High prevalence and intensity of fish nematodes with zoonotic potential in the Brazilian Amazon, including a brief reflection on the absence of human infections

This study aimed to characterize the prevalence, mean abundance, and mean intensity of potential fish-borne zoonotic nematode larvae infecting the predator fish Hoplias aff. malabaricus from the Tapajós River, in the municipality of Santarém, in the Brazilian Amazon. After capture, the specimens of H. aff. malabaricus were analyzed for infection by Contracaecum sp. and Eustrongylides sp. third-stage larvae, and the prevalence, mean abundance, and mean intensity were calculated. A literature search was carried out to clarify the relationship between these indicators and eventual human cases of infection in the Amazon region. Third-stage larvae of nematodes of the Contracaecum and Eustrongylides genera were found in the specimens of H. aff. malabaricus sampled from the Tapajós River. The prevalence of Contracaecum larvae was 100%, while its mean abundance and mean intensity were both 54.8 larvae/fish. The prevalence of Eustrongylides larvae was 62.9%, and its mean abundance and mean intensity were 1.8 and 2.8 larvae/fish, respectively. Despite the high prevalence and intensity values, there are no cases of human infection by these nematode larvae in the Brazilian Amazon reported. The absence of human infections by these nematode larvae in the Brazilian Amazon despite the high prevalence/intensity of Contracaecum and Eustrongylides larvae and the high consumption of fish in the region, is most probably due to the fact that the local populations do not eat raw or undercooked fish. However, it is noteworthy that the absence of zoonotic cases in the region is based only on the examination of the available published papers. A better knowledge of the situation would require surveying hospitals and clinics, and data from the region’s medical treatment facilities. However, the authors consider that cases of human infection, if any, are extremely rare, mainly due to the eating habits of the local population. KEY WORDS: Amazon basin; freshwater fish; public health; parasitic infection; zoonosis.

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Lack of evidence for human infection with Xenotropic murine leukemia virus-related virus in the Brazilian Amazon basin

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/0037-8682-0075-2014 ◽

2014 ◽

Vol 47 (3) ◽

pp. 302-306 ◽

Cited By ~ 1

Author(s):

Samara Tatielle Monteiro Gomes ◽

Luciana Imbiriba ◽

Rommel Rodriguéz Burbano ◽

Artur Luiz da Costa Silva ◽

Rosimar Neris Martins Feitosa ◽

...

Keyword(s):

Murine Leukemia Virus ◽

Amazon Basin ◽

Leukemia Virus ◽

Brazilian Amazon ◽

Human Infection ◽

Xenotropic Murine Leukemia ◽

Related Virus ◽

Murine Leukemia

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Subcutaneous dirofilariasis caused by Dirofilaria (Nochtiella) repens in Sri Lanka: A potential risk of transmitting human dirofilariasis

SAGE Open Medical Case Reports ◽

10.1177/2050313x17701373 ◽

2017 ◽

Vol 5 ◽

pp. 2050313X1770137 ◽

Cited By ~ 1

Author(s):

Nayana Gunathilaka ◽

Shirom Siriwardana ◽

Lakmini Wijesooriya ◽

Gayana Gunaratne ◽

Nilanga Perera

Keyword(s):

Sri Lanka ◽

Abdominal Wall ◽

Anterior Abdominal Wall ◽

Parasitic Infection ◽

Human Infection ◽

Filarial Nematodes ◽

Human Dirofilariasis ◽

Proper Diagnosis ◽

Human Infections ◽

Controlling Measures

Objective: Dirofilariasis is a parasitic infection caused by filarial nematodes belonging to the genus Dirofilaria. Human dirofilariasis due to Dirofilaria repens has been widely reported from European countries. Sri Lanka is the most affected country in Asia with an infection rate of almost 60% in dog population. However, human infection of D. repens remains undiagnosed and many of the cases are not scientifically documented. Therefore, the objective of the present investigation is to document the presence of dirofilariasis infections in humans. Method: A 1 year and 10 months old boy from Ragama, Gampaha District, Western Province of Sri Lanka, was presented to a private hospital with a painless, non-pruritic and ill-defined subcutaneous nodule on his right hypochondrial region of the anterior abdominal wall for 1 week. On examination, there was a non-tender swelling measuring 2 cm × 2 cm in the anterior abdominal wall, with surrounding mild redness. The patient was referred for ultrasound confirmation. Results: The ultrasound scan revealed a hypoechoic nodular lesion measuring 11 mm × 6 mm in the anterior abdominal wall. Parasitological examination on the excised nodule confirmed the presence of D. repens measuring 10.5 cm in length having characteristic cuticle with longitudinal ridges. Conclusion: It is essential to record the human infections and increase the awareness about this infection, diagnostic tests and vector controlling measures, in order to reduce the disease prevalence through suppressing vector densities, proper diagnosis and patient care.

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First report of Leishmania (Viannia) lindenbergi causing tegumentary leishmaniasis in the Brazilian western Amazon region

Parasite ◽

10.1051/parasite/2019030 ◽

2019 ◽

Vol 26 ◽

pp. 30 ◽

Cited By ~ 7

Author(s):

Lilian Motta Cantanhêde ◽

Cristiane Batista Mattos ◽

Camila de Souza Ronconi ◽

Camila Patrício Braga Filgueira ◽

Cipriano Ferreira da Silva Júnior ◽

...

Keyword(s):

Dna Sequencing ◽

Species Identification ◽

Brazilian Amazon ◽

Human Infection ◽

Amazon Region ◽

Clinical Samples ◽

Tegumentary Leishmaniasis ◽

Brazilian Amazon Region ◽

Initial Description ◽

Human Infections

Tegumentary Leishmaniasis (TL) in the Brazilian Amazon region is associated with several Leishmania species. In this report, we describe two cases of TL related to Leishmania lindenbergi occurring in different locations of Rondônia state. After clinical diagnosis, lesion samples were collected for parasitological diagnoses via direct microscopic visualization, parasite isolation, and PCR. PCR reactions were positive in both clinical samples. Parasite isolation was possible for both patients, and isolates were submitted to species identification by isoenzyme electrophoresis and DNA sequencing. This report is the first to describe human infections caused by L. lindenbergi since the initial description and record of human infection by this species in 2002.

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Gnathostomatidae nematode parasite of Colomesus psittacus (Osteichthyes, Tetraodontiformes) in the Ilha de Marajó, Brazilian Amazon

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612017047 ◽

2017 ◽

Vol 26 (3) ◽

pp. 340-347

Author(s):

Raul Henrique da Silva Pinheiro ◽

Ricardo Luís Sousa Santana ◽

Francisco Tiago Vasconcelos Melo ◽

Jeannie Nascimento dos Santos ◽

Elane Guerreiro Giese

Keyword(s):

Digestive Tract ◽

Excretory Pore ◽

Brazilian Amazon ◽

The Body ◽

Anterior Region ◽

Intermediate Hosts ◽

The Third ◽

Nematode Larvae ◽

Third Stage ◽

Raw Fish

Abstract The genus Gnathostoma comprises 17 species, whose adult specimens are found in the stomach serosa of animals that consume raw fish; some species of the genus are zoonotic agents. The present study describes the presence of a nematode (Gnathostomatidae) parasitizing the digestive tract of Colomesus psittacus in the Ilha de Marajó in the eastern Brazilian Amazon. Thirty specimens of C. psittacus were collected in the municipality of Soure, Ilha de Marajó, state of Pará, Brazil, transported to the laboratory, necropsied and the helminths were collected and fixed. Of the 30 fish that were studied, 16.67% were parasitized with nematodes. The nematode larvae found encysted in the intestinal serosa have anterior region with two lips, each with a pair of papillae; a cephalic bulb armed with six rows of discontinuous spines; four cervical sacs; a claviform esophagus; cuticular striations along the body; a simple excretory pore; and a short tail ending in a mucron. These morphological structures are diagnostic characters of the genus Gnathostoma, whose adults parasitize the stomach of carnivorous mammals and, rarely, the stomach of fish. However, fish, amphibians, reptiles, and birds are intermediate hosts of the third-stage larvae (L3), and humans may act as accidental hosts.

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Organoids to Dissect Gastrointestinal Virus–Host Interactions: What Have We Learned?

Viruses ◽

10.3390/v13060999 ◽

2021 ◽

Vol 13 (6) ◽

pp. 999

Author(s):

Sue E. Crawford ◽

Sasirekha Ramani ◽

Sarah E. Blutt ◽

Mary K. Estes

Keyword(s):

Cell Types ◽

Human Infection ◽

Viral Pathogens ◽

Host Interactions ◽

Complex Interactions ◽

Microbe Interactions ◽

Host Microbe Interactions ◽

Human Intestinal Epithelium ◽

Human Viruses ◽

Human Infections

Historically, knowledge of human host–enteric pathogen interactions has been elucidated from studies using cancer cells, animal models, clinical data, and occasionally, controlled human infection models. Although much has been learned from these studies, an understanding of the complex interactions between human viruses and the human intestinal epithelium was initially limited by the lack of nontransformed culture systems, which recapitulate the relevant heterogenous cell types that comprise the intestinal villus epithelium. New investigations using multicellular, physiologically active, organotypic cultures produced from intestinal stem cells isolated from biopsies or surgical specimens provide an exciting new avenue for understanding human specific pathogens and revealing previously unknown host–microbe interactions that affect replication and outcomes of human infections. Here, we summarize recent biologic discoveries using human intestinal organoids and human enteric viral pathogens.

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Morphological and Phylogenetic Analysis of Eustrongylides sp. and Gnathostoma spinigerum Parasitizing the Asian Swamp Eel Monopterusalbus in China

Pathogens ◽

10.3390/pathogens10060711 ◽

2021 ◽

Vol 10 (6) ◽

pp. 711

Author(s):

Sixin Zhang ◽

Guangping Huang ◽

Liang Li ◽

Xianyong Liu ◽

Xiaoli Tang ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Coi Gene ◽

Molecular Characteristics ◽

Mean Intensity ◽

Gnathostoma Spinigerum ◽

Zoonotic Parasite ◽

Third Stage ◽

Parasite Infections ◽

Asian Swamp Eel ◽

Swamp Eel

Nematode infections transmitted to humans by the consumption of wild or cultured eels are increasingly being reported. In the present study, 120 Asian swamp eel, Monopterus albus (Zuiew), individuals collected from China were examined for parasite infections, and 78 larval nematodes were isolated. Morphological and molecular characteristics, including sequence and phylogenetic analysis of the internal transcribed spacer (ITS) and cytochrome c oxidase subunit I (COI) gene regions, were employed to identify these nematodes at the lowest taxonomic level possible. Asian swamp eel was infected with two zoonotic parasite taxa: Gnathostoma spinigerum advanced third-stage larvae, with 6.67% prevalence and mean intensity = 1.25, and Eustrongylides sp. fourth-stage larvae, with 26.67% prevalence and mean intensity = 2.13. These findings evidence the need to enhance public hygiene and food safety awareness toward eel consumption

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The immature stages of Smicridea (Rhyacophylax) gladiator Flint 1978 (Trichoptera: Hydropsychidae), with notes on distribution and bionomics

Zootaxa ◽

10.11646/zootaxa.4358.2.10 ◽

2017 ◽

Vol 4358 (2) ◽

pp. 375

Author(s):

GLEISON ROBSON DESIDÉRIO ◽

ANA MARIA PES ◽

NEUSA HAMADA ◽

JORGE LUIZ NESSIMIAN

Keyword(s):

Amazon Basin ◽

New Records ◽

Brazilian Amazon ◽

First Record ◽

Immature Stages ◽

Life Stages ◽

State Information ◽

Amazonas State

Immature stages of many Brazilian Smicridea species remains unknown, and efforts to describe all life stages are required. In this paper, the larva and pupa of Smicridea (Rhyacophylax) gladiator Flint 1978, associated with adults through the metamorphotype method, are described and illustrated. In addition, the known distribution of this species is extended in the Brazilian Amazon Basin with new records from Amazonas state and the first record in Pará state. Information about its bionomics is also provided.

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Net nitrogen mineralization and net nitrification rates in soils following deforestation for pasture across the southwestern Brazilian Amazon Basin landscape

Oecologia ◽

10.1007/s004420050157 ◽

1997 ◽

Vol 110 (2) ◽

pp. 243-252 ◽

Cited By ~ 100

Author(s):

Christopher Neill ◽

Marisa C. Piccolo ◽

Carlos C. Cerri ◽

Paul A. Steudler ◽

Jerry M. Melillo ◽

...

Keyword(s):

Nitrogen Mineralization ◽

Amazon Basin ◽

Brazilian Amazon ◽

Net Nitrification ◽

Net Nitrogen Mineralization

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Scanning electron microscope studies of miracidia suggest introgressive hybridization between Schistosoma haematobium and S. haematobium x S. mattheei in the Eastern Transvaal

Journal of Helminthology ◽

10.1017/s0022149x0001138x ◽

1988 ◽

Vol 62 (2) ◽

pp. 141-147 ◽

Cited By ~ 6

Author(s):

F. J. Kruger ◽

V. L. Hamilton-Attwell

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Schistosoma Haematobium ◽

Introgressive Hybridization ◽

Human Infection ◽

Infection Rates ◽

High Prevalence ◽

Scanning Electron

ABSTRACTSchistosoma haematobium miracidia were collected from a locality with a high prevalence of human infection with the animal parasite, S. mattheei, which hybridizes with S. haematobium, and from 2 localities with negligible infection rates. The terebratoria of the miracidia from these localities were compared with each other, with laboratory maintained S. haematobium and with four populations of S. mattheei by means of scanning electron microscopy. It was found that the terebratorial membrane of certain of the S. haematobium miracidia from the locality with a high S. mattheei prevalence in humans, resembled the more intricate membrane of S. mattheei. This suggests introgressive hybridization between S. haematobium and S. haematobium x S. mattheei.

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