Multiple zoonotic helminth infections in domestic dogs in a rural area of Khuzestan Province in Iran

Gastrointestinal parasites of cats in the Middle East (2000-2023): A literature review

BACKGROUND/OBJECTIVE

Gastrointestinal parasites in stray cats are of significant clinical and zoonotic importance and pose a potential threat to public health. Hence, the current review has practical implications as it aims to present the diversity and the prevalence of cat parasites in Middle Eastern countries.

METHODS

The research process was rigorous and thorough, spanning from 2000 to 2023. Data collection and analysis were conducted utilizing multiple international and national databases, including Google Scholar, Scopus, PubMed, and Irandoc. This meticulous approach ensures the reliability and validity of the findings, providing a solid foundation for further research and preventive measures.

RESULTS

A total of 159 articles were collected and comprehensively reviewed. Among these, 85 articles were from Iran, 25 from Türkiye, 20 from Iraq, 11 from Egypt, five from Qatar, three from Cyprus, three from Kuwait, and one each from the UAE, Saudi Arabia, Syria, Lebanon, Jordan, Israel, and Palestine. Toxocara cati was the most prevalent nematode, exhibiting the highest prevalence in Iran, ranging from 8% to 90%, followed by Egypt, with a range of 8.23% to 58.7%. In comparison, the lowest prevalence was recorded in Qatar at 8%. Hydatigera taeniaeformis, a common cestode in the feline, showed the highest prevalence in Qatar, with a range of 73.6% to 75.8%, while the lowest was in Kuwait at 0.8%. In Iran, the prevalence ranged from 0.9% to 64.7%. Toxoplasma gondii, a cosmopolitan protozoan, showcased the highest prevalence in Lebanon at 78.1% and the lowest in the UAE at 0.8%. In Iran, the prevalence ranged between 1.2% and 90%. Additionally, noteworthy patterns regarding the distribution and potential risk factors associated with these parasites were observed. While gender variations were not significant, environmental conditions such as high humidity and absence of sunlight exposure, along with the age and behavior of cats, were among the risk factors associated with the prevalence of parasites.

CONCLUSION

The prevalence of parasites among stray cats in Iran and other Middle Eastern countries remains notably high. This emphasizes the urgent need for a series of control and preventive measures. Implementing effective anti-parasitic strategies and emphasizing the development of multiple diagnostic methods are essential.

Environmental contamination with feces of free-roaming dogs and the risk of transmission of Echinococcus and Taenia species in urban regions of southeastern Iran

BACKGROUND

Dogs are the most important definitive hosts of zoonotic taeniid helminths worldwide. Different Echinococcus and Taenia species of domestic and wild carnivores pose a potential risk to human population. High populations of free-roaming dogs (FRDs) in urban areas of Iran and widespread contamination of the environment with dog feces is a potential source of infecting people living in the urban regions with cystic echinococcosis (CE). Our knowledge on the risk of CE transmission in the urban settings in the endemic regions is limited. The present study surveyed the species and genotypes of E. granulosus sensu lato and other taeniids by examining feces of free-roaming dogs in the urban areas in the city of Kerman, southeastern Iran.

METHODS

The city was divided into 100 consecutive blocks of which 25 blocks were randomly selected. Fecal samples of FRDs were counted, mapped and fresh samples were collected. Then Zinc chloride flotation, and sequential sieving was performed, and the samples were examined under an inverted microscope. Single individual taeniid eggs were isolated, partial nad1 gene was amplified and sequenced to identify species and genotypes.

RESULTS

In total 5607 fecal samples of dogs were mapped and 83 fresh samples were collected. Taeniid eggs were detected in nine fecal samples (10.8%) from seven out of the 25 city blocks (28.0%). Echinococcus eggs were found in four samples (4.8%) from three city blocks, two samples containing E. granulosus sensu stricto (2.4%), two samples containing E. canadensis G6/7 (2.4%). In addition, three samples contained eggs of Taenia hydatigena (3.6%), and one sample of Taenia serialis (1.2%).

CONCLUSIONS

This study documented the potential risk of CE transmission to humans resulting from the feces of dogs roaming freely in urban areas.

Sparganosis in the Indian Sub-continent and the Middle East

Sparganosis is one of the common zoonotic diseases caused by infection with the larval plerocercoids (spargana) of the cestode genus Spirometra. While this parasite distributes globally in canine and feline hosts, human infection is predominantly reported in East Asia, especially China, Korea, Japan, and Thailand. Maybe related to the behavior and food culture, this zoonotic disease is rather rare in South Asia to the Middle East. In these areas, sporadic case reports have been appeared mostly in the local medical journals. To draw a solid picture of sparganosis in these non-endemic areas of Asia, we made an extensive literature survey to gather sparganosis cases in the Indian subcontinent and the Middle East.

Cardiac hydatid disease; a systematic review

BACKGROUND AND OBJECTIVES

Human cystic echinococcosis (CE), is a common health problem in low- and middle-income countries. Cardiac involvement is a relatively rare manifestation of Echinococcus infection. This study aims to summarize the evidence regarding the features of cardiac CE.

METHODS

Case series of the patients with cardiac CE, were included in this study. Non-English papers, case reports, reviews, letters, , commentaries, and conference abstracts were not included. A systematic search was conducted in PubMed and EMBASE databases and the risk of bias in the included studies was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist.

RESULTS

Out of 3985 results of the searches, finally 37 studies were included in this systematic review. Based on available evidence, cardiac involvement is an uncommon but serious presentation of CE which presents with some non-specific signs and symptoms. Dyspnea, chest pain, and palpitation are the most common symptoms of the disease and normal sinus rhythm is the most common Electrocardiogram (ECG) feature. The disease is not associated with high mortality in case of timely diagnosis and appropriate management.

DISCUSSION

Consecutive and complete inclusion of participants, statistical analysis, and appropriate reporting of the demographics were the sources of bias in the included studies. The exclusion of non-English papers was a limitation during the review process.

FUNDING

The research protocol was approved and supported by the Student Research Committee, Tabriz University of Medical Sciences (grant number: 69380).

REGISTRATION

This study was registered in the International prospective register of systematic reviews (PROSPERO ID: CRD42022381204).

Molecular characterization of Cysticercus tenuicollis isolates from sheep in the Nile Delta, Egypt and a review on Taenia hydatigena infections worldwide

The predator–prey-transmitted cestode Taenia hydatigena infects a wide range of definitive and intermediate hosts all over the world. Domestic and sylvatic cycles of transmission are considered as well. The parasite has considerable economic importance, particularly in sheep. Here, the molecular characters of T. hydatigena cysticerci in sheep from the Nile Delta, Egypt were investigated for the first time. For this purpose, 200 sheep carcasses and their offal were inspected at the municipal abattoir, Dakahlia governorate, Egypt. Cysticerci of T. hydatigena were collected and molecularly characterized employing the mitochondrial 12S rRNA gene. Cysticerci were found in 42 (21%) sheep, mostly attached to the omenti, mesenteries and livers. After molecular confirmation, nine isolates were sequenced displaying six different haplotypes. Analysis of the T. hydatigena 12S rRNA nucleotide sequences deposited in GenBank revealed 55 haplotypes out of 69 isolates, displaying high haplotype (0.797) and low nucleotide (0.00739) diversities. For the Tajima D neutrality index, a negative value (−2.702) was determined, indicating the population expansion of the parasite. Additionally, global data summarized in this study should be useful to set up effective control strategies against this ubiquitous parasite.

Echinococcoses in Iran, Turkey, and Pakistan: Old Diseases in the New Millennium

Echinococcosis is considered a cosmopolitan zoonosis caused by different species of small taeniid tapeworms of the genus Echinococcus and is regarded as a neglected zoonosis. Cystic and alveolar echinococcoses are endemic diseases of Tibetan, Pamir, and Iranian plateaus. All of the countries within the Iranian plateau are affected by echinococcosis. Pakistan, Turkey, and Iran are the three most populous countries of the region, in which echinococcosis is highly endemic. The three neighboring countries share strong cultural and socioeconomic ties. The present study aimed to provide a broad review of the status of cystic and alveolar echinococcosis, summarizing the current knowledge about geographical distribution, molecular epidemiology, and transmission dynamics of Echinococcus granulosus sensu lato and Echinococcus multilocularis in this region. Additionally, we aimed to understand disease burden and risk factors as basic requirements for establishing a surveillance system and planning prevention and control programs. A considerable body of information is available on different aspects of echinococcosis in this region; however, several information and research gaps need to be filled before planning control programs. None of the countries in the region have an elaborate echinococcosis control program. Effective control programs require multi/intersectoral coordination within a One Health approach with a long-term political and administrative commitment and enhanced international collaboration among the three countries.

A global assessment of Echinococcus multilocularis infections in domestic dogs: proposing a framework to overcome past methodological heterogeneity

Echinococcus multilocularis, the aetiological agent of human Alveolar Echinococcosis, is transmitted between small mammals and wild or domestic canids. Dogs infected with E. multilocularis as dead-end hosts. Whereas E. multilocularis infections in wild hosts and humans have been well-studied in recent decades, infections in domestic dogs are sparsely reported. This literature review and meta-analysis highlighted gaps in the available data and provided a re-assessment of the global distribution of domestic dog E. multilocularis infections. We found 46 published articles documenting the prevalence of E. multilocularis in domestic dogs from 21 countries across Europe, Asia and North America. Apparent prevalence estimates ranged from 0.00% (0.00-0.33%) in Germany to 55.50% (26.67-81.12%) in China. Most studies were conducted in areas of high human Alveolar Echinococcosis. By accounting for reassessed diagnostic sensitivity and specificity, we estimated true prevalence in a subset of studies, which varied between 0.00% (0.00-12.42%) and 41.09% (21.12-65.81%), as these true prevalence estimates were seldom reported in the articles themselves. Articles also showed a heavy emphasis on rural dogs, dismissing urban ones, which is concerning due to the role urbanisation plays in the transmission of zoonotic diseases, especially those utilising pets as definitive hosts. Lastly, population studies on canine Alveolar Echinococcosis were absent, highlighting the relative focus on human rather than animal health. We thus developed a framework for investigating domestic dog E. multilocularis infections and performing risk assessment of dog-associated transmission to fill the gaps found in the literature.

Infection rate and biochemical characterization of Cysticercus tenuicollis from sheep in Minoufiya governorate, Egypt

Cysticercus tenuicollis, the larval stage of Taenia hydatigenia, infects sheep and causes economic losses due to condemnation of infected organs. This study was designed to report the infection rate, risk factors, biochemical, and molecular characterization of Cysticercus tenuicollis in sheep from Ashmoun, Minoufiya, Egypt. The infection rate was 18%. The age was a risk factor for infection where there was a significant difference in infection rate between sheep more than 3 years and sheep under 3 years of age. There was no significant difference between infection in male and female groups. The liver had the highest organ distribution followed by omentum. Biochemical analysis of the cyst fluid showed some variations in the levels of ALT, AST, triglycerides, cholesterol, total protein, urea nitrogen, calcium, sodium, chromium, potassium than the levels identified in Algeria, Iraq, and Iran. PCR and sequence analysis of cox1 and ssrRNA showed that the sequences from Minoufiya, Egypt were highly identical to the related ones from several countries and confirmed the cyst is Cysticercus tenuicollis. This study reported the infection rate, risk factors, biochemical analysis, and molecular characterization of Cysticercus tenuicollis in sheep from Minoufiya, Egypt.

Prevalence of Intestinal Helminth Infections of Stray Dogs of Public Health Significance in Lagos Metropolis, Nigeria

Globally, stray dogs have been a major source of zoonoses such as cutaneous larval migrans, visceral larval migrans and hydatidosis. These dogs are recognized as being a major public health problem where their population is unchecked. This study was conducted to determine the prevalence of intestinal helminth parasites of stray dogs in Lagos metropolis. Stools of 96 stray dogs were examined microscopically for ova of these parasites using centrifugation flotation method. Four species of intestinal helminths were identified. The overall prevalence of helminths infection was 61.4%, with Ancylostoma caninum having a prevalence of 62.5%, Toxocara canis 20.8%, Dipylidium caninum 18.7% and Strongyloides stercoralis 2.0%. T. canis had the highest worm burden of 1,250 egg per gram (EPG) while S. stercoralis had the least (100 EPG). The areas with the most helminth infections were Yaba (n=12, X̄=1.58, SD=0.793), Agege (n=11, X̄=1.73, SD=0.786) and Ikotun (n=11, X̄=1.45, SD=0.820). S. stercoralis was only found in samples obtained from Mushin and Ikorodu. Most of the stool samples obtained from this study had mixed infections, 83.3% were infected with three helminth species, 8.3% were infected with four helminth species and none had double infection. Mushin had the most mixed infections (n=4, X̄=1.900, SD=1.101) while Obalende had the least (n=1, X̄=1.000, SD=0.000). Most of the intestinal helminth parasites identified in this study are zoonotic and thus pose a public health problem. Environmental factors seem to influence the health condition of these dogs, thus concerted efforts should be made to reduce the growing population of stray dogs on the street of Lagos.

The Relation between Toxocariasis and Toxoplasmosis co-infection and the presence of Rheumatoid Factor (RF) in people with hydatidosis in Southwestern Iran, from 2013 to 2018

Toxoplasmosis, toxocariasis, and hydatidosis are parasite diseases with a very human-like pathway of infection. worldwide including Iran, there are infected people with these infections. Between 2013 and 2018, serum samples were collected from 124 patients with hydatidosis and 124 serums from hydatidiosis free. Samples were examined for the presence of toxocariasis by detecting IgG antibodies, using the ELISA (Enzyme-Linked Immunosorbent Assay) IBL kit and for the presence of IgG antibodies for toxoplasmosis, using the ELISA test. Risk factors such as contact with animal pets; cats and dogs, rural or urban living, age, sex, and Presence of rheumatoid factor (RF) in serum were investigated during the study. The presence of RF was examined using an agglutination test in all confirmed cases of hydatidosis, toxocariasis, and toxoplasmosis. Of the 124 positive cases of hydatidosis, 30 (24.2%), 51 (41.1%) and 15 (12.09%) had toxoplasmosis, toxocariasis and simultaneous infection (toxoplasmosis and toxocariasis), respectively. In people with toxocariasis, rheumatoid factor was reported more frequently than in other cases. The relationship between the prevalence of rheumatoid factor in serum in people with toxocariasis was significant (41.18%). Interaction with dogs and cats and area of residence were identified as risk factors for toxocariasis (P value > 0.005). Although hydatidosis and toxocariasis are Less common infections compare with toxoplasmosis, they are considered a threat to public health in some parts of the world, including Iran. Some factors, such as habitat and interaction with animal pets (dogs and cats), play a more significant role in toxocariasis compared to toxoplasmosis in people with hydatidosis.