Strongyloides stercoralis infection: an underlying cause of invasive bacterial infections of enteric origin. Results from a prospective cross-sectional study of a northern Italian tertiary hospital.

PURPOSE OF THE STUDY: We assessed the prevalence of S. stercoralis in a cohort of inpatients with invasive bacterial infections of enteric origin to investigate whether the parasite may facilitate these bacterial infections even in the absence of larval hyperproliferation. METHODS: We performed a prospective cross-sectional study in a hospital in northern Italy. Subjects admitted due to invasive bacterial infection of enteric origin and potential previous exposure to S. stercoralis were systematically enrolled over a period of 10 months. S. stercoralis infection was investigated with an in-house PCR on a single stool sample and with at least one serological method (in-house IFAT and/or ELISA Bordier). Univariate, bi-variate and logistic regression analyses were performed. RESULTS: Strongyloidiasis was diagnosed in 14/57 patients (24.6%; 95% confidence interval 14.1-37.8%) of which 10 were Italians (10/49, 20.4%) and 4 were migrants (4/8, 50.0%). Stool PCR was performed in 43/57 patients (75.4%) and no positive results were obtained. Strongyloidiasis was found to be significantly associated (p ≤ 0.05) with male gender, long international travels to areas at higher endemicity, deep extra-intestinal infectious localization and solid tumors. In the logistic regression model, increased risk remained for the variables deep extra-intestinal infectious localization and oncologic malignancy. CONCLUSIONS: Our findings suggest a new role of chronic strongyloidiasis in favoring invasive bacterial infections of enteric origin even in the absence of evident larval dissemination outside the intestinal lumen. Further well-designed studies should be conducted to confirm our results, and possibly establish the underlying mechanisms.

First Italian report of a liver abscess and metastatic endogenous endophthalmitis caused by ST-23 hypervirulent Klebsiella pneumoniae in an immunocompetent individual.

BACKGROUND: Klebsiella pneumoniae is a common species in the gut of mammals and is widely distributed in the environment. However, the environmental source of hvKp that precedes gut colonization is unclear, but once that it reaches the gut there is a possible generalized spread y fecal-oral transmission especially in endemic areas. Liver abscess might develop when the bacteria, using its virulence factors, cross the intestinal barrier and invade the liver by the portal circulation. This syndrome, prevalent mostly in Asian countries, is increasingly reported in Western Countries and leaves open questions about the source of infection. CASE: Here we describe for the first time in Italy, a case of pyogenic liver abscess caused by a hypervirulent Klebsiella pneumoniae (HvKp) complicated by endophthalmitis and other metastatic infections in lung and prostate in an immunocompetent Chinese healthy individual with no recent travel in Asia. CONCLUSION: This case underlines the need for increased awareness of hypervirulent K. pneumoniae, even in settings where it occurs infrequently and where there are not evident epidemiological links.

Management of Invasive Infections due to a Rare Arthroconidial Yeast, Saprochaete capitata, in Two Patients with Acute Hematological Malignancies.

Saprochaete capitata is an arthroconidial yeast, found principally in the environment, even if it belongs also to the normal microbial flora that colonize human subjects. This yeast is increasingly associated with invasive infections in hematological patients, in particular in those affected by acute leukemia. An important risk factor that predisposes to this infection is the profound neutropenia present in such immunocompromised patients. Saprochaete spp. were found resistant to both echinocandins and fluconazole so the treatment is often difficult. Here, we report two cases of sepsis in two patients with acute leukemia. All of them had fatal events, due to the worsening of their clinical condition. An early diagnosis and appropriate management of these pathogens is important in consideration of the poor prognosis associated to these fungal invasive infections.

Detection and molecular characterization of enteric viruses in children with acute gastroenteritis in Northern Italy.

Enteric viral infections are a major concern for public health, and viral acute gastroenteritis is the principal cause of pediatric morbidity and mortality worldwide, mostly in developing countries. The purpose of this study was to determine the prevalence of different enteric viruses detected in a pediatric population with acute gastroenteritis symptoms, and to characterize the strains detected. Stools were collected from children, aged from 2 months to 15 years old, admitted to one of the main hospitals of Northern Italy, between November 2015 and October 2016. Stools were tested for nine enteric viruses (adenovirus, rotavirus A, norovirus, astrovirus, sapovirus, enterovirus, parechovirus, bocavirus and aichivirus) by molecular methods. Furthermore, rotavirus, norovirus and adenovirus were deeply characterized by nucleotide sequencing and phylogenetic analysis. A total of 151 out of 510 (29.6%) stools analyzed resulted positive for at least one of the enteric virus investigated. The most common virus detected was rotavirus A (53/151, 35.1%), followed by norovirus (39/151, 25.8%), adenovirus (35/151, 23.1%), sapovirus (9/151, 6%), enterovirus (5/151, 3.3%), astrovirus (5/151, 3.3%), parechovirus (4/151, 2.6%) and bocavirus (1/151, 0.6%). Aichi virus was not detected in any sample. Co-infections were detected in 12 out of 510 faecal samples (2.3%). These data improved the knowledge of the enteric viruses circulating in children in Northern Italy. In fact, besides rotavirus, adenovirus and norovirus, several viruses circulated across the whole year in the pediatric population object of this study. The introduction of specific viral diagnosis in our clinical setting will improve patient care by reducing unnecessary use of antibiotics addressing the right etiologic diagnosis.

Nosocomial outbreak of the pandemic Influenza A (H1N1) 2009 in critical hematologic patients during seasonal influenza 2010-2011: detection of oseltamivir resistant variant viruses.

BACKGROUND: The pandemic influenza A (H1N1) 2009 (H1N1pdm09) virus infection caused illness and death among people worldwide, particularly in hematologic/oncologic patients because influenza infected individuals can shed virus for prolonged periods, thus increasing the chances for the development of drug-resistant strains such as oseltamivir-resistant (OST-r) variant. METHODS: The aim of our study was to retrospectively evaluate the clinical importance of OST-r variant in circulating strains of the pandemic H1N1pdm09 virus. By means of RT-PCR and Sanger sequencing we analysed the presence of OST-r variant in 76 H1N1pdm09 laboratory-confirmed cases, hospitalized at the hematologic/oncologic ward at Spedali Civili of Brescia -Italy. RESULTS: Out of 76 hospitalized hematologic/oncologic patients, 23 patients (30.2%) were infected by H1N1pdm09 virus. Further investigation revealed that 3 patients were positive for the OST-r variant carrying the H275Y mutation. All the 23 infected patients were immuno-compromised, and were under treatment or had been treated previously with oseltamivir. Three patients died (13%) after admission to intensive care unit and only one of them developed H275Y mutation. CONCLUSIONS: Our retrospective observational study shows that pandemic influenza A (H1N1) 2009 virus can cause significant morbidity and even mortality in hematologic/oncologic patients and confirms the high rate of nosocomial transmission of pandemic H1N1pdm09 virus in these critical subjects. Indeed, the reduction in host defences in these hospitalized patients favoured the prolonged use of antiviral therapy and permitted the development of OST-r strain. Strategies as diagnostic vigilance, early isolation of patients and seasonal influenza A(H1N1) vaccination may prevent transmission of influenza in high risk individuals.