José Wellington de Oliveira Lima

Epidemia de dengue em Fortaleza, Ceará: inquérito soro-epidemiológico aleatório

OBJETIVO: Seguindo-se a epidemia de dengue (DEN), em 1994, em Fortaleza, Ceara, causada pelo sorotipo 2 (DEN-2), realizou-se inquerito soro-epidemiologico aleatorio para avaliar e dimensionar o impacto da mesma e a prevalencia do dengue por distrito sanitario. METODO: Foi aplicado questionario contendo informacoes gerais, condicoes socio-economicas, informacoes sobre o quadro clinico e tempo de doenca. A amostra foi calculada para estimar uma prevalencia de 20%, com erro relativo de 10%, e intervalo de confianca de 95% (erro a de 5%). O sorteio e as analises foram realizadas por meio de computador usando programas apropriados. RESULTADOS E CONCLUSOES: Foram colhidas 1.341 amostras de soro de 9 distritos sanitarios, testadas por inibicao da hemaglutinacao, sendo classificadas como negativas e positivas (respostas primaria - RP e secundaria - RS). Foram reativas 588 (44%) amostras, sendo 93 (7%) RP e 495 (37%) RS. A prevalencia global em Fortaleza variou de 21% a 71%. Houve 41% (243/588) de infeccoes assintomaticas (IA) e 59% (346/588) sintomaticas (IS). Nao houve diferenca da prevalencia quanto ao sexo, faixa etaria e escolaridade, ao contrario da condicao socioeconomica que apresentou diferencas estatisticamente significantes (p < 0,001). Ocorreram mais IA (p<0,001) e IS (p<0,0001) em casos de RS que RP, com significância estatistica em ambos os sexos. Os sintomas mais prevalentes no casos confirmados foram febre, cefaleia, mialgias, exantema, mal estar geral, tontura e artralgias, sendo que prurido, dor ocular, exantema e gengivorragia foram estatisticamente significantes (p<0,005). Tontura e artralgias foram mais associados com RS que com RP, havendo diferencas estatisticas (p <0,05).OBJECTIVE A seroepidemiological random survey was carried out in Fortaleza city, State of Ceará, Brazil, following an epidemic of dengue virus type 2 (DEN 2), with the purpose of evaluating the frequency of clinical manifestations (signs and symptoms) and the prevalence of dengue infection. METHOD A questionnaire calling for information on address, sex, age, clinical, epidemiological and economic status was applied to the population, followed by venupuncture collection of 5-10 ml of blood for testing by hemagglutination-inhibition (HI). The sample was calculated to obtain a prevalence of 20% with relative risk of 10% and confidence interval of 95%. All information obtained was analyzed by computer using Epi Info 5.0, Lotus 123, Excel 5.0, and Stata software. RESULTS AND CONCLUSIONS A total of 1,341 serum samples were obtained from nine Health Districts (SD) and tested by hemagglutination inhibition. Of these, 589 (44%) were positive and 752 (56%) negative. Of the positive results, 93 primary responses (PR) (7%) to DEN-2 and 496 secondary responses (SR) (37%) were observed. The global prevalence in the SD ranged from 21% to 71%. There were 41% (243/589) asymptomatic infections and 59% (346/589) symptomatic infections. Data analysis showed no difference in frequency by sex, age, on schooling, although a highly statistically significant difference was found as between the different social classes, the infection most commonly observed being among people of better social status. The stratification of positive cases showed greater prevalence of AI (p < 0.001) and SI (p < 0.0001) in both sexes, among people with SR rather than PR. The most prevalent symptoms were fever, headache, muscle pains, rash, dizziness, and joint pains. Moreover, itching, retro-bulbar pain, rash, and gingival bleeding, showed statistically significant differences. On the other hand, dizziness and joint pains were more associated in the patients with SR than PR, and statistically significant differences were also observed.

Allergies and Diabetes as Risk Factors for Dengue Hemorrhagic Fever: Results of a Case Control Study

Background The physiopathology of dengue hemorrhagic fever (DHF), a severe form of Dengue Fever, is poorly understood. We are unable to identify patients likely to progress to DHF for closer monitoring and early intervention during epidemics, so most cases are sent home. This study explored whether patients with selected co-morbidities are at higher risk of developing DHF. Methods A matched case-control study was conducted in a dengue sero-positive population in two Brazilian cities. For each case of DHF, 7 sero-positive controls were selected. Cases and controls were interviewed and information collected on demographic and socio-economic status, reported co-morbidities (diabetes, hypertension, allergy) and use of medication. Conditional logistic regression was used to calculate the strength of the association between the co-morbidities and occurrence of DHF. Results 170 cases of DHF and 1,175 controls were included. Significant associations were found between DHF and white ethnicity (OR = 4.70; 2.17–10.20), high income (OR = 6.84; 4.09–11.43), high education (OR = 4.67; 2.35–9.27), reported diabetes (OR = 2.75; 1.12–6.73) and reported allergy treated with steroids (OR = 2.94; 1.01–8.54). Black individuals who reported being treated for hypertension had 13 times higher risk of DHF then black individuals reporting no hypertension. Conclusions This is the first study to find an association between DHF and diabetes, allergy and hypertension. Given the high case fatality rate of DHF (1–5%), we believe that the evidence produced in this study, when confirmed in other studies, suggests that screening criteria might be used to identify adult patients at a greater risk of developing DHF with a recommendation that they remain under observation and monitoring in hospital.

Resistência do Aedes aegypti ao temefós em Municípios do Estado do Ceará

The susceptibility of Aedes aegypti to temefos was evaluated by means of samples of eggs and larvae from four large counties in the state of Ceara (Fortaleza, Barbalha, Juazeiro do Norte and Crato). The technique standardized by the World Health Organization for tests with larvicides was used. The CL50 of eight samples from populations of Aedes was determined, as were their respective resistance ratios, compared to the CL50 of the susceptible Rockefeller strain. All populations submitted to the experiment showed resistance to temefos, with resistance ratios varying between 8 and 16. Analysis of these results reinforces prior evidence regarding the dissemination of temefos resistance in different locations in the state, subjected to considerable pressure for control in recent decades. The larvicide may lose its effectiveness if an urgent attempt is not made to reestablish the susceptibility of Aedes aegypti in these areas, profoundly affecting control campaigns currently under way.

Inquérito soro-epidemiológico na Ilha de São Luis durante epidemia de dengue no Maranhão

The Island of Sao Luis in the State of Maranhao, constituted by the municipalities of Sao Luis - SL (835,428 inhabitants), Sao Jose de Ribamar - SJR (60,633 inhabitants) and Paco do Lumiar - PL (80,274 inhabitants), has been suffering dengue (DEN) fever epidemics since 1995, caused by DEN-1. In 1996, from August through October, an aleatory sero-epidemiologic survey was carried out in order to estimate the incidence of DEN infection and to analyze other clinical and epidemiological parameters. A questionnaire was applied and serum samples were simultaneously obtained. Serum samples were tested by hemagglutination inhibition (HI). Results were analyzed using Lotus123, Epi-info 6.0, Excel 5.0 and STATA softwares. A total of 1,217 serum samples were obtained (101 of PL, 100 of SJR and 1017 of SL). The rate of DEN was 55.4% in PL, 28% in SJR and 41.4% in SL, suggesting the occurrence of 401,933 infections. No difference was seen between males and females, but infection occurred more in the upper social class than in poor people (p < 0.003), and was more frequent in adults than in children (p < 0.0004). In SL, the incidence was stratified into seven sanitary districts (SD), and prevalence was found to range from 26.1% in SD4 to 56.8% in SD1 (p < 0.0001). Symptoms were more frequently reported by people whose HI was positive: they included fever, headache, chills, dizziness, retrobulbar pains, muscle and joint pains, nausea, anorexia and skin rash. In spite of the high incidence of infection, no hemorrhagic cases were reported.The island of São Luis in the State of Maranhão, constituted by the municipalities of São Luis-SL (835,428 inhabitants), São José de Ribamar-SJR (60,633 inhabitants) and Paço do Lumiar-PL (80,274 inhabitants), has been suffering dengue (DEN) fever epidemics since 1995, caused by DEN-1. In 1996, from August through October, an aleatory sero-epidemiologic survey was carried out in order to estimate the incidence of DEN infection and to analyze other clinical and epidemiological parameters. A questionnaire was applied and serum samples were simultaneously obtained. Serum samples were tested by hemagglutination inhibition (HI). Results were analyzed using Lotus 123, Epi-info 6.0, Excel 5.0 and STATA softwares. A total of 1,217 serum samples were obtained (101 of PL, 100 of SJR and 1017 of SL). The rate of DEN was 55.4% in PL, 28% in SJR and 41.4% in SL, suggesting the occurrence of 401,933 infections. No difference was seen between males and females, but infection occurred more in the upper social class than in poor people (p < 0.003), and was more frequent in adults than in children (p < 0.0004). In SL, the incidence was stratified into seven sanitary districts (SD), and prevalence was found to range from 26.1% in SD4 to 56.8% in SD1 (p < 0.0001). Symptoms were more frequently reported by people whose HI was positive: they included fever, headache, chills, dizziness, retrobulbar pains, muscle and joint pains, nausea, anorexia and skin rash. In spite of the high incidence of infection, no hemorrhagic cases were reported.

Prevalence and associated factors to hepatitis C in hemodialysis patients in Brazil

OBJECTIVE The prevalence of hepatitis C virus (HCV) is higher in patients on hemodialysis than in the general population, probably due to greater exposure to risk situations. The purposes of the study were to determine anti-HCV antibodies prevalence among hemodialysis patients and dialysis clinics and patients factors associated with HCV transmission. METHODS A cross-sectional study was conducted in 752 hemodialysis patients in all 12 dialysis clinics of Fortaleza, Brazil, and were screened using third generation ELISA. Sociodemographic, clinical, and epidemiological data of 663 patients were collected through interviews. Nosocomial factors were assessed using a specific questionnaire tool. Statistical analysis was conducted using Students t test, odds ratio and multivariate analysis. RESULTS The prevalence of anti-HCV was 52% (390/746; ranged from 6% to 72%). The anti-HCV positivity was higher in patients who had previous peritoneal dialysis (OR=1.76; 95% CI 1.12-2.76) and blood transfusion (OR=2.75; 95% CI 1.25-6.03). Dialysis age has been associated with anti-HCV positivity (OR=1.47; 95% CI 1.35-1.61). Clinics practices associated with anti-HCV positivity were: previous preparing of heparin (OR=2.92; 95% CI 1.23-6.92), failure in gloves use or change (OR=5.73; 95% CI 1.75-18.72), unsatisfactory dialysis machine disinfection (OR=2.79; 95% CI 1.57-4.96), and patient isolation in dialysis room (OR=0.18; 95% CI 0.05-0.61). CONCLUSIONS The results show high anti-HCV prevalence among hemodialysis patients and the association of nosocomial factors with new HCV infection cases.

Avaliação do impacto na infestação por Aedes aegypti em tanques de cimento do município de Canindé, Ceará, Brasil, após a utilização do peixe Betta splendens como alternativa de controle biológico

Caninde has a population of 71,235 inhabitants. In April 2001, the city started using larvivorous fish in cement water tanks, as a means of biological control of Aedes aegypti larvae. During house-to-house visits by health agents, instead of treating the water tank with larvicide, a Betta splendens fish was introduced into each tank. The number of houses and the number of tanks was estimated by monthly surveys. Then, the number of tanks per house was determined. Taking into account this estimated number and the number of houses visited, the infestation level for each kind of deposit was analyzed. In January 2001, 70.4% of the water tanks presented mosquitoes. Following the intervention, in January 2002 only 7.4% were positive and by December 2002 the rate had dropped to 0.2%. The efficacy of Betta splendens as a biological control agent in cement water tanks was clearly demonstrated, by achieving a 320 times reduction in the infestation level.

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.

Competência de peixes como predadores de larvas de Aedes aegypti, em condições de laboratório

OBJETIVO: Avaliar a competencia de peixes na predacao de larvas de Aedes aegypti, em condicoes de laboratorio. METODOS: Foram testados machos e femeas de cinco especies de peixe. Os testes de predacao duravam cinco semanas para cada especie. Cada ensaio compreendia quatro caixas testes e quatro caixas controles. Das caixas controle, duas tinham somente um peixe e as outras duas, apenas larvas. Cada caixa teste continha um peixe e larvas. Na primeira semana foram expostas 100 larvas em cada caixa, e a cada semana acrescentavam-se 100 larvas por caixa/dia, ate se obter um maximo de 500 larvas/dia. Comprimento e peso dos peixes foram medidos semanalmente. RESULTADOS: Foram utilizadas 369.000 larvas no total. O Trichogaster trichopteros foi a unica especie em que ambos os sexos predaram 100% das larvas oferecidas. O Betta splendens deixou de predar apenas 15 larvas. Machos do Poecilia reticulata apresentaram baixa capacidade larvofaga quando comparados as femeas da mesma especie. Em relacao ao peso e tamanho o Betta splendens mostrou-se capaz de predar 523 larvas/grama/dia. CONCLUSOES: Femeas e machos de Trichogaster trichopteros e de Astyanax fasciatus, e femeas de Betta splendens e de Poecillia sphenops foram os peixes que apresentaram maior competencia para predar as larvas. Embora com competencia menor, machos de Poecillia sphenops e femeas de Poecilia reticulata foram capazes de eliminar o numero de larvas de Aedes aegypti que possam emergir durante 24 horas num criadouro, em condicoes naturais. Machos de Poecilia reticulata nao foram predadores eficazes.

Efeito residual de apresentações comerciais dos larvicidas temefos e Bacillus thuringiensis israelensis sobre larvas de Aedes aegypti em recipientes com renovação de água

The residual effect of temefos (commercial applications A, B and C) and Bacillus thuringiensis israelensis (D and E) on Aedes aegypti larvae was evaluated, in recipients with water renewal. Forty-four beakers of 1,000ml each (8 for each application and 4 controls) were used. In each beaker, 25 larvae were introduced daily. After 24 hours, the dead larvae were counted, the beakers emptied to 200ml and refilled to original volume, with addition of new larvae. The duration of the maximum residual effect (100% of mortality) was: A-19; B-39; C-40; D-8; E-19 days. The mortality ratio of all applications remained equivalent for 25 days; B, C and E maintained MR equivalent up to 45 days; B and C showed MR 2.40 times greater than E, between 46-95 days; B, compared with A, showed MR 1.90-7.51 times greater between 26-95 days. The conclusion was greater effectiveness of two presentations of temefos, even in an epidemiological situation with long exposure to the product and renewal of water in recipients.

Comparative study of cystatin C and serum creatinine in the estimative of glomerular filtration rate in children

BACKGROUND To compare estimated glomerular filtration rate (GFR) by Schwartz formula and cystatin C-derived formula in a large population of children with a large spectrum of renal disease. METHODS Serum creatinine, cystatin C and estimated GFR were determined in 273 children, 254 with renal disease, and a mean age of 10.0+/-4.4 y. Nineteen children were used as control, with a mean age of 8.5+/-4.2 y. RESULTS The children had nephrotic syndrome (16.5%), glomerulonephritis (11.4%), neurogenic bladder (11.4%), hydronephrosis (9.8%), asymptomatic hematuria (11%), chronic renal disease (5.9%) and other diseases (11%). Cystatin C, creatinine, Schwartz estimated GFR and cystatin C estimated GFR (mean+/-SD) were 1.30+/-1.03 mg/dl, 0.82+/-1.20 mg/l, 143+/-72 ml/min/1.73 m(2) and 88+/-36 ml/min/1.73 m(2), respectively. Although GFR estimated by creatinine and cystatin C had a significant correlation, the Bland-Altman analysis showed greater differences between GFR estimated by the 2 methods, with a mean difference of 50 ml/min. Besides, >50% of the patients with a reduced cystatin C estimated GFR had a normal GFR when analyzed by the Schwartz formula. CONCLUSIONS Our data shows that cystatin C-based GFR is more sensitive than previous study had demonstrated. It is important to perform studies in specific populations to determine the variability in GFR measurements.