巴基斯坦的脊髓灰质炎.doc

巴基斯坦的脊髓灰质炎 巴基斯坦的脊髓灰质炎2011年7月7日- 巴基斯坦报告称，在发生冲突、难以进入的联邦管辖部落地区（FATA）开伯尔特区，从一名16个月龄的幼儿体内分离出野生3型脊灰病毒（WPV3），该名幼儿于2011年6月9日出现麻痹。这是2011年在亚洲发现的唯一一例野生3型脊灰病毒病例。野生3型脊灰病毒在亚洲的传播处于即将被消除的边缘阶段，上一病例的发现还是6个多月前，发生在2010年11月18日（同样也来自联邦管辖的部落地区，开伯尔特区）。 确认出现野生3型脊灰病毒在巴基斯坦部落地区的持续传播，严重影响了全球消灭野生3型脊灰病毒，特别是对于即将消除这一毒株流行的亚洲而言。在巴基斯坦发现野生3型脊灰病毒，意味着这一危险可能会从这一传播源蔓延到亚洲无野生3型脊灰病毒的其他地区，甚至会到更远的地方。在全球范围内，野生3型脊灰病毒的传播在2011年达到历史低点，该毒株在其他地方的流行局限在西非部分地区（科特迪瓦、几内亚、马里和尼日尔共有17例）、尼日利亚（5例）和乍得（3例）。世界卫生组织（世卫组织）认为，野生3型脊灰病毒出现进一步传播的风险很高，特别是考虑到巴基斯坦境内以及巴基斯坦与阿富汗之间的大规模人口流动，以及未来几个月内，可以预料的因小朝和即将到来的麦加朝圣而引发的大规模人口流动（到沙特阿拉伯王国的麦加朝圣）。2011年，巴基斯坦在高风险地区开展的补充免疫活动（SIAs）的质量较低，同时，生活在受冲突影响部落地区的很大比例儿童仍无法获得免疫接种。在联邦管辖的部落地区，特别是在开伯尔特区，过去两年中，补充免疫活动通常都会遗漏近50%的儿童。除了在开伯尔普赫图赫瓦及联邦管辖部落地区的不安全区域存在接触儿童方面的相关挑战外，补充免疫活动的质量也因为开伯尔可进入区域及该国其他主要传播区域遇到的重大业务挑战而持续受到损害，特别是在俾路支省和信德省。除2011年在亚洲确认的唯一一例野生3型脊灰病毒病例外，巴基斯坦仍然受到野生1型脊灰病毒的全国性地域传播带来的影响，与2010年同期出现的14例野生1型脊灰病毒病例相比，2011年已确诊57例野生1型脊灰病毒病例（截至2011年7月5日）。为紧急处理这一状况，在总统阁下的支持下，巴基斯坦政府已于今年启动了国家脊灰紧急行动计划。应世界卫生大会要求，该国于2010年设立了独立监督委员会，以独立监督无脊髓灰质炎世界的进展情况。然而，该委员会于2011年4月发出警报，指出该计划的执行所花时间太长，2011年6月东地中海技术咨询小组的结论亦与此相一致。 为迅速加强对这两种脊灰病毒毒株的免疫力，目前开伯尔特区正在开展双价口服脊髓灰质炎疫苗短时间间隔追加剂量策略（SIAD）的补充免疫活动，7月4日为第一阶段，7月12日为第二阶段。预计，在6月中旬开展的最近一次补充免疫活动中，短时间间隔追加剂量策略仍然无法覆盖开伯尔特区45%（89449）的目标儿童（Bara Tehsil占80%，约73000人）。使用双价口服脊髓灰质炎疫苗的（包含1型和3型血清型）国家免疫接种日（NIDs）将于7月18-20日在该国开展。但成功的关键是要解决完全可进入地区存在的其余业务挑战并实行特别外展战略，使社区完全参与进来，以提高安全欠佳地区人口的可及性。为尽量降低野生3型脊灰病毒再次波及阿富汗的风险，同样使用双价口服脊髓灰质炎疫苗的次国家级免疫接种日（SNIDs）活动包括与巴基斯坦的搭界地区将于7月10-12日在该国开展。重要的一点是，亚洲和东地中海各国应加强对急性弛缓性麻痹（AFP）的疾病监测，以便能够迅速发现脊灰病毒输入情况，并在出现输入时促进作出快速应对。各国也应当继续扩大针对所有脊灰病毒毒株的常规免疫覆盖面，尽量降低病毒输入造成的后果。按照世卫组织国际旅行和健康所述建议，来往巴基斯坦的旅客应当受到免疫接种的完全保护。去往巴基斯坦的旅客如果在过去服用过3剂或3剂以上的口服脊髓灰质炎疫苗，应在出发前追加服用一剂。任何未接受过免疫接种，而有意前往巴基斯坦旅行的个人均应完成免疫接种的完整疗程。从巴基斯坦出发的旅客应在离开巴基斯坦前完成免疫接种的完整疗程，出发前至少要服用一剂口服脊髓灰质炎疫苗。某些无脊髓灰质炎的国家也可能会要求来自巴基斯坦的旅客进行脊髓灰质炎免疫接种，以获得入境签证。由于麦加朝圣和小朝期已经开始，预计在斋月（8月）和11月初的麦加朝圣时，将会有更多的小朝，沙特阿拉伯王国已要求（所有年龄的）小朝和麦加朝圣旅客进行免疫接种。这些要求与世卫组织国际旅行和健康中所列出的建议相一致，同时该国还额外要求，来自脊灰呈地方流行国家的所有年龄旅客提供证据，证明在前往沙特阿拉伯王国六周之前曾接受口服脊髓灰质炎疫苗免疫接种，并在抵达时追加服用一剂口服脊髓灰质炎疫苗。Poliomyelitis in PakistanPakistan has reported wild poliovirus type 3 (WPV3) isolated from a 16-month old child with onset of paralysis on 9 June 2011, from a conflict-affected, inaccessible area of Khyber Agency, Federally Administered Tribal Areas (FATA). This is the only case of WPV3 detected in Asia in 2011. WPV3 transmission in Asia is on the verge of elimination, with the last case occurring more than six months ago, on 18 November 2010 (also from Khyber Agency, FATA). Confirmation of continuation of WPV3 transmission in tribal areas of Pakistan has significant implications for the global effort to eradicate WPV3, particularly as Asia is on the verge of eliminating circulation of this strain. The detection of WPV3 in Pakistan represents the risk that it may spread from this transmission focus to other WPV3-free areas of Asia and beyond. Globally, WPV3 transmission is at historically low levels in 2011, with other circulation of this strain restricted to parts of west Africa (17 cases in C?te dIvoire, Guinea, Mali and Niger), Nigeria (five cases) and Chad (three cases). The risk of onward spread of WPV3 is deemed as high by the World Health Organization (WHO), particularly given large-scale population movements within Pakistan, between Pakistan and Afghanistan, and expected large-scale population movements associated with Umrah and the upcoming Hajj (pilgrimage to Mecca, Kingdom of Saudi Arabia) in the coming few months. In 2011, supplementary immunization activities (SIAs) in Pakistan have been inadequate in quality in key high-risk areas and a significant proportion of children remained inaccessible in conflict affected tribal areas. In FATA, particularly in Khyber agency, nearly 50% of children have been regularly missed during SIAs for the last two years. In addition to challenges relating to reaching children in insecure areas of Khyber Pakhtunkhwa and FATA, significant operational challenges continue to mar the quality of SIAs in accessible areas of Khyber and in other key transmission areas of the country, notably in the provinces of Balochistan and Sindh. In addition to confirmation of the only WPV3 case in Asia in 2011, Pakistan is affected by country-wide geographical transmission of wild poliovirus type 1 (WPV1), with 57 confirmed WPV1 cases in 2011 (as at 5 July 2011), compared with 14 WPV1 cases for the same period in 2010. To urgently address the situation, the Government of Pakistan has this year launched a National Polio Emergency Action Plan, under the auspices of His Excellency the President. However, the Independent Monitoring Board (IMB), set up at the request of the World Health Assembly (WHA) in 2010 to independently monitor progress towards a polio-free world, in April 2011 expressed alarm that the Plan is taking too long to implement, a conclusion echoed by the Technical Advisory Group (TAG) of the Eastern Mediterranean in June 2011. To rapidly build up immunity to both wild poliovirus strains, a Short Interval Additional Dose Strategy (SIAD) SIA with bivalent OPV is being conducted in Khyber Agency , the first passage on 4 July and the second on 12 July. It is expected that, as during the most recent SIAs in mid-June, 45% (89,449) of target children in Khyber Agency (80% in Bara Tehsil, i.e. approximately 73,000) will remain inaccessible during the SIADs. National Immunization Days (NIDs) will be conducted in the country on 18-20 July, using bivalent OPV (containing type 1 & 3 serotypes). However, key to success will be to overcome remaining operational challenges in fully-accessible areas and to implement special outreach strategies with full community participation to increase access to populations in security-compromised areas. To minimise the risk of WPV3 re-infecting Afghanistan, Subnational Immunization Days (SNIDs) - including in border areas with Pakistan - will be conducted in the country on 10-12 July, also using bivalent OPV. It is important that countries across Asia and the Eastern Mediterranean strengthen disease surveillance for acute flaccid paralysis (AFP), in order to rapidly detect any poliovirus importations and facilitate a rapid response should importation occur. Countries should also continue to boost routine immunization coverage against all strains of polio to minimize the consequences of any introduction. As per recommendations outlined in WHOs International travel and health, travellers to and from Pakistan should be fully protected by vaccination. Travellers to Pakistan who have in the past received three or more doses of OPV should be offered another dose of polio vaccine before departure. Any unimmunized individuals intending to travel to Pakistan should complete a full course of vaccination. Travellers from Pakistan should have a full course of vaccination against polio before leaving Pakistan,