The prevalence of Linguatula serrata nymphs in goats slaughtered in Kerman slaughterhouse, Kerman, Iran

Prevalence and risk factors of Linguatula spp. in slaughter animals in Tabriz, Iran, and methods for nymphal stage inactivation

Linguatula is a food born zoonotic parasite in which carnivores and herbivores serve as final and intermediate hosts, respectively. Human infection with Linguatula spp. occurs following consumption of raw or undercooked infected internal organs of the intermediate host and/or consumption of water and/or vegetables contaminated with eggs released from final hosts. The aim of this study was to determine prevalence and risk factors of Linguatula spp. in sheep, cattle, buffalo, goats and camels slaughtered at the Tabriz abattoir, Iran. In addition, effect of temperature and sodium chloride (NaCl) on survival time of Linguatula spp. nymphs was assessed. For this purpose, 25,520 mesenteric lymph nodes from 2552 animals and the livers and lungs from 656 animals were collected randomly and examined. To evaluate the effect of temperature and NaCl on the survival of Linguatula spp. nymphs in infected livers and lungs, 30 g of each liver and lung with dimensions of 2 × 3 × 4 cm, were exposed to temperatures of -20, 10, 50, 60 and 72 °C and NaCl concentrations of 5 %, 10 %, 15 % and 20 % for 3, 6, 12, 24, 48 and 72 h, in triplicate. Based on the mesenteric lymph nodes, 25.7 % (656 of 2552 animals) were infected with Linguatula spp. Of the 656 liver and lungs assessed, 141 (21.5 %) and 62 (9.5 %) were infected with Linguatula spp., respectively. The rate of infection of mesenteric lymph nodes in all animals was significant with age (P < 0.05), with more older animals infected. In regards to sex, except for camels, more female animals were infected than male animals (P < 0.05). There was a significant difference in survival of nymphs based on temperature and/or NaCl and time (P < 0.0001). At 72 h, all temperatures assessed except 10 °C, resulted in all nymphs being inactivated. Sodium chloride was more effective against Linguatula spp. nymphs in livers than in lungs with 100 % efficacy only achieved against nymphs in livers at 20 % concentration after 48 h and at 10 and 15 % concentration after 72 h. Based on these results, heating and application of common salt as a food preservative in meat products reduces the survival time of Linguatula spp. nymphs and their use could decrease the risk of food-born microorganisms.

Are feral goats intermediate hosts for Linguatula (Pentastomida) in Australia?

Feral goats, Capra hircus (Bovidae), currently occur across 28% of Australia, and are found in all states and territories as well as some offshore islands. Feral goats are harvested for live export or processed as game meat, with feral goats making up approximately 90% of goats sent to slaughter in Australia. Nymphs of the pentastomid parasite, Linguatula serrata, are common parasites of goats elsewhere in the world, where they cause Halzoun or Marrara disease in humans through the consumption of nymphs in raw or semi-cooked edible offal. Despite being commonly encountered in cattle at slaughter in Australia, L. serrata nymphs have never been reported from feral goats in Australia. Goats at slaughter, however, commonly show infections of lymph nodes, the majority of which are diagnosed as caseous lymphadenitis caused by bacteria, although a small number have no known aetiology. Examination of 33 feral goats from locations in New South Wales and South Australia found a Linguatula sp. nymph encased in the mesenteric lymph node of one goat from the Cooma region of New South Wales. The potential risk of transmission of Linguatula sp. to humans and other domestic animals is discussed. This study has highlighted the importance of continued surveys of feral animals for infection with parasites, especially as their distribution changes.

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An infective nymphal Linguatula sp. was collected from the lymph nodes of a feral goat in Australia.

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This is the first report of the feral goat as an intermediate host for Linguatula in Australia.

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Linguatula poses a zoonotic risk.

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The importance of continued surveys of parasites of feral animals is highlighted.

Linguatulosis in small ruminants in southeastern Iran: Epidemiological, histopathological and phylogenetic findings and its public health importance

Linguatulosis, as a zoonotic disease, can infect most ruminants and cause accidental infections in humans. The objective of this study was to explore the epidemiological, histopathological and phylogenetic profiles of Linguatula serrata infection in sheep and goats and its public health importance during 2015-2018. Mesenteric lymph nodes (MLNs) and liver tissue of goats and sheep were selected randomly in Kerman slaughterhouse. Nymphal samples were used for DNA extraction, amplification and subsequently phylogenetic analysis using 18s rRNA and cytochrome C oxidase subunit 1 (cox1). Overall, of 828 examined livestock, 179 (42.4%) goats and 71 (17.5%) sheep were found to be infected with the nymphal stage of L. serrata. A significant difference was observed between linguatulosis and age. In the histopathological assessment, longitudinal and transverse sections of L. serrata nymphs were observed within the cyst-like spaces surrounded by a wall of fine fibrosis and compact lymphocytes. Moreover, comparing with the L. serrata reference sequences, we found only a single nucleotide change in our goat haplotype in 18s genetic region; while much nucleotide variations were observed in cox1 gene sequences. The results of the present study showed a high infection rate among goats and sheep in southeastern Iran. A better understanding of the disease could be achieved when the parasite species, their molecular characterization and the extent of infection in the area are determined. It is fundamental to select a comprehensive control program in order to take proper preventive and therapeutic measures against the infection.

Linguatula serrata in cattle in southeastern Iran: Epidemiological, histopathological and phylogenetic profile and its zoonotic importance

This study aimed to determine the prevalence, histopathological observations, and phylogenetic analysis of L. serrata in cattle and its potential zoonotic and public health implications in southeastern Iran.The cross-sectional study was performed in cattle in southeastern Iran. Lymph nodes were collected from each cattle and examined by parasitological and histopathological techniques. A binary logistic regression and chi-square tests were implemented to analyze the data. Genomic DNA was randomly extracted from the nymphal stages of Linguatula isolates. Further characterization and phylogenetic relationships were done using two primers for amplification of partial DNA fragments of 18 s rRNA and cytochrome C oxidase subunit 1 (cox1), respectively.The results showed that 64 cattle of the total 404 were infected with L. serrata. There was no significant difference between linguatulosis infection and gender, while age was significantly different (P < 0.05). The cyst-like spaces containing the longitudinal and transverse sections of the L. serrata nymphs were surrounded by granulomatous reactions. The higher nucleotide variation in the cox1 region was supported by estimating the evolutionary divergence between L. serrata isolates and other Linguatula records of ruminants in Iran. The phylogenetic tree confirmed the close evolutionary relationships among all reported records of L. serrata in Iran.The high prevalence of linguatulosis caused by L. serrata declares the existence of a potential risk of FBPs for humans in southeastern Iran. This condition can advance more serious public health problems and requires a comprehensive control program and treatment strategies to prevent the disease.

Pathological characteristics of Linguatula serrata (aberrant arthropod) infestation in sheep and factors associated with prevalence in Iran

Linguatula serrata is a cosmopolitan zoonotic parasite in which carnivores and herbivores serve as final and intermediate hosts, respectively. The aim of this study was to compare the L. serrata nymphal infection rate and intensity of infection (mean number of nymphs ± standard error) to the appearance and pathological changes of mesenteric lymph nodes (MLNs) infected with L. serrata using sheep slaughtered in Tabriz, Iran. In addition, the effect of age, sex, and season on the prevalence of L. serrata infection was evaluated. For this purpose, over a four-year period, 31,078 MLNs from 3199 sheep were examined, with 4972 (15.99%) MLNs infected representing 518 (16.20%) sheep. Collected MLNs were categorized by color as normal, red or black and by consistency as normal, soft or hard. L. serrata were found in 8.88% of normal-colored MLNs, 14.45% of red (hemorrhagic) MLNs and 44.57% of black-colored MLNs, with the difference being significant for infection and infection intensity (P < 0.0001). In regards to MLN consistency, 7.98% of normal, 31.52% of soft and 5.42% of hard lymph nodes were found to be infected with the infection rate and intensity in soft nodes being significantly different (P < 0.0001). Pathological changes in MLNs infected with L. serrata nymph with normal color and consistency had calcification of the L. serrata nymph, granulomatous inflammation around the nymph and some neutrophils. Granulomatous inflammation around the L. serrata nymph, haemosiderophage, macrophage and lymph node depletion from lymphocytes were observed in MLNs infected with L. serrata nymph with soft consistency. In addition, MLNs infected with L. serrata nymph with hard consistency and black color contained neutrophils in the capsule's wall, caseous necrotic mass and L. serrata surrounded by a thick capsule. In regards to prevalence, age, sex and season (autumn) were significant (P < 0.0001, P < 0.01, respectively). These study results suggest that targeted meat inspection and targeted animal interventions could be used to decrease human exposure to L. serrata and animal infection.

A sensitive serodiagnostic tool for the detection of active infection of zoonotic visceral and nasopharyngeal linguatulosis

Aim:

This study aimed to evaluate the different serological techniques for early diagnosis of acute concurrent infections with linguatulosis in the definitive host (dogs) and an intermediate host (goats). This evaluation compared between the gold standard (GS) test (GS; examination of nasal and fecal samples in dogs and examination of lymph nodes in goats), sandwich enzyme-linked immunosorbent assay (S-ELISA), and indirect ELISA.

Materials and Methods:

Fifty goats and fifty dogs were examined for the presence of Linguatula serrata nymphs and adults, respectively, besides the collection of blood samples from the examined animals for serologic testing.

Results:

In goats; GS, S-ELISA, and indirect ELISA showed positivity in 32 (64%), 28 (56%), and 39 (78%) samples, respectively. In dogs; GS, S-ELISA, and indirect ELISA showed positivity in 25 (50%), 25 (50%), and 30 (60%) samples, respectively. S-ELISA displayed significant higher agreement with the GS test (≥0.83) than indirect ELISA (≤0.67) in both hosts. Infection with linguatulosis showed significant relation with the age of goats and dogs and the sex of goats (p<0.05).

Conclusion:

S-ELISA displayed more sensitivity and specificity for the detection of concurrent infections with linguatulosis in both dogs and goats than indirect ELISA, which could detect the prior infections. Similarly, these assays could be used for diagnosis of concurrent infections with linguatulosis in human, especially the chronic ones.

Status of Linguatula serrata infection in livestock: A systematic review with meta-analysis in Iran

Objectives

The present systematic review attempted to determine the prevalence of Linguatula serrata (L. serrata) infection among Iranian livestock. The L. serrata known as tongue worm belongs to the phylum pentastomida and lives in upper respiratory system and nasal airways of carnivores. Herbivores and other ruminants are intermediate hosts.

Methods

MEDLINE, Embase, Web of Science, Google Scholar, and the Cochrane Library were searched from Nov 1996 to 22 Apr 2019 by searching terms including "Linguatula serrata", "linguatulosis", "pentastomida", "bovine", "cattle", "cow", "buffalo", "sheep", "ovine", "goat", "camel", "Iran", and "prevalence" alone or in combination. The search was conducted in Persian databases of Magiran, Iran doc, Barakatkns (Iran medex) and Scientific Information Database (SID) with the same keywords. After reviewing the full texts of 133 published studies, 50 studies had the eligibility criteria to enter our review.

Results

By random effects model analysis, the pooled prevalence of linguatulosis was 25% (95%CI: 18.0-33.0, I ² = 98.67 % , P < 0.001) in goats; 15.0% (95%CI: 10.0-20.0, I ² = 97.95 % , P < 0.001) in sheep; 12.0% (95%CI: 7.0-18.0, I ² = 98.05 % , P < 0.001) in cattle; 7% (95%CI: 2.0-16.0, I ² = 97.52%) in buffalos and 11.0% (95%CI: 6.0-16.0%, I ² = 96.26 % , P < 0.001) in camels. The overall prevalence in livestock was estimated to be 25%. The highest infection rate was recorded in West Azerbaijan Province (68%) and the lowest rate was in Khuzestan Province (0.23%) (P < 0.05).

Conclusions

We concluded that the high prevalence of L. serrata infection in livestock (mainly ovine linguatulosis) show the endemic status of linguatulosis in several parts of Iran and will pose a risk for inhabitants. Control strategies to reduce the parasite burden among these animals are needed.

Prevalence and associated risk factors of Linguatula serrata infection in definitive and intermediate hosts in Iran and other countries: A systematic review

Linguatula serrata is known as a cosmopolitan zoonotic parasite whose adult form inhabits the upper respiratory system, nasal airways and frontal sinuses of dogs, foxes, cats and other carnivores, which are recognized as its final hosts. Its immature form resides in mesenteric lymph nodes, liver, lungs and spleen of herbivorous and other ruminants, which serve as its intermediate hosts. Both adult and nymphal stages of L. serrata can infect humans, which typically occurs via ingestion of eggs of infected dogs or consumption of raw or undercooked infected viscera of contaminated herbivores. The most common form of infection in human is nasopharyngeal linguatulosis, also known as Halzoun syndrome or Marrara syndrome. This paper presents a review of previous studies on L. serrata conducted in Iran from 1969 to 2018 and other countries. It was found that despite the fact that many studies have been conducted in Iran, the rate of infection with this parasite has not been studied in some areas of the country. In addition, the rate of infection with L. serrata increased with the age of ruminant animals and it was significantly higher in some areas. The prevalence of L. serrata nymphal infections in most areas was higher in goats in comparison to the other animals which can be an important risk factor for human infection. Although there was no significant difference in the rate of infection among male and female animals, the prevalence of L. serrata in male animals was typically lower than females. There was no significant difference in the seasonality of nymph infection.

Linguatula serrata, a food-borne zoonotic parasite, in livestock in Bangladesh: Some pathologic and epidemiologic aspects

Food-borne parasitic zoonoses are major threats to human health and only next to the 'big three' such as AIDS, tuberculosis and malaria. Linguatula serrata is a food-borne zoonotic pentastomid that affects a wide range of animals including humans. Dogs and other carnivores are the final hosts while most herbivores, including domestic ruminants serve as intermediate hosts. Here, the study was conducted on some epidemiologic and pathologic aspects of L. serrata infection in cattle and goats through a slaughterhouse based survey. A total of 302 samples, consisting of 257 mesenteric, 26 hepatic and 19 pulmonary lymph nodes (LNs) of cattle and goats were collected. Out of 302 LNs, 136 (45.0%) were infected with the nymphal stage of L. serrata (50.7% of cattle and 31.0% of goats). Significantly, a higher (P = 0.002) rate of infection was detected in cattle. Sex, but not seasons, is a prominent determinant of the infection. The infection was mostly detected in the mesenteric LNs (MLNs) (50.9%) but the parasite was also detected in the hepatic (3.9%) and pulmonary (21.1%) LNs. Grossly, the affected LNs were enlarged, edematous and soft. Cut surface of the LNs showed spongy appearance, and sometimes nymphs were found to crawl out. Histopathological studies revealed severe damage in parenchyma of LNs, characterized by the loss of typical pattern of lymphatic follicles and trabecule. Massive infiltration with eosinophils was detected. Collectively, the data suggest that L. serrata infection is endemic in food animals and has significant pathological impacts on livestock, and people of the country are at high risk to linguatulosis.

Nasal infestation by Linguatula serrata in a dog in the UK: a case report

A two-year-old, female neutered, cross-breed dog imported from Romania was diagnosed with nasal infestation of Linguatula serrata after she sneezed out an adult female. The dog was presented with mucopurulent/sanguinous nasal discharge, marked left-sided exophthalmia, conjunctival hyperaemia and chemosis. Computed tomography and left frontal sinusotomy revealed no further evidence of adult parasites. In addition, there was no evidence of egg shedding in the nasal secretions or faeces. Clinical signs resolved within 48 hours of sinusotomy, and with systemic broad-spectrum antibiotics and non-steroidal anti-inflammatory drugs. Recommendations are given in this report regarding the management and follow-up of this important zoonotic disease.

The role of Linguatula serrata nymph in transmission of enteric bacterial pathogens to internal organs in sheep

Linguatula serrata is a worldwide zoonotic parasite belong to phylum Athropoda. When the eggs are swallowed by intermediate host, the larvae are released in intestine and reach the mesenteric lymph nodes (MLNs) and occasionally liver, lungs, heart, kidneys, spleen, and other body organs by the blood and lymph circulation. There are a few evidences showing transmission of microorganisms by migrating L. serrata. The aim of this study was to determine the role of L. serrata nymph in transmission of enteric bacterial pathogens to internal organs of sheep. For this purpose 11 parasite positive and 11 parasite negative MLNs to L. serrata were obtained from the native slaughtered sheep and were examined microbiologically in terms of bacterial contamination. The average total bacterial count and Escherichia coli count in the parasite positive samples were respectively 6.7 and 3.3 times higher than parasite negative ones (P < 0.05). However no significant differences were found for Salmonella and intestinal enterococci between parasite positive/negative samples. This indicates that L. serrata nymphs play as vehicles for bacteria and so contaminate offal. L. serrata nymphs transfer some bacterial agents to internal organs and enhance post mortem spoilage of the infected organs. It is also able to transfer some bacterial pathogens to internal organs which could potentially be the etiology of severe infectious or even zoonotic diseases. Especially in some regions where the consumption of raw or semi-cooked lymph nodes and other visceral organs are common.

The prevalence of Linguatula serrata nymphs in camels slaughtered in Mashhad slaughterhouse, Northeast, Iran

OBJECTIVE

To evaluate the prevalence of nymphal stages of L. serrata in mesenteric lymph nodes of camels slaughtered in Mashhad slaughterhouse, Northeast of Iran.

METHODS

For this purpose, mesenteric lymph nodes of 400 camels of different sex and age were examined. The lymph nodes were examined macroscopically and a digestion method was also applied for investigation of samples which was negative macroscopically.

RESULTS

The mesenteric lymph nodes of 73 camels out of 400 (18.25%) were infected by L. serrata nymphs.

CONCLUSIONS

Prevalence of L. serrata nymphs in males and females and different age was not significantly different (P>0.05), but difference was observed between the prevalence in different seasons (P< 0.05). The potential importance of these findings to human health is discussed. This is the first report of infection with L. serrate of camels in camels slaughtered at northeast of Iran.

Electrophoretic pattern of Linguatula serrata larva isolated goat mesenteric lymph node

Linguatula serrata, one of the parasitic zoonoses, inhabits the canid and felid respiratory system. The parasite is tongue-shaped, lightly convex dorsally and flattened ventrally. Males measure 1.8-2 cm, while females measure 8-13 cm in length. Disease due to infection with this parasite in humans is more likely to cause pharyngitis, nausea and vomiting, sore and itchy throat, cough, phlegm and runny nose. Present study aimed to determine linguatula's larva somatic antigens in lymph nodes of infected goats and also reveal the major component of antigenic protein. To determine the electrophoretic pattern of L. serrata's larvae, 50 samples were taken from goat's referred to the slaughter house of Amol, Mazandaran, Iran. After performing SDS-PAGE on somatic antigens, 6 bands (19, 20, 36, 48, 75,100 KDa) were seen in which the 36, 48 and 75 KDa bands were more prominent. In conclusion, it is recommended to determine the most important antigenic protein of this parasite could be used an experimental model in infection up to determine the most significant component of this parasite's antigen and use of that in immunogenicity and detection of infection.

Prevalence of Linguatula serrata nymphs in slaughtered sheeps in Isfahan province, southwest of Iran

Linguatula serrata, well known as tongue worm; is an aberrant cosmopolitan parasite, which inhabits the carnivorous mammals (especially Canidae) respiratory system. The discharged eggs infect many plant feeder animals including human that produces visceral and nasopharyngeal linguatulosis which is known as Marrara syndrome in man. In current study, the prevalence rate of infection with L. serrata nymphs in mesenteric and mediastinal lymph nodes (MLNs) of slaughtered sheeps was investigated in Esfahan Province, Iran. The MLNs of 506 slaughtered sheeps, including 236 females and 270 males, were examined for L. serrata nymphs by cutting the MLNs longitudinally and then microscopic studies for L. serrata nymphs. Sheeps were categorized into four age groups, including <1 year, 1-2 years, 2-3 years and >3 years. Results showed that 11.66 % of examined sheeps were infected with L. serrata. Age had significant effect on the prevalence rate of this parasite in sheeps (infection in sheeps with >3 years old was more than other groups significantly) and sex had no significant effect on the prevalence rate of this parasite in sheeps. Infection rate in winter was significantly lower than infection rate in spring; but there were no significant differences between the other seasons. As high prevalence rate of infection in sheeps, suggesting possibly similar high rate of infection in other animals and man in the investigated area, which this emphasizes undertaking strict control measures to reduce risk of zoonotic outbreaks. This study was demonstrated infection rate of L. serrata in sheeps in central parts of Iran.

The prevalence of Linguatula serrata nymphs in mesenteric and mediastinal lymph nodes in one-humped camels (Camelus dromedarius) slaughtered in Rafsanjan slaughterhouse, Iran

Linguatula serrata is a well-known zoonotic parasite belonging to the order of Pentastomida which infects both human and animals. Human can be infected by both the nymph stage, causing a disease condition called nasopharyngeal linguatulosis or halzoun syndrome and the egg, a condition called visceral linguatulosis. The aim of this study was to evaluate the prevalence of nymphal stages of L. serrata in mesenteric and mediastinal lymph nodes of one-humped camels slaughtered in Rafsanjan slaughterhouse, Kerman province, south-eastern Iran. For this purpose, mesenteric and mediastinal lymph nodes of 132 one-humped camels of different sex and age groups in different seasons were examined. Overall, 27 one-humped camels (20.5 %) were infected by L. serrata nymphs. The infection rate increased with age (P < 0.05). No significant difference by sex groups or seasons was observed (P > 0.05). The high prevalence of infection in one-humped camels is of major concern to public health, owing to the zoonotic nature of the parasite and the potential risk of infection to humans and other animals.

The prevalence of Linguatula serrata nymphs in goats slaughtered in Tabriz, Iran

During 1 year (April 2009-April 2010), the prevalence of Linguatula serrata (L. serrata) nymphs in liver and mesenteric and mediastinal lymph nodes (MLN) of 740 native goats of different sex and ages were examined in Tabriz, north west of Iran. Initially the organs were macroscopically examined for nymphal stage of L. serrata and then were digested by acid-pepsin method to further investigation. The prevalence rate was obtained 55.27%. The mesenteric lymph nodes (MLN) in 334 (45.13%), the lymph nodes (LN) in 102 (13.78%) and the livers in 8 (1.08%) goats out of 740 were infected with L. serrata nymphs. The results indicated a high rate of infection of LN in goats in this region of Iran.

Prevalence, biology, pathology, and public health importance of linguatulosis of camel in Iran

Linguatula serrata is a cosmopolitan zoonotic parasite with its adult form occurring in the nasal and respiratory passages of canids as the definitive hosts, while its immature stages localize in the mesenteric lymph nodes, liver, spleen, lungs, and, rarely, in other organs, such as the ocular region of herbivorous intermediate hosts. Humans can behave as both intermediate and final host and are infected by visceral and nasopharyngeal linguatulosis. Consumption of infected, improperly cooked viscera of the intermediate hosts, including sheep, goats, cattle, camels, or other herbivores containing the larval stages of this parasite is a potential source of infection of human beings with the nasopharyngeal form of linguatulosis. However, nasopharyngeal secretions or feces of carnivores containing eggs of Linguatula are the main sources for infecting human beings with the visceral form of this infection. In the present study, the prevalence of infection by nymphs of L. serrata in 101 camels in Yazd Province, central Iran, was estimated based on histopathological studies of samples from two, apparently enlarged, mesenteric lymph nodes (MLN), together with one sample from a whitish pinpoint spot on the liver and spleen of each animal. Thirteen camels (12.9%) were infected with the nymphal stage of L. serrata. Age and sex did not play a significant role in the prevalence of this parasitic infection. The number of parasites in each MLN ranged from one to six larvae. In view of the consumption of raw or undercooked liver and visceral organs of camel by humans of this region, the importance of careful inspection at slaughter needs to be emphasized.