RESUMO
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.
Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Sarampo , Humanos , Uganda/epidemiologia , Pré-Escolar , Sarampo/epidemiologia , Sarampo/virologia , Lactente , Criança , Masculino , Feminino , Adolescente , Vírus/isolamento & purificação , Vírus/genética , Vírus/classificação , Genoma Viral , Adulto , Adulto Jovem , Viroses/epidemiologia , Viroses/virologia , Metagenômica , Vírus do Sarampo/genética , Vírus do Sarampo/isolamento & purificação , Vírus do Sarampo/classificaçãoRESUMO
Le Dantec virus (LDV), assigned to the species Ledantevirus ledantec, genus Ledantevirus, family Rhabdoviridae has been associated with human disease but has gone undetected since the 1970s. We describe the detection of LDV in a human case of undifferentiated fever in Uganda by metagenomic sequencing and demonstrate a serological response using ELISA and pseudotype neutralisation. By screening 997 individuals sampled in 2016, we show frequent exposure to ledanteviruses with 76% of individuals seropositive in Western Uganda, but lower seroprevalence in other areas. Serological cross-reactivity as measured by pseudotype-based neutralisation was confined to ledanteviruses, indicating population seropositivity may represent either exposure to LDV or related ledanteviruses. We also describe the discovery of a closely related ledantevirus in blood from the synanthropic rodent Mastomys erythroleucus. Ledantevirus infection is common in Uganda but is geographically heterogenous. Further surveys of patients presenting with acute fever are required to determine the contribution of these emerging viruses to febrile illness in Uganda.
Assuntos
Anticorpos Antivirais , Rhabdoviridae , Humanos , Uganda/epidemiologia , Adulto , Masculino , Feminino , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Anticorpos Antivirais/sangue , Criança , Rhabdoviridae/isolamento & purificação , Rhabdoviridae/genética , Rhabdoviridae/classificação , Pré-Escolar , Infecções por Rhabdoviridae/epidemiologia , Infecções por Rhabdoviridae/virologia , Infecções por Rhabdoviridae/veterinária , Estudos Soroepidemiológicos , Animais , Reações Cruzadas , Lactente , Idoso , Filogenia , Ensaio de Imunoadsorção Enzimática , MetagenômicaRESUMO
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.