Seasonality and meteorological factors of HIV-negative cryptococcal meningitis in Guangdong Province, China

Abstract

Objective: Information about the seasonal characteristics of human immunodeficiency virus (HIV)-negative cryptococcal meningitis (CM) is quite limited. The aim of this study was to explore the seasonality and meteorological factors of HIV-negative patients with CM.

Methods: We performed a retrospective study of 469 HIV-negative CM patients admitted to the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong Province, China. Their initial onset symptoms of CM occurred from January 2011 to December 2020. The temperature, precipitation, sunlight, humidity and wind speed for the corresponding period and the associated topographic, ecological type and soil type parameters data were collected. The Poisson regression model was used to determine the meteorological factors associated with CM onset. The geographical detector method was used to detect other environmental factors associated with CM onset.

Results: CM onset did not showed a seasonal fluctuation, but was strongly associated with mean temperature (β = .010, p = .028) and mean relative humidity (β = -.011, p = .006). In the rainy season, only mean wind speed remained significantly associated with CM onset (β = -.108, p = .041). In the dry season, mean temperature (β = .014, p = .016), mean relative humidity (β = -.016, p = .006) and hours of sunlight (β = -.002, p = .016) were significantly associated with CM onset. Topographic, ecological type and soil type factors did not add explanatory power.

Conclusions: Our findings add the knowledge about the environmental factors of HIV-negative CM. Meteorological factors, especially temperature and humidity, may be the main environmental factors affecting the onset of HIV-negative CM.

Keywords: HIV-negative; cryptococcal meningitis; humidity; meteorological factors; seasonality; temperature.