The influence of the age-period-cohort effects on the temporal trend mortality from schistosomiasis in Brazil from 1980 to 2014

Abstract

Background Schistosomiasis is highly debilitating and related to poverty, leading to chronic health problems. This disease is important for public health due to the high prevalence, severity of clinical forms and heterogeneous spatial and temporal patterns. In Brazil, about 1.5 million people are at risk of infection with Schistosoma mansoni, with an annual average of 500 deaths. In this study, the temporal change in mortality was evaluated in relation to the effects of age, period and birth cohort, in Brazil and regions, from 1980 to 2014. Methods In this study, we analyzed the influence of age, period and birth cohort (APC effects) on the temporal evolution of schistosomiasis mortality in Brazil from 1980 to 2014, according to sex and geographic regions of the country. The death records were extracted from the SIM (Mortality Information System) of the DATASUS website (Department of National Health Informatics) of the Ministry of Health of Brazil. The temporal effects were estimated using Bayesian models and the INLA (Integrated Nested Laplace Approximations) method for parameter inference. Results More than 24 thousand deaths were registered in the analyzed period, mainly in men from the Northeast region. In Brazil, children under 14 years of age had protection against death from schistosomiasis. There was no significant effect for others ages. From 1990 to 1999, there was a protective effect for death from schistosomiasis and a null effect in the other periods. There was a decreasing trend in the risk of death among birth cohorts. The greatest risk was among people born from 1903 to 1912. There was a protective effect for death among people born after 1968. Men were at risk of death between 25 and 54 years old, while women were at risk after seventy years of age. The southern and central-western regions had a risk of death until 1989 and had a protective effect between1995 and 1999.

High schistosomiasis-related mortality in Northeast Brazil: trends and spatial patterns

“…Different mortality rates in males, as well as the higher prevalence of the disease in this group, justify the importance of specific actions for this population, as indicated in previous publications [19][20][21] . However, the labor market and the greater prominence of women also generate occupational risks for women, which may cause changes in the mortality patterns in the future 19 .…”

“…It is possible that some of these children migrated to other regions of Brazil or to urban areas of the same state or municipality, where they had no contact with S. mansoni. In contrast, those who persisted in areas of higher endemicity may have reinfected themselves and were more likely to develop more severe clinical forms, with potential progression to death 21,22 . This may also explain the maintenance of higher mortality rates in older people.…”

Fatores associados às formas graves e aos óbitos por esquistossomose e aplicação do linkage probabilístico nas bases de dados, Pernambuco, 2007–2017

“…No Brasil, com as ações do Programa de Controle da Esquistossomose (PCE), implantado na década de 1980, os índices de gravidade reduziram. Somado a isso, o avanço no conhecimento sobre a história natural da doença e a ampliação dos serviços de saúde, com diagnóstico e tratamento, acarretaram a redução da mortalidade e o aumento da sobrevida dos indivíduos infectados 7 . Contudo, a transmissão da doença é observada em 19 dos 27 estados, sendo considerado o país mais afetado pela esquistossomose nas Américas, com 42,9 milhões de pessoas sujeitas ao risco de infecção e aproximadamente 1,5 milhão de indivíduos infectados [8][9][10] .…”

Basic and associated causes of schistosomiasis-related mortality in Brazil: A population-based study and a 20-year time series of a disease still neglected

“…In Brazil, by virtue of the activities of the Schistosomiasis Control Program (PCE), there has been a significant reduction in schistosomiasis severity indicators in recent decades [ 3 ]. Additionally, the improvements in health service strategies, as diagnosis and mass treatment in endemic areas, have dropped the number of cases and deaths and increased life expectancy for ill patients [ 3 ]. Regardless all these measures, schistosomiasis remains endemic in many states, mainly in the Northeast region [ 4 , 5 ].…”

“…Furthermore, prior studies conducted by our group showed an increase in the schistosomiasis mortality rate in age groups above 60 years [ 4 , 6 ]. Thereby, it suggests the chronicity of the disease, a higher risk of association with comorbidities, and death [ 3 , 7 ].…”