Dandona Lalit, Lakshmi Vemu, Sudha Talasila, Kumar G Anil, Dandona Rakhi
Health Studies Area, Centre for Human Development, Administrative Staff College of India, Hyderabad, India.
BMC Med. 2006 Dec 13;4:31. doi: 10.1186/1741-7015-4-31.
The human immunodeficiency virus (HIV) burden among adults in India is estimated officially by direct extrapolation of annual sentinel surveillance data from public-sector antenatal and sexually transmitted infection (STI) clinics and some high-risk groups. The validity of these extrapolations has not been systematically examined with a large sample population-based study.
We sampled 13838 people, 15-49 years old, from 66 rural and urban clusters using a stratified random method to represent adults in Guntur district in the south Indian state of Andhra Pradesh. We interviewed the sampled participants and obtained dried blood spots from them, and tested blood for HIV antibody, antigen and nucleic acid. We calculated the number of people with HIV in Guntur district based on these data, compared it with the estimate using the sentinel surveillance data and method, and analysed health services use data to understand the differences.
In total, 12617 people (91.2% of the sampled group) gave a blood sample. Adjusted HIV prevalence was 1.72% (95% confidence interval 1.35-2.09%); men 1.74% (1.27-2.21%), women 1.70% (1.36-2.04%); rural 1.64% (1.10-2.18%), urban 1.89% (1.39-2.39%). HIV prevalence was 2.58% and 1.20% in people in the lower and upper halves of a standard of living index (SLI). Of women who had become pregnant during the past 2 years, 21.1% had used antenatal care in large public-sector hospitals participating in sentinel surveillance. There was an over-representation of the lowest SLI quartile (44.7%) in this group, and 3.61% HIV prevalence versus 1.08% in the remaining pregnant women. HIV prevalence was higher in that group even when women were matched for the same SLI half (lower half 4.39%, upper 2.63%) than in the latter (lower 1.06%, upper 1.05%), due to referral of HIV-positive/suspected women by private practitioners to public hospitals. The sentinel surveillance method (HIV prevalence: antenatal clinic 3%, STI clinic 22.8%, female sex workers 12.8%) led to an estimate of 112635 (4.38%) people with HIV, 15-49 years old, in Guntur district, which was 2.5 times the 45942 (1.79%) estimate based on our population-based study.
The official method in India leads to a gross overestimation of the HIV burden in this district due to addition of substantial extra HIV estimates from STI clinics, the common practice of referral of HIV-positive/suspected people to public hospitals, and a preferential use of public hospitals by people in lower socioeconomic strata. India may be overestimating its HIV burden with the currently used official estimation method.
印度官方通过直接外推公共部门产前和性传播感染（STI）诊所以及一些高危人群的年度哨点监测数据，来估计成年人中的人类免疫缺陷病毒（HIV）负担。这些外推的有效性尚未通过基于大样本人群的研究进行系统检验。
我们采用分层随机方法，从印度南部安得拉邦贡图尔区的66个城乡集群中抽取了13838名15至49岁的人，以代表该地区的成年人。我们对抽样参与者进行了访谈，并采集了他们的干血斑，检测血液中的HIV抗体、抗原和核酸。我们根据这些数据计算了贡图尔区的HIV感染者人数，将其与使用哨点监测数据和方法得出的估计值进行比较，并分析卫生服务使用数据以了解差异。
共有12617人（占抽样组的91.2%）提供了血样。校正后的HIV流行率为1.72%（95%置信区间1.35 - 2.09%）；男性为1.74%（1.27 - 2.21%），女性为1.70%（1.36 - 2.04%）；农村为1.64%（1.10 - 2.18%），城市为1.89%（1.39 - 2.39%）。生活水平指数（SLI）下半部分人群的HIV流行率为2.58%，上半部分人群为1.20%。在过去两年中怀孕的妇女中，21.1%在参与哨点监测的大型公共部门医院接受了产前护理。该组中SLI最低四分位数人群的占比过高（44.7%），HIV流行率为3.61%，而其余孕妇的流行率为1.08%。即使将妇女按相同的SLI半部分进行匹配（下半部分4.39%，上半部分2.63%），该组的HIV流行率仍高于后者（下半部分1.06%，上半部分1.05%），这是由于私人执业医生将HIV阳性/疑似妇女转诊至公立医院所致。哨点监测方法（HIV流行率：产前诊所3%，性传播感染诊所22.8%，女性性工作者12.8%）得出贡图尔区15至49岁的HIV感染者估计人数为112635人（4.38%），这是基于我们的人群研究得出的估计值45942人（1.79%）的2.5倍。
由于性传播感染诊所大幅增加了额外的HIV估计数、HIV阳性/疑似患者转诊至公立医院的普遍做法以及社会经济地位较低阶层的人群优先使用公立医院，印度的官方方法导致该地区HIV负担被严重高估。印度目前使用的官方估计方法可能高估了其HIV负担。
