Diversity of picornaviruses in rural Bolivia.

The family Picornaviridae is a large and diverse group of viruses that infect humans and animals. Picornaviruses are among the most common infections of humans and cause a wide spectrum of acute human disease. This study began as an investigation of acute flaccid paralysis (AFP) in a small area of eastern Bolivia, where surveillance had identified a persistently high AFP rate in children. Stools were collected and diagnostic studies ruled out poliovirus. We tested stool specimens from 51 AFP cases and 34 healthy household or community contacts collected during 2002-2003 using real-time and semi-nested reverse transcription polymerase chain reaction assays for enterovirus, parechovirus, cardiovirus, kobuvirus, salivirus and cosavirus. Anecdotal reports suggested a temporal association with neurological disease in domestic pigs, so six porcine stools were also collected and tested with the same set of assays, with the addition of an assay for porcine teschovirus. A total of 126 picornaviruses were detected in 73 of 85 human individuals, consisting of 53 different picornavirus types encompassing five genera (all except Kobuvirus). All six porcine stools contained porcine and/or human picornaviruses. No single virus, or combination of viruses, specifically correlated with AFP; however, the study revealed a surprising complexity of enteric picornaviruses in a single community.

Attitudes and practices of auxiliary nurse midwives and accredited social health activists in Uttar Pradesh and Bihar regarding polio immunization in India.

Although India was removed from the list of polio endemic countries in January 2012, maintaining the focus on polio vaccination is critically important to prevent reintroduction of the virus. In 2009-2010, we conducted a study to assess the attitudes and practices of frontline health workers in India regarding polio immunization in Uttar Pradesh and Bihar. More than 95% of auxiliary nurse midwives (ANMs) and accredited social health activists (ASHAs) agreed that polio supplementary immunization campaigns helped in increasing acceptance of all vaccines. The majority of ANMs (60-70%) and ASHAs (56-71%) believed that polio immunization activities benefitted or greatly benefitted other activities they were carrying out. Less than 5% of ANMs and ASHAs felt they were very likely to face resistance when promoting or administering polio vaccine. This study provides information that may be useful for programs in other countries for polio eradication and in India for measles elimination.

Methods for evaluating the impact of vertical programs on health systems: protocol for a study on the impact of the global polio eradication initiative on strengthening routine immunization and primary health care.

BACKGROUND: The impact of vertical programs on health systems is a much-debated topic, and more evidence on this complex relationship is needed. This article describes a research protocol developed to assess the relationship between the Global Polio Eradication Initiative, routine immunization, and primary health care in multiple settings. METHODS/DESIGN: This protocol was designed as a combination of quantitative and qualitative research methods, making use of comparative ethnographies. The study evaluates the impact of the Global Polio Eradication Initiative on routine immunization and primary health care by: (a) combining quantitative and qualitative work into one coherent study design; (b) using purposively selected qualitative case studies to systematically evaluate the impact of key contextual variables; and (c) making extensive use of the method of participant observation to create comparative ethnographies of the impact of a single vertical program administered in varied contexts. DISCUSSION: The study design has four major benefits: (1) the careful selection of a range of qualitative case studies allowed for systematic comparison; (2) the use of participant observation yielded important insights on how policy is put into practice; (3) results from our quantitative analysis could be explained by results from qualitative work; and (4) this research protocol can inform the creation of actionable recommendations. Here, recommendations for how to overcome potential challenges in carrying out such research are presented. This study illustrates the utility of mixed-methods research designs in which qualitative data are not just used to embellish quantitative results, but are an integral component of the analysis.

Paralytic poliomyelitis associated with Sabin monovalent and bivalent oral polio vaccines in Hungary.

Historical records of patients with vaccine-associated paralytic poliomyelitis (VAPP) in Hungary during 1961-1981 were reviewed to assess the risk of VAPP after oral polio vaccine (OPV) administration. A confirmed VAPP case was defined as a diagnosis of paralytic poliomyelitis and residual paralysis at 60 days in a patient with an epidemiologic link to the vaccine. Archived poliovirus isolates were retested using polymerase chain reaction and sequencing of the viral protein 1 capsid region. This review confirmed 46 of 47 cases previously reported as VAPP. Three cases originally linked to monovalent OPV (mOPV) 3 and one case linked to mOPV1 presented after administration of bivalent OPV 1 + 3 (bOPV). The adjusted VAPP risk per million doses administered was 0.18 for mOPV1 (2 cases/11.13 million doses), 2.96 for mOPV3 (32 cases/10.81 million doses), and 12.82 for bOPV (5 cases/390,000 doses). Absence of protection from immunization with inactivated poliovirus vaccine or exposure to OPV virus from routine immunization and recent injections could explain the higher relative risk of VAPP in Hungarian children. In polio-endemic areas in which mOPV3 and bOPV are needed to achieve eradication, the higher risk of VAPP would be offset by the high risk of paralysis due to wild poliovirus and higher per-dose efficacy of mOPV3 and bOPV compared with trivalent OPV.

Poliomyelitis-related case-fatality ratio in India, 2002-2006.

BACKGROUND: On the basis of studies from developed countries, the case-fatality ratio (CFR) of poliomyelitis generally ranges from 2%-5% among children <5 years of age to 10%-30% among adults. However, little information is available for poliomyelitis-related CFR in developing countries. We conducted a study to determine the CFR in India, 1 of the 4 remaining countries with endemic wild poliovirus (WPV) circulation, during outbreaks of WPV infection during 2002 and 2006 and during the inter-epidemic years of 2003-2005. METHODS: We conducted a descriptive analysis with use of data from the acute flaccid paralysis surveillance system in India. Variables analyzed included age, caregiver-reported vaccination status, date of paralysis onset, laboratory results, final case classification, and survival outcome. Our analysis also accounted for surveillance changes that occurred in 2005, impacting case definitions and final classification. RESULTS: In 2006, 45 deaths occurred among 676 WPV cases in India, yielding a CFR of 6.7%. By comparison, in 2002, there were 66 deaths among 1600 reported WPV cases (CFR, 4.2%) and during 2002-2005, CFR was 1.5%-5.2%. All 45 deaths were among 644 (95%) WPV cases in children aged <5 years (CFR, 7.0%). Among those who died, 33 (73%) were children aged <2 years (CFR, 7.1%). CONCLUSIONS: The CFR among children aged <2 years in India is high compared with previously published CFRs for young children, in part because of improved case finding through enhanced surveillance techniques. Fatal cases emphasize the lethal nature of the disease and the importance of achieving polio eradication in India.

Development and consideration of global policies for managing the future risks of poliovirus outbreaks: insights and lessons learned through modeling.

The success of the Global Polio Eradication Initiative promises to bring large benefits, including sustained improvements in quality of life (i.e., cases of paralytic disease and deaths avoided) and costs saved from cessation of vaccination. Obtaining and maintaining these benefits requires that policymakers manage the transition from the current massive use of oral poliovirus vaccine (OPV) to a world without OPV and free of the risks of potential future reintroductions of live polioviruses. This article describes the analytical journey that began in 2001 with a retrospective case study on polio risk management and led to development of dynamic integrated risk, economic, and decision analysis tools to inform global policies for managing the risks of polio. This analytical journey has provided several key insights and lessons learned that will be useful to future analysts involved in similar complex decision-making processes.

Assessing and monitoring vaccination coverage levels: lessons from the Americas

Según lo establecido por la Organización Panamericana de la Salud (OPS), conseguir una alta cobertura de vacunación es una meta esencial para la Región de las Américas. Es indispensable lograr niveles de cobertura de 95 por ciento o mayores para poder alcanzar los objetivos de la OPS de eliminar el sarampión y la rubéola, controlar las enfermedades prevenibles mediante la vacunación, y hacer perdurar la eliminación de la poliomielitis en territorio americano. Para poder alcanzar esos niveles, es imprescindible que las estadísticas de vacunación sean fiables y que las autoridades sanita- rias midan y monitoreen los niveles de cobertura a lo largo del tiempo. Los métodos elegidos por los directores de los programas de vacunación para calcular la cobertura dependerán de la información que haga falta. En general, los directores del Programa Ampliado de Inmunización (PAI) necesitarán información acerca de la cobertura para poder: 1) determinar la verdadera cobertura en los niveles nacional y local, 2) determinar cuán adecuada es la cobertura en una zona determinada, 3) monitorear las tendencias a lo largo del tiempo, y 4) monitorear las actividades de vacunación mientras se están llevando a cabo. Para lograr lo primero -determinar cuáles son los niveles verdaderos de cobertura-, los administradores tienen dos opciones: a) valerse de los datos acerca de las dosis administradas (es decir, el número de dosis de la vacuna que se ha administrado, dividido por la población que debió recibir una dosis) o b) llevar a cabo una encuesta para determinar la cobertura. Para lograr lo segundo -saber si la cobertura en una zona determinada es adecuada (por ej., mayor de 90 por ciento)-, se puede realizar un muestreo por lotes para garantizar la calidad (MLGC). El MLGC es una metodología de encuesta basada en el uso de muestras pequeñas que permite determinar si la cobertura en una zona determinada es adecuada o no, pero no sirve para estimar el nivel de cobertura. Para el tercer propósito -monitorear las tendencias a lo largo del tiempo-, se pueden usar los datos correspondientes al número de dosis administradas. Para lograr el cuarto propósito -determinar si procede vacunar o llevar a cabo una campaña de vacunación u otra actividad afín-, la "herramienta de monitoreo rápido" creada por la OPS es una magnífica solución. Cada uno de estos métodos posee ventajas y desventajas. Los datos sobre el número de dosis...

Measles eradication in the Americas: progress to date.

The region of the Americas has shown extraordinary progress in its fight to interrupt measles transmission. The Pan American Health Organization's recommended strategy includes the following: a 1-time nationwide campaign targeting 1- to 14-year-old children; routine vaccination among 1-year-olds; and nationwide campaigns conducted every 4 years, targeting all 1- to 4-year-olds. Rapid house-to-house monitoring of vaccination and measles surveillance are other essential components of the strategy. During 2001, only 541 cases were confirmed in the region. In 2002, only Venezuela and Colombia had indigenous transmission. After important vaccination efforts in both countries, the last reported case occurred on 20 September 2002, in Venezuela. Since then, no confirmation exists of indigenous measles circulation anywhere else in the region. Nonetheless, important challenges remain, including insufficient coverage during routine and campaign vaccination and inadequate investigation of some cases.

Isolation and characterization of circulating type 1 vaccine-derived poliovirus from sewage and stream waters in Hispaniola.

Twenty-one cases of acute flaccid paralysis (AFP) were reported on the island of Hispaniola in 2000. Laboratory analysis confirmed the presence of circulating vaccine-derived poliovirus (cVDPV) type 1 in stool samples obtained from patients. As a complement to the active search for cases of AFP, environmental sampling was conducted during November and December 2000, to test for cVDPV in sewage, streams, canals, and public latrines. Fifty-five environmental samples were obtained and analyzed for the presence of polioviruses by use of cell culture followed by neutralization and reverse-transcription polymerase chain reaction. Of the 23 positive samples, 10 tested positive for poliovirus type 1, 7 tested positive for poliovirus type 2, 5 tested positive for poliovirus type 3, and 1 tested positive for both poliovirus type 2 and type 3. By sequence analysis of the complete viral capsid gene 1 (VP1), a 2.1%-3.7% genetic sequence difference between 7 type 1 strains and Sabin type 1 vaccine strain was found. Phylogenetic analysis showed that these viruses are highly related to cVDPV isolated from clinical cases and form distinct subclusters related to geographic region. Our findings demonstrate a useful role for environmental surveillance of neurovirulent polioviruses in the overall polio eradication program.

Interruption of indigenous measles transmission in Bolivia since October 2000.

Measles incidence in Bolivia declined after the introduction of campaign strategies in the 1980s. From 1990 to 1993, the peak incidence of measles (59 cases/100,000 population) was in 1992. In 1994, after the goal of interruption of measles transmission was adopted, a national vaccination campaign targeting children <15 years old was conducted and achieved 96% coverage. During 1995-1997, cases declined, although routine coverage was <90% in most years. During 1998-2000, a nationwide epidemic occurred among 2567 case-patients, most of whom were unvaccinated. A national vaccination campaign, with strong supervision, was conducted during November and December 1999 and targeted areas with low coverage. Only 122 cases were confirmed in 2000, with the last confirmed case occurring in October. Crucial to the control of the outbreak were sufficient resources and political support, intensive local planning, door-to-door vaccination with strict supervision, and rapid house-to-house coverage monitoring that improved accountability at the local level and timely and thorough outbreak investigations.

Measles eradication in the Americas: experience in Haiti.

On 8 March 2000 a case of laboratory-confirmed measles was detected in Haiti. Over the ensuing months, an explosive epidemic occurred that spread to 8 of the 9 departments of Haiti, including the nation's capital, Port au Prince. After peaking in the last half of November 2000, the epidemic began a rapid decline. The date of onset for the last confirmed case was 26 September 2001. During the 18 months of the epidemic, 1149 cases were confirmed. To control the epidemic, various strategies were employed, including vaccination campaigns that used fixed posts and door-to-door activities. Critical factors in the success of these campaigns were thorough training and supervision of field staff; a high-quality door-to-door vaccination strategy; multiple visits to homes; and monitoring of vaccine coverage by household during the course of the campaigns.

Monitoring measles eradication in the region of the Americas: critical activities and tools.

The purpose of this paper is to discuss methods recommended and used by the Pan American Health Organization (PAHO) to monitor the interruption of indigenous measles transmission in the Region of the Americas. The methods used include house-to-house monitoring of vaccination coverage as a supervisory tool during both campaigns and routine vaccination; thoroughly investigating all measles outbreaks; performing routine surveillance, including weekly reporting from at least 80% of reporting units; and validating routine surveillance through active-case searches at health care institutions and schools and in the community. The strategies described have helped PAHO to increase the authority and accountability of vaccine program managers at the local, provincial, and national levels. Their efforts have permitted the Region of the Americas to reduce to three the number of countries with indigenous measles transmission and to reach a record low of 503 measles cases in 2001.

The Measles Laboratory Network in the region of the Americas.

The success of measles eradication depends upon a laboratory network to rapidly analyze samples obtained as part of surveillance and case investigation. The Pan American Measles Laboratory Network was established in 1995. Major activities of the 22 participating laboratories include the rapid testing of serum samples to diagnose measles, analysis and recommendation of techniques to be used in serologic testing, training in virus isolation, and procurement and distribution of laboratory materials. In addition, a comprehensive quality-control program and an electronic communication network have been developed. Testing for rubella has also been incorporated. The Network has been crucial to the great progress made toward eradicating measles from the Western Hemisphere. The priority given to the laboratories in the Network must continue in order to ensure that the eradication goal is reached and that validation of the interruption of endemic transmission of measles is documented.

Prevalence of hepatitis A virus infection among sewage workers in Georgia.

BACKGROUND: Wastewater (WW) workers could have opportunity for direct contact with raw sewage, which might contain hepatitis A virus (HAV). METHODS: A serologic survey of WW workers and a comparison population of roads and drainage workers (RD). Factors potentially associated with anti-HAV positivity were evaluated in univariate and multivariate analyses. RESULTS: Among the 365 WW workers, overall anti-HAV prevalence was 38%, similar to that (35%) of the 166 RD workers (P = 0.5). Prevalence varied by wastewater job type from 45% among the 164 field crew workers to 32% among the 201 treatment plant workers. In multivariate modeling, factors associated with anti-HAV positivity included age > or = 40 years (odds ratio [OR] = 2.4; 95% CI = 1.6-3.7), black compared to other races (OR = 2.4; 95% CI = 1.5-3.8), birth outside the United States (OR = 7.5; 95% CI = 3.0-18.6), a high school education or less (OR 2.1; 95% CI = 1.4-3.2) and work on the field crew compared to RD work (OR 1.6; 95% CI = 1.1-2.4). CONCLUSIONS: These results are consistent with no or a small increased risk of hepatitis A among WW workers, and do not provide a clear mandate for hepatitis A vaccination of these workers. Am. J. Ind. Med. 43: 172-178, 2003.

Outbreak of poliomyelitis in Hispaniola associated with circulating type 1 vaccine-derived poliovirus.

An outbreak of paralytic poliomyelitis occurred in the Dominican Republic (13 confirmed cases) and Haiti (8 confirmed cases, including 2 fatal cases) during 2000-2001. All but one of the patients were either unvaccinated or incompletely vaccinated children, and cases occurred in communities with very low (7 to 40%) rates of coverage with oral poliovirus vaccine (OPV). The outbreak was associated with the circulation of a derivative of the type 1 OPV strain, probably originating from a single OPV dose given in 1998-1999. The vaccine-derived poliovirus associated with the outbreak had biological properties indistinguishable from those of wild poliovirus.

Brote de poliomielitis en Haiti y la Republica Dominicana debido a un virus derivado de la vacuna antipoliomielitica oral / Poliomyelitis outbreak caused by vaccine-derived virus in Haiti and the Dominican Republic

In October 2000, the Ministries of Helth of the Dominican Republic and Haiti notified two cases of acute flaccid paralyis (AFP) in rural areas, one of them in a 9-month-old female, and the other in a 2-year-old female, respectively. Stool samples that were obtained from these cases, which occured in July and August 2000, after a 9-year interruption of wild poliovirus circulation in the Western Hemisphere, revealed the presence of type 1 poliovirus. Genetic sequencing, which was later performed at the CEnters for Disease Control and Prevention, in Atlanta, Georgia, United States of America, revealed an atypical descendant of the virus used in the manufacture of the oral polio vaccine (OPV), but with 3 percent genetic divergence with respect to the parent strain. Normally, viral isolates that derive from vaccine components show 99.5 percent genetic agreement with the parent strain; in wild polioviruses, on the other hand, this agreement is usually less than 82.0 percent. Thus, the 3 percent genetic divergence detected in this study suggests that, in areas with low vaccine coverage, the virus used in the vaccine remained in circulation for at least two years, during which it recovered the neurovirulence and communicability of wild poliovirus type 1. This report describes the characteristics and results of the active search for cases of AFP that was sparked by the detection of the two index cases. It also looks at the public health implications of this outbreak for the entire Region of the Americas (AU)

Brote de poliomielitis en Haití y la Republica Dominicana debido a un virus derivado de la vacuna antipoliomielítica oral / Poliomyelitis outbreak caused by vaccine-derived virus in Haiti and the Dominican Republic

In October 2000, the Ministries of Health of the Dominican Republic and Haiti notified two cases of acute flaccid paralysis (AFP) in rural areas, one of them in a 9-month-old female, and the other in a 2-year-old female, respectively. Stool samples that were obtained from these cases, which ocurred in July and August 2000, after a 9-year interruption of wild poliovirus circulation in the Western Hemisphere, revealed the presence of type 1 poliovirus. Genetic sequencing, whith was later performed at the Centers for Disease Control and Prevention, in Atlanta, Georgia, United States of America, revealed an atypical descendant of the virus used in the manufacture of the oral polio vaccine (OPV), but with 3 genetic divergence with respect to the parent strain, in wild polioviruses, on the other hand, this agreement is usually less than 82.0. Thus, the 3 genetic divergence detected in this study suggests that, in areas with low vaccine coverage, the virus used in the vaccine remained in circulation for at least two years, during which it recovered the neurovirulence and communicability of wild poliovirus type 1. This report describes the characteristics and result of the active search for cases of AFP that was sparked by the detection of the two index cases. It also looks at the public health implications of this oatbreak for the entire Region of the Americas