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Background: Parasitic neglected tropical diseases (NTDs) or 'infectious diseases of poverty' continue to affect the poorest communities in the world, including in the Philippines. Socio-economic conditions contribute to persisting endemicity of these infectious diseases. As such, examining these underlying factors may help identify gaps in implementation of control programs. This study aimed to determine the prevalence of schistosomiasis and soil-transmitted helminthiasis (STH) and investigate the role of socio-economic and risk factors in the persistence of these diseases in endemic communities in the Philippines., Methods: This cross-sectional study involving a total of 1,152 individuals from 386 randomly-selected households was conducted in eight municipalities in Mindanao, the Philippines. Participants were asked to submit fecal samples which were processed using the Kato-Katz technique to check for intestinal helminthiases. Moreover, each household head participated in a questionnaire survey investigating household conditions and knowledge, attitude, and practices related to intestinal helminthiases. Associations between questionnaire responses and intestinal helminth infection were assessed., Results: Results demonstrated an overall schistosomiasis prevalence of 5.7% and soil-transmitted helminthiasis prevalence of 18.8% in the study population. Further, the household questionnaire revealed high awareness of intestinal helminthiases, but lower understanding of routes of transmission. Potentially risky behaviors such as walking outside barefoot and bathing in rivers were common. There was a strong association between municipality and prevalence of helminth infection. Educational attainment and higher "practice" scores (relating to practices which are effective in controlling intestinal helminths) were inversely associated with soil-transmitted helminth infection., Conclusion: Results of the study showed remaining high endemicity of intestinal helminthiases in the area despite ongoing control programs. Poor socio-economic conditions and low awareness about how intestinal helminthiases are transmitted may be among the factors hindering success of intestinal helminth control programs in the provinces of Agusan del Sur and Surigao del Norte. Addressing these sustainability gaps could contribute to the success of alleviating the burden of intestinal helminthiases in endemic areas., (© 2024. The Author(s).)

Cryptosporidium and G iardia are recognized as significant etiological agents of diarrheal outbreaks in humans as these parasites may be transmitted through the ingestion of water and food contaminated with feces of human or animal origin. However, surveillance studies on the role of animal reservoirs in the transmission of Cryptosporidium and Giardia are deemed insufficient and the complete dimension of the problem contributing to contamination in an agricultural setting is unknown. This study aimed to assess the presence of Cryptosporidium and Giardia in domesticated animals from selected farms in the agricultural provinces of Laguna and Quezon in Southern Luzon, Philippines. Using immunofluorescence assay, an overall 85.7% incidence of protozoan infection was recorded among the animals ( N  = 161). Of these, 77.0 and 73.9% were positive for Cryptosporidium and Giardia, respectively. Highest incidence (95.83%) of Cryptosporidium was documented in swine and the highest incidence (89.47%) of Giardia was observed in ruminants. Analyses revealed significant differences in the incidence of the protozoan parasites among animals with different containment status, water source, age group, and sex. On the other hand, farm workers' knowledge on parasite transmission was negatively correlated ( p  = 0.001) to parasite incidence. With the scarcity of data about Cryptosporidium and Giardia in farm-raised animals in the Philippines, the information obtained from this study will be vital for protozoan source tracking and further control interventions against Cryptosporidium and Giardia infections., Competing Interests: Conflict of interestAll authors have no relevant financial or non-financial interests to disclose., (© Indian Society for Parasitology 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Bats are often associated with several zoonotic diseases, including helminth infections. Despite their potential detrimental effects on both human and bat populations, information on helminth parasites of Philippine bats remains scarce. Here, we identify gastrointestinal helminths parasitizing bats collected from a cave complex in Cavinti, Laguna Province, Philippines, determine their prevalence (P) and mean intensity (MI), and investigate relationship of helminth prevalence and intensity with bat host characteristics including sex, diet, age, and roosting habit. We isolated 581 individuals of helminths representing six taxa (three trematodes, two nematodes, one cestode) from the gastrointestinal tract of sampled bats. Helminths were observed in 82 out of 172 bats captured (P = 47.67%), with Miniopteruspaululus having the highest infection rate (P = 91.3%) and highest MI (18 ± 4.5/infected bat). Helminths parasitizing endemic bat species from the Philippines, such as Rhinolophus rufus , Rhinolophus inops , Hipposideros pygmaeus , and Ptenochirus jagori were reported here for the first time. We provide new host records for other helminth species and report the presence of two parasites, Plagiorchis sp. and Toxocara sp., known for their zoonotic potential. These data will contribute to efforts in identifying parasites and diseases harbored by bats in the country and develop additional conservation measures for bats., Competing Interests: Conflict of Interest The authors declare that they have no conflict of interest., (© 2024 R. A. J. Duco et al., published by Sciendo.)

Background: The giant roundworm Ascaris is an intestinal nematode, causing ascariasis by infecting humans and pigs worldwide. Recent estimates suggest that Ascaris infects over half a billion people, with chronic infections leading to reduced growth and cognitive ability. Ascariasis affects innumerable pigs worldwide and is known to reduce production yields via decreased growth and condemnation of livers. The predominant anthelminthic drugs used to treat ascariasis are the benzimidazoles. Benzimidazoles interact with β-tubulins and block their function, and several benzimidazole resistance-associated mutations have been described in the β-tubulins of ruminant nematodes. Recent research on ascarids has shown that these canonical benzimidazole resistance-associated mutations are likely not present in the β-tubulins of Ascaris, Ascaridia or Parascaris, even in phenotypically resistant populations., Methods: To further determine the putative absence of key β-tubulin polymorphisms, we screened two β-tubulin isotypes of Ascaris, highly expressed in adult worms. Using adult and egg samples of Ascaris obtained from pigs and humans worldwide, we performed deep amplicon sequencing to look for canonical resistance-associated mutations in Ascaris β-tubulins. Subsequently, we examined these data in closer detail to study the population dynamics of Ascaris and genetic diversity within the two isotypes and tested whether genotypes appeared to partition across human and pig hosts., Results: In the 187 isolates, 69 genotypes were found, made up of eight haplotypes of β-tubulin isotype A and 20 haplotypes of isotype B. Single nucleotide polymorphisms were seen at 14 and 37 positions for β-tubulin isotype A and isotype B, respectively. No evidence of any canonical benzimidazole resistance-associated mutations was found in either human- or pig-derived Ascaris isolates. There was, however, a difference in the genetic diversity of each isotype and distribution of β-tubulin genotypes between human- and pig-derived Ascaris. Statistical tests of population differentiation show significant differences (p < 0.001) between pig- and human-derived worms; however, more diversity was seen between worms from different populations than worms from different hosts., Conclusions: Our work suggests an absence of canonical β-tubulin mutations within Ascaris, but alternative modes of anthelminthic resistance may emerge necessitating continued genetic scrutiny alongside monitoring of drug efficacy., (© 2024. The Author(s).)

The continuous challenges of land use change have brought potential threats to biodiversity and the spread of zoonotic diseases. In this study, synanthropic rodents and their helminth parasites were used as sentinels to assess the potential impact of land use on zoonosis. Rats were collected in different ecosystems, namely agricultural, agroforest, and residential areas in the northeastern sub-watersheds of Mount Makiling, Laguna, Philippines. Three (3) species of rats were captured, namely, Rattus tanezumi, Rattus norvegicus, and Rattus exulans . Of the total 180 rats collected, 92.7 % were found infected with helminth parasites, namely Hymenolepis diminuta, Hymenolepis nana, Taenia pisiformis, and Strobilocercus fasciolaris (cestodes); Angiostrongylus cantonensis, Nippostrongylus brasiliensis , Strongyloides ratti, Capillaria hepatica, Trichuris muris , and Rictularia sp. (nematodes); and Echinostoma ilocanum (trematode). Of these 11 species, nine (9) were considered zoonotic. This study provides important information on the helminth parasites of rats in the northeastern sub-watersheds of Mount Makiling and the potential threat of zoonotic transmission due to increasing land use change and urbanization in the area. Moreover, urbanization can provide favorable eco-epidemiological conditions for rodent-borne pathogens, such as parasites, that are seriously threatening agricultural settings and human settlements in these areas., Competing Interests: Conflict of Interest Authors state no conflict of interest., (© 2024 V. G. V. Paller et al., published by Sciendo.)

Toxocariasis is a zoonotic disease caused by Toxocara spp. from dogs and cats. The Philippines is among the countries recorded to have abundant stray cats and dogs; however, few studies have been done to elucidate the transmission dynamics and the potential risks associated with toxocariasis. This study was conducted in a rural village in Los Baños, Laguna, Philippines to determine the prevalence of toxocariasis among selected public schoolchildren and identify some risk factors that can contribute to the transmission dynamics of toxocariasis in the study site. To elucidate this, serum samples from 50 public school children (ages 8-13) were tested using a Toxocara canis IgG ELISA kit, while 60 randomly selected households were chosen for collection of soil and dog samples. Sixty soil and dog fecal samples were collected and processed through modified sucrose flotation technique and formalin-ethyl acetate concentration technique, respectively. Knowledge, attitudes and practices (KAP) survey was conducted per household to determine potential risk factors. Results revealed that 60% of the public-school children examined were positive for anti- Toxocara canis antibodies, while 38.3% of the soil samples and 28% of the dog fecal samples were found positive for contamination with Toxocara ova. Deworming of pets was found to be significantly correlated to risk factors of infection ( p  < 0.05). This study highlights the potential risks of toxocariasis infection of residents in rural communities. Strict implementation of ordinances related to responsible pet ownership as well as promotion of sanitation and hygiene should be employed., Competing Interests: Conflict of interestThe authors declare that there is no conflict of interest., (© Indian Society for Parasitology 2022.)

There are relatively few studies on parasite fauna of marine fishes in Philippine waters. This study aimed to determine the prevalence of marine ascaridoid infection in Decapterus species in Balayan Bay and Tayabas Bay. A total of 371 fishes belonging to three different species of Decapterus ( D. tabl [ n = 130], D. macrosoma [ n = 121], and D. maruadsi [ n = 120]) were collected. Ascaridoid parasite larvae were found in all fish host species, with an overall fish infection rate of 22%. The highest infection rate was observed in D. tabl (27.69%), followed by D. macrosoma (19%), and then D. maruadsi (17.50%). Moreover, a higher prevalence of infection was detected in Tayabas Bay (27.57%) than in Balayan Bay (15.59%). Molecular analyses based on the ITS2 and 18S rRNA gene supported the identification of the larvae into two species: Anisakis typica and Raphidascaris ( Ichthyascaris ) lophii . This is the first report of the genetic identification of these two helminth parasites in Decapterus fish species in the Philippines. Paucity in the database of Philippine marine fish parasites warrants more research efforts, especially concerning economically important fish species with implications to food safety and food security., Competing Interests: Conflict of interest The authors have declared that no competing interests exist., (© 2022 Dela Cruz et al. published by Sciendo.)

Fresh vegetables are an important part of a healthy diet, however, they can also be agents of transmission of intestinal parasites. This study aimed to evaluate the presence of parasite contamination in vegetable farms as a source of transmission in selected rural communities in Laguna, Philippines. A total of 168 vegetable, 55 soil and 15 water samples collected from four selected farms and a reference farm were processed through various standard parasitological techniques. Of these, 17.3% of vegetables, 47.3% soil and 73.3% water samples were found contaminated with parasites’ eggs or cysts. Interestingly, leafy vegetables, such as lettuce, were found to be more contaminated. Results showed that strongylids/hookworms (egg/larva) showed the highest prevalence in farm soil (38.2%) and vegetable (13.1%); other helminth parasite eggs were also recovered such as Toxocara sp., Ascaris sp., Trichiuris, Trichostrongylus sp. and protozoan cysts of Balantidium coli. Cryptosporidium sp. oocysts of and Giardia sp. cysts were observed in all water samples in the farms. Furthermore, results revealed that some farming practices such as the use of improperly treated animals manure as fertilizers, unhygienic practice of farmers and sanitation issues were factors that contribute to parasite contamination in the farms. These findings have implications on food safety in poor-resource communities posing public health risks. Recommendations were discussed in the study for the control and prevention of parasite contamination at the farm level.

This study is the first investigation of parasites and other pathogens present in Sunda leopard cats ( Prionailurus javanensis ) in Aborlan, Palawan, Philippines. With the nature of wild carnivore sampling, four (4) wild Sunda leopard cats were captured in Aborlan, Palawan, Philippines for a period of nine (9) months. Of these, three (3) were considered for blood and fecal examination due to the poor condition of one animal. Rapid diagnostic kits were used to detect the presence of selected pathogens in blood samples while fecal samples were examined for parasite fauna and diet contents. Nine (9) parasite species were identified namely: Toxoplasma gondii , Ancylostoma sp., Capillaria hepatica , Echinostoma sp., Hymenolepis nana , Isospora felis , Physaloptera sp., Trichostrongylus sp., and a fasciolid. Chlamydophila felis , a bacterial pathogen was also detected in the blood. No individuals were found to be positive for feline immunodeficiency virus, feline infectious peritonitis virus, and feline leukemia virus antibodies. Six (6) small mammal prey species were identified from the feces of Sunda leopard cats namely: Palawan spiny rat ( Maxomys panglima ), Asian house rat ( Rattus tanezumi ), Polynesian rat ( Rattus exulans ), house mouse ( Mus musculus ), Southern Palawan tree squirrel ( Sundasciurus steerii ), and Palawan treeshrew ( Tupaia palawanensis ). Sunda leopard cats in Aborlan, Palawan, may be highly infected by parasites primarily due to their diet of small mammals such as rodents. Transmission is also possible through environmental contact with contaminated water or soil or direct physical contact with infected domestic animals. This paper contributes to the knowledge on host-parasite systems in wildlife ecosystem in the Philippines which is extremely poorly understood., Competing Interests: Conflicts of interestThe authors declare that they have no competing interests. Disclosure forms included., (© Springer Nature India Private Limited part of Springer Nature 2021.)

A number of studies had been conducted on rat species diversity in the Philippines, however, there is a dearth of information on the extent of Angiostrongylus spp. infection in various ecological niches. Collection of non-native rat samples occurred in various sampling sites categorized as residential, agricultural and agro-forest in Philippine Mount Makiling Forest Reserve (MMFR) and its adjacent areas . Three species of non-native rats were captured including Rattus tanezumi, Rattus norvegicus and Rattus exulans. Of the total 90 non-native rats collected, 24.4% were found infected with Angiostrongylus cantonensis. Statistical analysis showed significant difference among rat species with highest prevalence observed in R. exulans (42.9%) followed by R. tanezumi (29.8%) and R. norvegicus (7.7%) (P = 0.047). Angiostrongylus cantonensis infection was significantly higher in adults (29.4%) than in juvenile rats (9.1%) (P = 0.050). However, results showed no significant difference in A. cantonensis infection between male (43.3%) and female (18.3%) rats and between wet (31.6%) and dry seasons (19.2%) (P > 0.05). Moreover, this study also revealed that rats from agricultural and agro-forest areas showed significantly higher prevalence than residential areas. With urbanization and the everchanging landscape of MMFR watersheds and buffer zones, zoonotic transmission can pose health threats to the local people.

Rats are recognized as reservoir hosts of several pathogens that pose a threat to human health. Although rats are reported to be hosts of a large number of pathogens, a survey of Capillaria hepatica carried by rats in various settings such as residential, agroforestry, and agricultural areas in the Philippines has not been conducted. A total of 90 rats composed of Rattus norvegicus , Rattus tanezumi , and Rattus exulans were collected through trapping in selected residential, agroforestry, and agricultural areas in Los Baños Laguna, Philippines. The overall prevalence of C. hepatica among rats was 21.11%. Among the rat species collected, R. norvegicus showed the highest prevalence (55.56%), followed by R. exulans (14.29%), then R. tanezumi (5.36%) (differences significant at p  < 0.05). Moreover, residential areas had the highest prevalence of C. hepatica infection (50%), followed by agroforestry and agricultural areas at 6.7% each (significant at p  < 0.05). However, the difference in C. hepatica infection between male (11.43%; 4/35) and female (27.27%; 15/55) rats was not significant ( p  > 0.05). Most of the infected rats were moderately infected (68.42%), while few were lightly and severely infected (15.78% each). Lastly, the presence of C. hepatica in liver is suggestive of presence of lymphocytes, amyloid, granuloma, and the occurrence of necrosis, hypertrophy, fibrosis, and cholestasis in the liver of the host. Capillariasis could be occurring in Philippine human populations, hence there is need for screening the population with appropriate means and to create awareness of this emerging disease., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest., (© Indian Society for Parasitology 2020.)

Intestinal helminths are extremely widespread and highly prevalent infections of humans, particularly in rural and poor urban areas of low and middle-income countries. These parasites have chronic and often insidious effects on human health and child development including abdominal problems, anaemia, stunting and wasting. Certain animals play a fundamental role in the transmission of many intestinal helminths to humans. However, the contribution of zoonotic transmission to the overall burden of human intestinal helminth infection and the relative importance of different animal reservoirs remains incomplete. Moreover, control programmes and transmission models for intestinal helminths often do not consider the role of zoonotic reservoirs of infection. Such reservoirs will become increasingly important as control is scaled up and there is a move towards interruption and even elimination of parasite transmission. With a focus on southeast Asia, and the Philippines in particular, this review summarises the major zoonotic intestinal helminths, risk factors for infection and highlights knowledge gaps related to their epidemiology and transmission. Various methodologies are discussed, including parasite genomics, mathematical modelling and socio-economic analysis, that could be employed to improve understanding of intestinal helminth spread, reservoir attribution and the burden associated with infection, as well as assess effectiveness of interventions. For sustainable control and ultimately elimination of intestinal helminths, there is a need to move beyond scheduled mass deworming and to consider animal and environmental reservoirs. A One Health approach to control of intestinal helminths is proposed, integrating interventions targeting humans, animals and the environment, including improved access to water, hygiene and sanitation. This will require coordination and collaboration across different sectors to achieve best health outcomes for all., (© 2020 Elsevier Ltd. All rights reserved.)

The common dog roundworm Toxocara canis can infect other animals and humans which may act as their paratenic and accidental hosts, respectively. Larvae do not further develop to adult worms in these hosts. Instead, they undergo migration to various body organs, causing the neglected parasitic disease known as toxocariasis. Although rats are considered as potential paratenic hosts of the parasite, there are only few studies which utilized Rattus norvegicus (Sprague-Dawley strain) for experimental infections involving toxocariasis. This study aimed to determine whether T. canis could establish in Sprague-Dawley rats artificially infected with 500 T. canis embryonated eggs and if the animals can be used as animal models for toxocariasis. Following squash method and tissue digestion, larvae were recovered from the lungs, liver and brain of the infected rats. Furthermore, gross examination of organs revealed macroscopic lesions and hemorrhages in the lungs and brain. Microscopically, accumulation of inflammatory cells, thickening of alveoli lining and destruction of bronchial walls and hepatic necrosis were observed. This study showed that T. canis has established in Sprague-Dawley rats and could serve as a model for Toxocara infection studies., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest., (© Indian Society for Parasitology 2019.)

Soils from selected organic and conventional farms in the Philippines were examined for parasite contamination. A total of 600 soil samples from twenty organic and conventional farms were collected and processed through modified sucrose floatation technique. Results revealed that 248 out of 600 (41.33%) soil samples were contaminated with parasite eggs. Parasites recovered were Ascaris spp. (39.0%), Trichuris spp. (26.0%), hookworm/strongylid (22.0%), Toxocara spp. (4.0%), Taenia spp. (3.0%), and some unidentified eggs (6.0%). Contamination rate was found higher in organic (48.30%) than in conventional farms (37.67%) ( p  = 0.834; not significant); and significantly higher in Southern (64.40%) than in Northern Luzon region (31.40%) ( p  = 0.015). In addition, contamination rate between soil depths was not statistically significant ( p  = 0.24), with depth 1 (0-5 cm) at 43% and depth 2 (6-10 cm) at 39.67%. Furthermore, some farming practices were recorded through survey and results revealed that the use of manure as fertilizer ( p  = 0.017) and wash water ( p  = 0.014) showed significant positive relationship with parasite contamination in soil. These findings have implications on food safety and could be used to help the agriculture sector and other stakeholders in their efforts to improve food safety policies., (© 2019 Published by Elsevier Ltd on behalf of World Federation of Parasitologists.)

Freshwater snails serve as one of trematodes' intermediate hosts. Previous studies on trematode larval stages in the Philippines have largely focused on species with public health importance. This study sought to investigate the prevalence of cercarial morphotypes in several freshwater snail species found in different habitat types (rice field, irrigation canals, and residential area) in selected agricultural areas in Los Baños and Bay in Laguna. Cercarial emergence was induced through exposure to artificial light. A total of 2,720 freshwater snails were collected and were represented by seven species, namely, Melanoides tuberculata Muller 1774 (n = 1229), Radix quadrasi von Moellendorf (n = 630), Tarebia granifera Lamarck, 1816 (n = 417), Pomacea canaliculata Lamarck 1819 (n = 257), Vivipara angularis philippinensis Nevill (n = 18), Stenomelania sp. (n = 104), Thiara scabra Muller 1774 (n = 65). A 2.57 % over-all prevalence was recorded; the infected snail species were M. tuberculata (2.21 %), R. quadrasi (0.21 %), T. granifera (0.11 %). Four cercarial morphotypes, namely, Parapleurolophocercous cercaria (1.80 %), Virgulate xiphidiocercaria (0.26 %), Megaluruous cercaria (0.29 %), and Echinostome cercaria (0.22 %) were recovered from the infected snail species. Prevalence of cercarial infection was significantly different (p < 0.05) among habitat types., Competing Interests: Conflict of Interest Authors state no conflict of interest., (© 2019 V. G. V. Paller, J. R. M. Macaraig, R. T. Verona, L. A. Estaño, published by Sciendo.)

Rattus tanezumi and Rattus norvegicus are the most common rodent species in the Philippines, with the former mainly inhabiting agricultural land and the latter in urban areas. Generating information on the Angiostrongylus cantonensis harbored by these rodents would be useful for public health. A total of 600 rodents were collected from traps placed each month from July to December 2012 in selected villages of Muñoz, Nueva Ecija; the rice granary of the Philippines. The prevalence of A. cantonensis in R. tanezumi and R. norvegicus was, 100%; all the rodents from the five villages were infected. The study shows that regardless of stages, body weight and length, rodents are vulnerable to infection by Angiostrongylus cantonensis present in the environment. However in terms of sex, results revelead that the male and female in R. tanezumi has no statistically significance while R. norvegicus revealed that male and female has statistically significance. This study also show that, rodents that were caught in the agricultural area has higher mean intensity compared to rodents that were trapped in the residential areas but found to be insignificant. Also through survey interviews the various risk factors with zoonotic implication of A. cantonensis in the area was also discussed., Competing Interests: Compliance with ethical standardsAll authors declares that they have no conflict of interest.

Toxocariasis is a zoonotic disease usually caused by dog and cat roundworms, Toxocara canis and T. cati. Detection and diagnosis is difficult in paratenic and accidental hosts, including humans, as they cannot be detected through conventional methods such as fecal examination. Diagnosis therefore relies on immunological methods and molecular methods such as enzyme-linked immunosorbent assay (ELISA) and Western Blot, which are both time-consuming and requires sophisticated equipment. In the Philippines, only a few studies are available on Toxocara seroprevalence. Therefore, there is a need to adapt methods for serodiagnosis of Toxocara infection in humans for the Philippine setting. A dot enzyme linked immunosorbent assay (dot-ELISA) was standardized using T. canis excretory-secretory antigens. Test sera were collected from laboratory rats (Sprague-Dawley strain) experimentally infected with embryonated eggs of T. canis and Ascaris suum as well as rice field rats naturally infected with Taenia taeniaeformis and Nippostrongylus sp. Optimum conditions used were 20 µg/ml antigen concentration and 1:10 serum dilution. The sensitivity, specificity, positive, and negative predictive values were 90% (95% CI 55.5-99.7%), 100% (95% CI 69.2-100.0%), 100% (95% CI 66.4-100%), and 90.9% (95% CI 58.7-99.8%), respectively. Dot-ELISA has the potential to be developed as a cheaper, simpler, and more practical method for detection of anti- Toxocara antibodies on accidental hosts. This is a preliminary study conducted on experimental animals before optimization and standardization for human serum samples.