Sensitivity of candling as routine method for the detection and recovery of ascaridoids in commercial fish fillets.

Ascaridoids are one of the main parasitic hazards in commercial fish. Candling is the current industrial screening method whereby visible ascaridoid larvae are detected on a light table and manually removed. The aim of this study was to assess the sensitivity (Se) and negative predictive value (NPV) of this method. To make targeted recommendations to the fish industry, the Se was calculated per fish part, larval genus, and fish species. All fish parts (n = 615) were first candled, and larvae were collected, followed by enzymatic digestion to recover the remaining larvae. A fish part was considered positive if at least one larva was detected using candling and/or enzymatic digestion, with both methods combined as reference standard. The overall Se of candling was 31% (95% CI 23-41%) and NPV was 87% (95% CI 85-90%). The Se increased with higher numbers of larvae/100 g infected muscle. A low NPV was found for the belly flaps, therefore we either advise the removal or proper freezing of this part. Lastly, the Se and larval recovery was the highest for the darker and larger Pseudoterranova spp. larvae. Due to the low overall efficacy of candling, further assessment of its cost-benefit and impact on consumers' health risk should be conducted.

High occurrence of Anisakidae at retail level in cod (Gadus morhua) belly flaps and the impact of extensive candling.

The presence of Anisakidae at retail level, after the routine screening via candling, was investigated in cod, the most commonly consumed fish species in Belgium. A total of 780 pre-packed belly flap samples destined for one branch of retail shops were collected from a Belgian wholesale company. To recover all larvae, each sample was first candled and thereafter enzymatically digested. Larvae were morphologically identified to the genus level and a subset was additionally molecularly confirmed by amplification of the ITS fragment and HinfI/HhaI enzyme restriction. The PCR/RFLP profiles of Contracaecum spp. were determined and confirmed with sequencing by the European Reference Laboratory for Parasites (Istituto Superiore di Sanità). The positivity rate of Anisakidae in the individual cod samples was 18% [95%-CI: 15-21%], with a mean intensity of one larva [range: 1-6]. Belly flaps were sold packed primarily by two, with a one-in-three chance of buying an infected package. Pseudoterranova spp. infections (single infections) were most frequently detected (positivity rate 9% [95%-CI: 7-11]), closely followed by Anisakis spp. (7% [95%-CI: 6-9]). Co-infections of Pseudoterranova spp. and Anisakis spp. comprised 8% of the infections, with a positivity rate of 1% [95%-CI: 1-3%]. All belly flaps reportedly were candled prior to our sampling, nonetheless our results indicated that an additional candling screening before packaging would identify an extra third of the infections and larvae. In 19 of the 139 infected samples, all larvae were recovered by the additional candling, thereby removing the infection risk for consumers. In conclusion, this study shows that cod belly flaps infected with zoonotic parasites reach the Belgian consumer. Although a second candling step at retail level could be helpful in reducing the consumer risk, additional measures are needed since 66% of infections would still remain undetected.

First case of human Gongylonema pulchrum infection in Slovenia.

Nematodes of the genus Gongylonema infect a wide range of mammals worldwide but are only sporadically reported in humans. We describe a case of human infection with Gongylonema pulchrum in a 41-year-old man. The patient extracted the nematode from the submucosa under his tongue and correctly self-diagnosed the infection with the help of the Google search engine. In the laboratory, the collected nematode was confirmed as G. pulchrum microscopically by morphological analysis and genetically by amplifying and sequencing the parasite's rDNA. This is the first report of human G. pulchrum infection in Slovenia.

Evaluation of rectal swab use for the determination of enteric pathogens: a prospective study of diarrhoea in adults.

OBJECTIVES: A stool sample is the sample of choice for microbiological testing of enteric pathogens causing diarrhoea, but a rectal swab can be a more practical alternative. A prospective observational study was performed to evaluate the diagnostic performance of flocked rectal swab specimens using the syndromic molecular approach to determine the aetiology of diarrhoea in adults. METHODS: We compared the performance of rectal swabs with stool samples as the reference standard in determining viral, bacterial and protozoal pathogens using real-time multiplex PCR as well as standard stool culture. Paired samples of stool and rectal swab specimens were collected from 304 adult patients with diarrhoea, presented at the Department of Infectious Diseases, University Medical Centre Ljubljana, between June 2016 and August 2017. RESULTS: Overall sensitivity of rectal swab samples in the syndromic molecular approach was 83.2% (95% CI 77.2%-88.1%). Pathogen group-specific analysis of rectal swabs showed sensitivity of 65.6% (95% CI 52.7%-77.1%) for viruses and 57.1% (95% CI 28.9%-82.3%) for parasites. For bacteria, sensitivity was 86.5% (95% CI 79.5%-91.8%) when PCR was performed and 61.4% (95% CI 52.4%-69.9%) when culture for bacteria was performed. Mean threshold cycle (Ct) values for most pathogens were higher in rectal swab specimens than in stool specimens. CONCLUSIONS: Our results indicate that rectal swabs can be used in the diagnosis of diarrhoea in adults when stool specimens are not available or when rapid aetiological determination is needed. However, rectal swabs should be analysed using a molecular approach. The mean Ct value for most pathogens is higher in rectal swab specimens than in stool specimens.

Ureaplasma parvum and Ureaplasma urealyticum detected with the same frequency among women with and without symptoms of urogenital tract infection.

There is mounting evidence stating that Ureaplasma urealyticum causes non-gonococcal urethritis in males, whereas Ureaplasma parvum does not seem to be of clinical significance. However, the clinical role of U. parvum and U. urealyticum in lower urogenital tract infections in females remains unclear. The aim of the study was to determine the frequency of U. parvum and U. urealyticum among 145 Ureaplasma spp. culture-positive women with symptoms of lower urogenital tract infection (n = 75) and those without (n = 70), and to determine possible associations between the detection of U. parvum and U. urealyticum with selected characteristics. Endocervical, urethral, and vaginal swabs, and first voided urine were obtained. Polymerase chain reaction (PCR) was performed to differentiate ureaplasmas. No significant association between the detection of U. parvum or U. urealyticum and symptom status was found. Significantly more women aged 25 years and younger were infected with U. urealyticum (23.4 %) compared to those aged above 25 years (9.2 %) [odds ratio (OR) 3.0 (1.1; 8.1); p = 0.03] and significantly less women aged 25 years and younger (83.5 %) were infected with U. parvum compared to those aged above 25 years (95.5 %) [OR 0.2 (0.1; 0.9); p = 0.03]. The detection of Chlamydia trachomatis was significantly associated to both U. parvum and U. urealyticum (p = 0.021), and to U. parvum alone with borderline significance (p = 0.063). Although neither U. parvum nor U. urealyticum seem to cause symptoms in females, their role in the female urogenital tract remains unknown, taking into account their ubiquity, possible augmentation of the urogenital microenvironment, and ascending capability to the sterile upper reproductive tract.

Genetic classification of Cryptosporidium isolates from humans and calves in Slovenia.

To assess the importance of cattle as a source of human cryptosporidial infections in Slovenia, Cryptosporidium isolates from calves and humans with cryptosporidiosis were characterized genetically by direct DNA sequencing, targeting a variable region of the 60 subtypes', were identified, of which 7 were novel. In humans, C. hominis Ia (subtype IaA17R3) and Ib (IbA10G2) and Cryptosporidium parvum IIa (IIaA9G1R1, IIaA11G2R1, IIaA13R1, IIaA14G1R1, IIaA15G1R1, IIaA15G2R1, IIaA16G1R1, IIaA17G1R1 and IIaA19G1R1), IIc (IIcA5G3), and IIl (IIlA16R2) were recorded; this is the first record of the latter subtype in humans. In cattle, C. parvum IIa (IIaA13R1, IIaA15G2R1, IIaA16R1 and IIaA16G1R1) and IIl (IIlA16R2 and IIlA18R2) were recorded. Of the 15 subtypes identified, subtypes of C. parvum IIa were the most frequently encountered (>90%) in both humans and calves. The present findings suggest that zoonotic transmission plays an important role in sporadic human cryptosporidiosis in Slovenia.

Human alveolar echinococcosis in Slovenia.

Between January 2001 and December 2005, 1263 patients suspected of having echinococcosis were screened serologically by indirect haemagglutination assay (IHA). IHA-positive patient sera were then retested by western blot for confirmation and differentiation between Echinococcus granulosus and Echinococcus multilocularis infection. Of 43 sera confirmed as Echinococcus-positive, nine appeared to be specific for alveolar echinococcosis (AE) caused by E. multilocularis. AE-positive serological results corresponded to the clinical and/or imaging findings concerning the patients' liver cysts. The detected incidence of AE was 0.45/10(5) inhabitants, which suggests that clinicians and health authorities in Slovenia should give greater attention to AE in the future.

Molecular characterisation of Cryptosporidium isolates from humans in Slovenia.

Twenty-nine faecal specimens from Slovenian patients in which Cryptosporidium oocysts had been identified were studied. A fragment of the Cryptosporidium 18S rRNA gene and a fragment of the Cryptosporidium COWP gene were amplified by PCR and sequenced. Cryptosporidium parvum was identified in 26 of the 29 specimens, Cryptosporidium hominis in two, and Cryptosporidium cervine genotype in one. The fact that C. parvum, which is associated traditionally with animals, was identified in the majority of human faecal specimens suggests that cryptosporidiosis may have primarily a zoonotic origin in Slovenia.

Seasonal variations in acute toxoplasmosis in pregnant women in Slovenia.

Between December 1999 and December 2004, 40 081 pregnant women were examined for toxoplasmosis with Toxo-IgG, Toxo-IgM enzyme immunoassay. Women with positive results were then retested with the Toxo-IgG avidity assay for recent toxoplasmosis. Recent acute toxoplasmosis in pregnant women was found to be significantly more frequent (p < 0.01) during winter than summer. The incidence of acute toxoplasmosis during winter-spring was also significantly more frequent (p < 0.025) than summer-autumn. This phenomenon should be taken into account when formulating preventive measures for toxoplasmosis, especially for pregnant women.