Intestinal Helminth Parasites Research Articles

Gut microbiota metabolically mediate intestinal helminth infection in Zebrafish.

Intestinal helminth parasite (IHP) infection induces alterations in the composition of microbial communities across vertebrates, although how gut microbiota may facilitate or hinder parasite infection remains poorly defined. In this work we utilized a zebrafish model to investigate the relationship between gut microbiota, gut metabolites, and IHP infection. We found that extreme disparity in zebrafish parasite infection burden is linked to the composition of the gut microbiome, and that changes in the gut microbiome are associated with variation in a class of endogenously-produced signaling compounds, N-acylethanolamines, that are known to be involved in parasite infection. Using a statistical mediation analysis, we uncovered a set of gut microbes whose relative abundance explains the association between gut metabolites and infection outcomes. Experimental investigation of one of the compounds in this analysis reveals salicylaldehyde, which is putatively produced by the gut microbe Pelomonas, as a potent anthelmintic with activity against Pseudocapillaria tomentosa egg hatching, both in vitro and in vivo. Collectively, our findings underscore the importance of the gut microbiome as a mediating agent in parasitic infection and highlights specific gut metabolites as tools for the advancement of novel therapeutic interventions against IHP infection.

PREVALENCE OF ECTO AND ENDO PARASITES OF WHITE CATFISH (AMEIURUS CATUS) IN UKE RIVER, KARU LOCAL GOVERNMENT AREA OF NASARAWA STATE, NIGERIA

In Uke River, Karu Local Government Area, Nasarawa State, Nigeria, a six-month research was carried out between January and June 2023 to examine the gills and intestinal helminth and protozoan parasites of White Catfish (Ameiurus catus). A total of 100 fresh Ameiurus catus fish samples of both sexes, were obtained from the fishermen and conveyed to the Zoology laboratory of Nasarawa State University for examination. The fishes were processed and examined using gills, oesophagus, intestine and rectum. Twenty-two (22) out of 100 fishes were found to be infected with helminth and protozoan parasites and a total of 31 parasites were isolated belonging to protozoa (Eimeria spp, Hexamita spp, Protoopalina spp), nematode (Procamallanus spp), trematode (Dactylogyrus spp), Cestode (Diphyllobothrium latum, Bothriocephalus claviceps) taxonomic groups. The findings indicated that Ameiurus catus intestine contained a greater quantity of fish parasites (96%). A nematode (Procamallanus spp.) was found to have the highest prevalence of 45.16%. Although the Chi square results showed no significant difference (p>0.05), the prevalence in Ameiurus catus was greater in female samples (63.64%) compared to male samples (36.36%). Fish weighing between 151-200 g (46.14%) and measuring between 21-30 cm (28.57%) had the highest percentage of parasite infection. Going forward, it is imperative to properly cook Ameiurus catus from the Uke River to prevent the spread of parasites to consumers. Additionally, it is advisable to steer clear of any potential actions that could contribute to the parasite predominance near the water body.

Intestinal helminth parasites of Felis catus in Syangja, Nepal

Domestic cats can be infested by a huge range of parasite species, leading to a range of diverse clinical signs and symptoms. However, a comprehensive understanding of these endoparasites, particularly in the context of multiparasitism, remains limited. The aim of the study was to determine the prevalence of intestinal helminth parasites on domestic cats in Arjunchaupari Rural Municipality of Syangja District, Nepal. The study was carried out from November 2017 to June 2018. A total of 30 fresh feline fecal samples were collected and examined by using the Saline wet method and sedimentation technique. Overall, 21 (70%) fecal samples were found to be positive for different parasitic infections. Four different helminth parasitic species were encountered as Toxocara cati (40%), Toxascaris leonina (16.67%), and Ancylostoma tubaeforme (10%) belonging to nematodes and a species of cestode: Hymenolepis diminuta (6.67%). Nematode infection (66.67%) was found to be comparatively more common than cestode infection (6.67%). Statistically, the relationship between the cestode and nematode parasite is significant (x2 = 0.232, p>0.05). The high incidence of parasitism of cats was due to the relative influence of behaviour and a contaminated environment since these cats lived in the same environment as other domestic animals. The study recommended that studies on all kinds of gastrointestinal parasites, including protozoan parasites, would be better to get more knowledge about parasites and their risk of transmission.

Intestinal helminthic parasites in Columba livia (Columbiformes: Columbidae) in southern Brazil: do seasons influence helminth infections in the Neotropical region?

Objective: The aim of this study was to analyze intestinal helminthic infections in pigeons Columba livia Gmelin, 1789 (Columbiformes: Columbidae) which were collected in three different seasons in southern Brazil. Material and methods: Ninety birds (hosts) were captured in the urban area in Pelotas, Rio Grande do Sul (RS) state, Brazil, in autumn, winter and spring in 2018 and 2019. Results: Helminths species and their prevalences were: Ascaridia columbae (33.33%), Baruscapillaria obsignata (23.33%) (Nematoda), Brachylaima mazzantii (3.33%) (Digenea), Skrjabinia sp. (11.11%) and Killigrewia sp. (3.33%) (Cestoda). Prevalence and mean intensity of infection in the three collection periods did not show any significant difference, except A. columbae, which was more prevalent in autumn than in spring. Conclusion: Results showed that abiotic and environmental conditions found in the region were suitable for the development of intestinal helminths associated with C. livia in the sampling periods in southern Brazil.

Intestinal parasites in dogs from a Guarani indigenous village in Paraná, Brazil

Animals can serve as reservoirs for various zoonotic diseases, with domestic animals standing out as potential sources of contamination and the spread of parasite eggs and cysts due to their close and constant contact with humans. Indigenous populations culturally keep canines in their homes, as they are seen as "man's best friend" and guardians against nocturnal creatures, symbolizing security and companionship. However, canines frequently become infected with intestinal protozoa and helminth parasites, therefore, the objective of this research was to establish the parasitological profile of canines in the Guarani indigenous population, specifically in the Santa Rosa do Ocoy Village in western Paraná, and correlate with human population risk of infection. Fresh fecal samples were collected, which the animals defecated spontaneously without the need for direct contact. Macroscopic analyses were performed, and then the samples were subjected to parasitological analysis using the ether-formaline centrifugal-flotation and the flotation in zinc sulfate. It was observed that more prevalente was Ancylostomatides and Toxocara canis, Giardia duodenalis, Coccidia, Amoebas, and Trichuris was too observed. In addition to the high prevalence of parasites of the genus Toxocara and hookworms, which can penetrate the human skin and cause cutaneous larva migrans (creeping eruption), the presence of protozoa such as Giardia duodenalis, an importante diarrea infectious agente in humans, was also identified.

Prevalence of gastrointestinal helminth parasites in rhesus macaques and local residents in the central mid-hills of Nepal.

Rhesus macaques (Macaca mulatta) are distributed across Nepal in close association with humans and with a high probability of sharing of soil-transmitted intestinal helminth parasites. This study was carried out to determine the prevalence, richness and risk factors of gastrointestinal (GI) helminth parasites among rhesus macaques and humans in the Daunne Forest area, a community managed forest in the central mid-hills of Nepal. A total of 190 fecal samples, including 120 samples from rhesus macaques residing around the Daunne Devi Temple and in the surrounding forest, and 70 from local people, were microscopically examined by direct wet mount, floatation and sedimentation methods. Seasonal and age-sex based variations in helminth parasite prevalence were analyzed. Among the rhesus macaques, the total parasite prevalence was 39.2 %. Strongyloides sp. accounted for the highest prevalence (19.17 %) followed by Ascaris sp. (13.33 %), hookworm (10.83 %) and Trichuris sp. (4.17 %). Among the humans, Ascaris lumbricoides (11.3 %) was the only parasite detected. The Sorenson's coefficient of similarity of GI parasites between the macaques and local people at the generic level was 0.4. Mean parasite richness for the macaques was 1.21 ± 0.41 (SD) per infected sample. Parasite prevalence in the summer season (41.4 %) was higher than in the winter season (36 %). Adult macaques (41.67 %) had higher GI parasite prevalence than the young (30.77 %) and infants (27.27 %). Among the adult macaques, the prevalence rate was significantly higher (P=0.005) in females (52.46 %) than in males (22.86 %). Our results indicate that the temple rhesus macaques have a high prevalence of GI helminth parasites and could pose a potential zoonotic risk. As such, the need for routine monitoring and an effective management strategy is essential.

Cooperation of ILC2s and TH2 cells in the expulsion of intestinal helminth parasites.

Type 2 immune responses form a critical defence against enteric worm infections. In recent years, mouse models have revealed shared and unique functions for group 2 innate lymphoid cells and T helper 2 cells in type 2 immune response to intestinal helminths. Both cell types use similar innate effector functions at the site of infection, whereas each population has distinct roles during different stages of infection. In this Perspective, we review the underlying mechanisms used by group 2 innate lymphoid cells and T helper 2 cells to cooperate with each other and suggest an overarching model of the interplay between these cell types over the course of a helminth infection.

Cytokine Gene Expression Profiles during HIV and Helminth Coinfection in Underprivileged Peri-Urban South African Adults.

Intestinal helminth parasites are potent stimulators of T helper type 2 (Th2) and regulatory Th3 anti-inflammatory immune responses, while human immunodeficiency virus (HIV) infections are activators of predominantly T helper type 1(Th1) pro-inflammatory responses. Studies investigating the immune profiles of individuals coinfected with helminths and HIV are scarce. Although it is well known that helminths cause a type 2 immune response during the chronic stage of infection that is characterised by Th2 cell differentiation, eosinophil recruitment, and alternative macrophage activation, the immune mechanisms that regulate tissue damage at the time of parasite invasion are poorly understood. The aim of the study was to determine the cytokine gene expression profiles during HIV and helminth coinfection in underprivileged South African adults living in a peri-urban area with poor sanitary conditions and a lack of clean water supply. Study participants (n = 164) were subdivided into uninfected controls, HIV-infected, helminth-infected, and HIV and helminth-coinfected groups. The Kato-Katz and Mini Parasep techniques and Ascaris lumbricoides-specific Immunoglobulin E (IgE) and Immunoglobulin G4 (IgG4) levels were used to detect helminth infections. Participants' HIV status was determined using two HIV1/2 antibody test kits. RNA was isolated from white blood cells for cytokine (Th1-, Th2-, and Th17-related) and transcription factor gene expression profiling using real-time PCR. Multivariate regression data were adjusted for age, gender, BMI, antiretroviral treatment (ART), and nutritional supplement intake. The HIV and helminth-coinfected group had significantly higher tumour necrosis factor alpha (TNF-α) (adjusted β = 0.53, p = 0.036), interleukin 2 (IL-2) (adjusted β = 6.48, p = 0.008), and interleukin 17 (IL-17) (adjusted β = 1.16, p = 0.001) levels and lower GATA binding protein 3 (GATA3) levels (adjusted β = -0.77, p = 0.018) compared to the uninfected controls. No statistical significance was noted for Th2-related cytokines. The coinfected group had higher proinflammatory Th1- and Th17-related cytokine gene expression profiles compared to the uninfected controls. The findings suggest that pro-inflammatory responses are elevated during coinfection, which supports the hypothesis that helminths have a deleterious effect on HIV immune responses.

The worldwide prevalence of intestinal helminthic parasites among food handlers: A systematic review and meta-analysis

The worldwide prevalence of intestinal helminthic parasites among food handlers: A systematic review and meta-analysis

Prevalence and risk factors for prenatal parasitic infections and anaemia among pregnant women in Kaduna State, Nigeria

In developing nations, anaemia is one of the most prevalent medical conditions. It has long been known that parasite infection during pregnancy is one of the main causes of anaemia and an elevated risk of maternal mortality. To ascertain the prevalence and risk factors related to parasite infections and anaemia among pregnant women receiving prenatal care in some selected public health facilities in Kaduna State, Nigeria, an eleven-month cross- sectional study of 180 consenting pregnant women was conducted from February to December 2017. A standardized questionnaire was used to interview the sampled pregnant women. Stool and blood samples of each consented pregnant woman were collected. Formal-ether sedimentation technique, thin and thick blood smears and haematocrit packed cell volume capillary methods were used to screen intestinal helminth parasites, plasmodium species and Packed Cell Volume (PCV) respectively. The result obtained showed parasitic infections prevalence of 102(56.7%) among the study population. Prevalence of Plasmodium species, hookworm, Ascaris lumbricoides and those with co-infection all occurred at 47.2%, 16.7%, 17.8% and 25.0% respectively. Age, educational level, trimester and parity were all significant predictors of Plasmodium species prevalence (p<0.005). Similarly, parity and educational level were significantly (p<0.005) associated with the prevalence of intestinal parasites and co-infection. Anaemia was present in 40.0% of the examined pregnant women. Trimester and educational level were highly significant (p<0.001) predictors of anaemia among the sampled pregnant women. Plasmodium species were the most common parasitic species associated with anaemia as 43.1% of Plasmodium species-infected pregnant women had anaemia compared to those with intestinal helminth infection (30.6%) and co-infection (13.3%). However, statistical analysis revealed a significant association (p<0.05) between the prevalence of anaemia and intestinal helminth infection. Therefore, measures such as improved sanitation and health education are needed to lessen the prevalence of parasitic infections and parasite-related anaemia in the study area.

Malarial and intestinal parasitic co-infections in indigenous populations of the Brazilian Amazon rainforest

The Brazilian Amazon rainforest region has a significant prevalence of malarial and intestinal parasitic infections in indigenous populations, accounting for a disproportionate burden. Thus, a cross-sectional study was conducted to assess the prevalence and association between malarial and intestinal protozoan and helminth infections in four remote indigenous villages in the Brazilian Amazon Forest. A total of 430 individuals participated in the study, and Plasmodium infections were diagnosed by examination of thick blood smears and PCR. Stool samples 295 individuals (69%) were examined by direct smear and the Kato–Katz technique. The overall prevalence of malaria, intestinal protozoan infection, and intestinal helminth infection was 14.2%, 100%, and 39.3%, respectively. Polyparasitism was predominant (83.7%), and most infected individuals had at least two or more different species of intestinal protozoan and/or helminth parasites. The prevalence of co-infection was 49.5%, and in individuals with intestinal protozoa and helminth infections (34%), Entamoeba. coli, Entamoeba histolytica, and Ascaris lumbricoides were the most common parasites. In individuals with malaria and protozoa infections (10.2%), P. vivax, E. coli, and E. histolytica predominated, and in individuals with malaria, protozoa, and helminth infections (5.4%). P. vivax, E. coli, E. histolytica, and A. lumbricoides predominated. Intestinal polyparasitism was common in the study population, and the presence of helminths was associated with an increased number of intestinal parasitic species. However, Plasmodium infections were neither a risk nor a protective factor for helminth infections; the same was true for helminth infections in relation to Plasmodium. The high prevalence of intestinal polyparasitism with Plasmodium co-infections highlights the need for combining strategies that may help control both malaria and intestinal parasite and generate a health approach aligned with indigenous perspectives.

Targeting the nervous system of the parasitic worm, Haemonchus contortus with quercetin

Prevalence of infection, limited choice of drugs, and emerging resistance against contemporary medications lead to a pressing need to develop new anthelmintic drugs and drug targets. However, little understanding of worms' physiology has substantially delayed the process. Here, we are reporting the tissue morphology of Haemonchus contortus, intestinal parasitic helminths found in small ruminants, and targeting its nervous system with quercetin, a naturally occurring flavonoid. Quercetin showed anthelmintic activity against all of the developmental stages of H. contortus. Further, histological analysis demonstrated damage to various body parts, including isthmus, brut, pseudocoele, and other organs. Mechanistic studies revealed the generation of oxidative stress and alterations in the activities of the stress response enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase. Moreover, the time-dependent imaging of reactive oxygen species (ROS) generated due to quercetin treatment disclosed neuropils as the primary targets of quercetin in adult worms, which eventually lead to the paralysis and death of the worms. Thus, this work demonstrates that the nervous system of the parasitic helminth, H. contortus, is a novel target of the drug quercetin.

Protection from T cell-dependent colitis by the helminth-derived immunomodulatory mimic of transforming growth factor-β, Hp-TGM.

In animal models of inflammatory colitis, pathology can be ameliorated by several intestinal helminth parasites, including the mouse nematode Heligmosomoides polygyrus. To identify parasite products that may exert anti-inflammatory effects in vivo, we tested H. polygyrus excretory-secretory (HES) products, as well as a recombinantly expressed parasite protein, transforming growth factor mimic (TGM), that functionally mimics the mammalian immunomodulatory cytokine TGF-β. HES and TGM showed a degree of protection in dextran sodium sulphate-induced colitis, with a reduction in inflammatory cytokines, but did not fully block the development of pathology. HES also showed little benefit in a similar acute trinitrobenzene sulphonic acid-induced model. However, in a T cell transfer-mediated model with recombination activation gene (RAG)-deficient mice, HES-reduced disease scores if administered throughout the first 2 or 4 weeks following transfer but was less effective if treatment was delayed until 14 days after T cell transfer. Recombinant TGM similarly dampened colitis in RAG-deficient recipients of effector T cells, and was effective even if introduced only once symptoms had begun to be manifest. These results are a promising indication that TGM may replicate, and even surpass, the modulatory properties of native parasite HES.

Parasitic etiology of diarrhea and associated factors among under-five-year children attending Mizan-Tepi University Teaching Hospital, Southwest Ethiopia.

globally, an estimated two billion cases of diarrhea occur every year, and an estimated 1.7 million children under the age of five years, mostly in developing countries die due to diarrheal cases. It is caused by different enteropathogens such as bacteria, viruses, and parasites. Diarrhea caused by parasitic etiology is common in under-five-year children in sub-Saharan Africa. The objective was to investigate the parasitic etiology of diarrhea among under-five-year children in Mizan-Tepi University Teaching Hospital, Southwest Ethiopia. institution-based cross-sectional study was conducted from September to November 2021. A total of 300 under-five-year children presenting with diarrhea in Mizan-Tepi University Teaching Hospital were included in the study. Data used to assess associated factors for intestinal parasitic infections (IPIs) was collected using a structured questionnaire. Stool specimens were collected from the study participants for investigations of the parasitic etiology of diarrhea. The specimens were processed microscopically using direct wet mount and formol ether concentration techniques. Modified Ziehl-Neelsen staining of formol-ether concentrated specimens was also performed. Data was entered using Epi-Data version 4.6.0 and analyzed using Stata/SE version 14.0. Crude odds ratio and adjusted odds ratio were used to determine the association. from a total of 300 children who participated in this study, 68 (22.67%) were positive for at least one intestinal parasite. E. histolytica23(7.67%) and G. lamblia17(5.67%) were the predominant parasitic etiologies and 28(9.33%) were positive for intestinal helminthic parasites; 11(3.67%) Ascaris lumbricoides, 10(3.33%) Trichuris trichiura, 4(1.33%) Hymenolepsis nana, and 3(1%) were double infection with Trichuris trichuria and Ascaris lumbricoides. Multivariable analysis revealed the age group category 2-3 years of age children was more attributable to intestinal parasitic infections (AOR= 0.466, 95% CI: 0.204-0.976). the overall prevalence of intestinal parasitic infections (IPIs) in this study was 22.67%. Diarrheal etiology of intestinal parasites among under five years of children identified in this study were significantly associated with maternal/ guardians´ educational status, (AOR=94.900, 95% CI: 24.664-365.155) use of unprotected water for drinking, (AOR =25.189, 95% CI: 4.671-135.847).

Guts within guts: the microbiome of the intestinal helminth parasite Ascaris suum is derived but distinct from its host

BackgroundIntestinal helminths are extremely prevalent among humans and animals. In particular, intestinal roundworms affect more than 1 billion people around the globe and are a major issue in animal husbandry. These pathogens live in intimate contact with the host gut microbiota and harbor bacteria within their own intestines. Knowledge of the bacterial host microbiome at the site of infection is limited, and data on the parasite microbiome is, to the best of our knowledge, non-existent.ResultsThe intestinal microbiome of the natural parasite and zoonotic macropathogen, Ascaris suum was analyzed in contrast to the diversity and composition of the infected host gut. 16S sequencing of the parasite intestine and host intestinal compartments showed that the parasite gut has a significantly less diverse microbiome than its host, and the host gut exhibits a reduced microbiome diversity at the site of parasite infection in the jejunum. While the host’s microbiome composition at the site of infection significantly determines the microbiome composition of its parasite, microbial signatures differentiate the nematodes from their hosts as the Ascaris intestine supports the growth of microbes that are otherwise under-represented in the host gut.ConclusionOur data clearly indicate that a nematode infection reduces the microbiome diversity of the host gut, and that the nematode gut represents a selective bacterial niche harboring bacteria that are derived but distinct from the host gut.2jWY34QGXgkVDDF3YbbM2YVideo

Prevalence of Intestinal and Urinary Helminth Parasite Infections among ‎Residents of Communities around Lake Alau, Maiduguri

Intestinal and urinary helminth infections affect up to a quarter of the world’s population, with the potential of causing significant public health and economic burden. The occurrence of helminth parasites in stool and urine of residents, and water and soil samples of some communities around Lake Alau, Maiduguri, Nigeria was determined using direct microscopy, floatation and sedimentation techniques. A total of 349 (34.7%) residents were infected out of the 1,005 examined, consisting of 220 (21.9%) males and 129 (12.8%) females, with significant (p<0.05) variation based on gender. Similarly, the infection was significantly (p<0.05) higher among young individuals 197(19.6%) than the adults 152(15.1%). Among the ten communities (Logajiri, Melari, Dumbari, AlauLimanti, Awa Isari, Limanti, Gaskeri, Attakeri, Chellomi and Gomari Karekǝri) examined, the infection was significantly (p<0.05) highest at Gomari Karekǝri 57 (5.7%) and Alau Limanti 55(5.5%) and least at Gaskeri 19 (1.9%) and Chellomari 20 (2.0%). Intestinal parasites encountered consist of Ascaris lumbricoides 234 (23.3%), Trichuris trichiura 24 (2.4%), Strongyloides stercoralis 10 (1.0%), Schistosoma mansoni 8 (0.8%), and Taenia species 1 (0.1%) (p<0.05). Schistosoma haematobium 72 (7.2%) was the only helminth parasite recovered from urine samples examined. Environmental (water and soil) contamination with parasite stages was predominantly with pre-parasitic nematode larvae 50 (25%), eggs of Strongyloides stercoralis 50 (25%), Ascaris lumbricoides 30 (15%), Strongyle spp. 30 (15%) and cysts of protozoans; Entamoeba histolytica 30 (15%) and Giardia intestinalis 10 (5%). The results suggest that infection with intestinal and urinary parasites is common among the residents of the study area and that socio-cultural habits may favour the survival and transmission of these parasites in the area.

Length-Weight Relationship and the Distribution of Intestinal Helminth Parasites in Freshwater Fishes from Amansea and Ebenebe Rivers in Anambra State, Nigeria

Aims: The current study was carried out to evaluate the prevalence and distribution of intestinal helminths in freshwater fishes. 
 Study Design: The study was a survey done to establish the type of intestinal parasite found in freshwater fish in the rivers.
 Place and Duration of Study: The fish samples were collected from Amansea and Ebenebe Rivers from November 2021 to January 2022.
 Methodology: Intestinal parasites of three (3) fish species commonly found in these rivers (Parachanna obscura, Clarias gariepinus, and Ctenopoma kingsleyae) were examined. A comparative evaluation of the prevalence and distribution of the parasite was done in relation to their gender, location, weight, and length.
 Results: A total of 24 fish samples were collected in the Amansea River and 26 samples were collected in Ebenebe River. Seventeen (17) samples of P. obscura, 21 samples of C. gariepinus and 12 samples of C. kingsleyae caught with the cast nets of various mesh sizes and gill traps by artisanal fishermen in Rivers were bought early in the morning, transported to the Laboratory and identified based on morphological features. Out of a total of 50 fish sampled, 17 fishes (34% of the total sample) were infected by intestinal helminths. P. obscura had the highest parasite prevalence (47.06%) followed by C. gariepinus (42.86%). However, no parasite was recorded in C. kingsleyae. Prevalence of intestinal parasites in Ebenebe (18.00%) was higher than in Amansea (16.00) with a significant difference in prevalence (p<0.05), while parasite abundance was higher in Amansea (50.94%) than in Ebenebe (49.06%) with significant difference (p<0.05). Females had the highest prevalence (35.00%) against male fishes (33.33%) with no significant difference. A total number of 53 parasites belonging to 7 genera were recovered in this study. Parasites identified were nematodes: Procamallanus sp. (41.5%), Camallanus sp. (9.43%), Rhabdochona sp. (26.42%), Contracaecum sp. (7.55%), and Spinitectus sp. (5.66%); cestodes: Polyonchobothrium sp. (5.66%); and trematodes: Clinostomum sp (3.77%). The highest parasite abundance was recorded in Procamallanus sp. (41.5%), while Clinostomum sp had the least (3.77%).
 Conclusion: This study revealed that the prevalence of intestinal parasites in freshwater fish is relatively high. Therefore, fish consumers should subject the fish to proper processing before consumption as some of these parasites are of zoonotic importance.

Reconstructing the history of helminth prevalence in the UK.

Intestinal helminth parasites (worms) have afflicted humans throughout history and their eggs are readily detected in archaeological deposits including at locations where intestinal parasites are no longer considered endemic (e.g. the UK). Parasites provide valuable archaeological insights into historical health, sanitation, hygiene, dietary and culinary practices, as well as other factors. Differences in the prevalence of helminths over time may help us understand factors that affected the rate of infection of these parasites in past populations. While communal deposits often contain relatively high numbers of parasite eggs, these cannot be used to calculate prevalence rates, which are a key epidemiological measure of infection. The prevalence of intestinal helminths was investigated through time in England, based on analysis of 464 human burials from 17 sites, dating from the Prehistoric to Industrial periods. Eggs from two faecal-oral transmitted nematodes (Ascaris sp. and Trichuris sp.) and the food-derived cestodes (Taenia spp. and Diphyllobothrium latum syn Dibothriocephalus latus) were identified, although only Ascaris was detected at a high frequency. The changing prevalence of nematode infections can be attributed to changes in effective sanitation or other factors that affect these faecal-oral transmitted parasites and the presence of cestode infections reflect dietary and culinary preferences. These results indicate that the impact of helminth infections on past populations varied over time, and that some locations witnessed a dramatic reduction in parasite prevalence during the industrial era (18th-19th century), whereas other locations continued to experience high prevalence levels. The factors underlying these reductions and the variation in prevalence provide a key historical context for modern anthelmintic programs.

PARASITIC FAUNA OF MALAPTERURUS ELECTRICUS AND PARACHANNA OBSCURA FROM LEKKI LAGOON, LAGOS, NIGERIA

Host condition factor and gastrointestinal parasites in Malapterurus electricus and Parachanna obscura in Lekki lagoon, Lagos, Nigeria were investigated from September, 2014 to February, 2015. Eighty (80) fishes of Malapterurus electricus and eighty (80) of Parachanna obscura were caught and dissected for intestinal helminth parasites and protozoa. Condition factors of all individuals were determined. Median condition (K < 2.17 and K > 2.17) for Malapterurus electricus, (K < 1.02 and K > 1.02) for Parachanna obscura were used in grouping the individuals. Protozoa infection in the gut includes; myxosporidia and coccidians. Heterogeneous infection of these protozoa in low condition Parachanna obscura were; Myxosporidia, 0.20, Coccidia, 0.10 and high condition individuals, 0.10, 0.15 respectively. There were no coccidian infection in M. electricus, but myxosporidia in low and high condition individuals were 0.15 and 0.10. The rate of infection of Electrotaenia malopteruri, a cestode, specific to M. electricus was higher among high condition individuals, 0.15, compared low condition individuals, 0.10. Procamallanus sp, had the highest prevalence among the high condition individuals of Parachanna obscura, the trend was; High Condition M.electricus (0.10) < Low Condition P.obscura (0.15) < Low Condition M.electricus (0.20) < High Condition P.obscura (0.25). Infected individuals of low condition factor (K < 2.17) of Malapterurus electricus had a greater histopathological alteration index (HAI, 18.0) compared to the high condition individuals (HAI, 8.0). These individuals had from mild to severe ulceration of the mucosa and congestion of the blood vessels. In infected individuals of low condition factor (K < 1.02) of Parachanna obscura, there were mucosal edema and haemorrhage in their intestinal walls. They also had greater histopathological alteration index (HAI, 22.0) compared to the high condition individuals (HAI, 6.0). Prevalence of gastrointestinal parasitic fauna in low condition host could be an indicator of stress in fish

HOST RELATIVE CONDITION FACTOR AND THE PREVALENCE OF INTESTINAL PARASITES OF PARACHANNA OBSCURA AND SAROTHERODON MELANOTHERON AS INDICATORS OF ENVIRONMENTAL STRESS IN LEKKI LAGOON, LAGOS, NIGERIA

Condition factor is a measure of energetics, nutritional status and viability of a host. Changes in the host condition factor have effect on the rate of infection. 100 fishes of Sarotherodon melanotheron and 90 of Parachanna obscura from the Lekki lagoon were procured and dissected for intestinal helminth parasites. Condition factors of all individuals were determined. Median condition (K < 1.32 and K > 1.32) for Parachanna obscura and (K < 4.09 and K > 4.09) for Sarotherodon melanotheron were used in grouping the individuals. Male and female individuals of low condition factor (K < 1.32) and (K < 4.09) had very low parasite prevalence, 5.55% to 8.69% compared to male and female individuals of high condition (K > 1.32) and (K > 4.09), having a prevalence of 13.64% to 30.43%. These percentages were expressed in the various parasite groups in the population. The exception to these, were the female individuals of Sarotherodon melanotheron of low condition status (K = 3.93±0.11) that had a percentage prevalence of 35.71% for Clinostomum sp. These individuals had a more stable condition but compromised immunological status. Changes in the environment, both anthropogenic and environmental, can alter host/parasite equilibrium and cause disease or mortality in fish. The infected individuals of low condition status showed bile stasis within the liver parenchyma, under histopathological examination. Decrease or increase in parasite prevalence as a result of poor health condition of the host is an indicator of environmental stress. Monitoring health condition of fish population provides vital information for ecotoxicologist and toxicologist for improved environmental monitoring.