Ecology and geography of hemorrhagic fever with renal syndrome in Changsha, China

Abstract

BackgroundHemorrhagic fever with renal syndrome (HFRS) is an important public health problem in mainland China. HFRS is particularly endemic in Changsha, the capital city of Hunan Province, with one of the highest incidences in China. The occurrence of HFRS is influenced by environmental factors. However, few studies have examined the relationship between environmental variation (such as land use changes and climate variations), rodents and HFRS occurrence. The purpose of this study is to predict the distribution of HFRS and identify the risk factors and relationship between HFRS occurrence and rodent hosts, combining ecological modeling with the Markov chain Monte Carlo approach.MethodsEcological niche models (ENMs) were used to evaluate potential geographic distributions of rodent species by reconstructing details of their ecological niches in ecological dimensions, and projecting the results onto geography. The Genetic Algorithm for Rule-set Production was used to produce ENMs. Data were collected on HFRS cases in Changsha from 2005 to 2009, as well as national land survey data, surveillance data of rodents, meteorological data and normalized difference vegetation index (NDVI).ResultsThe highest occurrence of HFRS was in districts with strong temperature seasonality, where elevation is below 200 m, mean annual temperature is around 17.5°C, and annual precipitation is below 1600 mm. Cultivated and urban lands in particular are associated with HFRS occurrence. Monthly NDVI values of areas predicted present is lower than areas predicted absent, with high seasonal variation. The number of HFRS cases was correlated with rodent density, and the incidence of HFRS cases in urban and forest areas was mainly associated with the density of Rattus norvegicus and Apodemus agrarius, respectively.ConclusionsHeterogeneity between different areas shows that HFRS occurrence is affected by the intensity of human activity, climate conditions, and landscape elements. Rodent density and species composition have significant impacts on the number of HFRS cases and their distribution.

A Space-Time Study of Hemorrhagic Fever with Renal Syndrome (HFRS) and Its Climatic Associations in Heilongjiang Province, China

“…To the best of our knowledge, very few studies have used analytical methods to describe the space-time HFRS spread in Heilongjiang province. On the other hand, the associations between HFRS incidence and climate factors have been always assessed in terms of numerical modeling, for example, autoregressive integrated moving average models (ARIMA), seasonal ARIMA (SARIMA), ecological niche models (ENM), Poisson regression models, multiple regression, conditional logistic regression, and principal components regression (PCR) models [25,34,[45][46][47][48]. Interestingly, none of these studies explored the association between HFRS incidence and climatic factors in the context of their co-variation.…”

Transmission of Haemorrhagic Fever with Renal Syndrome in China and the Role of Climate Factors: A Review

“…1 Symptoms include fever, headache, back pain, abdominal pain, hypotension, multisystemic haemorrhage and acute renal failure. [2][3][4] The five clinical stages of HFRS are: febrile, hypotensive, oliguric, diuretic, and convalescent.…”

Effects of Humidity Variation on the Hantavirus Infection and Hemorrhagic Fever with Renal Syndrome Occurrence in Subtropical China

“…31 And the intensive human activities provide suitable living conditions for rodents, as well as the transmission of HV. 32 Infection risks in districts where TVDI is between 0.25 and 0.5 (P = 0.98) may result from concentrated sampling sites. The likely reasons for high infection risks in areas with low elevation may possibly reflect the geographical conditions and land use types in these regions.…”

“…Cultivated and building lands, which are suitable for the existence and distribution of rodents, are widely distributed in areas with low elevation. 32,33 The cultivated land environment of most villages in China is suitable for rodent survival and development, and high rodent densities persist in many fields and villages. 34 The relatively high population density that focused on the building land also increases rates of contacts between rodents and humans.…”