Endemicity of Paragonimus and paragonimiasis in Sub-Saharan Africa: A systematic review and mapping reveals stability of transmission in endemic foci for a multi-host parasite system

Paragonimiasis

Paragonimiasis is a zoonotic disease caused by lung flukes of the genus Paragonimus. Humans usually become infected by eating freshwater crabs or crayfish containing encysted metacercariae of these worms. However, an alternative route of infection exists: ingestion of raw meat from a mammalian paratenic host. Adult worms normally occur in pairs in cysts in the lungs from which they void their eggs via air passages. The pulmonary form is typical in cases of human infection due to P. westermani, P. heterotremus, and a few other species. Worms may occupy other sites in the body, notably the brain, but lung flukes have made their presence felt in almost every organ. Ectopic paragonimiasis is particularly common when infection is due to members of the P. skrjabini complex. Human paragonimiasis occurs primarily in the tropics and subtropics of Asia, Africa, and the Americas, with different species being responsible in different areas (Table 6.1).

Immunoblotting Identification of Diagnostic Antigens of Paragonimus westermani Type 1 for the Detection of Human Pulmonary Paragonimiasis in North East India

Human pulmonary paragonimiasis, an emerging concern in North East India, frequently masquerades as pulmonary tuberculosis due to clinical and radiological similarities, leading to diagnostic challenges. This research aimed to harness the immunoblotting technique to discern immunodiagnostic protein antigens from both adult worm and excretory-secretory (ES) extracts of the prevalent Paragonimus westermani type 1 in Arunachal Pradesh, North East India. We studied the time kinetics of immunoreactive patterns in relation to the duration of infection in rodent models. Immunoblot analyses were also conducted using sera from ELISA-positive patients confirmed with paragonimiasis, facilitating the selection of antigenic extracts with diagnostic potential. Further, ES protein antigens were subjected to 2D immunoblot analysis and immunoreactive protein spots identified using MALDI-TOF MS. The immunoreactivity patterns of ES antigens with sera of paragonimiasis-positive patients were detailed, and specific immunoreactive protein antigens were pinpointed using peptide mass fingerprinting (MALDI-TOF). This work underscores the enhanced diagnostic accuracy when combining ELISA with immunoblotting for pulmonary paragonimiasis in regions like North East India, marked by co-existing helminth infections.

Emerging and Re-Emerging Parasitic Infections of the Central Nervous System (CNS) in Europe

In a rapidly evolving global landscape characterized by increased international travel, migration, and ecological shifts, this study sheds light on the emergence of protozoal and helminthic infections targeting the central nervous system (CNS) within Europe. Despite being traditionally associated with tropical regions, these infections are progressively becoming more prevalent in non-endemic areas. By scrutinizing the inherent risks, potential outcomes, and attendant challenges, this study underscores the intricate interplay between diagnostic limitations, susceptibility of specific population subsets, and the profound influence of climate fluctuations. The contemporary interconnectedness of societies serves as a conduit for introducing and establishing these infections, warranting comprehensive assessment. This study emphasizes the pivotal role of heightened clinician vigilance, judicious public health interventions, and synergistic research collaborations to mitigate the potential consequences of these infections. Though rare, their profound impact on morbidity and mortality underscores the collective urgency required to safeguard the neurological well-being of the European populace. Through this multifaceted approach, Europe can effectively navigate the complex terrain posed with these emergent infections.

Trends in Paragonimiasis Global Research: Bibliometric Analysis of a Neglected Food-Borne Parasite

Background

Paragonimus is a genus of parasitic flatworms known as lung flukes that cause the parasitic disease paragonimiasis in humans and other mammals. We aimed to use bibliometric analysis to identify the global characteristics and temporal trends of published literature about paragonimiasis.

Methods

Using the Web of Science database, we identified all original articles on paragonimiasis 1997 to 2022. After collecting the bibliographic and citation data, keywords, citation networks, and co-citations pertaining to paragonimiasis was carried out using the VOSviewer program.

Results

The study identified 563 paragonimiasis articles published in 250 journals. Publications in paragonimiasis research have been cited 6190 times and 2803 times without self-citations. The years with the most publications were 2013, 2016, and 2021. The minimal threshold for analysis was met by 19 of the 52 countries investigated. The study included 19 items, yielding 170 links between countries. The total strength of these links was discovered to be 104772. The journal with the most publications in this category was Parasitology Research (n=31). The most frequently used terms in paragonimiasis study were "paragonimiasis", "Paragonimus westermanii", and "lung-fluke."

Conclusion

The study concluded by providing an overview of the paragonimiasis research field, including current trends, development, and researcher collaboration. By addressing gaps in this bibliometric analysis and increasing collaboration, stake-holders could strengthen their strategies to effectively combat paragonimiasis and improve public health outcomes.

A checklist and key to the Ivorian freshwater crabs, with the description of a new species of Liberonautes Bott, 1955 (Brachyura: Potamoidea: Potamonautidae)

A new freshwater crab species of Liberonautes Bott, 1955 from Mt. Tonkori in the Upper Guinea rainforest in Côte d'Ivoire, West Africa is described. Liberonautes constantini n. sp. is morphologically distinct from other species of this genus found in Côte d'Ivoire and the neighboring countries. The new species is recognised by a unique combination of morphological characters of the carapace, thoracic sternum, major cheliped, and adult male first gonopod. Illustrations of L. constantini n. sp. are provided and differences from congeners found elsewhere in West Africa are discussed. The addition of L. constantini n. sp. raises the number of species of freshwater crabs known to occur in Côte d'Ivoire to seven. An updated checklist and key are provided to the Ivorian species of freshwater crabs, and their conservation status is discussed.

A Case of Spontaneous Pneumothorax due to Paragonimiasis in North America with Literature Review

The species, Paragonimus kellicotti , causes human paragonimiasis in North America. As a foodborne disease, human infection with P. kellicotti occurs after eating raw or undercooked crayfish containing metacercariae. Many risk factors have been described in the literature, including young adult age, male, alcohol consumption, outdoor activities involving rivers within Missouri, and ingesting raw or partially cooked crayfish. Here, we report a case of a 41-year-old male with a 5-year history of cough who presented with acute shortness of breath. Further workup showed mild eosinophilia and spontaneous pneumothorax. A definitive diagnosis was made with a lung biopsy, which showed P. kellicotti eggs. Further questioning revealed that the patient took a hunting and river rafting trip on a river in Missouri 5 years ago, though the history was negative for any crayfish consumption. Paragonimiasis should be considered in those with associated clinical features, including cough and eosinophilia, with a history of a river raft float trip in Missouri, even if the history is negative for crayfish ingestion or travel.

Where Have All the Diagnostic Morphological Parasitologists Gone?

Advances in laboratory techniques have revolutionized parasitology diagnostics over the past several decades. Widespread implementation of rapid antigen detection tests has greatly expanded access to tests for global parasitic threats such as malaria, while next-generation amplification and sequencing methods allow for sensitive and specific detection of human and animal parasites in complex specimen matrices.

Pulmonary Paragonimiasis in Native Community, Esmeraldas Province, Ecuador, 2022

Paragonimiasis is a food-borne infection caused by several species of the Paragonimus fluke. Clinical manifestations can mimic tuberculosis and contribute to diagnostic delay. We report a cluster of paragonimiasis in a community in Ecuador, where active surveillance was set up after detection of the first 2 cases.

General overview of the current status of human foodborne trematodiasis

Foodborne trematodes (FBT) of public health significance include liver flukes (Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Fasciola hepatica and F. gigantica), lung flukes (Paragonimus westermani and several other Paragonimus spp.) and intestinal flukes, which include heterophyids (Metagonimus yokogawai, Heterophyes nocens and Haplorchis taichui), echinostomes (Echinostoma revolutum, Isthmiophora hortensis, Echinochasmus japonicus and Artyfechinostomum malayanum) and miscellaneous species, including Fasciolopsis buski and Gymnophalloides seoi. These trematode infections are distributed worldwide but occur most commonly in Asia. The global burden of FBT diseases has been estimated at about 80 million, however, this seems to be a considerable underestimate. Their life cycle involves a molluscan first intermediate host, and a second intermediate host, including freshwater fish, crustaceans, aquatic vegetables and freshwater or brackish water gastropods and bivalves. The mode of human infection is the consumption of the second intermediate host under raw or improperly cooked conditions. The major pathogenesis of C. sinensis and Opisthorchis spp. infection includes inflammation of the bile duct which leads to cholangitis and cholecystitis, and in a substantial number of patients, serious complications, such as liver cirrhosis and cholangiocarcinoma, may develop. In lung fluke infections, cough, bloody sputum and bronchiectasis are the most common clinical manifestations. However, lung flukes often migrate to extrapulmonary sites, including the brain, spinal cord, skin, subcutaneous tissues and abdominal organs. Intestinal flukes can induce inflammation in the intestinal mucosa, and they may at times undergo extraintestinal migration, in particular, in immunocompromised patients. In order to control FBT infections, eating foods after proper cooking is strongly recommended.

Lung flukes of the genus Paragonimus: ancient and re-emerging pathogens

The title of this article refers to Table 1 in Zhou (2022, Infectious diseases of poverty: progress achieved during the decade gone and perspectives for the future. Infectious Diseases of Poverty 11, 1), in which it is indicated that Paragonimus species, like many other foodborne trematodes, are ancient pathogens that are also re-emerging to cause disease in modern times. This article provides a general overview of Paragonimus species and the disease they cause. This is followed by comments on several specific topics of current interest: taxonomy and distribution of members of the genus; details of the life cycle; global and regional prevalence of paragonimiasis; genomics of lung flukes and possible effects of global environmental change. Unresolved questions relating to these topics are discussed and gaps in knowledge identified.