贵州省1999～2001年脊髓灰质炎疫苗病毒阳性的急性弛缓性麻痹病例流行病学分析

Epidemiological Analysis of Acute Flaccid Paralysis Cases Associated with Poliomyelitis Vaccine Virus in Guizhou Province from 1999-2001

贵州省 1999～ 2 0 0 1年从急性弛缓性麻痹 (AFP)病例粪便标本中分离到脊髓灰质炎 (脊灰 )疫苗病毒 5 3株 ,对其进行了流行病学分析。 5 3例AFP病例分布在全省 8个地区 (州、市 ,下同 )的 31个县 (市、区 ) ,发病时间无明显的聚集趋势。≤ 3岁儿童 4 8例 ,占 90 .6 % ;未免疫和未全程免疫的 38例 ,占 71.7%。其特点是 :全省 9个地区中 8个有病例 ,病例呈散在分布 ;分离出的脊灰疫苗病毒以Ⅱ型为主 (32例 ,占 6 0 .4 % ) ,3年分离的Ⅱ型脊灰疫苗病毒数均超过本年Ⅰ型和Ⅲ型的总和 ;病例中零剂次免疫儿童发病 6 0d后仍残留麻痹的占 82 .4 % ;8例高度怀疑疫苗相关麻痹型脊灰 (VAPP)病例均为 <3岁儿童 ;免疫史为零剂次和 1剂次 ;麻痹时伴发热 ,为不对称麻痹 ,发病 6 0d随访仍残留麻痹并有肌肉萎缩。提示贵州省AFP病例中检出脊灰疫苗病毒的病例 ,集中在 <3岁未免疫和未全程免疫的儿童。因此要高度重视VAPP病例 ,提高和保持高水平的常规免疫覆盖率 ,巩固AFP病例监测质量是保持无脊灰状态、及时发现输入病例和防止疫苗衍生脊灰病毒病例发生的关键。

In 1999-2001 in Guizhou Province,53 vaccine-associated polioviruses(VAPVs)were isolated from 53 of the 643 AFP cases who delivered stool specimens.The AFP cases were analyzed epidemiologically.53 AFP cases distributed in 31 counties(city,district)of 8 regions(prefecture,city,the same below)of the province.No gathering trend of disease onset was observed.90.6%(48/53)of the AFP cases were children of ≤3 years old and 21.7%(38/53)of them were unvaccinated or not full-course vaccinated.The epidemiological characteristics of the AFP cases were as follows.The cases distributed dispersely in 8 of the 9 prefectures of the province.The VAPVs isolated mainly were type Ⅱ polioviruses accounting for 60.4%(32/53)of the AFP cases.The total number the type Ⅱ VAPVs isolated within three years exceeded the sum of type Ⅰ and type Ⅲ in the same period.82.4% of the AFP cases who had zero-dose of vaccine remained residual paralysis after 60 days of disease onset.8 cases of highly suspected VAPP were all children under 3 years old,they were zero-dose or one-dose immunized.The paralysis accompanying with fever was asymmetrical.When followed up 60 day after disease onset,they had residual paralysis accompanied muscular atrophy.In conclusion,in Guizhen Province,the AFP cases from whom the VAPVs were isolated mostly were children under 3 years old unvaccinated or not full-course vaccinated.Most attention should be put on VAPP cases. For the aim of maintainting the state of polio-free,discovering rapidly the imported polio cases, preventing the incidence of vaocine-derived poliomyelitis, works for keeping a high routine immunization coverage rate and raising the surveillance quality for AFP cases are the key measures to reach the goal.