title: Estimating the Size of the HCV Infection Prevalence: A Modeling Approach Using the Incidence of Cases Reported to an Official Notification System.
abstract: In this paper we propose two methods to give a first rough estimate of the actual number of hepatitis C virus (HCV)-infected individuals (prevalence) taking into account the notification rate of newly diagnosed infections (incidence of notification) and the size of the liver transplantation waiting list (LTWL) of patients with liver failure due to chronic HCV infection. Both approaches, when applied to the Brazilian HCV situation converge to the same results, that is, the methods proposed reproduce both the prevalence of reported cases and the LTWL with reasonable accuracy. We use two methods to calculate the prevalence of HCV that, as a first, and very crude approximation, assumes that the actual prevalence of HCV in Brazil is proportional to the reported incidence to the official notification system with a constant denoted [Formula: see text]. In the paper we discuss the limitations and advantages of this assumption. With the two methods we calculated [Formula: see text], which reproduces both the reported incidence and the size of the LTWL. With the value of [Formula: see text] we calculated the prevalence I(a) (the integral of which resulted in 1.6 million people living with the infection in Brazil, most of whom unidentified). Other variables related to HCV infection (e.g., the distribution of the proportion of people aged a who got infected n years ago) can be easily calculated from this model. These new variables can then be measured and the model can be recursively updated, improving its accuracy.
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, and LIM01-HCFMUSP, Av.Dr. Arnaldo 455, São Paulo, CEP 01246-903, Brazil.
authors.forename: Marcos
authors.initials: M
authors.lastname: Amaku
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, and LIM01-HCFMUSP, Av.Dr. Arnaldo 455, São Paulo, CEP 01246-903, Brazil.|Hospital São Paulo and Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Marcelo Nascimento
authors.initials: MN
authors.lastname: Burattini
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, and LIM01-HCFMUSP, Av.Dr. Arnaldo 455, São Paulo, CEP 01246-903, Brazil.
authors.forename: Francisco Antonio Bezerra
authors.initials: FA
authors.lastname: Coutinho
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, and LIM01-HCFMUSP, Av.Dr. Arnaldo 455, São Paulo, CEP 01246-903, Brazil.|Florida International University, Miami, FL, USA.
authors.forename: Luis Fernandez
authors.initials: LF
authors.lastname: Lopez
authors.affiliation: Departamento de DST, AIDS e Hepatites Virais, Ministério da Saúde do Brazil, Brasília, Brazil.
authors.forename: Fabio
authors.initials: F
authors.lastname: Mesquita
authors.affiliation: Departamento de DST, AIDS e Hepatites Virais, Ministério da Saúde do Brazil, Brasília, Brazil.
authors.forename: Marcelo Contardo Moscoso
authors.initials: MC
authors.lastname: Naveira
authors.affiliation: Departamento de DST, AIDS e Hepatites Virais, Ministério da Saúde do Brazil, Brasília, Brazil.
authors.forename: Gerson Fernando Mendes
authors.initials: GF
authors.lastname: Pereira
authors.affiliation: Departamento de DST, AIDS e Hepatites Virais, Ministério da Saúde do Brazil, Brasília, Brazil.
authors.forename: Melina Érica
authors.initials: MÉ
authors.lastname: Santos
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, and LIM01-HCFMUSP, Av.Dr. Arnaldo 455, São Paulo, CEP 01246-903, Brazil. edmassad@dim.fm.usp.br.|London School of Hygiene and Tropical Medicine, London, UK. edmassad@dim.fm.usp.br.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Massad
mesh_terms: D001938:Brazil / Q000453:epidemiology; D018563:Disease Notification; D006526:Hepatitis C / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D016031:Liver Transplantation; D055641:Mathematical Concepts; D015233:Models, Statistical; D015995:Prevalence; D014850:Waiting Lists
keywords: Hepatitis C; Mathematical models; Notification system incidence; Prevalence