Evidence for re-infection and persistent carriage of Shigella species in adult males reporting domestically acquired infection in England.

OBJECTIVES: We analysed national surveillance typing data of Shigella isolated from adult males with domestically acquired infection (a cohort largely consisting of men who have sex with men (MSM)) to establish whether multiple isolates from the same individual over time represented persistent carriage or re-infection. METHODS: We carried out a retrospective cohort study of adult males diagnosed with Shigella from 2004 to 2018. Median time intervals between multiple isolations of Shigella flexneri and S. sonnei were compared. Analysis of whole genome sequencing data provided strain discrimination at the single nucleotide level and was used to quantify the genetic distance among isolates. Maximum likelihood phylogenies were constructed to determine whether persistent carriage (characterized by multiple isolations of the same strain) or re-infection (characterized by multiple isolations of different strains) was best supported by the phylogenetic analysis. A comparison analysis was carried out using data linked to adult females with domestically acquired shigellosis. RESULTS: The number of men reporting multiple isolations of Shigella species was 165/4733 (3.5%) compared with 31/2423 (1.3%) females (p < 0.001). For isolate pairs from men associated with persistent carriage, the isolation time interval range was 6-176 days (median 23.5; IQR 8-70) and single nucleotide polymorphism (SNP) distance range was 0-7 SNPs (median 0.5; IQR 0-2). For those associated with re-infection, the isolation time interval was 34-2636 days (median 732; IQR 191-1258) and the SNP distance was 10-1462 SNPs (median 120; IQR 29-377). DISCUSSION: Multiple Shigella isolations in individuals with domestically acquired infections was more frequently observed in adult males than in adult females. Following the acute phase of infection, carriage can persist for months, and infection can recur within months, even with strains belonging to the same species and the same serotype. A combination of multiple sexual partners, persistent carriage following the acute phase of infection and evidence of recurrent re-infection is likely to contribute to sustained transmission in this population.

Distribution and risk factors of Trichomonas vaginalis infection in England: an epidemiological study using electronic health records from sexually transmitted infection clinics, 2009-2011.

We used data from the Genitourinary Medicine Clinic Activity Dataset (GUMCAD) over a 3-year period (2009-2011) to investigate the distribution and risk factors of Trichomonas vaginalis infection in England. Socio-demographic and clinical risk factors associated with a diagnosis of T. vaginalis were explored using multivariable logistic regression. Rates of T. vaginalis infection were highest in London and the West Midlands. For men and women, T. vaginalis infection was significantly associated with: older age compared to those aged 20-24 years, non-white ethnicity (in particular black Caribbean and black 'other' ethnic groups), and birth in the Caribbean vs. birth in the UK. Current gonorrhoea or chlamydia infection was associated with a diagnosis of T. vaginalis in women. Further research is required to assess the public health impact and cost-effectiveness of introducing targeted screening for women at high risk of infection in areas of higher prevalence.

High levels of hCG in choriocarcinoma can result in renal failure and a false-negative pregnancy test in men.

The diagnosis of choriocarcinoma was delayed because a urinary pregnancy test for hCG was falsely negative. This man's hCG rose to 25,000,000 iu/l. He developed renal impairment, probably due to precipitation of hCG in his renal rubules.

Serial measurements of Ca antigen in sera from patients with advanced malignant breast disease.

Ca antigen levels in serum samples from three groups of patients were assayed. From a survey of 173 patients with various malignancies, elevated levels were found most consistently in patients with metastatic breast cancer. Spearman rank correlation values of Ca and CEA values on individual serum samples, 0.3009, (n = 194), or individual and serial samples, 0.2406, (n = 264) from a total 194 patients with metastatic breast cancer showed that correlation between Ca and CEA values was poor. For a group of 20 patients within the 194, from whom fortnightly serial samples were available, serum levels for 10/20, measured retrospectively, corroborated clinical observations on the course of their disease, although only 4/20 showed marked elevations during active disease. No correlations between expression of the tumour marker and histological type of the primary tumour, age of the patient, site of recurrence nor aberrant elevation in response to cytotoxic drug could be found to explain the non-correspondence of marker behaviour and disease status in the remaining 10 patients. The indications from this small study are that serial Ca antigen serum measurement could be misleading in 50% of patients with metastatic breast cancer, and that the assay is unsuitable for follow-up of patients with breast cancer.

Carcinoembryonic antigen levels in germ cell tumours.

Elevated serum carcinoembryonic antigen (CEA) prior to specific treatment was noted in 3% (7/258) of assessable patients with testicular, extragonadal or ovarian germ cell tumours (GCT). In addition, persistently raised CEA was documented in 7% (26/385) of patients during or after cisplatin-based chemotherapy for metastatic GCT. Raised CEA did not appear associated with adverse prognosis. Among patients undergoing resection of residual tumour masses post-chemotherapy, 8 of 36 with mature differentiated teratoma excised had raised CEA compared with only one of 39 patients where no mature teratoma was found. However, CEA levels remained elevated in 6 of the 8 cases despite apparent complete resection of mature teratoma. Elevated CEA in treated GCT patients may be caused by hepatotoxicity from chemotherapy, intercurrent diseases, or other unknown factors. History of cisplatin-based chemotherapy may be a confounding factor in interpreting raised CEA levels. CEA measurements do not help in the management of patients with germ cell tumours.

A multi-center evaluation of a new immunoenzymometric assay for human choriogonadotropin.

A new, rapid, monoclonal immunoenzymometric assay for human choriogonadotropin (HCG), the Enzymun-Test HCG (Boehringer Mannheim GmbH), was evaluated by 15 laboratories in 10 European countries. Inter-assay percent CVs ranged from 5.4 to 40.5, 2.4 to 15.4, and 2.3 to 17.1 for low, medium, and high dose sera, respectively. Mean assay sensitivity was 0.34 mIU/mL HCG. Analytical recovery in serum ranged from 75 to 119%. Serial dilutions of HCG in normal human serum and in assay zero standard were found to be linear. Cross-reactivity with lutropin, follitropin, and thyrotropin was negligible. Serum reference values were established for normals and all stages of pregnancy. Comparative studies with nine other HCG immunoassays were carried out using a range of normal, pregnancy, and tumour sera. We conclude that this is an acceptable assay for monitoring HCG-producing tumours and pregnancy.

Radioimmunolocalization and selection for surgery in recurrent colorectal cancer.

The value of radioimmunolocalization (RIL) of cancer depends on its performance in situations where the result determines the choice of management. A rise in serum carcinoembryonic antigen (CEA) values after apparently curative resection of colorectal cancer implies localized, resectable recurrence in some patients and widespread unresectable tumour in others. This study investigated the ability of RIL with radiolabelled antibody to CEA and a novel numerical method for analysis of results to determine the extent of disease in 31 patients with raised serum CEA but no physical signs of recurrence. Surgical exploration or conventional radiology later confirmed the presence of tumour in 94 per cent of sites which were positive by RIL. Negative RIL predicted the absence of disease in 53 per cent of patients. The investigation could discriminate between localized and disseminated disease and often performed better than conventional radiology. RIL appears useful in selection of patients for second look laparotomy.