Objective To investigate epidemic characteristics of a family aggregation COVID-19, and to provide scientific basis for prevention and control of family aggregation epidemic. Methods] Field epidemiological methods were used to investigate the cases and close contacts of a family aggregation COVID-19 in Y County, Chenzhou City, Hunan Province. Descriptive statistical analysis was used on epidemiological data . The 2019-nCoV nucleic acid was detected by real-time fluorescence quantitative RT-PCR. Results It was found that Ms. Deng was infected with COVID-19 and became the infectious source of the family aggregation epidemic , who had lived in Wuhan Hubei Province. Her boyfriend Mr. Cao became a second-generation case of COVID-19..Another two asymptomatic but infected persons were family members living with Ms.Deng . Conclusion COVID-19 easily spreads within families. The awareness of family members' protection, the education of new coronavirus pneumonia prevention and control in key groups should be strengthened to avoid the occurrence and spread of family aggregation epidemic.

OBJECTIVES: To explore the characteristics of immune function of healthy full-term infants at the age of 3 months, and to analyze the relationship of immune function with feeding pattern and sex. METHODS: A total of 84 healthy full-term infants born in four hospitals in Beijing and Hohhot, China were prospectively recruited. Their feeding patterns remained unchanged within 4 months after birth. They were divided into a breast-feeding group and a milk powder feeding group according to their feeding patterns. At the age of 3 months after birth, peripheral venous blood samples of the two groups were collected to evaluate cellular immunity and humoral immunity and perform routine blood test. The laboratory indices were compared between infants with different feeding patterns and sexes. RESULTS: Compared with the milk powder feeding group, the breast-feeding group had significantly lower proportion of T cell second signal receptor CD28, immunoglobulin M, and proportion and absolute count of neutrophils ( CONCLUSIONS Sex has no significant effect on the proportion of lymphocyte subsets in 3-month-old full-term infants, but feeding patterns are associated with the proportion of CD28
Breast Feeding ; CD8-Positive T-Lymphocytes ; Female ; HLA-DR Antigens ; Humans ; Infant ; Lymphocyte Activation ; Male ; Prospective Studies