Epidemiology of varicella in Mexico.

BACKGROUND

The epidemiological patterns of varicella-zoster virus (VZV) infection, which are strongly associated with climate, are characterized by more frequent infections occurring among children in temperate regions than in the tropics. In temperate regions, varicella exhibits a seasonal cyclic behavior in which the number of cases increases significantly during the winter and spring seasons, further supporting the role of environmental factors in disease transmission. However, the underlying mechanisms responsible for this distinctive behavior are not fully understood. In Mexico, information regarding the epidemiology of varicella is scarce, and the distribution of VZV infection has not been analyzed.

OBJECTIVES

In this article we investigate the epidemiological patterns of varicella in Mexico and their relationship with different environmental and demographic factors.

STUDY DESIGN

A retrospective study was conducted using the data reported by the National Center of Epidemiological Surveillance and Disease Control. The overall varicella incidence was calculated and associated with temperature, overcrowding, age, gender and population density.

RESULTS

The epidemiology of varicella showed an intriguing pattern, in which warmer regions were characterized by higher incidences than in temperate regions. Young children were the most affected age group. There was no correlation between varicella incidence and overcrowding or population density.

CONCLUSIONS

The epidemiology of varicella in Mexico significantly departs from the characteristic patterns observed in other tropical latitudes, with some features resembling those commonly associated with temperate regions.