Seasonal Variation In Prevalence Research Articles

Molecular phylogenetic analysis and seasonal dynamics of Eimeria species infecting broilers of Kashmir, India.

Globally, the poultry industry is seriously threatened by coccidiosis caused by various species of Eimeria. This protozoan parasite inhabits the epithelial lining of the gastrointestinal tract of poultry globally and can cause serious clinical disease. The present study was carried out on poultry farms located in various regions of Kashmir, India, to investigate the prevalence and phylogenetic relationships of Eimeria species affecting broiler chickens. Over a period of one year, fecal samples were collected from 60 poultry farms in Kashmir and morphological and molecular techniques were employed for Eimeria species identification. Results revealed a high prevalence of coccidiosis, with 58.3% (35/60) of farms positive for Eimeria. The most prevalent species were E. tenella (31/35, 88.6%) followed by E. acervulina (25/35, 71.4%), E. maxima (19/35, 54.3%), E. mitis (18/35, 51.4%), and E. necatrix (9/35, 25.7%). Seasonal variation in prevalence was also observed, with the highest rates in autumn (86.7%) and summer (66.7%). Additionally, younger birds (3-4weeks) exhibited higher infection rates (85.7%) compared to older birds (57.9%) (5-6weeks). Mixed infection was found in 94.2% (33/35) of positive farms. Phylogenetic analysis using ITS1 sequences confirmed species clustering and revealed evolutionary relationships among Eimeria species. E. tenella and E. necatrix formed a distinct clade, while E. acervulina formed another. The study underscores the importance of molecular techniques in accurate species identification and provides valuable insights into the epidemiology of coccidiosis in poultry in Kashmir. Effective control strategies, including vaccination and improved management practices, are necessary to mitigate the economic losses associated with this widespread poultry disease.

Seasonal Variation in Detection of Haemosporidia in a Bird Community: A Comparison of Nested PCR and Microscopy.

In a 2-yr study on prevalence of Haemosporidia in an avian community in Ithaca, New York, USA, we tested the hypothesis that apparent seasonal variation in prevalence is influenced by the detection protocol. We confirmed a higher detection of Haemosporidia using a molecular diagnosis technique (PCR) than by microscopy; this further increased when the PCR test was triplicated. Microscopic examination and PCR techniques have different specificity and sensitivity and therefore different probabilities of detecting hemoparasites. Birds with chronic infections or sampled during winter often have very low parasitemia, and such infections may be missed by microscopy but detected by PCR. Haemosporidian prevalence was higher during the breeding season than during the nonbreeding season regardless of the method used. Detection of Leucocytozoon spp. infection from blood smears using microscopy was challenging.

Prevalence and seasonal aspects of parasitism by Oestrus ovis (Diptera: Oestridae) in sheep from Mato Grosso State, Brazil.

Oestrus ovis larvae are obligate parasites of vertebrates and cause cavitary myiasis (oestrosis) in sheep and goats. It is also reported as a zoonosis causing ophthalmomyiasis and nasopharyngeal myiasis. Despite being relatively common in Brazil, epidemiological studies on O. ovis are scarce. Considering that the infestation is influenced by the climate and biomes of the studied region, we aimed to investigate the seasonal prevalence of O. ovis among slaughtered sheep in the northern region of the state of Mato Grosso, Brazil. The heads of sheep (n=697) slaughtered at a slaughterhouse in the municipality of Terra Nova do Norte (November 2011 to November 2013) were collected to count, catalog, and identify the larvae found in the upper respiratory tract. Overall, 45.77% (319/697) of the animals were infested with 2,412 recovered larvae, 96.89% (2,337/2,412) of which were identified at the species level as O. ovis. Seasonal variations in prevalence ranged from 41% (spring) to 56% (summer); however, no correlation was observed between prevalence and season, mean humidity, or temperature. In conclusion, parasitism by O. ovis in sheep in the studied area, occurs year-round, considering the occurrence of larvae (L1, L2, and L3) throughout the year, probably because of the area's environmental conditions.

Seasonal Variation and Factors Affecting Trypanosoma theileri Infection in Wild Sika Deer (Ezo Sika Deer Cervus nippon yesoensis) in Eastern Hokkaido.

Trypanosoma (Megatrypanum) spp. are isolated from domestic and wild ruminants, including deer, worldwide. The prevalence of trypanosomes in mammals is influenced by a number of factors such as host age and vector abundance. However, the seasonal variation of and factors affecting trypanosome infection in the wild deer population remain elusive. In this study, we analyzed the seasonal variation in trypanosome prevalence and the factors that affect Trypanosoma theileri Laveran, 1902, infection in wild sika deer (Ezo sika deer) Cervus nippon yesoensis (Heude, 1884) in Eastern Hokkaido through a two-year survey. Seasonal variation in the prevalence of trypanosome infection in the deer population ranged from 0 to 41% as per hematocrit concentration and 17 to 89% as per PCR results. In general, the prevalence of T. theileri by PCR in 2020 was higher than that in 2019. Moreover, the prevalence was significantly higher in the aged population than among the younger population. These findings may explain why individual conditions and sampling season were associated with trypanosome prevalence. This is the first study to investigate the seasonal variation in and risk factors affecting trypanosome infection in wild deer.

Foodborne protozoan parasites in fresh mussels and oysters purchased at retail in Canada

Studies worldwide have reported the presence of protozoan parasites in a variety of commercial bivalve shellfish. The uptake of these parasites by shellfish occurs during filter feeding in faecally-contaminated waters. The objective of the present study was to determine the prevalence of Giardia, Cryptosporidium and Toxoplasma in fresh, live shellfish purchased in three Canadian provinces as part of the retail surveillance activities led by FoodNet Canada (Public Health Agency of Canada). Packages containing mussels (n = 253) or oysters (n = 130) were purchased at grocery stores in FoodNet Canada sentinel sites on a biweekly basis throughout 2018 and 2019, and shipped in coolers to Health Canada for testing. A small number of packages were not tested due to insufficient quantity or poor quality. Following DNA extraction from homogenized, pooled tissues, nested PCR and DNA sequencing were used to detect parasite-specific sequences. Epifluorescence microscopy was used to confirm the presence of intact cysts and oocysts in sequence-confirmed PCR-positive samples. Giardia duodenalis DNA was present in 2.4 % of 247 packages of mussels and 4.0 % of 125 packages of oysters, while Cryptosporidium parvum DNA was present in 5.3 % of 247 packages of mussels and 7.2 % of 125 packages of oysters. Toxoplasma gondii DNA was only found in mussels in 2018 (1.6 % of 249 packages). Parasite DNA was detected in shellfish purchased in all three Canadian provinces sampled, and there was no apparent seasonal variation in prevalence. While the present study did not test for viability, parasites are known to survive for long periods in the marine environment, and these findings suggest that there is a risk of infection, especially when shellfish are consumed raw.

New host–parasite associations of Cymothoidae (Crustacea, Isopoda) infesting elasmobranch fishes in Tunisian waters

Between 2015 and 2020, 2 092 specimens of cartilaginous fishes (Chondrichthyes: Elasmobranchii) belonging to eight species and five genera were sampled along the Tunisian coast and examined for their cymothoid parasites, Among the eight examined elasmobranch species, only three were infested, Five parasite species were identified: Anilocra physodes, Emetha audouini, Ceratothoa oestroides, C. parallela and Nerocila orbignyi, These parasites presented three maturation stages: ovigerous females of A.physodes and E. audouini, adult non-ovigerous females of N. orbignyi, and juvenile females of C. oestroides and C. parallela, Most of these parasitic isopods were found on a single host species except for the two Ceratothoa species. We report new host-parasite associations, including the presence of A. physodes and E.audouini on smooth-hound Mustelus mustelus, the occurrence of C. oestroides and N. orbignyi on cartilaginous fish species, and the presence of C. parallela on black smooth-hound Mustelus punctulatus and M. mustelus. Parasitological indices and the seasonal variation in prevalence of the collected cymothoids, as well as parasitic species richness, are presented.

Seasonal Variation in Prevalence of Mycoplasma hyopneumoniae and Other Respiratory Pathogens in Peri-Weaned, Post-Weaned, and Fattening Pigs with Clinical Signs of Respiratory Diseases in Belgian and Dutch Pig Herds, Using a Tracheobronchial Swab Sampling Technique, and Their Associations with Local Weather Conditions.

Besides Mycoplasma hyopneumoniae (M. hyopneumoniae), many other viruses and bacteria can concurrently be present in pigs. These pathogens can provoke clinical signs, known as porcine respiratory disease complex (PRDC). A sampling technique on live animals, namely tracheobronchial swab (TBS) sampling, was applied to detect different PRDC pathogens in pigs using PCR. The objective was to determine prevalence of different PRDC pathogens and their variations during different seasons, including correlations with local weather conditions. A total of 974 pig farms and 22,266 pigs were sampled using TBS over a 5-year period. TBS samples were analyzed using mPCR and results were categorized and analyzed according to the season of sampling and local weather data. In samples of peri-weaned and post-weaned piglets, influenza A virus in swine (IAV-S), porcine reproductive and respiratory syndrome virus—European strain (PRRSV1), and M. hyopneumoniae were found as predominant pathogens. In fattening pigs, M. hyopneumoniae, porcine circovirus type 2 (PCV-2) and PRRSV1 were predominant pathogens. Pathogen prevalence in post-weaned and finishing pigs was highest during winter, except for IAV-S and A. pleuropneumoniae, which were more prevalent during autumn. Associations between prevalence of several PRDC pathogens, i.e., M. hyopneumoniae, PCV-2 and PRRSV, and specific weather conditions could be demonstrated. In conclusion, the present study showed that many respiratory pathogens are present during the peri-weaning, post-weaning, and fattening periods, which may complicate the clinical picture of respiratory diseases. Interactions between PRDC pathogens and local weather conditions over the 5-year study period were demonstrated.

SEASONAL VARIATION OF MASKED UNCONTROLLED NOCTURNAL HYPERTENSION MEASURED BY NIGHTIME HOME BLOOD PRESSURE: THE J-HOP NOCTURNAL BLOOD PRESSURE STUDY

Objective: Usual daytime (morning and evening) home blood pressure (BP) monitoring can not detect nighttime hypertension. Masked uncontrolled nocturnal hypertension is defined as uncontrolled nighttime BP nonetheless controlled usual daytime home BP (HBP). Although previous studies have reported seasonal variation of nighttime BP evaluated by ambulatory BP monitoring is higher in summer than winter, seasonal variation in prevalence of masked uncontrolled nocturnal hypertension evaluated by nighttime HBP measurements remains unclear. Hence, we assessed the seasonal variation in nighttime HBP and the prevalence of masked uncontrolled nocturnal hypertension using a dataset of the Japan Morning Home-Surge BP (J-HOP) Nocturnal BP study. Design and method: This is a cross-sectional, post-hoc analysis using the dataset of the J-HOP Nocturnal BP study, which recruited patients with a history of or risk factors of cardiovascular disease. Participants underwent consecutive 14-day HBP measurements (morning and evening) and nighttime HBP measurements (a.m. 2, 3, and 4). We divided participants into four groups in each season. Masked uncontrolled nocturnal hypertension was defined as controlled daytime HBP (mean of morning and evening home systolic BP [SBP] < 135 mmHg and diastolic BP [DBP] < 85 mmHg) and uncontrolled nocturnal HBP (mean nighttime home SBP >= 120 or DBP >= 70 mmHg). Results: Among 2545 participants (age, 63.3 ± 10.3 yrs; 49% of male; antihypertensive medication use, 82.6%), 629, 596, 719, and 601 participants were enrolled in spring, summer, autumn, and winter, respectively. Nighttime home SBP/DBP were higher in summer than winter (SBP/DBP in summer, 123.3 ± 14.6/70.4 ± 8.9 mmHg; vs. in winter, 119.3 ± 14.0/69.1 ± 8.4 mmHg, p < 0.05). In 1490 participants with controlled daytime HBP, moreover, the prevalence of masked uncontrolled nocturnal hypertension was higher in summer than other seasons (summer, 55.7% vs. spring, 41.8%; vs. autumn, 42.9%; vs. winter, 39.7%, all p < 0.01). These relationships were also observed in multivariate logistic regression analysis (Table). Conclusions: In the present study, we revealed the prevalence of masked uncontrolled nocturnal hypertension was higher in summer than other seasons.

Seasonal dynamics of haemosporidian (Apicomplexa, Haemosporida) parasites in house sparrows Passer domesticus at four European sites: comparison between lineages and the importance of screening methods

Infectious diseases often vary seasonally in a predictable manner, and seasonality may be responsible for geographical differences in prevalence. In temperate regions, vector-borne parasites such as malaria are expected to evolve lower virulence and a time-varying strategy to invest more in transmission when vectors are available. A previous model of seasonal variation of avian malaria described a double peak in prevalence of Plasmodium parasites in multiple hosts resulting from spring relapses and transmission to susceptible individuals in summer. However, this model was rejected by a study describing different patterns of seasonal variation of two Plasmodium spp. at the same site, with the double peak only apparent when these species were combined. Here, we assessed the seasonal variation in prevalence of haemosporidian parasites (Plasmodium, Haemoproteus and Leucocytozoon) in house sparrows (Passer domesticus) sampled across 1 year at four temperate European sites spanning a latitudinal range of 17°. We showed that parasite prevalence and diversity decreased with increasing latitude, but the parasite communities differed between sites, with only one Plasmodium lineage (P_SGS1) occurring at all sites. Moreover, the nested PCR method commonly used to detect and identify haemosporidian parasites strongly underestimated co-infections of Haemoproteus and Plasmodium, significantly biasing the pattern of seasonal variation, so additional molecular methods were used. Finally, we showed that: (i) seasonal variation in prevalence of haemosporidian parasites varied between study sites and parasite lineages/species/genera, describing further cases where the double peak model is not met; (ii) the seasonal dynamics of single lineages (P_SGS1) varied between sites; and (iii) unexpectedly, seasonality was greatest at the southernmost site, a pattern that was mostly driven by lineage H_PADOM05. Limitations of the genotyping methods and consequences of pooling (parasite lineages, sites and years) in studies of haemosporidian parasites are discussed and recommendations proposed, since these actions may obscure the patterns of prevalence and limit ecological inferences.

Morphology, seasonality and molecular characterization of Ceratomyxa draconis n. sp. parasite of Trachinus draco (L.) from the Bay of Bizerte, Tunisia.

The specimens of Trachinus draco collected from the Bay of Bizerte were found to be infected with a new Ceratomyxa species described as Ceratomyxa draconis n. sp. The sequence of small subunit ribosomal RNA gene obtained in this study differs from other Ceratomyxa sequences available in GenBank. Mature spores of this species were elongated and crescent-shaped in sutural view, measuring 7.4 ± 0.77 (6.4-8.0) μm in thickness and 30.8 ± 1.65 (28.8-32.8) μm in width. The polar capsules were spherical, equal in size, and measuring 3.3 ± 0.2 (3.6-4.0) μm in diameter. The Ceratomyxa draconis n. sp. showed a clearly seasonal variation of prevalence with highest prevalence noted during summer months.

SEASONAL VARIATION IN PREVALENCE OF MASKED UNCONTROLLED HYPERTENSION IN GENERAL PRACTICE OUTPATIENTS

Objective: Masked hypertension is generally known as a cardiovascular disease (CVD) risk factor at a same level comparable to sustained hypertension. However, there is no data on seasonal differences in the prevalence of masked hypertension in outpatients under hypertensive treatment in clinical practice. We thus assessed seasonal variation in prevalence of masked uncontrolled hypertension using dataset of the Japan Morning Surge-Home Blood Pressure (J-HOP) study. Design and method: The J-HOP study is a nation-wide prospective observational study to predict CVD events in clinical practice outpatients, and participants underwent home blood pressure (BP) measurements in the morning and evening for a 14-day period. Clinic and home BP levels, prevalence of masked uncontrolled hypertension were compared in participants divided by seasons when they measured HBP. Masked uncontrolled hypertension was defined as clinic BP < 140/90 mmHg and morning or evening home BP > 135/85 mmHg based on the current Japanese guideline. Results: Among 4271 participants (mean age, 64.9 ± 10.9 years; 47.0% male; 91.4% hypertensive patients, 67 institutions in various areas in Japan), morning home systolic BP was significantly lower in summer compared to other seasons (spring, 139.4 ± 15.5 mmHg; summer, 134.1 ± 15.6 mmHg; autumn, 139.4 ± 16.1 mmHg; winter, 140.3 ± 15.5 mmHg, p value < 0.01 in all comparison between summer and other seasons). Moreover, prevalence of masked uncontrolled hypertension was significantly higher in winter that that in summer (spring, 22.5%; summer, 18.1%; autumn, 22.7%; winter, 24.4%, p < 0.01 in comparison between summer and winter) (Figure). In multivariate logistic regression analysis, masked uncontrolled hypertension was lower in summer compared to spring as reference after adjusted host factors and clinic BP levels (odds ratio, 0.60; 95% confidence interval, 0.47 to 0.77, p < 0.001).Conclusions: The present study revealed prevalence of masked uncontrolled hypertension tended to be lower in summer. Measurement of home BP is thus more valuable than clinic BP for management of hypertension corresponding to changes of season.

Co-infection with tick-borne disease agents in cattle in Russia

Tick-borne diseases cause significant livestock losses worldwide. In Russia, information concerning single or mixed infections with different Anaplasma, Theileria and Babesia species in cattle is very limited. This study was conducted to determine the level of co-infection with protozoan pathogens (Theileria spp. and Babesia spp.) and rickettsial pathogens (A. marginale and A. phagocytophilum) in cattle in central Russia. Blood samples were examined with real time polymerase chain reaction (RT-PCR) for A. marginale and A. phagocytophilum, and by amplifying the V4 hypervariable region of the 18S rRNA gene, followed by cloning, DNA sequencing, and phylogenetic analyses, for Babesia and Theileria species. In total 67% of examined blood samples were positive for Theileria spp. or A. marginale, and 19% of the animals were co-infected with Theileria spp. and A. marginale. Seasonal variation in prevalence was found for Theileria spp. Phylogenetic analysis based on 18S rRNA gene sequences revealed the presence of five Theileria species: T. annulata, T. orientalis, T. buffeli, T. sergenti, and T. sinensis. No samples were positive for Babesia spp. or A. phagocytophilum. The data obtained for prevalence of bovine theileriosis and anaplasmosis in the central part of Russia underscore the need for improved surveillance and control programs to reduce tick-borne diseases in cattle.

Prevalence of haemoprotozoan diseases in cattle of Cauvery delta region of Tamil Nadu.

A study was carried out to determine the prevalence of haemoparasites in cattle in Cauvery delta region over a period of one year. A total of 228 giemsa stained blood smears were screened for the presence of haemoprotozoa, out of which 34 animals were found to be positive. An overall prevalence of haemoparasites in the sampled cattle were 14.9%, among this Anaplasma sp (8.3%), Babesia sp (3.95%), Theileria sp (2.19%) and Trypanosoma sp (0.44%) as single or mixed blood parasiticinfections. In this study Anaplasmosis (14%) was highly prevalent during the winter season and Babesiosis (13.73%) was highly prevalent during summer months followed by Anaplasmosis (9.8%) and Theileriosis (7.8%), the lowest prevalence of Trypanosomiasis was observed during the rainy season. The seasonal variation in prevalence of haemoprotozoan disease might be due to influence of climatic factors on density of vector population in that geographical area. Haemogram revealed decreased level of haemoglobulin, packed cell volume and total erythrocyte count. The serum biochemistry revealed elevated level of liver enzyme Asparate transaminase enzyme. All haemoparasitaemic animals were treated with specific drugs and recovered successfully.

Seasonal variation in prevalence, parasite load and mean intensity of ectoparasites in Pipistrellus kuhlii (Chiroptera: Vespertilionidae) from Iran

We studied quantitatively the seasonal variation in prevalence, parasite load, and mean intensity of two species of ectoparasites in free ranging populations of Kuhl's bat, Pipistrellus kuhlii in western Iran. In total, 348 live bats (230 males and 118 females) were collected using mist net during May to November 2013. All bats identified as to sex and the number of ectoparasite species in each bat was counted. On 348 P. kuhlii captured, 5355 ectoparasites were observed. Two species of ectoparasites belonging to Argas vespertilionis (Argasidae) and Steatonyssus sp. (Macronyssidae) were identified. In late May and at the beginning of June, the peaks of ectoparasite load in bats were recorded and then dropped during June to November. The number of ectoparasites in pregnant female bats in May-June during pregnancy was significantly higher than non-pregnant females (p ≤ 0.05). A significant correlation was found between ectoparasite load and the ratio of body mass to the length of forearm (W/FA), as an index of body condition, indicating that parasite load has apparent impact on bat’s health. Our findings indicated that parasite loads correlate with season, sex and reproductive condition of the host.

First identification of Naegleria species and Vahlkampfia ciguana in Nile water, Cairo, Egypt: Seasonal morphology and phylogenetic analysis.

In Egypt, there is a scarcity of data concerning Naegleria (N.) family, with a shortage of phylogenetic studies. This study's aim was molecular detection, sequencing and phylogenetic analysis of morphologically identified Nagleria and to determine natural seasonal distribution of Nagleria species in water sources of Greater Cairo, Egypt. A total of 120 water samples were collected during each season over a year. Every water sample was filtrated and cultured on non-nutrient agar (NNA). Morphologically positive Nagleria-like isolates were subjected to Nagleria genus and species-specific PCR targeting rDNA gene, PCR products were sequenced and obtained sequences were phylogenetic analyzed. Nile River water was the only source found to contained Naegleria. For the first time in Egypt, Vahlkampfia ciguana and the Naegleria species N.australiensis, N.philippinensis and N.neojejuensis were identified from the Nile water. The pathogenic Naegleria fowleri, previously reported in Egypt, was however not detected in this study. Interestingly, there were no seasonal variations in prevalence of Naegleria spp.; yet, there was seasonal diversity in the water samples of the same site. These newly discovered Vahlkampfiidae in Egyptian aquatic environments indicate the need for further phylogenetic investigations using bigger sample sizes in order to determine their potential risk for human health.

Seasonal variations of exposure to agricultural pesticides in residents proximate to vineyards: SIGEXPOSOME study

Introduction The impact of environmental exposure to pesticides from agricultural drift on human health is a major public health concern. The International Agency for Research on Cancer (IARC) has classified several pesticides as carcinogenic or probable carcinogenic to humans. Residential proximity to treated farmland is a source of environmental pesticide exposure and has been associated with increased concentrations of pesticides in residential dust and urine samples. Little is known on the seasonal variations of pesticide concentrations. The SIGEXPOSOME project aims to investigate seasonal variations of the exposure to multiple agricultural pesticides of residents proximate to vineyards and of pesticide applicators in the Beaujolais area of the Auvergne-Rhone-Alpes Region, France. The study is based on a longitudinal study involving overall 185 subjects, with repeated sampling of multiple matrices (residential dust, urine, blood and hair). We report here preliminary results on 19 residents. Methods We sampled morning urine and household dust in 19 non-smoking, men, aged 18 to 65 years, without professional pesticides use, residing in the study area. Sampling was performed in July and October 2015. House dust: We used the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method for extraction and analytical multi-residue methods based on gas chromatography coupled to mass spectrometry (GC–MS) and liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). After analyses of the efficiency and repeatability of the analytical methods for 62 compounds, 53 pesticides were retained for analyses [recovery rate 70–120%; relative standard error (RSD) Results House dust: 40 pesticides out of 53 were quantified, including 11 compounds of high public health priority. Among pesticides with a detection frequency > 70% for at least one of the two sampling periods, we observed significant seasonal variations in prevalence for 10 pesticides (out of 18) and significant differences in concentrations for 14 pesticides: Chlorpyriphos, Cyprodinil, Difenoconazole, DimetomorpheI, DimetomorpheII, Fludioxynil, Indoxacarbe, Kresoxim-methyl, Myclobutanil, SpiroxamineI, SpiroxamineII, Tebuconazole, Trifloxystrobin and Zoxamide with an average concentration higher in July than in October. Urine samples: The LC-HRMS analyses showed the presence of three pesticides metabolites: 3,5,6-trichloro-2-pyridinol (TCPy), a specific metabolite of the organophosphate insecticides chlorpyrifos and chlorpyrifos-methyl; 3-phenoxybenzoic acid (3-PBA), a nonspecific metabolite of the pyrethroid insecticides permethrin, cypermethrin or cyhalothrin; hydroxy- and carboxy-metabolites of tebuconazole. The identity of TCPy and 3-BPA was confirmed by comparison with authentic standards. Conclusion This study, analyzing the seasonal variations of multiple pesticides, is unique in France. House dust of non-professional residents proximate to vineyards showed seasonal variations with higher prevalence and concentrations of agricultural pesticides during the application period. Also, results show the capacity of our screening approach based on LC-HRMS to detect agricultural compounds present at low concentrations in urine. Correlation between residential dust and urine contamination will be further explored as well as association between concentrations of pesticides in house dust and urine, and proximity to treated vineyards, a surrogate for pesticides drift. Funding Auvergne-Rhone-Alpes Region; Metropole Lyon; Canceropole CLARA.

Seasonal variations in Plasmodium falciparum parasite prevalence assessed by varying diagnostic tests in asymptomatic children in southern Ghana.

Plasmodium falciparum infections presenting either as symptomatic or asymptomatic may contain sexual stage parasites (gametocytes) that are crucial to malaria transmission. In this study, the prevalence of microscopic and submicroscopic asexual and gametocyte parasite stages were assessed in asymptomatic children from two communities in southern Ghana. Eighty children aged twelve years and below, none of whom exhibited signs of clinical malaria living in Obom and Cape Coast were sampled twice, one during the rainy (July 2015) and subsequently during the dry (January 2016) season. Venous blood was used to prepare thick and thin blood smears, spot a rapid malaria diagnostic test (PfHRP2 RDT) as well as prepare filter paper blood spots. Blood cell pellets were preserved in Trizol for RNA extraction. Polymerase chain reaction (PCR) and semi-quantitative real time reverse transcriptase PCR (qRT-PCR) were used to determine submicroscopic parasite prevalence. In both sites 87% (95% CI: 78–96) of the asymptomatic individuals surveyed were parasites positive during the 6 month study period. The prevalence of asexual and gametocyte stage parasites in the rainy season were both significantly higher in Obom than in Cape Coast (P < 0.001). Submicroscopic gametocyte prevalence was highest in the rainy season in Obom but in the dry season in Cape Coast. Parasite prevalence determined by PCR was similar to that determined by qRT-PCR in Obom but significantly lower than that determined by qRT-PCR in Cape Coast. Communities with varying parasite prevalence exhibit seasonal variations in the prevalence of gametocyte carriers. Submicroscopic asymptomatic parasite and gametocyte carriage is very high in southern Ghana, even during the dry season in communities with low microscopic parasite prevalence and likely to be missed during national surveillance exercises.

Variation in seasonal prevalence and intensity of progenetic metacercariae of Clinostomum complanatum infection in Trichogaster fasciatus fish

A total of 1242 out of 1484 Trichogaster fasciatus fish were found to be infected with metacercarial stage of Clinostomum complanatum where 14,258 parasites were recorded mainly from the peritoneal cavity, gills and viscera during five years of study period. The seasonal variations in prevalence, intensity and abundance of the parasitic infection were assessed. The maximum and minimum values of prevalence of metacercarial infection of C. complanatum in the fish were 92.40% and 70.40% during summer and winter respectively. Similarly, intensity and abundance of the parasite were maximum during summer as compared to winter and rainy seasons. The high prevalence of infection of the parasite during summer may be because of the time of emergence of cercariae in high temperature from snail vector and the environment.

Seasonal variation in prevalence of gastrointestinal helminthoses in cattle of New Alluvial zone of West Bengal, India

Gastrointestinal parasitism is one of the major constraints for profitable livestock production. The present study was conducted to determine the prevalence and seasonal variation in gastrointestinal helminthic infections in cattle of New Alluvial zone of West Bengal. A total 2520 faecal samples of cattle were collected from five different places of NAZ of West Bengal during the study period i.e. March 2014 to February 2015. The faecal samples were examined by standard sedimentation and floatation technique. The overall prevalence of gastrointestinal parasites was recorded as 55.71% in cattle of NAZ and Paramphistome (40.64%) was recorded as the predominant parasite followed by Strongyle group of nematodes (8.25%) and Fasciola (3.33%). Moniezia was the only cestode parasite recorded with an overall prevalence of 1.97%. Statistically significant (p < 0.05) variation was observed in the prevalence of gastrointestinal helminths among the various seasons. Monsoon season has significantly (p < 0.05) higher prevalence of gastrointestinal helminthes (64.28%) followed by winter (57.14%) and lowest in summer (45.24%). Prevalence of Paramphistome (47.62%) and Strongyle (9.52) were also significantly (p < 0.05) higher monsoon compared to other seasons. The epidemiological knowledge/information gathered in the present study would be exploited for evolving strategic control method against gastrointestinal parasitic infections in cattle.

Detection, prevalence, and transmission of avian hematozoa in waterfowl at the Arctic/sub-Arctic interface: co-infections, viral interactions, and sources of variation.

BackgroundThe epidemiology of avian hematozoa at high latitudes is still not well understood, particularly in sub-Arctic and Arctic habitats, where information is limited regarding seasonality and range of transmission, co-infection dynamics with parasitic and viral agents, and possible fitness consequences of infection. Such information is important as climate warming may lead to northward expansion of hematozoa with unknown consequences to northern-breeding avian taxa, particularly populations that may be previously unexposed to blood parasites.MethodsWe used molecular methods to screen blood samples and cloacal/oropharyngeal swabs collected from 1347 ducks of five species during May-August 2010, in interior Alaska, for the presence of hematozoa, Influenza A Virus (IAV), and IAV antibodies. Using models to account for imperfect detection of parasites, we estimated seasonal variation in prevalence of three parasite genera (Haemoproteus, Plasmodium, Leucocytozoon) and investigated how co-infection with parasites and viruses were related to the probability of infection.ResultsWe detected parasites from each hematozoan genus in adult and juvenile ducks of all species sampled. Seasonal patterns in detection and prevalence varied by parasite genus and species, age, and sex of duck hosts. The probabilities of infection for Haemoproteus and Leucocytozoon parasites were strongly positively correlated, but hematozoa infection was not correlated with IAV infection or serostatus. The probability of Haemoproteus infection was negatively related to body condition in juvenile ducks; relationships between Leucocytozoon infection and body condition varied among host species.ConclusionsWe present prevalence estimates for Haemoproteus, Leucocytozoon, and Plasmodium infections in waterfowl at the interface of the sub-Arctic and Arctic and provide evidence for local transmission of all three parasite genera. Variation in prevalence and molecular detection of hematozoa parasites in wild ducks is influenced by seasonal timing and a number of host traits. A positive correlation in co-infection of Leucocytozoon and Haemoproteus suggests that infection probability by parasites in one or both genera is enhanced by infection with the other, or that encounter rates of hosts and genus-specific vectors are correlated. Using size-adjusted mass as an index of host condition, we did not find evidence for strong deleterious consequences of hematozoa infection in wild ducks.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1666-3) contains supplementary material, which is available to authorized users.