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1.
MMWR Morb Mortal Wkly Rep ; 68(48): 1112-1116, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31805034

RESUMO

In 2005, the World Health Organization (WHO) Western Pacific Region countries, including China, resolved to eliminate measles by 2012 or as soon as feasible thereafter (1). As of 2018, nine* of the 37 Western Pacific Region countries or areas† had eliminated§ measles. China's Measles Elimination Action Plan 2006-2012 included strengthening routine immunization; conducting measles risk assessments, followed by supplementary immunization activities (SIAs) with measles-containing vaccine (MCV) at national and subnational levels; strengthening surveillance and laboratory capacity; and investigating and responding to measles outbreaks. Most recently, progress toward measles elimination in China was described in a 2014 report documenting measles elimination efforts in China during 2008-2012 and a resurgence in 2013 (2). This report describes progress toward measles elimination in China during January 2013-June 2019.¶ Measles incidence per million persons decreased from 20.4 in 2013 to 2.8 in 2018; reported measles-related deaths decreased from 32 in 2015 to one in 2018 and no deaths in 2019 through June. Measles elimination in China can be achieved through strengthening the immunization program's existing strategy by ensuring sufficient vaccine supply; continuing to improve laboratory-supported surveillance, outbreak investigation and response; strengthening school entry vaccination record checks; vaccinating students who do not have documentation of receipt of 2 doses of measles-rubella vaccine; and vaccinating health care professionals and other adults at risk for measles.


Assuntos
Erradicação de Doenças , Surtos de Doenças/prevenção & controle , Sarampo/prevenção & controle , Vigilância da População , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Feminino , Humanos , Programas de Imunização , Incidência , Lactente , Masculino , Sarampo/epidemiologia , Sarampo/mortalidade , Vacina contra Sarampo/administração & dosagem
3.
Int J Epidemiol ; 48(4): 1240-1251, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30977801

RESUMO

BACKGROUND: Measles is among the most highly infectious human diseases. By virtue of increasingly effective childhood vaccination, together with targeted supplemental immunization activities (SIAs), health authorities in the People's Republic of China have reduced measles' reproduction number from about 18 to 2.3. Despite substantial residual susceptibility among young adults, more in some locales than others, sustained routine childhood immunization likely would eliminate measles eventually. To support global eradication efforts, as well as expedite morbidity and mortality reductions in China, we evaluated alternative SIAs via mechanistic mathematical modelling. METHODS: Our model Chinese population is stratified by immune status (susceptible to measles infection; infected, but not yet infectious; infectious; and recovered or immunized), age (0, 1-4, 5-9, …, 65+ years) and location (31 provinces). Contacts between sub-populations are either empirical or a mixture of preferential and proportionate with respect to age and decline exponentially with distance between locations at age-dependent rates. We estimated initial conditions and most parameters from recent cross-sectional serological surveys, disease surveillance and demographic observations. Then we calculated the reproduction numbers and gradient of the effective number with respect to age- and location-specific immunization rates. We corroborated these analytical results by simulating adolescent and young adult SIAs using a version of our model in which the age-specific contact rates vary seasonally. RESULTS: Whereas the gradient indicates that vaccinating young adults generally is the optimal strategy, simulations indicate that a catch-up campaign among susceptible adolescent schoolchildren would accelerate elimination, with timing dependent on uptake. CONCLUSIONS: These results are largely due to indirect effects (i.e. fewer infections than immunized people might otherwise cause), which meta-population models with realistic mixing are uniquely capable of reproducing accurately.

4.
Vaccine ; 36(52): 8131-8137, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30497834

RESUMO

BACKGROUND: China's immunization program is one of the oldest and largest in the world. Rates of vaccine-preventable diseases (VPD) are comparable to those in high-income countries. The program's evolution has been characterized by ambitious target setting and innovative strategies that have not been widely described. METHODS: We reviewed national and provincial health department archives; analyzed disease surveillance, vaccination coverage, and serosurvey data from 1950 through 2016; and, conducted in-depth interviews with senior Chinese experts involved early VPD control efforts. RESULTS: Widespread immunization began in the 1950s with smallpox, diphtheria, and Bacillus-Calmette Guerin vaccines, and in the 1960s with pertussis, tetanus, polio, measles, and Japanese encephalitis (JE) vaccines. The largest drops in absolute VPD burden occurred in the 1970s with establishment of the Rural Cooperative Medical System and a cadre of trained peasant health workers whose responsibilities included vaccinations. From 1970 to 1979, incidence per 100,000 population dropped 48% from 3.3 to 1.75 for diphtheria, 50% from 152.2 to 49.4 for pertussis, 77% from 2.5 to 0.6 for polio, 60% from 450.5 to 178.3 for measles, and 72% from 18.0 to 5.1 for JE, averting an average of 4 million VPD cases each year. Until the early 1980s, vaccines were delivered through annual winter campaigns using a coordinated 'rush-relay' system to expedite transport while leveraging vaccine thermostability. Establishment of the cold chain system during in the 1980s allowed bi-monthly vaccination rounds and more timely vaccination resulting in rates of diphtheria, pertussis, measles and meningitis falling over 90% from 1980 to 1989, while polio and JE rates fell 40-50%. In the 1990s, progress stalled as financing for public health was weakened by broad market reforms. Large investments in public health and immunizations by the central government since 2004 has led to further declines in VPD burden and increased equity. During 2011-2016, the incidence per 100,000 population was <2.0 for measles and <0.2 for pertussis, JE, meningococcal meningitis, and hepatitis A. From 1992 to 2014, the prevalence of chronic hepatitis B infection in children <5 years fell from 9.7% to 0.3%, a 97% decline. China was certified polio-free in 2000 and diphtheria was last reported in 2006. CONCLUSIONS: Long-term political commitment to immunizations as a basic right, ambitious targets, use of disease incidence as the primary metric to assess program performance, and nationwide scale-up of successful locally developed strategies that optimized use of available limited resources have been critical to China's success in controlling vaccine-preventable diseases.


Assuntos
Controle de Doenças Transmissíveis/história , Programas de Imunização/história , Cobertura Vacinal/estatística & dados numéricos , Criança , Pré-Escolar , China , Controle de Doenças Transmissíveis/estatística & dados numéricos , Assistência à Saúde , Hepatite B/prevenção & controle , História do Século XX , História do Século XXI , Humanos , Meningite Meningocócica/prevenção & controle , Poliomielite/prevenção & controle
5.
Vaccine ; 36(16): 2079-2085, 2018 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-29550193

RESUMO

BACKGROUND: Rubella-containing vaccine (RCV) became available in China in 1993 and was introduced nationwide into the Expanded Immunization Program (EPI) in 2008. We evaluated implementation and impact of RCV from 2 years prior to nationwide introduction through the 10 years after nationwide introduction. METHODS: We analyzed RCV lot-release (doses distributed) data, 1- and 2-dose RCV coverage, and rubella data from China's nationwide disease surveillance system to describe the current status and changes in rubella epidemiology between 2005 and 2017. RESULTS: While the vaccine was included into the routine immunization program in 2008, its full implementation required 4 years due to sporadic vaccine supply constraints. RCV1 and RCV2 coverage increased from 51.5% and 39.0% in 2008 to >95% during 2012 through 2016. From 2005 to 2017, the annual incidences (per million) of rubella ranged from 91.09 in 2008 down to 1.16 in 2017; reductions occurred in all age groups. The proportion of cases among individuals ≥20 years old increased from 0.97% in 2005 to 31.2% in 2017. In the better-developed eastern China, most cases were among adults; in central and western China, most cases were among children or adolescents. CONCLUSIONS: The marked decrease rubella was a result of inclusion of RCVs into EPI targeting children less than 2 years of age and achieving high level of 2-dose coverage. Rubella was reduced in absolute terms, and its epidemiology was changed to older cases with substantial inter-province variation. Ensuring full vaccination of school children and identifying strategies to reach adults with measles and rubella combined vaccines will be important to hasten elimination of rubella and prevent CRS outbreaks.


Assuntos
Erradicação de Doenças , Vacina contra Rubéola/imunologia , Rubéola (Sarampo Alemão)/epidemiologia , Rubéola (Sarampo Alemão)/prevenção & controle , Vacinação , China/epidemiologia , Feminino , História do Século XXI , Humanos , Programas de Imunização , Masculino , Vigilância da População , Rubéola (Sarampo Alemão)/história , Vacina contra Rubéola/administração & dosagem , Cobertura Vacinal
6.
Vaccine ; 36(17): 2307-2313, 2018 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-29567035

RESUMO

BACKGROUND: Hepatitis B virus (HBV) can cause chronic HBV infection, which may lead to advanced cirrhosis and liver cancer. Healthcare workers (HCWs) are at risk HBV infection as an occupational hazard. Hepatitis B vaccination of HCWs is recommended by WHO, but the status of hepatitis B vaccination among HCWs in China is seldom reported. METHODOLOGY: We conducted a cross-sectional study in 22 hospitals of 3 developed cities in China. We interviewed managers in infectious diseases and occupational health departments, and at least 40 HCWs per hospital. RESULTS: We interviewed 929 HCWs; 80.8% were vaccinated against hepatitis B and 96.7% were willing to be vaccinated; 38.2% of HCWs reported having at least one needle stick or sharps injury. Three hospitals provide free hepatitis B vaccination for HCWs; hospitals with a hepatitis B vaccination policy, more HCWs reported being vaccinated (91.7% vs 79.0%, P < 0.001). HCWs in high risk departments (P = 0.011), with more knowledge of hepatitis B vaccine (P < 0.001), and with fewer working years (P = 0.002) were more likely to be vaccinated against HBV. Infectious diseases and occupational health managers had positive attitudes towards hepatitis B vaccination. CONCLUSIONS: Hepatitis B vaccination was well accepted among HCWs. Hospital provision of free vaccine, greater HCW knowledge of HBV, and working in higher-risk settings were associated with being vaccinated. A national policy of offering hepatitis B vaccine to HCWs should be considered in China. Provision of free hepatitis B vaccine for HBsAb negative HCWs may be acceptable. Education about HBV and hepatitis B vaccine may help promote policy implementation.


Assuntos
Pessoal de Saúde/estatística & dados numéricos , Vacinas contra Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Hepatite B/imunologia , Hepatite B/prevenção & controle , Vacinação/estatística & dados numéricos , Adolescente , Adulto , China , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Anticorpos Anti-Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/prevenção & controle , Inquéritos e Questionários , Adulto Jovem
7.
BMC Infect Dis ; 18(1): 36, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29329528

RESUMO

BACKGROUND: As China approaches the elimination of measles, outbreaks of measles continue to occur. Healthcare workers (HCWs) are known to be at high risk of infection and transmission of measles virus. A measles outbreak occurred in a hospital in Xinjiang Uighur Autonomous Region of the People's Republic of China. We report an investigation of this outbreak and its implications for measles elimination and outbreak preparedness. METHODS: We conducted a retrospective search for measles cases using hospital records. Information on cases was collected by interview, and was used to determine epidemiological linkages. We surveyed HCWs to determine their demographic characteristics, disease history and vaccination status, and knowledge about measles. RESULTS: We identified 19 cases, ages 18 to 45 years, in Hospital W between December 2015 and January 2016; 14 were laboratory-confirmed, and 5 were epidemiologically linked. The primary case was a 25-year-old neurology department nurse who developed a rash on 22 December 2015 that was reported on 11 January 2016. She continued working and living with her workmates in a dormitory during her measles transmission period. Among the 19 infected HCWs, 2 had received a dose of measles-containing vaccine (MCV) before the outbreak, and 16 had unknown vaccination status. Outbreak response immunization activities were started on 8 January in a non-selective manner by offering vaccine regardless of vaccination history; 605(68%) of 890 HCWs were vaccinated. The HCW survey had a 73% response rate (646/890); 41% of HCWs reported that they had received MCV before outbreak, and 56% exhibited good knowledge of measles symptoms, transmission, complications, and vaccination. CONCLUSIONS: Low MCV coverage, low measles knowledge among HCWs, delayed reporting of measles cases, and absence of proper case management were associated with this outbreak. Training and vaccinating HCWs against measles are essential activities to prevent measles virus transmission among HCWs.


Assuntos
Pessoal de Saúde , Sarampo/transmissão , Adulto , China/epidemiologia , Surtos de Doenças , Exantema/virologia , Feminino , Hospitais , Habitação , Humanos , Masculino , Sarampo/epidemiologia , Vacina contra Sarampo/administração & dosagem , Pessoa de Meia-Idade , Doenças Profissionais/epidemiologia , Estudos Retrospectivos , Vacinação/estatística & dados numéricos , Adulto Jovem
8.
Hum Vaccin Immunother ; 14(6): 1392-1397, 2018 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-29377772

RESUMO

INTRODUCTION: China has used 3 different mumps-containing vaccines (MuCV) since 1990: monovalent mumps vaccine, measles-mumps (MM) vaccine, and measles-mumps-rubella (MMR) vaccine, and one dose MuCV (using MMR at 18 months) has been included in the EPI since 2007. MuCV effectiveness has been of concern following large-scale mumps outbreaks. In 2015, an outbreak of mumps occurred in a primary school, which allow us assess vaccine effectiveness of different MuCVs. METHOD: All children in the school were studied as a retrospective cohort. Vaccination histories and case information were obtained from vaccination records and clinic/hospital logs. Parental questionnaires were used to confirm students' illnesses and calculate attack rate (AR). VE was assessed using the formula, VE = (AR in unvaccinated students- AR in the vaccinated students) / (AR in unvaccinated students). VEs of different type of MuCV were compared. RESULTS: In total, 283 students were identified as clinical mumps among the 2370 students, and 1908 students were included for MuCV VE assessment. 213 (including 21 [8.9%] patients) were 2-dose MuCV recipients (AR: 9.9%), 1165 (including 123 [51.9%] patients) were 1-dose recipients (AR: 10.6%), and 530 (including 93 [39.2%] patients) were unvaccinated (AR: 17.5%). VE was 44% for 2 doses and 40% for one dose. For one-MuCV-dose students, estimated mumps VE was 63% for vaccinated within 3 years (between vaccination and this outbreak); 50% for vaccinated within 3 to 5 years; and 34% for vaccinated more than 5 years. Comparing VE by vaccine type and 5-year interval since vaccination, VE for MMR was 60%, which was consistently higher than VE for monovalent mumps vaccine (22%) and MM (2%). CONCLUSION: This outbreak was associated with low and declining 1-dose MuCV effectiveness. China's immunization program should evaluate the potential of a 2-dose MMR schedule to adequately control mumps.


Assuntos
Surtos de Doenças , Transmissão de Doença Infecciosa/prevenção & controle , Esquemas de Imunização , Vacina contra Caxumba/administração & dosagem , Vacina contra Caxumba/imunologia , Caxumba/epidemiologia , Caxumba/prevenção & controle , Adolescente , Criança , China/epidemiologia , Feminino , Humanos , Masculino , Estudos Retrospectivos , Inquéritos e Questionários , Resultado do Tratamento
9.
BMC Infect Dis ; 17(1): 742, 2017 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-29197328

RESUMO

BACKGROUND: The goal of polio eradication is to complete elimination and containment of all wild, vaccine-related and Sabin polioviruses. Vaccine-derived poliovirus (VDPV) surveillance in China from 2001-2013 is summarized in this report, which has important implications for the global polio eradication initiative. METHODS: Acute flaccid paralysis (AFP) cases and their contacts with VDPVs isolated from fecal specimens were identified in our AFP surveillance system or by field investigation. Epidemiological and laboratory information for these children were analyzed and the reasons for the VDPV outbreak was explored. RESULTS: VDPVs were isolated from a total of 49 children in more than two-thirds of Chinese provinces from 2001-2013, including 15 VDPV cases, 15 non-polio AFP cases and 19 contacts of AFP cases or healthy subjects. A total of 3 circulating VDPVs (cVDPVs) outbreaks were reported in China, resulting in 6 cVDPVs cases who had not been vaccinated with oral attenuated poliomyelitis vaccine. Among the 4 immunodeficiency-associated VDPVs (iVDPVs) cases, the longest duration of virus excretion was about 20 months. In addition, one imported VDPV case from Myanmar was detected in Yunnan Province. CONCLUSIONS: Until all wild, vaccine-related and Sabin polioviruses are eradicated in the world, high quality routine immunization and sensitive AFP surveillance should be maintained, focusing efforts on underserved populations in high risk areas.


Assuntos
Erradicação de Doenças , Paralisia/epidemiologia , Paralisia/virologia , Vacinas contra Poliovirus/imunologia , Anticorpos Antivirais/sangue , Criança , Pré-Escolar , China/epidemiologia , Feminino , Voluntários Saudáveis , Humanos , Lactente , Masculino , Mianmar , Poliomielite/epidemiologia , Poliomielite/prevenção & controle , Poliovirus/imunologia , Vacina Antipólio Oral/uso terapêutico , Vacinas contra Poliovirus/uso terapêutico , Fatores de Tempo , Cobertura Vacinal
10.
Pak J Pharm Sci ; 30(4): 1383-1388, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29039342

RESUMO

Dioscorea opposita is an edible and medicinal plant available in many areas of China. This study aimed to assess in vitro immune potentials of a water-soluble polysaccharide extract from D. opposita planted in Henan Province, China. In vitro effects of the extract on three immune cells (macrophages, natural killer cells and splenocytes) from mice and secretion of eight immune-related molecules in macrophages and splenocytes were evaluated. In total, the extract exhibited a dose-dependent manner on these immunological responses. The extract at dose level of 50µg/ml enhanced respective splenocyte proliferation, macrophage phagocytosis, and natural killer cell activity by 150%, 18% and 47%, increased secretion of interleukin-2 and interferon-γ (from 41.4 and 24.6 pg/ml to 48.8 and 91.5 pg/ml, respectively) but decreased secretion of interleukin-4 (from 38.9 to 27.9 pg/ml) in splenocytes. The extract at the same dose level also stimulated inducible nitric oxide synthase and lysozyme in macrophages, and enhanced secretion of interleukin-6, interleukin-1ß and tumor necrosis factor-α (from 26.6, 73.4 and 39.6 pg/ml to 60.2, 131.0 and 144.7 pg/ml, respectively). It is concluded that water-soluble polysaccharides from D. opposita have immune potentials to the body, via activating immune cells and regulating the secretion of immune-related molecules.


Assuntos
Dioscorea/química , Extratos Vegetais/farmacologia , Polissacarídeos/química , Animais , Biomarcadores/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , China , Relação Dose-Resposta a Droga , Feminino , Células Matadoras Naturais/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Fagocitose/efeitos dos fármacos , Extratos Vegetais/química , Baço/metabolismo
11.
PLoS Med ; 14(4): e1002255, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28376084

RESUMO

BACKGROUND: Industrialization and demographic transition generate nonstationary dynamics in human populations that can affect the transmission and persistence of infectious diseases. Decades of increasing vaccination and development have led to dramatic declines in the global burden of measles, but the virus remains persistent in much of the world. Here we show that a combination of demographic transition, as a result of declining birth rates, and reduced measles prevalence, due to improved vaccination, has shifted the age distribution of susceptibility to measles throughout China. METHODS AND FINDINGS: We fit a novel time-varying catalytic model to three decades of age-specific measles case reporting in six provinces in China to quantify the change in the age-specific force of infection for measles virus over time. We further quantified the impact of supplemental vaccination campaigns on the reduction of susceptible individuals. The force of infection of measles has declined dramatically (90%-97% reduction in transmission rate) in three industrialized eastern provinces during the last decade, driving a concomitant increase in both the relative proportion and absolute number of adult cases, while three central and western provinces exhibited dynamics consistent with endemic persistence (24%-73% reduction in transmission rate). The reduction in susceptible individuals due to supplemental vaccination campaigns is frequently below the nominal campaign coverage, likely because campaigns necessarily vaccinate those who may already be immune. The impact of these campaigns has significantly improved over time: campaigns prior to 2005 were estimated to have achieved less than 50% reductions in the proportion susceptible in the target age classes, but campaigns from 2005 onwards reduced the susceptible proportion by 32%-87%. A limitation of this study is that it relies on case surveillance, and thus inference may be biased by age-specific variation in measles reporting. CONCLUSIONS: The age distribution of measles cases changes in response to both demographic and vaccination processes. Combining both processes in a novel catalytic model, we illustrate that age-specific incidence patterns reveal regional differences in the progress to measles elimination and the impact of vaccination controls in China. The shift in the age distribution of measles susceptibility in response to demographic and vaccination processes emphasizes the importance of progressive control strategies and measures to evaluate program success that anticipate and react to this transition in observed incidence.


Assuntos
Sarampo/epidemiologia , Modelos Teóricos , Dinâmica Populacional , Adulto , Distribuição por Idade , Criança , China/epidemiologia , Humanos , Incidência , Sarampo/prevenção & controle , Sarampo/transmissão , Vacina contra Sarampo/uso terapêutico , Vacinação/estatística & dados numéricos
13.
Vaccine ; 34(51): 6539-6544, 2016 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-27329182

RESUMO

INTRODUCTION: Following implementation of China's 2006-2012 Action Plan for measles elimination, which led to a nadir of measles in 2012, a resurgence started in 2013 that continued into 2014. Measles typically is a disease that mainly affects children. We investigated a community outbreak in 2014 with measles virus transmission among adults without children serving as virus reservoirs. Our investigation highlights adult susceptibility to measles. METHODS: We conducted a retrospective active case search, and analyzed confirmed case data to describe person, place, and time characteristics of the outbreak. All individuals with measles with onset during the first 2 months of the outbreak were interviewed face-to-face to determine source(s) of infection and transmission route (from whom and to whom). RESULTS: Among the 280 cases, 220 (77.6%) were among ≥20-year-old adults, 24 (8.6%) were among 8-23 month olds, 22 (7.9%) were among <8-month-old infants, and the remaining 14 (5.9%) were among 2-19 year olds. Of the 83 cases in the early stage of the outbreak, 41 (49.4%) were acquired in the community, 24 (28.9%) were acquired nosocomially, 13 (15.7%) were acquired by family contact, and 5 were imported. Among 44 clearly determined transmission linkages, 37 (84.1%) were adult to other age-group (these include 29 adult-to-adult, seven adult-to-child, and one adult-to-infant), six were from infants to adult and children, and one was child-to-child. Outbreak response immunization activities were implemented by non-selective supplementary immunization activities, with 51.3% of targeted 5-19-year-old children and adolescents, and 30.2% of targeted 20-49-year-old adults being vaccinated. CONCLUSIONS: Despite high population immunity among children and adolescents following three rounds of measles vaccine supplementary immunization activities, sustained measles virus transmission still occurred among adults in this community. Adult measles immunity gaps might threaten measles elimination, highlighting the importance targeting susceptible adults during outbreak response immunization.


Assuntos
Surtos de Doenças , Transmissão de Doença Infecciosa , Sarampo/epidemiologia , Sarampo/transmissão , Adolescente , Adulto , Criança , Pré-Escolar , China/epidemiologia , Reservatórios de Doenças , Suscetibilidade a Doenças , Feminino , Humanos , Lactente , Recém-Nascido , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
14.
Int J Epidemiol ; 45(2): 441-9, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-27174834

RESUMO

BACKGROUND: China reduced hepatitis B virus (HBV) infection by 90% among children under 5 years old with safe and effective hepatitis B vaccines (HepB). In December 2013, this success was threatened by widespread media reports of infant deaths following HepB administration. Seventeen deaths and one case of anaphylactic shock following HBV vaccination had been reported. METHODS: We conducted a telephone survey to measure parental confidence in HepB in eleven provinces at four points in time; reviewed maternal HBV status and use of HepB for newborns in birth hospitals in eight provinces before and after the event; and monitored coverage with hepatitis B vaccine and other programme vaccines in ten provinces. RESULTS: HepB from the implicated company was suspended during the investigation, which showed that the deaths were not caused by HepB vaccination. Before the event, 85% respondents regarded domestic vaccines as safe, decreasing to 26.7% during the event. During the height of the crisis, 30% of parents reported being hesitant to vaccinate and 18.4% reported they would refuse HepB. Use of HepB in the monitored provinces decreased by 18.6%, from 53 653 doses the week before the event to 43 688 doses during the week that Biokangtai HepB was suspended. Use of HepB within the first day of life decreased by 10% among infants born to HBsAg-negative mothers, and by 6% among infants born to HBsAg-positive mothers. Vaccine refusal and HepB birth dose rates returned to baseline within 2 months; confidence increased, but remained below baseline. CONCLUSIONS: The HBV vaccine event resulted in the suspension of a safe vaccine, which was associated with a decline of parental confidence, and refusal of vaccination. Suspension of a vaccine can lead to loss of confidence that is difficult to recover. Timely and credible investigation, accompanied by proactive outreach to stakeholders and the media, may help mitigate negative impact of future coincidental adverse events following immunization.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/mortalidade , Vacinas contra Hepatite B/efeitos adversos , Hepatite B/prevenção & controle , Programas de Imunização , Morte do Lactente , Vacinação , Sistemas de Notificação de Reações Adversas a Medicamentos , Causas de Morte , Criança , China/epidemiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etnologia , Feminino , Hepatite B/diagnóstico , Hepatite B/etnologia , Anticorpos Anti-Hepatite B/administração & dosagem , Anticorpos Anti-Hepatite B/efeitos adversos , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/imunologia , Humanos , Lactente , Recém-Nascido , Masculino , Meios de Comunicação de Massa , Inquéritos e Questionários , Vacinação/estatística & dados numéricos , Vacinação/tendências
15.
Vaccine ; 34(51): 6553-6560, 2016 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-27013438

RESUMO

INTRODUCTION: Endemic measles persists in China, despite >95% reported coverage of two measles-containing vaccine doses and nationwide campaign that vaccinated more than 100 million children in 2010. We performed a case-control study in six Chinese provinces during January 2012 through June 2013 to identify risk factors for measles infection among children aged 0-7 months. METHODS: Children with laboratory-confirmed measles were neighborhood matched with three controls. We interviewed parents of case and control infants on potential risk factors for measles. Adjusted matched odds ratios (mOR) and 95% confidence intervals (CIs) were calculated by multivariable conditional logistic modeling. We calculated attributable fractions for risk factors that could be interpreted as causal. RESULTS: Eight hundred thirty cases and 2303 controls were enrolled. In multivariable analysis, male sex (mOR 1.6 [1.3, 2.0]), age 5-7 months (mOR 3.9 [3.0, 5.1]), migration between counties (mOR 2.3 [1.6, 3.4]), outpatient hospital visits (mOR 9.4 [6.6, 13.3]) and inpatient hospitalization (mOR 107.1 [48.8, 235.1]) were significant risk factors. The calculated attributable fractions for hospital visits was 43.1% (95% CI: 40.1, 47.5%) adjusted for age, sex and migration. CONCLUSIONS: Hospital visitation was the largest risk factor for measles infection in infants. Improved hospital infection control practices would accelerate measles elimination in China.


Assuntos
Sarampo/epidemiologia , Estudos de Casos e Controles , China/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fatores de Risco
16.
Vaccine ; 34(51): 6545-6552, 2016 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-26876440

RESUMO

INTRODUCTION: Endemic measles persists in China, despite >95% reported coverage of two measles-containing vaccine doses and nationwide campaign that vaccinated more than 100 million children in 2010. In 2011, almost half of the 9943 measles cases in China occurred in children eligible for measles vaccination. We conducted a case-control study during 2012-2013 to identify risk factors for measles infection in children aged 8 months-14 years. METHODS: Children with laboratory-confirmed measles were age- and neighborhood-matched with three controls. We interviewed parents of case and control infants on potential risk factors for measles. We calculated adjusted matched odds ratios and 95% confidence intervals of risk factors. We calculated attributable fractions for risk factors that could be interpreted as causal and vaccine efficacy (VE) for the measles containing vaccine (MCV) used in the Chinese immunization program. RESULTS: In all, 969 case-patients and 2845 controls were enrolled. In multivariable analysis, lack of measles vaccination both overall (mOR 22.7 [16.6, 31.1] and when stratified by region (east region, mOR 74.2 [27.3, 202]; central/western regions mOR 17.4 [12.5, 24.3]), hospital exposure (mOR 63.0, 95% CI [32.8, 121]), and migration among counties (overall mOR 3.0 [2.3, 3.9]) were significant risk factors. The calculated VE was 91.9-96.1% for a single dose of MCV and 96.6-99.5% for 2 doses. CONCLUSIONS: Lack of vaccination was the leading risk factor for measles infection, especially in children born since the 2010 supplementary immunization activity. Reducing missed vaccination opportunities, improving immunization access for migrant children, and strengthening school/kindergarten vaccine checks are needed to strengthen the routine immunization program and maintain progress toward measles elimination in China.


Assuntos
Vacina contra Sarampo/administração & dosagem , Sarampo/epidemiologia , Sarampo/prevenção & controle , Vacinação/estatística & dados numéricos , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Lactente , Masculino , Fatores de Risco
17.
PLoS One ; 10(7): e0133983, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26208216

RESUMO

BACKGROUND: A measles outbreak occurred in a western county of China in 2013, the year after China's historic nadir of measles. We conducted a field investigation to identify gaps in measles vaccination coverage and immunization program weaknesses, and to provide recommendations for measles outbreak response and immunization program improvement. METHODS: We analyzed surveillance data from 2008 to 2013 to describe the measles epidemiology of the county. Measles-containing vaccine coverage was estimated using two methods: previously-reported administrative coverage and an estimation of coverage by clinic-kept vaccination records (n = 542). We conducted a rapid field coverage assessment in a migrant population village to evaluate coverage after emergency vaccination. We conducted a review of hospital records of measles cases to address the role hospital transmission played during the early stage of this outbreak. RESULTS: There were 153 cases in the outbreak, primarily among children too young to vaccinate, unvaccinated children less than 3 years old, and adults. Measles-containing vaccine coverage by the field assessment showed that 20% of children aged 8-17 months had zero doses, and 9% of ≥2 years old children had fewer than two doses. The vaccination statuses of all adult cases were either zero doses or unknown. At least 61% of cases had been hospitalized. The proportion of cases who had been hospital-exposed 7 to 21 days prior to rash onset decreased from 52% to 22% after hospitals strengthen their isolation measures. CONCLUSIONS: This outbreak was a result of measles vaccination coverage gaps among young children and adults, and insufficient hospital isolation of cases. The lower coverage seen in the field estimation compared with reported coverage showed that reported coverage could have been overestimated. Hospitals were sites of transmission in the early stage of the outbreak. A strict hospital isolation policy could decrease spread of measles. Emergency vaccination was associated with stopping measles transmission in low coverage areas.


Assuntos
Surtos de Doenças , Vacina contra Sarampo , Sarampo/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , China , Feminino , História do Século XXI , Hospitalização , Humanos , Lactente , Recém-Nascido , Masculino , Sarampo/história , Sarampo/prevenção & controle , Sarampo/transmissão , Vacina contra Sarampo/imunologia , Vigilância da População , Estações do Ano , Vacinação , Adulto Jovem
18.
Pediatrics ; 135(4): e1032-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25733758

RESUMO

In July 2013, the National Immunization Program of China was notified by the US Centers for Disease Control and Prevention that measles was detected in 3 newly adopted, special needs children with cerebral palsy (CP) from China. We report an investigation of measles transmission in China that led to infection of these children. Interviews were conducted with welfare institute staff and panel physicians; health records of the potentially exposed population were reviewed; and immunization coverage was assessed among institute residents. Five residents with CP, all unvaccinated against measles, among who were the 3 adoptees, were linked epidemiologically into 3 generations of measles transmission antecedent to the US outbreak. In a random sample of residents, first dose of measles containing vaccine (MCV1) and MCV2 coverage was 16 of 17 (94%) and 7 of 11 (64%) among children with CP, and 100% (32 of 32) and 96% (21 of 22) among children without CP. Vaccinators reported reluctance to vaccinate children with CP because the China pharmacopeia lists encephalopathy as a contraindication to vaccination. Panel physicians reported to investigators no necessity of vaccination for adoptees to the United States if US parents sign an affidavit exempting the child from vaccination. We recommend that the China pharmacopeia vaccine contraindications be reviewed and updated, the United States should reconsider allowing vaccination exemptions for internationally adopted children unless there are true medical contraindications to vaccination, and US pediatricians should counsel adopting parents to ensure that their child is up-to-date on recommended vaccinations before coming to the United States.


Assuntos
Adoção , Grupo com Ancestrais do Continente Asiático/estatística & dados numéricos , Paralisia Cerebral/epidemiologia , Surtos de Doenças , Sarampo/epidemiologia , Sarampo/transmissão , Lesões Encefálicas/epidemiologia , Lesões Encefálicas/etnologia , Paralisia Cerebral/etnologia , Criança , Pré-Escolar , China/etnologia , Estudos Transversais , Feminino , Humanos , Programas de Imunização , Lactente , Masculino , Sarampo/etnologia , Sarampo/prevenção & controle , Vacina contra Sarampo/administração & dosagem , Centros de Reabilitação/estatística & dados numéricos , Estados Unidos
19.
BMC Infect Dis ; 15: 23, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25608672

RESUMO

BACKGROUND: China is approaching measles elimination, but indigenous measles still circulates. County L in China has reported measles-containing vaccine (MCV) coverage rates >95% since 2000. Despite high reported coverage, a large measles outbreak occurred among young children in L County. We measured MCV coverage using 5 different methods during an investigation on this outbreak and compared our estimates with reported rates. METHODS: Reported coverage rates are determined by aggregating clinic-based data across the county: doses administered in each clinic divided by the number of children registered in each clinic. Our methods estimated coverage for the 2010-2012 birth cohort, and were (1) administrative method: doses administered in clinics divided by the birth cohort recorded in the Statistical Year Book, (2) house-to-house convenience-sample survey of children living near cases, (3) vaccination clinic records review, (4) determination of a convenience sample of measles outbreak cases' vaccination statuses and using the field vaccine efficacy outbreak equation to estimate population coverage, and (5) a seroprevalence survey using a convenience sample of residual blood samples from hospitals. RESULTS: The measles outbreak totaled 215 cases, representing an incidence of 195.8 per million population. Our estimated MCV coverage rates were: (1) administrative method: 84.1%-87.0% for MCV1 and 80.3%-90.0% for MCV2, (2) in-house survey: 83.3% of 9-17 month children received MCV1, and 74.5% of 24-47 month children received MCV2, (3) clinic record review: 85.5% of 9-17 month children received MCV1, and 73.2% of 24-59 month children received MCV2, (4) field VE method: 83.6% of 9-47 month children received one or more MCV doses, and (5) serology: seropositive rates were <80% in the 12-17 and 18-23 month age cohorts. CONCLUSIONS: Compared with reported coverage >95%, our 5 coverage assessments all showed substantially lower coverage. China should evaluate guidelines for reporting vaccination coverage and identify feasible improvements to the assessment methods.


Assuntos
Surtos de Doenças/prevenção & controle , Vacina contra Sarampo/administração & dosagem , Sarampo/epidemiologia , Vacinação/estatística & dados numéricos , Adolescente , Criança , Serviços de Saúde da Criança , Pré-Escolar , China/epidemiologia , Feminino , Promoção da Saúde , Humanos , Lactente , Masculino , Sarampo/prevenção & controle , Estudos Soroepidemiológicos
20.
PLoS One ; 9(12): e113880, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25503964

RESUMO

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.


Assuntos
Surtos de Doenças , Imunização/estatística & dados numéricos , Poliomielite/epidemiologia , Poliomielite/prevenção & controle , Vacinas contra Poliovirus/imunologia , Poliovirus/imunologia , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Surtos de Doenças/prevenção & controle , Feminino , Humanos , Lactente , Masculino , Paralisia/epidemiologia , Poliomielite/transmissão , Poliovirus/fisiologia
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