Effect of climate factors on the incidence of hand, foot, and mouth disease in Malaysia: A generalized additive mixed model

Abstract

Climate change is one of the critical determinants affecting life cycles and transmission of most infectious agents, including malaria, cholera, dengue fever, hand, foot, and mouth disease (HFMD), and the recent Corona-virus pandemic. HFMD has been associated with a growing number of outbreaks resulting in fatal complications since the late 1990s. The outbreaks may result from a combination of rapid population growth, climate change, socioeconomic changes, and other lifestyle changes. However, the modeling of climate variability and HFMD remains unclear, particularly in statistical theory development. The statistical relationship between HFMD and climate factors has been widely studied using generalized linear and additive modeling. When dealing with time-series data with clustered variables such as HFMD with clustered states, the independence principle of both modeling approaches may be violated. Thus, a Generalized Additive Mixed Model (GAMM) is used to investigate the relationship between HFMD and climate factors in Malaysia. The model is improved by using a first-order autoregressive term and treating all Malaysian states as a random effect. This method is preferred as it allows states to be modeled as random effects and accounts for time series data autocorrelation. The findings indicate that climate variables such as rainfall and wind speed affect HFMD cases in Malaysia. The risk of HFMD increased in the subsequent two weeks with rainfall below 60 mm and decreased with rainfall exceeding 60 mm. Besides, a two-week lag in wind speeds between 2 and 5 m/s reduced HFMD's chances. The results also show that HFMD cases rose in Malaysia during the inter-monsoon and southwest monsoon seasons but fell during the northeast monsoon. The study's outcomes can be used by public health officials and the general public to raise awareness, and thus, implement effective preventive measures.

The impact of anti‐COVID‐19 nonpharmaceutical interventions on hand, foot, and mouth disease—A spatiotemporal perspective in Xi'an, northwestern China

“…8,9 Surprisingly, studies revealed that not only respiratory infectious diseases but also intestinal infectious diseases cases dramatically decreased in multiple regions during the COVID-19 pandemic. [10][11][12] This indicated that the positive effects of anti-COVID-19 measures extended to several other communicable diseases, [13][14][15] and were also confirmed in China. 16 Specifically, there was a more dramatic decline in HFMD incidence than in other intestinal infectious diseases in 2020.…”

“…To overcome the COVID‐19 crisis, governments worldwide implemented a series of corresponding measures using nonpharmaceutical interventions (NPIs) (e.g., home quarantine, reducing social distancing, travel restrictions, and masking), which have mitigated the magnitude and geographical scope of COVID‐19 propagation 8,9 . Surprisingly, studies revealed that not only respiratory infectious diseases but also intestinal infectious diseases cases dramatically decreased in multiple regions during the COVID‐19 pandemic 10–12 . This indicated that the positive effects of anti‐COVID‐19 measures extended to several other communicable diseases, 13–15 and were also confirmed in China 16 .…”

Investigation of the Correlation between Enterovirus Infection and the Climate Factor Complex Including the Ping-Year Factor and El Niño-Southern Oscillation in Taiwan

“…Previous studies have found a correlation between climate factors and the prevalence of enterovirus infections, with several climate factors, including temperature, humidity, rainfall, wind speed, sunshine, and air pressure, being identified as important factors. For example, temperature has been widely recognized as one of the most important climate factors that affect the prevalence of enterovirus infection [ 8 , 9 , 10 , 11 ]. One study found a positive correlation between the incidence of hand, foot, and mouth disease (HFMD) and a 1 °C increase in temperature [ 8 ], while other studies showed that temperature has a delayed impact on enterovirus prevalence ranging from several days to weeks [ 9 , 10 , 12 ].…”

“…For example, temperature has been widely recognized as one of the most important climate factors that affect the prevalence of enterovirus infection [ 8 , 9 , 10 , 11 ]. One study found a positive correlation between the incidence of hand, foot, and mouth disease (HFMD) and a 1 °C increase in temperature [ 8 ], while other studies showed that temperature has a delayed impact on enterovirus prevalence ranging from several days to weeks [ 9 , 10 , 12 ]. However, some studies have found a nonlinear inverted V-shaped relationship between HFMD and temperature [ 13 ], while others have found no statistically significant correlation [ 14 , 15 ].…”

“…However, some studies have found a nonlinear inverted V-shaped relationship between HFMD and temperature [ 13 ], while others have found no statistically significant correlation [ 14 , 15 ]. These studies were conducted in different Asian countries [ 9 , 10 , 16 , 17 ]. Considering the varying climate conditions across different regions, it is not appropriate to rely on a single climate factor.…”