Prevalence of Intestinal Parasitoses in Dogs within a Vulnerable Area of Ensenada, Buenos Aires Province, Argentina

Research Article

Austin J Infect Dis. 2023; 10(4): 1093.

Prevalence of Intestinal Parasitoses in Dogs within a Vulnerable Area of Ensenada, Buenos Aires Province, Argentina

María Iné1 Gamboa1,2*; Marcos J Butti1; Valeria VCorbalán1; Beatriz A Osen1; Antonela Paladini1; Estela B Bonzo3; Fiamma Lagala1; Nilda E Radman1

¹Cátedra de Parasitología Comparada-Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Argentina

²Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC), Argentina

³Cátedra de Higiene, Epidemiologia y Salud Pública, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Argentina

*Corresponding author: María Inés Gamboa Cátedra de Parasitología Comparada-Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Calle 60 y 118 (1900) La Plata, Buenos Aires, Argentina Tel: +54-221-4236663 int 413 Email: minesgamboa@fcv.unlp.edu.ar

Received: September 09, 2023 Accepted: November 20, 2023 Published: November 27, 2023

Abstract

The potential role of dogs as reservoirs of zoonotic infections is one of the major public health problems. Water emergency areas are generally vulnerable zones with a lack of care from the owners who do not have the basic sanitary service conditions. Dogs often feed on waste detecting coprophagia of human faeces facilitated by the fi nal disposal of excreta in open-air defecation. The objective of this research was to determine the presence of intestinal parasitoses in dogs from a sanitary risk area inhabited by a vulnerable human population. Dog faeces were collected by an enema with a soapy solution and processed by the Telemann’s sedimentation technique as well as the Sheather’s flotation procedure besides a direct examination. A number of 703 (79.3%) analyzed dog faeces were parasitized from a total of 886. Ancylostoma caninum (57%), Toxocara canis (24%) and Uncinaria stenocephala (21%) were the most frequent species. The specifi c richness in the dog population was 17 species. The highest parasitosis frequency was observed among male dogs and those under one-year aged for the total parasitized ones with T. canis, Cystoisospora canis, C. ohioensis, and Giardia spp. High prevalences found in dogs from the present study could indicate that both diagnosis and treatment are not enough to achieve sustainable changes in vulnerable areas. Actions addressed to the environmental factor are essentials in order to avoid reinfections.

Keywords: Dogs; Intestinal parasitoses; Prevalence; Vulnerable population; Zoonoses

Impacts

• It was used 3 different techniques of detection of enteroparasitosis.

• It was detected high prevalence of canine enteroparasitosis (79.3%). Ancylostoma caninum, Toxocara canis and Uncinaria stenocephala were the most frequent species.

It was detected several zoonotic species. The highest frequency of parasitosis has been observed among male and under 1 year of age.

Introduction

Intestinal parasitoses show a high prevalence in dogs despite the empirical use of antiparasitic drugs and several control measures recommended by veterinarians. The potential role of dogs as reservoirs of zoonotic infections is one of the major public health problems. Water emergency areas are generally those where the population has unsatisfi ed basic needs [44], a vulnerability accompanied by low purchasing power. These are usually suburban areas with several animals per family. Dogs are careless, wanderers, underfed or malnourished, with the potential of consuming rats, waste, and sometimes human or other animal faeces as a product of the prevailing structural shortage [57]. Vulnerable zones are made up of informal dense urbanizations with precarious housing without access to suitable sanitary facilities occupied by populations of a low socioeconomic and educational level [1]. The lack of pet care by the owners is common in these populations. Dogs usually feed on waste and often perform coprophagy of human faeces facilitated by the fi nal disposal of excrements at open-air defecation. Coexistence with domestic animals favors the presence and maintenance of infections, reinfections, and coinfections in these areas [22]. The problem is worsening by the movement of cysts, oocysts, eggs, and larvae until they are spread by rainwater or fl ooding. This is in addition to the presence of ditches where animals usually drink, feed on fi sh, toads, and frogs, paratenic hosts of parasitosis, and where excrements and wastewater from dwellings are disposed of [54]. The water quality for domestic use is generally inadequate with clandestine connections and the river water use for drinking, food production, and recreational activities hold a signifi cant impact on human and animal health [38]. Canines can disseminate transmissible intestinal parasitoses to humans with their faeces [14]. Some helminthiases [27,65], several protozoonoses [68,72], and the parasitic algae Blastocystis spp. [48], are common fi ndings on dogs and humans. Animal intestinal parasite nematodes of the genus Toxocara spp. Cause toxocarosis in humans, a disease of high seroprevalence in La Plata city [52], other regions of America [31], and the rest of the world [12,28,61].

Its neurological and ocular parasitic forms usually have serious consequences. Its presence in humans is favorably infl uenced by the residence place in suburban area [5,13,53]. The zoonotic enteroparasite Giardia spp. [39] causes acute or chronic diarrhea, and changes in the microbiome of canines, an effect still poorly studied [7]. Antiparasitic drugs reduce environmental contamination by parasitic dissemination forms and they are effective in their control. However, it is difficult to use all available information to evaluate the true drug efficacy such as the understanding of either possible geographic variations or drug resistance [40], among other variables. Sentinel animals can be used for surveillance of pathogen circulation. In this sense, dogs can act as bioindicators providing early evidence of emerging zoonotic diseases circulating in a certain area or region [8,24,63].

In Argentina, there is not enough information on intestinal parasitoses prevalence in dogs since most surveys were based on fecal samples collected from the ground [15,34,59,64].

The district of Ensenada, Buenos Aires Province, is composed of 14,660 households of which 10.3% have their basic needs unsatisfi ed [44]. The El Molino neighborhood is located right there, inhabited by a vulnerable population on the coast of the Río La Plata, a water emergency area. Its current layout is the result of an uninterrupted occupation process being the area a settlement area for people coming from other Argentinian provinces and neighboring countries without resources. This, together with the lack of infrastructure works and increasing deforestation increases its vulnerability.

Studies on canine intestinal parasitoses from this site report 92% [18], and 76.7% [54]. Special characteristics determined that this was selected as a sentinel area. Sentinel Sites located in areas of vulnerability are considered remote sensors that send alarm signals of selected variables. The variability effect on the stability of the population's livelihoods is refl ected in higher levels of chronic and acute malnutrition, and other diseases, especially the transmissible ones. Sentinel surveillance allows the decision-maker to establish previsions and respond to emergencies in due time.

The objective of this work was to determine the presence of canine intestinal parasitoses in a health-risk area inhabited by a vulnerable population.

Materials and Methods

Study Area

The El Molino neighborhood (34° 55’ S, 57° 56’ W) within the Marginal Forest of Punta Lara, the southernmost gallery forest in the world, has specifi c hydrographic characteristics that contribute to the spread of parasites [9]. Floodings are not caused by rain but rather by southeast winds from the La Plata River which overcomes the estuary containment for its fl at shores. These geomorphological features combined with a lack of river containment, channeling infrastructure, and an increase in the local resident population, raise the vulnerability of the area and favor the development of parasites. In addition, a clay-enhanced soil avoids the rainwater absorption also overlapping some cyclical fl ooding (Figure 1).

The dominant weather belongs to a plain wet-temperate type with mid-temperature conditions and mid-high rainfalls distributed regularly throughout the year. The relative moisture is high and the water balance shows a remarkable predominance of water surpluses over water defi cits.

Regular rainy periods extend from October to April. Rainfalls slightly exceed 1000 mm per year. The lowest rainfalls are recorded during winter although there is a non-defi ned dry season. The mean annual temperature is 16°C with mild winters and hot summers. Extreme temperatures are between 42°C and -4°C being January the warmest month with a mean of 22.5°C and July the coldest with a mean of 9.7°C.

Sampling

Sampling occurred within a framework of monthly educational healthcare workshops that took place from 2015 to 2019 at the “El Molino” neighborhood. Animals were spontaneously taken by their owners to be vaccinated, and they all provided several samples for diagnosis.

Socio-Environmental Data

Epidemiological data related to dogs were collected by specially designed forms in which all information concerning owner and animal backgrounds was recorded such as canine age, eating habits, and mobility within the neighborhood.

The delivery material included a consent-informed form allowing permission for interventions of clinical examination and sampling, vaccination (Rabies vaccine), and treatment, if relevant.

Dog Samples

Animals brought voluntarily by their owners were vaccinated and examined by echography at the same time as they provided samples for diagnosis. Dog faeces were collected by a soapy solution enema and processed by both the Telemann´s sedimentation technique and Sheather’s flotation besides a direct examination. Dissemination elements (eggs, larvae, cysts, and oocysts) were identifi ed according to their morphology [60]. This study received approval from the Ethical Committee of the School of Veterinary Medicine at the National University of La Plata.

Results

From the 886 analyzed canine faeces, 703 (79.3%) were parasitized being Ancylostoma caninum, Toxocara canis and Uncinaria stenocephala the most frequent species (Table 1). The specifi c richness of the dog population was 17 species. A higher parasitosis frequency was observed in male canines (82.8%) than in females (75.4%), with signifi cant differences (X2 correct Yates= 6.9 p<0.01). The statistical association between both sex and parasite prevalence was only maintained in A. caninum (X2 correct Yates=19, p<0.01), the most frequent species, analyzing this variable by each species. There was an association with dog ages being those under one-year aged -up to 1 year old- the most parasitized compared to those over one-year aged (X2= 7.9 p<0.01). Signifi cant differences were found with higher prevalence among the under one-year aged canines than the older ones for T. canis (X2=50.1, p<0.01), OR: 3.524 (95% CI 2.4-5.0) pointing out they are 3.5 times more likely to host T. canis than those older ones analyzing the age distribution for each species. The same occurred with Giardia spp. (X2=5.9, p=0.01), Cystoisospora ohioensis (X2=7.2, p<0.01), and C. canis (X2=11.5, p<0.01), OR: 4.4 (95%CI 1.5-12) indicating that under one-year aged dogs are 4.4 times more likely to host C. canis than older ones (Table 1). However, the association was inverse for T. vulpis (X2=15.7, p<0.01), OR: 0.476 (95%CI 0.333-0.681), that is to say, juveniles are 2.1 less likely to have T. vulpis than older ones. In the case of Capillaria spp. (X2=10.8, p<0.01), OR: 0.278 (0.129-0.602), under or equal one-year aged canines have 3.6 fewer chances to host Capillaria spp. than older ones.

Citation: Gamboa MI, Butti MJ, Corbalán VV, Osen BA, Paladini A, et al. Prevalence of Intestinal Parasitoses in Dogs within a Vulnerable Area of Ensenada, Buenos Aires Province, Argentina. Austin J Infect Dis. 2023; 10(4): 1093.