Transmission of H7N9 influenza virus in mice by different infective routes

BACKGROUND: On 19 February 2013, the first patient infected with a novel influenza A H7N9 virus from an avian source showed symptoms of sickness. More than 349 laboratory-confirmed cases and 109 deaths have been reported in mainland China since then. Laboratory-confirmed, human-to-human H7N9 virus transmission has not been documented between individuals having close contact; however, this transmission route could not be excluded for three families. To control the spread of the avian influenza H7N9 virus, we must better understand its pathogenesis, transmissibility, and transmission routes in mammals. Studies have shown that this particular virus is transmitted by aerosols among ferrets. METHODS: To study potential transmission routes in animals with direct or close contact to other animals, we investigated these factors in a murine model. RESULTS: Viable H7N9 avian influenza virus was detected in the upper and lower respiratory tracts, intestine, and brain of model mice. The virus was transmissible between mice in close contact, with a higher concentration of virus found in pharyngeal and ocular secretions, and feces. All these biological materials were contagious for naïve mice. CONCLUSIONS: Our results suggest that the possible transmission routes for the H7N9 influenza virus were through mucosal secretions and feces. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1743-422X-11-185) contains supplementary material, which is available to authorized users

Fetal liver iron overload: The role of MR imaging

Objective: To assess the potential role of MR imaging in the diagnosis of fetal liver iron overload. Methods: We reviewed seven cases of abnormal liver signal in fetuses referred to MR imaging in a context of suspected congenital infection (n∈=∈2), digestive tract anomalies (n∈=∈3) and hydrops fetalis (n∈=∈2). The average GA of the fetuses was 31 weeks. The antenatal diagnoses were compared with histological data (n∈=∈6) and postnatal work-up (n∈=∈1). Results: Magnetic resonance imaging demonstrated unexpected abnormal fetal liver signal suggestive of iron overload in all cases. The iron overload was confirmed on postnatal biopsy (n∈=∈2) and fetopathology (n∈=∈4). The final diagnosis was hepatic hemosiderosis (haemolytic anaemia (n∈=∈2) and syndromal anomalies (n∈=∈2)) and congenital haemochromatosis (n∈=∈3). In all cases, the liver appeared normal on US. Conclusions: Magnetic resonance is the only imaging technique able to demonstrate liver iron overload in utero. Yet, the study outlines the fundamental role of MR imaging in cases of congenital haemochromatosis. The antenatal diagnosis of such a condition may prompt ante-(in the case of recurrence) or neonatal treatment, which might improve the prognosis. © 2010 European Society of Radiology.SCOPUS: ar.jinfo:eu-repo/semantics/publishe