This site needs JavaScript to work properly. Please enable it to take advantage of the complete set of features!
Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

NIH NLM Logo
Log in
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Sep;99(3_Suppl):26-33.
doi: 10.4269/ajtmh.18-0125. Epub 2018 Jul 24.

Typhoid Fever in Chile 1969-2012: Analysis of an Epidemic and Its Control

Affiliations

Typhoid Fever in Chile 1969-2012: Analysis of an Epidemic and Its Control

Claudia Marco et al. Am J Trop Med Hyg. 2018 Sep.

Abstract

From 1975 to 1983, a large epidemic of typhoid fever (TF) affected the metropolitan region (MR) of Chile (incidence rate [IR] of 219.6 per 105 in 1983). In 1983-1984, interventions were implemented focusing on person-to-person transmission (vaccination, food handlers' control, and mass communication) and regulations to control irrigation waters containing fecal contaminates. In 1991, a second intervention was quickly implemented to avoid the cholera epidemic affecting neighboring countries (total prohibition of growing or selling crops in the MR). We explored the potential impact of these interventions on the epidemic. We created a yearly database of the MR TF cases, population, and contextual factors of TF from 1969 to 2012. We first analyzed the epidemic (Joinpoint regression), identified predictors of TF (Poisson multiple regression), and then analyzed the effect of the interventions (interrupted time series model). The main predictor of the TF epidemic was the rate of unemployment. In relation to the 1983-1984 person-to-person interventions, TF came down by 51% (95% confidence interval [CI]: 30.2-65.0%) and continued to decrease at a rate of 10.4% (95% CI: 5.8-15.6%) per year until 1991. In 1991, with the strong environmental control of the sewage-irrigated crops, TF further decreased by 77% (95% CI: 69.0-83.1%) and continued decreasing thereafter at 13% (95% CI: 11.3-15.6%) per year until the end of the study period. Today, 40 years after the epidemic, TF is a rare disease in the MR of Chile.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Typhoid fever incidence in the metropolitan region (MR) and the rest of Chile, 1950–2012. The orange line depicts typhoid incidence trends per 100,000 persons in the MR of Chile. The hashed blue line shows the trend in typhoid incidence per 100,000 persons in the rest of Chile.
Figure 2.
Figure 2.
Typhoid fever (TF) incidence trend in the metropolitan region of Chile Joinpoint regression 1950–2012. Best joinpoint model. ^ indicates that the average percent change (APC) is significantly different from zero at alpha = 0.05 level. The squares represent the observed rates per 100,000 persons of TF across the study period (1950–2012). The dark blue line is the joinpoint model from 1950 to 1975. The dark green line is the joinpoint model from 1975 to 1978. The red line shows the joinpoint model from 1978 to 1983. The turquoise line shows the joinpoint model from 1983 to 2012. Note: The joinpoint model is a Poisson model that, unlike the interrupted time series, does not incorporate level changes and only changes in the slope. It looks for points where the slope breaks. To estimate a slope, it requires at least two intermediate points between breakpoints.
Figure 3.
Figure 3.
Typhoid fever (TF) observed incidence rates (IRs) in the metropolitan region and interrupted time series model fit. Typhoid fever observed IRs per 100,000 persons between 1969 and 2010 are shown with the open circles. Predicted TF IRs within the same time period per 100, 000 persons is shown as a line of best fit. Gray bands represent the area of effect of each intervention. The darkest band represents Intervention 1.

Comment in

  • Typhoid Fever in Chile.
    Cabello F. Cabello F. Am J Trop Med Hyg. 2018 Dec;99(6):1649-1650. doi: 10.4269/ajtmh.18-0677. Am J Trop Med Hyg. 2018. PMID: 30851026 Free PMC article. No abstract available.

References

    1. Enrique L, Ferreccio C, 2007. Fiebre tifoidea: emergencia, cúspide y declinación de una enfermedad infecciosa en Chile. Rev Chilena Infectol 24: 435–440. - PubMed
    1. Ernesto M, Yrarrazaval M, 1983. Fiebre tifoidea en Chile: consideraciones epidemiológicas. Rev Med Chil 111: 606–615. - PubMed
    1. Ricardo AA, Donoso P, 1990. Desarrollo socioeconómico de Chile: un análisis comparativo para América del Sur. Cuad Econ 27: 31–81.
    1. Ristori C, 1981. Epidemiologia de la fiebre tifoidea en Chile. Boletín de Vigilancia Epidemiológica 8: 8–11
    1. Superintendencia de Servicios Sanitarios (SISS) , 2015. Cobertura Histórica del Sector. Available at: http://www.siss.gob.cl/577/w3-article-3683.html. Accessed July 1, 2018.

Publication types

LinkOut - more resources

Cite

AltStyle によって変換されたページ (->オリジナル) /