An outbreak of type π vaccine-derived poliovirus in Sichuan province, China: emergence and circulation in an under-immunized population.

BACKGROUND: During August 2011-February 2012, an outbreak of type Π circulating vaccine-derived poliovirus (cVDPVs) occurred in Sichuan Province, China. METHODS: A field investigation of the outbreak was conducted to characterize outbreak isolates and to guide emergency response. Sequence analysis of poliovirus capsid protein VP1 was performed to determine the viral propagation, and a coverage survey was carried out for risk assessment. RESULTS: One clinical compatible polio case and three VDPV cases were determined in Ngawa County, Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan Province. Case patients were unimmunized children, 0.8-1 years old. Genetic sequencing showed that the isolates diverged from the VP1 region of the type Π Sabin strain by 5-12 nucleotides (nt) and shared the same 5 nt VP1 substitutions, which indicate single lineage of cVDPVs. Of the 7 acute flaccid paralysis cases (all>6 months) reported in Ngawa Prefecture in 2011, 4 (57.1%) cases (including 2 polio cases) did not receive oral attenuated poliovirus vaccine. Supplementary immunization activities (SIAs) were conducted in February-May, 2012, and the strain has not been isolated since. CONCLUSION: High coverage of routine immunization should be maintained among children until WPV transmission is globally eradicated. Risk assessments should be conducted regularly to pinpoint high risk areas or subpopulations, with SIAs developed if necessary.

[Assessment of health education against echinococcosis in Tibetan region of Sichuan Province, China].

OBJECTIVE: To find an effective strategy of implementing health education in Tibetan Regions so as to make echinococcosis control sustainable at a large scale. METHODS: During July to November of 2008, surveys were conducted on health education requirements among various populations in the form of questionnaire and group discussion in endemic areas of echinococcosis in three counties of the Ganzi Tibetan Autonomous Prefecture, Sichuan. Based on the obtained results, health education materials suitable for different populations were designed. The materials were applied for conducting health education in field at Tagong Township, Kangding of Ganzi in October, 2009. By the survey in May, 2010, the improved effect on knowledge and behavior change was compared before and after (6 months later) health education in order to assess the usefulness of these materials. Simultaneously, Xinduqiao Township of Kangding was selected as control. This town is neighboring to the study area with similar natural and demographic conditions, in which no health education activities related to the study was implemented. RESULTS: Various populations showed their interested requirements for health education materials and ways. Based on the information collected, a series of materials were designed and applied for health education activities in field. The results indicated that, compared with the data before health education, improvement of the knowledge and behaviors against echinococcosis among students and local residents showed significant increase (P < 0.05), but only one knowledge point about the importance of washing hands before meal among students showed no significant difference (P > 0.05) in spite of the rates increasing from 88.6% (78/88) before health education to 95.5% (84/88) after education. The local officers and monks also showed to some extent improvement on behavior manners. The rate of correct treatment of livestock viscera increased from 37.1% (13/35) and 30.3% (10/33) before the education to 82.9% (29/35) and 78.8% (26/33) (P < 0.01), while the rate of not feeding stray dogs among monks was 6.4% (3/47) before and 10.6% (5/47) (P > 0.05) after the education. The knowledge-increasing and behavior-improving rates on playing dogs among the students, residents and monks increased by 182% and 193%, 42.8% and 54.3%, 6.4% and 14.9%, respectively. There was no considerable change in the control township. CONCLUSION: The materials designed for health education are acceptable by most populations. The improvement rate of knowledge and behaviors is considerable among the groups. Use of the materials receives expected effect on health education and health promotion.