Detection of Zika virus in mouse mammary gland and breast milk

Clinical reports of Zika Virus (ZIKV) RNA detection in breast milk have been described, but evidence conflicts as to whether this RNA represents infectious virus. We infected post-parturient AG129 murine dams deficient in type I and II interferon receptors with ZIKV. ZIKV RNA was detected in pup stomach milk clots (SMC) as early as 1 day post maternal infection (dpi) and persisted as late as 7 dpi. In mammary tissues, ZIKV replication was demonstrated by immunohistochemistry in multiple cell types including cells morphologically consistent with myoepithelial cells. No mastitis was seen histopathologically. In the SMC and tissues of the nursing pups, no infectious virus was detected via focus forming assay. However, serial passages of fresh milk supernatant yielded infectious virus, and immunohistochemistry showed ZIKV replication protein associated with degraded cells in SMC. These results suggest that breast milk may contain infectious ZIKV. However, breast milk transmission (BMT) does not occur in this mouse strain that is highly sensitive to ZIKV infection. These results suggest a low risk for breast milk transmission of ZIKV, and provide a platform for investigating ZIKV entry into milk and mechanisms which may prevent or permit BMT.

Prototype breast coil for MR-guided needle localization

OBJECTIVE

Evaluation of breast lesions detected by MR alone is a problem: Preoperative MR-guided localization is difficult, since the breast is not accessible by a needle within the breast coil. Magnetic resonance-guided core biopsy and needle aspiration are impossible. Together with Siemens Erlangen, a prototype localization breast coil has been developed and tested.

MATERIALS AND METHODS

The device consists of a circular polarized coil, which contains two plates for mediolateral breast compression. They are perforated with numerous holes and thus allow access to the breast from both sides. By means of bushings, which fit into the holes, sterile needle insertion in a horizontal path is possible.

RESULTS

So far, precise needle insertion has been possible in 10 of 11 lesions, allowing exact needle insertion into 5 invasive carcinomas (1 MR-detected), 1 MR-detected additional focus, 2 in situ carcinomas (1 MR-detected), and 3 benign lesions.

CONCLUSION

Our studies show that MR-guided needle localization is possible.