Perfil radiológico dos doentes com mal de Pott observados em uma unidade hospitalar. Rev. Ang. de Ciênc. da Saúde. 2021Jul – Dez; 2 (2): 4 - 9
Province), and Hospital Central de Nampula (Nampula Province). ViNaDia surveillance system produces most ofthe data on the epidemiology of RVA in Mozambique. INS is the leading institution studying RVA in Mozambique 10 .For the sake of research, the reference mentioned above virology laboratory of INS has the country's state-of-the-art equipment for RVA analysis 7,15 , an integral component to achieve ViNaDia's goals. Manhiça Health ResearchCenter (CISM) also develops studies on RVA 10 . Another laboratory with comparable equipment in the Directoratefor Animal Sciences of the National Institute for Agricultural Research (IIAM) 8,9 .Nampula has registered the highest number of cases (see details in subsection 5.3) 7 . There are potentialexplanations for why this province presented most cases. For instance, (1) Nampula is the most populated province 12 , and (2) there are serious hygiene issues in Nampula's urban areas impacting the spread of diarrheic diseases 17 .A recent analysis of the epidemiology of Rotavirus in Nampula observed that piped water was associated withrotavirus infection and suggested that this can be related to the water network that is old and damaged, while inthe post-vaccine period age, year, and contact with different animals were associated with rotavirus infection 18 . Itwould be worthy of studying the epidemiology of RVA in the Novo Bairro area of Quelimane city, well-known as anurban area with very precarious sanitation and a history of cholera outbreak 30.Mussa et al. 19 reported cases in the cities of Maputo and Matola, RVA infection was reported by de Deus et al. 14 , in children less than five years old with diarrhea in Mavalane General Hospital (Maputo City) in 41.3% andManhiça District Hospital (Maputo Province) in 44.3% 14 . On the other hand, Langa et al. 11 reported RVA infectionsin Chókwè District (Gaza Province) in 24.0% 11 . Based on the ViNaDiA platform, RVA infection was reported in fourprovinces of the country: Maputo city (southern region of the country), Sofala, Zambézia (Center region of thecountry), and Nampula (Northern region of the country), ranging from 12.2% - 40.2% regardless to the vaccineintroduction period 14,20 .
Vaccination So far, there are four licensed vaccines for Rotavirus in the world: the pentavalent RotaTeq™, monovalentRotatrix™ (GlaxoSmithKline Biologicals, Rixansart, Belgium), Rotavac® (Bharat Biotech, India), and Rotasiil® (SerumInstitute of India Pvt. Ltd. India) 21 . Mozambique introduced Rotatrix™ in September 2015 as part of the NationalImmunization Program. The Instituto Nacional de Saúde and partner organizations have been assessing thevaccination outcomes. After vaccine introduction, there was a significant reduction in diarrhea hospitalization androtavirus infection, from 40.2% in 2014 to 13.5% in 2017, and reduction cases occurred in undernourished childrenfrom 42.7% to 12.2% 18 .
Susceptible groups RVA is frequent in children up to 5 years old, with a slight majority in male patients 18,22 . A study reportedthe median age of hospitalization of 9 months in 2014 and 11 in 2015 during the pre-vaccine period than tenmonths in 2016 and 2017 in the post-vaccine period. In Chókwè, Langa et al. 11 found 94.1% of children positivefor Rotavirus aged up to two years old. de Deus et al. 22 in Manhiça and Mavalane found 52.7% of RVA cases inchildren from 0 to 11 months. Similar results were found in a case-control study conducted in Manhiça, wherechildren under one year had an attributable fraction of 34.8% of RVA infection 23 . Thus, these findings suggestthat RVA infection is higher in children less than one year and decreases as they grow up.
Molecular characterization of RVA Mozambique uses the WHO’s algori thm for RVA detection and characterization 24 . Several studies on RVA usesELISA through the commercial kits, mainly Prospect Oxoid with a specificity of 99.2% (96% - 100%) and sensitivityof 100% (95% - 100%). Reverse-transcriptase polymerase chain reaction (RT-PCR) performs the molecularcharacterization of RVA based on two significant proteins, VP7 and VP4, which gives the genotype combination Gand P. The complete genome sequence is essential to perform the phylogenetic analysis and sequencescomparison.Globally the most common RVA genotypes are G1P[8], G2P[4], G3P[8], and G4P[8], being G1P[8] the mostprevalent 25,26 . Studies conducted before the introduction of the vaccine in Mozambique (2015) reported G12P[8],G1P[8], and G12P[6] as the most common genotypes in Chokwé, a rural area in the Southern region of Mozambique 27 . João et al. 28 , in a study conducted in rural (Manhiça) and urban (Maputo city) areas, found G2P[4] and G12P[6]as the most prevalent genotypes. However, after vaccine introduction, a high diversity of RVA genotypes was
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