Parasitic Infections and Host Tissue Response in Histopathology: A Rare Retrospective Research Study from Rural India.

OBJECTIVE: Parasite are living organisms which survive on another living being for their nourishment and survival. When these parasites resides on human body, they bring about inflammatory response. This inflammatory response leads to tissue reaction. Tissue response on microscopy appear as an eosinophilia, abscess and granulomas. This study was planned with the objective to know the frequency of parasite infection, tissue response in parasite infection and its comparison in terms of variables like age, sex and the type of parasite. METHODS: This is a retrospective study, conducted in the department of pathology. A total of 26 cases of parasitic infections in human specimens reported in our department from January 2008 to December 2019 were included in this study. On all archived cases hematoxylin and eosin and where ever required periodic acid schiff was applied. These slides were thoroughly examined and clinicopathological correlation was studied. RESULTS: Age range of patients was 5 years to 70 years. Maximum number of patients were belonging to 11-20 year age group. Male to female ratio was 1:2. Among the 26 cases, there were 9 cases (34.62%) of hydatid cyst, six cases of Entamoeba histolytica (23.07%), four cases of Enterobious vermicularis (15.38%), and two cases (7.69%) each of Ascaris lumbricoides, filaria and cysticercosis respectively. A specific tissue response seen in cysticercosis having chronic inflammatory cells, palisaded epithelioid cells granuloma and giant cell reaction while other showed inflammatory cells infiltration. CONCLUSION: Clinically diagnosis of parasitic infection in each and every case is not possible, similarly radiological investigation is also suggestive only. Histopathology examination is the benchmark investigation to diagnose parasite infection and tissue reaction to the host. Histopathology examination must be implicated in every case to identify parasite and tissue reaction so that the patients can be managed accordingly before the complications rises.

[Prevalence of Enterobius vermicularis infections among children in China from 2016 to 2021: a meta-analysis].

OBJECTIVE: To investigate the prevalence of Enterobius vermicularis infections among children in China from 2016 to 2021, so as to provide insights into enterobiasis control and formulation of the enterobiasis control strategy among children. METHODS: Publications pertaining to the prevalence of E. vermicularis infections among children were retrieved from Wanfang Data, CNKI, VIP and PubMed databases published from January 2016 to June 2023. Eligible publications were screened according to inclusion and exclusion criteria, and the publication bias was evaluated using the assessment tool for prevalence studies proposed by the Joanna Briggs Institute Evidence-Based Practice Resources in Australia. The study period, study areas, study subjects, sample size and number of infections were extracted from publications, and a pooled analysis was performed using a meta-analysis. A meta-regression analysis was performed with the prevalence of E. vermicularis infections as an independent variable, and sample size, source of samples, study area, study method, geographical area and province as dependent variables to identify the source of the study heterogeneity. RESULTS: A total of 66 studies were included, covering 23 provinces (municipalities, autonomous regions) in China, and with the investigations conducted between 2016 and 2021. Meta-analysis showed that the pooled prevalence of E. vermicularis infections was 4.5% [95% confidence interval (CI): (3.1%, 6.0%)] among children in China from 2016 to 2021, and the annual prevalence was 4.1% [95% CI: (2.2%, 6.5%)], 4.2% [95% CI: (2.4%, 6.6%)], 4.2% [95% CI: (2.2%, 6.8%)], 3.2% [95% CI: (1.5%, 5.4%)], 2.3% [95% CI: (0.9%, 4.3%)] and 1.1% [95% CI: (0.4%, 2.1%)] from 2016 to 2021. The pooled prevalence of E. vermicularis infections was 4.9% [95% CI: (3.4%, 6.8%)] in studies with a sample size of < 5 000 cases, which was higher than that in studies with a sample size of 5 000 cases and higher [2.1%, 95% CI: (0.2%, 3.6%)], and the pooled prevalence of E. vermicularis infections was 5.2% [95% CI: (2.9%, 8.2%)] among subjects from schools, which was higher than that among subjects from communities [4.2%, 95% CI: (2.7%, 6.0%)]. The pooled prevalence of E. vermicularis infections was 4.4% [95% CI: (2.8%, 6.2%)] among children included in comprehensive surveillance, which was higher than that among children included in specific surveillance [4.8%, 95% CI: (2.6%, 7.7%)], and the pooled prevalence of E. vermicularis infections was 5.7% [95% CI: (3.8%, 7.8%)] among children included in county-level surveys, which was higher than that among children included in city-[4.8%, 95% CI: (2.3%, 8.0%)] and province-level surveys [1.8%, 95% CI: (0.3%, 4.7%)]. In addition, the pooled prevalence of E. vermicularis infections was higher among children in southern China [11.3%, 95% CI: (7.5%, 15.7%)] than that in central China [5.2%, 95% CI: (2.8%, 8.2%)], eastern China [5.2%, 95% CI: (2.8%, 8.2%)] and southwestern China [2.6%, 95% CI: (1.4%, 4.1%)]. Meta-regression analysis identified geographical area and survey province as factors affecting the study heterogeneity. CONCLUSIONS: Currently, the overall prevalence of E. vermicularis infections is moderate among children in China, and the prevalence varies greatly in regions, with a high prevalence rate in southern China and presence of small-scale clusters. Enterobiasis surveillance and health education pertaining to enterobiasis control are required with adaptations to local circumstance to reduce the prevalence of E. vermicularis infections among children.

Genotype Distribution of Enterobius vermicularis Isolates from Northwest Provinces of Iran.

Background: Human infection with Enterobius vermicularis occurs worldwide. The most common clinical manifestation of a pinworm infection is an itchy anal region. This parasite is incidentally found in appendicitis. This study aims to characterize and genotype this parasite from different samples inferred by mt-DNA. Methods: Forty appendectomies for acute clinical appendicitis, 40 positive scotch-tape samples, and 10 adult females worm isolated from patients. Genetic differentiation, haplotype differences, and isolates population structure were analyzed based on the cytochrome c oxidase subunit I (cox1) gene. Results: It has been demonstrated that all isolations in the appendectomies specimens are similar, and the genetic difference divergence is seen in adult worm specimens. The neutral indices of the samples did not show a significant difference and show that there is no intra-specific and population distribution diversity. Conclusion: Our results show different haplotypes in the B type of E. vermicularis population and add new information about genotyping of these parasites in Iran. In comparison with other studies, intra-specific variation of this parasite from Iran was observed.

Seeds or Parasites? Clinical and Histopathological Features of Seeds and Parasites in the Appendix.

OBJECTIVE: Parasites and plant seeds may both be found in appendectomy specimens. Each plant seed has a different appearance and can thus exhibit wide variations under the microscope. Fragmented seeds may histologically mimic parasites. The differential diagnosis between seeds and parasites can be challenging in such cases. This study aimed to determine the incidence of parasites, seeds, and foreign bodies in appendectomy materials and highlight the most characteristic histopathological features associated with these structures. MATERIAL AND METHOD: In this study, pathology slides of 9,480 patients, who underwent appendectomy between 2010 and 2021, were reviewed, and cases that contained parasites, seeds, or foreign bodies were identified. We reviewed the literature on seeds and parasites in appendectomy specimens. RESULTS: Parasites were observed in 56 (0.6%) cases. Of these cases, 45 had Enterobius vermicularis (80%), and 11 had Taenia subspecies (20%). Plant seeds were observed in 47 cases (0.5%), and were macroscopically recognizable in 5 of them as olive, lemon, and cherry seeds. Parasites and seeds were usually observed in the lumen of appendix vermiformis, filled with abundant fecal materials. CONCLUSION: Seeds are seen in approximately 0.5% of the appendectomy specimens. Though rarely seen, the fragmented seed appearance may cause diagnostic difficulties. In this context, the key morphological features of parasites and plant seeds outlined in this study may be helpful in their differential diagnosis.

Molecular and phylogenetic analysis of E. vermicularis in appendectomy specimens from Iran.

Human infection with Enterobius vermicularis occurs worldwide, particularly in children. The role of E. vermicularis in appendicitis is neglected. This study was designed to investigate genotypes of E. vermicularis detected from appendectomy specimens in the human population from Iran and clarify the intra-species variation of the parasite. Seventy appendectomies for acute clinical appendicitis isolates from Azerbaijan and North Khorasan of Iran were used in the present study. The genetic information of Tehran and Hamedan regions was also obtained from GenBank for comparison and analysis. The nucleotide sequence of cytochrome c oxidase subunit 1 (cox1) gene was analyzed to perform genetic differentiation, haplotype network analysis, and population structure. Phylogenetic analysis of all the isolates were included in type B haplogroup. The number of haplotypes in all geographical locations of Iran is not much. Network analysis of sequences for regions such as Thailand, Iran, Denmark, and Poland show three classified subtypes B1, B2, and B3 in the B haplogroup. It seems that the haplotypes of E. vermicularis detected from appendectomy are B type, and divided into three subtypes. Further research using another genetic marker is required to elucidate the genetic variation of the parasites in detail.

A "fruitful" cause of acute appendicitis.

INTRODUCTION: Acute appendicitis is a common health problem mainly due to a lumen obstruction. The obstruction is mainly due to fecal material, lymphoid hyperplasia or parasites. Foreign bodies and especially seeds have been rarely reported as causes of acute appendicitis and account for less than 1% of the different causes. CASE REPORT: The authors described a rare case of acute appendicitis caused by seed and causing diagnostic challenge with the most frequent parasites observed in the appendix lumen. Different arguments were gathered to rule out enterobius vermicularis, taenia species, ascaris infection or schistosomiasis. CONCLUSION: Seed-caused-appendicitis has to be known and identified by pathologists in order to avoid the diagnosis of parasites infection which may induce an overuse of antibiotics after the appendectomy.

Prevalence and genetic analysis of Enterobius vermicularis in schoolchildren in lower northern Thailand.

Enterobius vermicularis, a nematode parasite with a global distribution causes enterobiasis in schoolchildren and is considered a neglected parasite. An understanding of the prevalence and genetic diversity of enterobiasis is crucial for appropriate control measures. Therefore, the objectives of this research were to study the prevalence and genetic diversity of E. vermicularis in schoolchildren from lower northern Thailand, based on cytochrome c oxidase subunit I (COI) and internal transcribed spacer 2 (ITS2) sequences. Using the scotch tape technique, 7.4% (188/2544) of schoolchildren from 21 primary schools were found positive for E. vermicularis eggs, which is a relatively low infection rate. Phylogenetic trees of partial COI sequences (397 bp) revealed similar topologies using maximum likelihood (ML) and neighbor-joining (NJ) methods and identified E. vermicularis type A (105 sequences) and B (1 sequence). Haplotype network analysis of the COI sequences demonstrated a high haplotype diversity (Hd = 0.9028). In contrast, phylogenetic analysts of a 343 bp region of the ITS2 locus (52 sequences) revealed a monophyletic group. More sequence analyses of E. vermicularis from humans and other hosts in Thailand are necessary to better understand the genetic diversity of this parasite.

Characterization of antigens of Enterobius vermicularis (pinworm) eggs.

Enterobiasis (pinworm infection) caused by Enterobius vermicularis is a common parasitic infection prevalent worldwide especially in children. Infection is diagnosed by microscopic detection of E. vermicularis eggs on perianal swabs. This study aimed to characterize the antigens of E. vermicularis eggs as a preliminary step towards identifying diagnostic targets for detection in infected individuals. The study was conducted between October 2019 and February 2020, following approval from Ethics Review Committee of the Faculty of Medicine, University of Colombo (EC-19-034). E. vermicularis eggs were harvested from perianal swabs using acetone and purified with 1× PBS (pH 7.2). A portion of eggs was used for preparing antigen slides, while the rest were sonicated and vortexed with glass beads and inoculated subcutaneously (with weekly booster doses) into a Wistar rat for developing antibodies. Blood drawing from rat was done weekly for 5 weeks. Confirmation of the presence of antibodies was done by surface immunofluorescence against eggs on the antigen slides. Protein bands were determined using SDS-PAGE assay and immunogenic antigen bands were determined by reacting with antiserum after immunoblotting. The band sizes of the proteins were determined against corresponding bands of a protein ladder. Surface immunofluorescence was positive with serum obtained from day 14 post-inoculation from the Wistar rat as well as that obtained from a person with chronic enterobiasis. The most prominent and immunogenic protein bands identified from egg antigens were 21 kDa, 66 kDa, 83 kDa, 96 kDa, 112 kDa, 121 kDa, 140 kDa and 151 kDa. Methods used in this study were effective in obtaining E. vermicularis egg antigens which were immunogenic. Furthermore, surface antigens of intact eggs reacted with antibodies developed against crushed egg antigens. These findings may pave the way for the development of effective immunodiagnostics.

Intramural Ova of Enterobius vermicularis in the Appendix-An Egg-Topic Location!

We report an unusual case of appendicitis in a 9-year-old girl in whom the wall of the appendix contained necrotizing granulomas, as well as eggs of Enterobius vermicularis. Although luminal E vermicularis adult parasites are commonly identified in the appendix and luminal eggs are occasionally seen, intramural worms and eggs are rare. We are unaware of earlier reports of ectopic intramural eggs in the appendix. It is important to and make a correct diagnosis, as both, the patient, as well as the family should be treated for enterobiasis.

Pinworm infection in school children of four districts of Malakand region, Khyber Pakhtunkhwa, Pakistan / Infecção por Pinworm em crianças em idade escolar de quatro distritos da região de Malakand, Khyber Pakhtunkhwa, Paquistão

Illnesses caused by human pinworm remains a pediatric health problem in developing nations including Pakistan. This study aimed to investigate the prevalence of Enterobius vermicularis in school children of four districts in Malakand region, Pakistan. Four hundred faecal specimens were screened from May 2014 to July 2017 using normal saline and Lugol Iodine solution. Twenty three (5.75%) individuals were found infected with E. vermicularis. Five children (1.25%) were infected with only E. vermicularis and eighteen (4.5%) were mixed with other helminths. E. vermicularis 23 (5.75%), hookworm 11 (2.75%), Ascaris lumbricoides 5 (1.25%), Taenia saginata 2 (0.5%) and Trichuris trichuira 4 (1%) were detected. Age wise 5-8 years were more parasitized followed by 13-15 and 9-12 years of age (0.0296, P<0.05). Male children were highly (0.06700, P<0.05) infected than female. Children in Malakand district were found more infected followed by Dir Upper, similar infection rate was noted in children of districts Lower Dir and Swat (0.0192, P<0.05). Children in primary level were highly (0.0013, P<0.05) infected than those of middle and high levels. Enterobiosis is still the most common parasitic diseases in children. Studies on enterobiosis should be conducted time by time to recognize the hazardous of such parasitic infection in remote areas of the country.

As doenças causadas pela traça humana continuam sendo um problema de saúde pediátrica nos países em desenvolvimento, incluindo o Paquistão. Este estudo teve como objetivo investigar a prevalência de Enterobius vermicularis em escolares de quatro distritos na região de Malakand, Paquistão. Quatrocentos espécimes fecais foram selecionados de maio de 2014 a julho de 2017, usando solução salina normal e solução de lugol iodo. Vinte e três (5,75%) indivíduos foram encontrados infectados por E. vermicularis. Cinco crianças (1,25%) foram infectadas apenas com E. vermicularis e dezoito (4,5%) foram misturadas com outros helmintos. Foram detectados E. vermicularis 23 (5,75%), ancilóstomo 11 (2,75%), Ascaris lumbricoides 5 (1,25%), Taenia saginata 2 (0,5%) e Trichuris trichuira 4 (1%). Com relação à idade, 5-8 anos foram mais parasitados, seguidos por 13-15 e 9-12 anos de idade (0,0296, P <0,05). Crianças do sexo masculino foram altamente (0,06700, P <0,05) infectadas do que as do sexo feminino. As crianças no distrito de Malakand foram encontradas mais infectadas, seguidas por Dir Upper, taxa de infecção semelhante foi observada em crianças dos distritos Lower Dir e Swat (0,0192, P <0,05). As crianças do nível primário foram altamente (0,0013, P <0,05) infectadas do que as dos níveis médio e alto. A enterobiose ainda é a doença parasitária mais comum em crianças. Os estudos sobre enterobiose devem ser conduzidos periodicamente para reconhecer a periculosidade dessa infecção parasitária em áreas remotas do país.

Parasitic Appendicitis in 14.797 Cases: A Retrospective Cohort Study

Objective: This study aimed to determine the frequency of Enterobius vermicularis in appendectomy specimens and evaluate the histopathological characteristics of adult and pediatric cases with E. vermicularis infection. Methods: Appendectomies examined from 1 January 2010, to 1 December 2020, were analysed retrospectively. Cases were divided into two groups: under 18 years (children) and 18 and over (adults). Demographic and histopathological characteristics of patients were also examined. Results: Out of 14.797 patients that underwent appendectomy, 6.130 were children and 8.667 were adults. E. vermicularis was detected in 268 patients, wherein 64.2% were children and 35.8% were adults. In the detection of E. vermicularis in appendectomy specimens, the frequency was higher in children compared to that in adults (2.85%, 1.1%, respectively) (p<0.001). Histopathologically, acute appendicitis was defined in 31.7% (n=85) of 268 cases, and E. vermicularis was found to cause a higher rate of acute appendicitis in adults (p<0.001). Conclusion: The frequency of E. vermicularis in appendectomy specimens is higher in children. However, E. vermicularis causes acute appendicitis more frequently in adults.

[Enterobius vermicularis infection in Guiyang City, Guizhou Province: a case report].

The report presents a case with Enterobius vermicularis infections in Guiyang City, Guizhou Province, aiming to strengthen the attention to parasitic infections.

Morphological and molecular characterization of Aspiculuris tetraptera (nematoda: Heteroxynematidae) from Mus musculus (rodentia: Muridae) in Saudi Arabia.

Aspiculuris tetraptera a pinworm of mice, is an important parasite in institutions with mice colonies for both research and teaching purposes. Infection with this parasite has impact on biomedical research. This is likely due to the availability of the parasite's eggs in the environment, therefore can easily be transmitted and infection is generally asymptomatic. No information regarding the prevalence, morphology or phylogeny is available on A. tetraptera from Saudi Arabia. A group of 50 laboratory mice were investigated for the presence of A. tetraptera. Worms were described morphologically and molecular characterization was attempted using 18S rRNA and Cytochrome Oxidase Subunit I genes. The prevalence of A. tetraptera infestation in the laboratory mice examined was found to be 46%. Morphological description indicated that the worms belong to A. tetraptera and this was confirmed by molecular characterization. Both regions studied have shown that the worm under investigation grouped with A. tetraptera. 18S rDNA sequences obtained in the present study showed high identity with sequences from A. tetraptera while Cytochrome c Oxidase subunit I gene (COI) sequences showed intraspecific variation resulted into two haplotypes from the isolates in the present study. A. tetraptera was recorded for the first time from Saudi Arabia. Molecular characterization has shown, based on the COI sequences, that the Saudi isolates of A. tetraptera are distinct.

First report in pre-Columbian mummies from Bolivia of Enterobius vermicularis infection and capillariid eggs: A contribution to Paleoparasitology studies.

OBJECTIVE: This study was designed to search for ancient parasites in abdominal content and coprolites from Bolivian mummies. MATERIALS: Twelve mummified individuals from the Andean highlands, housed at the National Museum of Archaeology (MUNARQ) in La Paz, Bolivia. METHODS: Microscopic analysis of rehydrated samples (coprolites and abdominal content), following Lutz's spontaneous sedimentation technique. RESULTS: Eggs of Enterobius vermicularis were identified in coprolites from one mummy, and capillariid eggs in the organic abdominal content from another individual. CONCLUSIONS: This is the first evidence of ancient intestinal parasites in Bolivian mummies. SIGNIFICANCE: This pioneering study focused on the search of ancient intestinal parasites in human remains of the Bolivian Andes and contributes to greater knowledge of paleoparasitology in South America. LIMITATIONS: All mummies in the MUNARQ belonged to the Andean Bolivian highlands (post-Tiwanaku era or Late Intermediate Period), although the exact provenance of the material and the associated contexts are not well recorded. SUGGESTIONS FOR FURTHER RESEARCH: Considering the great number of well-known archaeological sites and other unexplored sites in Bolivia, in addition to large collections in museums, further paleopathological and paleoparasitological molecular studies in mummies and skeletons are called for.

The Distribution of Intestinal Parasites in Patients Presenting to a University Hospital in Istanbul: A Seven-year Retrospective Analysis

Objective: The purpose of this study was to determine the intestinal parasite distributions in patients who applied to the Parasitology Laboratory of Istanbul University-Cerrahpasa, Cerrahpasa Medical Faculty, by evaluating the parasites retrospectively. Methods: Normal saline and stool lugol were applied for direct examination of stool samples that were sent for parasite examination; cellophane band samples were evaluated microscopically. The samples suspected to have protozoa were evaluated using modified acid fast and trichrome staining methods. We evaluated the parasitological examination results of patients who applied to our laboratory between January 2012 and December 2018. Results: A total of 2.96% of the 20,948 patients who applied had parasites in their faeces. Blastocystis spp. was detected at the highest rate (63.23%), followed by Giardia intestinalis (17.26%), Enterobius vermicularis (12.58%), Taenia saginata (2.42%), Cryptosporidium spp. (1.94%) and Entamoeba histolytica/dispar (1.45%). Conclusion: Although the prevalence of intestinal parasitic infections has decreased when compared to previous years, it still remains important. For this reason, solving infrastructure problems, providing information on personal hygiene and sanitation rules are among the most important tasks needed to reduce the prevalence of intestinal parasites.

Effects of anthelmintics on the pinworm Blatticola blattae in laboratory-reared German cockroaches Blattella germanica.

The efficacy of pyrantel pamoate, pyrvinium pamoate, ivermectin, and piperazine citrate against pinworm in cockroach was evaluated. Laboratory-reared German cockroaches naturally infected with Blatticola blattae were treated with the anthelmintics and necropsied at 3 to 35 days after treatment. Ivermectin at over 5 ppm and piperazine citrate at over 2000 ppm killed all the treated cockroaches. Pinworms were still detected in cockroaches given lower concentration of the aforementioned drugs. Administration of pyrantel pamoate (100-1000 ppm) and pyrvinium pamoate (2000 ppm) did not kill the cockroaches, and no pinworms were detected at 3 and 17 days after treatment. Thus, pyrantel pamoate and pyrvinium pamoate were found to be effective for deworming B. blattae in the German cockroaches, without causing mortality for the host. Our results showed that anthelmintics selection is essential for eradication of pinworms in cockroaches because of the toxicity for the host such as ivermectin or piperazine citrate. This is the first report of piperazine citrate toxicity in cockroaches.

Perforation of the Small Intestine with Acute Peritonitis Caused by Enterobius Vermicularis.

Perianal and perineal pruritus is often associated with Enterobius vermicularis in children. Although this roundworm is common in pediatric practice, most doctors are unaware that it can cause appendicular colic with/or appendicitis, severe urogenital complications, bowel perforation, and peritonitis. We report a case of a young male who presented with signs and symptoms of acute peritonitis. Dur-ing the operation, perforation of the jejunum with a purulent exudate under the transverse colon, a left lateral canal, a Douglas cavity were found as well as single enlarged mesenteric lymph nodes. Histological studies detected Enterobius vermicularis in the lumen of the appendix and jejunum, as well as in the purulent exudate in the intestinal wall and serosa. A mesenteric lymph node, histologically presented with chronic nonspecific lymphadenitis. In conclusion, infection with Enterobius vermicularis should be considered in peri-tonitis, appendicitis, and enlarged mesenteric lymph nodes, especially in young patients.