Case-control study on infant mortality in Southern Brazil

OBJECTIVE: To identify risk factors associated with infant mortality and, more specifically, with neonatal mortality. METHODS: A case-control study was carried out in the municipality of Caxias do Sul, Southern Brazil. Characteristics of prenatal care and causes of mortality were assessed for all live births in the 2001-2002 period with a completed live-birth certificate and whose mothers lived in the municipality. Cases were defined as all deaths within the first year of life. As controls, there were selected the two children born immediately after each case in the same hospital, who were of the same sex, and did not die within their first year of life. Multivariate analysis was performed using conditional logistic regression. RESULTS: There was a reduction in infant mortality, the greatest reduction was observed in the post-neonatal period. The variables gestational age (<36 weeks), birth weight (<2,500 g), and 5-minute Apgar (<6) remained in the final model of the multivariate analysis, after adjustment. CONCLUSIONS: Perinatal conditions comprise almost the totality of neonatal deaths, and the majority of deaths occur at delivery. The challenge for reducing infant mortality rate in the city is to reduce the mortality by perinatal conditions in the neonatal period.

Retreatment in leprosy: a case-control study

OBJECTIVE: To assess risk factors for retreatment of leprosy patients. METHODS: A case-control study with patients from two reference care units in Recife, northeastern Brazil, in 2003. The case group included retreated patients (N=155) and the control group comprised those patients who were not retreated (N=155) matched by year of diagnosis and health care unit. Univariate and multivariate analyses were conducted to test the associations and odds ratios and related 95% confidence intervals were estimated. RESULTS: The following factors were found to be significantly associated (p<0.05) with retreatment: occurrence of adverse immunological reactions after treatment completion (OR=2.3; 95% CI=1.18;4.83), final bacterial index > 1 (OR=6.43; 95% CI=1.67;24.74), therapeutic regimen consisting of sulfone monotherapy (OR=10; 95% CI=0.01;0.78) and reports of household contacts (OR=2.2; 95% CI=0.24;0.85). CONCLUSIONS: The study findings reinforce that the use of dapsone monotherapy should be discontinued, and highlight the need for epidemiological monitoring of specific groups of leprosy patients after treatment completion through periodical clinical and laboratory evaluation. Further studies to explore the association between final bacterial index and retreatment are strongly recommended.

Dietary patterns and risk of oral cancer: a case-control study in São Paulo, Brazil

OBJECTIVE: To analyze the association between dietary patterns and oral cancer. METHODS: The study, part of a Latin American multicenter hospital-based case-control study, was conducted in São Paulo, Southeastern Brazil, between November 1998 and March 2002 and included 366 incident cases of oral cancer and 469 controls, frequency-matched with cases by sex and age. Dietary data were collected using a food frequency questionnaire. The risk associated with the intake of food groups defined a posteriori, through factor analysis (called factors), was assessed. The first factor, labeled "prudent," was characterized by the intake of vegetables, fruit, cheese, and poultry. The second factor, "traditional," consisted of the intake of rice, pasta, pulses, and meat. The third factor, "snacks," was characterized as the intake of bread, butter, salami, cheese, cakes, and desserts. The fourth, "monotonous," was inversely associated with the intake of fruit, vegetables and most other food items. Factor scores for each component retained were calculated for cases and controls. After categorization of factor scores into tertiles according to the distribution of controls, odds ratios and 95% confidence intervals were calculated using unconditional multiple logistic regression. RESULTS: "Traditional" factor showed an inverse association with cancer (OR=0.51; 95% CI: 0.32; 0.81, p-value for trend 0.14), whereas "monotonous" was positively associated with the outcome (OR=1.78; 95% CI: 1.78; 2.85, p-value for trend <0.001). CONCLUSIONS: The study data suggest that the traditional Brazilian diet, consisting of rice and beans plus moderate amounts of meat, may confer protection against oral cancer, independently of any other risk factors such as alcohol intake and smoking.

Physical activity during pregnancy and fetal outcomes: a case-control study

OBJECTIVE: To investigate the relationship between physical activity during the second trimester pregnancy and low birth weight, preterm birth, and intrauterine growth restriction. METHODS: Case-control study including 273 low birth weight newborns and 546 controls carried out in the city of São Paulo, Southeastern Brazil, in 2005. Low birth weight cases were grouped into two subsamples: preterm birth (n=117) and intrauterine growth restriction (n=134), with their related controls. Information was collected by means of interviews with mothers shortly after birth and transcription of medical records. Data were analyzed using conditional multiple and hierarchical logistic regression. RESULTS: Light physical activity for over 7 hours per day was shown to be protective against low birth weight (adjusted OR=0.61; 95% CI 0.39-0.94) with a dose-response relationship (p-value for trend=0.026). A similar trend was found for intrauterine growth restriction (adjusted OR=0.51; 95% CI 0.26-0.97). Homemaking activities were associated as a protective factor for both low birth weight and preterm birth (p-value for trend=0.013 and 0.035, respectively). Leisure-time walking was found to be protective against preterm birth. CONCLUSIONS: Mild physical activity during the second trimester of pregnancy such as walking has an independent protective effect on low birth weight, preterm birth, and intrauterine growth restriction.

The AIDS epidemic in the Amazon region: a spatial case-control study in Rondonia, Brazil

OBJECTIVE To analyze spatial changes in the risk of AIDS and the relationship between AIDS incidence and socioeconomic variables in the state of Rondonia, Amazon region. METHODS A spatial, population case-control study in Rondonia, Brazil, based on 1,780 cases reported to the Epidemiological Surveillance System and controls based on demographic data from 1987 to 2006. The cases were grouped into five consecutive four-year periods. A generalized additive model was adjusted to the data; the dependent variable was the status of the individuals (case or control), and the independent variables were a bi-dimensional spline of the geographic coordinates and some municipality-level socioeconomic variables. The observed values of the Moran’s I test were compared to a reference distribution of values generated under conditions of spatial randomness. RESULTS AIDS risk shows a marked spatial and temporal pattern. The disease incidence is related to socioeconomic variables at the municipal level in Rondônia, such as urbanization and human capital. The highest incidence rates of AIDS are in municipalities along the BR-364 highway and calculations of the Moran’s I test show positive spatial correlation associated with proximity of the municipality to the highway in the third and fourth periods (p = 0.05). CONCLUSIONS Incidence of the disease is higher in municipalities of greater economic wealth and urbanization, and in those municipalities bisected by Rondônia’s main roads. The rapid development associated with the opening up of once remote regions may be accompanied by an increase in these risks to health.

Risk factors for recurrent wheezing in infants: a case-control study

ABSTRACT OBJECTIVE To evaluate the association between recurrent wheezing and atopy, the Asthma Predictive Index, exposure to risk factors, and total serum IgE levels as potential factors to predict recurrent wheezing. METHODS A case-control study with infants aged 6-24 months treated at a specialized outpatient clinic from November 2011 to March 2013. Evaluations included sensitivity to inhalant and food antigens, positive Asthma Predictive Index, and other risk factors for recurrent wheezing (smoking during pregnancy, presence of indoor smoke, viral infections, and total serum IgE levels). RESULTS We evaluated 113 children: 65 infants with recurrent wheezing (63.0% male) with a mean age of 14.8 (SD = 5.2) months and 48 healthy infants (44.0% male) with a mean age of 15.2 (SD = 5.1) months. In the multiple analysis model, antigen sensitivity (OR = 12.45; 95%CI 1.28–19.11), positive Asthma Predictive Index (OR = 5.57; 95%CI 2.23–7.96), and exposure to environmental smoke (OR = 2.63; 95%CI 1.09–6.30) remained as risk factors for wheezing. Eosinophilia ≥ 4.0% e total IgE ≥ 100 UI/mL were more prevalent in the wheezing group, but failed to remain in the model. Smoking during pregnancy was identified in a small number of mothers, and secondhand smoke at home was higher in the control group. CONCLUSIONS Presence of atopy, positive Asthma Predictive Index and exposure to environmental smoke are associated to recurrent wheezing. Identifying these factors enables the adoption of preventive measures, especially for children susceptible to persistent wheezing and future asthma onset.

Clinical and laboratory findings of disseminated Mycobacterium avium complex infection (DMAC) in a pair matched case-control study

A pair matched case/control study was conducted from January 1991 to 30 June 1992 in order to define clinical and laboratory findings associated with DMAC infection in AIDS patients. Since DMAC infection is usually associated with advanced immunodeficiency, and therefore also with other opportunistic illnesses, in addition to the number of CD4+ lymphocytes, cases and controls were matched using the following criteria: date of AIDS diagnosis and antiretroviral therapy, number and severity of associated opportunistic infections and, whenever possible, type of Pneumocystis carinii prophylaxis, age and gender, in this order of relevance. Cases (defined as patients presenting at least one positive culture for MAC at a normally sterile site) and controls presented CD4+ lymphocyte counts below 50 cel/mm3. A significantly higher prevalence of general, digestive and respiratory signs, increased LDH levels, low hemoglobin levels and CD4+ cell counts were recorded for cases when compared to controls. Increases in gGT and alkaline phosphatase levels seen in cases were also recorded for controls. In conclusion, the strategy we used for selecting controls allowed us to detect laboratory findings associated to DMAC infection not found in other advanced immunossupressed AIDS patients without DMAC.

Identification of risk factors for death from tetanus in Pernambuco, Brazil: a case-control study

A case-control study was conducted to identify risk factors for death from tetanus in the State of Pernambuco, Brazil. Information was obtained from medical records of 152 cases and 152 controls, admitted to the tetanus unit in the State University Hospital, in Recife, from 1990 to 1995. Variables were grouped in three different sets. Crude and adjusted odds ratios, p-values and 95% confidence intervals were estimated. Variables selected in the multivariate analysis in each set were controlled for the effect of those selected in the others. All factors related to the disease progression - incubation period, time elapsed between the occurrence of the first tetanus symptom and admission, and period of onset - showed a statistically significant association with death from tetanus. Similarly, signs and/or symptoms occurring on admission or in the following 24 hours (second set): reflex spasms, neck stiffness, respiratory signs/symptoms and respiratory failure requiring artificial ventilation (third set) were associated with death from tetanus even when adjusted for the effect of the others.

A retrospective evaluation of a score system adopted by the Ministry of Health, Brazil in the diagnosis of pulmonary tuberculosis in childhood: a case control study

Based on a retrospective case-control study we evaluated the score system adopted by the Ministry of Health of Brazil (Ministério da Saúde - MS), to diagnose pulmonary tuberculosis (PTB) in childhood. This system is independent of bacteriological or histopathological data to define a very likely (> or = 40 points), possible (30-35 points) or unlikely (< or = 25 points) diagnosis of tuberculosis. Records of hospitalized non-infected HIV children at the Instituto de Puericultura e Pediatria Martagão Gesteira of Federal University of Rio de Janeiro (IPPMG-UFRJ), were reviewed. Patients were adjusted for age and divided in two different groups: 45 subjects in the case group (culture-positive) [mean of age = 10.64 mo; SD 9.66]; and 96 in the control group (culture-negative and clinic criteria that dismissed the disease) [mean of age = 11.79 mo.; SD 11.31]. Among the variables analyzed, the radiological status had the greater impact into the diagnosis (OR = 25.39), followed by exposure to adult with tuberculosis (OR = 10.67), tuberculin skin test >10mm (OR = 8.23). The best cut-off point to the diagnosis of PTB was 30 points, where the score system was more accurate, with sensitivity of 88.9% and specificity of 86.5%.

Lymph scrotum: an unusual urological presentation of lymphatic filariasis. A case series study

Lymphatic filariasis (LF) causes a wide range of clinical signs and symptoms, including urogenital manifestations. Transmission control and disability/morbidity management/control are the two pillars of the overall elimination strategy for LF. Lymph scrotum is an unusual urological clinical presentation of LF with important medical, psychological, social and economic repercussions. A retrospective case series study was conducted on outpatients attended at the National Reference Service for Filariasis, in an endemic area for filariasis (Recife, Brazil), between 2000 and 2007. Over this period, 6,361 patients were attended and seven cases with lymph scrotum were identified. Mean patient age was 45 years (range, 26 to 64 years). Mean disease duration was 8.5 years (range, two to 15 years). All patients had evidence of filarial infection from at least one laboratory test (parasitological, antigen investigation or "filarial dance sign" on ultrasound). Six patients presented histories of urological surgery. The authors highlight the importance of the association between filarial infection and the inadequate surgical and clinical management of hydrocele in an endemic area, as risk factors for lymph scrotum. Thus, filarial infection should be routinely investigated in all individuals presenting urological morbidity within endemic areas, in order to identify likely links in the transmission chain.

Diagnosing visceral leishmaniasis and HIV/AIDS co-infection: a case series study in Pernambuco, Brazil

HIV/AIDS-associated visceral leishmaniasis may display the characteristics of an aggressive disease or without specific symptoms at all, thus making diagnosis difficult. The present study describes the results of diagnostic tests applied to a series of suspected VL cases in HIV-infected/AIDS patients admitted in referral hospitals in Pernambuco, Brazil. From a total of 14 eligible patients with cytopenias and/or fever of an unknown etiology, and indication of bone marrow aspirate, 10 patients were selected for inclusion in the study. Diagnosis was confirmed by the following examinations: Leishmania detection in bone marrow aspirate, direct agglutination test, indirect immunofluorescence, rK39 dipstick test, polymerase chain reaction and latex agglutination test. Five out of the ten patients were diagnosed with co-infection. A positive direct agglutination test was recorded for all five co-infected patients, the Leishmania detection and latex agglutination tests were positive in four patients, the rK39 dipstick test in three, the indirect immunofluorescence in two and a positive polymerase chain reaction was recorded for one patient. This series of cases was the first to be conducted in Brazil using this set of tests in order to detect co-infection. However, no consensus has thus far been reached regarding the most appropriate examination for the screening and monitoring of this group of patients.

Case-control study of an outbreak of acute toxoplasmosis in an industrial plant in the state of São Paulo, Brazil

Foodborne diseases represent operational risks in industrial restaurants. We described an outbreak of nine clustered cases of acute illness resembling acute toxoplasmosis in an industrial plant with 2300 employees. These patients and another 36 similar asymptomatic employees were diagnosed with anti-T. gondii IgG titer and avidity by ELISA. We excluded 14 patients based on high IgG avidity and chronic toxoplasmosis: 13 from controls and one from acute disease other than T. gondii infection. We also identified another three asymptomatic employees with T.gondii acute infection and also anti-T. gondii IgM positive as remaining acute cases. Case control study was conducted by interview in 11 acute infections and 20 negative controls. The ingestion of green vegetables, but not meat or water, was observed to be associated with the incidence of acute disease. These data reinforce the importance of sanitation control in industrial restaurants and also demonstrate the need for improvement in quality control regarding vegetables at risk for T. gondii oocyst contamination. We emphasized the accurate diagnosis of indexed cases and the detection of asymptomatic infections to determine the extent of the toxoplasmosis outbreak.

Analysis of urban land use and land cover changes: a case of study in Bahir Dar, Ethiopia

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies

Environmental sanitation conditions and health impact: a case-control study

This epidemiological investigation examines the impact of several environmental sanitation conditions and hygiene practices on diarrhea occurrence among children under five years of age living in an urban area. The case-control design was employed; 997 cases and 999 controls were included in the investigation. Cases were defined as children with diarrhea and controls were randomly selected among children under five years of age. After logistic regression adjustment, the following variables were found to be significantly associated with diarrhea: washing and purifying fruit and vegetables; presence of wastewater in the street; refuse storage, collection and disposal; domestic water reservoir conditions; feces disposal from swaddles; presence of vectors in the house and flooding in the lot. The estimates of the relative risks reached values up to 2.87. The present study revealed the feasibility of developing and implementing an adequate model to establish intervention priorities in the field of environmental sanitation.