Eosinophilic meningitis (EoM) is an acute disease that affects the central nervous system. It is primarily caused by infection with the nematode Angiostrongylus cantonensis. This infection was ...previously restricted to certain Asian countries and the Pacific Islands, but it was first reported in Brazil in 2007. Since then, intermediate and definitive hosts infected with A. cantonensis have been identified within the urban areas of many states in Brazil, including those in the northern, northeastern, southeastern and southern regions. The goals of this review are to draw the attention of the medical community and health centres to the emergence of EoM in Brazil, to compile information about several aspects of the human infection and mode of transmission and to provide a short protocol of procedures for the diagnosis of this disease.
Near Infrared Spectroscopy (NIRS) has been applied in epidemiological surveillance studies of insect vectors of parasitic diseases, such as the Dengue's mosquitoes. However, regarding mollusks, ...vectors of important worldwide helminth diseases such as schistosomiasis, fascioliasis and angiostrongyliasis, NIRS studies are rare. This work proposes to establish and standardize the procedure of data collection and analysis using NIRS applied to medical malacology, i.e., to mollusk vectors identifications. Biomphalaria shells and live snails were analyzed regarding several operational aspects, such as: moisture, shell side and position of the live animal for acquisition of NIR spectra. Representative spectra of Biomphalaria shells and live snails were collected using an average of 50 scans per sample and resolution of 16 cm-1. For shells, the sample should first be dried for a minimum of 15 days at an average temperature of 26±1°C, and then placed directly in the equipment measurement window with its left side facing the light beam. Live animals should be dried with absorbent paper; placed into a glass jar, and analyzed similarly to the shells. Once standardized, the technique was applied aiming at two objectives: identification of Biomphalaria using only the shells and parasitological diagnosis for Schistosoma mansoni infection. The discrimination of the three Biomphalaria species intermediate hosts of S. mansoni only by shell has technical limit due to the scarcity of organic material. Nevertheless, it was possible to differentiate B. straminea from B. tenagophila and B. glabrata with 96% accuracy. As for the parasitological diagnosis, it was possible to differentiate infected mollusks shedding S. mansoni cercariae from the non-infected ones with 82, 5% accuracy. In conclusion, the Near Infrared Spectroscopy (NIR's) technique has proven to be an innovative and sound tool to detect infection by S. mansoni in the different species of Biomphalaria intermediate hosts.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Metastrongyloidea includes nematodes that parasitize mammals, mainly infecting their respiratory and cardiovascular systems, and are responsible for emerging zoonosis in the world. Terrestrial ...mollusks are their main intermediate hosts, with few exceptions. Here we present the results of a malacological survey to know the distribution of
in Macapá, Amapá, in the Brazilian Amazon region, after the report of a case of eosinophilic meningitis in 2018. Mollusks were collected in 45 neighborhoods between March 2019 and February 2020. They were identified, parasitologically analyzed, and their nematodes parasites were identified based on the morphology and MT-CO1 sequencing. Infections of An. cantonensis were observed in
,
and
. These are the first records of the natural infection of the last two species by
in the Brazilian Amazon region. The angiostrongylid
, which parasitizes cats, was also detected parasitizing
and
. This is also the first record of the slug
infected by
. The highest infection rates were recorded in neighborhoods where the environment conditions favor the proliferation of both mollusks and rodents. The results demonstrate the ample distribution of
in Macapá and the need for surveillance and mollusk vector control in Brazil and other countries.
is a nematode parasite that resides in the pulmonary arteries of rodents, serving as its definitive hosts. The life cycle involves several species of non-marine gastropods as intermediate hosts, and ...the African giant snail
is considered one of the most important around the world. Experimental data concerning
.
infection in the African giant snail remains notably limited. This helminth causes eosinophilic meningitis or meningoencephalitis in humans, representing an emergent zoonosis in Brazil. Understanding the host-parasite relationship through the application of new tools is crucial, given the complex interaction between zoonosis and the intricate mechanisms involving wild/human hosts, parasite adaptation, and dispersion. The objective of this study was to employ SEM as a novel methodology to understand the structural organization of the host tissue, particularly the granuloma formation. This sheds light on the complex balance between
and
. Nine three-month-old snails were randomly selected and exposed for 24 h to a concentration of 2000 L1/dose of
. A necropsy was performed 37 days after the infection, and the samples were examined using light and scanning electron microscopy (SEM). The histopathological results revealed third-stage larvae of
.
associated with granulomas distributed throughout the head-foot mass, mantle, and kidney. Scanning electron microscopy of the histological section surface showed that the granuloma is surrounded by a cluster of spherical particles, which are distributed in the region bordering the larvae. This reveal details of the nematode structure, demonstrating how this methodology can enhance our understanding of the role of granulomas in molluscan tissue. The structural characteristics of granuloma formation in
.
suggest it as an excellent invertebrate host for
.
. This relationship appears to provide protection to the parasite against the host's immune defense system while isolating the snail's tissue from potential exposure to nematode antigens.
The artificially created Lake Pampulha, within the metropolitan area of Belo Horizonte, Minas Gerais State, lacks detailed information about its freshwater mollusks, representing a challenge for the ...assessment and conservation of this ecosystem. In this study, conducted during June and August 2021, we collected specimens on four different occasions and at five sampling points around the lake, using different sampling equipment, such as a shovel and a scoop. During these collections, we identified, enumerated and measured 1538 species of mollusks and additionally examined the presence of trematode larvae. We identified twelve species of fresh water bivalves and gastropods: Biomphalaria straminea, Biomphalaria kuhniana, Biomphalaria occidentalis, Drepanotrema cimex, Pomacea maculata, Stenophysa marmorata, Physa acuta, Gundlachia ticaga, Melanoides tuberculata, Pseudosuccinea columella, Omalonyx matheroni and Corbicula largillierti. Echinostome and strigeocercaria types of larval trematodes were detected in B. straminea. Notably, some species of mollusks have not previously been recorded at Lake Pampulha. The analyses revealed differences in the composition and abundance of species, highlighting the higher number of mollusk species in areas more impacted by human actions. This study expands our understanding of mollusk diversity at Lake Pampulha, and provides valuable data for longitudinal comparisons of water quality and considerations of the conservation of native species. Furthermore, it highlights the importance of choosing appropriate sampling equipment, depending on the research objectives. The presence of invasive species of medical and veterinary relevance as intermediate hosts of parasites reinforces the need for efficient environmental protection strategies to preserve this artificial, aquatic environment widely used by the local population and by tourists.
In January and February 2019, a malacological survey was conducted in the area surrounding the residence of a 12-year-old child that had contracted cerebral angiostrongyliasis in the municipality of ...Macapá, capital of the Amapá State, northern Brazil. The serological examination was positive for
Angiostrongylus cantonensis
infection, the principal etiological agent of this parasitosis. A sample of 54 molluscs was artificially and individually digested for parasitological analysis, containing 38 specimens of
Achatina fulica
, nine specimens of
Bulimulus tenuissimus
and seven specimens of
Sarasinula linguaeformis
.
A. fulica
was the most abundant mollusc, and the only species infected with
A. cantonensis
, as well as presenting co-infections with other nematodes. This is the first report of cerebral angiostrongyliasis in the Amazon Region, and the first record of
A. fulica
infected with
A. cantonensis
in Amapá. These findings highlight the potential risks of human angiostrongyliasis, and the need to implement public health measures to control the spread of the disease.
The movement of species is among the most serious environmental threats of the new millennium, as the transplantation of species beyond their native or historical range has intensified in the last ...five decades. Traditionally, studies on bioinvasions have focused on species that have been introduced, deliberately or accidentally, to biogeographic regions where they did not previously occur. However, less attention has been given to species movement to novel areas within the same biogeographic region. Our research group, the South America Introduced Molluscs Specialists, analyzed potential cases of native South American mollusc species introduced deliberately or accidentally beyond their natural range within South America. To achieve this, it is key to differentiate between anthropogenic processes and passive responses to environmental conditions. We considered the past and current spatial distribution of species, analyzed known or putative vectors, and discuss the impacts of taxonomic and nomenclatural knowledge. Based on the evidence currently available, we propose different scenarios to explain observed changes in mollusc distributions within South America. Seventeen transplanted mollusc species (TMS) were recognized, considering marine, freshwater, and terrestrial environments. Of the 189 South American ecoregions 31 were occupied by transplanted species, but this proportion varied by environment: 10 of 28 marine ecoregions, 12 of 52 freshwater ecoregions, and 9 of 109 terrestrial ecoregions. The ecoregions with TMS are generally located in the peripheral zones of the continent. Those with the highest number of TMS were the Southern Caribbean (three species) in the marine environment, the Central Andean Pacific Slopes (three species) in the freshwater environment, and the Alto Paraná Atlantic forests (two species) in the terrestrial environment. The number of unintentionally moved TMS is greater than those moved intentionally. The transplantation process is similar to the introduction and settlement process of non-native mollusc species, and so is their impact.
Biomphalaria glabrata is considered to be responsible for the incidence of schistosomiasis in Brazil. Therefore, surveillance of areas where schistosomiasis is prevalent is fundamental for public ...health planning. This study was aimed to evaluate B. glabrata populations in water bodies of the city of Salvador, determine their distribution, estimate the prevalence of Schistosoma mansoni infections, characterize shed cercariae, and identify transmission foci.
Malacological surveys were carried out in 17 water collections from Salvador. Snail species were identified based on shell and mantle characteristics. Snails were evaluated for S. mansoni infection by exposure to light and via real time polymerase chain reaction (qPCR) using S. mansoni-18S rRNA subunit specific primers.
1,403 B. glabrata were collected. Classical cercarial shedding indicated that 5 snails (0.4%) were positive for S. mansoni. A higher prevalence of infections was found in Horta de Saramandaia (5.5%) and Lagoa do IAT (1.9%). Non-Schistosoma larvae, such as Xiphidiocercaria, Strigeidae, Spirorchiidae and Clinostomidae, were observed in 3.2% of the snails. S. mansoni DNA was detected in 6.2% snails via qPCR.
B. glabrata is widely distributed in Salvador, as indicated by 7 water collections associated with a risk of schistosomiasis transmission. To our knowledge, this is the first study to identify B. glabrata eliminating cercariae of Clinostomidae, Strigeidae, and Spirorchiidae in Salvador. We propose that qPCR may be employed in combination with classical cercarial shedding. Estimating S. mansoni prevalence in snails by only considering the results of light exposure method classical into account may underestimate the problem.
Human neural angiostrongyliasis is an emerging infectious disease caused by nematode Angiostrongylus cantonensis. The present study investigated the presence of Angiostrongylus spp. in terrestrial ...molluscs collected from the following areas in the Metropolitan Region of Aracaju, Sergipe State, Brazil: Barra dos Coqueiros, Nossa Senhora do Socorro, Sao Cristovao and Aracaju. In total, 703 specimens representing 13 mollusc species were screened for Angiostrongylus spp. Larvae of Angiostrongylus spp. were found in three species. Larvae recovered from Achatina fulica were used for experimental infection in Wistar rats (Rattus norvegicus). For specific identification of nematodes, the mitochondrial cytochrome c oxidase subunit I (COI) was sequenced from both larvae and adults recovered from molluscs and rats, respectively. Infection with A. cantonensis was detected in all municipalities and in the following three host species: Bulimulus tenuissimus, Cyclodontina fasciata (Barra dos Coqueiros), and A. fulica (Aracaju, Nossa Senhora do Socorro and Sao Cristovao). Co-infections were also found with Caenorhabditis sp. and Strongyluris sp. larvae. This is the first study of the helminth fauna associated with the terrestrial malacofauna in Sergipe State, and confirms that these three snail species are involved in the transmission of A. cantonensis in the state. In addition, B. tenuissimus and C. fasciata are newly reported natural hosts of the parasite.
Planorbidae comprises approximately 40 genera of freshwater gastropods, including roughly 250 species. Among the Planorbidae subfamilies, the significance of Planorbinae is due to its genus
, whose ...species are intermediate hosts of the trematode
Sambon, 1907, which causes schistosomiasis in humans and animals. Here, we present the analysis of the dataset of Planorbidae housed in the Collection of Mollusks of the Oswaldo Cruz Institute, with a special focus on
species. This dataset includes 7,267 lots originating from 55 countries, representing 20 genera and 75 species collected from 1948 to 2023. Collections were performed in all regions of Brazil, comprising specimens from 26 states and the Federal District, particularly from the Southeast and Northeast. Within the dataset,
includes 3,926 lots of 31 species from 42 countries. These records will help improve our comprehension of schistosomiasis transmission dynamics and the geographic distributions of these medically important species.
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