool 34 (35 A. albopictus mosquitoes) revealed with presence of DENV-3, pool 35 (50 A. aegypti mosquitoes) was found to be infected with DENV-2, while pool 49 (41 A. albopictus mosquitoes) revealed the simultaneous presence of DENV-2 and DENV-3. Based on the results obtained, there was a minimum infection rate of 0.5 for A. aegypti and 9.4 for A. albopictus. The fragments of 192 bp and 152 bp related to DENV-3, obtained from pools 34 and 49, was registered in GenBank with the access codes HM130699 and JF261696, respectively.

CONCLUSIONS

This study recorded the first natural evidence of the vertical transmission of the dengue virus in populations of A. aegypti and A. albopictus collected in Fortaleza, Ceará State, Brazil, opening a discuss on the epidemiological significance of this mechanism of viral transmission in the local scenario, particularly with respect to the maintenance of these viruses in nature during interepidemic periods.

Severe coinfection of melioidosis and dengue fever in northeastern Brazil: first case report

This report focuses on a fatality involving severe dengue fever and melioidosis in a 28-year-old truck driver residing in Pacoti in northeastern Brazil. He exhibited long-term respiratory symptoms (48 days) and went through a wide-ranging clinical investigation at three hospitals, after initial clinical diagnoses of pneumonia, visceral leishmaniasis, tuberculosis, and fungal sepsis. After death, Burkholderia pseudomallei was isolated in a culture of ascitic fluid. Dengue virus type 1 was detected by polymerase chain reaction in cerebrospinal fluid (CSF); this infection was the cause of death. This description reinforces the need to consider melioidosis among the reported differential diagnoses of community-acquired infections where both melioidosis and dengue fever are endemic.

Concurrent infection with dengue virus type-2 and DENV-3 in a patient from Ceará, Brazil

Dengue outbreaks have occurred in several regions in Brazil and cocirculating dengue virus type 1 (DENV-1), DENV-2, and DENV-3 have been frequently observed. Dual infection by DENV-2 and DENV-3 was identified by type-specific indirect immunofluorescence assay and confirmed by reverse transcription polymerase chain reaction in a patient in Ceará with a mild disease. This is the first documented case of simultaneous infection with DENV-2 and DENV-3 in Brazil. Sequencing confirmed DENV-2 and DENV-3 (South-East/American) genotype III and (SriLanka/India), genotype III respectively.