A neglected zoonotic disease (NZD)could be defined as a disease transmitted from animals to humans,commonly associated with poverty thatimpacts the lives and livelihoods of neglected populations. The socioeconomic impacts of NZDs are expanding in the developing world, there is a major burden for poor rural communities¹. Balantidiasisis not listed among the well-known NZDs, however, it shows all the key characteristics of NZDs.In fact, Balantidium coli,the etiological agent of balantidiasis,the sole ciliated protozoan that affect the gastrointestinal tract of humans, is transmitted by fecal-oral route in which contaminated drinking water or food are the mainroute of transmission. In balantidiasis exists a kind of “liar paradox”, in fact, on one hand, based on the literature,B. coli could not be considered a public health problem because infections are usually asymptomatic and in humans, the overall prevalence is estimated to be 0.02 to 1%^2,3,4.On the other hand,some authors report that the parasite could invade the intestinal wall causing diarrhea, abdominal pain, nausea, vomiting, and in severe cases the death of the host ⁵; with an overall prevalence in endemic areas that reaches 30%^6,7. What is the truth? The truth is that this parasitosis, due to the low pathogenic relevance, is often underestimated, both in human and animal populations.Considering the high prevalence in livestock and the pathogenic potential of this disease, it is mandatory to predict the appearance of new balantidiasis outbreak, especially in the poor rural scenario.Remarkably, the outbreaks of balantidiasis are strongly related to its presence in animals hosts, being particularly exposed to people working with animals (i.e., veterinary, farmer and slaughterhouse worker), especially those in contact with pigs that,together with rodents, are the main reservoir of the disease ^2,8.Worldwide,the B. coli prevalence in domestic pigs ranges from 50 to 100% and the breeding system and related management practices are the main factors influencing the infection rates ^4,9,10,11. In livestock, sanitation management of environment and animals ensure effective control of parasitic infection ⁹.

In developing countries, this parasitosis could be a serious threat and its spread is related to the contamination of water and food sources with swine faeces, while in developed countries recreational water represents a further source of infection (i.e., in swimming pools, human-to-human transmission)¹².

The presence of B. colicysts, revealed in faeces of slaughtered animals, raises concerns for food safety and public health due to the possible contamination of the car casses ¹³. During slaughtering, since B. coli inhabits the last intestinal tracts of animals, inadequate evisceration could determine meat contamination as well as poor hygiene practices could lead to cross-contamination among the carcasses.Under certain favourable conditions (i.e., cold chain failure), B. colicysts could persist on the carcass surface along with the production chain exposing humans to infection by consumption of raw or under cooked meat and meat products ¹⁴

Furthermore, more attention should be paid to the hygiene condition during the domestic slaughtering of pigs frequently practiced in both developing and developed countries.

Overall,good manufacturing and hygiene practices would ensure effective management of B. coli risk along with the production chain, as well as the cooking of meat in the households.

Nowadays, despite the high prevalence reported in farmed animals and its zoonotic relevance, only a few and dated studies investigated the occurrence of B.coli in foods which may represent a new and important transmission pathway, especially in the developed countries.Considering that the pathogenic relevance (i.e., from asymptomatic to severe clinical disease)of B. coli infection in humans is still poorly understood, it is mandatory to monitor the presence of this parasitosis and to update the information on B. coli prevalence in farm animals in both developed and developing countries.

Reference

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