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Knowledge, attitudes and practices of caregivers regarding Japanese encephalitis in Shaanxi Province, China
p u b l i c h e a l t h 1 2 5 ( 2 0 1 1 ) 7 9 e8 3
available at www.sciencedirect.com
Public Health journal homepage: www.elsevier.com/puhe
Original Research
Knowledge, attitudes and practices of caregivers regarding Japanese encephalitis in Shaanxi Province, China S. Zhang a,e, Z. Yin b,e, C. Suraratdecha c, X. Liu a, Y. Li b, S. Hills c, K. Zhang d, Y. Chen b, X. Liang b,* a
Shaanxi Centre for Disease Prevention and Control, Xi’an, China National Immunization Programme, Chinese Centre for Disease Prevention and Control, Beijing 100050, China c Program for Appropriate Technology in Health, Seattle, USA d Baoji Prefecture Centre for Disease Prevention and Control, Baoji, China b
article info
summary
Article history:
Objectives: To describe the level of knowledge, attitudes and practices (KAP) of caregivers
Received 9 March 2010
regarding Japanese encephalitis (JE) before and after the launch of a demonstration project
Received in revised form
to transition JE vaccination into the routine Expanded Programme on Immunization and
8 September 2010
strengthen the JE immunization programme in Baoji Prefecture, Shaanxi Province; and to
Accepted 27 October 2010
identify factors determining vaccination.
Available online 1 February 2011
Study design: Cross-sectional surveys on KAP on JE disease and vaccination at baseline and post intervention.
Keywords:
Methods: KAP surveys among caregivers were conducted in six counties of Baoji Prefecture
Japanese encephalitis
using the World Health Organization probability proportional to size sampling method.
Knowledge, attitudes and practices
Results: The surveys at baseline (3781 respondents) and after a 2-year project (3780
Vaccination
respondents) demonstrated that the intervention resulted in a significant increase in the
Routine immunization
level of knowledge about, and changes in attitudes towards JE disease and vaccination, and an improvement in the proportion of children vaccinated. A probit regression of pooled pre- and post-intervention survey data suggested that knowledge, education level and age of caregivers were significantly associated with the likelihood of a child getting vaccinated. Conclusions: Routine availability of vaccine and information, education and communication strategies played important roles in improving knowledge and achieving high vaccination rates. ª 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Introduction Japanese encephalitis (JE) is a mosquito-borne viral disease affecting the central nervous system which frequently causes severe complications and death. It is the leading cause of viral
encephalitis in Asia, where approximately 30,000e50,000 cases and 10,000 deaths are estimated to occur each year.1 In China, large-scale JE epidemics occurred in the late 1960s and early 1970s, with a peak in 1971 with 174,932 cases and an incidence of 20.9 per 100,000 population.2 JE outbreaks occur
* Corresponding author. Tel.: þ86 10 63171724; fax: þ86 10 63171724. E-mail address: [email protected] (X. Liang). e These authors contributed equally to this article. 0033-3506/$ e see front matter ª 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.puhe.2010.10.011
80
p u b l i c h e a l t h 1 2 5 ( 2 0 1 1 ) 7 9 e8 3
seasonally in summer and autumn, with more than 85% of cases reported between July and September. Children under 10 years of age and under 5 years of age account for more than 80% and approximately 50% of reported cases, respectively.3 Two types of JE vaccine have been in large-scale use in China. The inactivated, primary hamster kidney cell culture vaccine, based on the Beijing P-3 virus strain, was approved and manufactured in 1968 and introduced widely in China in the 1970s. The live, attenuated vaccine (SA 14-14-2 strain) was successfully developed in the late 1980s, licensed for use in China in 1988, and has subsequently been used in many other countries, such as India, Nepal and the Republic of Korea.4,5 According to the Chinese Ministry of Health’s (MOH) recommended schedules in 2005, the two primary doses of inactivated vaccine should be administered to children at 8 months of age, with a 7e10-day interval, whereas only one primary dose is required for the live, attenuated vaccine. Both vaccines require two boosters at 18e24 months of age and 72 months of age. The incidence of JE has decreased continuously since the introduction of these vaccines, from less than 10 per 100,000 in 1974 to less than 1 per 100,000 population in 1996.2 However, outbreaks occur periodically,6 and as many as 5000e8000 cases are still reported each year with hundreds of deaths and disabilities.3,7 The China MOH continuously seeks to enhance the JE disease control programme, and issued the ‘Guidelines for Japanese Encephalitis Control and Prevention’ in March 2004 with the aim of improving JE vaccine coverage and decreasing JE incidence through multiple strategies. These strategies included providing JE vaccine free of charge, enhancing JE disease surveillance, conducting health education, and controlling vectors of JE virus. The guidelines recommend that JE vaccine should be provided routinely in the Expanded Programme on Immunization (EPI) in JE-endemic areas, rather than administered in campaigns before the JE season. In collaboration with the Chinese Centre for Disease Prevention and Control (CDC) and Program for Appropriate Technology in Health (PATH), the Shaanxi CDC launched a demonstration project in April 2005 to implement the MOH guidelines on JE control in Baoji Prefecture, Shaanxi Province. Shaanxi is located in the eastern part of Northwest China and had a total population of 36.6 million in 2005. It has 10 prefectures, one development district and 106 counties, and is ranked among the top five JE-endemic provinces in China. Baoji Prefecture had a population of 3.7 million in 2005 and covers 12 counties. The highest reported JE incidence was 23.1 per 100,000 in 1975. Baoji is one of the three prefectures with the highest reported annual incidence of JE in Shaanxi Province. Several large JE epidemics have occurred in the past, with a peak incidence of 18.2 per 100,000 in 1975. Following the use of vaccines, the incidence decreased to 0.7e3.6 per 100,000 population annually in 1995e2004.8 Prior to May 2005, JE vaccine was available in Shaanxi Province through annual campaigns conducted from April to May, and was subject to a user fee. Since May 2005, in order to strengthen JE control efforts, JE vaccine has been integrated into the routine EPI and is available free of charge on a monthly basis except during the JE season. Activities to support the demonstration project to integrate JE vaccine into the routine EPI in Baoji Prefecture included: training doctors and EPI staff
to ensure a minimum level of knowledge regarding JE disease, prevention and control; establishing a JE surveillance system; enhancing the reporting system of adverse events following immunization; developing social mobilization and public education materials; increasing social mobilization activities to actively encourage parents to immunize their children; and strengthening vaccinator supervision to ensure routine immunization service quality, including the JE immunization service. The objectives of this paper were to describe the level of knowledge, attitudes and practices (KAP) of caregivers in relation to JE before and after the launch of the demonstration project in Baoji Prefecture, Shaanxi Province; and to identify factors determining vaccination.
Methods The surveys assessing KAP regarding JE were carried out in six counties (Feng, Fengxiang, Fufeng, Linyou, Mei and Qishan) of Baoji Prefecture at baseline in April 2005 and at the end of the demonstration project in May 2007. These sites were selected taking into account variations in economic status and topography, and divided into lower economic/mountainous (Feng and Linyou counties) and higher economic/plains (Fengxiang, Fufeng, Mei and Qishan counties) areas. In each county, households with children aged 9e21 months, 3 years or 7 years who were eligible for the first, second or third dose of vaccine were identified, and the primary caregivers of children were recruited to participate in the surveys. In each survey, a total of 3780 households (630 households per county) were targeted using the World Health Organization probability proportional to size sampling method.9 Trained epidemiologists from Baoji Prefecture CDC obtained oral consent and interviewed a primary caregiver in each household. The epidemiology staff at Shaanxi CDC planned and supervised the surveys. The questionnaire addressed background information on respondents (age and education) and assessed KAP regarding JE disease and immunization. JE vaccination status was defined as whether the child received the vaccine based on their immunization card. The baseline survey was carried out from 12 to 17 April 2005, and the final survey was conducted from 13 to 20 April 2007. This work received ethical approval from the Chinese CDC’s and PATH’s ethics committees. The database was created using EpiData 3.1 (EpiData Association, Odense M, Denmark) and data were analysed using Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) and STATA (StataCorp LP, Texas, USA). A probit regression was conducted to identify determinants of vaccination status, and statistically significant differences in KAP before and after the intervention were assessed using t-tests and Chi-squared tests.
Results In total, 3781 and 3780 caregivers were interviewed during the baseline and final surveys, respectively. Table 1 displays the characteristics of respondents. The average age of caregivers was 41 years in both surveys, but was slightly lower in the final sample (P < 0.05). More than half of the respondents were
81
p u b l i c h e a l t h 1 2 5 ( 2 0 1 1 ) 7 9 e8 3
Table 1 e Characteristics of caregivers in baseline and final surveys. Variable
Baseline (n ¼ 3781)
Final (n ¼ 3780)
P
41.8
41.1
0.032a <0.001b
59.7 37.4 2.9
64.0 34.9 1.1
28.1 24.3
21.3 23.3
38.7
44.8
6.6
8.0
2.4
2.5
Mean age (years) Primary caregiver (%) Parent Grandparent Other Education (%) No schooling Primary school (6 years of education) Secondary school (7e9 years of education) High school (10e12 years of education) College and above (>12 years of education)
<0.001b
a Using t-test. b Using Chi-squared test.
parents; the others were grandparents and other relatives. There was a higher proportion of caregivers with a secondary education than with other levels of education, and less than 10% of caregivers had a high school education or higher.
Japanese encephalitis disease
Table 2 e Caregivers’ responses on Japanese encephalitis (JE) disease and immunization. Pa
Baseline
Final
(%)
(%)
56.1
91.5
<0.001
18.2 75.2 1.4 5.3
24.7 70.1 2.2 4.4
<0.001 <0.001 0.038 0.275
55.9
75.6
<0.001
27.3
17.5
<0.001
16.2
15.8
0.685
33.6 22.4
72.5 56.6
<0.001 <0.001
16.9
42.7
<0.001
66.2
92.3
<0.001
0.8
3.0
<0.001
61.2 81.8
94.0 98.8
<0.001 <0.001
11.2
37.5
<0.001
55.3
82.6
<0.001
Ever heard of a disease that infects the brain called JE Describe the disease as severe Describe the disease as moderate Describe the disease as mild Adults are most likely to get sick with the disease Children are most likely to get sick with the disease My child is at risk of getting sick with JE People sick with this disease normally recover completely JE disease is spread by mosquitoes JE disease can be prevented by killing mosquitoes JE disease can be prevented by using bed nets JE disease can be prevented by immunizing children JE disease can be prevented by immunizing pigs Ever heard of JE vaccine JE vaccine is as important as other childhood vaccines Correct answer on age of child at first dose My child received JE vaccine
Table 2 presents responses to questions on JE disease at baseline and post intervention. The proportion of respondents who knew about and were aware of the disease was higher in the final survey compared with the baseline survey. Chi-squared tests showed significant improvement in knowledge about the disease. The proportion of respondents who had heard of JE increased significantly (56.1% vs 91.5%, P < 0.001). More than 90% of caregivers who had heard of JE perceived that the disease was severe or moderate. More (fewer) caregivers in the final survey thought that the disease was severe (moderate). There was a significant increase in the final survey in the proportion of caregivers who believed that children in the population were most likely to get sick with the disease (55.9% vs 75.6%, P < 0.001). The percentage of caregivers who felt that their child was at risk of getting sick with JE decreased significantly. The proportion of caregivers who responded that JE was spread by mosquitoes increased significantly (33.6% vs 72.5%, P < 0.001), as did the proportion of caregivers who responded that JE can be prevented by childhood immunization (66.2% vs 92.3%, P < 0.001). Other preventive measures reported included killing mosquitoes, using bed nets and immunizing pigs.
childhood vaccinations (e.g. measles and polio). Approximately 37.5% of respondents in the final survey were able to correctly describe the first dose schedule, compared with 11.2% at baseline. There was an increase (from 55.3% to 82.6%, P < 0.001) in the proportion of caregivers who reported that their children had ever received a JE vaccine. The reported common reasons for non-vaccination in the baseline survey were ‘vaccine is only available once a year’ (75.1%) and ‘didn’t know where to receive a vaccine’ (19.7%); in the final survey, the main reasons were ‘a child was ill’ (48.2%) and ‘didn’t know when to vaccinate’ (24.7%). In the final survey, respondents were asked to identify where they had gained information about JE vaccination. Of 3554 responses, talking with medical staff was the main reported resource (86.6%), followed by television (40.2%) and leaflets (37.2%). Blackboards and posters seemed to be more appropriate among caregivers with a secondary education or higher (data not shown).
Japanese encephalitis immunization
Determinants of vaccination status
Chi-squared tests show a significant difference in the level of KAP related to JE immunization among caregivers between the baseline and post-intervention surveys (Table 2). More than 90% of respondents in the final survey had heard of a JE vaccine; the proportion increased from 61.2% at baseline to 94.0% (P < 0.001). Of those, 81.8% (baseline) vs 98.8% (final) thought that JE vaccination was as important as other
Table 3 provides the results from a probit regression of the pooled baseline and follow-up data of respondents who had ever heard of a JE vaccine (n ¼ 5867), controlling for age, education and type of caregiver. The proportion of caregivers reporting that their children had received at lest one dose of JE vaccine was 71.9%. The regression was conducted using vaccination status as the dichotomous dependent variable,
a Using Chi-squared test.
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p u b l i c h e a l t h 1 2 5 ( 2 0 1 1 ) 7 9 e8 3
Table 3 e Probit of the probability of vaccination (pooled baseline and follow-up survey data). Variable
Marginal effectsb
Period (¼1 if baseline, otherwise ¼ 0)
0.214***
Demographica Age 25e34 (¼1 if aged 25e34, otherwise ¼ 0) Age 35e44 (¼1 if aged 35e44, otherwise ¼ 0) Age 45e54 (¼1 if aged 45e54, otherwise ¼ 0) Age 55þ (¼1 if aged 55 or higher, otherwise ¼ 0) Primary (¼1 if highest is primary, otherwise ¼ 0) Secondary (¼1 if highest is secondary, otherwise ¼ 0) High schoolþ (¼1 if highest is high school or higher, otherwise ¼ 0) Grandparent (¼1 if caregiver is grandparent, otherwise ¼ 0) Other caregiver (¼1 if caregiver is not parent or grandparent, otherwise ¼ 0)
0.110*** 0.072** 0.084 0.070 0.039* 0.080*** 0.104*** 0.009 0.230***
Knowledge and attitude Transmitted by mosquitoes (¼1 if knows that JE is transmitted by mosquitoes, otherwise ¼ 0) Preventive measure (¼1 if answered any method to prevent JE correctly, otherwise ¼ 0) Age at first dose (¼1 if answered correctly the timing of first dose of JE vaccine, otherwise ¼ 0) Vaccine is important (¼1 if believes JE vaccine is as important as other vaccines, otherwise ¼ 0) Severe (¼1 if believes JE is a severe disease, otherwise ¼ 0) Child’s risk of getting JE (¼1 if believes the child is at risk, otherwise ¼ 0)
0.068*** 0.021 0.067*** 0.004 0.019 0.017
Number of observations Likelihood Ratio c2 Probability > c2 Pseudo R2 Observed probability Predicted probability (at the mean)
5867 636.34 0.000 0.091 0.718 0.736
a Omitted age category is 24 years or lower; omitted education category is no formal education; omitted type of caregiver category is parent. b ***,** and * denote statistical significance of the estimated underlying probit coefficient, not the marginal effects, at the 0.01, 0.05 and 0.10 levels, respectively.
which equalled 1 if the child was vaccinated with at least one dose of JE vaccine according to the immunization card, and 0 otherwise. The findings suggest that during the 2-year intervention, knowledge that JE was transmitted by mosquitoes and the timing of the first dose of JE vaccine were significantly likely to increase the chance of a child getting vaccinated. The statistical significance of the period variable (indicating pre or post survey) indicates that regardless of other factors, children were more likely to receive JE vaccines during the intervention period than prior to the project launch. The probit coefficients were transformed into marginal changes in the probability of vaccinating for a one-unit change in the explanatory variables, evaluated at the mean (marginal effects). For the dichotomous explanatory variables, the marginal change evaluates the dependent variable comparing when the value is set to 1 with when it is set to 0. The estimated marginal effects indicate the independent effect on the predicted probability of a change in the variables of age, education and type of caregiver relative to the omitted variables (aged less than 25 years, had no education and being a parent). The significant coefficients show that age, education and type of caregiver variables were associated with a child’s vaccination status. All else held constant, being young (aged 25e44 years) increased the probability of being vaccinated by 7e11%. Knowledge of disease transmission and vaccination schedule increased the probability of vaccination by 6.8% and 6.7%, respectively, with all else held constant. Caregivers aged 25e34 years and 35e44 years were more likely to have their children vaccinated than caregivers aged less than 25 years (omitted age group). Older caregivers (age 45 years or more) and
grandparents did not have the same impact on vaccination status relative to caregivers aged less than 25 years. Other types of caregivers, compared with parents, were negatively associated with vaccination status. If a caregiver had some level of formal education, the probability of their child being vaccinated was lower compared with those with no formal education.
Discussion This study is the first to describe caregivers’ KAP regarding JE, and factors associated with JE vaccination. The survey findings show a significant improvement in KAP of caregivers pre and post intervention. KAP studies have generally focused on the knowledge and attitudes of the mother or parent, and have not included other primary caregivers.10e12 The findings from this study demonstrated that the likelihood of vaccination was associated with the type of caregiver. The overall proportion of caregivers who had ever heard of JE disease was relatively lower than that of caregivers who had ever heard of a JE vaccine in both the pre- and post-intervention surveys. The regression analysis showed that knowledge of the disease and vaccine was associated with vaccination status. The majority of caregivers knew that immunizing children could prevent the disease. JE vaccine has been available in Shaanxi Province through campaigns since the 1970s. Although more than 80% of caregivers perceived that JE vaccination was as important as other vaccinations, the level of knowledge and vaccination coverage was relatively low at baseline compared with that seen after the transition into the routine immunization
p u b l i c h e a l t h 1 2 5 ( 2 0 1 1 ) 7 9 e8 3
programme with supporting activities during the intervention. The availability of vaccine in the routine programme was also likely to have contributed to the improvement in the vaccination rate, consistent with this being the most commonly cited reason for not vaccinating in the baseline survey. Interestingly, although JE outbreaks occur periodically, caregivers tended to have the attitude that there was a low risk of a child getting sick with JE, and the perceived risk was not associated with vaccination status. This might be because of the availability of vaccines in Shaanxi Province. Caregivers aged less than 25 years were less likely to have a child vaccinated. In addition, the results suggest that the probability of a child getting vaccinated decreased with the education level of caregivers. Although higher education is usually associated with higher immunization coverage in less-developed countries,13 this finding is well supported by published literature. The high level of education of Dutch parents was identified as one of the determinants of a negative attitude towards having their child vaccinated.14 Opstelten et al. also reported a higher prevalence of non-compliers with influenza and pneumococcal vaccination among highly educated elderly persons.15 Additionally, China has significant variations in development levels across provinces and prefectures. Baoji Prefecture is highly developed and has relatively higher income than other prefectures in Shaanxi Province. Therefore, educated caregivers may have negative attitudes similar to those in developed countries. A limitation of this study is that the regression analysis does not include the whole sample because caregivers who had not heard of a JE vaccine were excluded from answering the question on vaccination status. This would underestimate the effect of demographic variables. It is not possible to identify and quantify the components of the interventions that contributed to significant changes and improvement in KAP. A number of factors could have contributed because several aspects of the intervention [e.g. improving access to vaccine through monthly availability; providing vaccine free of charge; introducing information, education and communication (IEC) activities at both provider and community levels] were implemented simultaneously. Additionally, an economic variable, which was not captured in the survey, may be associated with vaccination status. The findings, however, highlight the importance of routine immunization and the necessity for IEC activities targeting young and educated caregivers to improve knowledge of disease and vaccination coverage. Efforts should be made to identify appropriate types of media and IEC messages to reach caregivers with different demographic profiles.
Ethical approval Ethical review committees at Chinese Centre for Disease Prevention and Control and PATH.
Funding PATH Japanese Encephalitis Project, which was funded by the Bill & Melinda Gates Foundation (Grant 28658).
Competing interests None declared.
83
Acknowledgements The authors are grateful for the contributions of staff at the Chinese CDC, Shaanxi Province CDC, Baoji Prefecture CDC, and county CDCs, Lixia Wang, Junfeng Yang, and the health staff and caregivers whose support and participation made this project successful. Special thanks go to Erin Kester for editing and manuscript preparation.
references
1. Solomon T, Ni H, Beasley DW, Ekkelenkamp M, Cardosa MJ, Barrett AD. Origin and evolution of Japanese encephalitis virus in Southeast Asia. J Virol 2003;77:3091e8. 2. Wang X, Lu Y, Zhang Y, Chen Y, Lian X. Dynamic tendency of Japanese B encephalitis in China. Chin J Vaccine Immunization 2004;10:302e4 [in Chinese]. 3. Li Y, Yin Z, Zhang Y, Chen Y, Nin X, Li L. Epidemiological characteristic analysis of Japanese encephalitis in China during 2004e2006. Chin J Vaccine Immunization 2007;13:825e30 [in Chinese]. 4. Zhao B, Yan J. Production and application about Japanese encephalitis in China. Chin J Vaccine Immunization 1998;4: 168e71 [in Chinese]. 5. Fischer M, Hills S, Staples E, Johnson B, Yaı¨ch M, Solomon T. Japanese encephalitis prevention and control: advances, challenges, and new initiatives. In: Scheld WM, Hammer S, Hughes JM, editors. Emerging infections, vol. 8. Washington, DC: American Society for Microbiology; 2008. p. 93e124. 6. Wang LH, Fu SH, Wang HY, Liang XF, Cheng JX, Jing HM, et al. Japanese encephalitis outbreak, Yuncheng, China 2006. Emerging Infect Dis 2007;13:1123e5. 7. Wang X, Zhang Y, Zhang R, Chen Y, Liang X. Analysis on epidemic trend of Japanese B encephalitis during 1998e2002 in China. Chin J Vaccine Immunization 2004;10:215e7 [in Chinese]. 8. Zhang S, Xia X, Xu Y. Analysis of the epidemic characteristics of Japanese B encephalitis in Shaanxi Province during 1960e2004. Chin J Vaccine Immunization 2006;12:199e200. [in Chinese]. 9. World Health Organization. The EPI coverage survey. WHO/EPI/ MLM/91.10. Geneva: World Health Organization; 1991. 10. Matsumura T, Nakayama T, Okamoto S, Ito H. Measles vaccine coverage and factors related to uncompleted vaccination among 18-month-old and 36-month-old children in Kyoto, Japan. BMC Public Health 2005;5:59. 11. Torun SD, Bakirci N. Vaccination coverage and reasons for non-vaccination in a district of Istanbul. BMC Public Health 2006;6:125. 12. Odusanya OO, Alufohai EF, Meurice FP, Ahonkhai VI. Determinants of vaccination coverage in rural Nigeria. BMC Public Health 2008;8:381. 13. Hadler SC, Dietz V, Okwo-Bele JM, Cutts FT. Immunization in developing countries. In: Plotkin SA, Orenstein WA, Offit PA, editors. Vaccines. 5th ed. Philadelphia, PA: Elsevier Health Sciences; 2008. 14. Hak E, Schonbeck Y, De MH, Van Essen GA, Sanders EA. Negative attitude of highly educated parents and health care workers towards future vaccinations in the Dutch childhood vaccination program. Vaccine 2005;23:3103e7. 15. Opstelten W, Hak E, Verheij TJ, Van Essen GA. Introducing a pneumococcal vaccine to an existing influenza immunization program: vaccination rates and predictors of noncompliance. Am J Med 2001;111:474e9.
available at www.sciencedirect.com
Public Health journal homepage: www.elsevier.com/puhe
Original Research
Knowledge, attitudes and practices of caregivers regarding Japanese encephalitis in Shaanxi Province, China S. Zhang a,e, Z. Yin b,e, C. Suraratdecha c, X. Liu a, Y. Li b, S. Hills c, K. Zhang d, Y. Chen b, X. Liang b,* a
Shaanxi Centre for Disease Prevention and Control, Xi’an, China National Immunization Programme, Chinese Centre for Disease Prevention and Control, Beijing 100050, China c Program for Appropriate Technology in Health, Seattle, USA d Baoji Prefecture Centre for Disease Prevention and Control, Baoji, China b
article info
summary
Article history:
Objectives: To describe the level of knowledge, attitudes and practices (KAP) of caregivers
Received 9 March 2010
regarding Japanese encephalitis (JE) before and after the launch of a demonstration project
Received in revised form
to transition JE vaccination into the routine Expanded Programme on Immunization and
8 September 2010
strengthen the JE immunization programme in Baoji Prefecture, Shaanxi Province; and to
Accepted 27 October 2010
identify factors determining vaccination.
Available online 1 February 2011
Study design: Cross-sectional surveys on KAP on JE disease and vaccination at baseline and post intervention.
Keywords:
Methods: KAP surveys among caregivers were conducted in six counties of Baoji Prefecture
Japanese encephalitis
using the World Health Organization probability proportional to size sampling method.
Knowledge, attitudes and practices
Results: The surveys at baseline (3781 respondents) and after a 2-year project (3780
Vaccination
respondents) demonstrated that the intervention resulted in a significant increase in the
Routine immunization
level of knowledge about, and changes in attitudes towards JE disease and vaccination, and an improvement in the proportion of children vaccinated. A probit regression of pooled pre- and post-intervention survey data suggested that knowledge, education level and age of caregivers were significantly associated with the likelihood of a child getting vaccinated. Conclusions: Routine availability of vaccine and information, education and communication strategies played important roles in improving knowledge and achieving high vaccination rates. ª 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Introduction Japanese encephalitis (JE) is a mosquito-borne viral disease affecting the central nervous system which frequently causes severe complications and death. It is the leading cause of viral
encephalitis in Asia, where approximately 30,000e50,000 cases and 10,000 deaths are estimated to occur each year.1 In China, large-scale JE epidemics occurred in the late 1960s and early 1970s, with a peak in 1971 with 174,932 cases and an incidence of 20.9 per 100,000 population.2 JE outbreaks occur
* Corresponding author. Tel.: þ86 10 63171724; fax: þ86 10 63171724. E-mail address: [email protected] (X. Liang). e These authors contributed equally to this article. 0033-3506/$ e see front matter ª 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.puhe.2010.10.011
80
p u b l i c h e a l t h 1 2 5 ( 2 0 1 1 ) 7 9 e8 3
seasonally in summer and autumn, with more than 85% of cases reported between July and September. Children under 10 years of age and under 5 years of age account for more than 80% and approximately 50% of reported cases, respectively.3 Two types of JE vaccine have been in large-scale use in China. The inactivated, primary hamster kidney cell culture vaccine, based on the Beijing P-3 virus strain, was approved and manufactured in 1968 and introduced widely in China in the 1970s. The live, attenuated vaccine (SA 14-14-2 strain) was successfully developed in the late 1980s, licensed for use in China in 1988, and has subsequently been used in many other countries, such as India, Nepal and the Republic of Korea.4,5 According to the Chinese Ministry of Health’s (MOH) recommended schedules in 2005, the two primary doses of inactivated vaccine should be administered to children at 8 months of age, with a 7e10-day interval, whereas only one primary dose is required for the live, attenuated vaccine. Both vaccines require two boosters at 18e24 months of age and 72 months of age. The incidence of JE has decreased continuously since the introduction of these vaccines, from less than 10 per 100,000 in 1974 to less than 1 per 100,000 population in 1996.2 However, outbreaks occur periodically,6 and as many as 5000e8000 cases are still reported each year with hundreds of deaths and disabilities.3,7 The China MOH continuously seeks to enhance the JE disease control programme, and issued the ‘Guidelines for Japanese Encephalitis Control and Prevention’ in March 2004 with the aim of improving JE vaccine coverage and decreasing JE incidence through multiple strategies. These strategies included providing JE vaccine free of charge, enhancing JE disease surveillance, conducting health education, and controlling vectors of JE virus. The guidelines recommend that JE vaccine should be provided routinely in the Expanded Programme on Immunization (EPI) in JE-endemic areas, rather than administered in campaigns before the JE season. In collaboration with the Chinese Centre for Disease Prevention and Control (CDC) and Program for Appropriate Technology in Health (PATH), the Shaanxi CDC launched a demonstration project in April 2005 to implement the MOH guidelines on JE control in Baoji Prefecture, Shaanxi Province. Shaanxi is located in the eastern part of Northwest China and had a total population of 36.6 million in 2005. It has 10 prefectures, one development district and 106 counties, and is ranked among the top five JE-endemic provinces in China. Baoji Prefecture had a population of 3.7 million in 2005 and covers 12 counties. The highest reported JE incidence was 23.1 per 100,000 in 1975. Baoji is one of the three prefectures with the highest reported annual incidence of JE in Shaanxi Province. Several large JE epidemics have occurred in the past, with a peak incidence of 18.2 per 100,000 in 1975. Following the use of vaccines, the incidence decreased to 0.7e3.6 per 100,000 population annually in 1995e2004.8 Prior to May 2005, JE vaccine was available in Shaanxi Province through annual campaigns conducted from April to May, and was subject to a user fee. Since May 2005, in order to strengthen JE control efforts, JE vaccine has been integrated into the routine EPI and is available free of charge on a monthly basis except during the JE season. Activities to support the demonstration project to integrate JE vaccine into the routine EPI in Baoji Prefecture included: training doctors and EPI staff
to ensure a minimum level of knowledge regarding JE disease, prevention and control; establishing a JE surveillance system; enhancing the reporting system of adverse events following immunization; developing social mobilization and public education materials; increasing social mobilization activities to actively encourage parents to immunize their children; and strengthening vaccinator supervision to ensure routine immunization service quality, including the JE immunization service. The objectives of this paper were to describe the level of knowledge, attitudes and practices (KAP) of caregivers in relation to JE before and after the launch of the demonstration project in Baoji Prefecture, Shaanxi Province; and to identify factors determining vaccination.
Methods The surveys assessing KAP regarding JE were carried out in six counties (Feng, Fengxiang, Fufeng, Linyou, Mei and Qishan) of Baoji Prefecture at baseline in April 2005 and at the end of the demonstration project in May 2007. These sites were selected taking into account variations in economic status and topography, and divided into lower economic/mountainous (Feng and Linyou counties) and higher economic/plains (Fengxiang, Fufeng, Mei and Qishan counties) areas. In each county, households with children aged 9e21 months, 3 years or 7 years who were eligible for the first, second or third dose of vaccine were identified, and the primary caregivers of children were recruited to participate in the surveys. In each survey, a total of 3780 households (630 households per county) were targeted using the World Health Organization probability proportional to size sampling method.9 Trained epidemiologists from Baoji Prefecture CDC obtained oral consent and interviewed a primary caregiver in each household. The epidemiology staff at Shaanxi CDC planned and supervised the surveys. The questionnaire addressed background information on respondents (age and education) and assessed KAP regarding JE disease and immunization. JE vaccination status was defined as whether the child received the vaccine based on their immunization card. The baseline survey was carried out from 12 to 17 April 2005, and the final survey was conducted from 13 to 20 April 2007. This work received ethical approval from the Chinese CDC’s and PATH’s ethics committees. The database was created using EpiData 3.1 (EpiData Association, Odense M, Denmark) and data were analysed using Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) and STATA (StataCorp LP, Texas, USA). A probit regression was conducted to identify determinants of vaccination status, and statistically significant differences in KAP before and after the intervention were assessed using t-tests and Chi-squared tests.
Results In total, 3781 and 3780 caregivers were interviewed during the baseline and final surveys, respectively. Table 1 displays the characteristics of respondents. The average age of caregivers was 41 years in both surveys, but was slightly lower in the final sample (P < 0.05). More than half of the respondents were
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p u b l i c h e a l t h 1 2 5 ( 2 0 1 1 ) 7 9 e8 3
Table 1 e Characteristics of caregivers in baseline and final surveys. Variable
Baseline (n ¼ 3781)
Final (n ¼ 3780)
P
41.8
41.1
0.032a <0.001b
59.7 37.4 2.9
64.0 34.9 1.1
28.1 24.3
21.3 23.3
38.7
44.8
6.6
8.0
2.4
2.5
Mean age (years) Primary caregiver (%) Parent Grandparent Other Education (%) No schooling Primary school (6 years of education) Secondary school (7e9 years of education) High school (10e12 years of education) College and above (>12 years of education)
<0.001b
a Using t-test. b Using Chi-squared test.
parents; the others were grandparents and other relatives. There was a higher proportion of caregivers with a secondary education than with other levels of education, and less than 10% of caregivers had a high school education or higher.
Japanese encephalitis disease
Table 2 e Caregivers’ responses on Japanese encephalitis (JE) disease and immunization. Pa
Baseline
Final
(%)
(%)
56.1
91.5
<0.001
18.2 75.2 1.4 5.3
24.7 70.1 2.2 4.4
<0.001 <0.001 0.038 0.275
55.9
75.6
<0.001
27.3
17.5
<0.001
16.2
15.8
0.685
33.6 22.4
72.5 56.6
<0.001 <0.001
16.9
42.7
<0.001
66.2
92.3
<0.001
0.8
3.0
<0.001
61.2 81.8
94.0 98.8
<0.001 <0.001
11.2
37.5
<0.001
55.3
82.6
<0.001
Ever heard of a disease that infects the brain called JE Describe the disease as severe Describe the disease as moderate Describe the disease as mild Adults are most likely to get sick with the disease Children are most likely to get sick with the disease My child is at risk of getting sick with JE People sick with this disease normally recover completely JE disease is spread by mosquitoes JE disease can be prevented by killing mosquitoes JE disease can be prevented by using bed nets JE disease can be prevented by immunizing children JE disease can be prevented by immunizing pigs Ever heard of JE vaccine JE vaccine is as important as other childhood vaccines Correct answer on age of child at first dose My child received JE vaccine
Table 2 presents responses to questions on JE disease at baseline and post intervention. The proportion of respondents who knew about and were aware of the disease was higher in the final survey compared with the baseline survey. Chi-squared tests showed significant improvement in knowledge about the disease. The proportion of respondents who had heard of JE increased significantly (56.1% vs 91.5%, P < 0.001). More than 90% of caregivers who had heard of JE perceived that the disease was severe or moderate. More (fewer) caregivers in the final survey thought that the disease was severe (moderate). There was a significant increase in the final survey in the proportion of caregivers who believed that children in the population were most likely to get sick with the disease (55.9% vs 75.6%, P < 0.001). The percentage of caregivers who felt that their child was at risk of getting sick with JE decreased significantly. The proportion of caregivers who responded that JE was spread by mosquitoes increased significantly (33.6% vs 72.5%, P < 0.001), as did the proportion of caregivers who responded that JE can be prevented by childhood immunization (66.2% vs 92.3%, P < 0.001). Other preventive measures reported included killing mosquitoes, using bed nets and immunizing pigs.
childhood vaccinations (e.g. measles and polio). Approximately 37.5% of respondents in the final survey were able to correctly describe the first dose schedule, compared with 11.2% at baseline. There was an increase (from 55.3% to 82.6%, P < 0.001) in the proportion of caregivers who reported that their children had ever received a JE vaccine. The reported common reasons for non-vaccination in the baseline survey were ‘vaccine is only available once a year’ (75.1%) and ‘didn’t know where to receive a vaccine’ (19.7%); in the final survey, the main reasons were ‘a child was ill’ (48.2%) and ‘didn’t know when to vaccinate’ (24.7%). In the final survey, respondents were asked to identify where they had gained information about JE vaccination. Of 3554 responses, talking with medical staff was the main reported resource (86.6%), followed by television (40.2%) and leaflets (37.2%). Blackboards and posters seemed to be more appropriate among caregivers with a secondary education or higher (data not shown).
Japanese encephalitis immunization
Determinants of vaccination status
Chi-squared tests show a significant difference in the level of KAP related to JE immunization among caregivers between the baseline and post-intervention surveys (Table 2). More than 90% of respondents in the final survey had heard of a JE vaccine; the proportion increased from 61.2% at baseline to 94.0% (P < 0.001). Of those, 81.8% (baseline) vs 98.8% (final) thought that JE vaccination was as important as other
Table 3 provides the results from a probit regression of the pooled baseline and follow-up data of respondents who had ever heard of a JE vaccine (n ¼ 5867), controlling for age, education and type of caregiver. The proportion of caregivers reporting that their children had received at lest one dose of JE vaccine was 71.9%. The regression was conducted using vaccination status as the dichotomous dependent variable,
a Using Chi-squared test.
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Table 3 e Probit of the probability of vaccination (pooled baseline and follow-up survey data). Variable
Marginal effectsb
Period (¼1 if baseline, otherwise ¼ 0)
0.214***
Demographica Age 25e34 (¼1 if aged 25e34, otherwise ¼ 0) Age 35e44 (¼1 if aged 35e44, otherwise ¼ 0) Age 45e54 (¼1 if aged 45e54, otherwise ¼ 0) Age 55þ (¼1 if aged 55 or higher, otherwise ¼ 0) Primary (¼1 if highest is primary, otherwise ¼ 0) Secondary (¼1 if highest is secondary, otherwise ¼ 0) High schoolþ (¼1 if highest is high school or higher, otherwise ¼ 0) Grandparent (¼1 if caregiver is grandparent, otherwise ¼ 0) Other caregiver (¼1 if caregiver is not parent or grandparent, otherwise ¼ 0)
0.110*** 0.072** 0.084 0.070 0.039* 0.080*** 0.104*** 0.009 0.230***
Knowledge and attitude Transmitted by mosquitoes (¼1 if knows that JE is transmitted by mosquitoes, otherwise ¼ 0) Preventive measure (¼1 if answered any method to prevent JE correctly, otherwise ¼ 0) Age at first dose (¼1 if answered correctly the timing of first dose of JE vaccine, otherwise ¼ 0) Vaccine is important (¼1 if believes JE vaccine is as important as other vaccines, otherwise ¼ 0) Severe (¼1 if believes JE is a severe disease, otherwise ¼ 0) Child’s risk of getting JE (¼1 if believes the child is at risk, otherwise ¼ 0)
0.068*** 0.021 0.067*** 0.004 0.019 0.017
Number of observations Likelihood Ratio c2 Probability > c2 Pseudo R2 Observed probability Predicted probability (at the mean)
5867 636.34 0.000 0.091 0.718 0.736
a Omitted age category is 24 years or lower; omitted education category is no formal education; omitted type of caregiver category is parent. b ***,** and * denote statistical significance of the estimated underlying probit coefficient, not the marginal effects, at the 0.01, 0.05 and 0.10 levels, respectively.
which equalled 1 if the child was vaccinated with at least one dose of JE vaccine according to the immunization card, and 0 otherwise. The findings suggest that during the 2-year intervention, knowledge that JE was transmitted by mosquitoes and the timing of the first dose of JE vaccine were significantly likely to increase the chance of a child getting vaccinated. The statistical significance of the period variable (indicating pre or post survey) indicates that regardless of other factors, children were more likely to receive JE vaccines during the intervention period than prior to the project launch. The probit coefficients were transformed into marginal changes in the probability of vaccinating for a one-unit change in the explanatory variables, evaluated at the mean (marginal effects). For the dichotomous explanatory variables, the marginal change evaluates the dependent variable comparing when the value is set to 1 with when it is set to 0. The estimated marginal effects indicate the independent effect on the predicted probability of a change in the variables of age, education and type of caregiver relative to the omitted variables (aged less than 25 years, had no education and being a parent). The significant coefficients show that age, education and type of caregiver variables were associated with a child’s vaccination status. All else held constant, being young (aged 25e44 years) increased the probability of being vaccinated by 7e11%. Knowledge of disease transmission and vaccination schedule increased the probability of vaccination by 6.8% and 6.7%, respectively, with all else held constant. Caregivers aged 25e34 years and 35e44 years were more likely to have their children vaccinated than caregivers aged less than 25 years (omitted age group). Older caregivers (age 45 years or more) and
grandparents did not have the same impact on vaccination status relative to caregivers aged less than 25 years. Other types of caregivers, compared with parents, were negatively associated with vaccination status. If a caregiver had some level of formal education, the probability of their child being vaccinated was lower compared with those with no formal education.
Discussion This study is the first to describe caregivers’ KAP regarding JE, and factors associated with JE vaccination. The survey findings show a significant improvement in KAP of caregivers pre and post intervention. KAP studies have generally focused on the knowledge and attitudes of the mother or parent, and have not included other primary caregivers.10e12 The findings from this study demonstrated that the likelihood of vaccination was associated with the type of caregiver. The overall proportion of caregivers who had ever heard of JE disease was relatively lower than that of caregivers who had ever heard of a JE vaccine in both the pre- and post-intervention surveys. The regression analysis showed that knowledge of the disease and vaccine was associated with vaccination status. The majority of caregivers knew that immunizing children could prevent the disease. JE vaccine has been available in Shaanxi Province through campaigns since the 1970s. Although more than 80% of caregivers perceived that JE vaccination was as important as other vaccinations, the level of knowledge and vaccination coverage was relatively low at baseline compared with that seen after the transition into the routine immunization
p u b l i c h e a l t h 1 2 5 ( 2 0 1 1 ) 7 9 e8 3
programme with supporting activities during the intervention. The availability of vaccine in the routine programme was also likely to have contributed to the improvement in the vaccination rate, consistent with this being the most commonly cited reason for not vaccinating in the baseline survey. Interestingly, although JE outbreaks occur periodically, caregivers tended to have the attitude that there was a low risk of a child getting sick with JE, and the perceived risk was not associated with vaccination status. This might be because of the availability of vaccines in Shaanxi Province. Caregivers aged less than 25 years were less likely to have a child vaccinated. In addition, the results suggest that the probability of a child getting vaccinated decreased with the education level of caregivers. Although higher education is usually associated with higher immunization coverage in less-developed countries,13 this finding is well supported by published literature. The high level of education of Dutch parents was identified as one of the determinants of a negative attitude towards having their child vaccinated.14 Opstelten et al. also reported a higher prevalence of non-compliers with influenza and pneumococcal vaccination among highly educated elderly persons.15 Additionally, China has significant variations in development levels across provinces and prefectures. Baoji Prefecture is highly developed and has relatively higher income than other prefectures in Shaanxi Province. Therefore, educated caregivers may have negative attitudes similar to those in developed countries. A limitation of this study is that the regression analysis does not include the whole sample because caregivers who had not heard of a JE vaccine were excluded from answering the question on vaccination status. This would underestimate the effect of demographic variables. It is not possible to identify and quantify the components of the interventions that contributed to significant changes and improvement in KAP. A number of factors could have contributed because several aspects of the intervention [e.g. improving access to vaccine through monthly availability; providing vaccine free of charge; introducing information, education and communication (IEC) activities at both provider and community levels] were implemented simultaneously. Additionally, an economic variable, which was not captured in the survey, may be associated with vaccination status. The findings, however, highlight the importance of routine immunization and the necessity for IEC activities targeting young and educated caregivers to improve knowledge of disease and vaccination coverage. Efforts should be made to identify appropriate types of media and IEC messages to reach caregivers with different demographic profiles.
Ethical approval Ethical review committees at Chinese Centre for Disease Prevention and Control and PATH.
Funding PATH Japanese Encephalitis Project, which was funded by the Bill & Melinda Gates Foundation (Grant 28658).
Competing interests None declared.
83
Acknowledgements The authors are grateful for the contributions of staff at the Chinese CDC, Shaanxi Province CDC, Baoji Prefecture CDC, and county CDCs, Lixia Wang, Junfeng Yang, and the health staff and caregivers whose support and participation made this project successful. Special thanks go to Erin Kester for editing and manuscript preparation.
references
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