Melanoides tuberculatus (Gastropoda: Thiaridae) as intermediate host of Heterophyidae (Trematoda: Digenea) in Rio de Janeiro metropolitan area, Brazil

In the late 1960s, Melanoides tuberculatus snails were introduced in Brazil from North/East Africa and Southeast Asia. The first records of specimens infected with cercariae were registered in Rio de Janeiro State in 2001. The present study reports the occurrence of M. tuberculatus infected with larval trematodes in Rio de Janeiro City. Bottom sediment was collected with dip nets and sieved through 0.25 inch-mesh screening. Snails were transported to the laboratory in vials with stream water, then measured and individually isolated in glass vials with distilled water. They were exposed to artificial light and temperature to induce cercarial emergence. The most actively emerging cercariae were processed by differential staining and silver nitrate impregnation methods. Negative snails were subsequently dissected. Approximately 700 snails were collected. Snail total lengths ranged from 1.2 to 3.3 cm. The prevalence rate was 15.76% although 53.76% of the snails were found infected in one of the sites. Infected snails were infected with rediae and pleurolophocercous cercariae. Cercarial morphology and chaetotaxy were consistent with those of the family Heterophyidae mostly due to the presence of median dorsal and ventral fins on the tail and the absence of CI dorsal sensory receptors.

Seroepidemiology of toxoplasmosis in women of childbearing age from a marginal community of Maracaibo, Venezuela

The aim of this study was to determine the prevalence of anti-T. gondii total and IgM antibodies in women of childbearing age. One hundred serum samples of women were studied with age range from 11 to 45 years old. Samples were chosen by random. The determination of total antibodies was carried out through the indirect hemagglutination technique and IgM antibodies by ELISA's technique. The statistical analysis was carried out through the Chi square and the Spearman correlation tests. The theoretical estimated incidence of congenital toxoplasmosis was calculated, according to the annual increment of antibody prevalence among the age groups. The overall prevalence of toxoplasmosis was 33%, while only six individuals (18.2%) were positive to IgM. The highest prevalence was observed in the 11-35 year-old age group. The theoretical estimated incidence was 1.5 for 100 pregnancies in women of 21-25 year-old group; it decreased until 0.1% in the 41-45 year-old age group. The findings show a high prevalence of toxoplasmosis in this community with a high infection risk in women of the studied age group and the high cat population observed, suggesting that the transmission way by contaminated soils may play a main role in the spreading of toxoplasmosis in this community.

Indications of carbapenem resistance evolution through heteroresistance as an intermediate stage in Acinetobacter baumannii after carbapenem administration

We describe an in vivo evolution of an antimicrobial profile from susceptibility to full-resistance to carbapenems, with heteroresistance as an intermediate stage, in an Acinetobacter baumannii strain. Heteroresistance was characterized by the growth of sub-populations within the susceptibility halo in both disk-diffusion and Etest. PCRs for the main A. baumannii carbapenemases were negative. The exact resistance mechanism, diagnostic methods and clinical relevance of heteroresistance in A. baumannii warrant further investigations. This is the first description of such phenomenon in vivo and the second report of heteroresistance to carbapenems in A. baumannii.

Melanoides tuberculata (Mollusca: Thiaridae) as an intermediate host of Centrocestus formosanus (Trematoda: Heterophyidae) in Brazil

Pleurolophocercous cercariae emerged from naturally infected Melanoides tuberculata from Minas Gerais State, Brazil, were used to perform experimental infection of laboratory-reared Poecilia reticulata. Mature metacercariae were obtained from the gills of fishes and force-fed to Mus musculus. The adult parasites which recovered from small intestines of mice were identified as Centrocestus formosanus. This is the first report of M. tuberculata as intermediate host of this heterophyid in Brazil.

Melanoides tuberculata as intermediate host of Philophthalmus gralli in Brazil

Melanoides tuberculata that naturally harbored trematode larvae were collected at the Pampulha dam, Belo Horizonte (Minas Gerais, Brazil), during malacological surveys conducted from 2006 to 2010. From 7,164 specimens of M. tuberculata collected, 25 (0.35%) were infected by cercariae, which have been morphologically characterized as belonging to the Megalurous group, genus Philophthalmus. Excysted metacercariae were used for successful experimental infection of Gallus gallus domesticus, and adult parasites recovered from the nictitating membranes of chickens were identified as Philophthalmus gralli. This is the first report of P. gralli in M. tuberculata in Brazil.

SPATIAL DISTRIBUTION OF LYMNAEIDAE (MOLLUSCA, BASOMMATOPHORA), INTERMEDIATE HOST OF Fasciola hepatica LINNAEUS, 1758 (TREMATODA, DIGENEA) IN BRAZIL

Snails of the family Lymnaeidae act as intermediate hosts in the biological cycle of Fasciola hepatica, which is a biological agent of fasciolosis, a parasitic disease of medical importance for humans and animals. The present work aimed to update and map the spatial distribution of the intermediate host snails of F. hepatica in Brazil. Data on the distribution of lymnaeids species were compiled from the Collection of Medical Malacology (Fiocruz-CMM, CPqRR), Collection of Malacology (MZUSP), “SpeciesLink” (CRIA) network and through systematic surveys in the literature. Our maps of the distribution of lymnaeids show that Pseudosuccinea columella is the most common species and it is widespread in the South and Southeast with few records in the Midwest, North and Northeast regions. The distribution of the Galba viatrix, G. cubensis and G. truncatula showed a few records in the South and Southeast regions, they were not reported for the Midwest, North and Northeast. In addition, in the South region there are a few records for G. viatrix and one occurrence of Lymnaea rupestris. Our findings resulted in the first map of the spatial distribution of Lymnaeidae species in Brazil which might be useful to better understand the fasciolosis distribution and delineate priority areas for control interventions.

MONTENEGRO SKIN TEST AND AGE OF SKIN LESION AS PREDICTORS OF TREATMENT FAILURE IN CUTANEOUS LEISHMANIASIS

A case-control study was conducted to examine the association among the Montenegro skin test (MST), age of skin lesion and therapeutic response in patients with cutaneous leishmaniasis (CL) treated at Evandro Chagas National Institute of Infectious Diseases (INI), Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil. For each treatment failure (case), two controls showing skin lesion healing following treatment, paired by sex and age, were randomly selected. All patients were treated with 5 mg Sb5+/kg/day of intramuscular meglumine antimoniate (Sb5+) for 30 successive days. Patients with CL were approximately five times more likely to fail when lesions were less than two months old at the first appointment. Patients with treatment failure showed less intense MST reactions than patients progressing to clinical cure. For each 10 mm of increase in MST response, there was a 26% reduction in the chance of treatment failure. An early treatment - defined as a treatment applied for skin lesions, which starts when they are less than two months old at the first appointment -, as well as a poor cellular immune response, reflected by lower reactivity in MST, were associated with treatment failure in cutaneous leishmaniasis.

Anopheles (Kerteszia) cruzii (DIPTERA: CULICIDAE) IN PERIDOMICILIARY AREA DURING ASYMPTOMATIC MALARIA TRANSMISSION IN THE ATLANTIC FOREST: MOLECULAR IDENTIFICATION OF BLOOD-MEAL SOURCES INDICATES HUMANS AS PRIMARY INTERMEDIATE HOSTS

Anopheles (Kerteszia) cruzii has been implicated as the primary vector of human and simian malarias out of the Brazilian Amazon and specifically in the Atlantic Forest regions. The presence of asymptomatic human cases, parasite-positive wild monkeys and the similarity between the parasites infecting them support the discussion whether these infections can be considered as a zoonosis. Although many aspects of the biology of An. cruzii have already been addressed, studies conducted during outbreaks of malaria transmission, aiming at the analysis of blood feeding and infectivity, are missing in the Atlantic Forest. This study was conducted in the location of Palestina, Juquitiba, where annually the majority of autochthonous human cases are notified in the Atlantic Forest of the state of São Paulo. Peridomiciliary sites were selected for collection of mosquitoes in a perimeter of up to 100 m around the residences of human malaria cases. The mosquitoes were analyzed with the purpose of molecular identification of blood-meal sources and to examine the prevalence of Plasmodium. A total of 13,441 females of An. (Ker.) cruzii were collected. The minimum infection rate was calculated at 0.03% and 0.01%, respectively, for P. vivax and P. malariae and only human blood was detected in the blood-fed mosquitoes analyzed. This data reinforce the hypothesis that asymptomatic human carriers are the main source of anopheline infection in the peridomiciliary area, making the probability of zoonotic transmission less likely to happen.

MOLLUSCICIDAL AND LARVICIDAL ACTIVITIES OF Atriplex inflata AERIAL PARTS AGAINST THE MOLLUSK Galba truncatula, INTERMEDIATE HOST OF Fasciola hepatica

Fasciolosis is a widespread parasitosis of farm live-stock in many developing countries. For this reason, it is necessary to search for new substances against parasitic diseases caused by flukes. Indeed, a wide variety of terrestrial plants have been subjected to chemical and pharmacological screening in order to discover their potential for human medicinal use. The molluscicidal and larvicidal activities of Atriplex inflata were tested on Galba truncatula and Fasciola hepatica larval stages infecting this snail in Tunisia. Phytochemical tests were conducted on extracts in order to establish a meaningful relationship with molluscicidal and larvicidal activities. The molluscicidal activity was evaluated by subjecting snails to sample aqueous solutions. Accordingly, hexane, ethyl acetate, methanol and methanol-water (8:2, v-v) were used as extraction solvents. As a result, hexane and ethyl acetate extracts showed potent activity, according to the World Health Organization, giving LC50 = 7.59 mg/L and 6.69 mg/L for hexane extracts of leaves and fruits, respectively. Ethyl acetate extracts gave LC50 = 5.90 mg/L and 7.32 mg/L for leaves and fruits, successively. Molluscicidal activities of powders were less potent on snails, but active according to the World Health Organization. Hexane and ethyl acetate extracts from leaves and fruits gave potent larvicidal activities with a delay rate exceeding 45.50% (45.50- 98.92%). Phytochemical tests showed that these activities may be attributed to the presence of triterpenoids and/or sterols.

Pattern of acquisition of rotavirus antibody in children followed up from birth to the age of three years

Nine hundred and forty-eight serum samples from 83 children living in Belem, Brazil, collected'within their first three years of life, were testedfor the presence of group- specific rotavirus-antibody by an enzyme-linked immunosorbent assay (ELISA) blocking-test. Passively transferred maternal antibody lasted about two and half months; subsequentely, low levels of rotavirus antibody started to appear at seven months, reaching a peak at eleven months of age. From one year onwards positivity gradually increased, reaching highest values at 34 months of life. Individual responses were examined in sera from 61 children who were followed up since birth to three years of age: 38 (62,3%) ofthem developed a long-term immunity following first infection; eleven (18.0%) children developed a short-term immunity after first infection by rotavirus; seven (11.5%) had no antibody response within their first three years of life; and 5 (8.2%) showed positive antibody response from birth to three years old.

Angiostrongylus costaricensis and the intermediate hosts: observations on elimination of L3 in the mucus and inoculation of L1 through the tegument of mollucs

Human accidental infection with Angiostrongylus costaricensis may result in abdominal disease of varied severity. Slugs from the Veronicellidae family are the main intermediate hosts for this parasitic nematode of rodents. Phyllocaulis variegatus, Phyllocaulis soleiformis and Phyllocaulis boraceiensis were experimentally infected to describe the kinetics of L3 elimination in the mucus secretions of those veronicelid species. A maximum of 2 L3/g/day was found in the mucus, while the number of L3 isolated from the fibromuscular tissues varied from 14 to 448. Productive infection was established by inoculations in the hyponotum or in the body cavity, through the tegument. Intra-cavity injection is a less complex procedure and permits a better control of inocula. A preliminary trial to titrate the infective dosis for P. variegatus indicated that inocula should range between 1000 and 5000 L1. The data also confirmed the importance of P. variegatus as an intermediate host of A. costaricensis.

Frequency of myocarditis in cases of fatal meningococcal infection in children: observations on 31 cases studied at autopsy

The frequency of myocarditis associated with meningococcal disease in children was reported only in two autopsied series (United States and South Africa). Here we report the frequency of associated myocarditis in 31 children who died of meningoccal infection at Hospital Infantil N.S. da Glória in Vitória, Espirito Santo State, Brazil. The diagnosis was confirmed by isolation of Neisseria meningitidis . At least three sections of fragments of both atria and ventricles were studied using the Dallas Criteria for the morphologic diagnosis of myocarditis. The mean age was 47.6 ± 39.8 months and the mean survival time after the onset of symptoms was 46.1 ± 26.5h (12-112h). Myocarditis was present in 13 (41.9%) patients, being of minimal severity in 11 cases and of moderate severity in 2 cases. There were no cases with severe diffuse myocarditis. The frequency of myocarditis was not influenced by sex, presence of meningitis, survival time after the onset of symptoms or use of vasoactive drugs. The frequency of myocarditis reported here was intermediate between the values reported in the only two case series published in the literature (57% in the United States and 27% in South Africa). Although our data confirm the high frequency of myocaditis in meningoccal disease, further investigations are necessary to elucidate the contribution of myocarditis to myocardial dysfunction observed in cases of meningococcal infection in children.

Report on the ocurrence of Angiostrongylus costaricensis in southern Brazil, in a new intermediate host from the genus Sarasinula (Veronicellidae, Gastropoda)

Veronicellid slugs are the main intermediate hosts for Angiostrongylus costaricencis. In a rural locality in Nova Itaberaba (SC, southern Brazil) Sarasinula linguaeformis was identified as a crop pest. The parasitological examination revealed A. costaricencis infection in 43 out ot 50 slugs. The prevalence of 86% and the individual parasitic burdens are the highest sofar reported in Brazil and S. linguaeformis is the first species from the genus Sarasinula to be identified as intermediate host for A. costaricencis in southern Brazil.