Search PubMed⌕ Search

Biomedical subjects

Oswaldo Paulo Forattini

Publications and source records attributed to Oswaldo Paulo Forattini.

15 recordsLinked to original sources
PubMed2006

[Biogeography, origin, and distribution of triatominae domiciliarity in Brazil. Revista de Saúde Pública, 14(3):265-99, 1980].

An association is established between the Brazilian geographical pattern of the domiciliarity of the triatominae bugs and open lands characterized by natural savanna vegetation or artificial, man-made landscapes. The Brazilian open lands involved are the "caatingas'' and "cerrados", both wholly included in Brazilian territory, while the mixed Southern subtropical prairies belong to systems extending bevond national boundary lines. The other open lands are anthropic-lands opened mainly by the destruction of primitive forests of the tropical Atlantic system. Attempts were made to subject the four synanthropic species of epidemiological importance to model paleoecologic refuges and endemic centers. Triatoma sordida, Triatoma brasiliensis, and Triatoma pseudomaculata seem to have their endemic centers in the "cerrados" and "caatinga", while the Panstrongylus megistus may have originated in the tropical Atlantic forest system. The Triatoma infestans, however, seem to have originated in Bolivia, then were spread to large dispersal regions by man. Thus it can be assumed that domiciliarity is arrived at through an opportunistic mechanism stimulated by shelter and food availability factors. Once established, domiciliarity favors the species survival and dispersal, and this is of particular interest to control and surveillance programs because it increases the probability of the triatominae's success in synanthropic specialization. The present intense anthropic activities in the Amazonian system will lead to even greater expansion into the open lands; consequently, a triatominae domiciliarity spread can be expected, due to either autochthonous or man-introduced populations. A public health problem will then arise in a region where it has, heretofore, been unknown.

Animals↗
PubMed2005

Karyotype of Brazilian Anopheles albitarsis sensu lato (Diptera:Culicidae).

Anopheles (Nyssorhynchus) albitarsis sensu lato is an important malaria vector in Brazil, especially in the Brazilian Amazon region. Chromosome preparations of fourth-instar larvae of A. albitarsis from Iranduba and Coari (AM) and Ilha Comprida (SP) were analyzed for karyotype determination and to improve cytogenetic identification of this species. Anopheles albitarsis possesses 2n = 6 chromosomes, with two pairs (submetacentric and metacentric) of autosomes and one pair of sex chromosomes, with X-Y dimorphism. The sex pair is homomorphic and acrocentric in females and heteromorphic in males, with a punctiform Y chromosome. Somatic pairing was detected in the prometaphase and metaphase chromosomes of the three A. albitarsis populations. Apparently, sex chromosome evolution in the Culicidae does not function as does evolution in the Culicidae, since it occurs in the subfamily Anophelinae, which possesses heteromorphic sex chromosomes and is regarded as primitive, based on several criteria. These karyotype data on the albitarsis complex reinforce the hypothesis that sex chromosome evolution in the subfamily Anophelinae is conserved, and the variation revealed in the mean size of chromosomes in three populations indicates that selective pressure in these populations is occurring only at a genetic level.

Animals↗
PubMed2005

[Aedes albopictus in soil bromeliads in Ilhabela, coastal area of Southeastern Brazil].

OBJECTIVE: To analyze the presence of Aedes albopictus in soil bromeliads in ecologically distinct environments in terms of positivity, density and volume of water. METHODS: The study was carried out in the municipality of Ilhabela, North coast of the state of São Paulo, Brazil. Collections were fortnightly performed between March 1998 and July 1999, in containers of bromeliads located in urban, peri-urban and forest environments. The water content in plants was measured and recorded. Data analysis was based on the frequency of bromeliads with Ae. albopictus (ANOVA), abundance (Kruskal-Wallis) and volume of water in positive bromeliads (Student's t-test). RESULTS: The presence and density of Ae. albopictus in soil bromeliads varied by environment. Greater positivity (85%) and abundance (81%) were found in plants located in the urban environment. Also, mosquitoes showed preference to bromeliads with higher content of water (mean 300 ml). CONCLUSIONS: The different frequencies and densities of Ae. albopictus seen in the different environments show their capacity of invading new habitats. It is advisable to intensify entomologic surveillance in these plants as they could become permanent breeding sites. The presence of these mosquitoes of medical importance in bromeliads in a preserved area of the Atlantic Rainforest may imply in serious health hazard.

Aedes↗
PubMed2004

[Productivity of Aedes albopictus' breeding containers in Paraíba Valley, Brazil].

OBJECTIVE: To estimate the potential productivity of artificial, permanent, and natural breeding containers of Aedes albopictus, potential vector species of dengue. METHODS: Three locations were selected for this study: a) warehouse of disposable material goods in the urban area of Pindamonhangaba, state of São Paulo, Brazil; b) a small leisure farmland in Tremembé, state of São Paulo; and c) residual forest in the periurban area of Pindamonhangaba. All breeding containers were assessed and classified according to their water volume ( small (up to 1 liter), medium (over 1 but up to 10 liters), and large (over 10 liters), and type (artificial, natural, and permanent). Collections were carried out fortnightly for a period of 12 months, and a sample of fourth-instar larvae and pupae were collected from each container. Statistical analysis was performed using the Kriskal-Wallis test, t-Student test, and emergence estimate. RESULTS: The statistical analyses and emergence estimate (E) showed that artificial large-size containers and permanent medium container were on average the most productive, resulting 2.8 females a day, each. Natural small and medium containers produced on average 0.5 and 0.6 females respectively. CONCLUSIONS: There is a need for further studies on the potential productivity of containers not only of Ae. albopictus but also of Aedes aegypti, the main vector of dengue, which could contribute to better assessments of population densities in surveillance and control programs.

Aedes↗
PubMed2004

Susceptibility of urban and rural populations of Aedes albopictus from São Paulo State, Brazil, to infection by dengue-1 and -2 viruses.

In Brazil, dengue viruses (DENV) are transmitted by Aedes aegypti (L.). However, the recent introduction of Aedes albopictus (Skuse) has caused concern, because some populations of this species also are capable of DENV transmission. Ae. albopictus from rural and urban localities of São Paulo State, Brazil, were artificially exposed to infection with DENV-1 and -2 to evaluate their susceptibility. The rates of infection (6.2 and 5.7% for DENV-1; 5.3 and 12% for DENV-2) and dissemination (22.2 and 40% for DENV-1; 0 and 20% for DENV-2) were low in both urban and rural populations, with no significant differences detected between these mosquito populations.

Aedes↗
PubMed2004

Anopheles albitarsis s.l. (Diptera: Culicidae) survivorship and density in a rice irrigation area of the state of São Paulo, Brazil.

Collections of Anopheles albitarsis Arribalzaga s.l. were conducted from May 1996 to June 2000 to estimate the human biting rate, and mark-release-recapture experiments were carried out to estimate the daily survival probability. The density of An. albitarsis females showed a marked seasonal variation, with peaks as high as 629 individuals per human per night in the wet season. The low daily survival probability of 0.61 is an important factor limiting the vectorial capacity of An. albitarsis s.l. in southeastern Brazil.

Animals↗
PubMed2003

[Household water reservoirs and control of Aedes aegypti].

Water reservoirs for domestic use are important sites for the development of Aedes aegypti. In poor areas, these reservoirs are often located outdoors upon flat rooftops. In modern architecture buildings, however, the same is seen even in high-class condominiums. Special attention should be given to these modern architectural constructions during entomological surveillance.

Aedes↗
PubMed2003

[Parity and wind impact on the frequency of Anopheles marajoara, São Paulo, Brazil].

OBJECTIVE: To evaluate the impact of wind velocity on the behavior of An. marajoara population and its parity. METHODS: Collections were made bimonthly from January 1999 to February 2000 in the municipality of Ilha Comprida, Brazil. Adult mosquitoes were captured with a battery hand aspirator. Mann-Whitney test was applied to verify the wind impact on mosquito behavior. Polovodova technique and Christophers and Mer's follicular development analysis were used to determine parity. RESULTS: A total of 11,833 mosquitoes were captured, including 3,072 An. marajoara specimens. The peak of activity of An. marajoara occurred from 2 to 5 AM. Amongst 1,006 An. marajoara females who had their ovarioles dissected, it was found 530 (52.7%) nulliparous, 432 (42.9%) uniparous, 24 (2.4%) biparous and 1 multiparous. According to Christophers and Mer analysis, 982 (97.6%) had their follicles in phases I and II, 7 in phases III and IV, and 17 in phase V. The frequency of An. marajoara was significantly lower when wind velocity was 3 km/h or more or below 3 km/h. CONCLUSIONS: An. marajoara mosquitoes were more active at night. About 50% of dissected An. marajoara females were oniparous. Another important finding was the high proportion of females (97.6%) with follicles in the Christophers and Mer's phases I and II, suggesting the presence of gonotrophic concordance. Wind velocity equal or higher than 3 km/h considerably reduced the frequency of An. marajoara.

Aedes↗
PubMed2003

[Survival of Aedes albopictus: physiological age and reproductive history].

OBJECTIVES: To study the longevity of Ae. albopictus populations in rural and urban areas in two different feeding conditions and to assess their physiological age and reproductive history. METHODS: Ae. albopictus larvae were collected in the Para ba Valley, (urban area) and Ribeira Valley (rural area), S o Paulo State, Brazil. In the laboratory, females were fed with sugar or blood and monitored daily. The day of death of each mosquito and other reproduction related characteristics were registered. Ovaries were dissected using Polovodova techniques and follicular development was examined according Christophers and Mer. Life tables were created and statistics analysis was performed for survival rates. Data analysis was carried out using Stata 7.0. RESULTS: Gonotrophic discordance was seen in both populations. Parous females developed terminal sacs. Nulliparous females had normal ovaries and in some cases dilatations were seen. Females fed with sugar showed higher survival rates. Statistical difference in survival rates was not observed in the populations of both areas. CONCLUSIONS: Parity status and physiological age of Ae. albopictus were not described using ovarioles analysis because they formed terminal sacs instead of dilations. Longevity of Ae. albopictus females was influenced by the food provided.

Aedes↗
PubMed2003

Systematic studies on Anopheles galvaoi Causey, Deane & Deane from the subgenus Nysssorhynchus blanchard (Diptera: Culicidae).

Anopheles galvaoi, a member of the subgenus Nyssorhynchus, is redescribed based on morphological characters of the adults male and female, fourth-instar larva and pupa. Female, male genitalia, larval and pupal stages are illustrated. Data about medical importance, bionomics, and distribution are given based on literature records. Adult female of An. galvaoi can be easily misidentified as An. benarrochi Gabald n and An. aquasalis Curry. A few characters are indicated for identifying female and immatures of An. galvaoi. Phylogenetic relationships among An. galvaoi and six other species of the Oswaldoi Subgroup are estimated using COII mtDNA and ITS2 rDNA gene sequences. Lectotype of An. galvaoi, an adult female from Rio Branco, State of Acre, is invalidated.

Animals↗
PubMed2002

[Evolutionary epidemiological thought on infections].

The objective of the study is to analyse the main aspects of current epidemiological knowledge on the evolutionary status of infections. Living organisms in the biosphere are part of dynamic systems of variable intensities. Some of these systems are on the surface while others take place inside the genome core. Parasitism is a phenomenon commonly seen in nature. Infective parasites relate to each other through several mechanisms, such as genetic DNA exchange, and because of the connections established communities of infectious agents are not isolated. The internalization process allows the parasites to get into their hosts' cells, which is accomplished through the phagocytosis of infectious agents or other more sophisticated mechanisms such as pill production. To leave the intracellular medium, some organisms make use of apoptosis, a highly specialized genetic mechanism that makes possible to destroy macrophages. It is currently accepted that molecular DNA can flow into the blood stream as the so-called infectrons. Thus it is hypothesized the existence of infection networks that allows the coadaptability of parasites and their hosts, and creates coevolutionary forces between hosts and their parasites facilitating the emergence of new pathogens.

Adaptation, Biological↗
PubMed2002

[Vaccine again].

Explore the source record for details and available documents.

Humans↗
PubMed2002

Laboratory and field observations on duration of gonotrophic cycle of Anopheles albitarsis s.l. (Diptera: Culicidae) in southeastern Brazil.

Mark-release-recapture experiments were conducted to determine the duration of the gonotrophic cycle of Anopheles albitarsis s.l. in Ribeira Valley, State of Sao Paulo, Brazil. Separate experiments with females collected from the field were followed under laboratory conditions. A mean of 2.4 d was characteristic for the gonotrophic cycle for wild-caught females, whereas 4.4 d was characteristic for females in the laboratory conditions.

Animals↗
PubMed2002

The eggs of Anopheles galvaoi and Anopheles evansae, two species of the subgenus Nyssorhynchus.

The ultrastructure of the eggs of Anopheles (Nyssorhynchus) galvaoi Causey, Deane, and Deane and Anopheles (Nyssorhynchus) evansae (Brethes) are described and illustrated with scanning electron micrographs. The eggs of these species are similar to those of Anopheles (Nyssorhynchus) aquasalis Curry, Anopheles (Nyssorhynchus) oswaldoi (Peryassu), and Anopheles (Nyssorhynchus) konderi Galvão and Damasceno in having floats long, widely joined posteriorly on the dorsal surface, the frill encircling the anterior end of the egg, and the crown absent. A few distinctive characters to distinguish An. evansae from An. galvaoi are given.

Animals↗