Parasite Co-infection Research Articles

Schistosoma mansoni co-infection modulates Chagas disease development but does not impair the effect of benznidazole-based chemotherapy

The adequate management of parasite co-infections represents a challenge that has not yet been overcome, especially considering that the pathological outcomes and responses to treatment are poorly understood. Thus, this study aimed to evaluate the impact of Schistosoma mansoni infection on the efficacy of benznidazole (BZN)-based chemotherapy in Trypanosoma cruzi co-infected mice. BALB/c mice were maintained uninfected or co-infected with S. mansoni and T. cruzi, and were untreated or treated with BZN. Body weight, mortality, parasitemia, cardiac parasitism, circulating cytokines (Th1/Th2/Th17); as well as heart, liver and intestine microstructure were analyzed. The parasitemia peak was five times higher and myocarditis was more severe in co-infected than T. cruzi-infected mice. After reaching peak, parasitemia was effectively controlled in co-infected animals. BZN successfully controlled parasitemia in both co-infected and T. cruzi-infected mice and improved body mass, cardiac parasitism, myocarditis and survival in co-infected mice. Co-infection dampened the typical cytokine response to either parasite, and BZN reduced anti-inflammatory cytokines in co-infected mice. Despite BZN normalizing splenomegaly and liver cellular infiltration, it exacerbated hepatomegaly in co-infected mice. Co-infection or BZN exerted no effect on hepatic granulomas, but increased pulmonary and intestinal granulomas. Marked granulomatous inflammation was identified in the small intestine of all schistosomiasis groups. Taken together, our findings indicate that BZN retains its therapeutic efficacy against T. cruzi infection even in the presence of S. mansoni co-infection, but with organ-specific repercussions, especially in the liver.

Parasitic coinfections among selected smallholder goat flocks in Malaysia.

This paper describes the occurrence of multiple parasitic infection with special reference to emerging haemotropic Mycoplasma ovis. A cross-sectional survey of four selected goat flocks was conducted to collect samples and management information. Blood samples were processed using microhaematocrit centrifugation to determine the packed cell volume (PCV). Detection and morphological identification of blood protozoa and haemotropic Mycoplasma ovis from Giemsa-stained smears were done microscopically. M. ovis infection was classified mild (1-29% infected cells), moderate (30-59% infected cells), or severe (above 60% infected cells). Faecal floatation and McMaster faecal egg count were used to detect and classify strongyle infections as negative (no eggs/oocysts), light (< 500 epg), Moderate (500 - 1000 epg), or severe (>1000 epg) and coccidia infection as light (<1800 opg), moderate (1800 - 6000 opg), or severe (>6000 opg). There were 149 goats with blood protozoa (57.98%; 95% CI: 51.87 - 63.85) and 204 goats with GI parasites (79.38%; 95% CI: 74.02 - 83.87) involved in single (15.8%; 95% CI: 11.7 - 21.0) or multiple (84.2%; 95% CI: 79.0 - 88.3) infections. The risk of Strongyles increases by 2.49 (95% CI: 1.24 - 4.99) in females versus males and 6.79 (95% CI: 3.25 - 14.18, p =0.000) in adults versus young. The risk of Eimeria species increases by 7.32 (95% CI: 3.45 - 15.50, p =0.000) in adults versus young, while M. ovis coinfection risk increases by 4.51 (95% CI: 1.40 - 14.50, p =0.000) in female versus males. Thin animals had a significantly higher (p<0.05) mean burden of Strongyle (1370.37 ± 345.49) and Eimeria (1594.12 ± 695.26) than the moderate and fat goats. The PCV was negatively associated with mean faecal egg count (FEC) (p<0.05) such that a lower PCV was recorded in animals with a higher Strongyle epg output. A severe burden of M. ovis was accompanied by an increased nematode FEC and decreased haematocrit (p<0.05). Coinfections of Strongyles, or Eimeria species involving M. ovis were associated with a higher parasitaemia compared with single infections (p<0.05). This study highlights the importance of M. ovis and Strongyle or Eimeria species coinfections among goat flocks and provides valuable data for developing and implementing an integrated herd health management program for parasite control among low-input smallholder flocks.

CO-INFECTION WITH MALARIA AND INTESTINAL PARASITES AND ITS ASSOCIATION WITH ANEMIA IN CHILDREN (ZERO TO TEN YEARS OLD) IN TIKO SUBDIVISION, CAMEROON.

Concomitant infections with malaria and intestinal parasitic infections may be associated with anemia in children (0-10 yr). This study determined the prevalence of co-infection with malaria and intestinal parasitic infections and determined its association with anemia in children (0-10 yr) in Tiko, Cameroon. A hospital-based cross-sectional study was carried out whereby venous blood and stool samples were collected from 377 febrile children. Blood was used to perform a full blood count. Thick and thin blood films were prepared and stained with Giemsa for malaria parasite diagnosis. The formol ether concentration technique was used to analyze the stools. Pearson's chi-square test, Student's t-test, and other statistical analyses were performed. Of the 377 participants, 139 (36.9%) were positive for malaria, 21 (5.6%) had intestinal helminths, 8 (2%) had co-infection, and 79 (21.0%) were anemic. Malaria and anemia were prevalent among the children and were significantly associated (P = 0.025). There was no statistically significant difference (P > 0.05) among age groups. Girls were more often infected with malaria (69, 37.3%), and boys were more often infected with intestinal parasites (13, 7.0%), but there was no statistical association for both malaria and intestinal parasitic infections (IPIs) for both sexes (P > 0.05). Hookworms, Ascaris lumbricoides, and Trichuris trichiura were the intestinal parasites found in this study. There was a significant association between anemia and parasitic co-infection in children (P = 0.003). Malaria and IPIs are prevalent in the Tiko municipality. They play a great role in anemia especially when there is a co-infection. Public education and awareness campaigns are necessary in this municipality.

Parasite Fauna and Coinfections in Urban Rats Naturally Infected by the Zoonotic Parasite Angiostrongylus cantonensis.

When the zoonotic parasite of rodents that can cause human neuroangiostrongyliasis, i.e., Angiostrongylus cantonensis, is found in its natural definitive hosts, it is usually reported in isolation, as if the rat lungworm were the only component of its parasite community. In this study, we report the coinfections found in rats naturally infected by A. cantonensis in urban populations of Rattus norvegicus and Rattus rattus in Valencia, Spain. In addition to the rat lungworms, which were found in 14 of the 125 rats studied (a prevalence of 11.20%), 18 other parasite species (intestinal and tissular protists, microsporidia and helminths) were found, some of them with high burdens. Fourteen of these nineteen species found are potential zoonotic parasites, namely Blastocystis, Giardia duodenalis, Cryptosporidium spp., Enterocytozoon bieneusi, Encephalitozoon hellem, Toxoplasma gondii, Brachylaima spp., Hydatigera taeniaeformis s.l. larvae, Hymenolepis nana, Hymenolepis diminuta, Angiostrongylus cantonensis, Calodium hepaticum, Gongylonema neoplasticum and Moniliformis moniliformis. The total predominance of coinfected rats as well as their high parasite loads seem to indicate a trend towards parasite tolerance.

Is co-infection of intestinal parasites with COVID-19 virus infection affecting its severity?

Is co-infection of intestinal parasites with COVID-19 virus infection affecting its severity?

Occurrence of Hepatozoon in Some Reptiles from Brazilian Biomes with Molecular and Morphological Characterization of Hepatozoon caimani

Amphibians and reptiles represent a considerable proportion of the vertebrate fauna in Brazil. Different blood parasitic infections have been reported in these groups, such as Haemogregarina, Hepatozoon, Trypanosoma and microfilariae. However, insufficient research on interactions between these parasites and their hosts has been carried out in some regions of the country. Samples were collected from populations of wild herpetofauna in different microhabitats throughout Brazil, totaling 111 samples of reptiles from the states of Mato Grosso and Pernambuco. We used an integrative approach, with classical microscopy, morphometry and molecular analysis, in order to identify hemoparasites present in the analyzed fauna. Genomic DNA was extracted for the PCR protocol based on the 18S ribosomal RNA gene for Hepatozoon spp. A total of 53 positives were obtained with molecular screening (47.7%), all confirmed as Hepatozoon spp. using DNA sequencing. Among positive samples, 23 slides were examined, confirming the presence of Hepatozoon spp. in 91.3% of the smears. The phylogenetic analysis performed with sequences from 43 samples resulted in a tree containing several distinct clades. Sequences were generally grouped according to the taxonomic order of the host. Co-infections with microfilariae and Trypanosoma spp. were also found in microscopy analyses. This study describes the presence of Hepatozoon caimani in a new host species (Paleosuchus palpebrosus) that can be a paratenic host in the natural environment. The existence of parasitic co-infections in alligator species underscores the significance of recognizing the impact of infections by various parasitic taxa on the host populations.

Severe Parasite Co-Infection in a Captive Bactrian Camel: Case Report

The aim of this study was to document a case of parasite co-infection in a captive Bactrian camel and to supply morphometric data of the found pathogens. It concerned a 20-year-old male animal inhabiting Sofia Zoo, Bulgaria. A decreased appetite and gastrointestinal disorders were observed in it during the summer of 2022. Improvement in the animal’s condition was achieved after the administration of antibiotics, sulfonamides, and other symptomatic medicines. However, two weeks after treatment, clinical symptoms reappeared. Then, a diarrheal fecal sample from the animal was subjected to parasitological examination by direct smear and flotation and sedimentation techniques. Multiple infections by helminths (Trichostrongylus sp., Haemonchus sp., Oesophagostomum sp., Trichuris sp., and Dicrocoelium sp.), ciliates (Buxtonella cameli), and protozoa (Eimeria cameli) were found, with E. cameli being reported for the first time in zoo conditions. Deworming led to the recovery of the general condition and appearance of the animal’s feces, but two weeks later, it died suddenly. We considered that the parasitic infection was not the direct cause of the fatal outcome, and its presence, other health disorders, and the advanced age of the animal were among the contributing factors. This case reveals the need to combine planned preventive deworming with routine parasitological diagnostics to take timely and targeted actions to protect the health of animals inhabiting zoo facilities.

Coinfection of the gut with protozoal and metazoal parasites in broiler and laying chickens

The chicken business faces substantial economic losses due to the risk of parasitic coinfection. Because the current study aimed to investigate enteric parasitic coinfections problems among the suspected examined chicken farms, samples were collected during the field investigation from suspected freshly dead birds, clinically diseased, apparently healthy, and litter samples for further laboratory parasitological, histopathological, and immunological examinations. Variable mortalities with various clinical indicators, such as ruffled feathers, weight loss, diarrhea of various colors, and a decline in egg production, occurred on the farms under investigation. In addition, the treatment protocols of each of the farms that were evaluated were documented and the m-RNA levels of some cytokines and apoptotic genes among the infected poultry have been assessed. The prevalence rate of parasitic coinfection in the current study was found to be 8/120 (6.66%). Parasitological analysis of the samples revealed that they belonged to distinct species of Eimeria, cestodes, and Ascaridia galli. When deposited, A. galli eggs were nonembryonated and ellipsoidal, but cestodes eggs possessed a thin, translucent membrane that was subspherical. Eimeria spp. oocysts in layer chickens were identified as Eimeria acervulina and Eimeria maxima in broiler chickens. Our findings proved that coinfection significantly upregulated the IL-1β, BAX, and Cas-3 genes. Conversely, the IL-10, BCL-2, and AKT mRNA levels were downregulated, indicating that nematode triggered apoptosis. The existence of parasite coinfection was verified by histological investigation of the various intestinal segments obtained from affected flocks. A. galli and cestodes obstructed the intestinal lumen, causing different histological alternations in the intestinal mucosa. Additionally, the lamina propria revealed different developmental stages of Eimeria spp. It was determined that parasite coinfection poses a significant risk to the poultry industry. It was recommended that stringent sanitary measures management methods, together with appropriate treatment and preventative procedures, be employed in order to resolve such issues.

Preexisting helminth challenge exacerbates infection and reactivation of gammaherpesvirus in tissue resident macrophages.

Even though gammaherpesvirus and parasitic infections are endemic in parts of the world, there is a lack of understanding about the outcome of coinfection. In humans, coinfections usually occur sequentially, with fluctuating order and timing in different hosts. However, experimental studies in mice generally do not address the variables of order and timing of coinfections. We sought to examine the variable of coinfection order in a system of gammaherpesvirus-helminth coinfection. Our previous work demonstrated that infection with the intestinal parasite, Heligmosomoides polygyrus, induced transient reactivation from latency of murine gammaherpesvirus-68 (MHV68). In this report, we reverse the order of coinfection, infecting with H. polygyrus first, followed by MHV68, and examined the effects of preexisting parasite infection on MHV68 acute and latent infection. We found that preexisting parasite infection increased the propensity of MHV68 to reactivate from latency. However, when we examined the mechanism for reactivation, we found that preexisting parasite infection increased the ability of MHV68 to reactivate in a vitamin A dependent manner, a distinct mechanism to what we found previously with parasite-induced reactivation after latency establishment. We determined that H. polygyrus infection increased both acute and latent MHV68 infection in a population of tissue resident macrophages, called large peritoneal macrophages. We demonstrate that this population of macrophages and vitamin A are required for increased acute and latent infection during parasite coinfection.

Co-infection of Plasmodium falciparum and Schistosoma mansoni is associated with anaemia

BackgroundMalaria and schistosomiasis persist as major public health challenge in sub-Saharan Africa. These infections have independently and also in polyparasitic infection been implicated in anaemia and nutritional deficiencies. This study aimed at assessing asymptomatic malaria, intestinal Schistosoma infections and the risk of anaemia among school children in the Tono irrigation area in the Kassena Nankana East Municipal (KNEM) in the Upper East Region of Northern Ghana.MethodsA cross sectional survey of 326 school children was conducted in the KNEM. Kato Katz technique was used to detect Schistosoma eggs in stool. Finger-prick capillary blood sample was used for the estimation of haemoglobin (Hb) concentration and blood smear for malaria parasite detection by microscopy.ResultsThe average age and Hb concentration were 10.9 years (standard deviation, SD: ± 2.29) and 11.2 g/dl (SD: ± 1.39) respectively with 58.9% (n = 192) being females. The overall prevalence of infection with any of the parasites (single or coinfection) was 49.4% (n = 161, 95% confidence interval, CI [44.0–54.8]). The prevalence of malaria parasite species or Schistosoma mansoni was 32.0% (n = 104) and 25.2% (n = 82), respectively with 7.7% (n = 25) coinfection. The prevalence of anaemia in the cohort was 40.5% (95%CI [35.3–45.9]), of which 44.4% harboured at least one of the parasites. The prevalence of anaemia in malaria parasite spp or S. mansoni mono-infections was 41.8% and 38.6%, respectively and 64.0% in coinfections. There was no statistically significant difference in the odds of being anaemic in mono-infection with malaria (OR = 1.22, 95% CI 0.71–2.11, p = 0.47) or S. mansoni (OR = 1.07, 95% CI 0.58–1.99, p = 0.83) compared to those with no infection. However, the odds of being anaemic and coinfected with malaria parasite species and S. mansoni was 3.03 times higher compared to those with no infection (OR = 3.03, 95% CI 1.26–7.28, p = 0.013).ConclusionThe data show a high burden of malaria, S. mansoni infection and anaemia among school children in the irrigation communities. The risk of anaemia was exacerbated by coinfections with malaria parasite(s) and S. mansoni. Targeted integrated interventions are recommended in this focal area of KNEM.

Simultaneous quantitative determination of residues of abamectin, ivermectin, albendazole and its three metabolites in beef and chicken by HPLC-PDA.

Antimicrobial drugs are frequently used in a combination or shuttle way to cope with coinfection of bacteria or parasites and prevent drug resistance, thus the accurate quantification of multiple drug residues in animal-derived foods is crucial to ensure food safety. Here, a simple and efficient high-performance liquid chromatography-photodiode array (HPLC-PDA) method was established for the simultaneous quantitative screening of six common residues of antiparasitic drugs, including abamectin (ABM), ivermectin (IVM), albendazole (ABZ) and the three metabolites of ABZ in beef and chicken. The LODs and LOQs for six target compounds in beef and chicken are determined to be 3.2 to 12.5µg/kg and 9.0 to 30.0µg/kg, respectively. The calibration curves show good linearity (R2≥0.9990) between the peak area and concentration. The recoveries from the fortified blank samples are all above 85.10%. Finally, the applicability of the HPLC-PDA method is successfully demonstrated by the real sample analysis.

Magnitude and predisposing factors of intestinal parasitosis and tuberculosis coinfection at five health institutions in Southern Ethiopia: A cross-sectional study.

Intestinal parasites affect the tuberculosis disease outcome by shifting the cell-mediated to humoral immune response and host immune system suppression. However, Mycobacterium tuberculosis (MTB) infection favors the immune escape of parasites. Hence, exploring the rate of intestinal parasitic coinfection with pulmonary tuberculosis (PTB) and its predisposing factors to take better preventive, control, and management measures. A facility-based cross-sectional study was conducted from September to December 2020 at five health institutions in Hawassa city. A total of 214 PTB patients were diagnosed using the GeneXpert assay and enrolled in this study. Demographic, clinical, and risk factors data were collected using a structured questionnaire. Stool samples were collected using a clean, labeled, and leak-proof stool cup. Stool samples were examined using direct saline microscopy and the formal-ether concentration technique. The data were entered and coded in SPSS software for analysis. Bivariate and multivariate logistic regression were employed to identify the associated risk factors. A p-value less than 0.05 was considered statistically significant. The overall rate of intestinal parasitic-MTB coinfection was 36.9%. The most dominant intestinal parasite was Gardia lamblia (17.8%, 38), followed by Entamoeba histolytica/dispar (9.3%, 20). Intestinal parasitosis coinfection of PTB was associated with being rural resident (adjusted odds ratio [AOR] = 2.42; 95% confidence interval [CI]: 1.23-4.8), not washing of fruits and vegetables before eating [AOR = 4.14; 95% CI: 1.92-9], being at the early stage of anti-TB treatment [AOR = 3; 95% CI: 1.5-6.3] and presence of chronic diseases [AOR = 7; 95% CI: 3.4-14]. The burden of intestinal parasites-MTB coinfection was high. Those who wash fruits and vegetables before eating should be encouraged, early treatment of PTB patients and avoiding the practice of open-field defecation, especially in rural communities, is necessary. The dual effect of coinfection on disease severity and treatment success needs further cohort study.

Co-parasitism in the face of predation: Effects of natural enemies on a neotropical mockingbird.

Co-parasitism is ubiquitous and has important consequences for the ecology and evolution of wild host populations. Studies of parasite co-infections remain limited in scope, with few experimental tests of the fitness consequences of multiple parasites, especially in natural populations. We measured the separate and combined effects of Philornis seguyi nest flies and shiny cowbirds Molothrus bonariensis on the fitness of a shared host, the chalk-browed mockingbird (Mimus saturninus) in Argentina. Using a two-factor experimental approach, we manipulated the presence of nest flies and cowbirds in mockingbird nests and assessed their effects on mockingbird haemoglobin levels, begging and provisioning rates, body size, and fledging success. We also monitored rates of nest predation in relation to parasitism by flies and cowbirds. Nest flies reduced the haemoglobin concentration, body size, and fledging success of mockingbirds, likely because mockingbirds did not compensate for parasitism by begging more or feeding their nestlings more. Cowbirds also reduced the fledging success of mockingbirds, even though they had no detectable effect on haemoglobin or body size. Nests with cowbirds, which beg more than mockingbirds, attracted more nest predators. There was no significant interaction between the effects of flies and cowbirds on any component of mockingbird fitness. The combined effects of nest flies and cowbirds were strictly additive. In summary, we show that nest flies and cowbirds both reduce host fitness, but do not have interactive effects in co-parasitized nests. Our results further suggest that predators exacerbate the effects of nest flies and cowbirds on their hosts. Our study shows that the fitness consequences of co-parasitism are complex, especially in the context of community-level interactions.

Knowledge, Attitudes and Practices Among Adult Malaria Patients Co-Infected with Opportunistic Intestinal Coccidian Parasites in Fundong Health District, Northwest, Cameroon: A Cross Section Study Design

Introduction: Malaria and intestinal coccidian parasitic co-infections, are becoming a public health emergency affecting millions of people around the world. They are among the leading cause of socio-economic problems, long suffering and death especially in developing countries like Cameroon. Introducing new appropriate preventive and control measures to the population requires thorough assessment of community and patient-based knowledge, attitude and preventive practices towards malaria and pathogenic intestinal coccidian parasites is crucial. Our study aimed to describe knowledge, attitudes, and practices and the risk factors among adult malaria patients co-infected with intestinal parasitic infections in the Fundong Health District, a locality in the Northwest Region of Cameroon. Methods: This was a cross-sectional study carried out between February and December, 2022 involving sixteen (16) health facilities in Fundong Health district. A total number of 330 patients participated in the study. Normal saline wet mount and formol-ether concentration techniques were employed in coccidian parasitic detection. Blood samples were subjected to Giemsa stained and viewed microscopically to detect the Plasmodium parasites. Pretested structured questionnaires were administered to collect information on patient’s socio-demographic factors and determine patients’ knowledge, attitudes and practices towards malaria and intestinal coccidian parasites, as well as their prevention and control. The Pearson’s Chi-Square (χ2) and Student T-test were performed a part of the statistical analysis to check for associations between malaria, infection and between malaria-coccidian co-infection and demographic factors. Statistical significance was set a P-value&lt;0.05. Results: Participants main sources of information on malaria were: Television (TV) and radio 111/330 (34%), community health workers 109/330 (33%), and Hospitals (37%). Participants had good knowledge of mosquito bite as the malaria transmission route, 296/330 (90%), night time is the frequent biting time for the mosquito 296/330(90%), dark corners 229 (69%) and dirty areas 175(53%) as mosquito resting places. Knowledge score was also good on cleaning of the house surroundings, 281/330(85%), clearing the bushes 180/330(55%), poor knowledge score on drainage of stagnant water113/330 (34%) as ways to prevent the mosquito from multiplying. Participants had good knowledge of insecticide treated bed nets 295/330 (89%) as the best way to prevent mosquito bites. However, participants also expressed poor knowledge on edges of the river or streams 7(20%), and animal shed 20/330 (6%) as mosquito hiding places, and Plasmodium specie as malaria causative agent 8/330 (2%) (P-value=0.011). Poor scores were recorded on knowledge of opportunistic intestinal coccidian parasites (19.4%) (P=0.427), and was significantly low on unsafe water (47.2%) (P-value=0.036) as possible transmission routes for coccidian parasites. The knowledge score was also low on the at-risk population for malaria and intestinal coccidian infection (31.9%) P-value=0.009. Participants who had poor knowledge about coccidian transmission routes were less likely to drink from protected water source with an odds of 0.713(95% CI: 0.297-1.711) P value=0.449, compared to those who were more knowledgeable and who were 2.981(95% CI: 1.367-6.115) P value=0.005, more likely to use protected source of drinking water. Participants who had hand washing facility in the household were 3.488 (1.760-6.912) value=0.001 times more likely have better knowledge of coccidian transmission routes compared to those who did not have 0.748 (95% CI: 0.406-1.376) P value=0.350. Poor knowledge score of poor hygiene as major cause of coccidian infection significantly associated with poor practice score of sometime or not at all disinfecting animal shed to prevent coccidian infection among study participants (P =0.039). Conclusion: The overall knowledge scores, attitude and practices level of participants towards malaria and opportunistic intestinal coccidian parasites were relatively good. A significant proportion of the participants still have misconceptions about cause, modes of transmission and practices towards malaria and coccidian prevention methods. A combined health education programmes for malaria and intestinal coccidian parasites aimed at raising community awareness needs to be evidence based and requires innovative approaches, to address the gaps identified in the study.

SURVEY ON THE MOST COMMON DISEASES CIRCULATING AMONG PIGEONS IN THE EASTERN PROVINCE, SAUDI ARABIA

Molecular and microbiological approaches were used to investigate the common circulating pathogens in pigeon flocks. Sixty-nine flocks were investigated for viral, bacterial and parasitic infection evidence, including the histories, clinical signs and lesions. We reported that the seroprevalences of Newcastle disease viruses (NDVs), Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) were 50.57%, 7.25% and 8.69%. respectively; no avian influenza virus (AIV)‒specific antibodies were detected. NDVs and pigeon paramyxoviruses (PPVs) were detected in 40.57% and 15.9%, respectively, of the pigeons. Multiple diseases were the predominant finding, with 60.87% of diseased flocks harboring multifactorial infections of viral, bacterial and parasitic pathogens. Concurrent viral and bacterial infections were reported in 15.94%, and viral and parasitic coinfections were found in 20.29%. Mixed infections of NDV with bacterial and parasitic diseases were detected in 21.74%. Bacterial and mycotic pathogens were detected in 22/69 (31.88%) and 5/69 (7.25%), respectively. Salmonella spp. were only detected in 3/69 (4.35%) of diseased flocks. Parasitic diseases were the most prevalent infections, either as a single infection or concurrently with others. Parasites including Cestoda spp., Ascaris spp., Eimeria spp., Trichomonas gallinae and external parasites(Menopon gallinae, Pseudolynchia canariensis) were reported in 12/69 (17.39%), 10/69 (10.49%), 10/69 (10.49%), 18/69 (26.1%) and 3/69 (4.35%), respectively. We concluded that pigeon flocks harbor many pathogens that may threaten the health of animals and humans; they are serious amplifiers and reservoir hosts of disease and, ultimately, may be serious biological hazards to the intensive poultry production sector and community. Pigeon vaccines should be developed. Strict biosecurity measures should be applied to protect pigeons and commercial poultry flocks. Key words: Pigeon, diseases, PCR, isolation and identification, Saudi Arabia

Dynamics of co-infection in fish: A review of pathogen-host interaction and clinical outcome

Co-infections can affect the transmission of a pathogen within a population and the pathogen's virulence, ultimately affecting the disease's dynamics. In addition, co-infections can potentially affect the host's immunological responses, clinical outcomes, survival, and disease control efficacy. Co-infections significantly impact fish production and can change several fish diseases’ progression and severity. However, the effect of co-infection has only recently garnered limited attention in aquatic animals such as fish, and there is currently a dearth of studies on this topic. This study, therefore, presents an in-depth summary of the dynamics of co-infection in fish. This study reviewed the co-infection of fish pathogens, the interaction of pathogens and fish, clinical outcomes and impacts on fish immune responses, and fish survival. Most studies described the prevalence of co-infections in fish, with various parameters influencing their outcomes. Bacterial co-infection increased fish mortality, ulcerative dermatitis, and intestinal haemorrhage. Viral co-infection resulted in osmoregulatory effects, increased mortality and cytopathic effect (CPE). More severe histological alterations and clinical symptoms were related to the co-infection of fish than in single-infected fish. In parasitic co-infection, there was increased mortality, high kidney swelling index, and severe necrotic alterations in the kidney, liver, and spleen. In other cases, there were more severe kidney lesions, cartilage destruction and displacement. There was a dearth of information on mitigating co-infections in fish. Therefore, further studies on the mitigation strategies of co-infections in fish will provide valuable insights into this research area. Also, more research on the immunology of co-infection specific to each fish pathogen class (bacteria, viruses, fungi, and parasites) is imperative. The findings from such studies would provide valuable information on the relationship between fish immune systems and targeted responses.

Comparative histopathology of livers from Baltic cod infected with the parasitic nematode Contracaecum osculatum

Infection levels with the parasitic nematode Contracaecum osculatum in Eastern Baltic cod have increased in the last decades. Eastern Baltic cod is transport host for this parasite that has a high affinity for the liver of the fish. The liver is a highly vital organ and damage to the liver tissue can result in reduced functionality of the organ. Previous studies have revealed that cod with high infections loads reveal impaired physiological performance, reduced nutritional condition and show signs of having a liver disease. Yet, little is known about the pathological changes and inflammatory reactions of the cod liver related to the infections. In this study, we performed histological examinations on 30 Baltic cod livers caught in the eastern part of the Baltic Sea (length; 38 ± 0.9cm, weight; 454 ± 34.8gram) and three Sound cod livers (length; 63 ± 2.9cm, weight; 3396 ± 300.2gram) to categorize the degree of inflammation and its relation to pathological changes in infected cod livers. We further investigated how C.osculatum infection levels varied with intensity of inflammation and co-infections. We found that high infection loads with C.osculatum caused severe inflammation in the liver tissue of cod and reduced fat content of the hepatocytes. Conspicuous amounts of glycogen were found in the muscle and intestinal epithelial cells of the nematodes and parasitic co-infections occurred more frequently in the most heavily infected livers.

A review of tuberculosis and parasitic disease co-infection in ungulates, with regard to the potential threat to European bison (Bison bonasus).

Bovine tuberculosis (BTB) is a dangerous zoonosis which presents a serious problem for endangered species such as European bison ( Bison bonasus). Little is known about the influence of parasitic co-infections on the course and diagnosis of tuberculosis in animals. The best known co-infection in cattle is Fasciola hepatica and Mycobacterium bovis. The aim of this study was to review the most recent literature regarding tuberculosis and parasite co-infection in ungulates and relate the results to European bison. Our findings indicate that any comprehensive diagnosis of BTB should include parasitological monitoring, and the possible impact of such invasions on cellular response-based tuberculosis tests should be taken into account. The diagnosis of BTB is complex, as is its pathogenesis, and parasitic infestations can have a significant impact on both. This should be taken into account during further research and monitoring of tuberculosis in European bison.

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.

Coinfection rates of avian blood parasites increase with latitude in parapatric host species.

Animals are frequently coinfected with multiple parasites concurrently, and advances in our sampling of these complex intra-host parasite communities have revealed important ecological impacts on their hosts. However, the spatial distributions and environmental determinants of parasite coinfection remain infrequently studied. Here, we investigated the drivers of haemosporidian blood parasite coinfection in the Bicknell's thrush (Catharus bicknelli) and grey-cheeked thrush (Catharus minimus), parapatric sister species that occur across a broad latitudinal range in northern North America. Using 298 samples from across the distributions of these species, we found high overall infection (86%) and coinfection (41%) rates within host populations. Coinfection rates within populations were highly variable across sampling sites, ranging from 7 to 75%. Latitude was a more important predictor of coinfection frequency than host species identity, with coinfections becoming more abundant at higher latitudes. The 2 host species exhibited similar parasite faunas, and an analysis of the co-occurrence patterns among haemosporidians showed that host species identity was largely not a factor in structuring which parasites were found within coinfections. To our knowledge, this is the first study to illustrate a reverse latitudinal gradient in coinfection frequency in a eukaryotic parasite system. Further work is necessary to determine whether vector ecology or some other factor is the primary proximate driver of this pattern.