[Estimation on the HIV-1 incidence in Liangshan Yi Autonomous Prefecture, under BED-capture enzyme immunoassay, from 2011 to 2013]

OBJECTIVE

This paper aimed to analyze the situation of HIV infection in Liangshan Yi Autonomous, including HIV recent rate of infection and the ongoing strategies on prevention of the disease in this prefecture.

METHODS

Surveillance data on population size, medical institutions, from 2011 to 2013 in Liangshan prefecture was collected. The total numbers of people living in the areas appeared as 412 608, 393 699 and 443 025 from the above mentioned three years. The overall numbers of people living with HIV/AIDS were 4 480, 3 999 and 4 719 respectively in the three years of observation, using the ELISA and WB blot. We also used the ELISA, and Western blotting methods to find out the HIV-positive individuals. We then applied the ' BED HIV-1 incidence capture enzyme immunoassay (BED-CEIA)' on these HIV-positive individuals to locate those who were recently infected, to estimate the annual recent infection rates.

RESULTS

The HIV-positive rates in Liangshan Prefecture appeared as 1.09%, 1.02% and 1.07% respectively, from 2011 to 2013, with the recent infection rates as 0.34% (95%CI: 0.32-0.37), 0.62% (95%CI: 0.58-0.66) and 0.61% (95%CI: 0.57-0.65) respectively. The newly infections mainly involved with males, with Yi ethnicity, married, being illiterate or received primary school education. In males, the rates of infection appeared as 64.24% (433/674), 59.22% (504/851) and 58.37% (495/848) respectively, in the three years of observation among people with Yi ethnicity, the recent infection rates were 84.72% (571/674) in 2011, 94.59% (805/851) in 2012 and 84.20% (714/848) in 2013. The rates seen in married people were 61.57% (415/674), 61.45% (523/851) and 60.50% (513/848) respectively. Among the illiterates or people only received primary school education, the rates appeared as 60.24% (406/674) in 2011, 61.57% (524/851) in 2012, and 60.03% (509/848) in 2013.

CONCLUSION

Using the HIV recent infection rate to describe the situation of AIDS in Liangshan prefecture, figures seemed to be more reliable than under the regular HIV-positive rate.

[Development of a new system for selection of A. foetidus transformed with foreign genes by using thymidine kinase gene as a marker and expression of HBsAg gene in A. foetidus]

A new system for selection of transformed Aspergillus foetidus was reported. In this system, TK- A. foetidus which were constructed by homologous recombination of mutated TK gene of vaccinia virus with TK gene of A. foetidus were screened by adding BUdR in agar plates. Conditions for screen of TK+ A. foetidus strain, transformation of A. foetidus and selection of transformed TK- A. foetidus have been studied. By using this system, several transformed A. foetidus which contained HBsAg gene derived bf a promoter H8 cloned from genomic DNA of A. foetidus were isolated. It was demonstrated that HBsAg gene was integrated into the chromosome DNA of A. foetidus by Southern blot after many passages of spores. ELISA showed that HBsAg was positive in the growth medium (p/n = 20). The 22 nm particles which were very similar to the HBsAg particles in human serum were found in the growth medium by immunoelectromicroscope. Western blot also gave the specific bands. All these data showed that HBsAg gene was expressed in A. foetidus and the products were secreted into the growth medium. The selection system using TK gene as marker could generally be used to study the expression of foreign gene in A. foetidus.