A Total of More Than 60 Species of Spirometra have Been Reported Worldwide : A Part from the Book Chapter : Study of Spirometra Egg by Scanning Electron Microscopy: Operculum and Operculum Suture at one End

This paper presents a scanning electron micrograph taken during studies undertaken to identify the eggs of Spirometra species. Scanning electron microscopy (SEM) enables images to be obtained by detecting various signals such as secondary electrons (SEs), and backscattered electrons (BSEs) that escape from specimens when an incident electron probe emitted from an electron gun strikes the observation targets. Among these signals, both SE and  BSE signals are most commonly used in biological and biomedical research. SEs are emitted near the surface of specimens and provide surface information on tissues and cells. Spirometra is a tapeworm, belonging to the Diphyllobothriidae family, and is one of the most harmful foodborne parasites in the world. “A total of more than 60 species of Spirometra have been reported worldwide, but only four species are considered valid (S. erinaceieuropaei, S. mansonoides, S. pretoriensis, S. theileri)”. “Generally, spargana develop into adult Spirometra worms in the intestines of dogs and cats”. “After infecting humans, spargana migrate to and the brain, resulting in local tissue damage, paralysis, blindness, and even death”. “Sparganosis has a worldwide distribution and is mainly found in China, Japan, South Korea, Thailand, and Southeast Asian countries. Sporadic cases occur in South America, Europe, and Africa”. “Many infections are asymptomatic. Only severe cases are diagnosed, such as those with neurological symptoms that mainly appear as seizures, light hemiplegia, progressive headache, and disturbance of consciousness”. In China, people apply fresh snake and frog meat to wounds or abscesses to relieve skin ulcers and eye inflammation, even when swallowing raw or semi-raw frog and snake meat. Therefore, frogs and snakes become the primary source of infection. “The Spirometra tapeworm needs to live in two intermediate hosts and several paratenic hosts during the life cycle. Cyclops is the first intermediate host; snakes, frogs, birds, and many other animals are the second intermediate host; and cats and dogs are the definitive hosts”. “Sparganum develop into adults in the intestines of definitive host cats and dogs. The eggs produced by the adults are excreted in the host’s feces, and adults can be detected in the intestinal tract of the definitive host. Under the right conditions, the eggs hatch into coracidia, which, when eaten by the Cyclops, develop into procercoid larvae. When the intermediate host, the frog swallows the Cyclops containing procercoid larvae, grows to sparganum. When human, and other intermediates prey on hosts containing spargana, they become infected. When a definitive host cat or dog ingests sparganum, it develops into an adult in the intestinal tract. Therefore, this article aims to highlight the use of SEM for examining Spirometra eggs.

Author(s) Details:

Nicholas Jairo Kavana
Department of Microbiology and Parasitology, Faculty of Medicine, St. Francis University College of Health and Allied Sciences, Ifakara, Tanzania.

Also See : The Deterministic Effect Caused by High Radiation Doses : A Part from the Book Chapter : Estimation of Low Radiation Doses Effects by Using Tumor Markers

Recent Global Research Developments in Overview of Spirometra Infection

Epidemiology, Diagnosis, and Prevention of Sparganosis in Asia: This review provides comprehensive information on the life cycle, clinical characteristics, pathogenesis, and molecular diagnosis of Spirometra. It highlights the geographical distribution and infection characteristics of Spirometra in various hosts, emphasizing the importance of prevention [1] .

Sparganosis (Spirometra) in Europe in the Molecular Era: This article discusses the distribution of Spirometra in Europe, presenting the first molecular evidence of two species in the region. It reviews the current distribution and raises awareness about the parasite, which is often neglected outside Eastern Asia [2] .

Genetically Confirmed Sparganosis Case: This study reports the first genetically confirmed case of Spirometra erinaceieuropaei using the evolutionary conserved nuclear 18S rRNA gene. The sequences were identical to those found in Eurasian badger and wild boar, providing insights into the genetic identification of Spirometra species [3] .

Advances in Molecular Diagnosis of Spirometra: This research focuses on the advancements in molecular diagnostic techniques for Spirometra infection. It highlights the importance of accurate species identification through DNA sequencing to understand the origins and spread of the parasite [1] .

Global Distribution and Public Health Impact of Spirometra: This review summarizes the global distribution of Spirometra and its impact on public health. It discusses the various modes of transmission, including consumption of raw or undercooked meat and contaminated water, and emphasizes the need for public health interventions [2] .

References

1. Liu W, Gong T, Chen S, Liu Q, Zhou H, He J, Wu Y, Li F, Liu Y. Epidemiology, Diagnosis, and Prevention of Sparganosis in Asia. Animals. 2022; 12(12):1578. https://doi.org/10.3390/ani12121578
2. Roman Kuchta, Marta Kołodziej-Sobocińska, Jan Brabec, Daniel Młocicki, Rusłan Sałamatin, Tomáš Scholz, Sparganosis (Spirometra) in Europe in the Molecular Era, Clinical Infectious Diseases, Volume 72, Issue 5, 1 March 2021, Pages 882–890, https://doi.org/10.1093/cid/ciaa1036
3. Kondzior, E., Tokarska, M., Kowalczyk, R. et al. The first case of genetically confirmed sparganosis (Spirometra erinaceieuropaei) in European reptiles. Parasitol Res 117, 3659–3662 (2018). https://doi.org/10.1007/s00436-018-6079-0

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