A specification of a population leading to an HIV epidemic in the Philippines, and modeling of the entry sites and the resultant circulation routes of foreign HIV strains into and in the country.

对艾滋病毒感染的监测对于预防疫情暴发非常重要。然而，仅通过艾滋病毒监测很难确定流行病的早期阶段，因此我们增加了对丙型肝炎病毒（HCV）的监测，以作为血源性IIN感染的替代标志物。血液传播的艾滋病毒感染被认为是在性接触相关感染之前爆发的初始阶段的传播措施。在菲律宾的吕宋岛、维萨亚岛和棉兰老岛组织了监测区，共检测了2,645个样本，其中包括来自注射吸毒者的1,494个样本。很少检测到艾滋病毒，这支持了菲律宾艾滋病毒感染率低的原因。然而，血液传播的HCV感染在注射吸毒者和透析患者中普遍存在。宿雾市区（维萨亚中心）注射吸毒者中HCV感染率为8936%，HIV感染率较低，为0.40%。在菲律宾首都马尼拉（菲律宾吕宋岛中心）流行的HCV毒株种类最多，亚型1b、基因型4和基因型6仅在马尼拉可见，部分毒株与外源毒株的同源性高于马尼拉市流行毒株。菌株的多样性可能表明外来菌株可能优先进入马尼拉大都会而不是其他地区。在三个地区（如上图所示）收集的一些毒株在系统发生树中混合在一起，表明丙型肝炎病毒可能在菲律宾迅速传播。HCV研究结果表明，WV可能进入马尼拉大都会，并在菲律宾其他地区传播。

The monitoring of an HIV infection is important for the prevention of an outbreak. However, it is difficult to identify the early phase of an epidemic only by HIV monitoring and we add the monitoring of Hepatitis C virus (HCV) to be used for a surrogate marker of blood-borne IIN infection. Blood-borne HIV infections have been considered to be the spread measures at initial phase of an outbreak before sexual contact-related infections.Surveillance areas have been organized in Luzon, Visaya, and Mindanao in the Philippines, and totally 2,645 samples have been tested including 1,494 ones from injecting drug users (IDUs). HIV has been rarely detected, which supports the low prevalence of HIV infection in the Philippines. However, the blood-borne HCV infections are prevalent among IDUs and dialysis patients. The percentage of HCV infections among IDUs at downtown in Metro Cebu (the center of Visaya) were 8936 although that of HIV was few, 0.40%. The profiles of HCV indicated that the variety of the strains prevalent in Metro Manila (capital of the Philippines and the center of Luzon) has been biggest Subtype-1b, genotype-4 and 6 were only observed in Metro Manila Moreover, some of them strains bad higher homology to foreign strains than those prevalent in Metro Manila. The strains variety may indicate that the foreign strains may preferentially enter into Metro Manila than other areas. Some strains collected in three areas (shown above) mixed together in the Phylogenetic trees, suggesting HCV stains may circulate quickly in the Philippines.The results of HCV study indicate that WV may enter into Metro Manila and circulate into other area in the Philippines.