Amebiasis presenting as acute appendicitis: Report of a case and review of Japanese literature

Amebiasis as a sexually transmitted infection: A re-emerging health problem in developed countries

Amebiasis, which is caused by Entamoeba histolytica (E. histolytica), is the second leading cause of parasite-related death worldwide. It manifests from asymptomatic carriers to severe clinical conditions, like colitis and liver abscesses. Amebiasis is commonly seen in developing countries, where water and food are easily contaminated by feces because of the poor sanitation. However, a recently challenge in many developed countries is the increase in domestic cases of invasive amebiasis as a sexually transmitted infection (STI amebiasis). In contrast to food-/ waterborne transmission of E. histolytica in developing countries, transmission of STI amebiasis occurs directly through human-to-human sexual contact (e.g., men who have sex with men and people who engage in oral-anal sex); in this setting, asymptomatic infected individuals are the main reservoir of E. histolytica. The Development of screening methods for the early diagnosis of asymptomatic E. histolytica infection is the key to epidemiologic control. Moreover, delay in diagnosis of severe cases (e.g., fulminant amebiasis) leads to death even in developed countries. It is also important to increase clinical awareness of domestically transmitted STI amebiasis in the clinical settings. This review considers the changing epidemiology and clinical manifestations of STI amebiasis, and finally discusses the future strategies for the better practice.

Acute appendicitis secondary to Entamoeba histolytica infestation

Acute appendicitis secondary to amoebic infestation is a rare possibility, especially in endemic areas. If left untreated, significant postoperative morbidity and mortality can result from the spread of amoebic trophozoites and subsequent tissue reaction. Histopathological examination of the resected appendix with demonstration of invasion by the parasite is mandatory for establishing a diagnosis. Careful examination of the specimen is thus of paramount importance.

Updates on the worldwide burden of amoebiasis: A case series and literature review

BACKGROUND

Amoebiasis is an intestinal and tissue parasitic infection caused by the protozoan Entamoeba histolytica. Despite significant medical importance and worldwide dispersion, little is known about the epidemiology and distinct geographical distribution of various clinical forms of amoebiasis in the world. In this study, we present an amoebiasis case series referred to Avicenne Hospital (Bobigny, France) from 2010 to 2022 followed by an overview of the released literature to explore diverse clinico-pathology of amoebiasis and to update the actual epidemiological situation of this parasitosis worldwide.

METHODS

The referred patients underwent a combination of clinical and parasitological examinations and imaging. The study was followed by an overview of released literature performed based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline.

RESULTS

A total of 15 patients with amoebiasis were diagnosed with an average age of 48.5 years old at the occurrence time of infection. Men (78%) were the most affected patients. Most of the cases were reported following a trip to endemic regions, such as Mali, India, Nepal, Algeria, Cameroon or Congo. All of the processed patients exhibited a hepatic amoebiasis. Amoebic abscess was observed in all cases with an average size of 6.3 cm. Of these patients, seven cases (46.7%) benefited from drainage following a risk of rupture or superinfection of the abscess. A compilation of findings extracted from 390 scientific publications via seven major medical databases, allowed us to update the main epidemiological and clinical events that has led to the current worldwide expansion of amoebiasis. We presented a clinical and epidemiological overview of the amoebiasis accompanied with a worldwide illustrative map displaying the current distribution of known amoebiasis foci in each geographical ecozone of Asia, Europe, Africa, Americas, and Australia.

CONCLUSIONS

Although Metropolitan France is not known as an endemic region of amoebiasis, amoebic liver abscess was the most frequent clinical form observed among our 15 patients processed. Most of infected patients had a history of travel to or lived-in endemic areas before arriving in France.

Seroprevalence of Entamoeba histolytica at a voluntary counselling and testing centre in Tokyo: a cross-sectional study

BACKGROUND

Amebiasis, which is caused by Entamoeba histolytica, is a re-emerging public health issue owing to sexually transmitted infection (STI) in Japan. However, epidemiological data are quite limited.

METHODS

To reveal the relative prevalence of sexually transmitted E. histolytica infection to other STIs, we conducted a cross-sectional study at a voluntary counselling and testing (VCT) centre in Tokyo. Seroprevalence of E. histolytica was assessed according to positivity with an ELISA for E. histolytica-specific IgG in serum samples collected from anonymous VCT clients.

RESULTS

Among 2083 samples, seropositive rate for E. histolytica was 2.64%, which was higher than that for HIV-1 (0.34%, p<0.001) and comparable to that for syphilis (rapid plasma reagin (RPR) 2.11%, p=0.31). Positivity for Chlamydia trachomatis in urine by transcription-mediated amplification (TMA) was 4.59%. Seropositivity for E. histolytica was high among RPR/Treponema pallidum hemagglutination (TPHA)-positive individuals and it was not different between clients with and without other STIs. Both seropositivity of E. histolytica and RPR were high among male clients. The seropositive rate for anti-E. histolytica antibody was positively correlated with age. TMA positivity for urine C. trachomatis was high among female clients and negatively correlated with age. Regression analysis identified that male sex, older age and TPHA-positive results are independent risk factors of E. histolytica seropositivity.

CONCLUSIONS

Seroprevalence of E. histolytica was 7.9 times higher than that of HIV-1 at a VCT centre in Tokyo, with a tendency to be higher among people at risk for syphilis infection. There is a need for education and specific interventions against this parasite, as a potentially re-emerging pathogen.

A, Pontón P, Molina GA, Constante JE, Delgado JA. Amebiasis, a rare cause of acute appendicitis

Acute appendicitis is one of the most common abdominal emergencies, even though most cases of appendicitis will be due to obstruction of the appendiceal lumen, in rare occasions and mostly due to poor sanitary conditions a parasitic infection may cause appendicitis. Entamoeba histolytica is a common parasite and has a broad clinical spectrum from an asymptomatic disease to a life-threatening condition. In rare occasions, trophozoites can invade the appendiceal wall causing appendicitis. Preoperative diagnosis of acute amebic appendicitis is usually difficult, yet surgical treatment as in non-amebic appendicitis is the treatment of choice. However, due to the increased rate of postoperative complications associated with acute amebic appendicitis, a course of nitroimidazoles, and increased awareness in basic sanitary measures is usually recommended. We present a case of a 29-year-old woman, she presented with abdominal pain and appendicitis was suspected. After successful surgery, pathology confirmed acute amebic appendicitis.

Prevalence of Parasitic Infections in Surgically Removed Appendices: Parasitological and Histopathological Studies

Intestinal parasites may cause symptoms similar to acute appendicitis. Moreover, the diagnosis of parasitic infections is only done by post-operative histopathological examination of the appendices. Therefore, our aims are to assess the prevalence of intestinal parasitic infections among patients who were be appendectomized at Tanta Hospitals, Egypt and to investigate the possible association between these parasitic infections and appendicitis. To achieve these objectives, we performed a cross-sectional study including 65 patients chosen randomly who had undergone appendectomy over a period of one year from Oct 2015 to Oct 2016. Demographic data were retrieved. Complete blood picture was done. Moreover, appendiceal faecolith were examined macroscopically then by direct smear examination, formol-ether concentration technique, modified Ziehl-Nelseen stain and rapid immunochromatographic test. Histopathological examination of resected appendices was done. We found that parasitic infections were detected in 24.6 % of examined cases. Most of parasitic infections were prevalent in patients belonging to the school age group. Different parasitic infections were detected in the faecolith specimens. Moreover, Enterobious vermicularis adult female and Schistosoma mansoni granuloma were detected in histopathological sections. Also, a spectrum of pathological changes in the appendices was found ranging from lymphoid hyperplasia to acute inflammation with peritonitis. In conclusion, intestinal parasites may cause clinical picture similar to that of acute appendicitis. Therefore, careful attention to clinical history, stool examination and high eosinophilia may aid diagnosis and avoid unnecessary appendectomy. Moreover, the presence of different parasitic stages in the narrow lumen of the appendix may have a role in the development of appendicitis and this needs further studies.

Underestimated Amoebic Appendicitis among HIV-1-Infected Individuals in Japan

Entamoeba histolytica is not a common causative agent of acute appendicitis. However, amoebic appendicitis can sometimes be severe and life threatening, mainly due to a lack of awareness. Also, its frequency, clinical features, and pathogenesis remain unclear. The study subjects were HIV-1-infected individuals who presented with acute appendicitis and later underwent appendectomy at our hospital between 1996 and 2014. Formalin-fixed paraffin-embedded preserved appendix specimens were reexamined by periodic acid-Schiff (PAS) staining and PCR to identify undiagnosed amoebic appendicitis. Appendectomies were performed in 57 patients with acute appendicitis. The seroprevalence of E. histolytica was 33% (14/43) from the available stored sera. Based on the medical records, only 3 cases were clinically diagnosed as amoebic appendicitis, including 2 diagnosed at the time of appendectomy and 1 case diagnosed by rereview of the appendix after the development of postoperative complications. Retrospective analyses using PAS staining and PCR identified 3 and 3 more cases, respectively. Thus, E. histolytica infection was confirmed in 9 cases (15.8%) in the present study. Apart from a significantly higher leukocyte count in E. histolytica-positive patients than in negative patients (median, 13,760 versus 10,385 cells/μl, respectively, P = 0.02), there were no other differences in the clinical features of the PCR-positive and -negative groups. In conclusion, E. histolytica infection was confirmed in 9 (15.8%) of the appendicitis cases. However, only 3, including one diagnosed after intestinal perforation, were diagnosed before the present analyses. These results strongly suggest there is frequently a failure to detect trophozoites in routine examination, resulting in an underestimation of the incidence of amoebic appendicitis.

Comparison of Laparoscopic Appendectomy with open appendectomy in Treating Children with Appendicitis

Objective:

To analyze feasibility and curative effect of laparoscopic appendectomy in the treatment of pediatric appendicitis and compare it with open appendectomy.

Methods:

Two hundred and sixty patients were selected for this study and randomly divided into open appendectomy group (130 cases) and laparoscopic appendectomy group (130 cases). Patients in open appendectomy group underwent traditional open appendectomy, while patients in laparoscopic appendectomy were treated with laparoscopic appendectomy. Incision length, blood loss during operation, duration of operation, time to leave bed, anus exhausting time, time to take food, catheter drainage time, urinary catheterization time, time of using antibiotics, use of pain killer and incidence of complications such as incision infection, residual abscess and intestinal obstruction were compared between two groups.

Results:

We found relevant indexes including length of incision, amount of bleeding and duration of operation in laparoscopic appendectomy group were better than open appendectomy group after surgery; and differences were statistically significant (P<0.05). Indexes such as time to out of bed, time to take food, exhaust time, drainage time, catheterization time and application time and use of antibiotics in laparoscopic appendectomy group were all superior to open appendectomy group, and differences had statistical significance (P<0.05). Incidence of complications in laparoscopic appendectomy group was much lower than open appendectomy group and the difference was statistically significant (P<0.05).

Conclusion:

Laparoscopic appendectomy has advantages of small trauma, sound curative effect, low incidence of complications and rapid recovery and can effectively relieve pain of children suffering from appendicitis. Hence it is worth promotion and should be preferred.