Carlos Henrique Alencar

Zika virus outbreak in Brazil

Zika virus (ZIKV) infection is spreading rapidly within the Americas after originating from an outbreak in Brazil. We describe the current ZIKV infection epidemic in Brazil and the neurological symptoms arising. First cases of an acute exanthematic disease were reported in Brazils Northeast region at the end of 2014. In March 2015, autochthonous ZIKV was determined to be the causative agent of the exanthematic disease. As cases of neurological syndromes in regions where ZIKV, dengue and/or Chikungunya viruses co-circulate were reported, ZIKV was also identified in the cerebrospinal fluid of patients with acute neurological syndromes and previous exanthematic disease. By the end of September 2015, an increasing number of infants with small head circumference or microcephaly were noted in Brazils Northeast which was estimated to be 29 cases between August and October. ZIKV was identified in blood and tissue samples of a newborn and in mothers who had given birth to infants with microcephaly and ophthalmological anomalies. In 2015, there were an estimated 440,000 - 1,300,000 Zika cases in Brazil. There have been 4,783 suspected cases of microcephaly, most of them in the Northeast of Brazil associated with 76 deaths. The Ministry of Health is intensifying control measures against the mosquito Aedes aegypti and implemented intensive surveillance actions. Further studies are needed to confirm the suspected association between ZIKV infection and microcephaly; to identify antiviral, immunotherapy, or prophylactic vaccine; to introduce diagnostic ELISA testing. Clinical and epidemiological studies must be performed to describe viral dynamics and expansion of the outbreak.

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.

Prevalence of Chagas disease in Brazil: a systematic review and meta-analysis.

Chagas disease is a major public health problem in Brazil and Latin America. During the last years, it has become an emerging problem in North America and Europe due to increasing international migration. Here we describe the prevalence of Chagas disease in Brazil through a systematic review. We searched national and international electronic databases, grey literature and reference lists of selected articles for population-based studies on Chagas disease prevalence in Brazil, performed from 1980 until September 2012. Forty-two articles with relevant prevalence data were identified from a total of 4985 references. Prevalence ranged from 0% to 25.1%. Most surveys were performed in the Northeast region, especially in the state of Piauí. We observed a high degree of heterogeneity in most pooled estimates (I(2)>75%; p<0.001). The pooled estimate of Chagas disease prevalence across studies for the entire period was 4.2% (95% CI: 3.1-5.7), ranging from 4.4% (95% CI: 2.3-8.3) in the 1980s to 2.4% (95% CI: 1.5-3.8) after 2000. Females (4.2%; 95% CI: 2.6-6.8), >60 year-olds (17.7%; 95% CI: 11.4-26.5), Northeast (5.0%; 95% CI: 3.1-8.1) and Southeast (5.0%; CI: 2.4-9.9) regions and mixed (urban/rural) areas (6.4%; 95% CI: 4.2-9.4) had the highest pooled prevalence. About 4.6 million (95% CI: 2.9-7.2 million) of people are estimated to be infected with Trypanosoma cruzi. The small number of studies and small-scale samples of the general population in some areas limit interpretation, and findings of this review do not necessarily reflect the situation of the entire country. Systematic population-based studies at regional and national level are recommended to provide more accurate estimates and better define the epidemiology and risk areas of Chagas disease in Brazil.

Mortality and case fatality due to visceral leishmaniasis in Brazil: a nationwide analysis of epidemiology, trends and spatial patterns.

Background Visceral leishmaniasis (VL) is a significant public health problem in Brazil and several regions of the world. This study investigated the magnitude, temporal trends and spatial distribution of mortality related to VL in Brazil. Methods We performed a study based on secondary data obtained from the Brazilian Mortality Information System. We included all deaths in Brazil from 2000 to 2011, in which VL was recorded as cause of death. We present epidemiological characteristics, trend analysis of mortality and case fatality rates by joinpoint regression models, and spatial analysis using municipalities as geographical units of analysis. Results In the study period, 12,491,280 deaths were recorded in Brazil. VL was mentioned in 3,322 (0.03%) deaths. Average annual age-adjusted mortality rate was 0.15 deaths per 100,000 inhabitants and case fatality rate 8.1%. Highest mortality rates were observed in males (0.19 deaths/100,000 inhabitants), <1 year-olds (1.03 deaths/100,000 inhabitants) and residents in Northeast region (0.30 deaths/100,000 inhabitants). Highest case fatality rates were observed in males (8.8%), ≥70 year-olds (43.8%) and residents in South region (17.7%). Mortality and case fatality rates showed a significant increase in Brazil over the period, with different patterns between regions: increasing mortality rates in the North (Annual Percent Change – APC: 9.4%; 95% confidence interval – CI: 5.3 to 13.6), and Southeast (APC: 8.1%; 95% CI: 2.6 to 13.9); and increasing case fatality rates in the Northeast (APC: 4.0%; 95% CI: 0.8 to 7.4). Spatial analysis identified a major cluster of high mortality encompassing a wide geographic range in North and Northeast Brazil. Conclusions Despite ongoing control strategies, mortality related to VL in Brazil is increasing. Mortality and case fatality vary considerably between regions, and surveillance and control measures should be prioritized in high-risk clusters. Early diagnosis and treatment are fundamental strategies for reducing case fatality of VL in Brazil.

Clusters of leprosy transmission and of late diagnosis in a highly endemic area in Brazil: focus on different spatial analysis approaches

Objective  The Brazilian National Hansen’s Disease Control Program recently identified clusters with high disease transmission. Herein, we present different spatial analytical approaches to define highly vulnerable areas in one of these clusters.

Hanseníase no município de Fortaleza, CE, Brasil: aspectos epidemiológicos e operacionais em menores de 15 anos (1995-2006)

This is a sectional study that aims to analyze the occurrence of Hansens disease cases in 15 year-old minors in the Municipality of Fortaleza and notified in SINAN. The epidemiological indicators in this population show hiperendemicity. In operational terms is observed the maintenance of the service concentration in some reference units, in spite of some progress. Late diagnosis, a high degree of incapacity in the diagnosis and low degree of evaluation of contacts registered reveal the fragility of the actions of control. This study emphasizes the possibility of error diagnostic front to the characteristics of the infection in this population. The occurrence of cases of leprosy in this population represents an epidemiologic indicator of great importance and its analysis extends the discussion on operational problems in the network of health services.Estudio transversal con el objetivo de analizar las ocurrencias de los casos de lepra en menores de 15 anos de edad sitiados en la ciudad de Fortaleza y enterados en el SINAN. Los indicadores epidemicos en esta poblacion se presentaron hiperendemicos. En la operacinalizacion, se observa el mantenimiento de la concentracion de atencion en algunas unidades recomendables, a pesar de algunos avances. Diagnosticos muy tardes, gran grado de incapacidad en el diagnostico y bajo grado de evaluacion de contactos registrados, muestran la fragilidad de las acciones de control. Se resalta asi la posibilidad de error de diagnostico delante de las caracteristicas de la infeccion en esta poblacion. La ocurrencia de casos de lepra en esta poblacion representa un indicador epidemico de gran importancia y su analisis amplia la discusion sobre los problemas operacionales en la red de servicios publicos.

Mortality of Chagas’ disease in Brazil: spatial patterns and definition of high‐risk areas

Objective  To describe patterns of spatial distribution of mortality associated with Chagas’ disease in Brazil.

Interruption and defaulting of multidrug therapy against leprosy: population-based study in Brazil's Savannah Region.

Background Low adherence to multidrug therapy against leprosy (MDT) is still an important obstacle of disease control, and may lead to remaining sources of infection, incomplete cure, irreversible complications, and multidrug resistance. Methodology/Principal Finding We performed a population-based study in 78 municipalities in Tocantins State, central Brazil, and applied structured questionnaires on leprosy-affected individuals. We used two outcomes for assessment of risk factors: defaulting (not presenting to health care center for supervised treatment for >12 months); and interruption of MDT. In total, 28/936 (3.0%) patients defaulted, and 147/806 (18.2%) interrupted MDT. Defaulting was significantly associated with: low number of rooms per household (OR = 3.43; 0.98–9.69; p = 0.03); moving to another residence after diagnosis (OR = 2.90; 0.95–5.28; p = 0.04); and low family income (OR = 2.42; 1.02–5.63: p = 0.04). Interruption of treatment was associated with: low number of rooms per household (OR = 1.95; 0.98–3.70; p = 0.04); difficulty in swallowing MDT drugs (OR = 1.66; 1.03–2.63; p = 0.02); temporal non-availability of MDT at the health center (OR = 1.67; 1.11–2.46; p = 0.01); and moving to another residence (OR = 1.58; 95% confidence interval: 1.03–2.40; p = 0.03). Logistic regression identified temporal non-availability of MDT as an independent risk factor for treatment interruption (adjusted OR = 1.56; 1.05–2.33; p = 0.03), and residence size as a protective factor (adjusted OR = 0.89 per additional number of rooms; 0.80–0.99; p = 0.03). Residence size was also independently associated with defaulting (adjusted OR = 0.67; 0.52–0.88; p = 0.003). Conclusions Defaulting and interruption of MDT are associated with some poverty-related variables such as family income, household size, and migration. Intermittent problems of drug supply need to be resolved, mainly on the municipality level. MDT producers should consider oral drug formulations that may be more easily accepted by patients. Thus, an integrated approach is needed for further improving control, focusing on vulnerable population groups and the local health system.

Reduced oviposition of Aedes aegypti gravid females in domestic containers with predatory fish

The presence of pathogens or predators in water may alter oviposition behaviour of gravid female Aedes aegypti mosquitoes. We evaluated the oviposition behaviour of A. aegypti in recipients containing larvivorous fish (Betta splendens and Poecilia reticulata). In four breeders, fish specimens were placed in 15 l of dechlorined water. Four control breeders only contained dechlorined water. Breeders with eucatex ovitraps and approximately 100 male and female mosquitoes were placed in wire netting cages. During a period of 7 weeks, eggs on the ovitraps were counted weekly. The median number of eggs laid in recipients with B. splendens (32.5/week) was lower than in those with P. reticulata (200.5/week) and the control group (186.5/week; P < 0.0001). The oviposition activity index (OAI) for P. reticulata did not show any considerable difference between posture in deposits with and without fish (‐0005). Deposits with B. splendens showed a lower position than those used as controls (‐0627). We conclude that B. splendens can be used to effectively prevent gravid A. aegypti females from laying eggs in large water containers.

Trends in schistosomiasis-related mortality in Brazil, 2000-2011.

Schistosomiasis is an important public health problem, with high morbidity and mortality in endemic countries. We analysed the epidemiological characteristics and time trends of schistosomiasis-related mortality in Brazil. We performed a nationwide study based on official mortality data obtained from the Brazilian Mortality Information System. We included all deaths in Brazil between 2000 and 2011, in which schistosomiasis was mentioned on the death certificate as an underlying or associated cause of death (multiple causes of death). We calculated crude and age-adjusted mortality rates (per 100,000 inhabitants), and proportional mortality rates. Trends over time were assessed using joinpoint regression models. Over the 12-year study period, 12,491,280 deaths were recorded in Brazil. Schistosomiasis was mentioned in 8,756 deaths, including in 6,319 (72.2%) as an underlying cause and in 2,437 (27.8%) as an associated cause. The average annual age-adjusted mortality rate was 0.49 deaths/100,000 inhabitants (95% confidence interval: 0.46-0.52) and proportional mortality rate was 0.070% (95% confidence interval: 0.069-0.072). Males (0.53 deaths/100,000 inhabitants), those aged ⩾70years (3.41 deaths/100,000 inhabitants), those of brown race/colour (0.44 deaths/100,000 inhabitants), and residents in the Northeast region of Brazil (1.19 deaths/100,000 inhabitants) had the highest schistosomiasis-related death rates. Age-adjusted mortality rates showed a significant decrease at a national level (Annual Percent Change: -2.8%; 95% confidence interval: -4.2 to -2.4) during the studied period. We observed decreasing mortality rates in the Northeast (Annual Percent Change: -2.5%; 95% confidence interval: -4.2 to -0.8), Southeast (Annual Percent Change: -2.2%; 95% confidence interval: -3.6 to -0.9), and Central-West (Annual Percent Change: -7.9%; 95% confidence interval: -11.3 to -4.3) regions, while the rates remained stable in the North and South regions. Despite the reduced mortality, schistosomiasis is still a neglected cause of death in Brazil, with considerable regional differences. Sustainable control measures should focus on increased coverage, and intensified and tailored control measures, to prevent the occurrence of severe forms of schistosomiasis and associated deaths.