Biomedical subjects

E Massad

Publications and source records attributed to E Massad.

At least 55 records · Page 3Linked to original sources

PubMed1996

HIV and infections of similar transmission patterns in a drug injectors community of Santos, Brazil.

To study the prevalence of HIV and infections with related transmission patterns, we interviewed and obtained blood samples from 220 injecting drug users (IDUs), sampled by snowballing, from the city of Santos in the state of São Paulo, Brazil, where the estimated number of IDUs (10,000) comprises approximately 2% of the entire population. Seroprevalence of HIV, hepatitis B and C, syphilis, and HTLV (1 and 2) was assessed and compared with that in 197 blood donors from the same city, matched for age and gender. Risk behavior related to HIV was assessed by a standard questionnaire applied to the IDU sample. Univariate and multivariate analyses of the risk factors were performed. Seroprevalences found were 62% for HIV, 75% for HCV, 75% for HBV, 34% for syphilis, and 25% for HTLV (1 and 2) among IDUs, which compare with 0.0%, 2%, 23%, 12%, and 1% for blood donors, respectively. The risk for parenterally transmitted infections in this IDU community was higher than that for sexually transmitted infections (odds ratio for syphilis, 3.57; hepatitis B, 10.0; and hepatitis C, 100). The results of the mutivariate risk analysis showed that daily rate of ID use >5 times/day (OR = 6.73), not changing behavior to avoid AIDS (OR= 3.28), ID use >15 days/month (OR = 2.72), and ID use in the last 2 months (OR = 2.23) were the risk behaviors significantly associated with HIV infection.

Adolescent↗

PubMed1996

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 11--Biting activity and blood-seeking parity of Anopheles (Kerteszia) in south-eastern Brazil.

An. (Ker.) cruzii and An. (Ker.) bellator were monitored by the use of human bait and Shannon trap collections during a one-year period in 1994. Indoor and outdoor collections were made on human bait and inside the forest environment a Shannon trap was used. Both were undertaken in the evening crepuscular period. Results showed a greater abundance of An. cruzii in the forest, where as An. bellator was more abundant in the domiciliary environment. Through the application of the Polovodova method an age grading was established. Computing the parous and nulliparous females with Christopher's Stage III and above, more than 30.0% of blood-seeking specimens of both anophelines had had a previous blood meal. The higher abundance of An. bellator as compared with that of An. cruzii in the domiciliary environment may be explained by the influence of the neighboring low-lying coastal islands of the estuary system.

Animals↗

PubMed1996

Studies on mosquitoes (Diptera:Culicidae) and anthropic environment. 12-host-seeking behaviour of Anopheles albitarsis s.l. in south-eastern Brazil.

Results obtained with Anopheles albitarsis s.l. catches mainly performed through human bait at the Ribeira Valley region, SP (Brazil), are reported. Two species of the complex were recognized, namely An. albitarsis s.s. and species B. This latter predominated both in the rice fields and in the dwelling environments. The crepuscular rhythms showed an unimodal sunset pattern with most blood-seeking females caught during dusk. The absence of differences between indoor and outdoor behavior was confirmed for both species of the complex.

Animals↗

PubMed1995

Assessing the efficacy of a mixed vaccination strategy against rubella in São Paulo, Brazil.

BACKGROUND: In 1992 a major vaccination strategy against measles-mumps-rubella was introduced in the State of Saão Paulo, Brazil. This strategy was based on mathematical models and comprised a pulse vaccination covering all children aged 1-10 years, followed by the inclusion of this vaccine in the routine calendar at 15 months of age. The present work reports the evaluation of the efficacy of this mixed vaccination strategy. METHODS: A rubella seroprevalence survey was carried out immediately and one year after the campaign, comprising 4953 children aged 1-15 years. RESULTS: We show that average rubella seroprevalence increased from 0.40 to 0.97 and that the reported number of congenital rubella syndrome (CRS) cases dropped dramatically. CONCLUSIONS: The mixed vaccination strategy adopted against rubella has proved to be very effective in reducing the number of CRS cases in São Paulo.

Adolescent↗

PubMed1995

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 7-behaviour of adults Nyssorhynchus anophelines with special reference to Anopheles albitarsis s.l. in south-eastern Brazil.

Results obtained with catches performed at several sites of the Ribeira Valley, SP (Brazil) are reported. Collections with Shannon type traps showed a concentration of An.albitarsis s.l. in the Experimental Farm of Pariquera-Açu County, associated with the development of irrigated rice cultivation. Two species of the complex, named A and B, were recognized. Species B predominated in the samples. Indoor and outdoor crepuscular human bait captures were performed a the domiciliary environment. The two species showed a generally low William's media valve of 0.2, the highest value obtained was 1.6. No differences were found between indoor and outdoor behaviours between the two species of the complex.

Animals↗

PubMed1995

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 8--Survey of adult behaviour of Spissipes Section species of Culex (Melanoconion) in south-eastern Brazil.

A study of Spissipes Section of Culex (Melanoconion) adults behaviour was carried out from August 1992 through December 1993 in human dominated (anthropic) environment in the Ribeira Valley, S. Paulo State, Brazil. By sampling at several sites it the dominance of Culex ribeirensis and Cx. sacchettae became evident even through a total number of ten species was recorded. Those two mosquitoes showed a clear tendency to frequent the domiciliary environment where they were caught, both indoor and outdoor, through the use of the human bait. In the outside environments, the residual patchy forests seems to display a concentration role, from which these adults spread to the open land and reach the dwellings. As their vector competence has been demonstrated through the virus isolations in natural conditions, it is advisable to pay attention to the presence of these mosquitoes in the man-made environment.

Animals↗

PubMed1995

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 9-Synanthropy and epidemiological vector role of Aedes scapularis in south-eastern Brazil.

Behaviour comparisons of Aedes scapularis and Ae. serratus are presented. Results were obtained by sampling Aedes adult mosquitoes at several places in the rural anthropic environment in the Ribeira Valley region of S. Paulo State, Brazil. Aedes dominance was shared by those two species, but Ae. scapularis showed a clear tendency to frequent the modified environment, while Ae. serratus was to be found in the more preserved ones, here represented by the vestigial patchy forests. Regarding the open cultivated land and the dwelling environments, Ae. scapularis preponderates. Considering the regional development phases, this mosquito showed a remarkable increase in the modified environment differently from Ae. serratus that underwent a considerable decrease in migrating from the forest to the anthropic environment. As a consequence of these results it is reasonable to conclude that Ae. scapularis may be considered as an epidemiologically efficient vector and that it quite probably played this role in the Rocio encephalitis and other arbovirus epidemics.

Aedes↗

PubMed1995

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 10- Survey of adult behaviour of Culex nigripalpus and other species of Culex (Culex) in south-eastern Brazil.

A survey of adult behaviour of Culex (Culex) species was carried out from August 1992 through December 1993 in a human modified (anthropic) environment in the Ribeira Valley, S. Paulo State, Brazil. Culex nigripalpus dominated the catches at several sites and it's tendency to increase in the anthropic environment became quite clear. Nevertheless no high level of synanthropy was demonstrated. So it seems that the mosquito may have a restricted role in natural arbovirus cycles. Nonetheless, Cx. nigripalpus must be considered a potential vector of arboviruses, especially St. Louis encephalitis virus outside dwellings.

Animals↗

PubMed1995

[Mortality trends due to myocardial ischemia in capital cities of the metropolitan areas of Brazil, 1979-89].

PURPOSE: To study the trends of mortality rates from cardiovascular diseases (CVD) and coronary heart disease (CHD) in eight capitals of Brazil. METHODS: Death rates for these cities were studied in men (M) and female (F), standardized using the population of São Paulo, SP, 1980. Rates were calculated for CVD (ICD-9: 390-459) and CHD (ICD-9:410-414). The cities were Belém, Recife, Salvador, Belo Horizonte, Rio de Janeiro, São Paulo, Curitiba and Porto Alegre. Using simple linear regression, we obtained the annual difference in rates with a confidence interval of 95%. RESULTS: For CVD a decline was detected of -2.6% (M) and -2.69% (F) in Belém; in Salvador, -1.53% (M) and -1.70% (F) and in São Paulo, -1.27% (M) and -1% (F) and for F in Belo Horizonte (-0.82%) and in Curitiba (-1.52%). Recife, Porto Alegre and Curitiba (M) showed stability during the period. There was a rise of the rates in Rio de Janeiro +1.37% (M) and +0.84% (F) and for M in Belo Hozironte (1%). The rates for CHD showed a decline in Belém-2.64% (M) and -2.74% (F); São Paulo, -1.4% (M) and -1.06% (F) and for F in Belo Horizonte. A stable trend was detected in Salvador, Curitiba, Porto Alegre and for M in Belo Horizonte. There was a rise in the rates of Recife +3.5% (M) and +4.4% (F) and in Rio de Janeiro +2.34% (M) and +2.53% (F). CONCLUSION: The magnitude of death rates and of the time trends showed in this paper reveal important regional differences. Questions related to the different assignment of diagnosis in the chapter of CVD could explain some of the observed trends. However, the rise of mortality rates in Rio de Janeiro could hardly be explained by classificatory matters. Tobacco, diet and medical care could explain the rise of mortality from CVD and CHD in Rio de Janeiro.

Adult↗

PubMed1994

A case-control study of histological chorioamnionitis and neonatal infection.

The authors report a prospective study of the correlation between histopathological alterations in the placenta and the umbilical cord and neonatal infection in 223 newborns. The pathological studies were specifically concerned with the presence of infection as shown by a polymorphonuclear infiltrate at these sites. Inflammatory lesions were demonstrated in 26.9% of specimens and were highest in those with prolonged premature rupture of membranes and in the least mature placentas. Among the cases of histological chorioamnionitis, only 23.3% of infants had documented infection. Neonatal infection was diagnosed in 7.2% of the newborns and was 10 times more frequent in preterm newborns. Among the cases of infected newborns, 87.5% of placentas had histological chorioamnionitis. Pneumonia and septicemia were the most frequent conditions found among infected newborns. There was a strong correlation between histological chorioamnionitis and neonatal infection. The data obtained in this investigation suggest that histological chorioamnionitis is an important indicator of neonatal infection.

Anti-Bacterial Agents↗

PubMed1994

Association between air pollution and mortality due to respiratory diseases in children in São Paulo, Brazil: a preliminary report.

This work presents the results of a time series study relating air pollution and respiratory mortality in children under 5 years of age in the metropolitan area of São Paulo, Brazil. Daily records of mortality (excluding neonatal mortality) for the period May 1990 to April 1991 were collected along with daily records of relative humidity, temperature, SO2, CO, particulates (PM10), O3, and NOx concentrations. Using multiple regression methods we demonstrated a significant association between mortality due to respiratory diseases and the NOx levels. After controlling for weather and season effects, the odds of dying due to respiratory diseases, considering the mean levels of NOx in São Paulo, was estimated at 1.3 (+/- 0.13). This result is in accord with previous animal studies conducted by our group and indicates that air pollution in São Paulo has reached levels high enough to have adverse health effects on the exposed population.

Air Pollution↗

PubMed1994

The basic reproduction ratio of HIV among intravenous drug users.

A new approach for the estimation of the Basic Reproduction Ratio R0 for HIV among intravenous drug users (IVDU) is proposed. This approach is based in an adaptation of the models proposed by Ross and Macdonald for vector-borne infections. A straightforward adaptation of Macdonald's model is presented first: biological vectors are replaced by needles and syringes and we consider a homogeneous population of IVDUs; next we present a modified model where several heterogeneities are considered. Some of those heterogeneities are due to intrinsic differences between needles and syringes and biological vectors; others, such as those related to movements of individuals between communities, should apply to both biological vectors and injection apparatuses. An example of the calculations of R0 for a real IVDUs community is presented.

Animals↗

PubMed1994

A model-based design of a vaccination strategy against rubella in a non-immunized community of São Paulo State, Brazil.

A mixed vaccination strategy against rubella is proposed. We describe how the vaccination strategy was designed with the help of mathematical techniques. The strategy was designed for application in a non-immunized community of the State of São Paulo, Brazil, and was implemented by local health authorities in 1992. This strategy comprises a pulse vaccination campaign, covering the age interval between 1 and 10 years, followed by the introduction of the vaccine in the immunization calendar at 15 months of age. The expected impact of the proposed strategy is discussed.

Adolescent↗

PubMed1994

Rubella seroepidemiology in a non-immunized population of São Paulo State, Brazil.

A rubella serological survey of 476 individuals selected by cluster sampling technique from Caieiras, a small town located in the outskirts of São Paulo city, southeastern Brazil, was carried out over the period November 1990-January 1991. The aim of the study was to characterize rubella epidemiology in a representative non-immunized community in south east Brazil. The survey comprised a seroprevalence study, stratified by age (0-40 years) and a seroconversion study of rubella vaccine in non-infected children below 2 years of age. Mathematical techniques were applied to resultant data sets to determine the age dependent rates of decay in the proportion of individuals with maternally derived antibodies, vaccine seroconversion, and infection of susceptibles, termed the force of infection, and to estimate the average age at first infection.

Adolescent↗

PubMed1994

[Neuropsychological tests of simple application for diagnosing dementia].

Thirty patients with dementia defined by DSM-III-R criteria (Alzheimer's disease (22), vascular dementia (3), Parkinson's disease, frontal lobe dementia, possible diffuse Lewy body dementia, normal pressure hydrocephalus and uncertain diagnosis), with scores below 24 points in the Mini-Mental Status Examination and more than 4 years of education were submitted to a neuropsychological evaluation. The scores in the neuropsychological tests were compared to those obtained by thirty normal volunteers paired for age, sex and education. Sensitivity, specificity and accuracy of the tests in the distinction of demented and normal volunteers were determined. The accuracies were calculated using ROC curves. Blessed's information-memory-concentration test showed greatest accuracy, followed by copy of simple figures, delayed memory of 10 figures (after 5 minutes), recognition of 10 figures and verbal fluency test (animals). A linear discriminant function, composed by 6 tests: visual perception, incidental memory, delayed memory (after 5 minutes), drawing of a clock, verbal fluency (animals) and calculation tests, was able to discriminate all controls from patients and only one patient was wrongly classified as normal control. These tests were chosen because they can be applied in less than 10 minutes and are very easy to interpret. This discriminant function must be applied in another group of patients and controls in order to demonstrate its value. When associated to the MMSE it may be useful to discriminate patients with dementia from normal people in epidemiological studies.

Age Distribution↗

PubMed1994

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 5--breeding of Anopheles albitarsis in flooded rice fields in south-eastern Brazil.

Studies on breeding Anopheles albitarsis and association with rice growth in irrigated paddy fields were carried out during the rice cultivation cycle from December 1993 to March 1994. This period corresponded to the length of time of permanent paddy flooding. Breeding occurred in the early stage up until five weeks after transplantation when rice plant height was small. That inverse correlation may give potential direction to control measures.

Agriculture↗

PubMed1994

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment. 6--Breeding in empty conditions of rice fields in south-eastern Brazil.

Studies on culicid breeding in empty rice fields were carried out during the cultivation cycle from May to November 1993. This period corresponded to stages 1 and 2, when empty conditions prevailed. Breeding occurred in stage 1 and the first part of stage 2, corresponding respectively to fallow uncultivated and ploughing situations. No breeding was found to take place during the second part of stage 2 when transient floods and harrowing occurred. The predominant species were Aedes scapularis, Culex nigripalpus and Cx. mollis. The Pilosus Group of Culex (Melanoconion) was found at lower densities. Some epidemiological considerations are presented.

Agriculture↗

PubMed1993

Modeling and simulating the evolution of resistance against antibiotics.

An epidemiological model is proposed for the spread of resistance against antibiotics in populations of bacterial pathogens. The host population, which is assumed to be constant, is divided into three compartments, viz. susceptible, hosts infected by an antibiotic-sensitive strain and hosts infected by a resistant strain. It is further assumed that susceptibles can be infected by either strain and that there is a possibility for cross-infection between hosts infected by the two strains. The rate of cross-infection can be enhanced by mutations or the transfer of plasmids conferring resistance. Equilibrium analysis was performed in order to determine which of the strain 'wins' the competition by the host. It is assumed that the eventual shift in the competition between the two strains is due to treatment by antibiotic (selective pressure).

Amikacin↗