Paragonimus and paragonimiasis in West and Central Africa: unresolved questions.

Paragonimiasis, human lung fluke disease, is a foodborne anthropozoonosis caused by the trematodes assigned to Paragonimus and is regarded by the World Health Organization as a Neglected Tropical Disease (NTD). The life cycle of this medically important parasite centres on a complex freshwater biological community that includes two intermediate hosts: a mollusc and a decapod, usually a brachyuran. Although there is a perception that the biology, symptoms, diagnosis and treatment of Paragonimus is well understood, in reality, this is not the case, especially in Africa. Much remains unknown concerning the life-cycle of the parasite, its transmission, the current epidemiology of the disease, diagnosis and the effectiveness of treatment. Furthermore, cases of paragonimiasis may be misdiagnosed as resistant tuberculosis (TB) because of the similar pulmonary symptoms and no remission after anti TB therapy. The endemic foci of human paragonimiasis in Africa have been reported mainly in the forest zones of Upper Guinea (Liberia, Guinea and Ivory Coast) and Lower Guinea (Nigeria, Cameroon, Equatorial Guinea and Gabon). Despite the perceived medical importance of paragonimiasis, relatively little attention has been paid to this NTD since its discovery in Africa in the 1960s. This review focuses on the current understanding of the life cycle and transmission of Paragonimus in Africa, discusses its diagnosis and public health importance and highlights many outstanding gaps in the knowledge that still exist for this NTD.

Bioaccumulation and public health implications of trace metals in edible tissues of the crustaceans Scylla serrata and Penaeus monodon from the Tanzanian coast.

The coastal population in East Africa is growing rapidly but sewage treatment and recycling facilities in major cities and towns are poorly developed. Since estuarine mangroves are the main hotspots for pollutants, there is a potential for contaminants to accumulate in edible fauna and threaten public health. This study analysed trace metals in muscle tissues of the giant mud crabs (Scylla serrata) and the giant tiger prawns (Penaeus monodon) from the Tanzanian coast, in order to determine the extent of bioaccumulation and public health risks. A total of 180 samples of muscle tissues of S. serrata and 80 of P. monodon were collected from nine sites along the coast. Both species showed high levels of trace metals in the wet season and significant bioaccumulation of As, Cu and Zn. Due to their burrowing and feeding habits, mud crabs were more contaminated compared to tiger prawns sampled from the same sites. Apart from that, the measured levels of Cd, Cr and Pb did not exceed maximum limits for human consumption. Based on the current trend of fish consumption in Tanzania (7.7 kg/person/year), the measured elements (As, Cd, Co, Cu, Mn, Pb and Zn) are not likely to present health risks to shellfish consumers. Nevertheless, potential risks of As and Cu cannot be ruled out if the average per capita consumption is exceeded. This calls for strengthened waste management systems and pollution control measures.

Fabrication of nano-mosquitocides using chitosan from crab shells: Impact on non-target organisms in the aquatic environment.

Mosquitoes are arthropods of huge medical and veterinary relevance, since they vector pathogens and parasites of public health importance, including malaria, dengue and Zika virus. Currently, nanotechnology is considered a potential eco-friendly approach in mosquito control research. We proposed a novel method of biofabrication of silver nanoparticles (AgNP) using chitosan (Ch) from crab shells. Ch-AgNP nanocomposite was characterized by UV-vis spectroscopy, FTIR, SEM, EDX and XRD. Ch-AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi obtaining LC50 ranging from 3.18 ppm (I) to 6.54 ppm (pupae). The antibacterial properties of Ch-AgNP were proved against Bacillus subtilis, Klebsiella pneumoniae and Salmonella typhi, while no growth inhibition was reported in assays conducted on Proteus vulgaris. Concerning non-target effects, in standard laboratory considtions the predation efficiency of Danio rerio zebrafishes was 68.8% and 61.6% against I and II instar larvae of A. stephensi, respectively. In a Ch-AgNP-contaminated environment, fish predation was boosted to 89.5% and 77.3%, respectively. Quantitative analysis of antioxidant enzymes SOD, CAT and LPO from hepatopancreas of fresh water crabs Paratelphusa hydrodromous exposed for 16 days to a Ch-AgNP-contaminated aquatic environment were conducted. Notably, deleterious effects of Ch-AgNP contaminating aquatic enviroment on the non-target crab P. hydrodromous were observed, particularly when doses higher than 8-10ppm are tested. Overall, this research highlights the potential of Ch-AGNP for the development of newer control tools against young instar populations of malaria mosquitoes, also highlighting some risks concerned the employ of nanoparticles in aquatic environments.

A case of pulmonary paragonimiasis with involvement of the abdominal muscle in a 9-year-old girl.

In Korea, many people enjoy eating raw or underkooked freshwater crayfish and crabs which unfortunately may cause paragonimiasis. Here, we describe a case of pulmonary and abdominal paragonimiasis in a 9-year-old girl, who presented with a 1-month history of abdominal pain, especially in the right flank and the right inguinal area, with anorexia. A chest radiograph revealed pleural effusion in both lungs, and her abdominal sonography indicated an inflammatory lesion in the right psoas muscle. Peripheral blood analysis of the patient showed hypereosinophilia (66.0%) and an elevated total serum IgE level (>2,500 IU/ml). The pleural effusion tested by ELISA were also positive for antibodies against paragonimiasis. Her dietary history stated that she had ingested raw freshwater crab, 4 months previously. The diagnosis was pulmonary paragonimiasis accompanied by abdominal muscle involvement. She was improved after 5 cycles of praziquantel treatment and 2 times of pleural effusion drainage. In conclusion, herein, we report a case of pulmonary and abdominal paragonimiasis in a girl who presented with abdominal pain and tenderness in the inguinal area.

Assessment of crab fishermen's exposure to rabies virus in a typical Amazonian community.

Outbreaks of human rabies transmitted by hematophagous bats occurred in 2018 in Pará state, Brazil, eastern Amazon, after 12 years of no record of the disease. Thus, it is necessary to understand the epidemiological characteristics of these attacks to protect the local population. This study aimed to characterize the bat bite populations in the municipality of São João da Ponta, Pará State, Brazil, in 2013-2015. The Notifiable Diseases Information System (SINAN) database was used to identify the five individuals who sought medical care during the study period (seeds). Other individuals who were attacked during the same period but did not seek medical care (n = 61) were reached by snowball sampling, and a descriptive analysis was performed based on information obtained from questionnaires. Majority of the interviewees were men (92.4%; 61/66) and adults aged 20-50 years (69.9%; 46/66) and had <4 years of formal school education (86.3%; 57/66). Additionally, most of them were rural residents (92.4%; 61/66) and crab fishermen (79.3%; 53/66). The interviewees (92.4%; 61/66) identified mangroves of the Mãe Grande de Curuçá extractive reserve, where groups of fishermen sometimes gather for several days for crab fishing, often living in improvised dwellings without walls and covered by tarps or straw (88.8%; 56/66), conducive to attacks by vampire bats. Overall, 42.4% (28/66) of the participants had been bitten more than four times throughout their life. The median number of attacks over the participant's lifetime was 3.11 (range, 1-23). Participants were unaware of the risk of contracting rabies from the bite (95.4%; 65/66). These results suggest that vampire bat attacks are essentially an occupational hazard in the study region. Moreover, for each reported attack, there were at least 12.2 unreported cases. Thus, the study highlights the need to develop strategies for prophylactic treatment of this population.

Non-Fatal Injuries and Injury Treatment in the West Coast Dungeness Crab Fishery.

Objectives: Non-fatal injuries in the high risk US Dungeness crab fishery have been under-documented, despite their potential for lost work time and income, long-term disability, and early unwanted retirement. The Fishermen Led Injury Prevention Program (FLIPP) characterized injuries in this fishery, in order to identify work hazards and inform injury control measures.Methods: The FLIPP injury survey was completed by 426 fishermen in 23 Washington, Oregon, and California fishing ports prior to the 2015-2016 Dungeness crab season; 413 (97%) provided injury information for this analysis. Participants indicated whether they had been injured in the previous 12 months, described the injury, any treatments received, and whether the injury limited their ability to work.Results: Participants were mostly male (98%), more than half (56.6%) worked as deckhands, and reported considerable fishing experience (median = 14 years, interquartile range 5-27). Eighty-nine fishermen (21.5%) reported an injury incident in the past year, of which 49 (55.1%) were limiting. The 89 incidents yielded 102 injuries, of which nearly two-thirds were sprains/strains (23, 22.5%), surface wounds/bruises (17, 15.0%), cuts (18, 17.6%), or punctures (11, 10.8%). More severe injuries, including eight fractures, were rare. The majority of injuries received either no treatment (27, 26.5%) or first aid (35, 34.3%); clinical care was less common (22, 21.6%), and emergency care rare (3, 2.9%).Conclusion: One in five Dungeness crab fishermen reported an injury incident in the previous year. Most injuries were not severe and did not result in clinical care, but approximately half were work-limiting. Control measures must account for the remote and resource-limited workplace in commercial fishing.

Extra-pulmonary paragonimiasis with unusual arthritis and cutaneous features among a tourist returning from Gabon.

Paragonimiasis is a helminthic disease that affect accidentally man after consumption of raw or poorly cooked crustacean dishes. The clinical feature is represented mainly by pulmonary signs. Extra-pulmonary manifestations including arthritic and skin attempt remain less frequent. The case is described of a young white French woman who become infected with Paragonimus while travelling to Gabon for a tourist trip. Clinical presentation accounted for extensive recurrent pruritic urticarian subcutaneous induration, permanent assymetrical pauciarthritis associated with joint swelling, and marked eosinophilia. Diagnosis was reached using serological testing showing seroconversion for specific antibodies. The patient was cured with a single oral dose of praziquantel. Even if the condition is rare among tourists to endemic zones, it must be considered when hypereosinophilia occurs in the returning traveller and migrant.

Transmission of Onchocerca volvulus continues in Nyagak-Bondo focus of northwestern Uganda after 18 years of a single dose of annual treatment with ivermectin.

The objective of the study was to determine whether annual ivermectin treatment in the Nyagak-Bondo onchocerciasis focus could safely be withdrawn. Baseline skin snip microfilariae (mf) and nodule prevalence data from six communities were compared with data collected in the 2011 follow-up in seven communities. Follow-up mf data in 607 adults and 145 children were compared with baseline (300 adults and 58 children). Flies collected in 2011 were dissected, and poolscreen analysis was applied to ascertain transmission. Nodule prevalence in adults dropped from 81.7% to 11.0% (P < 0.0001), and mf prevalence dropped from 97.0% to 23.2% (P < 0.0001). In children, mf prevalence decreased from 79.3% to 14.1% (P < 0.0001). Parous and infection rates of 401 flies that were dissected were 52.9% and 1.5%, respectively, whereas the infective rate on flies examination by polymerase chain reaction (PCR) was 1.92% and annual transmission potential was 26.9. Stopping ivermectin treatment may result in onchocerciasis recrudescence.

Pathways for transmission of angiostrongyliasis and the risk of disease associated with them.

Angiostrongylus cantonensis, the rat lungworm, is a major cause of eosinophilic meningitis in humans. This short paper reviews what is known about the pathways of infection and assesses the probable importance of each in causing disease. Rats are the definitive hosts. People can become infected by eating, both deliberately and inadvertently, raw or under-cooked intermediate hosts (snails or slugs) or paratenic hosts such as freshwater shrimp, crabs and frogs. Food preparation prior to cooking can leave debris from which infection can also occur. It may be possible to become infected by consuming snail/slug slime (mucus) on produce or by transferring mucus from hands to mouth after handling snails/slugs. Infection from consuming drinking water contaminated by snails/slugs and infection via open wounds may be theoretically possible but no cases have been reported. The severity of the disease is probably related to the number of infective larvae ingested as well as to the precise location of the worms in the host and the host's inflammatory response. Strategies for reducing human infection should include snail and slug control to reduce chances of accidental ingestion, cooking of intermediate and paratenic hosts, and public education on food preparation.

[Paragonimus sp. in crabs and awareness of the educational community to aquatic ecosystems in La Miel and La Clara, Caldas, Antioquia]. / Paragonimus sp. en cangrejos y sensibilización de la comunidad educativa hacia los ecosistemas acuáticos de La Miel y La Clara, Caldas, Antioquia.

INTRODUCTION: Previous research has demonstrated the presence of Paragonimus spp. in crabs of three municipalities located in the Medellín river basin. To design a plan for the control and prevention of paragonimosis, parasite presence must be demonstrated in the upper area of the river, and an awareness campaign of its risks must involve the participation of the educational community in focusing attention on the local aquatic resources. OBJECTIVE: The presence of Paragonimus spp. metarcercariae was established in freshwater crabs from La Miel and La Clara streams, and an awareness campaign created public awareness to management of the aquatic ecosystems for risk reduction. MATERIALS AND METHODS: Nine crabs were collected from streams of La Miel and La Clara villages in 2007 and 2008. The crabs were indentified, sacrificed in the laboratory and examined for presence of Paragonimus spp. metacercariae. Five workshops were conducted with students of educational institutions of the two villages to improve the student perception of paragonimosis risks associated with the local streams. RESULTS: The crabs were identified as Hypolobocera bouvieri. One crab was found with Paragonimus spp. in La Miel. A mollusk, Aroapyrgus colombiensis, another host of the parasite was found in La Clara. That aquatic ecosystems are a great attraction for the local was well established. CONCLUSIONS: Foci of Paragonimus spp. flatworms are present in the upper area of Medellín river which includes Caldas. However, local school children were uninformed about the risk of paragonimosis associated with the local aquatic ecosystem. Therefore this province must be included in programs for prevention and control of paragonimosis. The prevalence of this disease recommends educational programs that promote awareness of local aquatic ecosystems and their parasitic inhabitants.

Rabies virus related to vampire bats (Desmodus rotundus) isolated from a crab-eating fox (Cerdocyon thous) in Southeast Brazil

In this study, rabies virus was isolated from a naturally infected crab-eating fox [Cerdocyon thous] in a rural area of São Paulo State, Brazil. The sample was positive for the standard techniques used for rabies diagnosis. The isolate was antigenically characterized using anti-nucleoprotein monoclonal antibodies. Studies on molecular epidemiology by patterns of nucleotide substitution in the nucleoprotein gene showed that the isolate was genetically homologous to the rabies variant maintained and transmitted by the common vampire bat Desmodus rotundus. This is the first report of detection of this variant from a crab-eating fox in Brazil and represents evidence of cross-species transmission. This was the unique report where this variant was isolated from a crab eating fox in Brazil.

Análise morfométrica de populações do caranguejo-uçá(Ucides Cordatus L. (Crustacea – Decapoda) em manguezais do litoral do Espírito Santo / Morphometric analysis of mangrove crab (Ucides Cordatus L. ) ( Crustacea –Decapoda) populations in Espírito Santo mangroves coastline

O caranguejo-uçá (Ucides cordatus) é um crustáceo (Decápoda: Brachyura) de grande valor cultural, biológico e comercial em todo Espírito Santo. Contudo, ainda há uma grande lacuna de conhecimentos acerca de sua biologia. Com o intuito de minimizar essa carência, o presente trabalho realizou um estudo sobre a caracterização morfológica de três populações do caranguejo-uçá (Ucides cordatus L.) em manguezais do Espírito Santo. Foram analisadas quatro características morfométricas em 172 indivíduos machos, coletados nas cidades de São Mateus (N=62), Vitória (N=60) e Anchieta (50). Foi observada diferença significativa entre as três populações (p<0,01) por meio de uma Análise de Variância Multivariada. O maior grau de similaridade foi encontrado entre as populações de São Mateus (Norte) e Anchieta (Sul), de modo que a população de Vitória (Centro) foi agrupada separadamente, evidenciando-se divergência entre essa população e as demais. Os resultados sugerem pressões de seleção diferentes nas populações do interior em relação à população da capital, o que pode estar relacionado a uma maior ação antrópica nas populações da capital.