China’s history with A. cantonensis serves as a powerful microcosm of the global challenge posed by this emerging zoonosis. The country’s experience, marked by initial cases, devastating outbreaks, and the development of a robust national response, offers invaluable lessons for other nations facing similar threats.
The first confirmed human case of angiostrongyliasis in Chinese mainland was documented in 1984 [13]. A 13-year-old boy from Xuwen, Guangdong Province, presented with symptoms of meningitis. A critical epidemiological link was established: the boy frequently helped his family feed ducks by crushing Achatina fulica snails. Examination of his cerebrospinal fluid (CSF) revealed the presence of A. cantonensis larvae, confirming the diagnosis. Fortunately, the boy made a full recovery. This case was a watershed moment, demonstrating that the parasite was not just a theoretical risk but an active public health issue in China.
The first fatal case, reported in 1995 from Guangzhou, underscored the potential severity of the disease. An 11-month-old infant from a poor residential area died from the infection. Post-mortem examination revealed hundreds of adult worms in her pulmonary arteries, and infected A. fulica snails were found in the vicinity of her home[14]. This tragic case highlighted the vulnerability of children and the role of poor sanitation and environmental contamination in the disease transmission.
The first major outbreak occurred in 1997 in Wenzhou, Zhejiang Province, a region north of the traditional endemic zones in southern China. A total of 182 clients at a single restaurant were at risk. Of the 105 individuals who consumed a raw snail dish, 47 were diagnosed with angiostrongyliasis [15]. Crucially, none of the 77 clients who ate only cooked snails developed symptoms, providing strong evidence for the transmission route. A clear dose–response relationship was observed: the incidence was 86.2% among those who ate more than four pieces of snail, compared to 28.9% among those who ate less. Investigation confirmed the presence of the parasite in both the restaurant’s Pomacea spp. snails and local rats [16]. This outbreak was a wake-up call, demonstrating the potential for large-scale foodborne transmission and the parasite’s ability to spread to new regions within the country.
The largest outbreak to date in China occurred in Beijing, the capital, in 2006. Between June and August, 160 cases were registered, with 100 requiring hospitalizations. This outbreak was particularly significant because Beijing is not a traditional endemic area due to lack of Pomacea spp. snail habitats. Nearly all hospitalized patients confirmed consuming snail dishes at two branches of the same restaurant. Again, the investigation traced the source to infected Pomacea spp. snails imported from southern China [17]. This event, occurring in the capital city of the country, triggered a massive public health response and became the catalyst for a comprehensive national program to combat angiostrongyliasis, one of the food-borne infectious diseases.
The launch of the national program in 2006 marked a turning point, with the following key initiatives:
First national survey (2006–2007): A systematic investigation on the distribution of A. cantonensis and its rodent and mollusk hosts across China [10].
Standardized diagnosis (2010): The Ministry of Health released official diagnostic criteria for angiostrongyliasis, ensuring uniformity in case detection and reporting.
Routine surveillance (2009–present): A national surveillance and reporting system was established to monitor human cases and snails in markets, in some areas, environmental contamination.
Capacity building: Ongoing efforts to train healthcare professionals in diagnosis and management and to strengthen laboratory and research capabilities related to control and prevention of angiostrongyliasis.