RESUMEN
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.
Asunto(s)
Enterovirus , Poliomielitis , Poliovirus , Humanos , Poliovirus/genética , Uganda/epidemiología , alfa-Fetoproteínas , Poliomielitis/epidemiología , Poliomielitis/prevención & control , Vacuna Antipolio Oral/efectos adversos , ParálisisRESUMEN
Enteroviruses (EVs) are RNA viruses that can cause many clinical syndromes including acute flaccid paralysis (AFP). Within the global polio laboratory network, EVs are categorized either as polioviruses or non-polio enteroviruses (NPEVs). Specific NPEVs have been described in polio-like residual paralytic events in AFP patients. Retrospective analysis of 112 NPEV isolates from AFP patients was performed and thirty one NPEV types were identified of which 91% were Enterovirus B and 9% were Enterovirus A species. The NPEVs were distributed across the country with most patients in the eastern region (41/89; 46.1%). The highest proportion of patients were children less than 5 years (77/89; 86.5%) and male patients were more common (54/89; 60.7%). Echovirus 11 (11/89; 12.4%) was frequently observed and phylogenetic analysis of these sequences revealed high diversity. Coxsackievirus B5 (CV-B5), CV-B6, E21, and EV-B69 were only seen in patients with residual paralysis. Analyses of the EV-A71 sequence indicated a unique genogroup.
Asunto(s)
Enfermedades Virales del Sistema Nervioso Central/virología , Infecciones por Enterovirus/virología , Enterovirus/genética , Enterovirus/aislamiento & purificación , Genotipo , Mielitis/virología , Enfermedades Neuromusculares/virología , Filogenia , Adolescente , Enfermedades Virales del Sistema Nervioso Central/epidemiología , Niño , Preescolar , Estudios Transversales , Enterovirus/clasificación , Infecciones por Enterovirus/epidemiología , Monitoreo Epidemiológico , Heces/virología , Femenino , Variación Genética , Humanos , Masculino , Mielitis/epidemiología , Enfermedades Neuromusculares/epidemiología , Poliomielitis/virología , Estudios Retrospectivos , Análisis de Secuencia de ADN , Factores Sexuales , Uganda/epidemiologíaRESUMEN
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.
Asunto(s)
Anticuerpos Antivirales/sangre , Virus de la Rubéola/clasificación , Rubéola (Sarampión Alemán)/epidemiología , Rubéola (Sarampión Alemán)/virología , Adolescente , Niño , Preescolar , Costo de Enfermedad , Brotes de Enfermedades/estadística & datos numéricos , Femenino , Genotipo , Humanos , Inmunoglobulina M/sangre , Incidencia , Masculino , Sarampión/epidemiología , Filogenia , Embarazo , Vacuna contra la Rubéola/inmunología , Uganda/epidemiologíaRESUMEN
OBJECTIVES: In this study, we investigated the causes of measles-like illnesses (MLI) in the Uganda national surveillance program in order to inform diagnostic assay selection and vaccination strategies. METHODS: We used metagenomic next-generation sequencing (M-NGS) on the Illumina platform to identify viruses associated with MLI (defined as fever and rash in the presence of either cough, coryza or conjunctivitis) in patient samples that had tested IgM negative for measles between 2010 and 2019. RESULTS: Viral genomes were identified in 87/271 (32%) of samples, of which 44/271 (16%) contained 12 known viral pathogens. Expected viruses included rubella, human parvovirus B19, Epstein Barr virus, human herpesvirus 6B, human cytomegalovirus, varicella zoster virus and measles virus (detected within the seronegative window-period of infection) and the blood-borne hepatitis B virus. We also detected Saffold virus, human parvovirus type 4, the human adenovirus C2 and vaccine-associated poliovirus type 1. CONCLUSIONS: The study highlights the presence of undiagnosed viruses causing MLI in Uganda, including vaccine-preventable illnesses. NGS can be used to monitor common viral infections at a population level, especially in regions where such infections are prevalent, including low and middle income countries to guide vaccination policy and optimize diagnostic assays.
Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Sarampión , Humanos , Uganda/epidemiología , Preescolar , Sarampión/epidemiología , Sarampión/virología , Lactante , Niño , Masculino , Femenino , Adolescente , Virus/aislamiento & purificación , Virus/genética , Virus/clasificación , Genoma Viral , Adulto , Adulto Joven , Virosis/epidemiología , Virosis/virología , Metagenómica , Virus del Sarampión/genética , Virus del Sarampión/aislamiento & purificación , Virus del Sarampión/clasificaciónRESUMEN
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.