Literature review to identify evidence of secondary transmission of pentavalent human-bovine reassortant rotavirus vaccine (RV5) strains to unvaccinated subjects.

BACKGROUND: Rotavirus is the leading cause of severe diarrhea in infants and young children. Live attenuated vaccines can lead to horizontal transmission with the risk of vaccine-derived disease in contacts. Transmission of pentavalent human-bovine reassortant rotavirus vaccine (RV5) strains leading to clinical disease was not well evaluated in the pivotal clinical trials, and only a few case reports have been described in the literature. METHODS: We performed a systematic literature review to investigate secondary transmission of RV5 strains to unvaccinated subjects globally. We searched Embase, Medline for English papers, CNKI, Wan Fang for Chinese papers, and other resources (i.e., conference papers with full text) from January 2005 to June 2021. Eligibility criteria for inclusion were original articles based on non-interventional studies (case-control studies, cohort studies, cross-sectional studies) using RV5 strain transmission as outcomes. Other study or publication types were excluded, such as pre-clinical studies, interventional studies and case reports. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used, and study quality was assessed using the Newcastle-Ottawa Scale (NOS) for cohort studies and the JBI checklist for cross-sectional studies to assess the risk of bias. RESULTS: The search generated 2,089 articles in total. Seven articles met all inclusion criteria, including six cohort studies and one cross-sectional study. All studies underwent quality assessment and complied with the quality criteria of the NOS or JBI checklist, respectively. Overall, none of the seven studies identified RV5 vaccine-type transmission to an unvaccinated population, in either hospitals or nurseries under a close contact environment. One study reported that 1% of unvaccinated infants had gastrointestinal symptoms, but all symptoms were attributed to other clinical conditions. CONCLUSIONS: We found no evidence of horizontal transmission of RV5 strains to unvaccinated infants in a context of a limited amount and the descriptive nature of the identified studies.

Influenza humana a H1N1: pandemia esperada / H1N1 human influenza: pandemic expected

La influenza es responsable de incremento en la morbilidad y mortalidad, del costo de las hospitalizaciones y de ausentismo escolar y laboral. Es producida por el virus de la influenza perteneciente a la familia Orthomixoviridae y es un virus ARN envuelto. El período de incubación va de 1 a 4 días. Las manifestaciones clínicas incluyen fiebre y varían desde conjuntivitis leve a neumonía grave con falla multiorgánica, hemorragia pulmonar, náuseas, vómito y diarrea. Se ha reportado pandemias importantes con cifras de defunciones alarmantes. La influencia AH1N1, actualmente circulante desde marzo del 2009, es el producto de la recombinación genética del virus de la influenza porcina euroasiática, influenza porcina de Norteamérica, influenza aviar no H5, e influenza humana. Hasta el 13 de septiembre del presente año la OMS ha notificado la apararición de más de 296471 casos y al menos 3486 defunciones. En la regtión de América se informa de más de 124126 casos con 2625 defunciones. Según el Ministerio de Salud, en Venezuela se informa de 5171 casos sospechosos, 1316 confirmados y 67 defunciones por influenza AH1N1, hasta el 17 de septiembre de 2009. El lavado frecuente de manos, aislamiento de los sospechosos, tratamiento con oseltamivir o zanamivir y la inmunización al personal susceptible al tener disponible la vacuna son medidas indispensables en la prevención de la diseminación de la pandemia.

Influenza impacts morbidity, mortality and health care costs. It causes school and work absenteeism. The responsible microorganisms are RNA viruses belonging to Orthomixoviridae family. Uncomplicated influenza begins after an incubation period of 1 to 4 days. Symptoms include fever, and in some cases mild conjunctivitis, but other patients have severe pneumonia with multiorgan failure, pulmonary bleeding, nausea, vomiting, and diarrhea. New influenza AH1N1 is a genetic recombination of Euro-Asian swine influenza virus, seasonal influenza virus, and H3N2 virus as the one isolated in Australia in 2007 (A/Brisbane/10/2007). As of September 13, 2009, the World Health Organization reported more than 296471 confirmed cases worldwide with at least 3486 deaths. In the Americas the figure reaches more than 124126 cases, and 2625 dealths. Venezuelan Ministry of Health has confirmed 1316 cases with 67 deaths. Regular hand hygiene measures, isolation of cases, oseltamivir or zanamivir therapy to suspected or confirmed cases, and vaccination of susceptible people once the new vaccines become available are all important prevention measures.