Epidemiology of Domestically Acquired Amebiasis in Japan, 2000–2013

Ishikane, Masahiro; Arima, Yuzo; Kanayama, Atsuhiro; Takahashi, Takuri; Yamagishi, Takashi; Yahata, Yuichiro; Matsui, Takeshi; Sunagawa, Tomimasa; Nozaki, Tomoyoshi; Oishi, Kazunori

doi:10.4269/ajtmh.15-0560

Cited by 21 publications

(19 citation statements)

References 24 publications

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“…Positive urinary TMA for C. trachomatis was highest among clients aged 29 years or younger (8.35%) and showed a negative correlation with age. These results are consistent with national surveillance data, in which diagnosed cases of Chlamydia infection have a peak in the 20s [18], whereas the median age of reported cases of amebiasis is relatively high (50 years in men and 40 years in women) [5, 16]. Considering these findings, E. histolytica infection might be more prevalent among relatively older age groups (40 years or more) whereas Chlamydia infection is more prevalent in relatively younger populations.…”

Section: Resultssupporting

confidence: 89%

Higher seroprevalence ofEntamoeba histolyticathan that of HIV-1 at a voluntary counselling and testing centre in Tokyo

Yanagawa

Nagashima

Gatanaga

et al. 2019

Preprint

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BackgroundAmebiasis, 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.MethodologyTo 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 enzyme-linked immunosorbent assay for E. histolytica-specific IgG in serum samples collected from anonymous VCT clients.Principal FindingsAmong 2,083 samples, seropositivity 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-or 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.ConclusionsSeroprevalence 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.Author summaryAmebiasis caused by Entamoeba histolytica is an increasingly prevalent sexually transmitted infection (STI) in Japan; however, relative to other STIs, the prevalence of E. histolytica has not been fully assessed. We investigated the seropositivity of E. histolytica using serum samples from 2,083 clients of a voluntary counselling and testing centre in Tokyo. E. histolytica seroprevalence (2.64%) was 7.9 times higher than that of HIV-1 (0.31%) and the same as that of syphilis (rapid plasma reagin: 2.11%). Logistic regression analysis showed that E. histolytica seroprevalence tended to be higher among individuals who were male, older, and positive in Treponema pallidum hemagglutination. These results strongly suggest that public health interventions should be considered to control sexual transmission of E. histolytica infection, which is currently neglected in Japan.

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Section: Resultssupporting

confidence: 89%

Higher seroprevalence ofEntamoeba histolyticathan that of HIV-1 at a voluntary counselling and testing centre in Tokyo

Yanagawa

Nagashima

Gatanaga

et al. 2019

Preprint

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“…However, in clinical settings similar to the 2 present patients, the difference between intestinal colonization and invasive colitis is often uncertain. [9][10][11][12] Our patients had minimal symptoms but showed macroscopically visible intestinal ulcers upon colonoscopy and microscopically identified inflammation caused by E. histolytica in biopsy samples. This difference is presumably because disease severity (colonization or colitis) in amebiasis is not currently determined using pathophysiological criteria but is based on patients' symptoms.…”

Section: Treatment For Endoscopically Diagnosed Amebic Colitismentioning

confidence: 64%

Two cases of endoscopically diagnosed amebic colitis treated with paromomycin monotherapy

et al. 2020

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Patient 1 who was a 43-year-old male was first referred to our institute because of an allergic reaction to metronidazole with oral mucosal erosions during his sixth treatment for amebic colitis. He had a history of 5 recurrent episodes of amebic colitis (last treatment was 3 years earlier, using metronidazole followed by paromomycin) (S1 Table). Besides oral mucosal erosions, he complained of soft or loose stools 2 to 3 times daily without abdominal pain or fever. Although we proposed admission for close observation during his treatment, he selected outpatient treatment at a nearby hospital. Three months later, the patient returned to our hospital because his wife was also diagnosed with Entamoeba histolytica infection. The couple operated a Japanese inn in a suburban area of Tokyo. They had no travel history to developing countries within the past 10 years. He denied extramarital sexual intercourse and oral-anal sexual contact. He did not have any past histories, except for recurrent amebiasis. There were no reported outbreaks of gastrointestinal diseases for over 10 years in the couple's residential area. Results of a blood examination showed no particular abnormalities (Table 1). Although a direct microscopic examination was negative for any protozoa, the patient's stool tested positive for E. histolytica with polymerase chain reaction (PCR). Total colonoscopy showed white-coated ulcerative lesions at the cecum (Fig 1A). In a pathological examination, Entamoeba was identified on the surface mucosa in a biopsy sample (S1 Fig).We treated the patient with a lumen-active agent (paromomycin monotherapy) because (1) he had a past history of acute oral mucosal lesions owing to metronidazole, (2) tinidazole is not approved to treat amebiasis in Japan, and (3) his symptoms of E. histolytica were mild. Negative PCR results for E. histolytica were confirmed in stool samples taken at 1, 2, and 4 months after treatment. Follow-up colonoscopy showed that lesions of the cecum were completely resolved ( Fig 1C).Patient 2 was a 43-year-old female and the wife of patient 1. She was referred to our institute because of Entamoeba infection as confirmed on microscopic examination of a stool sample. One month before diagnosis, she had a positive fecal occult blood test result in an advanced health check. Dysentery, abdominal pain, and fever were not documented at referral. She denied extramarital sexual intercourse. She had a high anti-E. histolytica antibody titer (1:800). Direct microscopy of stool samples showed the cystic form of Entamoeba. E. histolytica was confirmed using PCR (Table 1). Total colonoscopy showed multiple, white-coated, ulcerative lesions from the cecum to the sigmoid colon ( Fig 1B). The patient was treated with paromomycin monotherapy because her symptoms were mild, and she wished to avoid the PLOS NEGLECTED TROPICAL DISEASES PLOS Neglected Tropical Diseases | https://doi.org/10.

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“…Second, we selected HIV-1-infected individuals for the present analyses because they are affected by E. histolytica to a greater extent than non-HIV ones in our country (10, 21). It is expected that the rate of amoebiasis is higher among immunocompromised HIV-1-infected individuals than among uninfected ones (22–24), although it was reported that clinical presentations are not influenced by the presence of HIV-1 (19, 25, 26).…”

Section: Discussionmentioning

confidence: 99%

“…HIV-1-infected men who have sex with men (MSM) are recognized as risk factor for sexually transmitted amoebiasis in these countries (7–9). Importantly, the number of cases of amoebiasis in Japan is increasing annually, mainly as STIs (10). …”

Section: Introductionmentioning

confidence: 99%

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

et al. 2017

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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.

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Epidemiology of Domestically Acquired Amebiasis in Japan, 2000–2013

Cited by 21 publications

References 24 publications

Higher seroprevalence ofEntamoeba histolyticathan that of HIV-1 at a voluntary counselling and testing centre in Tokyo

Higher seroprevalence ofEntamoeba histolyticathan that of HIV-1 at a voluntary counselling and testing centre in Tokyo

Two cases of endoscopically diagnosed amebic colitis treated with paromomycin monotherapy

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

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