Monitoring the evolution of vaccine-derived poliovirus in East and Southern African countries, 2010 - 2021.

Introduction: the Africa region was certified indigenous wild poliovirus-free in August 2020. Countries in East and Southern Africa have, during acute flaccid paralysis (AFP) and environmental surveillance (ES), detected equally concerning vaccine-derived polioviruses (VDPVs) that have not been systematically documented to guide programming in the sub-region. The study documents trends and salient observations of the VDPVs by country of detection, for 11 years from 2010 to 2021. Methods: we conducted secondary data analysis, a descriptive study design, by deploying field and laboratory of AFP and environmental surveillance databases of the 20 East and Southern African countries from 2010 to 2021. Results: a total of 318 VDPVs were reported over the study period. The majority were from AFP cases (58.8%) and the rest equally distributed between healthy community children and environmental surveillance sources. More polioviruses were detected after 2016 than during the period before. We observed that more boys were affected by VDPVs compared to girls. Children under 5 years were more affected than other age groups, with a mean age of 3.6 years. Delay of samples in the field seemed to increase the likelihood of not reporting VDPVs and not mounting timely public health detailed investigations and vaccination responses. Conclusion: the study provides useful evolutional trends of VDPVs for surveillance and vaccination programming. We also noted that the VDPV2s have been increasing after the 2016 tOPV to oral polio vaccine (bOPV) switch. The COVID-19 pandemic emergence in 2020, led to a decline in AFP, ES surveillance, and immunization activities. Our findings point to the need to implement enhanced tailored childhood immunization recovery strategies and to speed up the use of inactivated polio vaccine (IPV) to boost population immunity.

Rubella virus genotype 2B endemicity and related utility of serum-based molecular characterization in Uganda.

There are 13 globally recognized rubella virus genotypes of which only 2 (1E and 2B) have been detected recently. The largest percentage of all reported rubella virus sequences come from China and Japan with Africa reporting limited data. In a bid to address the lack of rubella genotype data in Uganda and the World Health Organization Africa region, we sought to characterize rubella viruses retrospectively using sera collected from suspected measles patients that turned out rubella IgM positive.Seven sequences belonging to genotype 2B sub-lineage 2B-L2c were obtained. These sequences clustered with other genotype 2B sequences previously reported from Uganda. None of the other genotypes (1E and 1G) reported from Uganda in the earlier years were detected. In addition, none of the sequences were obtained after the introduction of the measles-rubella containing vaccine. The above highlight the need for continuous rubella virological surveillance to confirm interruption of endemic rubella genotype circulation.

Sabin polio virus protein 1 (VP1) evolution in patients with acute flaccid paralysis from 2010 to 2016 in Uganda.

Acute flaccid paralysis (AFP) is a rare side effect of the oral polio vaccine but can be associated with outbreaks and permanent disability in patients harboring circulating vaccine-derived polioviruses (cVDPVs). With the advancement of polio abolition in a glimpse, cVDPVs are causing outbreaks and slowing the polio eradication process. The polio virus protein 1 (VP1) contains the binding site that is key for virus transmission. Understanding the evolution of VP1 among AFP patients could yield more insight into the early events of cVDPVs. Polioviruses were identified from stool specimens of AFP patients using cell culture; and confirmed by the real time RT PCR intra-typic differentiation and vaccine-derived poliovirus assays. Seventy-nine (79) Sabin-like poliovirus 1 (SL1) and 86 Sabin-like poliovirus 3 (SL3) were sequenced. The VP1 amino acid substitutions T106A in Sabin poliovirus 1 and A54V in Sabin poliovirus 3 were common among the AFP patients as has been found in previous studies. Other substitutions that were associated with AFP were: T290A and A54T in SL1 and SL3 respectively. Nucleotide mutations that were common among the AFP patients included T402C, C670A, and T816C in SL1, and G22A, C375Y, A472R, and A694T in SL3 polioviruses. Characterizing mutations that are associated with AFP could contribute to efforts pursued to mitigate the risk of vaccine-derived polioviruses and promote development of safer vaccines.

Environmental surveillance detects circulating vaccine-derived poliovirus type 2 that was undetected by acute flaccid paralysis surveillance in 2021 in Uganda.

The success of the global polio eradication initiative is threatened by the genetic instability of the oral polio vaccine, which can result in the emergence of pathogenic vaccine-derived polioviruses following prolonged replication in the guts of individuals with primary immune deficiencies or in communities with low vaccination coverage. Through environmental surveillance, circulating vaccine-derived poliovirus type 2 was detected in Uganda in the absence of detection by acute flaccid paralysis (AFP) surveillance. This underscores the sensitivity of environmental surveillance and emphasizes its usefulness in supplementing AFP surveillance for poliovirus infections in the race towards global polio eradication.

The road to a polio-free Uganda; contribution of the Expanded Program on Immunization Laboratory (EPI-LAB) at Uganda Virus Research Institute.

Background: The control of poliomyelitis in Uganda dates back as far as 1950 and acute flaccid paralysis (AFP) surveillance has since been used as a criterion for identifying wild polioviruses. Poliovirus isolation was initially pursued through collaborative research however, in 1993, the Expanded Program on Immunization Laboratory (EPI-LAB) was established as a member of the Global Poliovirus Laboratory Network (GPLN) and spearheaded this activity at Uganda Virus Research Institute. Objectives: The aim of this report is to document the progress and impact of the EPI-LAB on poliovirus eradication in Uganda. Methods: Poliovirus detection and identification were achieved fundamentally through tissue culture and intra-typic differentiation of the poliovirus based on the real-time reverse transcriptase polymerase chain reaction (rRT PCR). The data obtained was entered into the national AFP database and analysed using EpiInfoTM statistical software. Results: Quantitative and qualitative detection of wild and Sabin polioviruses corresponded with the polio campaigns. The WHO target indicators for AFP surveillance were achieved essentially throughout the study period. Conclusion: Virological tracking coupled with attaining standard AFP surveillance indicators has been pivotal in achieving and maintaining the national wild polio-free status. Laboratory surveillance remains key in informing the certification process of polio eradication.

The impact of the COVID-19 pandemic on measles surveillance in the World Health Organisation African Region, 2020.

INTRODUCTION: following the declaration of the COVID-19 pandemic, many countries imposed restrictions on public gatherings, health workers were repurposed for COVID-19 response, and public demand for preventive health services declined due to fear of getting COVID-19 in health care settings. These factors led to the disruption in health service delivery, including childhood immunization, in the first months of the pandemic. Measles surveillance supported with laboratory confirmation, is implemented in the African Region as part of the strategies towards attaining measles elimination. World Health Organisation developed guidelines to assist countries to continue to safely provide essential health services including immunization and the surveillance of vaccine preventable diseases during the pandemic. METHODS: we analysed the measles case-based surveillance and laboratory databases for the years 2014 to 2020, to determine the impact of the COVID-19 pandemic on measles surveillance, comparing the performance in 2020 against the preceding years. RESULTS: the weekly reporting of suspected measles cases declined starting in April 2020. Twelve countries had more than 50% decline in both the number of reported cases as well as in the number of specimens collected in 2020, as compared to the mean for the years 2014-2018. In 2020, only 30% of the specimens from suspected measles cases arrived at the national laboratory within 3 days of collection. At Regional level, 86% of the districts reported suspected measles cases in 2020, while the non-measles febrile rash illness rate was 2.1 per 100,000 population, which was the lowest rate documented since 2014. Only 11 countries met the targets for the two principal surveillance performance indicators in 2020 as compared to an average of 21 countries in the years 2014-2019. CONCLUSION: the overall quality of measles surveillance has declined during the COVID pandemic in many countries. Countries should implement immediate and proactive measures to revitalise active surveillance for measles and monitor the quality of surveillance. We recommend that countries consider implementing specimen collection and testing methods that can facilitate timely confirmation of suspected measles cases in remote communities and areas with transportation challenges.

Early effects of the COVID-19 pandemic on the acute flaccid paralysis surveillance in East and Southern African countries.

INTRODUCTION: the World health organisation (WHO) African Region reported the first confirmed COVID-19 case caused by the SARS-CoV-2 on 25th February 2020, and the first case for the East Southern Africa (ESA) sub-region was on 5th March 2020. Almost all countries in the ESA sub region implemented the WHO-recommended preventive measures variably after the notification of community transmission of the COVID-19 disease. This resulted in the disruption of the outpatient, immunization surveillance, and the related supply chain activities. METHODS: a comparative analysis study design of secondary acute flaccid paralysis (AFP) surveillance data received from the East and Southern Africa sub-region countries to evaluate the effect of the COVID-19 pandemic in the AFP field surveillance for the same time period of March to December 2019 and 2020. RESULTS: we observed that 52.4% of second stool samples were received in the laboratory within 72 hours from March to December 2019, and only 48.1% in the same period of 2020. A 4.3% decline with a p-value of <0.0001 (95% CI, ranges from 2.326% to 6.269%). Similarly, we noted a 4.7% decline in the number of reported AFP cases in the ESA sub-region for March to December 2020 compared to the same period in 2019, a p-value of less than 0.001 (95% CI ranges from 2.785 to 6.614). For the percentage of stool adequacy, we observed a 3.37% decline for April in 2020 compared to April 2019 with a p-value of less than 0.001 (95% CI ranges from 2.059 to 4.690). CONCLUSION: we observed a decline in the core AFP surveillance (non polio) NP-AFP rate, and percentage of stool adequacy in countries severely affected by the COVID-19 disease. These countries implemented stringent transmission prevention measures such as lock-down and international transportation restrictions.

Assessment of acute flaccid paralysis surveillance performance in East and Southern African countries 2012 - 2019.

INTRODUCTION: polio eradication initiatives started in 1988, this is almost the past 32 years following the WHA resolution 41.8 of eradicating polio by the year 2000. As of 2019, only 3 countries remained to be polio endemic globally, Afghanistan, Pakistan and Nigeria. The east and southern sub-region countries had shown progressive achievement towards polio eradication and to start with the African regional certification. The availability of sensitive AFP surveillance performance is among important strategies in the achievement of polio eradication. We, therefore, decided to conduct this assessment of AFP performance from 2012 to 2019 in the ESA sub-region have evidence documentation and support the certification process of the WHO AFRO region. METHODS: we reviewed all reported acute flaccid paralysis (AFP) cases from 19 countries in the ESA sub region with the date of onset of paralysis from 1 January 2012 to 31 December 2019. The data were run to descriptive analysis based on the personal characteristics and AFP surveillance performance indicators parameters. RESULTS: a total of 46,014 AFP cases were reported from 19 countries in the ESA countries who were paralyzed from 1 January 2012 to 31 December 2019. The most affected age group was children aged 0 to 3 years old where 19,740 children with acute paralysis were reported representing 42.9% of the total reported AFP for the period. The overall assessment of the non-polio AFP rate, there is an increase from a rate of 2.7 in 2012 to 3.5 in 2019 per 100,000 population aged less than 15 years, reflects a significant change with a p-value of 0.040 (95% C.I. ranges from 0.035 to 1.564). Furthermore, the percentage of stool adequacy raised from 86.4% in 2012 to 88.5% in 2019, with an observed 2.1% difference and no significant change over the 8 years. CONCLUSION: we observed an overall increase in the sensitivity of the AFP surveillance performance for the ESA sub-region countries from 2012 to 2019 using the national performance indicators. The COVID-19 pandemic paused an operational challenge for AFP surveillance performances from 2020. A further subnational surveillance performance analysis is suggested.

Descriptive epidemiology of rubella disease and associated virus strains in Uganda.

Rubella virus causes a mild disease; however, infection during the first trimester of pregnancy may lead to congenital rubella syndrome (CRS) in over 80% of affected pregnancies. Vaccination is recommended and has been shown to effectively reduce CRS incidence. Uganda plans to introduce routine rubella vaccination in 2019. The World Health Organization recommends assessing the disease burden and obtaining the baseline molecular virological data before vaccine introduction. Sera collected during case-based measles surveillance from January 2005 to July 2018 were tested for rubella immunoglobulin M (IgM) antibodies. Sera from confirmed rubella outbreaks from January 2012 to August 2017 were screened using real-time reverse-transcription polymerase chain reaction (RT-PCR); for positive samples, a region within the E1 glycoprotein coding region was amplified and sequenced. Of the 23 196 suspected measles cases serologically tested in parallel for measles and rubella, 5334 (23%) were rubella IgM-positive of which 2710 (50.8%) cases were females with 2609 (96.3%) below 15 years of age. Rubella IgM-positive cases were distributed throughout the country and the highest number was detected in April, August, and November. Eighteen (18%) of the 100 sera screened were real-time RT-PCR-positive of which eight (44.4%) were successfully sequenced and genotypes 1G and 2B were identified. This study reports on the seroprevalence and molecular epidemiology of rubella. Increased knowledge of former and current rubella viruses circulating in Uganda will enhance efforts to monitor the impact of vaccination as Uganda moves toward control and elimination of rubella and CRS.

The detection of 3 ambiguous type 2 vaccine-derived polioviruses (VDPV2s) in Uganda.

BACKGROUND: The Oral Polio Vaccine (OPV or Sabin) is genetically unstable and may mutate to form vaccine-derived polioviruses (VDPVs). METHODS: In 2014, two VDPVs type 2 were identified during routine surveillance of acute flaccid paralysis (AFP) cases. Consequently, a retrospective VDPV survey was conducted to ensure that there was no circulating VDPV in the country. All Sabin poliovirus isolates identified in Uganda 6 months before and 6 months after were re-screened; Sabin 1 and 3 polioviruses were re-screened for Sabin 2 and Sabin 2 polioviruses were re-screened for VDPVs type 2. The Poliovirus rRT-PCR ITD/VDPV 4.0 assay and sequencing were used respectively. RESULTS: The first two VDPVs type2 were identified in Eastern Uganda and the third was identified during the survey from South-western Uganda. These regions had low OPV coverage and poor AFP surveillance indicators. CONCLUSION: The retrospective VDPV survey was a useful strategy to screen for VDPVs more exhaustively. Supplementary surveillance methods need to be encouraged.

Progress Toward Measles Elimination - African Region, 2013-2016.

In 2011, the 46 World Health Organization (WHO) African Region (AFR) member states established a goal of measles elimination* by 2020, by achieving 1) ≥95% coverage of their target populations with the first dose of measles-containing vaccine (MCV1) at national and district levels; 2) ≥95% coverage with measles-containing vaccine (MCV) per district during supplemental immunization activities (SIAs); and 3) confirmed measles incidence of <1 case per 1 million population in all countries (1). Two key surveillance performance indicator targets include 1) investigating ≥2 cases of nonmeasles febrile rash illness per 100,000 population annually, and 2) obtaining a blood specimen from ≥1 suspected measles case in ≥80% of districts annually (2). This report updates the previous report (3) and describes progress toward measles elimination in AFR during 2013-2016. Estimated regional MCV1 coverage† increased from 71% in 2013 to 74% in 2015.§ Seven (15%) countries achieved ≥95% MCV1 coverage in 2015.¶ The number of countries providing a routine second MCV dose (MCV2) increased from 11 (24%) in 2013 to 23 (49%) in 2015. Forty-one (79%) of 52 SIAs** during 2013-2016 reported ≥95% coverage. Both surveillance targets were met in 19 (40%) countries in 2016. Confirmed measles incidence in AFR decreased from 76.3 per 1 million population to 27.9 during 2013-2016. To eliminate measles by 2020, AFR countries and partners need to 1) achieve ≥95% 2-dose MCV coverage through improved immunization services, including second dose (MCV2) introduction; 2) improve SIA quality by preparing 12-15 months in advance, and using readiness, intra-SIA, and post-SIA assessment tools; 3) fully implement elimination-standard surveillance††; 4) conduct annual district-level risk assessments; and 5) establish national committees and a regional commission for the verification of measles elimination.

Polio Eradication Initiative (PEI) contribution in strengthening public health laboratories systems in the African region.

BACKGROUND: The laboratory has always played a very critical role in diagnosis of the diseases. The success of any disease programme is based on a functional laboratory network. Health laboratory services are an integral component of the health system. Efficiency and effectiveness of both clinical and public health functions including surveillance, diagnosis, prevention, treatment, research and health promotion are influenced by reliable laboratory services. The establishment of the African Regional polio laboratory for the Polio Eradication Initiative (PEI) has contributed in supporting countries in their efforts to strengthen laboratory capacity. On the eve of the closing of the program, we have shown through this article, examples of this contribution in two countries of the African region: Côte d'Ivoire and the Democratic Republic of Congo. METHODS: Descriptive studies were carried out in Côte d'Ivoire (RCI) and Democratic Republic of Congo (DRC) from October to December 2014. Questionnaires and self-administered and in-depth interviews and group discussions as well as records and observation were used to collect information during laboratory visits and assessments. RESULTS: The PEI financial support allows to maintain the majority of the 14 (DRC) and 12 (RCI) staff involved in the polio laboratory as full or in part time members. Through laboratory technical staff training supported by the PEI, skills and knowledge were gained to reinforce laboratories capacity and performance in quality laboratory functioning, processes and techniques such as cell culture. In the same way, infrastructure was improved and equipment provided. General laboratory quality standards, including the entire laboratory key elements was improved through the PEI accreditation process. CONCLUSION: The Polio Eradication Initiative (PEI) is a good example of contribution in strengthening public health laboratories systems in the African region. It has established strong Polio Laboratory network that contributed to the strengthening of capacities and its expansion to surveillance of other viral priority diseases such as measles, yellow fever, Influenza, MERS-CoV and Ebola. This could serve as lesson and good example of laboratory based surveillance to improving diseases prevention, detection and control in our middle and low income countries as WHO and partners are heading to polio eradication in the world.

Global Measles and Rubella Laboratory Network Support for Elimination Goals, 2010-2015.

In 2012, the World Health Assembly endorsed the Global Vaccine Action Plan (GVAP)* with the objective to eliminate measles and rubella in five World Health Organization (WHO) regions by 2020. In September 2013, countries in all six WHO regions had established measles elimination goals, and additional goals for elimination of rubella and congenital rubella syndrome were established in three regions (1). Capacity for surveillance, including laboratory confirmation, is fundamental to monitoring and verifying elimination. The 2012-2020 Global Measles and Rubella Strategic Plan of the Measles and Rubella Initiative(†) calls for effective case-based surveillance with laboratory testing for case confirmation (2). In 2000, the WHO Global Measles and Rubella Laboratory Network (GMRLN) was established to provide high quality laboratory support for surveillance (3). The GMRLN is the largest globally coordinated laboratory network, with 703 laboratories supporting surveillance in 191 countries. During 2010-2015, 742,187 serum specimens were tested, and 27,832 viral sequences were reported globally. Expansion of the capacity of the GMRLN will support measles and rubella elimination efforts as well as surveillance for other vaccine-preventable diseases (VPDs), including rotavirus, and for emerging pathogens of public health concern.

Trends of rubella incidence during a 5-year period of case based surveillance in Zimbabwe.

BACKGROUND: Rubella is a disease of public health significance owing to its adverse effects during pregnancy and on pregnancy outcomes. Women who contract rubella virus during pregnancy may experience complications such as foetal death or give birth to babies born with congenital rubella syndrome. Vaccination against rubella is the most effective and economical approach to control the disease, and to avoid the long term effects and high costs of care for children with congenital rubella syndrome as well as to prevent death from complications. Zimbabwe commenced rubella surveillance in 1999, despite lacking a rubella vaccine in the national Expanded Programme on Immunization, as per the World Health Organization recommendation to establish a surveillance system to estimate the disease burden before introduction of a rubella vaccine. The purpose of this analysis is to describe the disease trends and population demographics of rubella cases that were identified through the Zimbabwe national measles and rubella case-based surveillance system during a 5-year period between 2007 and 2011. METHODS: Data from the Zimbabwe National Measles Laboratory for the 5-year study period were analysed for age, sex, district of origin, seasonality, and rubella IgM serostatus. RESULTS: A total of 3428 serum samples from cases of suspected measles in all administrative districts of the country were received by the laboratory during this period. Cases included 51% males and 49% females. Of these, 2999 were tested for measles IgM of which 697 (23.2%) were positive. Of the 2302 measles IgM-negative samples, 865 (37.6%) were rubella IgM-positive. Ninety-eight percent of confirmed rubella cases were children younger than 15 years of age. Most infections occurred during the dry season. CONCLUSIONS: The national case-based surveillance revealed the disease burden and trends of rubella in Zimbabwe. These data add to the evidence for introducing rubella-containing vaccine into the national immunization programme.

Measles Elimination in the WHO African Region: Progress and Challenges

In 2001; countries in the African Region adopted the measles mortality reduction strategies recommended by the WHO and UNICEF. Following the significant reduction in measles cases and deaths with the implementation of the strategies; in 2011; the African Region adopted a measles elimination goal for 2020. To assess progress; performance was reviewed using estimates of the first dose of measles vaccine in routine immunization (MCV1); the reported coverage for measles supplementary immunization activities (SIAs); as well as surveillance data. During 2011-2013; regional MCV1 coverage was stagnant at around 74; while approximately 215 million children were reached in measles SIAs in 43 countries. Regional measles vaccination coverage has not increased and measles incidence has remained high in the past three years. Intensive efforts are required to ensure that routine immunization and SIAs provide high population immunity; and to increase the sensitivity of measles surveillance

Overview of the WHO Polio Laboratory Network in the African Region

The Polio Laboratory Network has always played a critical role in diagnosing poliovirus disease (poliomyelitis) and the detection of poliovirus transmission. In the new millennium; the strength of the laboratory network is often a direct reflection of the success of the Polio Eradication Initiative (PEI) programme. The network has taken advantage of new technologies that provide speedy turnaround times for results reporting thus contributing to the success of the PEI programme. This article presents a brief overview of the work of the network

Progress toward measles preelimination--African Region, 2011-2012.

In 2008, the 46 member states of the World Health Organization (WHO) African Region (AFR) adopted a measles preelimination goal to reach by the end of 2012 with the following targets: 1) >98% reduction in estimated regional measles mortality compared with 2000, 2) annual measles incidence of fewer than five reported cases per million population nationally, 3) >90% national first dose of measles-containing vaccine (MCV1) coverage and >80% MCV1 coverage in all districts, and 4) >95% MCV coverage in all districts by supplementary immunization activities (SIAs). Surveillance performance objectives were to report two or more cases of nonmeasles febrile rash illness per 100,000 population, one or more suspected measles cases investigated with blood specimens in ≥80% of districts, and 100% completeness of surveillance reporting from all districts. This report updates previous reports and describes progress toward the measles preelimination goal during 2011-2012. In 2012, 13 (28%) member states had >90% MCV1 coverage, and three (7%) reported >90% MCV1 coverage nationally and >80% coverage in all districts. During 2011-2012, four (15%) of 27 SIAs with available information met the target of >95% coverage in all districts. In 2012, 16 of 43 (37%) member states met the incidence target of fewer than five cases per million, and 19 of 43 (44%) met both surveillance performance targets. In 2011, the WHO Regional Committee for AFR established a goal to achieve measles elimination by 2020. To achieve this goal, intensified efforts to identify and close population immunity gaps and improve surveillance quality are needed, as well as committed leadership and ownership of the measles elimination activities and mobilization of adequate resources to complement funding from global partners.

Expansion of the global measles and rubella laboratory network 2005-09.

Enhancing measles surveillance with integration of epidemiologic and laboratory information is one of the key strategies for accelerated measles control and elimination. The World Health Organization (WHO) Global Measles and Rubella Laboratory Network (LabNet) has been developed since 2000 to currently include 690 laboratories serving 183 countries. The LabNet testing strategy follows well-validated, standardized procedures for confirming suspected cases and for monitoring measles and rubella virus transmission patterns. The strength of the LabNet is a strong quality assurance program that monitors the performance of all laboratories through annual proficiency testing and continuous assessment. In the 5-year period 2005-2009, the results of >1 million measles immunoglobulin M (IgM) tests have been reported by the LabNet and, in addition, sequence information on >7000 measles and 600 rubella viruses has been shared. Progress with the development of the LabNet during 2005-2009 is discussed.

Global distribution of measles genotypes and measles molecular epidemiology.

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.