Amebiasis in institutions for the mentally retarded in Kanagawa Prefecture, Japan

A parasitologic survey of 620 mentally retarded patients, institutionalized in five different facilities in Kanagawa Prefecture, revealed a high incidence (12.6%) of infection with Entamoeba histolytica. A concomitant serologic survey, by the indirect fluorescent antibody test, gave a much higher incidence (26.5%). Moreover, most zymodeme patterns of the amebae isolated from infected individuals were of a pathogenic type (Zymodeme II). Our findings demonstrate that the mentally retarded in Japan, as in the United States, still are plagued by a high rate of amebic infection.     

The Intradermal Reaction in Amebiasis

Studies on the amebiasis skin test were carried out in Amerindians living on reserves of Northern Saskatchewan. Results indicate the skin test to be highly sensitive in patients with acute amebic dysentery and in individuals with a history of amebic disease. A high percentage of asymptomatic school children living on a reserve where amebic disease is of common occurrence were also skin reactors. In a similar group of school children living on a reserve where amebic disease had never been reported but where E. histolytica infection rates are high there were very few reactors. A control group of white adults living in a non-endemic area were uniformly negative to the skin test. A comparison with the indirect hemagglutination test showed a good general correlation, but the skin test proved to be more accurate in cases of acute amebic dysentery in children 5 years of age or under. The skin test appears to have potential as a diagnostic technique and may be of considerable value in defining endemic areas of amebic disease.     

Amebiasis in HIV-1-infected Japanese men: clinical features and response to therapy

Invasive amebic diseases caused by Entamoeba histolytica are increasing among men who have sex with men and co-infection of ameba and HIV-1 is an emerging problem in developed East Asian countries. To characterize the clinical and epidemiological features of invasive amebiasis in HIV-1 patients, the medical records of 170 co-infected cases were analyzed retrospectively, and E. histolytica genotype was assayed in 14 cases. In this series of HIV-1-infected patients, clinical presentation of invasive amebiasis was similar to that described in the normal host. High fever, leukocytosis and high CRP were associated with extraluminal amebic diseases. Two cases died from amebic colitis (resulting in intestinal perforation in one and gastrointestinal bleeding in one), and three cases died from causes unrelated to amebiasis. Treatment with metronidazole or tinidazole was successful in the other 165 cases. Luminal treatment was provided to 83 patients following metronidazole or tinidazole treatment. However, amebiasis recurred in 6 of these, a frequency similar to that seen in patients who did not receive luminal treatment. Recurrence was more frequent in HCV-antibody positive individuals and those who acquired syphilis during the follow-up period. Various genotypes of E. histolytica were identified in 14 patients but there was no correlation between genotype and clinical features. The outcome of metronidazole and tinidazole treatment of uncomplicated amebiasis was excellent even in HIV-1-infected individuals. Luminal treatment following metronidazole or tinidazole treatment does not reduce recurrence of amebiasis in high risk populations probably due to amebic re-infection.     

Efficacy and safety of paromomycin for treating amebiasis in Japan

The clinical management of amebiasis is a growing concern, particularly among human immunodeficiency virus (HIV)-infected individuals who are predisposed to severe illness. Treatment with a luminal amebicide is strongly recommended following acute-stage treatment with a nitroimidazole. In 2004, the Japanese Research Group on Chemotherapy of Tropical Diseases introduced paromomycin, which was not nationally licensed, and offered it to a number of patients. From 2004 to 2011, 143 case records of amebiasis (123 with amebic colitis, 16 with amebic liver abscess, and 4 with both) in which patients were treated with paromomycin, mainly 1500 mg/day for 9 or 10 days following metronidazole treatment, were submitted. Among 123 evaluable cases, 23 (18.7%) experienced possible adverse effects, the most common being diarrhea (17/123, 13.8%) and other gastrointestinal problems that were resolved after the completion or discontinuation of treatment. In addition, single cases of bloody stools associated with Clostridium difficile colitis, skin rash, and the elevation of liver enzymes were also reported, although the causal relationship was not clear. HIV infection did not appear to increase the incidence of adverse drug effects. Each of the 11 asymptomatic or mildly symptomatic amebic colitis cases became negative for stool cysts after paromomycin treatment. Paromomycin was shown to be safe and well tolerated, as well as effective in a special subset of amebic colitis cases.     

The frequency of Toxocara infection in mental retarded children

Human toxocariasis is commonly seen in places where stray and Toxocara canis-infected dog population is high. There is a strong correlation between frequency of Toxocara infection, life style, and infection risk. Institutionalization of mental retarded patients increases to risk of toxocariasis. In this study, we aimed at investigating the frequency of Toxocara infection among children with mental retardation not requiring institutionalization. The study included 96 cases, who had educatable mental retardation and 85 healthy subjects who comprised the control group. Anti-Toxocara IgG or IgM antibodies were investigated in all serum samples, using ELISA method. The frequency of Toxocara infection was found significantly higher in mental retarded cases than in those in the control group (18.8% and 7.1% respectively) (p < 0.05). There was no significant difference between mental retarded children and the control group in terms of mean age, age groups, gender, owning dogs and cats and duration of their ownership, socio-economic level and behavioural factors, and personal hygiene (p > 0.05). We did not find any significant difference between Toxocara seropositive and seronegative mental retarded children in terms of demographic factors and epidemiological factors that could increase the risk of Toxocara infection (p > 0.05). The present study is the first seroprevalence study carried out with a mental retarded group not requiring institutionalization. Determination of high frequency of Toxocara infection suggests that these subjects constitute a risk factor for Toxocara infection, which may be attributed to their behavioural patterns.     

Cytopathologic and genetic diagnosis of pulmonary amebiasis: a case report

BACKGROUND: Amebiasis is a parasitic infection with Entamoeba histolytica. Pulmonary amebiasis is rare since the infection is commonly manifested as amebic colitis or liver abscess. Most pleuropulmonary amebiasis is seen in patients with amebic liver abscesses. A pulmonary amebic lesion without either a liver abscess or amebic colitis is extremely rare. Thus, reported cases of sputum cytologic diagnosis of a pulmonary amebic lesion from a patient without a liver abscess are also very rare. CASE: A 53-year-old man presented with a dry cough and mild fever. Chest radiography revealed an abnormal solitary mass lesion in the right upper lung field. The clinical diagnosis was a bacterial lung abscess. Sputum cytologic examination demonstrated many trophozoites of E. histolytica. Following sputum cytodiagnosis, serologic tests revealed a slightly high but almost normal titer of IgG antibodies to E. histolytica, indicating the possible presence of the pathogen. Polymerase chain reaction (PCR) using E. histolytica-specific primers for DNA extracted from the sputum sample revealed specific DNA product. CONCLUSION: Pulmonary amebiasis without either a liver abscess or amebic colitis must be distinguished from bacterial abscesses and neoplastic disease. A sputum cytologic examination combined with PCR for DNA extracted from a sputum sample is a good approach to the diagnosis of a pulmonary amebic abscess.     

Evaluation of indirect fluorescent antibody test and enzyme-linked immunosorbent assay for diagnosis of hepatic amebiasis in Bangladesh

Serum samples of 31 amebic liver abscess (ALA) patients, 8 amebic hepatitis (AH) patients, and 60 controls were tested for anti-amebic IgG by enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody tests (IFAT). Sera of 29 (93.6%) ALA and 6 (75%) AH patients and 2 (3.3%) control subjects were positive by IFAT. Anti-amebic antibody titer above the cutoff point (= 0.168; x + 2 SD of control sera) was observed in sera of 27 (87%) ALA, 4 (50%) AH, and 1 (1.7%) control by ELISA. All the 8 pus samples were positive for anti-amebic antibodies by IFAT and ELISA. Sensitivity of ELISA was 87% for ALA, with a positive predictive value of 0.96, and 50% for AH cases, with a positive predictive value of 0.80. The sensitivity of IFAT was 93.6% for ALA, with a positive predictive value of 0.94, and 75% for AH, with a positive predictive value of 0.75. When pus samples were tested, the sensitivity was 100% for both tests. The specificity was 98.3% for ELISA and 96.7% for IFAT. Although not significant, IFAT was found more sensitive than ELISA (P>0.05).     

CONTROL OF DIARRHEAL DISEASES IN CALIFORNIA STATE HOSPITALS FOR RETARDED CHILDREN

The three California state hospitals for mentally retarded persons have been having a severe problem with amebic and bacillary dysentery and with other infectious diseases of the gastrointestinal tract. At Sonoma, the oldest of these hospitals, this problem is known to have existed for many years. Improved medical and nursing staffing and the use of antibiotics and other effective drugs developed in recent years have greatly lowered morbidity and mortality rates in these institutions. However, in themselves these measures have not been effective in lowering the incidence of infection.Studies have demonstrated that mass treatment of cottage groups known to have a high incidence of amebic infection has resulted in control of this disease where such mass treatment was followed by adequate laboratory follow-up, with isolation and retreatment of treatment failures. Where mass treatment of such groups has been carried out without such laboratory followup, there was a rapid return to the previous high incidence of infection.Statistics show that these diseases are a serious threat to employees working in these institutions. Increasing attention is being paid to the potential threat to the surrounding communities and the state as a whole from the focus of infection present in these hospitals.     

陕西圈养珍稀野生动物肠道寄生虫感染及其形态观察

2007年11～12月对陕西省珍稀野生动物抢救饲养研究中心中的珍稀野生动物进行了寄生虫感染情况及其种类、形态的观察.采用生理盐水涂片法、碘液染色法对18种75头/只野生动物的粪便进行检查,对检出的寄生虫进行数码显微摄片.结果共检出11种寄生虫,总感染率为88.9%,以芽囊原虫(Blaaocyais sp.)、阿米巴原虫感染较为突出.     

Asymptomatic cyst passers of Entamoeba histolytica but not Entamoeba dispar in institutions for the mentally retarded in Japan

Entamoeba histolytica/Entamoeba dispar was isolated from 50 asymptomatic amebic cyst passers in three institutions for the mentally retarded in Kanagawa Prefecture, Japan. To distinguish between E. histolytica and E. dispar, the isolates were analyzed by PCR, reactivity to monoclonal antibodies, and zymodemes. All isolates were identified as E. histolytica. The results lead us to conceive that, in Japan, E. histolytica is predominant even in asymptomatic cyst passers.     

Patients treated for amebic liver abscess develop cell-mediated immune responses effective in vitro against Entamoeba histolytica

We studied the afferent and efferent cell-mediated immune response in 15 patients treated for amebic liver abscess. Patients had a lower T4 to T8 ratio (1.25 +/- 0.65) compared with age- and sex-matched controls (1.89 +/- 0.44, p less than 0.01) due to a decrease in T4-"helper" cells and an increase in T8-"suppressor" cells (p less than 0.01). The in vitro proliferative response of patient T lymphocytes to the plant mitogen concanavalin A (Con A) was depressed; responses to phytohemagglutinin were not. The proliferative response of patient lymphocytes to an amebic soluble protein preparation (SPP) was greater than the mitogenic response seen in control lymphocytes (mean of 68,300 delta cpm and 22,300 delta cpm, respectively, p less than 0.001), correlated with the T4 to T8 ratio (p less than 0.05) and the duration of time from initiation of antiamebic therapy (p less than 0.01). Supernatants from patient lymphocytes exposed to the amebic SPP activated normal monocyte-derived macrophages to kill virulent axenic E. histolytica trophozoites (p less than 0.001); patient monocyte-derived macrophages activated by Con A-elicited lymphokine could also kill amebae. Finally, when incubated with the amebic SPP for 5 days, T lymphocytes from patients were able to kill virulent amebae (p less than 0.005); patient T lymphocytes not exposed to the amebic SPP or control T lymphocytes incubated for 5 days with the amebic SPP were not cytotoxic to E. histolytica trophozoites. In summary, after cure of amebic liver abscess, specific cell-mediated immune mechanisms develop that are effective in vitro against the parasite.     

Bacterial infection in patients with visceral leishmaniasis

In an analysis of 63 hospitalized cases with visceral leishmaniasis, the clinical or post-mortem diagnosis of bacterial infection was performed in 33; 13 (39.3%) patients had respiratory infection, 4 (12.1%) had skin infection, 4 had urinary tract infection, 3 (9.0%) showed ear infection and 2 (6.6%) had infection of the oral cavity. It is worth mentioning that in 7 (21%) cases there was infection in multiple sites. Gram positive and/or Gram negative organisms were isolated from 10 patients. In only two (autopsied) cases, infection with less common organisms was recorded, one with disseminated candidiasis and another with disseminated tuberculosis. Death occurred in 9 of the 63 cases, and in 8 of these, concomitant bacterial infection of importance was documented. Patients who had serum globulins lower than 4 g% had significantly more infection (p less than 0.05) than patients with globulin levels higher than 4 g%; there was no significant difference when the number of leucocytes and neutrophils in patients with associated infection was compared with those in patients without bacterial infection. The present study demonstrates that bacterial infection frequently occurs in patients with visceral leishmaniasis, and indicates an unfavourable prognosis. Even though the mechanism of increased susceptibility to infection in this condition was unclear, the widespread range of infections and of infective agents, suggests a multifactorial process.     

Experimental muscular amebiasis in hamsters as a biological model.

Trophozoites of Entamoeba histolytica maintained in vitro in Pavlova's medium were inoculated by deep intramuscular injection into the proximal left hindleg of hamsters. Thioglycollate medium was utilized as a successful vehicle to induce the infection. The invasion of the muscular tissue by the vegetative forms caused the formation of abscesses with great destruction of muscular fibers. The lesions were limited to the muscular tissue of the femoral area. The number of trophozoites, the medium of thioglycollate as a vehicle, the volume of the inoculum and the trauma caused by the needle were important elements in the evolution of the muscular amebic abscesses. A limited trial of the amebicidal activity of metronidazole utilizing the amebic intramuscular infection was also performed.     

内毒素和降钙素原在妇科术后尿路感染中的鉴别诊断价值

目的评价中段尿内毒素和血清降钙素原在妇科术后不同种类细菌尿路感染中的鉴别诊断价值。方法收集临床1205例妇科术后患者中段尿进行细菌培养及内毒素检测,同时对患者进行血清降钙素原检测,比较结果对尿路感染的鉴别诊断价值。结果1205份标本中尿培养出阳性350例,感染率为29．04％,其中298例为均存在留置导尿管,而在剩余400例尿培养阴性的患者中仅仅120例留置导尿管。两组之间差异有统计学意义（χ2=26．78,P〈0．05）。其中革兰阴性杆菌189例（54％）,革兰阳性菌112例（32％）,真菌49例（14％）。在三组患者中,中段尿内毒素在革兰阴性菌引起的术后尿路感染较革兰阳性菌和真菌的患者中明显升高,差异均有统计学意义（P〈0．05）。而对于血清降钙素原在革兰阴性菌和革兰阳性菌感染的患者明显高于真菌尿路感染的患者,差异均有统计学意义（P〈0．05）。而在革兰阴性菌和革兰阳性菌感染的患者中差异无统计学意义（P〉0．05）。结论妇科术后尿路感染与留置导尿管密切相关,革兰阴性菌是引起妇科术后尿路感染的主要致病菌,中段尿内毒素有助于鉴别诊断出革兰阴性菌引起尿路感染,而血清PCT升高时则有助于排除真菌尿路感染。     

Increased risk for Entamoeba histolytica infection and invasive amebiasis in HIV seropositive men who have sex with men in Taiwan

Background

Incidence of Entamoeba histolytica infection and clinical manifestations and treatment response of invasive amebiasis (IA) in HIV-infected patients have rarely been investigated before.

Methodology/Principal Findings

At the National Taiwan University Hospital, medical records of HIV-infected patients who received a diagnosis of IA between 1994 and 2005 were reviewed. The incidence of amebiasis was investigated in serial blood and stool samples from 670 and 264 HIV-infected patients, respectively, using serological and specific amebic antigen assays. DNA extracted from stool samples containing E. histolytica were analyzed by PCR, sequenced, and compared. Sixty-four (5.8%) of 1,109 HIV-infected patients had 67 episodes of IA, and 89.1% of them were men having sex with men (MSM). The CD4 count at diagnosis of IA was significantly higher than that of the whole cohort (215 cells/µL vs. 96 cells/µL). Forty episodes (59.7%) were liver abscesses, 52 (77.6%) colitis, and 25 (37.3%) both liver abscesses and colitis. Fever resolved after 3.5 days of metronidazole therapy (range, 1–11 days). None of the patients died. The incidence of E. histolytica infection in MSM was higher than that in other risk groups assessed by serological assays (1.99 per 100 person-years [PY] vs. 0 per 100 PY; p<0.0001) and amebic antigen assays (3.16 per 100 PY vs. 0.68 per 100 PY; p = 0.12). In multiple logistic regression analysis, only MSM was significantly associated with acquisition of E. histolytica infection (adjusted odds ratio, 14.809; p = 0.01). Clustering of E. histolytica isolates by sequencing analyses from geographically-unrelated patients suggested person-to-person transmission.

Conclusions/Significance

HIV-infected MSM were at significantly higher risk of amebiasis than patients from other risk groups. Despite immunosuppression, amebic liver abscesses and colitis responded favorably to treatment.     

Entamoeba histolytica: antibody responses and lymphoreticular changes in gerbils (Meriones unguiculatus) in response to experimental liver abscess and amebic extract infection

Antibody responses and histological changes in hepatic lymph nodes and spleen of gerbils (Meriones unguiculatus) during the course of experimental hepatic amebiasis (5-60 days), or in those injected with extracts of Entamoeba histolytica, are described. Lymph node and spleen responses in infected animals paralleled the proliferation of the amebic liver abscess. However, spleen follicle responses were similar in animals that received low or high doses of the amebic extract and differed histologically from those with amebic liver abscess. Liver abscesses, up to 30 days postinfection (pi), doubled in weight between 10 and 15 and between 20 and 30 days pi. Early changes (10 days pi) in the lymphoreticular tissues were characterized by increased size and weight of the organs, hyperplastic follicles, and blastogenesis in the T-dependent areas. At 20 and 30 days pi, the size of spleen follicles increased and there was depletion of lymphocytes from the periarterial area (PAA), as well as gross extension of the red pulp, accompanied by extramedullary erythropoiesis and megakaryocytosis. The paracortical areas (PCA) of lymph nodes were depleted of lymphocytes and histiocytosis throughout the organ, and there was intense plasma cell activity in the medulla. At 60 days pi, lymphocyte repopulation was noted in the PCA and PAA; germinal centers were depleted of blast cells and the spleen red pulp had contracted. Antiamebic antibody titers were low throughout the infection. Changes in the cellularity of the lymphoid organs are discussed in relation to the proliferation of the amebic liver abscesses in infected animals and in those which were injected with the amebic extract.     

Tinea unguium in the north-west of Iran (1996-2004)

Tinea unguium is a common mycosis in many part of the world including Iran. The prevalence of this mycosis varied depending on time, health level and geographical location. To stabilise the etiological, epidemiological and risk factors of tinea unguium in North-west Iran, a study of patients with suspected dermatophyte infections of their nails was carried out between 1996 and 2004. During this study 590 (354 females and 236 males) patients with clinical presentation of fungal infection in fingernails, toenails or in the both sites, were investigated using direct microscopy and culture of clinical samples. Tinea unguium was documented in 41 cases (7%) and among positive cases, 16 cases (39% total positive cases) were female and 25 cases (61% total positive cases) were male. Seventeen patients (41% total positive cases) had tinea unguium in their finger nails and 24 patients (59% total positive cases) had infection in their toe nails. According to the isolated etiologic agent, 66% (19 cases) of tinea unguium infections were caused by zoophilic drematophytes, 31% (9 cases) were caused by anthropophilic drematophytes and 3% (1 case) were caused by geophilic dermatophytes. With regard of sex, tinea unguium did not show a significant difference. The highest prevalence of tinea unguium was found in patients between 11 and 40 years of age. In conclusion the current results identified the etiological agents and epidemiological aspects of tinea unguium in North-west Iran. Tinea unguium in this region is associated with animal husbandry and direct or indirect contact with their products (wool, leather).     

Macroorchidism and fragile X in mentally retarded males

Summary One hundred and seventy eight males resident in an institution for the mentally retarded were screened clinically for the presence of macroorchidism, using the standard orchidometer. In this way 52 males with a testicular volume of 25 ml and over were found. Of these, 11 had pronounced macroorchidism (above 25 ml). All 52 males were examined cytogenetically for the fragile X. Two patients with pronounced macroorchidism showed this abnormality. Although the other nine patients with pronounced macroorchidism were reexamined with FUdR-addition to blood cultures, no further cases positive for the fragile X were found. Also, the thyroid function as well as the prolactin level in serum were investigated in all 52 males. No significant abnormalities were found. The high incidence of macroorchidism in mentally retarded males is underlined; however, it is suggested that the definition of macroorchidism should take into account several parameters.     

Entamoeba histolytica: identification of a distinct beta2 integrin-like molecule with a potential role in cellular adherence

Entamoeba histolytica infection causes dysentery, intestinal colitis, and hepatic abscess in an estimated 50 million people worldwide. Attachment of E. histolytica trophozoites to intestinal epithelium and vascular endothelium during liver metastasis results in an inflammatory process. We report the identification of a distinct amebic beta2 integrin (CD18)-like molecule which affords adherence to TNF-alpha-activated endothelial cells. Data from flow cytometry and indirect immunofluorescence assays suggest the amebic beta2 integrin was localized to focal adhesion plates and was present in both E. histolytica and Entamoeba dispar. The amebic beta2 integrin appeared to be distinct from the amebic Gal/GalNAc lectin based on recombinant expression, amebic colocalization, and ELISA studies. Trophozoite adherence to endothelial cells expressing ICAM-1 (CD54) following activation with TNF-alpha or ICAM-1-transfected CHO cells was specifically inhibited with anti-CD18 or anti-CD54 MAbs. In summary, evidence in support of a distinct beta2 integrin-like molecule participating in amebic adherence to TNF-alpha-activated endothelial cells expressing ICAM-1 is presented. The presence of integrin-dependent binding may allow trophozoites to opportunistically adhere to activated intestinal epithelium or vascular endothelium expressing ICAM-1 during amebic colitis or hepatic abscess.     

A comparison of glycan expression and adhesion of mouse-adapted strains and clinical isolates of Helicobacter pylori

The role of Mycoplasma pneumoniae infection as a trigger for asthma exacerbations is well supported in previous studies. This study was designed to investigate the role of M. pneumoniae infection in acute exacerbation of asthma in children. A total of 150 patients (110 males, 40 females) were studied and immunoglobulin M (IgM) antibodies to M. pneumoniae were detected by enzyme-linked immunosorbent assay (ELISA), and PCR amplification was performed for the P1 gene to associate M. pneumoniae infection with asthma. As compared with 33 children with asthma, only two of the control subjects had positive IgM titers for M. pneumoniae , which was statistically significant ( P =0.002). A total of 15 children with asthma were positive by PCR for the P1 gene while none of the controls had a positive PCR. Of these positive cases, 24 cases were positive only by ELISA, six were positive only by PCR and nine patients were found to be positive by both ELISA and PCR. All the clinical characteristics of the patients at baseline were comparable between the moderate and the severe group of patients statistically, except for the peak expiratory flow rate. Mycoplasma pneumoniae infection was found to have a significant association with acute exacerbation in the moderate group of asthma patients by PCR ( P =0.01). These data suggest that M. pneumoniae infection may contribute to asthma exacerbation.