Patrícia Brasil

Malaria in Brazil: an overview

Malaria is still a major public health problem in Brazil, with approximately 306 000 registered cases in 2009, but it is estimated that in the early 1940s, around six million cases of malaria occurred each year. As a result of the fight against the disease, the number of malaria cases decreased over the years and the smallest numbers of cases to-date were recorded in the 1960s. From the mid-1960s onwards, Brazil underwent a rapid and disorganized settlement process in the Amazon and this migratory movement led to a progressive increase in the number of reported cases. Although the main mosquito vector (Anopheles darlingi) is present in about 80% of the country, currently the incidence of malaria in Brazil is almost exclusively (99,8% of the cases) restricted to the region of the Amazon Basin, where a number of combined factors favors disease transmission and impair the use of standard control procedures. Plasmodium vivax accounts for 83,7% of registered cases, while Plasmodium falciparum is responsible for 16,3% and Plasmodium malariae is seldom observed. Although vivax malaria is thought to cause little mortality, compared to falciparum malaria, it accounts for much of the morbidity and for huge burdens on the prosperity of endemic communities. However, in the last few years a pattern of unusual clinical complications with fatal cases associated with P. vivax have been reported in Brazil and this is a matter of concern for Brazilian malariologists. In addition, the emergence of P. vivax strains resistant to chloroquine in some reports needs to be further investigated. In contrast, asymptomatic infection by P. falciparum and P. vivax has been detected in epidemiological studies in the states of Rondonia and Amazonas, indicating probably a pattern of clinical immunity in both autochthonous and migrant populations. Seropidemiological studies investigating the type of immune responses elicited in naturally-exposed populations to several malaria vaccine candidates in Brazilian populations have also been providing important information on whether immune responses specific to these antigens are generated in natural infections and their immunogenic potential as vaccine candidates. The present difficulties in reducing economic and social risk factors that determine the incidence of malaria in the Amazon Region render impracticable its elimination in the region. As a result, a malaria-integrated control effort - as a joint action on the part of the government and the population - directed towards the elimination or reduction of the risks of death or illness, is the direction adopted by the Brazilian government in the fight against the disease.

Zika Virus Outbreak in Rio de Janeiro, Brazil: Clinical Characterization, Epidemiological and Virological Aspects

Background In 2015, Brazil was faced with the cocirculation of three arboviruses of major public health importance. The emergence of Zika virus (ZIKV) presents new challenges to both clinicians and public health authorities. Overlapping clinical features between diseases caused by ZIKV, Dengue (DENV) and Chikungunya (CHIKV) and the lack of validated serological assays for ZIKV make accurate diagnosis difficult. Methodology / Principal Findings The outpatient service for acute febrile illnesses in Fiocruz initiated a syndromic clinical observational study in 2007 to capture unusual presentations of DENV infections. In January 2015, an increase of cases with exanthematic disease was observed. Trained physicians evaluated the patients using a detailed case report form that included clinical assessment and laboratory investigations. The laboratory diagnostic algorithm included assays for detection of ZIKV, CHIKV and DENV. 364 suspected cases of Zika virus disease were identified based on clinical criteria between January and July 2015. Of these, 262 (71.9%) were tested and 119 (45.4%) were confirmed by the detection of ZIKV RNA. All of the samples with sequence information available clustered within the Asian genotype. Conclusions / Significance This is the first report of a ZIKV outbreak in the state of Rio de Janeiro, based on a large number of suspected (n = 364) and laboratory confirmed cases (n = 119). We were able to demonstrate that ZIKV was circulating in Rio de Janeiro as early as January 2015. The peak of the outbreak was documented in May/June 2015. More than half of the patients reported headache, arthralgia, myalgia, non-purulent conjunctivitis, and lower back pain, consistent with the case definition of suspected ZIKV disease issued by the Pan American Health Organization (PAHO). However, fever, when present, was low-intensity and short-termed. In our opinion, pruritus, the second most common clinical sign presented by the confirmed cases, should be added to the PAHO case definition, while fever could be given less emphasis. The emergence of ZIKV as a new pathogen for Brazil in 2015 underscores the need for clinical vigilance and strong epidemiological and laboratory surveillance.

Guillain-Barré syndrome associated with Zika virus infection

A 24-year-old housekeeper presented to hospital in Rio de Janeiro in June, 2014, with headache, fever, and a rash, 5 days after waking with a severe generalised headache, retro-orbital pain, weakness, and paraesthesia of the hands and feet. 2 days later she developed fever (axillary temperature 42°C), chills, and a pruritic rash on the face, abdomen, chest, and arms. By day 4, she was afebrile but had painful swelling of the hands (appendix) and feet, diffi culty walking, and disseminated rash. She had had dengue 5 years previously, had not travelled recently, and did not recall any tick or mosquito bites. On examination, she was alert and fully oriented. Axillary temperature was 36·7°C, pulse 90 beats per min, blood pressure 100/60 mm Hg, and respiratory rate 20 breaths per min. She had a diff use erythematous macular rash, bilateral non-purulent conjunctival hyperaemia, enanthema of the palate, one enlarged painless cervical lymph node, and swelling of the hands and feet, but no signs of meningism. She had reduced strength in the legs, absent deep tendon refl exes at the knees and ankles, and both plantars were absent; sensation to light touch was reduced in the legs, but she had no urinary retention or ataxia. Examination, including neurological examination of the arms, was otherwise normal. Lumbar puncture (day 6), nerve conduction studies and an electromyogram (day 10), and a non-enhanced MRI (day 13) were normal. From day 10 the rash and swelling began to resolve with supportive treatment. By day 13 she was fully mobile and could be discharged. At follow-up on day 41, her only remaining symptom was persistent headache. We investigated her serum and cerebrospinal fl uid (CSF) for dengue, chikungunya, and Zika viruses. Realtime PCR for dengue and chikungunya was negative, but PCR was positive for Zika virus in serum (day 5), CSF (day 6), saliva (day 10), and urine (day 11). The CSF and acute and convalescent serum were negative for dengue and chikungunya by IgM-capture ELISA. Zika ELISA was not available. To identify the Zika virus genotype we sequenced 327 base pair amplicons encompassing the envelope protein, and identifi ed the Asian lineage of Zika in the CSF (fi gure). Like dengue and chikungunya, Zika virus causes a febrile illness with rash. During the 2013 outbreak of Zika virus in French Polynesia an apparent increase in Guillain-Barre syndrome incidence was noted but with no baseline data for comparison. One case had antibodies against Zika and dengue viruses (which can also trigger Guillain-Barre syndrome), but no virus was detected. Our patient had no evidence of dengue or chikungunya infection, but Zika was found in the CSF by PCR, and unusually she also had high grade fever and clinical features consistent with paraparetic Guillain-Barre syndrome, a rare atypical presentation. CSF and neurophysiological investigations were normal, as is often found early in Guillain-Barre syndrome. She met Level III of diagnostic certainty for Guillain-Barre syndrome in the Brighton classifi cation (consistent clinical features, but no supporting CSF or neurophysiology evidence). Our case highlights the potential for neurotropism of Zika virus, and the need to consider this emerging virus as a mosquito-borne cause of fever, rash, and neurological disease.

From Mosquitos to Humans: Genetic Evolution of Zika Virus

Initially isolated in 1947, Zika virus (ZIKV) has recently emerged as a significant public health concern. Sequence analysis of all 41 known ZIKV RNA open reading frames to date indicates that ZIKV has undergone significant changes in both protein and nucleotide sequences during the past half century.

Isolation of Infective Zika Virus from Urine and Saliva of Patients in Brazil

Background Zika virus (ZIKV) is an emergent threat provoking a worldwide explosive outbreak. Since January 2015, 41 countries reported autochthonous cases. In Brazil, an increase in Guillain-Barré syndrome and microcephaly cases was linked to ZIKV infections. A recent report describing low experimental transmission efficiency of its main putative vector, Ae. aegypti, in conjunction with apparent sexual transmission notifications, prompted the investigation of other potential sources of viral dissemination. Urine and saliva have been previously established as useful tools in ZIKV diagnosis. Here, we described the presence and isolation of infectious ZIKV particles from saliva and urine of acute phase patients in the Rio de Janeiro state, Brazil. Methodology/Principal Findings Nine urine and five saliva samples from nine patients from Rio de Janeiro presenting rash and other typical Zika acute phase symptoms were inoculated in Vero cell culture and submitted to specific ZIKV RNA detection and quantification through, respectively, NAT-Zika, RT-PCR and RT-qPCR. Two ZIKV isolates were achieved, one from urine and one from saliva specimens. ZIKV nucleic acid was identified by all methods in four patients. Whenever both urine and saliva samples were available from the same patient, urine viral loads were higher, corroborating the general sense that it is a better source for ZIKV molecular diagnostic. In spite of this, from the two isolated strains, each from one patient, only one derived from urine, suggesting that other factors, like the acidic nature of this fluid, might interfere with virion infectivity. The complete genome of both ZIKV isolates was obtained. Phylogenetic analysis revealed similarity with strains previously isolated during the South America outbreak. Conclusions/Significance The detection of infectious ZIKV particles in urine and saliva of patients during the acute phase may represent a critical factor in the spread of virus. The epidemiological relevance of this finding, regarding the contribution of alternative non-vectorial ZIKV transmission routes, needs further investigation.

First detection of natural infection of Aedes aegypti with Zika virus in Brazil and throughout South America

Zika virus (ZIKV) has caused a major epidemic in Brazil and several other American countries. ZIKV is an arbovirus whose natural vectors during epidemics have been poorly determined. In this study, 1,683 mosquitoes collected in the vicinity of ZIKV suspected cases in Rio de Janeiro, Brazil, from June 2015 to May 2016 were screened for natural infection by using molecular methods. Three pools of Aedes aegypti were found with the ZIKV genome, one of which had only one male. This finding supports the occurrence of vertical and/or venereal transmission of ZIKV in Ae. aegypti in nature. None of the examined Ae. albopictus and Culex quinquefasciatus was positive. This is the first report of natural infection by ZIKV in mosquitoes in Brazil and other South American countries. So far, Ae. aegypti is the only confirmed vector of ZIKV during the ongoing Pan-American epidemics.

Malaria in Brazil: what happens outside the Amazonian endemic region

Brazil, a country of continental proportions, presents three profiles of malaria transmission. The first and most important numerically, occurs inside the Amazon. The Amazon accounts for approximately 60% of the nation’s territory and approximately 13% of the Brazilian population. This region hosts 99.5% of the nation’s malaria cases, which are predominantly caused by Plasmodium vivax (i.e., 82% of cases in 2013). The second involves imported malaria, which corresponds to malaria cases acquired outside the region where the individuals live or the diagnosis was made. These cases are imported from endemic regions of Brazil (i.e., the Amazon) or from other countries in South and Central America, Africa and Asia. Imported malaria comprised 89% of the cases found outside the area of active transmission in Brazil in 2013. These cases highlight an important question with respect to both therapeutic and epidemiological issues because patients, especially those with falciparum malaria, arriving in a region where the health professionals may not have experience with the clinical manifestations of malaria and its diagnosis could suffer dramatic consequences associated with a potential delay in treatment. Additionally, because the Anopheles vectors exist in most of the country, even a single case of malaria, if not diagnosed and treated immediately, may result in introduced cases, causing outbreaks and even introducing or reintroducing the disease to a non-endemic, receptive region. Cases introduced outside the Amazon usually occur in areas in which malaria was formerly endemic and are transmitted by competent vectors belonging to the subgenus Nyssorhynchus (i.e., Anopheles darlingi, Anopheles aquasalis and species of the Albitarsis complex). The third type of transmission accounts for only 0.05% of all cases and is caused by autochthonous malaria in the Atlantic Forest, located primarily along the southeastern Atlantic Coast. They are caused by parasites that seem to be (or to be very close to) P. vivax and, in a less extent, by Plasmodium malariae and it is transmitted by the bromeliad mosquito Anopheles (Kerteszia) cruzii. This paper deals mainly with the two profiles of malaria found outside the Amazon: the imported and ensuing introduced cases and the autochthonous cases. We also provide an update regarding the situation in Brazil and the Brazilian endemic Amazon.

Fatal encephalitis associated with Zika virus infection in an adult

BACKGROUND Zika virus (ZIKV) was first identified in the Americas in 2015, when an outbreak of an exanthematous illness occurred in Brazil. Subsequentely, there was an increase of microcephaly cases, suggesting an association between ZIKV and this neurological complication. Currently, ZIKV has been recognised as causing a wide range of neurological complications including Guillain Barré syndrome, and myelitis. OBJECTIVES In this report, we describe the first fatal case of encephalitis in a 47 years old non pregnant woman, infected during the Brazilian zika epidemic of 2016. STUDY DESIGN The diagnosis of encephalitis was determined by the presence of a disturbed level of consciousness and focal neurological signs during an exanthemous viral infection. RESULTS CSF analysis supported the diagnosis of viral encephalitis, revealing lymphocytic pleocytosis, a high protein concentration, and the presence of IgM zika antibodies. RT-PCR analysis for ZIKV was positive in the urine. A brain computed tomography showed massive brain swelling. Our case differs from previous reports, because her neurological picture developed rapidly and in a very aggressive manner leading to brain death after eleven days of admission. CONCLUSION In endemic areas, ZIKV should be considered as an aetiological agent in cases of encephalitis, and clinicians should be aware of its potential severity.

Culex quinquefasciatus from Rio de Janeiro Is Not Competent to Transmit the Local Zika Virus

Background The Americas have suffered a dramatic epidemic of Zika since May in 2015, when Zika virus (ZIKV) was first detected in Brazil. Mosquitoes belonging to subgenus Stegomyia of Aedes, particularly Aedes aegypti, are considered the primary vectors of ZIKV. However, the rapid spread of the virus across the continent raised several concerns about the transmission dynamics, especially about potential mosquito vectors. The purpose of this work was to assess the vector competence of the house mosquito Culex quinquefasciatus from an epidemic Zika area, Rio de Janeiro, Brazil, for local circulating ZIKV isolates. Methodology/Principal Findings Culex quinquefasciatus and Ae. aegypti (positive control of ZIKV infection) from Rio de Janeiro were orally exposed to two ZIKV strains isolated from human cases from Rio de Janeiro (Rio-U1 and Rio-S1). Fully engorged mosquitoes were held in incubators at 26 ± 1°C, 12 h:12 h light:dark cycle and 70 ± 10% humidity. For each combination mosquito population—ZIKV strain, 30 specimens were examined for infection, dissemination and transmission rates, at 7, 14 and 21 days after virus exposure by analyzing body (thorax plus abdomen), head and saliva respectively. Infection rates were minimal to completely absent in all Cx. quinquefasciatus-virus combinations and were significantly high for Ae. aegypti. Moreover, dissemination and transmission were not detected in any Cx. quinquefasciatus mosquitoes whatever the incubation period and the ZIKV isolate. In contrast, Ae. aegypti ensured high viral dissemination and moderate to very high transmission. Conclusions/Significance The southern house mosquito Cx. quinquefasciatus from Rio de Janeiro was not competent to transmit local strains of ZIKV. Thus, there is no experimental evidence that Cx. quinquefasciatus likely plays a role in the ZIKV transmission. Consequently, at least in Rio, mosquito control to reduce ZIKV transmission should remain focused on Ae. aegypti.

First detection of autochthonous Zika virus transmission in a HIV-infected patient in Rio de Janeiro, Brazil

Since May 2015, Brazils Ministry of Health has reported autochthonous transmission of Zika virus (ZIKV) in some states of the country. Simultaneous circulation of Dengue, Chikungunya and ZIKV in the country hinder both the diagnosis and the therapeutic approach of patients seeking care with acute febrile illnesses especially in patients with comorbidities. The association between HIV infection and endemic diseases has been described especially in tropical regions with varying levels of complications, although there has been no report of ZIKV in HIV-infected patients. We report the first autochthonous case of laboratory confirmed ZIKV infection in a HIV-infected patient in Rio de Janeiro, Brazil. He evolved with only mild symptoms and recovered well without major laboratory abnormalities. Phylogenetic analysis of the ZIKV detected in the patient sera clustered within the Asian clade. To the best of our knowledge, this is the first time that Zika virus co-infection is reported in a HIV-infected patient.