2018-2019年青海省脑炎脑膜炎症候群病例脑脊液病原学检测结果分析

目的通过对脑炎脑膜炎症候群脑脊液标本进行培养鉴定,以及应用荧光定量PCR检测细菌性脑膜炎病原体DNA进行分群,从而了解全省脑炎脑膜炎症候群病原流行特征及变异变迁规律。方法依据《脑炎脑膜炎症候群病原学监测技术方案》检测技术,对全省两家哨点医院脑炎脑膜炎症候群急性期病例的脑脊液标本174份进行病原学培养鉴定和核酸检测(培养阴性的标本做PCR检测)。结果 2018-2019共检测脑炎脑膜炎症候群脑脊液标本174份,经培养鉴定:有菌生长16份,其中目标菌检出3株,其它菌13株。158份脑脊液培养检测结果阴性的标本做荧光定量PCR检测,脑炎奈瑟菌和肺炎链球菌均为阴性,检出流感嗜血杆菌6份。结论青海省两家哨点医院脑炎脑膜炎标本病原体检出率比较低。荧光定量PCR可用于细菌性脑炎脑膜炎病原体的检测、鉴别分群,可为临床提供科学的诊断依据。     

南宁市邕宁区2011～2012年手足口病病原学检测结果分析

目的：了解南宁市邕宁区手足口病病原的分布特征和优势流行病原,分析肠道病毒血清型变化,为手足口病预防控制提供科学依据.方法：对2011～2012年哨点医院首次就诊临床诊断的手足口病病例进行标本采集和流行病学个案调查,采用Real-time RT-PCR法对标本进行肠道病毒核酸检测.结果：合计检测临床标本132例,阳性标本113例,总阳性率为85.61％.其中2011年阳性率为89.71％,优势病原株是CoxA16型,占73.77％;2012年阳性率为81.25％,优势病原株以EV71型和其他肠道病毒为主,分别占40.38％和57.69％.患病儿童以1～3岁儿童为主,占77.27％.结论：南宁市邕宁区2011年手足口病优势病原株是CoxA16型,2012年以EV71型和其他肠道病毒为主,EV71型是引起重症病例的优势病原株.     

绵阳市2009-2011年手足口病监测结果分析

目的了解绵阳市手足口病的流行病学特征和病原学型别及变化规律,为科学制订预防和控制策略提供依据。方法对2009-2011年中国疾病监测信息报告管理系统统计的绵阳市手足口病病例进行流行病学分析、对送检的咽拭子标本采用实时荧光PCR(RT-PCR)法进行EV71、CoxA16及其他肠道病毒的核酸检测。结果病原学检测结果:2009年检测标本159例,阳性标本90例,阳性率56.60%,病原优势株为EV71型,占95.56%;2010年检测标本198例,阳性标本110例,阳性率55.56%,病原优势株为CoxA16型,占87.27%;2011年检测标本241例,阳性标本138例,阳性率57.26%,病原优势株为EV71型,占92.75%。流行病学监测结果:2009年报告手足口病病例1422例,发病率26.82/10万;2010年报告手足口病病例2 348例,发病率44.19/10万;2011年共报告手足口病病例2963例,发病率62.20/10万。发病时间高峰在4～6月;发病年龄集中在1～3岁组,占75.69%;男性高于女性,男女比例为1.86∶1;发病的场所分布以散居儿童为主。结论绵阳市手足口发病发病率呈逐年上升趋势,病原的流行株以EV71和CoxA16为主,呈交替流行态势。因此,继续加强手足口健康知识教育、宣传和病例及病原学监测工作对于手足口病的科学防控具有重要意义。     

2009～2010年济宁市流行性感冒监测分析

目的了解甲型H1N1流感疫情变化,指导流感防控。方法对流感监测哨点医院报告的流感样病例（ILI）和辖区内报告的暴发疫情进行描述性分析,应用Realtime RT—PER对流感样病例进行流感病毒核酸检测,阳性标本应用MDCK细胞进行病毒分离。结果2009年6月～2010年3月4所流感监测哨点医院共报告门诊病例总数590590例,流感样病例12067例,ILI％为2．04。流感样病例病毒核酸检测阳性544份,其中甲型H1N1流感病毒阳性194份,季节性甲型流感病毒阳性248份,季节性乙型流感病毒阳性102份;细胞培养病毒分离血凝测定阳性143株,其中甲型H1N1流感病毒119株,季节性甲型流感病毒4株,季节性乙型Victoria流感病毒20株,各型流感病毒季节性消长趋势明显。流感样病例暴发疫情22起,病原检测18起流感病毒核酸阳性,其中7起季节性甲型流感、10起甲型H1N1流感和1起季节性甲、乙型流感混合感染。结论流感样病例数与病原学监测结果基本吻合,可以用来反映流感活动的强弱,监测网络的敏感性还有待于进一步提高。     

复合多聚酶链反应技术在流感嗜血杆菌和b型流感嗜血杆菌联合检测中的意义

目的 探讨复合多聚酶链反应（PCR）技术在流感嗜血杆菌（Hi)和b型流感嗜血杆菌（Hib)联合检测中的意义。方法 应用Hi种特异性引物和Hib型特异性引物混合的复合PCR对实验菌株和83份婴幼儿肺炎急性期痰标本和51份血标本、同期37份健康婴幼儿咽拭子标本及21份临床拟诊细菌性脑膜炎患儿和23份非细菌性脑膜炎患儿的脑脊液标本进行了检测。结果 复合PCR检测可同时鉴别Hib和非b型Hi,对Hib标准菌株检测的敏感性低限为10个菌体;肺炎患儿呼吸道标本的Hib阳性率（22．9％）明显高于健康儿童（0）、非b型Hi阳性率（10．5％）与健康儿童（16．2％）差别无显著性意义;51份血标本Hi阳性6份（11．8％）,均为Hib;21份细菌性脑膜炎脑脊液标本Hi阳性4份（19．0％）,均为Hib;23份非细菌性脑膜炎的脑脊液标本Hi均为阴性。结论 复合PCR可同时检测并鉴别Hib和非b型Hi,对Hib肺炎和肺膜炎具有一定的诊断价值。     

2011-2013年青海省传染病技术平台脑炎脑膜炎症候群监测结果分析

目的通过国家科技重大专项"传染病监测技术平台"项目,掌握了解青海省不同人群不同年龄和不同季节的脑炎脑膜炎症候群病原谱构成与流行特征,为疫情监控、临床病例的有效救治提供科学依据。方法依据"艾滋病和病毒性肝炎等重大传染病防治"科技重大专项传染病监测技术平台项目《脑炎脑膜炎症候群监测技术方案》采集两家哨点医院脑炎脑膜炎病例标本进行病原及流行病学分析。结果 258份脑脊液中检出病原菌17株,其中目标菌有3株,总阳性率为6.59%;病毒荧光PCR检测阳性12份,阳性率为4.65%。细菌、病毒无混合感染病例。病毒感染主要集中在0~15岁组。秋冬季病原微生物检出率高于春夏季,特别是肠道病毒在7~9月的阳性率达到了3.10%。结论青海省细菌性脑炎的优势菌已发生了重要变化,20世纪80年代后由于A群脑膜炎球菌疫苗的普遍应用,脑膜炎奈瑟菌引起的发病不断减少,从原有的脑膜炎奈瑟菌、肺炎链球菌、b型流感嗜血杆菌等改变为以葡萄球菌等为主要的致病菌;非脊灰肠道病毒成为无菌性脑炎的主要病原,并且具有明显的季节性和年龄分布。     

宜昌市2006-2015年急性脑炎及脑膜炎症候群病原谱分析

目的 分析宜昌市2006-2015年近10年急性脑炎/脑膜炎病例病原谱构成,为疾病防控提供依据.方法 对湖北省宜昌市6所监测医院符合监测病例定义的患者采集血液和(或)脑脊液标本,使用酶联免疫吸附试验(ELISA)和荧光定量PCR反应进行病原体检测,得出急性脑炎/脑膜炎病例病原谱构成,并进行统计学分析.结果 共采集血清标本1958份,脑脊液标本1867份.2504例病例开展乙脑病毒学检测,1545例病例开展其他四种病毒学检测,1867例病例开展细菌学检测.实验室确诊病毒性感染955例,肠道病毒、单纯疱疹病毒、腮腺炎病毒和乙脑病毒感染阳性率分别为20.84%、20.00%、17.02%和2.44%,;确诊细菌性感染52例,检测出的脑膜炎奈瑟菌、肺炎链球菌和b型流感嗜血杆菌阳性率分别为42.31%、42.31%和15.38%.时间分布上病毒性感染病例主要集中在5~8月份,占总数的55.92%;细菌性感染病例呈全年散发.人群分布上病毒性感染病例以<15岁青少年为主,细菌性感染病例以>15岁较大年龄组为主,分别占总数的51.83%和67.31%.性别分布上病毒性感染病例男女比为1.09:1;细菌性感染病例男女比为2.06:1.结论 肠道病毒和单纯疱疹病毒是引起宜昌市病毒性脑炎/脑膜炎的主要病原体;脑膜炎球菌和肺炎链球菌是引起宜昌市细菌性脑炎/脑膜炎的主要病原体,应该重点进行防控.     

湖北省宜昌市2016年急性脑炎与脑膜炎症候群监测分析

目的 分析2016年宜昌市各类急性脑炎、脑膜炎的流行特征,了解其病原谱及临床诊断符合性情况,为该症候群的疾病防控工作提供科学依据。方法 在湖北省宜昌市选取4家市级医院及2家县级医院作为监测哨点医院,进行急性脑炎和脑膜炎的病例监测,对监测病例进行流行病学调查以及血清和脑脊液标本的实验室检测。结果 总共监测病例201例,监测病例以大于45岁患者居多,春夏两季报告病例较多,以农民居多,实验室通过IgM抗体检测确诊的病毒性脑炎病原构成中,前三位分别为流行性腮腺炎病毒（28.1%）、科萨奇病毒（28.1%）和单纯疱疹病毒（25.0%）。细菌性病原构成主要是肺炎链球菌（50.0％）和金黄色葡萄球菌（33.3%）。结合临床诊断结果以及相关实验室诊断信息,在实际的临床诊断过程中,急性脑炎/脑膜炎的病例误诊概率相对较高。结论 春夏季应作为急性脑炎/脑膜炎防控的主要季节,高年龄组是脑炎脑膜炎需要高度关注的人群,开展早期病原学检测可以及时有效地诊断脑炎脑膜炎,同时可使该病症的治愈率提高,减少患者并发症。     

5岁以下儿童急性脑炎/脑膜炎病例特征与病原谱分析

目的了解5岁以下儿童急性脑炎/脑膜炎病例特征与病原谱。方法 2007-2016年在石家庄市6所县级及以上医院开展急性脑炎/脑膜炎症候群监测,包括现场流行病学监测与实验室监测两部分。前者是由县级疾控中心对医院报告脑炎/脑膜炎病例逐一进行流行病学个案调查;后者是由医院对采集的病例血标本和脑脊液标本进行临床常规检测和细菌培养,由各级疾控中心实验室采用RT-PCR方法进行细菌性和病毒性病原体检测、用ELISA进行病毒血清学检测。结果 10年共报告5岁以下儿童急性脑炎/脑膜炎病例1 695例,男女性别比为1.41∶1,平均年龄2.62岁,城乡比为1∶1.89,夏季为发病高峰。临床表现以高热(≥38℃)、呕吐、精神萎靡、头痛常见,体征相对不明显。EV 71病毒、肺炎链球菌、EV 71外的其他肠道病毒、乙型脑炎病毒、脑膜炎奈瑟氏菌位居病原谱前5位。结论 5岁以下儿童急性脑炎/脑膜炎病例临床特征越来越不典型,肠道病毒为首位优势病原体。     

肺炎链球菌流行病学特点、耐药现状及其对临床诊疗的影响

肺炎链球菌(Streptococcus pneumonia,Sp)为革兰阳性双球菌,一直是诸多疾病,如肺炎、细菌性脑膜炎、成人和儿童败血症以及儿童中耳炎的常见致病原.尽管各种抗生素和疫苗已经广泛使用,但其造成的疾病负担仍是巨大的[1-2].以肺炎为例,国际社区获得性肺炎(CAP)组织和我国的报告显示在可取得病原学检测结果的CAP患者中,32.6％～36％的病例确诊为Sp感染[2-3].国外报道的成人Sp肺炎菌血症病死率为10％ ～ 30％,Sp脑膜炎病死率为l6％～37％[4-5].现就Sp流行病学、耐药现状及其对临床诊疗相关的影响综述如下.     

合肥市小儿b型流感嗜血杆菌性脑膜炎的发病调查

目的了解合肥市小儿ｂ型流感嗜血杆菌（Ｈｉｂ）脑膜炎的流行情况。方法组成１３家医院的小儿化脓性脑膜炎协作组,收集合肥市１９９０～１９９２年３年的资料。监测所有临床诊断为急性细菌性脑膜炎的患儿,收集标本进行病原学研究。对脑脊液（ＣＳＦ）、血作常规细菌学检查,脑脊液、血和浓缩尿标本进行对流免疫电泳（ＣＩＥ）抗原检测,全部资料进行流行病学分析。结果３年中共有经临床确诊的小儿细菌性脑膜炎６０例,其中３１例（５１７％）Ｈｉｂ抗原阳性,而其中仅３例ＣＳＦ细菌培养出Ｈｉｂ。该市Ｈｉｂ脑膜炎年发病率１５岁以下儿童为４８１／１０万,５岁以下儿童为１０．６６／１０万,病死率为９７％,存活患儿２１４％留有精神和神经系统并发症和后遗症。结论用抗原检测结合细菌培养,可为９０％细菌性脑膜炎患儿作出病原学诊断。Ｈｉｂ是化脓性脑膜炎患儿中最常见的病原,但它的发病率较世界其它地区为低。     

Haemophilus influenzae meningitis in Manitoba and the Keewatin District, NWT: potential for mass vaccination.

A community-based surveillance study of all central nervous system infections was carried out in Manitoba and the Keewatin District, NWT, between Apr. 1, 1981, and Mar. 31, 1984. There were 201 cases of bacterial meningitis in Manitoba over the study period, 81 (40%) caused by Haemophilus influenzae; all but one isolate tested were type b (Hib). There were nine cases of H. influenzae meningitis in the Keewatin District. The overall annual incidence rate of H. influenzae meningitis in Manitoba was 2.5/100,000; for children under 5 years the rate was 32.1/100,000. For the Keewatin District the corresponding rates were 69.6/100,000 and 530/100,000. A total of 85% and 100% of the cases of H. influenzae meningitis occurred by 24 months of age in Manitoba and the Keewatin District respectively. The age at onset was earlier in native Indian children (22 cases) and Inuit children (9 cases) than in non-native children (59 cases) (p less than 0.005); thus, vaccine prevention of Hib meningitis will likely be more difficult in native Indian and Métis children. Without evaluating the increased potential of H. influenzae vaccines to prevent nonmeningitic forms of disease, we concluded that mass childhood vaccination with polyribosylribitolphosphate (PRP) vaccine is not warranted in Manitoba or the Keewatin District. Immunogenicity studies suggest that administration of conjugated Hib vaccines such as PRP-D in infancy may prevent approximately one-third to two-thirds of cases of H. influenzae meningitis; these vaccines warrant consideration for use in mass childhood vaccination programs.     

多重降落PCR检测痰标本肺炎链球菌与b型流感嗜血杆菌

目的:建立可同时检测痰标本中肺炎链球菌(Streptococcus pneumoniae,Sp)与b型流感嗜血杆菌(Hae-mophilus influenzae type b,Hib)的多重降落PCR。方法:以Sp cpsA基因、Hib capⅡ区为靶标设计引物,并用Primer-BLAST在线软件检测其特异性,多重降落PCR检测492份痰标本,并以标准菌株作为对照,结果与细菌培养法进行比较。结果:所建立的多重降落PCR对Sp、Hib的检测下限分别达6.3 pg、0.2 pg;与细菌培养法相比,灵敏度及总灵敏度均达100%,检测Sp、Hib特异性分别为94%、98%,总特异性达92%。结论:所建立的多重降落PCR具有高灵敏度与特异性,可作为Sp、Hib感染的快速诊断与流行病学研究的备选手段。     

佛山地区呼吸机相关性肺炎病原学与细菌耐药性变迁的研究

目的：探讨佛山地区呼吸机相关性肺炎（VAP）病原学与细菌耐药性变迁状况。方法：将我市3家医院的120例VAP进行痰细菌培养及药敏试验,总结分析病原学与细菌耐药性变迁。结果：铜绿假单胞菌检出率在两年度均占首位,分别为21.33%及26.15%,并对头孢噻肟100%耐药,对亚胺培南也产生了严重耐药,耐药率由原来的0增至47.06%,对头孢哌酮/舒巴坦和头孢他啶的耐药率分别由原来的12.50%和25.00%增至52.49%和41.17%,对阿米卡星、左旋氧氟沙星和哌拉西林/他唑巴坦等药物的耐药率也不同程的增加;鲍曼不动杆菌和嗜麦芽假单胞菌两年度检出率分别为17.33%、16.92%和8.00%、12.34%,在两年内对多种抗生素的耐药性均有不同程度的增加;肺炎克雷伯菌和洋葱假单胞菌的检出率两年来出现下降趋势,真菌在两年度中仍具有较高的检出率,未发现耐药菌株。结论：各个细菌对抗生素的耐药谱不断发生变化,临床医师应及时掌握病原学及耐药性的变迁,并合理选择抗生素。     

脑脊液乳酸脱氢酶检测在脑膜炎诊断中的临床意义

目的探讨脑脊液乳酸脱氢酶（LDH）检测在鉴别细菌性脑膜炎和病毒性脑膜炎的临床应用价值。方法采用速率法检测48例细菌性脑膜炎、45例病毒性脑膜炎以及对照组40例脑脊液LDH和血清LDH的浓度。结果细菌性脑膜炎患者LDH浓度明显高于病毒性脑膜炎患者以及正常对照组（P〈0．05）;而病毒性脑膜炎患者脑脊液LDH浓度与对照组相比差异无统计学意义（P〉0．05）。细菌性脑膜炎血清LDH与病毒性脑膜炎比较差异无统计学意义（P〉0．05）。结论脑脊液LDH检测可作为细菌性脑膜炎和病毒性脑膜炎的鉴别诊断,对于临床药物的选择具有重要的指导意义。     

Invasive Haemophilus influenzae type b infections in children in Paraguay

BACKGROUND: In Paraguay, as in most Latin American countries, data on the epidemiology and clinical characteristics of Haemophilus influenzae type b (Hib) diseases are scarce and incomplete. METHODS: To address this issue, we performed a retrospective analysis of 102 patients admitted to the Instituto de Medicina Tropical, a referral hospital in Asunción, Paraguay, between January 1991 and September 1995 with diagnosis of invasive Hib infection. This study included patients 15 years of age and under-identified with positive cultures for Hib in blood, cerebrospinal fluid, or other sterile body fluids. RESULTS: Eighty three (81%) patients presented with meningitis as principal focus of infection with median age of 9 months. Forty five (54%) patients with Hib meningitis were <12 months of age and 20 (24% of total cases) were <6 months of age. Overall mortality rate of meningitis was 13%. Of 11 patients who died, 10 (91%) were <12 months of age (p <0.02). Risk for mortality was correlated with presence of coma during admission (p <0.007) and CSF glucose level of <10 mg/dL (p <0.05). Severe sequelae such as bilateral hearing loss, hydrocephalus, and mental retardation were observed in 39% (28/72) of surviving patients, of whom 18 (51%) patients were <12 months of age (p <0.02). Thirty percent of isolated strains of Hib were resistant to ampicillin, 20% were resistant to chloramphenicol, and 10% to both drugs. CONCLUSIONS: This information provides evidence concerning the importance of continued support for Hib vaccine supplies in immunization programs in countries with limited resources such as Paraguay.     

Recent trends in pediatric Haemophilus influenzae type B infections in Canada. Immunization Monitoring Program, Active (IMPACT) of the Canadian Paediatric Society and the Laboratory Centre for Disease Control.

OBJECTIVE: To describe changes in the number of cases of Haemophilus influenzae type b (Hib) infections among Canadian children before and after the introductory phases of Hib vaccination. DESIGN: Multicentre case series. SETTING: All 10 pediatric tertiary care centres across Canada participating in the Immunization Monitoring Program, Active (IMPACT) of the Canadian Paediatric Society and the Laboratory Centre for Disease control. PATIENTS: Children with a Hib infection admitted to any of the participating hospitals from 1985 to 1994. Annual case totals from 1985 to 1990 were determined from records of hospital laboratories or coded discharge diagnoses, or both. From 1991 to 1994 intensive case surveillance was conducted on the wards in addition to thorough record searches as above. OUTCOME MEASURES: Estimated annual case totals for 1985-90. For 1991-94 intensive surveillance for quarterly case totals, yearly age distribution of cases, and proportion of recent cases that represent vaccination failures or missed opportunities to prevent infection. RESULTS: The total number of Hib cases from 1985 to 1990 was 2095; from 1991 to 1994, there were 326 laboratory-confirmed cases and 15 probably cases supported by Hib antigen detection. The annual number of cases declined from an estimated 485 in 1985 to 24 in 1994, a decrease of 95.1%. The steepest interannual decrease (63.7%) occurred between 1992 and 1993, following the introduction of infant-based vaccination programs across Canada. The number of Hib cases involving children most at risk (those 6 to 18 months old) decreased from 78 in 1991 to 4 in 1994. Of the 24 cases in 1994, 6 were categorized as preventable, 1 was fatal, and 8 were vaccine failures (2 of which involved currently used vaccines). CONCLUSION: The prevalence of Hib infections reported by the IMPACT centres has declined greatly since the introduction of vaccination programs. However, deaths and complications continue to occur, attesting to the need to vaccinate all eligible infants and children against this virulent pathogen.     

2013-2018年北京市顺义区哨点医院腹泻病例中致泻性大肠埃希菌流行特征分析

目的 了解北京市顺义区腹泻病例中致泻性大肠埃希菌(diarrheagenic Escherichia coli,DEC)的流行特征,为顺义区DEC引起的腹泻防控工作提供科学依据。方法 收集2013至2018年北京市顺义区2家哨点医院肠道门诊腹泻患者临床和流行病学资料,采集粪便标本进行DEC检测,数据采用SPSS 25.0和Excel 2010进行流行病学分析。 结果 2 068例腹泻监测病例中检出DEC 182例(8.80%),检出率由高到低依次为肠产毒性大肠埃希菌(enterotoxigenic E.coli, ETEC)(111例,5.37%)、肠致病性大肠埃希菌(enteropathogenic E.coli,EPEC)(45例,2.18%)、肠集聚性大肠埃希菌(enteroaggregative E.coli, EAEC)(27例,1.31%)(各类型DEC检出数相加大于阳性例数是由于混合感染者分别计算到各类型引起),且不同户籍、不同性别、不同年龄的检出率差异无统计学意义。DEC的季节性发病特征明显,各菌型的流行高峰均在夏季,主要表现为ETEC(χ²=76.591,P<0.001)和EAEC(χ²=10.204,P<0.05);本市患者EPEC(χ²=12.243,P<0.001)和EAEC(χ²=7.947,P<0.01)阳性检出率高;不同年龄EAEC检出率差异有统计学意义(χ²=17.171,P<0.05)。发热、恶心、腹痛、脱水症状对DEC检出率无影响,但无呕吐症状病例DEC检出率高(χ²=7.099,P<0.01),主要体现为ETEC(χ²=15.073,P<0.001);伴发热与无发热组EAEC检出率差异有统计学意义(χ²=4.951,P<0.05)。结论 北京市顺义区DEC流行的优势菌型主要为ETEC、EPEC和EAEC,季节性发病特征明显,夏季应加强DEC引起腹泻的防控工作。     

Haemophilus influenzae type b meningitis: how much better is prevention than cure?

Haemophilus influenzae type b (Hib) is a major cause of meningitis and pneumonia in children. In Papua New Guinea (PNG) more than 20% of Hib are now resistant to chloramphenicol, and resistant Hib meningitis treated with chloramphenicol results in certain death or severe brain injury. Third-generation cephalosporins are a therapeutic option but are very expensive, while the Haemophilus influenzae type b conjugate vaccine would provide effective prevention. In a province of 380,000 people, using ceftriaxone as standard treatment for meningitis in all health facilities would only save an estimated 8 more lives per year than using chloramphenicol, and cost US dollars 1514 per additional life saved. Introduction of Hib vaccine would save, each year, 61 more lives than using chloramphenicol and 53 more lives than using ceftriaxone for meningitis treatment. The cost of a vaccination strategy for Hib meningitis would be US dollars 1216 for each of the 61 additional lives saved. Hib vaccine would be by far the most effective intervention to reduce mortality and severe neurological disability from Hib meningitis in PNG. Nationwide introduction of Hib vaccine is urgently needed, as antibiotics are now less effective in this disease than ever before.