Trends of the global, regional and national incidence of malaria in 204 countries from 1990 to 2019 and implications for malaria prevention

Abstract

Background Malaria is a life-threatening disease worldwide, but lacks studies on its incidence at the global level. We aimed to describe global trends and regional diversities in incidence of malaria infection, to make global tailored implications for malaria prevention. Methods We used the data from the Global Burden of Disease Study 2019. The age-standardized incidence rate (ASR) and absolute number of malaria episodes showed the epidemic status of malaria infection. The estimated annual percentage change (EAPC) of ASR and changes in malaria episodes quantified the malaria incidence trends. The connection between ASRs and traveler number indicated infection risk for travelers. Results Globally, the malaria ASR decreased by an average 0.80% (95%CI 0.58%–1.02%) per year from 1990 to 2019; however, it slightly increased from 3195.32 per 100 000 in 2015 to 3247.02 per 100 000 in 2019. The incidence rate of children under 5 was higher than other age groups. 40 countries had higher ASRs in 2019 than in 2015, with the largest expansion in Cabo Verde (from 2.02 per 100 000 to 597.00 per 100 000). After 2015, the ASRs in high-middle, middle and low-middle SDI (the Socio-demographic Index) regions began to rise, and the uptrends remained in 2019. Central, Western and Eastern Sub-Saharan Africa had the highest ASRs since 1990, and traveler number in Eastern and Western sub-Saharan Africa increased by 31.24% and 7.58%, respectively from 2017 to 2018. Especially, most countries with ASR over 10 000 per 100 000 had increase in traveler number from 2017 to 2018, with the highest change by 89.56% in Mozambique. Conclusions Malaria is still a public health threat for locals and travelers in sub-Sharan Africa and other malaria-endemic areas, especially for children under 5. There were unexpected global uptrends of malaria ASRs from 2015 to 2019. More studies are needed to achieve the goal of malaria elimination.

Hepatitis B virus infection among 90 million pregnant women in 2853 Chinese counties, 2015-2020: a national observational study

“…Most previous studies reported province or regional prevalence of HBV infection in China, such as Tianjin (3.8%) [29] , Zhejiang (5.9%) [30] and Taiwan (12.4%) [31] . At national level, there were four national epidemiological surveys on investigating HBV infection in the general population in China, which was conducted in 1979 [22] , 1992 (including people aged 1-59 years) [32] , 2006 (including people aged 1-59 years) [ 33 , 34 ], and 2014 (including people aged 1-29 years) [9] , respectively. After 2006, there were no national representative survey conducted in the general population aged 1-59 years, especially for adults.…”

“…We calculated the estimated annual percentage change (EAPC), a summary and widely used indicator to show the trend and annual change over a specified time interval [ 21 , 22 ]. There are many methods to estimate the annual percentage change [23] , [24] , [25] , [26] , [27] .…”

“…There are many methods to estimate the annual percentage change [23] , [24] , [25] , [26] , [27] . We chose a most used methods in the field of infectious disease and maternal health [ 21 , 22 , 28 ] to make it comparable to previous studies. A regression line was fitted to the natural logarithm of HBV prevalence using the formula y = α + βx +ε, where y refers to ln (HBV prevalence) and x refers to calendar year.…”

“…A regression line was fitted to the natural logarithm of HBV prevalence using the formula y = α + βx +ε, where y refers to ln (HBV prevalence) and x refers to calendar year. EAPC was calculated as 100 × (e β - 1) and its 95% confidence intervals (CIs) was also calculated to assess the temporal trend of the prevalence [ 21 , 22 ]. If the EAPC estimation and its 95% CIs were both <0 (or both >0), HBV prevalence was deemed to be in a decreasing trend (or an increasing trend) in the given time interval [ 21 , 22 ].…”

“…EAPC was calculated as 100 × (e β - 1) and its 95% confidence intervals (CIs) was also calculated to assess the temporal trend of the prevalence [ 21 , 22 ]. If the EAPC estimation and its 95% CIs were both <0 (or both >0), HBV prevalence was deemed to be in a decreasing trend (or an increasing trend) in the given time interval [ 21 , 22 ]. In this study, we considered two-sided p values of lower than 0.05 to be statistical significance.…”