Efficacy of monthly treatment with oral fluralaner (Bravecto® 1-Month) against Tunga penetrans in dogs in Brazil: a randomized, double-blind, controlled field study.

BACKGROUND: Tungiasis is a neglected tropical disease caused by the adult female sand flea (Tunga penetrans). Dogs are considered important reservoirs of T. penetrans in Brazil. The aim of this study was to determine the monthly insecticidal efficacy of a single oral administration of fluralaner at a dose of 10-18 mg/kg (Bravecto® 1-Month, also registered as Defenza® in some countries; MSD Animal Health) in dogs naturally infested with T. penetrans. METHODS: This clinical trial was conducted in a rural community located in Ilhéus, Bahia, Brazil. A total of 64 dogs were selected and distributed in a completely randomized design between a treated group (TG) that received one single dose of Bravecto® 1-Month (Defenza®) and a negative control group (CG) that received no treatment. Each group was composed of 32 dogs. The evaluations took place on days 0, 7 ± 2, 14 ± 2, 21 ± 2, 28 ± 2, 35 ± 2, and 42 ± 2 post treatment, in which the dogs were inspected to evaluate the infestation stage and classify lesions associated with tungiasis. The primary efficacy was determined from the percentage of treated dogs free of fleas (stage II and III lesions) after administration of the formulation at each evaluation time. Secondary efficacy was based on the number of active lesions (stages II and III) in each group at each evaluation time. The clinical condition of the animals was defined based on the Severity Score for Acute Dog Tungiasis (SCADT), which is related to the number and severity of lesions. RESULTS: The primary efficacy of the product was greater than 95.0% from days 7 to 21 and reached 100.0% between days 28 and 42, with a significant association between treatment and infestation decline (P < 0.025) between days 7 and 42. Secondary drug efficacy was greater than 99.9% from days 7 to 21, reaching 100.0% between days 28 and 42 (P < 0.05). The treated dogs also scored lower on the SCADT than the control animals did during the entire clinical evaluation period (P < 0.05). CONCLUSIONS: A single administration of Bravecto® 1-Month (Defenza®) was effective in eliminating Tunga penetrans infestations, as well as in preventing parasitism for at least 42 days after treatment.

Efficacy of an oral formulation of afoxolaner and milbemycin oxime against Tunga penetrans in naturally infected dogs.

BACKGROUND: The sand flea Tunga penetrans is one of the agents of tungiasis, an important parasitic skin disease affecting humans and several mammalian species. Tungiasis is mainly observed in disadvantaged rural and peripheral urban communities in Latin America and sub-Saharan Africa. The dog is a major reservoir of Tunga fleas. Hematophagous adult female Tunga spp. embed and grow in their host's epidermis and cause cutaneous inflammatory disorders. NexGard Spectra® is an orally administered endectocide for dogs, a co-formulation of the isoxazoline afoxolaner and the macrocyclic lactone milbemycin oxime. The objective of this study was to assess the efficacy of this product against canine tungiasis. METHODS: A blinded, negative-controlled field trial was conducted in a Brazilian community known to be highly endemic for tungiasis. Sixty-six dogs naturally infected with live T. penetrans were randomly allocated to a treated group (44 dogs) and an untreated control group (22 dogs). In a first phase, dogs from the treated group were treated on days 0, 30, and 60. Efficacy was evaluated on the basis of the macroscopic parasitic skin lesions (Fortaleza classification) on days 7, 14, 21, 30, 45, 60, 75, and 90. In a second phase, to evaluate natural reinfections, all dogs were treated on day 90 and evaluated every 2 weeks thereafter until at least 30% of dogs were infected with live sand fleas. RESULTS: During the first phase, efficacy (reduction in live sand fleas) of 92.4% was demonstrated on day 7. From day 14 until day 90, the efficacy of NexGard Spectra® was 100%. In the second phase, all dogs were free of live T. penetrans from 15 until 45 days after the day 90 treatment; 60 days post-treatment, 11% of dogs were reinfected, and 75 days post-treatment, 40% of dogs were reinfected. CONCLUSIONS: NexGard Spectra® was demonstrated to be highly effective against canine tungiasis. In addition to an obvious beneficial effect on the health and welfare of the treated dog, the use of this product may have a one-health benefit on human cases by controlling the main reservoir of sand fleas.

Tungiasis: Participation of Cats and Chickens in the Dispersion and Maintenance of the Disease in an Endemic Tourist Area in Brazil.

Tunga spp. are fleas commonly found in impoverished tropical regions. In Vila Juerana, a tourist community in Ilheus, Bahia, Brazil, where tungiasis is endemic, dogs are the main host of fleas during their life cycle. However, there is no information about the role of cats and chickens in tungiasis in the village. Of the 272 households investigated, 112 had domestic animals, 48 had only dogs, 28 had only cats, and nine had only chickens. Of the 27 households with cohabitation among species, 16 had cats and dogs, eight had chickens and dogs, and three had dogs, cats, and chickens. The injuries due to tungiasis were ranked according to the Fortaleza classification, considering stages I, II, and III as viable lesions. The paws/feet of 71/111 (63.9%) cats and 173/439 (39.4%) chickens were inspected. Dogs that lived with positive cats and chickens also were inspected. Among the 38% (27/7; 95% IC 26.74-49.32) positive cats, 16 cohabited houses with infected dogs but none lived with positive chickens. Of the chickens, 2.3% (4/173; 95% IC 0.07-4.5) had lesions caused by tungiasis. In each household where a cat was infected, the dog was also positive. Two chickens cohabited with an infected dog and the other two did not coexist with other species. Cohabitation with infected dogs and the absence of house confinement restrictions in Vila Juerana make cats important carriers that spread tungiasis in this community. Chickens had a low frequency of tungiasis lesions despite living in proximity to infected dogs and cats.

Treatment of Animal Tungiasis: What's New?

In tropical and subtropical countries, particularly in disadvantaged communities, tungiasis is a severe public health problem, which is often neglected by the authorities. The sand fleas Tunga penetrans, predominant in endemic areas, and Tunga trimamillata, whose cases in humans are less frequent, are the cause of this zoonosis. Domestic animals are potential reservoirs and disseminators of tungiasis, so controlling their infection would significantly advance the prevention of human cases. This literature review compiles the most recent studies and innovations in treating animal tungiasis. Studies of approaches to the treatment of animal tungiasis, as well as disease control and prevention, are described. Isoxazolines are highlighted as promising drugs to treat animal tungiasis, with high efficacy and pharmacological protection. The positive impacts of this discovery on public health are also discussed, since dogs are an essential risk factor for human tungiasis.

Spatial Distribution of Off-Host Stages of Tunga penetrans in the Soil within the Home Range of Nine Infected Dogs in An Endemic Tourist Area in Brazil.

Tungiasis is a neglected disease caused by the sand flea Tunga penetrans, and dogs are considered the main reservoirs in Brazil. This study aimed to identify the role of dogs as tungiasis dispersers and to investigate the presence of T. penetrans in the soil of an endemic tourist area. Nine dogs infected by T. penetrans were included in this study and received GPS collars to analyze their movement through the village. Duplicate sand samples were collected in different areas of the community. Those areas were classified as peridomicile (n = 110), open area (n = 110), beach (n = 50), and river (n = 58). The analysis of the points recorded by the collars showed that the dogs roamed throughout the community, potentially facilitating the spread of the disease. Samples contaminated with developmental forms of the parasite were found in the circulation area of three dogs. Adult fleas were found in 3/328 samples. These data emphasize that infected dogs' roaming can influence the fleas' dispersion in the soil. Statistically, none of the study variables had a significant correlation (p > 0.5) with the presence of T. penetrans in the area analyzed. This study was the first to assess infected dogs' role as tungiasis propagators.

Giardiasis in children and dogs, and the first report of assemblage E in dogs from northeastern Brazil.

Diagnosis is crucial for controlling giardiasis. We determined the prevalence and genetically characterize isolates of Giardia duodenalis of children and dogs from rural communities in northeastern Brazil. G. duodenalis cysts were concentrated by centrifugal flotation/sedimentation. Molecular characterization was carried out using the loci ssu-rRNA, bg, tpi, and gdh. By parasitological techniques, Giardia spp. infection was detected in 72/192 children (37.5%; 95% CI: 30.6%-44.7%) and 24/139 dogs (17.3%; 95% CI: 11.4%-24.6%). By molecular analysis, infection was detected in 60/141 children (42.5%; 95% CI: 34.3%-51.2%) and 26/92 dogs (28.3%; 95% CI: 19.4%-38.6%). The total prevalence of giardiasis was 54.9% in children (106/193; 95% CI: 47.1%-61.6%) and 32.9% in dogs (47/143; 95% CI: 25.2%-41.2%). Zoonotic assemblages A and B of G. duodenalis were detected in children, and assemblage E of G. duodenalis was detected in one child and two dogs. Parallel use of parasitological and molecular techniques proved to be a more effective strategy for detecting giardiasis in children and dogs from endemic areas.

Efficacy of oral fluralaner (Bravecto) against Tunga penetrans in dogs: A negative control, randomized field study in an endemic community in Brazil.

The sand flea Tunga penetrans is one of the zoonotic agents of tungiasis, a parasitic skin disease of humans and animals. The dog is one of its main reservoirs. This negatively controlled, randomized, double-masked clinical trial evaluated the therapeutic and residual efficacy of fluralaner for treatment of dogs naturally infested with T. penetrans. Sixty-two dogs from an endemically affected community in Brazil were randomly assigned to either receive oral fluralaner (Bravecto chewable tablets) at a dose of 25 to 56 mg fluralaner/kg body weight, or no treatment (31 dogs per group). Dogs were clinically examined using a severity score for acute canine tungiasis (SCADT), parasitological examinations as defined by the Fortaleza classification, and pictures of lesions on days 0 (inclusion and treatment), 7 ± 2, 14 ± 2, 21 ± 2, 28 ± 2, 60 ± 7, 90 ± 7, 120 ± 7 and 150 ± 7. The percentage of parasite-free dogs after treatment was >90% between days 14 and 90 post-treatment with 100% efficacy on study days 21, 28 and 60. Sand flea counts on fluralaner treated dogs were significantly lower (p<0.025) than control dogs on all counts from day 7 to 120. The number of live sand fleas on treated dogs was reduced by > 90% on day 7, > 95% on days 14 and 90, and 100% from day 21 to 60, and with a significant difference between groups from day 7 to 120. From day 7 to day 120, mean SCADT scores were significantly reduced in treated dogs with a mean of 0.10 compared to 1.54 on day 120 in untreated dogs. Therefore, a single oral fluralaner administration is effective for treating and achieving long lasting (> 12 weeks) prevention for tungiasis in dogs.

Tungiasis in domestic, wild, and synanthropic animals in Brazil.

Tungiasis is an ectoparasitic skin disease of humans and warm-blooded animals caused by fleas of the genus Tunga (Jarocki, 1938). Dogs, cats, pigs, and synanthropic rodents are the main animal reservoirs. Of the 14 known species, 12 are found in Latin America and, among these, eight are found in Brazil, including the two zoonotic species Tunga penetrans and Tunga trimamillata. Tunga penetrans predominates among humans and Brazilian pets, where the dog is the most affected species, and its presence is a risk factor associated with the disease in humans. Tunga spp. are widely distributed throughout the national territory, with T. penetrans being the most dispersed and the most frequent in animals from endemic areas, especially in underprivileged communities. Infections in animals, associated with inadequate management, favor the spread and perpetuation of the disease. Intense injuries can result in sequelae and serious clinical conditions, compromising the health, welfare, and productivity of animals, as well as leading to death. Health precariousness, lack of control and neglect in the management of populations of domestic and synanthropic animals, poor hygiene habits of individuals, lack of information from both the population and related professionals, lack of effective treatment, and of perception of tungiasis as a disease are among the main challenges for the control of this parasitosis. As recommended for other zoonotic Neglected Tropical Diseases, strategies based on the concept of One Health can guarantee more effective results in the fight against human and animal tungiasis.

Clinical and macroscopic morphological features of canine tungiasis.

Tungiasis is a public health problem in endemic resource-poor communities, where dogs are important reservoirs of Tunga spp., contributing significantly to the process of transmission of this zoonosis. In order to optimize the diagnosis of canine tungiasis, macroscopic morphological characteristics and clinical signs of the lesions were investigated, based on the inspection of 40 dogs infested by T. penetrans from an endemic rural community in northeastern Brazil. Of the 1546 lesions found in these dogs, including all stages of development of the parasite, 89.1% (1378) were located on the paw pads. Dogs aged up to 5 years had the greatest number of lesions. Dark pigmentation and hyperkeratosis of the paw pads made it difficult to identify the lesions. Among all the clinical signs observed were hyperemia (38; 95%), pain (32; 80%), fissure (11; 27.5%), onychogryphosis (29; 72.5%), cluster of lesions (26; 65%), hyperkeratosis (25; 62.5%), lameness (15; 37.5%), and fissure (11; 27.5%). Ectopic lesions were found especially in the nipples (64; 4.1%) and abdomen (51; 3.3%). The maximum diameter of the stage III neosomes was 6 mm. Dogs with a higher number of lesions had a higher degree of hyperkeratosis. Age over 1 year was associated with a higher rate of dispersion of the parasite in the environment (p = 0.04). The identification of the initial stages of tungiasis can guarantee a more effective control of the disease in dogs, which will mainly depend on the treatment of adult animals and the application of continuous preventive actions based on One Health in these communities.

Enteric parasitic infections in children and dogs in resource-poor communities in northeastern Brazil: Identifying priority prevention and control areas.

The aim of this study was to determine the prevalence and risk factors of the main enteric parasitic infections that affect children and dogs in the municipality of Ilhéus, Bahia, Brazil; and to identify the geopolitical areas that should receive priority interventions to combat them. Between March and November 2016, fecal samples of 143 dogs and 193 children aged 1 month to 5 years were collected in 40 rural and semirural communities using a systematic sampling approach, stratified by district. Samples were collected by legal guardians of the children and / or dog owners. Eggs, larvae, cysts and oocysts of parasites were concentrated by centrifugal-flotation and centrifugal-sedimentation, and acid-resistant staining was used to visualize parasites. One hundred and thirty-two children (68.4%), 111 dogs (77.6%) and 199 (73.7%) dog fecal samples collected from streets were parasitized. Giardiasis, cryptosporidiosis, amoeba infections and hookworm were the most frequent infections in all studied populations, in addition to trichuriasis in dogs and ascaridiasis in children. A predominance of Giardia and hookworms was observed in children and dogs, respectively. The coastal districts of Aritaguá, Olivença and the main district had a higher parasitic diversity and overlapping of important potential zoonotic infections. Age over one year (p<0.001), adjusted OR = 3.65; 95% CI = 1.86-7.16) and income below the minimum monthly salary (p = 0.02, adjusted OR = 2.78, 95% CI = 1.17-6.59) were the main factors associated with intestinal parasitic infections in children and dogs, respectively. The coastal districts of Aritaguá and Olivença and the main district should be prioritized through enteric disease control programs, and the factors associated with infections must be considered in the design of health interventions in these districts. The integration between affirmative income actions and investments to improve the health infrastructure of these communities may work more effectively than current preventive measures to combat enteric parasites.

Seasonal variation and persistence of tungiasis infestation in dogs in an endemic community, Bahia State (Brazil): longitudinal study.

Tungiasis is a zoonosis neglected by authorities, health professionals, and affected populations. Domestic, synanthropic, and sylvatic animals serve as reservoirs for human infestation, and dogs are usually considered a main reservoir in endemic communities. To describe the seasonal variation and the persistence of tungiasis in dogs, we performed quarterly surveys during a period of 2 years in a tourist village in the municipality of Ilhéus, Bahia State, known to be endemic for tungiasis. Prevalence in dogs ranged from 62.1% (43/66) in August 2013 to 82.2% (37/45) in November 2014, with no significant difference (p = 0.06). The prevalence of infestation remained high, regardless of rainfall patterns. Of the 31 dogs inspected at all surveys, period prevalence was 94% (29/31; 95% CI 79.3-98.2%) and persistence of infestation indicator [PII] was high (median PII = 6 surveys, q1 = 5, q3 = 7). Dogs < 1 year of age had a higher mean prevalence of 84.5%, as compared with 69.3% in the older dogs. No significant difference was found between the risk of infestation and age or sex (p = 0.61). Our data indicate that canine tungiasis persisted in the area during all periods of the year. The seasonal variation described in human studies from other endemic areas was not observed, most probably due to different rainfall patterns throughout the year. The study has important implications for the planning of integrated control measures in both humans and animal reservoirs, considering a One Health approach.

First description of Giardia duodenalis in buffalo calves (Bubalus bubalis) in southwest region of São Paulo State, Brazil.

We performed molecular characterization of Giardia duodenalis in buffalo calves from the Southwest region of São Paulo State, Brazil. A total of 183 fecal samples of Murrah breed buffaloes up to six months of age were collected. We examined these samples by the polymerase chain reaction (PCR) targeting the small-subunit ribosomal RNA gene and positive samples were characterized using additional PCR assays targeting a portion of the beta-giardin, the glutamate dehydrogenase and the triose-phosphate isomerase genes. Based on the SSU rRNA nPCR, the presence of G. duodenalis was confirmed in 12 (6.56%) of fecal samples, of these, five, four and three samples were positive for the tpi, bg and gdh genes, respectively. Assemblage identification by sequencing was successful in 6 of 12 samples and sequence analysis showed 100% genetic similarity with G. duodenalis assemblage E. This observation represents the first detection of G. duodenalis assemblage E in buffaloes calves in Brazil.

Canine tungiasis: High prevalence in a tourist region in Bahia state, Brazil.

Tungiasis is a parasitic skin disease neglected by authorities, health professionals, and the general population. Its occurrence is significantly associated with poverty. A cross-sectional study was conducted to describe the prevalence of tungiasis, associated clinical signs and risk factors of the canine population at a tourist site in the city of Ilhéus, Bahia (northeast Brazil). All village households were visited and dogs inspected after authorization by owners. A semi-structured questionnaire was administered. Of the 114 dogs included in the study, 71 (62.3%) were infested; all of them had lesions on their pads. An ectopic lesion on the nose was observed in one dog (1.4%). The number of manipulated lesions outnumbered the number of vital and avital lesions with an average of 88.3%. Edema (95.8%) and hyperkeratosis (85.9%) were the most prevalent clinical signs. Behavioral disorders such as excessive licking (6/71; 8.5%), disobedience (1/71; 1.4%) and prostration (2/71; 2.8%) were reported. In the multi-variate analysis, semi-restricted condition of the dogs (adjusted OR=8.58; 95% CI=2.47-29.76) and the presence of sand on the compound (adjusted OR=14.23, 95% CI=2.88-70.28) were significantly associated with infestation. We concluded that, infestation with Tunga spp. is highly endemic in the canine population of the village. The low level of restrictions on dogs and the presence of sand in areas most frequented by the animals are perpetuating factors of infestation in the community, subject to integrated and multidisciplinary intervention measures.