Intestinal protozoa in homosexual men in Edinburgh

Factors and presenting symptoms associated with intestinal spirochaetosis in men who have sex with men: A systematic review

The transmission dynamics and presenting symptoms of intestinal spirochaetosis (Brachyspira pilosicoli, Brachyspira aalborgi) are poorly understood but is seen more frequently in men who have sex with men (MSM) where sexual transmission may occur. We aimed to systemically review the literature to define the factors and presenting symptoms associated with intestinal spirochaetosis in MSM. We systematically searched three bibliographical databases (MEDLINE, EMBASE and Scopus) for manuscripts written in English up to November 2022. The primary author conducted an initial screen and three authors conducted independent reviews to determine the final eligible manuscripts. We only included manuscripts where there were specific data on factors and presenting symptoms associated with intestinal spirochaetosis in MSM. Fifteen manuscripts published between 1981 and 2022 met the inclusion criteria that included 188 MSM. Sexually transmitted intestinal spirochaetosis in MSM was associated with-living with HIV (including having a low CD4 count <200 mm3), having a concomitant sexually transmitted infection, a history of a sexually transmitted infection, co-infection with intestinal parasites; and sexual behaviour including oro-anal sexual contact, oro-genital contact, fisting, condom-less anal sex, receptive anal sex, multiple non-regular sexual partners and increased number of lifetime sexual partners. The presenting symptoms of MSM with intestinal spirochaetosis were diarrhoea, abdominal pain, constitutional symptoms and proctitis, including rectal pain, rectal bleeding rectal discharge, flatulence and tenesmus. We have highlighted some biological and behavioural factors and presenting symptoms associated with intestinal spirochaetosis in MSM which provide insight for clinicians, guidelines and future public health control strategies.

British Association of Sexual Health and HIV (BASHH) United Kingdom national guideline for the management of sexually transmitted enteric infections 2023

This is the first British Association of Sexual Health and HIV (BASHH) national guideline for the management of sexually transmitted enteric infections (STEI). This guideline is primarily aimed for level 3 sexual health clinics; however, it may also be applicable to other settings such as primary care or other hospital departments where individuals with STEI may present. This guideline makes recommendations on testing, management, partner notification and public health control of STEI.

A baseline epidemiological study of the co-infection of enteric protozoans with human immunodeficiency virus among men who have sex with men from Northeast China

Background

Human immunodeficiency virus (HIV) and enteric parasite co-infection not only aggravates the clinical symptoms of parasites but also accelerates acquired immunodeficiency syndrome (AIDS) progression. However, co-infection research on men who have sex with men (MSM), the predominant high-risk population of HIV/AIDS in China, is still limited. In this study, we investigated the epidemiology of enteric parasites, risk factors, and associations with clinical significance in an MSM HIV/AIDS population in Heilongjiang Province, northeast China.

Methods

We recruited 308 MSMs HIV/AIDS patients and 199 HIV-negative individuals in two designated AIDS hospitals in Heilongjiang between April 2016 and July 2017. Fresh stool samples were collected. DNA extraction, molecular identification, and genotyping of Cryptosporidium species, Entamoeba histolytica, Cyclospora cayetanensis, Enterocytozoon bieneusi, and Blastocystis hominis were performed. Fourteen diarrhea-related pathogens were examined to exclude the influence of other bacterial pathogens on diarrhea incidence.

Results

31.5% of MSM HIV/AIDS participants were infected with at least one parasite species, a significantly higher proportion than that found in the HIV-negative individuals (2.5%). E. bieneusi presented the highest prevalence, followed by B. hominis, E. histolytica, Cryptosporidium spp., and C. cayetanensis. Warm seasons were the risk factor for parasitic infections in this population [odds ratio (OR) = 2.6, 95% CI: 1.47–4.57]. In addition, these individuals showed a higher proportion (35.8%) of present diarrhea (PD) compared with men who have sex with women (MSW) with HIV/AIDS (16.7%). The infection proportions of both Cryptosporidium spp. and E. histolytica were significantly higher in the PD. E. bieneusi infection was more prevalent in the historic diarrhea (HD) group. CD4⁺ T cell counts in the MSM patients with the above three parasites were significantly lower. New species and genotypes were found, and MSM patients had a wider range of species or genotypes.

Conclusions

Enteric parasitic infection was prevalent in the MSM HIV/AIDS population, especially in patients with present diarrhea during warm seasons. E. histolytica and B. hominis should also be considered high-risk parasites for opportunistic infections in AIDS patients in addition to Cryptosporidium spp.

Human immunodeficiency virus (HIV) and enteric parasite co-infection not only aggravates the clinical symptoms of parasites but also accelerates acquired immunodeficiency syndrome (AIDS) progression. In China, despite a large number of HIV-infected people, the data regarding co-infection with enteric intracellular parasites in this population is still sparse. In the present study, we investigated the epidemiology of Cryptosporidium spp., Enterocytozoon bieneusi, Blastocystis hominis, Entamoeba histolytica and Cyclospora cayetanensis in 384 HIV/AIDS including 308 MSM HIV/AIDS populations in two designated AIDS hospitals in Heilongjiang Province, North-East China between April 2016 and July 2017 by polymerase chain reaction. We also try to track the possible sources, risk factors, and any associations, with clinical significance, of human parasitic infections. Such knowledge will provide insights into prognosis, treatment, and preventive strategies against infections with such pathogens. The findings in this study have important implications for public health, the control of AIDS progression and control of parasitic infections.

Prevalence and associated risk factors of Giardia infection among indigenous communities in rural Malaysia

This study was carried out to investigate the prevalence and risk factors of Giardia infection among indigenous people in rural Malaysia. Faecal samples were collected from 1,330 participants from seven states of Malaysia and examined by wet mount and formalin-ether sedimentation methods while demographic, socioeconomic and environmental information was collected using a pre-tested questionnaire. The overall prevalence of Giardia infection was 11.6% and was significantly higher among those aged ≤ 12 years compared to their older counterparts. Multivariate logistic regression identified age of ≤12 years, lacking of toilet at household, not washing hands before eating, not washing hands after playing with animals, not boiling water before consumption, bathing in the river, and not wearing shoes when outside as the significant risk factors of Giardia infection among these communities. Based on a multilocus genotyping approach (including tpi, gdh and bg gene sequences), 69 isolates were identified as assemblage A, and 69 as assemblage B. No association between the assemblages and presence of symptoms was found. Providing proper sanitation, as well as provision of clean drinking water and proper health education regarding good personal hygiene practices will help significantly in reducing the prevalence and burden of Giardia infection in these communities.

Co-infection of Sarcina and Giardia in a child

We present a case of 3-year-old boy who presented with vomiting and chronic diarrhoea, and the duodenal biopsy showed the presence of both Giardia and Sarcina. The clinical and pathological significance of Sarcina remains unknown in human beings and its co-existence with Giardia has not been reported.

Sexual transmission of giardiasis: a neglected route of spread?

Sexually transmitted infections (STIs) are often discussed in the context of syphilis, gonorrhea, herpes, chlamydiasis and AIDS. However, since the past 30 years of the last century, epidemiology and natural history studies have led to improved understanding of giardiasis as a STI, as a result of oral-anal sexual contact. Studies suggest that Giardia is an increasingly recognized infection that may be underdiagnosed under the STI context. Health care providers should maintain a high index of suspicion for Giardia, obtain suitable diagnostic tests to identify and screen those at high risk for this infection, institute appropriate therapy, counsel patients regarding treatment compliance, follow-up, encourage partner notification and teach strategies for preventing the transmission of this disease, including the discussion of the risk of enteric infections after oral-anal sexual contact. We summarize some data concerning the research and clinical literature on Giardia infection as a STI and identify the specific recommendations for control of giardiasis as STI that available evidence indicates can reduce its transmission.

A systematic review and meta-analysis of the association between Giardia lamblia and endemic pediatric diarrhea in developing countries

We performed a systematic literature review and meta-analysis examining the association between diarrhea in young children in nonindustrialized settings and Giardia lamblia infection. Eligible were case/control and longitudinal studies that defined the outcome as acute or persistent (>14 days) diarrhea, adjusted for confounders and lasting for at least 1 year. Data on G. lamblia detection (mainly in stools) from diarrhea patients and controls without diarrhea were abstracted. Random effects model meta-analysis obtained pooled odds ratios (ORs) and 95% confidence intervals (CIs). Twelve nonindustrialized-setting acute pediatric diarrhea studies met the meta-analysis inclusion criteria. Random-effects model meta-analysis of combined results (9774 acute diarrhea cases and 8766 controls) yielded a pooled OR of 0.60 (95% CI, .38-.94; P = .03), indicating that G. lamblia was not associated with acute diarrhea. However, limited data suggest that initial Giardia infections in early infancy may be positively associated with diarrhea. Meta-analysis of 5 persistent diarrhea studies showed a pooled OR of 3.18 (95% CI, 1.50-6.76; P < .001), positively linking Giardia with that syndrome. The well-powered Global Enteric Multicenter Study (GEMS) is prospectively addressing the association between G. lamblia infection and diarrhea in children in developing countries.

Characteristics and risk factors for symptomatic Giardia lamblia infections in Germany

BACKGROUND

In developed countries, giardiasis is considered a travel related disease. However, routine surveillance data from Germany indicate that >50% of infections were acquired indigenously. We studied the epidemiological characteristics of symptomatic Giardia infections acquired in Germany and abroad, and verified the proportion of cases acquired in Germany in order to investigate risk factors for sporadic autochthonous Giardia infections.

METHODS

We identified Giardia cases notified by 41 local health authorities between February 2007 and January 2008 and interviewed them on their clinical symptoms, underlying morbidities, travel abroad and potential risk factors for the disease. We conducted a case-control-study including laboratory-confirmed (microscopy or antigen-test) autochthonous Giardia cases with clinical manifestations (diarrhoea, cramps, bloating) and randomly selected controls from the local population registry matched by county of residence and age-group (0-5, 6-19, > or =20 years). Secondary cases, controls with diarrhoea and persons who had travelled outside Germany in the three weeks prior to disease onset (exposure period) were excluded. We calculated adjusted odds ratios (aOR) with 95% confidence intervals (CI) using conditional logistic regression.

RESULTS

Of 273 interviewed cases, 131 (48%) had not travelled abroad during the defined exposure period. Of these 131, 85 (65%) were male, 68 (54%) were living in communities with >100,000 inhabitants and 107 (83%) were aged 20 years or older. We included 120 cases and 240 controls in the case-control study. Cases were more likely to be male (aOR 2.5 CI 1.4-4.4), immunocompromised (aOR 15.3 CI 1.8-127) and daily consumers of green salad (aOR 2.9 CI 1.2-7.2). Contact with animals (pets/farm animals) and exposure to surface water (swimming/water sports) were not associated with symptomatic disease.

CONCLUSIONS

A substantial proportion of Giardia lamblia cases in Germany are indigenously acquired. Symptomatic cases are significantly more likely to be immunocompromised than control persons from the general population. Physicians should consider Giardia infections among patients with no recent history of travel abroad, particularly if they have immune deficiencies. Green salads may be an important vehicle of infection. Information campaigns highlighting this food-borne risk should emphasise the risk to persons with immune deficiencies.

Sexual transmission of intestinal parasites in men who have sex with men

Direct oral-anal sexual contact is a common practice among men who have sex with men (MSM) and is implicated in the transmission of various enteric pathogens including intestinal parasites. The present study reviewed data on the sexual transmission of intestinal parasites among MSM, and highlighted advances in the diagnosis of such infections. The emergence and spread of intestinal parasites is of public health concern particularly in the homosexual community. Intestinal parasitic infection should be considered in the differential diagnosis of gastrointestinal disease in this population. Combination of traditional diagnostic procedures with implementation of testing based on novel molecular methods in the accurate identification of intestinal parasites is important so that early intervention and control of infection is facilitated.

Giardiasis: a pharmacotherapy review

Giardia lamblia, the cause of human giardiasis, is among the most common intestinal protozoa worldwide. Human infection may range from asymptomatic shedding of giardial cysts to symptomatic giardiasis, being responsible for abdominal cramps, nausea, acute or chronic diarrhoea, with malabsorption and failure of children to thrive. At present, treatment options include the nitroimidazoles derivatives; especially metronidazole, which has been the mainstay of treatment for decades and is still widely used. The increasing number of reports of refractory cases with this group of drugs and other antigiardial agents, has raised concern and led to a search for other compounds, some of which have arisen due to the introduction of drugs initially addressed to other diseases. The present article examines some of the most important points of antigiardial pharmacotherapy available at present and the future prospects of development of new agents.

Sexually transmitted proctitis

Sexually transmitted infections such as chlamydia, gonorrhoea, herpes simplex virus and syphilis commonly present with rectal symptoms. Recent outbreaks of lymphogranuloma venereum among homosexual men throughout Europe highlight the need to consider sexually transmitted infections in the differential diagnosis of proctitis. This article examines the causative organisms, clinical features, diagnosis and treatment of sexually transmitted proctitis.

The activity of protease inhibitors against Giardia duodenalis and metronidazole-resistant Trichomonas vaginalis

Antiretroviral protease inhibitors were assessed in vitro for their activity against Giardia duodenalis and Trichomonas vaginalis. Kaletra (a co-formulation of ritonavir and lopinavir) was the most effective overall, with 50% effective drug concentrations (EC(50)) of 1.1-2.7 microM (ritonavir concentration) against G. duodenalis and 6.8-8 microM against metronidazole-sensitive and clinically metronidazole-resistant T. vaginalis. Minimal inhibitory concentrations were 2-2.5 microM and 10-50 microM for G. duodenalis and T. vaginalis, respectively. Within the range of human plasma concentrations for ritonavir, only G. duodenalis was inhibited. Lopinavir alone was less inhibitory than ritonavir but was associated with a blockage in cytokinesis of G. duodenalis trophozoites. Saquinavir was not effective. These findings are significant considering the association between human immunodeficiency virus and T. vaginalis, and between G. duodenalis and homosexual behaviour.