RESUMO
Noroviruses constitute a significant aetiology of sporadic and epidemic gastroenteritis in human hosts worldwide, especially among young children, the elderly, and immunocompromised patients. The low infectious dose of the virus, protracted shedding in faeces, and the ability to persist in the environment promote viral transmission in different socioeconomic settings. Considering the substantial disease burden across healthcare and community settings and the difficulty in controlling the disease, we review aspects related to current knowledge about norovirus biology, mechanisms driving the evolutionary trends, epidemiology and molecular diversity, pathogenic mechanism, and immunity to viral infection. Additionally, we discuss the reservoir hosts, intra-inter host dynamics, and potential eco-evolutionary significance. Finally, we review norovirus vaccines in the development pipeline and further discuss the various host and pathogen factors that may complicate vaccine development.
RESUMO
Gastroenteritis viruses are the leading etiologic agents of diarrhea in children worldwide. We present data from thirty-three (33) eligible studies published between 2003 and 2023 from African countries bearing the brunt of the virus-associated diarrheal mortality. Random effects meta-analysis with proportion, subgroups, and meta-regression analyses were employed. Overall, rotavirus with estimated pooled prevalence of 31.0 % (95 % CI 24.0-39.0) predominated in all primary care visits and hospitalizations, followed by norovirus, adenovirus, sapovirus, astrovirus, and aichivirus with pooled prevalence estimated at 15.0 % (95 % CI 12.0-20.0), 10 % (95 % CI 6-15), 4.0 % (95 % CI 2.0-6.0), 4 % (95 % CI 3-6), and 2.3 % (95 % CI 1-3), respectively. Predominant rotavirus genotype was G1P[8] (39 %), followed by G3P[8] (11.7 %), G9P[8] (8.7 %), and G2P[4] (7.1 %); although, unusual genotypes were also observed, including G3P[6] (2.7 %), G8P[6] (1.7 %), G1P[6] (1.5 %), G10P[8] (0.9 %), G8P[4] (0.5 %), and G4P[8] (0.4 %). The genogroup II norovirus predominated over the genogroup I-associated infections (84.6 %, 613/725 vs 14.9 %, 108/725), with the GII.4 (79.3 %) being the most prevalent circulating genotype. In conclusion, this review showed that rotavirus remains the leading driver of viral diarrhea requiring health care visits and hospitalization among under-five years children in Africa. Thus, improved rotavirus vaccination in the region and surveillance to determine the residual burden of rotavirus and the evolving trend of other enteric viruses are needed for effective control and management of cases.
Assuntos
Gastroenterite , Humanos , Gastroenterite/virologia , Gastroenterite/epidemiologia , Pré-Escolar , Lactente , África/epidemiologia , Prevalência , Diarreia/virologia , Diarreia/epidemiologia , Rotavirus/genética , Rotavirus/isolamento & purificação , Rotavirus/classificação , Recém-Nascido , Genótipo , Viroses/epidemiologia , Viroses/virologia , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia , Vírus/classificação , Vírus/genética , Vírus/isolamento & purificaçãoRESUMO
BACKGROUND: Continuing the administration of magnesium sulphate for 24 hours after the last fit in patients with eclampsia is at best empirical. The challenge of such a regimen is enormous in low-resource countries. The objective of this study was to assess the effectiveness of an ultra-short regimen of magnesium sulphate in eclamptics. FINDINGS: This was a prospective, cohort study of eclamptic patients admitted between July 2007 and June 2008 that were given 4 grams magnesium sulphate intravenously and 10 grams intramuscularly (5 grams in each buttock) as the sole anticonvulsant agent. Main outcome measure was the absence of a repeat fit. Other aspects of eclampsia management were as in standard practice. One hundred and twenty one (121) patients were managed with this regimen. There were 29 ante partum, 76 intrapartum and 16 post partum cases of eclampsia. Most of the patients were primigravidae (100; 83%) with an average age of 18.7 years. There were nine cases (7.4%) of recurrent fits that occurred within four hours of the loading dose. One recurrent fit occurred in the ante partum group, seven in the intra partum and one in the post partum group. There were 12 maternal deaths giving a case fatality rate of 9.9%. CONCLUSION: Limiting the dosage of magnesium sulphate to 14 grams loading dose (4 grams intravenous and 10 grams intramuscular) was effective in controlling fits in 92.6% of cases in the study group. A properly conducted, randomized controlled trial is needed to test our proposed regimen.