Department of Medicine, University of California, San Diego, La Jolla, California, USA.
Department of Pediatrics, and University of California, San Diego, La Jolla, California, USA.
Breastfeed Med. 2023 Oct;18(10):785-789. doi: 10.1089/bfm.2023.0175. Epub 2023 Sep 21.
Breastfeeding and human milk (HM) improve maternal and infant morbidities and mortality. Therefore, monitoring the safety of breastfeeding and access to HM is of critical importance. In this study, we assessed tools to monitor the presence of monkeypox virus (MPXV) in HM and whether standard Holder pasteurization inactivates MPXV. Heat-inactivated MPXV was added to HM or viral transport media (VTM) and analyzed using both research and clinical MPXV quantitative polymerase chain reaction (qPCR) tests. Infectious MPXV was added to HM and was exposed to 1 cycle of freeze-thaw, incubation for 1 hour at room temperature, or conditions of Holder pasteurization (62.5°C for 30 minutes) followed by infectious unit quantification by plaque assay. Research and clinical nucleic acid tests detect MPXV that was added to HM but with reduced sensitivity compared with equivalent samples in VTM at low virus inoculum. MPXV added to HM to achieve a starting concentration of 225,000 plaque forming units (pfu)/mL remains infectious after freeze-thaw or 1 hour storage at room temperature. However, Holder pasteurization reduced infectious virus below the limit of detection, >2,000-fold reduction in viral titer. MPXV can be detected when added to HM using a clinical laboratory-developed qPCR test without modification, but the detection limit is reduced compared with equivalent samples in VTM. MPXV remains viable in HM should the virus ever gain access to HM, but Holder pasteurization reduces infectious MPXV to below detection limits and can be used to reduce the risk of MPXV transmission to infants who receive pasteurized (donor) HM.
母乳喂养和人乳 (HM) 可改善母婴发病率和死亡率。因此，监测母乳喂养的安全性和人乳的可获得性至关重要。在这项研究中，我们评估了监测人乳中猴痘病毒 (MPXV) 存在的工具，以及标准Holder 巴氏消毒法是否能使 MPXV 失活。 将热灭活的 MPXV 添加到人乳或病毒运输培养基 (VTM) 中，并使用研究和临床 MPXV 定量聚合酶链反应 (qPCR) 检测进行分析。将传染性 MPXV 添加到人乳中，并使其经历 1 个冻融循环、在室温下孵育 1 小时或Holder 巴氏消毒条件（62.5°C 30 分钟），然后通过噬斑测定法对感染性单位进行定量。 研究和临床核酸检测可检测到人乳中添加的 MPXV，但与 VTM 中同等样本相比，灵敏度降低，病毒接种量低。当将 MPXV 添加到人乳中以达到起始浓度为 225,000 噬菌斑形成单位 (pfu)/mL 时，在冻融或室温下储存 1 小时后仍具有感染性。然而，Holder 巴氏消毒法使病毒滴度降低到检测限以下，降低了 >2,000 倍。 使用临床实验室开发的 qPCR 检测无需修改即可检测到人乳中添加的 MPXV，但与 VTM 中的等效样本相比，检测限降低。如果病毒进入人乳，MPXV 仍具有活力，但Holder 巴氏消毒法可将传染性 MPXV 降低到检测限以下，可用于降低接受巴氏消毒（供体）人乳的婴儿感染 MPXV 的风险。
