Introduction
Angiostrongylus cantonensis (the rat lungworm), the primary
causative agent for several outbreaks of eosinophilic meningitis in
humans (Tseng et al., 2011), was first described by Chen (1935) based on
the worms collected from the pulmonary arteries of infected rats in
Guangzhou, China. The first human infection by this nematode was
reported in Taiwan, by Nomura and Lin, 10 years later (Beaver and Rosen,
1964). Angiostrongylus cantonensis infection typically presents
as eosinophilic meningitis; however, other manifestations in the form of
ocular angiostrongyliasis, encephalitis, and radiculomyelitis have also
been reported. Primary symptoms include acute headaches, eosinophilia in
the blood and cerebrospinal fluid (CSF), and other symptoms ranging from
fever, hyperesthesia, paresthesia, nausea, vomiting and in some rare
cases even coma and death (Cowie et al., 2022). There is an additional
risk of developing chronic sequelae, which is majorly debilitating.
Definitive diagnosis of this infection has proved to be challenging;
given visual detection of parasite in patient samples is rare; and the
amplification of the ITS1 region of the parasite DNA from the patient’s
CSF has a detection rate of merely 65.3% (Jarvi et al., 2023). Hence,
spreading awareness for prevention is just as important as finding a
cure.
Angiostrongylus cantonensis nematode is a parasite, its
synanthropic definitive and intermediate hosts being rodents
(particularly Rattus spp.) and a diverse range of gastropods,
respectively; however, animals such as shrimp, frogs, and lizards can
act as paratenic hosts (Turck et al., 2022) (Figure 1). Consumption of
such hosts have given rise to further cases and outbreaks ofAngiostrongylus cantonensis infection in humans in several
countries, including Taiwan (Tseng et al., 2011), Thailand (Eamsobhana,
2014), China (Lv et al., 2009), Brazil (Morassutti et al., 2014), USA
(Cowie et al., 2017), Vietnam (McBride et al., 2017), Australia (Barratt
et al., 2016), and India (Pandian et al., 2023). A number of cases have
occurred in travelers to endemic areas, where consumption of exotic
dishes and contaminated foodstuffs result in infection (Federspiel et
al., 2020), which highlights the necessity for further awareness about
this disease and its causative agent. Indeed, there are concerns as to
the extent of infection the rat lungworm can inflict upon humans, where
cases have shown presence of the parasite in the lungs of human patients
(Prociv et al., 2000). Nevertheless, as the presence ofAngiostrongylus cantonensis in human feces have not yet been
identified, hence the spread of Angiostrongylus cantonensisdepends largely on its natural hosts; rats and gastropods.