Objective To study the sequence variation in the env V3-V4 human immunodeficiency virus (HIV)-1 predominant subtype B strains in Hubei Province and to understand the epidemic characteristics and mutations of HIV-1. Methods Epidemiologic survey was done in the HIV-1 carriers in Hubei area. HIV-1 env V3-V4 regions were amplified by nested-polymerase chain reaction (nPCR). The sequences were determined and then phylogenetic analysis was performed. The difference of gene distance were checked by chi square test and the variation of gene distance were descriptively analyzed. Results Four HIV-1 strains or circulating recombinant forms (CRF) were identified in Hubei Province subtype B', B'/C, CRF01_AE and C were 82.69%, 7.69%, 7.69% and 1.92% ,respectively. B' strains were closely related with B. CN. RL 42 from Yunnan Province and B. CN. 02. 02HN from Province Henan, the gene distances were 7.08 ± 2.19 and 7.88 ± 2.28, respectively. Genetic divergence of env of B' strains showed that subtype B' has existed in Hubei area for about 10 years. Amino acid sequence analysis of section env showed V4 was more variable than C3, V3. The top four peptides of V3 loop were GPGR (46.5%), GPGK (30.2%), GPGQ (13.6%) and GQGR (9.3%). Predictions for the potential use of co-receptors on the basis of the critical amino acids within V3 loop disclosed that 16.28% were CCR5-using (R5/NSI), 13.95% were CXCR4-using (X4/SI) while the co-receptor usage of the vast majority (69.77%) could not be predicted. The analysis of glycosylation sites showed that there were 9 sites in env V3-V4 regions of HIV-1 strains in Hubei area and there were deletions in 8 of them, Conclusions Subtype B' is still the main epidemic subtype in Hubei Province and high homologous to the strains from Yunan and Henan Province.

Objective To analyze the global status of COVID-19 epidemics, so as to preliminarily forecast the epidemic trend. Methods The epidemiological data of 208 countries and the prevention and control policies implemented by typical countries from December 31, 2019 to December 14, 2020 were collected. We use the cumulative incidence rate, cumulative mortality, cumulative fatality and real-time dependent reproduction number (R_t) to analyze the epidemic status. We use the provenance package to group different countries and discuss the effect of prevention and control measures. Results As of December 14, 2020, a cumulative incidence of 93.49 per 10000, a cumulative mortality rate of 0.21‰, and a cumulative fatality rate of 3.1‰ had been reported globally.112 of the 208 countries still had R_t ≥ 1.0, and 96 countries had R_t <1.0. The grouping of 208 countries showed that countries from the same continent often gather together and were geographically adjacent. Countries that were geographically adjacent could easily be grouped together. Conclusion As of December 14, 2020, the epidemic situation in most countries had not been effectively controlled, and epidemic prevention and control are facing greater pressure. Sub-Saharan countries currently had a high R_t , and the government had adopted more relaxed epidemic prevention measures. The epidemic situation in this region may continue to deteriorate, and needs to be focused in the later period.