Intestinal parasitic infections in an institution for the mentally retarded

Comparison of miRNA profiles in the immune response of pediatric acute appendicitis and pediatric enterobiasis patients caused by Enterobius vermicularis

BACKGROUND

The aim of this study was to determine and compare the miRNA profile in the immune response with the parasite in pediatric patients with acute appendicitis caused by Enterobius vermicularis and in pediatric patients with enterobiasis.

METHODS

A total of 30 tissue samples, which were operated with the diagnosis of pediatric acute appendicitis in the last 10 y and Enterobius vermicularis was detected by histopathological findings, were analyzed. In addition, blood samples were taken from 30 pediatric patients diagnosed with enterobiasis for this study. The miRNAs that activate T and B cells were evaluated by a quantitative real-time PCR, statistically calculated within ΔΔCt values, and fold changes were evaluated by Welch's T test, in which p<0.5 was considered to be significant.

RESULTS

It was found that 48 out of 136 (35.3%) miRNAs differed between the pediatric patient and healthy control groups. It was determined that 22 (57.9%) of the different miRNAs were T cell activating miRNAs and 26 (68.4%) were B cell activating miRNAs. While there was a significant difference in miRNA values activating T cells in two patient groups (p<0.01), there was no significant difference in miRNA values activating B cells (p>0.01).

CONCLUSIONS

In the study, although Enterobius vermicularis was the causative agent in both patient groups, it was revealed that the immune response of patients with acute appendicitis was more affected than enterobiasis patients.

Vulvovaginitis due to Enterobius vermicularis in a girl and epidemic enterobiasis in her family

Key Clinical Message

Here we present a case of a 4-year-old girl who suffered from vulvovaginitis caused by Enterobius vermicularis. All members of her family were also infected by this helminth. Treatment with mebendazole was administered to all family members and it was found that the entire family had been cured.

Abstract

Vulvovaginitis, an inflammation of the vulvovaginal mucous membranes, is a common reason for pediatric gynecology consultations. One of the causes of this condition is a parasitic worm known as Enterobius vermicularis (E. vermicularis). In girls, adult worms can infiltrate the vagina and release eggs, leading to the development of vulvovaginitis. Furthermore, these worms have the ability to invade the endometrial cavity too. Here we present a case of a 4-year-old girl who suffered from vulvovaginitis caused by E. vermicularis. All members of her family were also infected by this parasitic helminth. In the vaginal sample, apart from the eggs, the female adult worm was observed under the microscope. Treatment with mebendazole was administered to all family members, and their progress was followed for a period of 3 weeks, during which it was found that the entire family had been cured. This patient experienced significant improvement in symptoms related to severe anxiety, nervousness, vaginal inflammation, itching, and vulvovaginitis caused by E. vermicularis. To prevent infection by E. vermicularis, it is crucial to disinfect underwear and bed sheets. In kindergartens, the spread of this parasite should not be underestimated, and asymptomatic individuals who have been exposed to infected persons should receive treatment to prevent an epidemic. Maintaining cleanliness and hygiene, especially after using the toilet, is of the most importance, particularly for girls who are more susceptible to E. vermicularis infection. Additionally, it is essential for all family members to be aware of the transmission routes of this parasite.

Prevalence of Intestinal Parasites and Associated Factors Among Psychiatric Patients Attending Felege Hiwot Comprehensive Specialized Referral Hospital, Northwest Ethiopia

Background

Intestinal parasitic infections are among the major public health problems in resource-poor countries such as Ethiopia. Certain segments of the population such as psychiatric patients are believed to be at higher risk of infection because of their poor hygiene practices. However, information on the prevalence and contributing factors among psychiatric patients is limited in Ethiopia.

Methods

A facility-based cross-sectional study was conducted among 432 psychiatric patients attending Felege Hiwot Comprehensive Specialized Referral Hospital, Northwest Ethiopia from May to July 2020. Participants were selected using a systematic random sampling technique. Data on socio-demography and associated factors were collected using a pre-tested structured questionnaire. Stool sample was collected and processed for parasitological examination using direct wet mount, modified Richie’s concentration, Kato-Katz and modified Ziehl-Neelsen staining techniques following standard protocols. Data were entered and analyzed using Statistical Package for the Social Sciences software version 20. The prevalence of intestinal parasitosis and associated factors were computed by descriptive statistics and binary logistic regression at 95% confidence interval (CI), respectively. Association between variables was considered statistically significant only if P-value <0.05 at 95% confidence level.

Results

A total of 168 (38.9%) participants were positive for at least a single species of intestinal parasite. Hookworm, Entamoeba histolytica/Entamoeba dispar and Ascaris lumbricoides were the most frequent parasites, detected in 74 (17.1%), 47 (10.9%) and 37 (8.6%) participants, respectively. Double infection was detected in 16 (9.5%) participants where 8 (4.8%) had hookworm and Ascaris lumbricoides co-infections. Not washing raw fruits and vegetables before eating (adjusted odds ratio = 8.402; 95% CI: 3.055–23.109; P <0.001) and having a psychiatric diagnosis other than bipolar disorder (adjusted odds ratio = 3.104; 95% CI: 1.334–7.222; P = 0.009) were significantly associated with intestinal parasitic infections.

Conclusion

The prevalence of intestinal parasites among psychiatric patients was significant. Therefore, improving hygiene practice and implementing regular screening for intestinal parasitic infection among psychiatric patients are recommended so as to control parasite transmission and improve the health of psychiatric patients.

Intestinal parasites among intellectually disabled individuals in Iran: a systematic review and meta-analysis

BACKGROUND

Poor self-care skills and personal hygiene resulted from limitations in learning and understanding, put intellectually disabled individuals at greater risk for intestinal parasitic infections (IPIs). Despite several regional reports in Iran, the overall burden on IPIs among intellectually disabled individuals is poorly understood. Hence, the present study aimed to estimate the pooled prevalence of IPIs among intellectually disabled individuals in Iran.

METHODS

Using the PRISMA guidelines, we conducted a systematic review and meta-analysis of data retrieved from seven electronic databases (PubMed, Web of Science, Scopus, Embase, and ProQuest for English articles, as well as SID and Magiran for Persian) from their inception up to December 2020. Pooled prevalence was estimated using a random-effects model with a 95% confidence interval (CI) and depicted as a forest plot, while heterogeneity was evaluated using Cochran's Q-test.

RESULTS

Exactly 1263 of the 3004 intellectually disabled individuals examined by 14 studies across 10 provinces of Iran were positive for IPIs. Overall pooled prevalence estimate was 41% (95% CI 29-53%) with a range of 21% (95% CI 10-32%) to 68% (95% CI 55-80%) across sub-groups. Entamoeba coli (16.2%; 95% CI 10.3-22%), Blastocystis spp. (12.2%; 95% CI 7.2-17.2%), and Giardia duodenalis (11.9%; 95% CI 7.4-16.3%) were the most prevalent protozoan species. In terms of helminthic agents, the most prevalent species were Enterobius vermicularis (11.3%; 95% CI 6.3-16.3%) followed by Strongyloides stercoralis (10.9%; 95% CI 5.0-16.9%) and Hymenolepis nana (2.8%; 95% CI 0.4-5.2%) CONCLUSION: IPIs are highly prevalent among intellectually disabled individuals in Iran. Improving the health status and implementing infectious disease prevention strategies in rehabilitation centers, health promotion interventions to improve personal hygiene of intellectually disabled individuals, as well as utilize sensitive diagnostic methods besides routine stool examination techniques, and treatment of infected individuals will help in the control of these infections among intellectually disabled individuals.

Autochthonous Human and Canine Strongyloides stercoralis Infection in Europe: Report of a Human Case in An Italian Teen and Systematic Review of the Literature

Autochthonous human and canine strongyloidiasis is reported in Europe but is unclear whether the transmission of infection still occurs. We report a previously unpublished human case in an Italian teen and perform a systematic review of literature on autochthonous human and canine strongyloidiasis in Europe to investigate the current dynamic of transmission. Overall, 109 papers published after 1987 were included and one previously unpublished Italian case was added. Eighty case reports were retrieved and 42 of them (52.5%) had severe strongyloidiasis. Most cases were diagnosed in Spain, Italy and France. The median age was 58, the most represented age group was 61-70 years, 11 patients were under 30, and 7 of them were diagnosed after 2000. Epidemiological studies on human strongyloidiasis showed prevalence ranging from 0.56% to 28%. Overall, agriculture work, mine work and walking barefoot were the most commonly reported risk factors for infection. Canine strongyloidiasis was reported mainly in Italy (68 cases), but a few cases occurred also in Iceland, Finland, England, Germany, France, Switzerland, Russia, Slovakia, Romania and Greece. Autochthonous strongyloidiasis is still reported in Europe and sporadic transmission still occurs. Health care professionals should be aware of this issue to identify infected subjects and avoid adverse outcomes, especially in immunosuppressed patients. Further investigations are needed to clarify the zoonotic transmission of this nematode.

A case of Strongyloides hyperinfection syndrome in the setting of persistent eosinophilia but negative serology

Strongyloides stercoralis is a unique intestinal nematode with the ability to replicate and complete its life cycle without leaving the host. We report a fatal case of Strongyloides hyperinfection syndrome in a patient who had persistent eosinophilia for several years but negative Strongyloides serology. Our case suggests that ELISA serologies cannot solely be relied upon to diagnose Strongyloides stercoralis infection; history and clinical judgment remain crucial to this diagnosis.

Prevalence and Correlates of Intestinal Parasites among Patients Admitted to Mirembe National Mental Health Hospital, Dodoma, Tanzania

BACKGROUND

Neglected tropical diseases continue to be one of the leading causes of morbidity and mortality in the developing world. Psychiatric patients are among groups at risk for parasitic infection although control and monitoring programs largely overlook this population. This study aimed at determining prevalence and factors associated with intestinal parasitic infection among patients admitted to a psychiatric facility.

METHOD

The study followed cross-sectional design; all the residing patients that met the inclusion criteria were included in the survey. Stool samples were collected and examined by direct wet preparation and formol-ether concentration. Data were analyzed with STATA version 12.1; Chi-square test was computed to determine the level of significance at p value < 0.05.

RESULTS

Of all 233 patients who returned the stool samples, 29 (12.45%) screened were positive for an intestinal parasite. There was no significant association between parasite carriage and age, sex, or duration of hospital stay.

CONCLUSION

The study shows that intestinal parasitic infection is common among patients in a psychiatric facility and highlights that parasitic infections that enter through skin penetration may be a more common mode of transmission than the oral route. Furthermore, the study underscores the need for surveillance and intervention programs to control and manage these infections.

Human infection with Strongyloides stercoralis and other related Strongyloides species

The majority of the 30-100 million people infected with Strongyloides stercoralis, a soil transmitted intestinal nematode, have subclinical (or asymptomatic) infections. These infections are commonly chronic and longstanding because of the autoinfective process associated with its unique life cycle. A change in immune status can increase parasite numbers, leading to hyperinfection syndrome, dissemination, and death if unrecognized. Corticosteroid use and HTLV-1 infection are most commonly associated with the hyperinfection syndrome. Strongyloides adult parasites reside in the small intestine and induce immune responses both local and systemic that remain poorly characterized. Definitive diagnosis of S. stercoralis infection is based on stool examinations for larvae, but newer diagnostics - including new immunoassays and molecular tests - will assume primacy in the next few years. Although good treatment options exist for infection and control of this infection might be possible, S. stercoralis remains largely neglected.

Prevalence of intestinal parasites among patients of a Ghanaian psychiatry hospital

BACKGROUND

Neglected tropical diseases are of major concern to sub-Saharan African countries. Though efforts to monitor the prevalence and control are in place, these are mostly restricted to groups within the population. This study was performed to determine the prevalence among patients of a Ghanaian psychiatric hospital and find out whether there is a reason for active monitoring in this population.

METHODS

A cross-sectional study was performed to determine the prevalence of intestinal parasites among patients of a Ghanaian psychiatric hospital. Stool samples were collected and analyzed in addition to data.

RESULTS

Of the 111 patients studied, asymptomatic carriage of parasites was 13.5 % and was higher in males (18.8 %) than in females (4.8 %). Carriage of parasites decreased with age but increase with duration of admission.

CONCLUSION

This is the first report of parasitic pathogens among patients of a psychiatric institution in Ghana. The data shows that there are risks of transmission of infectious diseases via the oral route hence, the need for regular monitoring and intervention is emphasized.

Prevalence of Strongyloides stercoralis and other intestinal parasitic infections among mentally retarded residents in central institution of southern Iran

OBJECTIVE

To determine the prevalence of intestinal parasitic infections among mentally retarded residents of rehabilitation center of Bandar Abbas, Hormozgan province, southern Iran.

METHODS

A cross-sectional study was carried out in central rehabilitation institute of Hormozgan province in summer 2010. Fecal samples of all 133 residents (72 males, 61 females) aged 3-52, were collected in triplicate. Specimens were examined by direct smear, formalin-ether concentration techniques and stained by permanent Trichrome, Ziehl-Neelsen stains. Statistical analysis was conducted by SPSS 13.5.

RESULTS

Intestinal parasitic infections were seen in 48.5% (64 out of 133 subjects: 53.4% in males and 46.6% in females). Strongyloides stercoralis with 17.3% showed the highest incidence followed by Entamoeba coli (9.8%), Blastocystis hominis (7.5%), Giardia lamblia (2.3%), Endolimax nana (2.3%), Hymenolepis nana (0.8%), Oxyuris vermicularis (0.8%), and Chilomasix mesnili (0.8%). Double infections were found to be as: Strongyloides stercoralis + Giardia lamblia (2.3%), Entamoeba coli + Giardia lamblia (1.5%), Entamoeba coli + Blastocystis hominis (1.5%), Oxyuris vermicularis + Entamoeba coli (0.8%), Strongyloides stercoralis + Entamoeba coli (0.8%), respectively.

CONCLUSIONS

Our findings reveal that strongyloidiasis is a common disease among mentally retarded population in southern Iran.

The Frequency of Enterobius Vermicularis Infections in Patients Diagnosed With Acute Appendicitis in Pakistan

INTRODUCTION

The main aim of this study was to determine the frequency of Enterobius vermicularis infections and other unique histopathological findings in patients diagnosed with acute appendicitis.

MATERIALS

This retrospective study was conducted in a tertiary care hospital of Karachi, Pakistan over a time period of 9 years from 2005 to 2013. The recorded demographic and histopathological data for the 2956 appendectomies performed during this time frame were extracted using a structured template form. Negative and incidental appendectomies were excluded from the study.

RESULTS

Out of the 2956 patients diagnosed with acute appendicitis, 84 (2.8%) patients had Enterobius vermicularis infections. Malignancy (n=2, 0.1%) and infection with Ascaris (n=1, 0.1%) was found very rarely among the patients.Eggs in lumen (n=22, 0.7%), mucinous cystadenoma (n=28, 1.0%), mucocele (n=11, 0.4%), lymphoma (n=9, 0.3%), obstruction in lumen (n=17, 0.6%) and purulent exudate (n=37, 1.3%) were also seldom seen in the histopathological reports.

CONCLUSION

Enterobius vermicularis manifestation is a rare overall but a leading parasitic cause of appendicitis. Steps such as early diagnosis and regular de worming may help eradicate the need for surgeries.

Parasitic infestation in pediatric and adolescent appendicitis: a local experience

OBJECTIVE

The relationship between parasites and pediatric appendicitis is a highly debatable issue. This study aims to investigate the role of parasitic infestation in the etiology of acute pediatric appendicitis.

METHODS

A retrospective study including 1600 pediatric and adolescent patients who had undergone surgical therapy for a diagnosis of acute appendicitis over a period of ten years from Jan 2001 to Dec 2010. Demographic data were retrieved including the patient's age, sex, clinical data, clinical presentations, laboratory investigations, operative data and pathological findings to identify the presence and type of parasites. Patients were divided into two groups according to the presence or absence of parasites in the appendix lumen. In group I (n: 88), parasitic infestation was observed, whereas in group II (n: 1502), no parasitic infestation was present.

RESULTS

Parasites were present in 5.5% (88 patients), and of those 88 parasitic infestations, 45 (51.1%) were Enterobaisis, 8 (9.1%) were Schistosomiasis, 23 (26.1%) were Ascariasis, 7 (8%) Trichuriasis, and 5 (5.7%) were Teania Saginata. The percentage of patients with suppurative, gangrenous or perforated appendicitis was similar in both groups with no statistical significance, irrespective of the presence or absence of parasitic infestation.

CONCLUSION

The low prevalence of parasites among the appendectomy specimens did not support the notion that parasites were a major cause of appendicitis in pediatric patients.

Infections in psychiatric facilities, with an emphasis on outbreaks

Outbreaks of infectious diseases in psychiatric units are very different from those in intensive care units or acute medical-surgical units. Outbreaks in psychiatric units are most often caused by agents circulating in the community. Infection control in psychiatric units also faces unique challenges due to the characteristics of the patients and facilities.

Acute appendicitis secondary to Enterobius vermicularis infection in a middle-aged man: a case report

INTRODUCTION

Acute appendicitis due to Enterobius vermicularis is very rare, affecting mostly children. Whether pinworms cause inflammation of the appendix or just appendiceal colic has been a matter of controversy.

CASE PRESENTATION

A Caucasian 52-year-old man was referred to our Emergency Department with acute abdominal pain in his right lower quadrant. The physical and laboratory examination revealed right iliac fossa tenderness and leukocytosis with neutrophilia. An open appendectomy was performed. The pathological examination showed the lumen containing pinworms. Two oral doses of mebendazole were administered postoperatively. The follow-up to date was without incident and he was free of symptoms one year after the operation.

CONCLUSION

The finding of E. vermicularis in appendectomy pathological specimens is infrequent. Parasitic infections rarely cause acute appendicitis, especially in adults.One should keep in mind that the clinical signs of intestinal parasite infection may mimic acute appendicitis, although rare. A careful evaluation of symptoms such as pruritus ani, or eosinophilia on laboratory examination, could prevent unnecessary appendectomies.

Enterobious vermicularis (pinworm) infestation of the vulva: report of 2 cases of a pseudoneoplastic lesion mimicking squamous carcinoma

Enterobious Vermicularis (pinworm) infestation outside the gastrointestinal tract is rare. We report 2 patients with vulval involvement, one of whom presented with a clinically suspicious, rapidly growing mass. The histology of both lesions showed similar features of epidermal proliferation in the form of hyperkeratosis, acanthosis, and papillomatosis; this pseudoepitheliomatous hyperplasia raised the possibility of a well-differentiated squamous carcinoma. There was associated inflammation in both cases, including large numbers of eosinophils in 1 case. On the surface or within the keratin layer, structures with the morphology of enterobious vermicularis eggs were identified. In reporting this unusual pseudoneoplastic phenomenon, we stress the necessity for the pathologist to consider and look for parasites in proliferative squamous lesions of the vulva, especially when there is an associated inflammatory infiltrate rich in eosinophils.

[Occurrence of enteroparasitosis in carriers of mental disease assisted at São Marcello nursing home in Aracaju, Sergipe State]

The interhuman transmission, low level of personal hygiene, coprophagic habits, among others, may contribute to the dissemination of enteroparasitosis in individuals with mental diseases. The object of this paper was to verify the occurrence of enteroparasitosis in individuals with mental diseases assisted at São Marcello Nursing Home in Aracaju, Sergipe State, in the period between February and May at 2006, and track epidemiological aspects of the transmission. So, coproparasitologic exams were performed, and samples were manipulated by Hoffmann, Pons or Janner (1932) technique. The epidemiological data was obtained from questionnaires applied to the legal responsible for each individual. There were 62.22% of patients infected by at least one parasite. Inadequacies regarding sanitation, habitation and habits of personal hygiene were also observed. This study stressed the importance of a constant monitoring of parasitisms and the continuous observance of the conditions that favor their transmission.

Intestinal parasitic infections among intellectual disability children in rehabilitation centers of northern Iran

Parasitic infection is highly prevalent throughout the developing countries of the world. These infections are the major problem in rehabilitation centers for the mentally retarded. There have been many reports about the prevalence of parasitic infection among different groups of people in Iran; however, the epidemiological data in intellectual disability (ID) individuals are rare and there are no such data from northern Iran. The aim of the present study was to determine the incidence of intestinal parasitic infections among the inhabitants of rehabilitation centers of Mazandaran province, northern Iran. A triple fecal specimens was collected from each of the 362 participants (183 males, 179 females) residing in six rehabilitation centers of Behshahr, Sari, Amol, Nowshahr and Ramsar. Each specimen was examined by direct wet mounting, formol-ether concentration, Ziehl-Neelsen and trichrome permanent staining. The overall infection rate of intestinal parasite was 26.2% (95 out of 362 subjects; 22.4% in males and 30.2% in females). Giardia lamblia was the most commonly found protozoan parasite (8.0%) followed by Entamoeba coli (5.5%), Blastocystis hominis (3.3%), Endolimax nana (2.8%) and Entamoeba histolytica (1.7%). Double infections were E. coli and B. hominis (1.1%), G. lamblia and Chilomastix mesnili (1.1%), G. lamblia and B. hominis (0.5%), G. lamblia and E. coli (0.5%), E. histolytica and E. coli (0.5%), E. nana and E. coli (0.5%) and E. nana and B. hominis (0.5%). No egg-positive case was found. These helminthic parasites were found to be not common among the participants, 75% of whom had been treated with mebendazole by guardians as a tradition, every 6 months. Nevertheless, our data in rehabilitation centers in northern Iran suggest that infection is not higher than that in community population in recent years in this geographical area.

A review and meta-analysis of the impact of intestinal worms on child growth and nutrition

More than a half of the world's population are infected with one or more species of intestinal worms of which the nematodes Ascaris lumbricoides, Trichuris trichiura and the hookworms are the most common and important in terms of child health. This paper: (1) introduces the main species of intestinal worms with particular attention to intestinal nematodes; (2) examines how such worms may affect child growth and nutrition; (3) reviews the biological and epidemiological factors that influence the effects that worms can have on the growth and nutrition of children; (4) considers the many factors that can affect the impact of treatment with anthelmintic drugs; (5) presents the results of a meta-analysis of studies of the effect of treating worm infections on child growth and nutrition; (6) discusses the results in terms of what is reasonable to expect that deworming alone can achieve; (7) describes some important characteristics of an ideal study of the effects of deworming; and (8) comments on the implications for programmes of recommendations concerning mass deworming.

Seroepidemiological aspects of human Strongyloides stercoralis infections in Chile

To determine the frequency of Strongyloides stercoralis antibodies by means of the enzyme linked immunosorbent assay (ELISA) in Chile, in 2001-2003, 675 blood samples of patients of two psychiatric hospitals and 172 of healthy individuals (doctors, nurses and paramedicals) of these institutions, and 1,200 serum samples of blood donors of Northern region (Arica and Antofagasta), Central region (Valparaiso and Santiago) and Southern region (La Union) were collected. ELISA showed positivity of 12.1% in psychiatric hospitalized patients, none (0%) in the health personnel and 0.25% in blood donors (p < 0.05). Only in blood donors of Arica (1%) and La Union (0.5%) the ELISA test was positive suggesting that strongyloidiasis is focalized in determinate zones of the country. In Chile, human infections by S. stercoralis are endemic with very low frequency in apparently healthy individuals and high prevalence in risk groups such as the mentally ill hospitalized patients.

Giardia and Cryptosporidium and public health: the epidemiological scenario from the Italian perspective

Giardia and Cryptosporidium spp. are protozoa that cause human and animal disease worldwide and often exhibit zoonotic transmission. This review gives ample information concerning the epidemiology of these parasites in Italy, i.e. prevalence data in humans, farm and pet animals, shellfish and aquatic environment. Moreover, it reports genotyping results obtained from different isolates, with particular emphasis on the spread of host-specific and zoonotic species/genotypes of various origin, and on molecular data that make the Italian situation different from that of other countries. Finally, possible explanations are given for the infrequent reports of Giardia and Cryptosporidium spp. outbreaks, despite widespread faecal contamination by these parasites.

Eradication of amebiasis in a large institution for adults with mental retardation in Taiwan

OBJECTIVE

Investigation of a program to eradicate amebiasis using consecutive intensive mass screenings followed by medication in a large institute for adults with mental retardation in Taiwan.

DESIGN

Prospective cohort study, with 3 years of follow-up.

SETTING

A large, 450-bed institution for adults with mental retardation located in southern Taiwan.

PARTICIPANTS

All 443 adults with mental retardation in the institution, who have various motor and/or mental handicaps, were included in this study.

INTERVENTIONS

A total of 7 consecutive intensive mass screenings for amebiasis for all residents (performed in March, August and November 2001, March and August 2002, January 2003, and May 2004). Infected patients were treated using the standard protocol of the Center for Disease Control of Taiwan.

RESULTS

Enzyme immunoassay testing was used for the amebiasis screening, with the rapid detection of the specific antigen for Entamoeba histolytica in human fecal specimens confirmed by microscopic examination. The serial prevalence and cumulative incidence were then calculated. The prevalence of amebic infection declined in serial screenings, but new infections and reinfections were detected in 5 of 6 follow-up screenings. The prevalence was 10.8% at the beginning of the program and then gradually reduced, falling to 6.3%, 3.6%, 2.7%, 3.4%, and 2.2%. Finally, no more positive cases were identified in the last screening (May 2004). The cumulative incidence rate stabilized at around 40% by the fifth screening. Of the 179 infected patients, 120 had primary infections, with 59 cases of multiple amebic infections.

CONCLUSIONS

Active surveillance with intensive mass screening is an effective method of identifying asymptomatic and latent cases of amebiasis in areas where it is endemic, such as an institution for adults with mental retardation.

Diversity of clinical isolates of Entamoeba histolytica in Japan

In Japan, amebiasis is domestically transmitted by two major populations: male homosexuals and mentally handicapped persons, which is remarkably different from most other developed countries where Entamoeba dispar infection is predominantly observed. Here we briefly summarize epidemiology of amebiasis in Japan. We also review our current understanding of the diversity of Entamoeba histolytica clinical isolates in Japan, based on polymorphic genetic markers, clinical representations, and in vivo virulence, using an animal model.

Intestinal parasites may not cause nosocomial infections in psychiatric hospitals

This study was conducted to determine whether nosocomial infections of intestinal parasites occur in psychiatric hospitals. Three fecal specimens were collected from each institutionalized patient in seven psychiatric hospitals of north Taiwan. Saline wet mounts were prepared to examine trophozoites, and the other parasite stages were detected using the formalin-ethyl acetate sedimentation technique. Hospital faculties were asked to complete a questionnaire on the demographic data, health status degree of disability, and recent occurrence of gastrointestinal distress of these patients. Of the 464 patients examined, 8.4% were found to be infected with one or more intestinal parasite species: 6.3% single infections, 1.5% double infections, and 0.6% triple infections. Significantly higher prevalences were found among the males, unmarried patients, those with lower education, institutionalized for more than 3 years, sent by social workers to the hospitals, with non-schizophrenic diseases, and with a higher degree of disability. However, only education, marriage, mode of hospitalization, and type of psychiatric disease were found to be significant determinants in a logistic regression model. The variation in prevalence related to demographic factors implies that nosocomial infections may not occur. The mode of hospitalization indicates that the patients may acquire the infections before hospitalization.

Clinical manifestations of appendiceal pinworms in children: an institutional experience and a review of the literature

The association of Enterobius vermicularis infestation with acute appendicitis varies from 0.2-41.8% worldwide. Our purpose was to determine the significance of Enterobius-associated appendicitis by retrospective review of appendectomies performed during a 5-year period at a major children's hospital. The Surgical Pathology database at Children's Hospital, Columbus, Ohio, was reviewed for appendiceal specimens found to have Enterobius infestation. Corresponding patient charts were evaluated for age, gender, presenting symptoms, laboratory data, operative findings, and clinical course. Of the 1,549 appendectomies performed from January 1998 through January 2003, 21 specimens (1.4%) were found to contain Enterobius vermicularis. Fifteen of the appendectomies were performed for symptoms of acute appendicitis; the remaining six were incidental appendectomies in conjunction with other operations. The mean age was 8.9 years. Ten patients were male; 11 were female. Of the 15 symptomatic children, nine presented with fever >99.0 degrees F, and 11 had a WBC count >10,000. Intra-operative appearance of the appendix ranged from normal to perforation. Pathologic evaluation showed neutrophil or eosinophil infiltration in 15 of the 21 specimens. Enterobius infestation is an uncommon cause of acute appendicitis in children in the United States. It may be associated with acute appendicitis, "chronic appendicitis," ruptured appendicitis, or with no significant clinical symptoms.