Larsen O, da Silva Z, Sandström A, Andersen P K, Andersson S, Poulsen A G, Melbye M, Dias F, Nauclér A, Aaby P
Projecto de Saúde de Bandim, Bissau, Guinea-Bissau.
AIDS. 1998 Sep 10;12(13):1707-14. doi: 10.1097/00002030-199813000-00020.
To assess the present level of HIV-2 infection in an adult population in Bissau and to evaluate sex and age-specific changes in HIV-2 prevalence and incidence between 1987 and 1996.
Sex and age-specific changes in HIV-2 prevalence were evaluated comparing a survey from 1987 in a sample of 100 houses with a survey performed in 1996 in an independent sample of 212 houses from the same study area. HIV-2 incidence rates were examined in an adult population (age > or = 15 years) from 100 randomly selected houses followed with four consecutive HIV serosurveys from 1987 to 1996.
The HIV-2 prevalence in 1996 was 6.8% (men, 4.7%; women, 8.4%). Compared with the 1987 survey there was a significant decrease in prevalence among men [age-adjusted relative risk (RR), 0.50; 95% confidence interval (CI), 0.31-0.83], whereas it remained unchanged in women (RR, 1.00; 95% CI, 0.67-1.48). The male-to-female RR decreased from 0.99 (95% CI, 0.61-1.61) in 1987 to 0.51 (95% CI, 0.34-0.76) in 1996. The overall annual incidence rate was 0.54 per 100 person-years of observation (PYO), being higher in women (0.72 per 100 PYO) than in men (0.31 per 100 PYO). With the observation time divided into an early and a late period, there was a decrease in incidence with time among men (0.66 to 0.00 per 100 PYO), but no major change among women (0.59 to 0.85 per 100 PYO). The two trends differed significantly (P = 0.03). We observed a higher annual incidence rate amongst older women aged > 44 years (1.77 per 100 PYO) than among younger women (0.55 per 100 PYO; P = 0.05).
There are no signs of an epidemic spread of HIV-2 in Bissau even though the HIV-1 prevalence is increasing rapidly. A significant reduction in the male HIV-2 prevalence and incidence rates has resulted in a major shift in the pattern of spread of HIV-2, from being equally distributed to being predominantly a female infection. Currently, older women in particular seem to have a high risk of getting infected.
评估比绍成年人群中HIV-2感染的当前水平，并评估1987年至1996年间HIV-2流行率和发病率在性别和年龄方面的变化。
通过比较1987年对100户家庭样本进行的调查与1996年在同一研究区域对212户独立家庭样本进行的调查，评估HIV-2流行率在性别和年龄方面的变化。对1987年至1996年从100户随机选择的家庭中抽取的成年人群（年龄≥15岁）进行连续四次HIV血清学调查，以检查HIV-2发病率。
1996年HIV-2流行率为6.8%（男性为4.7%；女性为8.4%）。与1987年的调查相比，男性的流行率显著下降[年龄调整相对风险（RR）为0.50；95%置信区间（CI）为0.31 - 0.83]，而女性则保持不变（RR为1.00；95%CI为0.67 - 1.48）。男女RR从1987年的0.99（95%CI为0.61 - 1.61）降至1996年的0.51（95%CI为0.34 - 0.76）。总体年发病率为每100人年观察期（PYO）0.54例，女性（每100 PYO为0.72例）高于男性（每100 PYO为0.31例）。将观察时间分为早期和晚期，男性发病率随时间下降（从每100 PYO为0.66例降至0.00例），而女性无重大变化（从每100 PYO为0.59例至0.85例）。这两种趋势差异显著（P = 0.03）。我们观察到年龄大于44岁的老年女性年发病率（每100 PYO为1.77例）高于年轻女性（每100 PYO为0.55例；P = 0.05）。
尽管HIV-1流行率迅速上升，但比绍没有HIV-2流行传播的迹象。男性HIV-2流行率和发病率的显著下降导致了HIV-2传播模式的重大转变，从均匀分布转变为主要是女性感染。目前，特别是老年女性似乎感染风险较高。
