Distribution of metacercariae in freshwater crabs in relation to Paragonimus infection of children in Liberia, West Africa (original) (raw)
Related papers
Journal of Parasitic Diseases, 2021
Paragonimiasis, the disease caused by Paragonimus westermani, is transmitted primarily by freshwater crabs Sundathelphusa philippina in the Philippines. Human infection has been recorded, but there is a dearth of published information on the extent of infection in animal reservoirs, particularly in crabs and snails. This study aimed to investigate the infection status and risk factors of P. westermani in freshwater crabs and melaniid snails collected in an endemic village along Cadacan River in Irosin, Sorsogon, where human cases of paragonimiasis were previously reported. A total of 246 freshwater crabs (118 females, 128 males) were dissected, and the gills, muscles, gonads, and viscera were examined for the presence of metacercariae; of which, 41.87% were found infected. The metacercariae were recovered from the gills (100%) and muscle tissues (7.3%) of infected crabs. Male crabs were more likely to be infected (49.22%) than female crabs (33.90%) (p \ 0.05). Moreover, 70.87% of crabs showed low parasite intensity levels at B 30 metacercariae/g tissue. A negative weak correlation was observed between parasite intensity and crab weight and carapace length, i.e., highly infected crabs were found to be smaller in size. Meanwhile, only 12% of the 150 melaniid snails collected were positive with cercariae with Tarebia granifera and Jagora asperata as the most infected species. Household survey conducted revealed that some knowledge, attitudes, and practices of the locals contribute to the sustained transmission of the parasite in this endemic area. These findings revealed that P. westermani is still prevalent among intermediate hosts and that some social and environmental factors contributed to the sustained parasite transmission in this endemic community.
Paragonimus ohirai Metacercariae in Crabs Collected along the Arakawa River in Tokyo, Japan
Journal of Veterinary Medical Science, 2004
Brackish water crabs infected with Paragonimus ohirai metacercariae have been reported in various regions in Japan. However, infected crabs have not been identified in Tokyo. We therefore collected the crab, Chiromantes dehaani, between August 2002 and July 2003 from 12 locations along the Arakawa River that flows through Tokyo. Of the 922 captured crabs, 177 (19%) from 6 l ocations were infected with Paragonimus metacercariae. The prevalence of metacercariae at these 6 locations ranged from 5 to 89%. The number of metacercariae per infected crab ranged from 1 to 190, with an average of 13.1. The morphological features of the metacercariae and of adult worms recovered from test rats infected with metacercariae showed that the metacercariae in the infected crabs were P. ohirai Miyazaki, 1939. The ITS2 sequence data support this conclusion. This paper is the first description of P. ohirai infection of crabs in Tokyo.
Parasitology Research, 2007
In several mountainous regions of Northeastern India, foci of Paragonimus infection reportedly involving species that are known to prevail in China have been identified. The present study was undertaken to demonstrate the surface fine topography and sequence analysis of the ribosomal deoxyribonucleic acid (rDNA; second internal transcribed spacer, ITS2) of the metacercarial stages of the lung fluke collected from a mountain stream of the area (Miao, Changlang District in Arunachal Pradesh). The encysted metacercariae were oval in shape and had a smooth surface. The newly excysted metacercaria had a ventral sucker larger than the oral; the body surface was covered with numerous single-pointed and thorn-like tegumentary spines, of which those on the anterior part of the body were bigger in size and showed a gradual reduction in length and number towards the posterior end; dome-shaped papillae in variable numbers were seen around the rim of the oral sucker and were sparsely distributed all over the body surface. The polymerase chain reaction-amplified rDNA ITS2 sequences of the metacercariae were aligned with known sequences for the various species of Paragonimus, and the expectation value was found to be most significant with P. westermani, revealing an absolute match. The surface topography including the number and distribution of papillae and spination patterns and the ITS2 sequences of the metacercariae strongly suggest that the Paragonimus species, prevalent in the region of India, is in fact P. westermani. P. pulmonalis (Baelz 1880 P. ohirai Miyazaki 1939; P. iloktsunensis Chen 1940; P. skrjabini Chen 1959; P. miyazaki Kamo et al. 1961 and P. heterotremus Chen and Hsia 1964, all reported to be occurring in Asia, P. africanus and P. uterobilateralis Voelker and Vogel 1965 in Africa and P. mexicanus Miyazaki and Ishii 1968 in America are considered pathogenic to man. While P. westermani is distributed mostly in Asia, P. heterotremus is the predominant causative agent of paragonimiasis in Thailand (Blair et al. 1999a, b).
Étude épidémiologique sur Paragonimus sp. Dans Le Sud Cameroun
1995
ÉTUDE ÉPIDÉMIBLOGIQUE D'UNE DISTOMATOSE À PARAGONIMUS' SP. AU SUD-CAMEROUN Par G. OLLIVIER (l), M. BOUSSINESQ (2), J. L. ALBARET (3), N. CUMBERLIDGE (4), K. FARHATI (3, J. P. CHIPPAUX (6) & C. BAYSSADE-DUFOUR (3) (7) Epidemiological study on Paragonimus sp. in south Cameroon. Summary: A study was carried out in 1993 in south Cameroon in order to assess the changes in the incidence rate of human paragonimiasis, and to get information on the transmission pattern of Paragonimus sp. Two human cases have been recorded, and one dog was found infected in the Ntem Valley. The results suggest that a decrease .of the incidence rate of paragonimiasis occurred in humans and animals. Paragonimus metacercariae were found in three species of freshwater crabs: Sudanonautes africanus, S. aubryi et S. granulatus, the latter being a new host. Prevalence of infection in crabs increased southerly, and signifcant seasonal changes were found. Two cats were infested with metacercariae from S. africanus, and studies are in progress to identifv the parasite@) at a specific level. Résumé : Une étude a été menée en I993 au sud-Cameroun en vue d'évaluer I'évolution de l'incidence de la paragonimose humaine et de préciser les modalités de la transmission de Paragonimus sp. Deux cas humains ont été dt'pistés et un chien a kté trouvé infesté dans le bassin du Ntem. L'incidence de l'infestation chez l'homme et les animaux sauvages semble avoir chuté durant la dernière décennie. Des métacercaires de Paragonimus sp. ont ét& trouvées chez trois espPces de crabes : Sudanonautes africanus, S. aubryi et S. granulatus, cette derni8re constituant un nouvel hôte. Un gradient géographique et des variations saisonnières du taux d'infestation des crabes ont été mis en évidence. Des mgtacercaires provenant de S. africanus ont permis Pinfestation expérimentale de deux chats et l'identification des parasites au niveau spécifique est en cours.
ISRN Infectious Diseases, 2013
This work was aimed at assessing the prevalence of paragonimiasis and crab-eating behavior in Southeastern Nigeria. Sputum examinations and questionnaire administration were carried out. Prevalence was 13.2% and was significantly higher among females (14.6%) than males (11.2%) (P<0.05). Overall, 77.2% of respondents across the communities eat crabs, and this was comparable between males (76.4%) and females (77.6%) (P>0.05). The prevalence was comparable between the two ethnocultural groups and between communities within each ethnocultural group (P>0.05for both tests). The mean age of crab eaters was 43 years, while that of noncrab eaters was 26 years. Many (46.3%) infected individuals presented low intensity infections (1–50 eggs/ova per 5 mL−1sputum), while 28.8% and 23.8% presented moderate (51–100 eggs/ova per 5 mL−1sputum) and high (above 100 eggs/ova per 5 mL−1sputum) intensity infections, respectively. Infection risk among weekly eaters of crabs was 3 times higher tha...
Detection of Paragonimus mexicanus (Trematoda) metacercariae in crabs from Oaxaca, Mexico
Metacercariae of Paragonimus mexicanus were collected in crabs Tehuana guerreroensis (Rathbun, 1933) in the municipality of Putla, Oaxaca, Mexico. Metacercariae were found in 20.8% of the crabs collected, with an average of 1.9 metacercarie per crab. Stained metacercariae showed the specific characteristics of P. mexicanus by morphology and sequencing a fragment of the 28S ribosomal gene obtained by PCR. These findings reveal that T. guerreroensis is an intermediate host for P. mexicanus; this new report is relevant considering the potential risk of transmission in the states of Oaxaca and Guerrero, Mexico.
Presence of Paragonimus species within secondary crustacean hosts in Bogotá, Colombia
Revista Colombiana de Ciencias Pecuarias, 2019
Background: Paragonimus spp. are trematode parasites that infect human populations worldwide. It is believed that infection rates within Asia reach five to ten percent of the total population. Three of the largest areas of possible infection are Asia, Central and South America as well as Africa, where the total population at risk is estimated to be 293 million people. Humans are infected via ingestion of raw or undercooked decapod crustaceans. Objective: To identify the presence of Paragonimus spp. in crabs from Bogotá, Colombia. Methods: The native crab Neostrengeria macropa and the aquatic invasive crayfish Procambarus clarkii in Bogotá, Colombia, were collected from local markets, pet stores and waterways and dissected to assess the presence of Paragonimus spp. Results: The native crab species, N. macropa (n=29) had an infection prevalence of 17.2%, while the invasive crayfish species, P. clarkii (n=22), had a prevalence of 36.4% combined from both field captured animals and pur...
2017
Seven Wistar rats (Rattus norvegicus) were experimentally infected with Paragonimus mexicanus metacercariae, obtained from organs and tissues of freshwater crabs (Brachyura: Pseudothelphusidae) collected from the Caribbean of Costa Rica. Four rodents were infected orally and three by intraperitoneal injection. Eggs of P. mexicanus were found in a stool sample five months post-infection in one of the rodents infected intraperitoneally. Five out of seven rats, developed worms, three inmature, and two adult ones. Worms obtained from rats infected intraperitoneally showed development of gonads with presence of eggs in the uterus. Although the recovery rate of worms was low (media: 2.3%), the susceptibility of these rodents to this trematode species was demonstrated as mature adults of P. mexicanus were obtained from Wistar rats. The use of Wistar rats as an animal model for experimental infections in further investigations is recommended.