RESUMEN
In 2012 the World Health Organization (WHO) aimed to eliminate measles in five regions by 2020. This retrospective descriptive study reviewed measles surveillance data in South Africa for the period 2015-2020 to document the epidemiology of measles and the progress made towards meeting the 2020 measles elimination goal.A total of 22,578 specimens were tested over the period 2015-2020 yielding 401 (1.8%) confirmed measles cases, 321 (1.4%) compatible and 21,856 (96.8%) discarded cases. The most affected age group was 0-4 year olds. At the provincial level, South Africa achieved adequate surveillance, defined as more than two cases of febrile rash notified annually per 100 000 popoulation, except for KwaZulu-Natal and Limpopo in 2020, probably due to COVID-19 lockdown restrictions. Of confirmed cases, only 26% were vaccinated, 3% were too young to receive vaccines, 5% were not vaccinated, and 65% had unknown vaccination status. Measles vaccine effectiveness amongst 1-4 year olds was 80%. Using the standard case definition, South Africa achieved the measles elimination target of less than one case per one million nationally in years 2015, 2016 and 2020. The years 2017 to 2019 had incidence rates exceeding one per million nationally. Using a narrow case definition, that excluded positive rubella cases, improved the indicators with only the year 2017 having an incidence rate of more than one per million.South Africa displays intermittent measles outbreaks approximately six-yearly interspersed by inter-epidemic periods in which the country meets measles elimination targets. Intense effort is needed to increase the vaccine coverage to avoid periodic outbreaks. Enhanced molecular testing of each case will be required as measles incidence declines regionally.
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COVID-19 , Sarampión , Preescolar , Control de Enfermedades Transmisibles , Erradicación de la Enfermedad , Brotes de Enfermedades , Humanos , Programas de Inmunización , Incidencia , Lactante , Sarampión/epidemiología , Sarampión/prevención & control , Vacuna Antisarampión/uso terapéutico , Estudios Retrospectivos , Sudáfrica/epidemiología , VacunaciónRESUMEN
BACKGROUND: Congenital rubella syndrome (CRS) includes disorders associated with intrauterine rubella infection. Incidence of CRS is higher in countries with no rubella-containing vaccines (RCV) in their immunization schedules. In the World Health Organization African region, RCVs are being introduced as part of the 2012-2020 global measles and rubella strategic plan. This study aimed to describe the epidemiology of confirmed CRS in South Africa prior to introduction of RCVs in the immunization schedule. METHODS: This was a descriptive study with 28 sentinel sites reporting laboratory-confirmed CRS cases in all 9 provinces of South Africa. In the retrospective phase (2010 to 2014), CRS cases were retrieved from medical records, and in the prospective phase (2015 to 2017) clinicians at study sites reported CRS cases monthly. RESULTS: There were 42 confirmed CRS cases in the retrospective phase and 53 confirmed CRS cases in the prospective phase. Most frequently reported birth defects were congenital heart disease and cataracts. The median age of mothers of CRS cases was 21 years in the retrospective phase (range: 11 to 38 years) and 22 years in the prospective phase (range: 15 to 38 years). CONCLUSION: Baseline data on laboratory-confirmed CRS will enable planning and monitoring of RCV implementation in the South African Expanded Programme on Immunization program. Ninety-eight percent of mothers of infants with CRS were young women 14-30 years old, indicating a potential immunity gap in this age group for consideration during introduction of RCV.
Asunto(s)
Anticuerpos Antivirales/sangre , Complicaciones Infecciosas del Embarazo/prevención & control , Síndrome de Rubéola Congénita/epidemiología , Síndrome de Rubéola Congénita/prevención & control , Vigilancia de Guardia , Adolescente , Adulto , Estudios Transversales , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Registros Médicos , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/virología , Estudios Prospectivos , Investigación Cualitativa , Estudios Retrospectivos , Virus de la Rubéola , Sudáfrica , Adulto JovenRESUMEN
BACKGROUND: Measles continues to circulate in the Democratic Republic of Congo, and the country suffered from several important outbreaks over the last 5 years. Despite a large outbreak starting in the former province of Katanga in 2010 and the resulting immunization activities, another outbreak occurred in 2015 in this same region. We conducted measles seroprevalence surveys in four health zones (HZ) in the former Katanga Province in order to assess the immunity against measles in children 6 months to 14 years after the 2015 outbreak. METHODS: We conducted multi-stage cluster surveys stratified by age group in four HZs, Kayamba, Malemba-Nkulu, Fungurume, and Manono. The age groups were 6-11 months, 12-59 months, and 5-14 years in Kayamba and Malemba-Nkulu, 6-59 months and 5-14 years in Manono and Fungurume. The serological status was measured on dried capillary blood spots collected systematically along with vaccination status (including routine Extended Program of Immunization (EPI), and supplementary immunization activities (SIAs)) and previous self-reported history of suspected measles. RESULTS: Overall seroprevalence against measles was 82.7% in Kayamba, 97.6% in Malemba-Nkulu, 83.2% in Manono, and 74.4% in Fungurume, and it increased with age in all HZs. It was 70.7 and 93.8% in children 12-59 months in Kayamba and Malemba-Nkulu, and 49.8 and 64.7% in children 6-59 months in Fungurume and Manono. The EPI coverage was low but varied across HZ. The accumulation of any type of vaccination against measles resulted in an overall vaccine coverage (VC) of at least 85% in children 12-59 months in Kayamba and Malemba-Nkulu, 86.1 and 74.8% in children 6-59 months in Fungurume and Manono. Previous measles infection in 2015-early 2016 was more frequently reported in children aged 12-59 months or 6-59 months (depending on the HZ). CONCLUSION: The measured seroprevalence was consistent with the events that occurred in these HZs over the past few years. Measles seroprevalence might prove a valuable source of information to help adjust the timing of future SIAs and prioritizing support to the EPI in this region as long as the VC does not reach a level high enough to efficiently prevent epidemic flare-ups.
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Brotes de Enfermedades/prevención & control , Programas de Inmunización , Vacuna Antisarampión/administración & dosificación , Sarampión/epidemiología , Adolescente , Niño , Preescolar , República Democrática del Congo/epidemiología , Femenino , Humanos , Lactante , Masculino , Sarampión/prevención & control , Estudios SeroepidemiológicosRESUMEN
A critical component of laboratory surveillance for measles is the genetic characterization of circulating wild-type viruses. The World Health Organization (WHO) Measles and Rubella Laboratory Network (LabNet), provides for standardized testing in 183 countries and supports genetic characterization of currently circulating strains of measles viruses. The goal of this report is to describe the lessons learned from nearly 20 years of virologic surveillance for measles, to describe the global databases for measles sequences, and to provide regional updates about measles genotypes detected by recent surveillance activities. Virologic surveillance for measles is now well established in all of the WHO regions, and most countries have conducted at least some baseline surveillance. The WHO Global Genotype Database contains >7000 genotype reports, and the Measles Nucleotide Surveillance (MeaNS) contains >4000 entries. This sequence information has proven to be extremely useful for tracking global transmission patterns and for documenting the interruption of transmission in some countries. The future challenges will be to develop quality control programs for molecular methods and to continue to expand virologic surveillance activities in all regions.
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Salud Global , Virus del Sarampión/clasificación , Virus del Sarampión/genética , Sarampión/epidemiología , Sarampión/virología , Bases de Datos Factuales , Genotipo , Humanos , Epidemiología Molecular , Organización Mundial de la SaludRESUMEN
The suspected measles case definition captures rubella cases. Therefore, measles surveillance will be improved in the course of the control and eventual elimination of rubella transmission. One aspect of rubella control, virologic surveillance, is reviewed here. A systematic nomenclature for rubella viruses (RVs) based on 13 genotypes has been established and is updated when warranted by increases in information about RVs. From 2005 through 2010, the genotypes of RVs most frequently reported were 1E, 1G, and 2B, and genotypes 1a, 1B, 1C, 1h, 1j, and 2C were less frequently reported. Virologic surveillance can support rubella control and elimination. Synopses of rubella virologic surveillance in various countries, regions, and globally are given, including characterization of viruses from imported cases in a country that has eliminated rubella and studies of endemic viruses circulating in countries without rubella control objectives. Current challenges are discussed.
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Salud Global , Vacuna contra el Sarampión-Parotiditis-Rubéola , Virus de la Rubéola/genética , Rubéola (Sarampión Alemán)/epidemiología , Rubéola (Sarampión Alemán)/virología , Genotipo , Humanos , Sarampión/epidemiología , Sarampión/prevención & control , Vacuna Antisarampión/administración & dosificación , Vacuna contra el Sarampión-Parotiditis-Rubéola/administración & dosificación , Filogenia , Vigilancia de la Población , Rubéola (Sarampión Alemán)/prevención & control , Virus de la Rubéola/clasificación , Organización Mundial de la Salud/organización & administraciónRESUMEN
South Africa has yet to introduce a rubella-containing vaccine (RCV) into its Expanded Programme on Immunisation (EPI). Here we evaluated the incidence of laboratory-confirmed rubella and congenital rubella syndrome (CRS) cases over the years 2015 to 2019, to document the epidemiology of rubella and CRS within South Africa prior to a RCV introduction. This retrospective study evaluated the number of laboratory-confirmed rubella cases reported through the national febrile rash surveillance system. A positive test for rubella immunoglobulin M (IgM) antibodies was considered a confirmed rubella case. For CRS cases, we reported laboratory-confirmed CRS cases collected from 28 sentinel-sites from all nine provinces of South Africa. From 2015-2019, 19 773 serum samples were tested for rubella IgM antibodies, 6 643 (33.6%) were confirmed rubella cases. Rubella was seasonal, with peaks in spring (September to November). Case numbers were similar between males (n = 3 239; 50.1%) and females (n = 3 232; 49.9%). The highest burden of cases occurred in 2017 (n = 2 526; 38%). The median age was 5 years (IQR: 3-7 years). Importantly, of females with rubella, 5.0% (161 of 3 232) of the cases were among women of reproductive age (15-44 years). A total of 62 CRS cases were reported, the mortality rate was 12.9% (n = 8), and the most common birth defect was congenital heart disease. In conclusion, rubella is endemic in South Africa. Children below the age of 10 years were the most affected, however, rubella was also reported among women of reproductive age. The baseline data represented here provides insight into the burden of rubella and CRS in South Africa prior to the introduction of a RCV, and can enable planning of RCV introduction into the South African EPI.
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Síndrome de Rubéola Congénita , Rubéola (Sarampión Alemán) , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Inmunoglobulina M , Incidencia , Lactante , Masculino , Estudios Retrospectivos , Rubéola (Sarampión Alemán)/epidemiología , Rubéola (Sarampión Alemán)/prevención & control , Síndrome de Rubéola Congénita/epidemiología , Síndrome de Rubéola Congénita/prevención & control , Vacuna contra la Rubéola , Virus de la Rubéola , Sudáfrica/epidemiología , Adulto JovenRESUMEN
To determine what measles virus genotype(s) circulated in Uganda after strategic interventions aimed at controlling/eliminating measles, we examined samples obtained during 2006-2009 and found only genotype B3.1, which had not been previously detected. Kenya was the likely source, but other countries cannot be excluded.
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Vacuna Antisarampión/administración & dosificación , Virus del Sarampión/genética , Virus del Sarampión/aislamiento & purificación , Sarampión/prevención & control , Sarampión/transmisión , Vacunación/estadística & datos numéricos , Adolescente , Niño , Preescolar , Genotipo , Humanos , Lactante , Sarampión/virología , Virus del Sarampión/clasificación , Faringe/virología , Vigilancia de la Población/métodos , Uganda/epidemiología , Orina/virologíaRESUMEN
We investigated the genetic diversity of measles virus (MV) in Nigeria (2004-2005) and the Democratic Republic of the Congo (DRC) (2002-2006). Genotype B3 strains circulating in Kinshasa, DRC, in 2002-2003 were fully replaced by genotype B2 in 2004 at the end of the second Congo war. In Nigeria (2004-2005), two genetic clusters of genotype B3, both of which were most closely related to 1 variant from 1998, were identified. Longitudinal analysis of MV strain diversity in Nigeria suggested that only a few of the previously described 1997-1998 variants had continued to circulate, but this finding was concomitant with a rapid restoration of genetic diversity, probably caused by low vaccination coverage and high birth rates. In contrast, the relatively low genetic diversity of MV in DRC and the genotype replacement in Kinshasa reflect a notable improvement in local measles control.
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Variación Genética , Virus del Sarampión/genética , Sarampión/epidemiología , Sarampión/virología , República Democrática del Congo/epidemiología , Humanos , Niger/epidemiología , Filogenia , Factores de TiempoRESUMEN
BACKGROUND: An outbreak of Marburg hemorrhagic fever was first observed in a gold-mining village in northeastern Democratic Republic of the Congo in October 1998. METHODS: We investigated the outbreak of Marburg hemorrhagic fever most intensively in May and October 1999. Sporadic cases and short chains of human-to-human transmission continued to occur until September 2000. Suspected cases were identified on the basis of a case definition; cases were confirmed by the detection of virus antigen and nucleic acid in blood, cell culture, antibody responses, and immunohistochemical analysis. RESULTS: A total of 154 cases (48 laboratory-confirmed and 106 suspected) were identified (case fatality rate, 83 percent); 52 percent of cases were in young male miners. Only 27 percent of these men reported having had contact with other affected persons, whereas 67 percent of patients who were not miners reported such contact (P<0.001). Most of the affected miners (94 percent) worked in an underground mine. Cessation of the outbreak coincided with flooding of the mine. Epidemiologic evidence of multiple introductions of infection into the population was substantiated by the detection of at least nine genetically distinct lineages of virus in circulation during the outbreak. CONCLUSIONS: Marburg hemorrhagic fever can have a very high case fatality rate. Since multiple genetic variants of virus were identified, ongoing introduction of virus into the population helped perpetuate this outbreak. The findings imply that reservoir hosts of Marburg virus inhabit caves, mines, or similar habitats.
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Brotes de Enfermedades , Enfermedad del Virus de Marburg/epidemiología , Marburgvirus/genética , Adolescente , Adulto , Anciano , Animales , Niño , Preescolar , República Democrática del Congo/epidemiología , Reservorios de Enfermedades , Femenino , Oro , Humanos , Lactante , Recién Nacido , Masculino , Enfermedad del Virus de Marburg/mortalidad , Enfermedad del Virus de Marburg/transmisión , Enfermedad del Virus de Marburg/virología , Marburgvirus/aislamiento & purificación , Persona de Mediana Edad , Minería , Estaciones del Año , Análisis de Secuencia de ADNRESUMEN
INTRODUCTION AND METHODS: Hepatitis B is a vaccine preventable disease and is notifiable in South Africa. Hepatitis B vaccination was incorporated into the Expanded Programme on Immunisation in South Africa in 1995. We used a convenience sample from community-based febrile rash surveillance in 2013 to estimate hepatitis B sero-prevalence. Of samples serologically negative for acute measles infection, 450 samples spanning nine provinces of South Africa were tested for hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody (anti-HBc). RESULTS: Two children (2/450; 0.4%) tested positive for HBsAg. Three hundred and three children (67.3%) had evidence of vaccine induced immunity. Vaccine induced immunity was present in 80.2% of 1-5 year olds, but only 60.3% of 10-14 year olds. Natural immunity, indicating exposure to circulating hepatitis B, was present in 13/450 (2.9%) children. CONCLUSION: Chronic hepatitis B in South African has decreased in prevalence from highly endemic levels prior to vaccine introduction to approximately 0.4% in this sample, demonstrating impact of a successful vaccination programme 18 years after introduction. Decreased vaccine-induced immunity with increasing age may reflect waning antibody titres over time.
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Exantema/virología , Vacunas contra Hepatitis B/inmunología , Hepatitis B/epidemiología , Hepatitis B/inmunología , Adolescente , Niño , Preescolar , Femenino , Anticuerpos contra la Hepatitis B/inmunología , Antígenos del Núcleo de la Hepatitis B/inmunología , Antígenos de Superficie de la Hepatitis B/inmunología , Humanos , Programas de Inmunización/métodos , Lactante , Recién Nacido , Masculino , Sarampión/virología , Prevalencia , Sudáfrica/epidemiología , Vacunación/métodosRESUMEN
BACKGROUND: Rubella virus (RV) causes a mild disease, but maternal infection early in pregnancy often leads to birth defects known as congenital rubella syndrome (CRS). Rubella remains poorly controlled in Africa. OBJECTIVES: To identify RV genotypes found in Africa to help establish a genetic baseline for RV molecular epidemiology. STUDY DESIGN: Urine and nasopharyngeal specimens were collected between 2001 and 2004 during measles surveillance in Morocco, Uganda and South Africa, and from two persons in the United States who contracted rubella in Cote d'Ivoire and Uganda in 2004 and 2007, respectively. RV RNA was obtained directly from specimens or from RV-infected cell cultures, amplified by reverse transcriptase polymerase chain reaction, and the resulting DNAs sequenced. Sequences were assigned to genotypes by phylogenetic analysis with RV reference sequences. RESULTS: Nine RV sequences were assigned as follows: 1E in Morocco, 1G in Uganda and Cote d'Ivoire, and 2B in South Africa. CONCLUSIONS: Information about RV genotypes circulating in Africa is improved which should aid in control of rubella and CRS in Africa.
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ARN Viral/genética , Virus de la Rubéola/clasificación , Virus de la Rubéola/aislamiento & purificación , Rubéola (Sarampión Alemán)/virología , Adulto , Niño , Preescolar , Côte d'Ivoire , Femenino , Genotipo , Humanos , Recién Nacido , Persona de Mediana Edad , Datos de Secuencia Molecular , Marruecos , Nasofaringe/virología , Filogenia , Embarazo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Virus de la Rubéola/genética , Análisis de Secuencia de ADN , Sudáfrica , Uganda , Estados Unidos , Orina/virologíaRESUMEN
BACKGROUND: One of the countries where measles remains endemic is Ethiopia. Previously, sequence data from Measles Viruses (MV) circulating in Ethiopia were obtained from clinical specimens. Now the Ethiopian Health and Nutrition Research Institute (ENHRI) has implemented cell culture techniques to isolate measles virus and molecular epidemiologic studies can be generated more easily. OBJECTIVE: To characterize the strains of Measles Virus circulating in Ethiopia during measles outbreaks in 2006 using viral isolates, and compare the results to previously identified Ethiopian strains. METHODS: A case study and convenience sampling method were conducted on five measles outbreak cases tb identify the circulating measles virus genotype in Addis Ababa and Amhara regions of Ethiopia in 2006. RESULTS: Three isolates were obtained from five specimens collected in two regions (1 from Amhara: Bahir Dar, and 2 from Addis Ababa: Addis Ketema and Kolefe Keranio subcities) in Ethiopia during 2006. The viral isolates were analyzed using standard genotyping protocols and were classified as genotype B3, identical to the strain circulating widely in West Africa and imported into Europe (Britain, Netherlands, Germany) and America (Mexico, USA, Canada). CONCLUSION: The conserved sequences among three isolates, covering a 3-month period, suggest that this B3 strain was circulating in Addis Ababa, Bahir Dar and possibly elsewhere in Ethiopia. To interrupt the transmission and circulation of MV, Ethiopia needs a strong national program of epidemiological surveillance, with characterization of circulating MV performed in a timely manner.
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Brotes de Enfermedades , Virus del Sarampión/aislamiento & purificación , Sarampión/epidemiología , Sarampión/virología , Adolescente , Adulto , Preescolar , Etiopía/epidemiología , Femenino , Genotipo , Humanos , Masculino , Sarampión/transmisión , Virus del Sarampión/genéticaRESUMEN
BACKGROUND: The World Health Organization, African Region, set the goal of achieving measles elimination by 2020. Namibia was one of seven African countries to implement an accelerated measles control strategy beginning in 1996. Following implementation of this strategy, measles incidence decreased; however, between 2009 and 2011 a major outbreak occurred in Namibia. METHODS: Measles vaccination coverage data were analysed and a descriptive epidemiological analysis of the measles outbreak was conducted using measles case-based surveillance and laboratory data. RESULTS: During 1989 - 2008, MCV1 (the first routine dose of measles vaccine) coverage increased from 56% to 73% and five supplementary immunisation activities were implemented. During the outbreak (August 2009 - February 2011), 4 605 suspected measles cases were reported; of these, 3 256 were confirmed by laboratory testing or epidemiological linkage. Opuwo, a largely rural district in north-western Namibia with nomadic populations, had the highest confirmed measles incidence (16 427 cases per million). Infants aged ≤11 months had the highest cumulative age-specific incidence (9 252 cases per million) and comprised 22% of all confirmed cases; however, cases occurred across a wide age range, including adults aged ≥30 years. Among confirmed cases, 85% were unvaccinated or had unknown vaccination history. The predominantly detected measles virus genotype was B3, circulating in concurrent outbreaks in southern Africa, and B2, previously detected in Angola. CONCLUSION: A large-scale measles outbreak with sustained transmission over 18 months occurred in Namibia, probably caused by importation. The wide age distribution of cases indicated measles-susceptible individuals accumulated over several decades prior to the start of the outbreak.
RESUMEN
INTRODUCTION: Despite accelerated measles control efforts, a massive measles resurgence occurred in the Democratic Republic of the Congo (DRC) starting in mid-2010, prompting an investigation into likely causes. METHODS: We conducted a descriptive epidemiological analysis using measles immunization and surveillance data to understand the causes of the measles resurgence and to develop recommendations for elimination efforts in DRC. RESULTS: During 2004-2012, performance indicator targets for case-based surveillance and routine measles vaccination were not met. Estimated coverage with the routine first dose of measles-containing vaccine (MCV1) increased from 57% to 73%. Phased supplementary immunization activities (SIAs) were conducted starting in 2002, in some cases with sub-optimal coverage (≤95%). In 2010, SIAs in five of 11 provinces were not implemented as planned, resulting in a prolonged interval between SIAs, and a missed birth cohort in one province. During July 1, 2010-December 30, 2012, high measles attack rates (>100 cases per 100,000 population) occurred in provinces that had estimated MCV1 coverage lower than the national estimate and did not implement planned 2010 SIAs. The majority of confirmed case-patients were aged <10 years (87%) and unvaccinated or with unknown vaccination status (75%). Surveillance detected two genotype B3 and one genotype B2 measles virus strains that were previously identified in the region. CONCLUSION: The resurgence was likely caused by an accumulation of unvaccinated, measles-susceptible children due to low MCV1 coverage and suboptimal SIA implementation. To achieve the regional goal of measles elimination by 2020, efforts are needed in DRC to improve case-based surveillance and increase two-dose measles vaccination coverage through routine services and SIAs.
Asunto(s)
Brotes de Enfermedades , Vacuna Antisarampión/administración & dosificación , Virus del Sarampión/aislamiento & purificación , Sarampión/epidemiología , Adolescente , Niño , Preescolar , República Democrática del Congo/epidemiología , Genotipo , Humanos , Inmunización/estadística & datos numéricos , Lactante , Sarampión/prevención & control , Sarampión/virología , Virus del Sarampión/genética , Vigilancia de la PoblaciónRESUMEN
INTRODUCTION: In seven southern African countries (Botswana, Lesotho, Malawi, Namibia, South Africa, Swaziland and Zimbabwe), following implementation of a measles mortality reduction strategy starting in 1996, the number of annually reported measles cases decreased sharply to less than one per million population during 2006-2008. However, during 2009-2010, large outbreaks occurred in these countries. In 2011, a goal for measles elimination by 2020 was set in the World Health Organization (WHO) African Region (AFR). We reviewed the implementation of the measles control strategy and measles epidemiology during the resurgence in the seven southern African countries. METHODS: Estimated coverage with routine measles vaccination, supplemental immunization activities (SIA), annually reported measles cases by country, and measles surveillance and laboratory data were analyzed using descriptive analysis. RESULTS: In the seven countries, coverage with the routine first dose of measles-containing vaccine (MCV1) decreased from 80% to 65% during 1996-2004, then increased to 84% in 2011; during 1996-2011, 79,696,523 people were reached with measles vaccination during 45 SIAs. Annually reported measles cases decreased from 61,160 cases to 60 cases and measles incidence decreased to <1 case per million during 1996-2008. During 2009-2010, large outbreaks that included cases among older children and adults were reported in all seven countries, starting in South Africa and Namibia in mid-2009 and in the other five countries by early 2010. The measles virus genotype detected was predominantly genotype B3. CONCLUSION: The measles resurgence highlighted challenges to achieving measles elimination in AFR by 2020. To achieve this goal, high two-dose measles vaccine coverage by strengthening routine immunization systems and conducting timely SIAs targeting expanded age groups, potentially including young adults, and maintaining outbreak preparedness to rapidly respond to outbreaks will be needed.
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Vacuna Antisarampión/uso terapéutico , Sarampión/epidemiología , Vigilancia de la Población , Vacunación/estadística & datos numéricos , Adolescente , Adulto , África Austral/epidemiología , Niño , Preescolar , Erradicación de la Enfermedad , Brotes de Enfermedades/prevención & control , Femenino , Humanos , Programas de Inmunización , Incidencia , Lactante , Masculino , Adulto JovenRESUMEN
BACKGROUND: Since 1995, measles vaccination at nine and 18 months has been routine in South Africa; however, coverage seldom reached >95%. We describe the epidemiology of laboratory-confirmed measles case-patients and assess the impact of the nationwide mass vaccination campaign during the 2009 to 2011 measles outbreak in South Africa. METHODS: Serum specimens collected from patients with suspected-measles were tested for measles-specific IgM antibodies using an enzyme-linked immunosorbent assay and genotypes of a subset were determined. To estimate the impact of the nationwide mass vaccination campaign, we compared incidence in the seven months pre- (1 September 2009-11 April 2010) and seven months post-vaccination campaign (24 May 2010-31 December 2010) periods in seven provinces of South Africa. RESULTS: A total of 18,431 laboratory-confirmed measles case-patients were reported from all nine provinces of South Africa (cumulative incidence 37 per 100,000 population). The highest cumulative incidence per 100,000 population was in children aged <1 year (603), distributed as follows: <6 months (302/100,000), 6 to 8 months (1083/100,000) and 9 to 11 months (724/100,000). Forty eight percent of case-patients were ≥ 5 years (cumulative incidence 54/100,000). Cumulative incidence decreased with increasing age to 2/100,000 in persons ≥ 40 years. A single strain of measles virus (genotype B3) circulated throughout the outbreak. Prior to the vaccination campaign, cumulative incidence in the targeted vs. non-targeted age group was 5.9-fold higher, decreasing to 1.7 fold following the campaign (P<0.001) and an estimated 1,380 laboratory-confirmed measles case-patients were prevented. CONCLUSION: We observed a reduction in measles incidence following the nationwide mass vaccination campaign even though it was conducted approximately one year after the outbreak started. A booster dose at school entry may be of value given the high incidence in persons >5 years.
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Técnicas de Laboratorio Clínico , Brotes de Enfermedades/prevención & control , Sarampión/epidemiología , Sarampión/prevención & control , Adolescente , Adulto , Distribución por Edad , Niño , Preescolar , Femenino , Genotipo , Humanos , Inmunoglobulina M/inmunología , Incidencia , Lactante , Masculino , Sarampión/genética , Sarampión/inmunología , Vacuna Antisarampión/administración & dosificación , Vacuna Antisarampión/inmunología , Reproducibilidad de los Resultados , Sudáfrica/epidemiología , VacunaciónRESUMEN
To determine reservoir hosts for Marburg virus (MARV), we examined the fauna of a mine in northeastern Democratic Republic of the Congo. The mine was associated with a protracted outbreak of Marburg hemorrhagic fever during 1998-2000. We found MARV nucleic acid in 12 bats, comprising 3.0%-3.6% of 2 species of insectivorous bat and 1 species of fruit bat. We found antibody to the virus in the serum of 9.7% of 1 of the insectivorous species and in 20.5% of the fruit bat species, but attempts to isolate virus were unsuccessful.
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Quirópteros/virología , Marburgvirus/inmunología , Marburgvirus/aislamiento & purificación , Animales , Anticuerpos Antivirales/análisis , Anticuerpos Antivirales/inmunología , Quirópteros/clasificación , Quirópteros/inmunología , República Democrática del Congo , Marburgvirus/genética , Minería , Filogenia , ARN Viral/genética , ARN Viral/aislamiento & purificaciónRESUMEN
An oligonucleotide microarray hybridization method for identification of most known measles virus (MV) genotypes was developed. Like the conventional genotyping method, the microarray relied on detecting sequence differences in the 450-nucleotide region coding for the COOH-terminal 150 amino acids of the nucleoprotein (N). This region was amplified using PCR primers binding to all known MV genotypes. The microarray included 71 pairs of oligonucleotide probes (oligoprobes) immobilized on glass slides. Each pair consisted of a genotype-specific oligoprobe, which matched the sequence of only one target genotype, and a control oligoprobe, which contained mismatches at the nucleotide positions unique to this genotype. A pattern recognition algorithm based on cluster analysis of the ratios of hybridization signals from specific and control oligoprobes was used to identify the specific MV genotype. Following the initial validation, the method was used for rapid genotyping of two panels of coded samples. The results of this study showed good sensitivity (90.7%), specificity (100%), and genotype agreement (91.8%) for the new method compared to the results of genotyping conducted using phylogenetic analysis of viral sequences of the C terminus of the N gene. In addition, the microarray demonstrated the ability to identify potential new genotypes of MV based on the similarity of their hybridization patterns with those of known MV genotypes.
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Virus del Sarampión/genética , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Genotipo , Virus del Sarampión/aislamiento & purificación , Filogenia , Reproducibilidad de los ResultadosRESUMEN
Surveillance of measles virus detected an epidemiologic link between a refugee from Kenya and a Dutch tourist in New Jersey, USA. Identical genotype B3 sequences from patients with contemporaneous cases in the United States, Canada, and Mexico in November and December 2005 indicate that Kenya was likely to have been the common source of virus.
Asunto(s)
Virus del Sarampión/clasificación , Sarampión/virología , Adolescente , Genotipo , Humanos , Masculino , Factores de TiempoRESUMEN
This study describes two measles outbreaks--one in Cape Town, South Africa in November 2002, and the other in Luanda, Angola in March 2003. The outbreaks were notable because they were caused by closely related genotype B2 viruses. This genotype was first described in an outbreak in Libreville, Gabon in the 1980s and was labeled as inactive by the World Health Organization in 2003 because it had not been detected for over 15 years. As the first three cases in the Cape Town outbreak were Angolan citizens who recently arrived from Angola, it appears likely that the source of the virus was Angola. Molecular analysis of specimens collected during the outbreak in Luanda provided direct evidence for the circulation of genotype B2 measles virus (MV) in Angola. This study clearly demonstrates that there is still active circulation of genotype B2 in Africa, and we propose that its apparent inactivity is merely the result of insufficient virologic/molecular surveillance in the region. These findings highlight the need for expanded molecular surveillance in Africa.