Trends in Infectious Disease Mortality Rates, Spain, 1980–2011

Teresa López-Cuadrado

, Alicia Llácer, Rocio Palmera-Suárez, Diana Gómez-Barroso, Camelia Savulescu, Paloma González-Yuste, and Rafael Fernández-Cuenca

Author affiliations: Carlos III Institute of Health, Madrid, Spain (T. López-Cuadrado, A. Llácer, R. Palmera-Suárez, D. Gómez-Barroso, C. Savulescu, P. González-Yuste, R. Fernández-Cuenca);Centros de Investigación Biomédica en Red de Epidemiología y Salud Pública, Madrid (A. Llácer, R. Palmera-Suárez, D. Gómez-Barroso, R. Fernández-Cuenca); Complejo Hospitalario de Toledo, Toledo, Spain (P. Gónzalez-Yuste)

Abstract

Using mortality data from National Institute of Statistics in Spain, we analyzed trends of infectious disease mortality rates in Spain during 1980–2011 to provide information on surveillance and control of infectious diseases. During the study period, 628,673 infectious disease–related deaths occurred, the annual change in the mortality rate was −1.6%, and the average infectious disease mortality rate was 48.5 deaths/100,000 population. Although the beginning of HIV/AIDS epidemic led to an increased mortality rate, a decreased rate was observed by the end of the twentieth century. By codes from the International Classification of Diseases, 9th revision, the most frequent underlying cause of death was pneumonia. Emergence and reemergence of infectious diseases continue to be public health problems despite reduced mortality rates produced by various interventions. Therefore, surveillance and control systems should be reinforced with a goal of providing reliable data for useful decision making.

Although infectious diseases continue to account for considerable illness and death worldwide (1,2), mortality rates for these diseases in industrialized countries decreased considerably by end of the twentieth century (1–4). The decrease in infectious disease mortality rates was caused by a set of complex factors fundamentally linked to development, such as better sanitation as populations became more urban, and improvements in infrastructure, nutrition, and biotechnological advances, particularly in the field of vaccines and antimicrobial drugs (5). This reduction was reflected mainly in the decrease of child mortality rates. At the beginning of the twentieth century, 30% of all deaths caused by infectious diseases were among children <5 years of age; by the end of the twentieth century, these diseases accounted for only 1.4% of all deaths (3). In the 1980s, the decreasing trend of the infectious disease mortality rate in industrialized countries was interrupted by the HIV/AIDS epidemic, which confronted the scientific community and health authorities with the challenge of a new emerging infection that has still not been controlled.

In Spain, as in other industrialized countries, mortality rates decreased overall and for children over the course of the twentieth century, life expectancy increased dramatically. The progressive decrease in deaths from infectious causes was interrupted by the HIV/AIDS epidemic, which changed the trend and pattern of infectious diseases for the population overall and for specific age groups affected (6). New antiretroviral therapies introduced in the mid-1990s decreased deaths caused by HIV/AIDS, as well as deaths caused by other infectious diseases. However, other threats to human health related to emergence and reemergence of infectious disease have arisen (7), mainly because of environmental and climate changes, travel and trade, human behavior, new technologies, microbial adaptation, and host-impaired immunity (8). These continuous threats make specific infectious disease surveillance and control programs even more necessary (8).

All-cause and cause-specific mortality rates, as well as standardized mortality rates, are still good indicators for ascertaining the public health effects of a given disease and assessing trends in incidence. Successive revisions of the International Classification of Diseases (ICD) have continued to apply an etiologic criterion to pool part of infectious and parasitic diseases in a single group and leaving conditions of infectious origin in other groups. Pinner et al. (9) found that ICD codes for infectious and parasitic diseases in the ICD, 9th revision (ICD-9) included only 67% of the 1,131 codes that could be included as infectious diseases or consequences of infections, and applied comprehensive criteria to the analysis of infectious disease mortality rates. In Spain, infectious disease mortality rates in the early 1990s were assessed by using similar criteria and resulted in a 3-fold increase in number of deaths related to ICD codes for infectious and parasitic diseases (6,10). The purposes of the current study were to determine the magnitude of infectious disease mortality rates rate overall and by sex, age, and the principal causes implicated, and to describe trends during 1980–2011 to clarify surveillance needs and enhance control strategies.