Seasonality of Lutzomyia intermedia and Lutzomyia whitmani (Diptera: Psychodidae: Phlebotominae), occurring sympatrically in area of cutaneous leishmaniasis in the State of Rio de Janeiro, Brazil

Lutzomyia intermedia and Lutzomyia whitmani occur sympatrically in the district of Posse, municipality of Petrópolis, in the State of Rio de Janeiro (114 km from the city of Rio de Janeiro), where sand flies were captured weekly for three consecutive years in both the peridomicile and forest, in two first years from 18:00 to 22:00 h, using a Shannon trap and CDC light traps. The anthropophilic habit was assessed by recording the specimens that bit the human captors. Considering the different capture types and sites, the following species were identified: Brumptomyia brumpti, B. cardosoi, B. guimaraesi, Lutzomyia amarali, L. longipalpis, L. microps, L. costalimai, L. edwardsi, L. firmatoi, L. migonei, L. termitophila, L. tupynambai, L. fischeri, L. pessoai, L. lutziana, L. shannoni, L. barrettoi, L. intermedia, L. whitmani, L. lloydi, and L. minasensis. L. intermedia (38.3%) and L. whitmani (38.6%) predominated. L. intermedia predominated in the peridomicile, where it displayed more intense anthropophily, while L. whitmani displayed greater density in the banana plantations and forest, preferential sites for biting humans. Studies on seasonality showed that while L. intermedia displayed greater density in the hottest months of the year (December, January, and February), L. whitmani was abundant in the coolest months (June, July, and August), although both occurred throughout the year.

Dengue virus type 3 isolation from Aedes aegypti in the municipality of Nova Iguaçu, State of Rio de Janeiro

In a prospective field study conducted from July 2000 to June 2001, adult Aedes aegypti and Ae. albopictus mosquitoes were caught from the municipality of Nova Iguaçu, State of Rio de Janeiro, Brazil. Virus isolation in Ae. albopictus clone C6/36 cell line and a semi-nested reverse transcription-polymerase chain reaction detected only dengue virus type 3 in three pools of Ae. aegypti, despite the co-circulation of DEN-1, DEN-2 and DEN-3 serotypes in that area. No viruses were detected in Ae. albopictus mosquitoes. This virological surveillance consists in a sentinel system alerting for dengue outbreaks.

Clinical and epidemiological aspects of human parvovirus B19 infection in an urban area in Brazil (Niterói city area, State of Rio de Janeiro, Brazil)

This study was designed to analyse the clinical and epidemiological data from human parvovirus B19 cases in a six-year study of rash diseases conduct in an urban area in Brazil (Niterói city area, State of Rio de Janeiro). A total of 673 patients with acute rash diseases were seen at two primary health care units and at a general hospital. A clotted blood sample was collected from all subjects at the time of consultation. Forty-nine per cent (330 cases) of the patients were negative for dengue, rubella and measles IgM or for low avidity IgG to HHV-6. Of these 330, 105 (31.8%) were identified as IgM positive to parvovirus B19 by using an antibody capture EIA. During the study period, three distinct peaks of parvovirus infection were detected, suggesting that the disease appears to cycle in approximately 4-5 years. B19 infection was characterized by variable combinations of fever, flu-like symptoms, arthropathy, and gastrointestinal symptoms. Frequency of fever and arthropathy was substantially higher in adults, 75% [chi2 (1 D.F.) = 11.39, p = 0.0007] and 62.5% [chi2 (1 D.F.) = 29.89, p = 0.0000], respectively. "Slapped-cheek" appearance and reticular or lace-like rash were seen in only 30.1% of the children. No adult presented this typical rash. The lack of the typical rash pattern in a large proportion of parvovirus B19 and the similarity of clinical manifestations to other rash diseases, specially to rubella, highlight the difficulty of diagnosing B19 infection on clinical grounds alone.

Freshwater snails and Schistosomiasis mansoni in the state of Rio de Janeiro, Brazil: III - Baixadas Mesoregion

In this paper, the third of a series dealing with the survey of freshwater gastropods of the state of Rio de Janeiro, the results of collections carried out in the Mesoregion Baixadas from 2000 to 2002 are presented. Twenty-two species, belonging to seven families, were found. As to the snail intermediate hosts of Schistosoma mansoni, the most frequent species was Biomphalaria tenagophila besides some new findings of Biomphalaria straminea. No specimens were found harboring larval forms of S. mansoni although different kinds of cercariae had been observed.

The patterns of tungiasis in Araruama township, state of Rio de Janeiro, Brazil

This paper describes patterns of infestation with Tunga penetrans (L., 1758) within the poor community of Araruama municipality, State of Rio de Janeiro, Brazil, assessed by the number of persons and domestic animals parasitized. The overall prevalence of infestation was 49.2% (211 parasitized hosts) of the 429 examined. Humans (p < 0.01) and dogs (p < 0.01) were the most important hosts with 62.6% and 35.6% respectively. Dogs were considered as the potential infestation source to humans. Considering sex and age groups, both measures showed a significant difference (p < 0.01): female (62.2% infested of 143 examined) and male (43.9% infested of 98 examined). All age classes were found infested with significant difference (G = 42.5; p < 0.01) and most of the infestation occurred in children in the 0-9-year old category (27.3%). In contrast and based on mean of chigoe burden per person, the parasitic intensity was significantly higher on male than on female in all age categories, except for the 50+ (H = 27.1; p < 0.01) and decreasing with the increase of age (chi2 = 69.7, A = -124.6, p < 0.01). Growing urbanization, improved housing and sewage systems, use of appropriate footwear, examination of the feet principally in young children, antitetanus prophylaxis and reduction of stray dogs population are the major prophylactic methods recommended.

Dispersal of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in an urban endemic dengue area in the State of Rio de Janeiro, Brazil

Experimental releases of female Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus were performed in August and September 1999, in an urban area of Nova Iguaçu, State of Rio de Janeiro, Brazil, to estimate their flight range in a circular area of 1,600 m where 1,472 ovitraps were set. Releases of 3,055 Ae. aegypti and 2,225 Ae. albopictus females, fed with rubidium (Rb)-marked blood and surgically prevented from subsequent blood-feeding, were separated by 11 days. Rb was detected in ovitrap-collected eggs by atomic emission spectrophotometry. Rb-marked eggs of both species were detected up to 800 m from the release point. Eggs of Ae. albopictus were more numerous and more heterogeneously distributed in the area than those of Ae. aegypti. Eggs positively marked for Rb were found at all borders of the study area, suggesting that egg laying also occurred beyond these limits. Results from this study suggest that females can fly at least 800 m in 6 days and, if infected, potentially spread virus rapidly.

A new species of Acantholochus (Copepoda: Bomolochidae) parasitic on Centropomus undecimalis (Osteichthyes: Centropomidae) from the coastal zone of the State of Rio de Janeiro, Brazil

A new species of Acantholochus Cressey, 1984 (Copepoda: Bomolochidae) parasitic on the gills of common snook, Centropomus undecimalis, from the coastal zone of the State of Rio de Janeiro, Brazil, is described and illustrated. The new species differs from all other species of Acantholochus by the presence of only one inner seta on middle segment of the second and third endopods.

Comparative immunological recognition of proteins from New Guinea "C" dengue virus type 2 prototype and from a dengue virus type 2 strain isolated in the State of Rio de Janeiro, Brazil

The protein profiles of the New Guinea "C" dengue virus type 2 (DENV-2)prototype and those of a Brazilian DENV-2 isolated in the State of Rio de Janeiro in 1995 were compared. SDS-PAGE analysis showed that the virus from Rio de Janeiro expresses NS5 (93.0 kDa), NS3 (66.8 kDa) E (62.4 kDa) and NS1 (41.2 kDa) proteins differently from the New Guinea "C" virus. The immunoblot revealed specificity and antigenicity for the NS3 protein from DENV-2 Rio de Janeiro mainly in primary infections, convalescent cases, and in secondary infections in both cases and only antigenicity for E and NS1 proteins for both viruses in primary and secondary infections.

Evaluation of the impact of Bacillus thuringiensis serovar israelensis and Temephos, used for the control of Simulium (Chirostilbia) pertinax Kollar, 1832 (Diptera, Simuliidae) on the associated entomofauna, Paraty, state of Rio de Janeiro, Brazil

The study was set up to evaluate the impact of two commercial larvicide formulations, Bacillus thuringiensis serovar israelensis base (Bti) at 15 ppm/1 min and temephos at 0.03 ppm of active ingredient, used to control Simulium pertinax populations, on associated non-target entomofauna occupying the same breeding sites. The experiments were carried out on the Pedra Branca and Muricana rivers, on the slopes of Serra do Mar massif, municipality of Paraty, state of Rio de Janeiro, Brazil. Bti was applied to the river Pedra Branca and temephosto theriver Muricana. On both rivers, treatment and control sections were labeled as such, each one with two observation posts: slow moving water and fast water regions respectively. Artificial substrata was used to evaluate the abundance of associated entomofauna. Attached immature stages of arthropods were removed from both of its surfaces fortnightly. Were collected, from the two rivers, 28 477 specimens of the entomofauna associated with S. pertinax. The families Hydropsychidae, Chironomidae, Bactidae, Simuliidae, Blephariceridae and Megapodagrionidae were represented. These was an impact of temephos on the entomofauna associated with S. pertinax only in Simuliidae and Chironomidae, and to Bti only in Simuliidae. However, the reduction in their numbers was not statistically significant.

Host-ectoparasite specificity in a small mammal community in an area of Atlantic Rain Forest (Ilha Grande, State of Rio de Janeiro), Southeastern Brazil

The analyses of the ectoparasite species associated with a small mammal community on Ilha Grande, a coastal island in southern of the state of Rio de Janeiro, Brazil, evaluated the level of host-ectoparasite specificity. Was used the Jaccard index for qualitative data to analyse the similarity. The lowest value of similarity occurred between Proechimys iheringi and Marmosops incanus and between Sciurus aestuans and Nectomys squamipes (Cj = 0.08) and the highest between P. iheringi and Oxymycterus sp. (Cj = 0.33). This index showed a low value of similarity across the ectoparasite community. The only exception from this pattern of high host specificity occurred with P. iheringi and Oxymycterus sp., which shared five species of ectoparasites. The similarity values, for most of the cases, is smaller than 0.2.

Aedes aegypti resistance to temephos during 2001 in several municipalities in the states of Rio de Janeiro, Sergipe, and Alagoas, Brazil

For more than 30 years temephos, an organophosphate insecticide, has been the sole larvicide used in Brazil in the control of Aedes aegypti. Organophosphates were also used for adult control, being replaced by pyrethroids since l999. In this same year, the Brazilian Health Foundation started the coordination of the Ae. aegypti Insecticide Resistance Monitoring Program. In the context of this program, our group was responsible for the detection of temephos resistance in a total of 12 municipalities in the states of Rio de Janeiro (RJ), Alagoas (AL), and Sergipe (SE) during 2001. In each municipality, a pool of mosquitoes collected from different districts was used, with the exception of Rio de Janeiro city, where eight districts have been separately evaluated. Exposure of larvae to the diagnostic dose of temephos revealed resistance in all localities examined, with mortality levels ranging from 4% (Pilares district, Rio de Janeiro, RJ) to 61.9% (Campos dos Goytacazes, RJ). Quantification of mortality showed resistance ratios from 6.1 (Aracaju, SE) to 16.8 (São Gonçalo, RJ and Penha district, Rio de Janeiro, RJ). The national dengue control program is presently using these data to subside insecticide resistance management.

Freshwater snails and Schistosomiasis mansoni in the state of Rio de Janeiro, Brazil: IV - Sul Fluminense Mesoregion

In this paper, the forth of a series dealing with the survey of freshwater gastropods of the state of Rio de Janeiro, the results of collections carried out in the Sul Fluminense Mesoregion from 2000 to 2002 are presented and revealed the occurrence of 18 species: Antillorbis nordestensis; Biomphalaria glabrata; Biomphalaria peregrina; Biomphalaria straminea; Biomphalaria tenagophila; Drepanotrema anatinum; Drepanotrema cimex; Drepanotrema lucidum; Ferrissia sp.; Gundlachia ticaga; Gundlachia sp.; Heleobia sp.; Lymnaea columella; Melanoides tuberculatus; Physa acuta; Physa marmorata; Pomacea sordida and Pomacea sp. As to the snail hosts of Schistosoma mansoni the most frequent species was B. tenagophila, found in all municipalities surveyed, except Parati. Besides new records the present study extends the distribution of B. peregrina and B. straminea in the state. No specimens were found harbouring larval forms of S. mansoni although different kinds of cercariae had been observed. An account about the current schistosomiasis transmission sites in this Mesoregion is presented as well.

Freshwater snails and schistosomiasis mansoni in the state of Rio de Janeiro, Brazil: V - Norte fluminense mesoregion

In this paper, the fifth of a series dealing with the survey of freshwater gastropods of the state of Rio de Janeiro, the results of collections carried out in the Norte Fluminense Mesoregion from 2002 to 2003 are presented and revealed the occurrence of 19 species: Antillorbis nordestensis; Burnupia sp.; Biomphalaria tenagophila; Drepanotrema anatinum; Drepanotrema cimex; Drepanotrema depressissimum; Drepanotrema lucidum; Ferrissia sp.; Gundlachia ticaga; Gundlachia sp.; Heleobia sp.; Hebetancylus moricandi; Idiopyrgus sp.; Lymnaea columella; Melanoides tuberculatus; Physa acuta; Physa marmorata; Pomacea sordida, and Pomacea sp. Concerning the snail hosts of Schistosoma mansoni only B. tenagophila was found, in contrast with other previuosly studied mesoregions.No specimens were found harbouring larval forms of S. mansoni although different kinds of cercariae had been observed.An account about the current schistosomiasis transmission sites in this Mesoregion is presented as well.

Parvovirus B19 infections in state of Rio de Janeiro, Brasil: 526 sera analyzed by IgM-enzyme-linked immunosorbent assay and polymerase chain reaction

In this study were analyzed 526 sera; the patients aged from two days to 65 years old presenting exanthema, which was the most frequent symptom observed, besides fever, adenomegaly, and arthralgia. These sera were negative by enzyme-linked immunosorbent assay (IgM-ELISA) for either rubella (495), toxoplasma (41), cytomegalovirus (12), measles (40), dengue (56), and they were submitted to nested polymerase chain reaction (PCR) for B19 DNA and commercial IgM-ELISA for B19. In 39 abortion cases, IgM or DNA were not detected, therefore they were not took into account for analysis. Specific DNA and IgM were detected respectively in 71 (14.5%) and IgM in 62 (12.7%) sera from 487 sera analyzed. IgM and DNA were simultaneously detected in 43 (8.8%), while agreement among the results by PCR and IgM-ELISA was observed in 440 (90.4%). The sera were collected from January 1999 to December 2000, most of them in 1999 (325), during winter and spring. The major number of clinical cases was observed in the age group from one to ten years old. IgM or DNA were detected in 23 from 51 municipal districts of the state of Rio de Janeiro, where the samples were collected.

Freshwater snails and schistosomiasis mansoni in the state of Rio de Janeiro, Brazil: VI - Noroeste Fluminense Mesoregion

In this paper, the last of a series dealing with the survey of freshwater gastropods of the state of Rio de Janeiro, the results of collections carried out in the Noroeste Fluminense Mesoregion from 2002 to 2005 are presented and revealed the occurrence of 20 species: Antillorbis nordestensis; Biomphalaria glabrata; B. straminea; B. tenagophila; Drepanotrema anatinum; D. cimex; D. depressissimum; D. lucidum; Ferrissia sp.; Gundlachia ticaga; Gundlachia sp.; Heleobia sp.; Idiopyrgus sp.; Lymnaea columella; Melanoides tuberculatus; Physa acuta; P. marmorata; Plesiophysa guadeloupensis; Pomacea lineata; and Pomacea sp. Concerning the snail hosts of schistosomiasis the three natural vectors were identified and, although no specimens were found harbouring larval forms of Schistosoma mansoni, different kinds of cercariae had been observed.