Global prevalence of Ascaris infection in humans (2010–2021): a systematic review and meta-analysis

Abstract

Background Ascariasis is one of the most important neglected tropical diseases of humans worldwide. The epidemiology of Ascaris infection appears to have changed with improvements in sanitation and mass drug administration, but there is no recent information on prevalence worldwide. Here, we performed a systematic review and meta-analysis to assess the global prevalence of human Ascaris infection from 2010 to 2021. Methods We searched MEDLINE/PubMed, and Scopus databases for studies measuring prevalence of Ascaris infection, published between 1 January 2010 and 1 January 2022. We included studies of the general human population in endemic regions, which used accepted coprodiagnostic methods, and excluded studies of people with occupations with an increased risk or probability of ascariasis and/or specific diseases other than ascariasis. We applied random-effects models to obtain pooled prevalence estimates for six sustainable development goal regions of the world. We extrapolated the prevalence estimates to the global population in 2020, to estimate the number of individuals with Ascaris infection. We conducted multiple subgroup and meta-regression analyses to explore possible sources of heterogeneity, and to assess relationships between prevalence estimates and demographic, socio-economic, geo-climatic factors. Results Of 11,245 studies screened, we analysed 758 prevalence estimates for a total number of 4,923,876 participants in 616 studies from 81 countries. The global prevalence estimated was 11.01% (95% confidence interval: 10.27–11.78%), with regional prevalences ranging from 28.77% (7.07–57.66%) in Melanesia (Oceania) to 1.39% (1.07–1.74%) in Eastern Asia. We estimated that ~ 732 (682–782) million people harboured Ascaris worldwide in 2021. The infected people in Latin America and the Caribbean region had a higher prevalence of high intensity infection (8.4%, 3.9–14.1%). Prevalence estimates were higher in children, and people in rural communities or in countries or regions with lower income and human development indices. There was a trend for a higher prevalence in regions with increasing mean annual relative humidity, precipitation and environmental temperature. Conclusions Our findings indicate that, despite a renewed commitment by some communities or authorities to control ascariasis, a substantial portion of the world’s human population (> 0.7 billion) is infected with Ascaris. Despite the clinical and socioeconomic importance of ascariasis, many past routine surveys did not assess the intensity of Ascaris infection in people. We propose that the present findings might stimulate the development of customised strategies for the improved control and prevention of Ascaris infection worldwide.

Influence of tides on the dissemination and related health risks of intestinal helminths along the Kribi beaches (Atlantic Coast, Southern Cameroon)

“…At the beginning, the disease is manifested by respiratory disorders with fever at 38°C, dry cough, sometimes productive coughing, and breathing difficulties. Later on, digestive disorders, nausea, vomiting, abdominal pain, loss of appetite, and diarrhoea can emerge (Silver et al 2018; Holland et al 2022). A. duodenale is a nematode, responsible for hookworm disease or Ankylostomiasis.…”

Gastrointestinal parasitosis diagnosed by colonoscopy as cause of weight loss in 46-year-old woman with three negative stool tests for presence of parasites

“…The results of epidemiological studies show that intestinal parasitosis continues to be a serious problem in the world. According to the results of a systematic review and meta-analysis by Holland et al [7], in 2021 around 732 million people were infected with Ascaris roundworms worldwide. The incidence of this infection was estimated at 11.01% (95% confidence interval: 10.27-11.78%) and it varied geographically, ranging from 28.77% in Melanesia (Oceania) to 1.39% (1.07--1.74%) in Eastern Asia.…”

Programmed DNA elimination in the parasitic nematode Ascaris

“…For simplicity, we use Ascaris to refer to both species in this review. Ascaris was estimated to infect >700 million people worldwide in 2021 [ 7 ]. Most cases are found in impoverished children [ 8 – 10 ].…”