The status of Linguatula serrata infection of stray dogs in Shiraz, Iran

Molecular characterization and phylogenetic analysis of Linguatula serrata isolated from camels, sheep and goats in Iran

Linguatula serrata is an important zoonotic parasite with worldwide distribution. The objective of the present study was to investigate the molecular characterization and phylogenetic analysis of nymphal stage of L. serrata from camels, goats and sheep in Iran. The mesenteric lymph nodes were collected from various ruminants including goats, sheep and camels at Isfahan and Shiraz slaughterhouses and the nymphs were identified using morphological characteristics. After DNA extraction, the 18 S rRNA and Cox1 genes were amplified by polymerase chain reaction. The sequencing of the genes was conducted using specific primers and a capillary DNA analyzer. The comparison of amplified sequences with existing data confirmed the presence of L. serrata with 99.6-100% nucleotide sequence similarity. Based on 18 S rRNA and Cox1 sequences, two isolates collected from sheep revealed 100% and 99.9% sequence identity, respectively. Also, three isolates from camel had 99.64-100% and 99.7-100% homology. Two isolates from sheep had 100% identity in their 18SrRNA gene and were categorized together, but showed 99.9% similarity in the Cox1 gene, not clustering together. Phylogenetic analysis of the Cox1 gene classified nearly all the isolates into L. arctica clade. It can be concluded that 18 S rRNA and Cox1 genes sequencing can be a proper method for the analysis of phylogenetic relationships of L. serrata among different hosts in different parts of Iran, possibly helpful for infection control and prevention.

The first Linguatula serrata case in an imported dog in Finland

Linguatula serrata is a pentastomid parasite infecting carnivores as definitive hosts and herbivores as intermediate hosts. In carnivores, including dogs, it usually parasitises the nasal cavity and sinuses, causing upper respiratory signs. This case report presents the first canine Linguatula case in Finland in an imported dog originating from Spain. In addition to the unremarkable clinical history of the dog, the treatment, parasite's morphology and molecular analysis are described, and the zoonotic potential is discussed.

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.

First finding of nymphal stages of Linguatula serrata in a South American camelid, a vicuña from Peru

Linguatula serrata, a pentastomid, was found parasitizing the lungs of a vicuña (Vicugna vicugna) from Cuzco, Peru. A total of 13 larvae were found encysted in the parenchymal tissue of the lungs. All larvae were identified as nymphal stages of L. serrata by morphological methods Diagnosis was confirmed by molecular analysis amplifying the cytochrome c oxidase 1 gene of three nymphs. Nucleotide sequences from the isolates were compared to previous sequences from GenBank, and it showed high similarity between them (>99%). This finding constitutes the first detection of L. serrata in a South American camelid.

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.

Linguatula serrata (Porocephalida: Linguatulidae) Infection among Client-Owned Dogs in Jalingo, North Eastern Nigeria: Prevalence and Public Health Implications

Pentastomiasis is a parasitic zoonosis endemic to western and central Africa. This study was undertaken to determine the prevalence and public health implications of Linguatulosis in client-owned dogs in Jalingo, North Eastern Nigeria. Seven hundred and seventy seven (777) dogs brought for treatment at the hospital were subjected to buccal (sublingual) examination for pentastomiasis. Parameters such as age, sex, and breeds were determined. Also, the months of the year were taken into consideration. An overall prevalence of 37.45% was recorded. Of the 477 dogs examined in 2010, 184 were positive representing prevalence of 38.57% and in 2011 107 were positive representing prevalence of 35.67%. The infection was higher in the male than in the female which does not differ significantly (P > 0.05). There was no significant difference between sexes (P > 0.05). However, significant difference (P < 0.05) was observed between breeds and age of dogs examined. Season did not have much influence on the prevalence of Linguatulosis. The high prevalence of Linguatulosis in dogs and other animals found in this study highlights the need of improving preventative measures to reduce the rate of infection, which may pose a hazard to human health.

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.