Standard selection treatments with sulfadiazine limit Plasmodium yoelii host-to-vector transmission

Some early antimalarial drugs have been repurposed for experimental applications, thus extending their utility well beyond the point when resistance becomes prevalent in circulating parasite populations. One such drug is sulfadiazine, which is an analog of p-aminobenzoic acid (pABA), and acts as a competitive inhibitor of dihydropteroate synthase, which is an essential enzyme in the parasite's folate synthesis pathway that is required for DNA synthesis. Sulfadiazine treatment of mice infected with P. yoelii and P. berghei is routinely used to enrich for gametocytes by killing asexual blood stage parasites, but it is not well known if the exposed gametocytes are perturbed or if there is a detrimental effect on transmission. To determine if there was a significant effect of sulfadiazine exposure upon host-to-vector transmission, we transmitted Plasmodium yoelii (17XNL strain) parasites to Anopheles stephensi mosquitoes and evaluated the prevalence of infection (percent of mosquitoes infected) and intensity of infection (number of oocysts per infected mosquito) under different sulfadiazine treatment conditions of the mouse or of the mosquitoes. We observed that parasites exposed to sulfadiazine either in the mouse host or in the mosquito vector had a reduction in both the number of mosquitoes that became infected and in the intensity of infection compared to untreated controls. We also observed that provision of freshly prepared pABA in the mosquito sugar water could only marginally overcome the defects caused by sulfadiazine treatment. In contrast, we determined that gametocytes exposed to sulfadiazine were able to be fertilized and develop into morphologically mature ookinetes in vitro, and thus that sulfadiazine exposure in the host may be reversible if the drug is washed out and the parasites are supplemented with pABA in the culture media. Overall, this indicates that sulfadiazine dampens host-to-vector transmission, and that this inhibition can only be partially overcome by exposure to fresh pABA in vivo and in vitro. Because gametocytes are of great interest for developing transmission blocking interventions, we recommend that less disruptive approaches for gametocyte enrichment be used in order to study minimally perturbed parasites.

First Record of Pseudocapillaria tomentosa (Dujardin, 1845) Moravec, 1987 in Cultured Grass Carp in Basrah Province, Iraq

A total of 110 specimens of cultured grass carp Ctenopharyngodon idella (Pisces: Cyprinidae) were collected from three different fish pond stations in Basrah province, during the period from March till July 2007. Postmortem parasitological examinations indicated infection of the grass carp with the nematode Pseudocapillaria tomentosa and this infection occurred only in Faddak fish ponds during all months of investigation. The maximum incidence of infection was 26.6% in April, while the maximum intensity of infection was 8.5 in June. The present finding of this nematodes represents its first record in Iraqi fishes.

Failure of Repeated MDA with Albendazole for Trichuriasis Control in Schoolchildren of the Yangon Region, Myanmar

Soil-transmitted helminth (STH) infections are still a considerable challenge in Myanmar. We undertook a control program for STH infections (especially Trichuris trichiura) among schoolchildren in Myanmar using mass drug administration (MDA) and health education. Around 1,700 schoolchildren from 15 primary schools in 3 suburban districts (Shwe Pyi Thar, Twantay, and Kyauktan) of the Yangon Region were subjected in this study during 2017-2019. All of the schoolchildren in each school were orally administered albendazole (400 mg in a single dose) 2, 3, and 4 times a year in 2017, 2018, and 2019, respectively. The results revealed that the egg positive rate of any intestinal helminths (including STH) was reduced from 37.6% (649/1,724) in 2017 to 22.8% (352/1,542) in 2019. The egg positive rate of Ascaris lumbricoides was decreased remarkably from 23.3% (402/1,724) in 2017 to 3.6% (56/1,542) in 2019. However, that of T. trichiura was only slightly reduced from 26.9% (464/1,724) in 2017 to 20.2% (312/1,542) in 2019. The intensity of infection with A. lumbricoides and T. trichiura was both more or less reduced, and the proportion of light infection cases with A. lumbricoides and T. trichiura increased from 35.6% in 2017 to 64.3% in 2019 and from 70.3% in 2017 to 81.7% in 2019, respectively. The results indicated that repeated MDAs (2-4 times a year for 3 years) using albendazole on schoolchildren in Myanmar failed to control T. trichiura infection. For a successful control of trichuriasis in Myanmar, new MDA strategies, using a modified albendazole regimen (multiple daily doses for 2 or 3 days) or an alternative anthelmintic drug, such as oxantel pamoate, is strongly recommended.

Gender-related differences in prevalence, intensity and associated risk factors of Schistosoma infections in Africa: A systematic review and meta-analysis

Background Schistosomiasis remains a global-health problem with over 90% of its burden concentrated in Africa. Field studies reflect the complex ways in which socio-cultural and socio-economic variables, affect the distribution of Schistosoma infections across different populations. This review set out to systematically investigate and quantify the differences in Schistosoma infection burdens between males and females in Africa for two of the most prevalent Schistosoma species—Schistosoma mansoni and Schistosoma haematobium. Methodology We searched (from inception to 11th March 2020) Embase, MEDLINE, PubMed, and Web of Science for relevant studies on schistosomiasis. We included studies that report S. mansoni and/or S. haematobium prevalence and/or intensity data distributed between males and females. We conducted meta-analyses on the male to female (M:F) prevalence of infection ratios. Subgroup analyses were performed according to study baseline prevalence, sample size and the lower and upper age limit of study participants. We also present a descriptive analysis of differential risk and intensity of infection across males and females. Evidence for differences in the prevalence of schistosomiasis infection between males and females is presented, stratified by Schistosoma species. Result We identified 128 relevant studies, with over 200,000 participants across 23 countries. Of all the reported differences in the prevalence of infection between males and females, only 41% and 34% were statistically significant for S. mansoni and S. haematobium, respectively. Similar proportions of studies (27% and 34% for for S. haematobium and S. mansoni, respectively) of the reported differences in intensity of infection between males and females were statistically significant. The meta-analyses summarized a higher prevalence of infection in males; pooled random-effects weighted M:F prevalence of infection ratios were 1.20 (95% CI 1.11–1.29) for S. haematobium and 1.15 (95% CI 1.08–1.22) for S. mansoni. However, females are underrespresented in some of the studies. Additionally, there was significant heterogeneity across studies (Higgins I2 statistic (p-values < 0.001, I2values>95%)). Results of the subgroup analysis showed that the baseline prevalence influenced the M:F prevalence ratios for S. haematobium and S. mansoni, with higher M:F prevalence of infection ratios in settings with a lower baseline prevalence of infection. Across the studies, we identified four major risk factors associated with infection rates: occupational and recreational water contact, knowledge, socio-economic factors and demographic factors. The effect of these risk factors on the burden of infection in males and females varied across studies. Conclusions We find evidence of differences in prevalence of infection between males and females which may reflect differences in gender norms and water contact activities, suggesting that policy changes at the regional level may help ameliorate gender-related disparities in schistosomiasis infection burden. Collecting, robustly analysing, and reporting, sex-disaggregated epidemiological data, is currently lacking, but would be highly informative for planning effective treatment programmes and establishing those most at risk of schistosomiasis infections.

Study of haemoflagellates Trypanosoma sp. infection in some fish of Iraq marshes and relationship of leukocytes with inflammatory response

Fresh water fishes infected with different species of genus Trypanosoma parasite that is similar to that same genus in blood of mammals. Trypanosomiasis or sleeping sickness disease that causes by protozoa flagellate parasites which live inside cell called Trypanosoma. Fish parasites play an important role in regulating the population of their hosts. This study was implemented to verify the infection with Trypanosoma sp. report the cellular intervening through inflammatory response in blood smears of infected fishes. A total of 190 fishes of three species Carasobarbus luteus, Aspius vorax and Liza abu were collected from Al-Hamare and Al-Chibayish marsh south of Iraq. The flagellate parasite Trypanosoma sp. observed in blood of Carasobarbus luteus 41.42% and Aspius vorax 12.28% fishes, while no infection was recorded with Trypanosoma sp. in Liza abu fishes. Prevalence and mean intensity of infection were calculated. The different counts and various types of inflammatory cells were monitored, there are increased in lymphocytes in the infected fishes. Statistically, there are significant differences (p<0.05) among species of infected fish with Trypanosoma sp.

Endoparasite infestation of Indian Muntjac (Muntiacus muntjak) in Citra Pesona Ladangku Animal Park, North Sumatra

An investigation on the infestation by endoparasites in the fecal samples of Indian Muntjac (Muntiacus muntjak) captived at Citra Pesona Ladangku Animal Park, North Sumatera, Indonesia had been conducted from October to November 2020. The study aimed to determine the endoparasite species, prevalence, and intensity of the infestation. Fecal samples were prepared for microscopical examination using glass bead sedimentation method. Based the observation on 9 deers, three species of endoparasites were found namely Ascaris sp, Haemonchus sp and Paramphistomum sp. Observations in the first week revealed the prevalence of each species from often (Ascaris sp, Haemonchus sp) to common (Paramphistomum sp) with light (Haemonchus sp, Paramphistomum sp) to moderate (Ascaris sp). Observations in the second week only revealed the presence of Paramphistomum with often prevalency and light intensity of infection.

Fauna of parasite of cyprinids and percoids in the reservoirs of the Moscow Canal

The purpose of the research is determination of the species composition of parasites of cyprinid and percoid fish in the reservoirs of the Moscow Canal.Materials and methods. In 2019–2020, parasitological material was collected in the spring, summer and autumn from percoid (the pike perch and European perch) and cyprinid fish (the bream, silver bream, roach, rudd and sabrefish) aged 2 to 7 years from the reservoirs of the Moscow Canal (Ikshinsky, Pestovsky, Pyalovsky and Klyazminsky Reservoirs) by the methods generally accepted in ichthyo-parasitology. To quantify the fish infection rate, we used the incidence or prevalence of infection, the intensity of infection, and the mean amplitude of the intensity of infection. We used Kabiosh index (K) to assess the species diversity of parasites. Results and discussion. The parasitological analysis results of percoids and cyprinids from the reservoirs of the Moscow Canal are presented. 34 parasite species were found in fish, which belong to nine taxonomic groups: Microsporidia, Myxosporea, Monogenea, Cestoda, Trematoda, Nematoda, Acanthocephala, Hirudinea, Crustacea. The largest number of species belongs to trematodes, the rest, taxa (mixo- and microsporidia, cestodes, nematodes, acanthocephalans, leeches and parasitic crustaceans), are represented singly. We calculated the species diversity ratio (R) of fish parasites in the reservoirs, which ranged from 0.335 to 0.575, which indicates the fauna similarity from 50 to 75%. The greatest similarity in the parasite fauna was found in the roach (R = 0.168–0.447), the least in the European perch (R = 0.447–1.0). We have identified the dominant species that are found in more than 20% of the studied fish and determine the “core” of the parasitic fauna, which included 4 parasite species of epizootic and 1 parasite species of epidemiological significance.

RATE OF INFECTION OF DOMESTIC CHICKENS WITH HELMINTHS IN DIFFERENT CLIMATIC ZONES OF AZERBAIJAN

Within the framework of these studies during 2014-2015, the levels of extensiveness and intensity of infection by various types of helminths were studied for three age groups of chickens from local breeds, reared in outdoor stabling conditions and walking areas of family poultry farms in mountainous (Khizi district), foothill (Khachmaz district) and lowland (Saatly district) territories. In studies carried out in these three climatic zones, intense infection of birds with helminths at 3-4 months of age, making uo withA.galli EI 62.3, H. gallinarum EI 50.8, II 1-30, R.tetragona IE 36, 6, 1-14, S.trachea EI 29.1, C.obsignata EI 17.7 %, II 1-13, in 5-7 months of age Sinqamus II 1-19, in adults Askaridia II 1-36, were recorded in foothill areas. A low level of extensiveness and intensity of invasion of infected birds was found in lowland areas, and a medium level in foothill areas. One of the main reasons for this is low temperature and high relative humidity in mountainous areas, high air temperature and low relative humidity in low-lying areas and a suitable air temperature and relative humidity in foothill areas for the development of helminth eggs in the external environment.

A Comparison of the Prevalence of the Parasites of the Digestive Tract in Goats from Organic and Conventional Farms

The aim of the study was to compare the prevalence and intensity of gastrointestinal parasitic infections in goats kept on organic (n = 76) and conventional farms (n = 82). In general, a higher prevalence of some gastrointestinal parasitic infections was found in the conventional farms compared to the organic farms: the mean prevalence of Eimeria spp. was 85.4% in conventional farms and 77.6% in organic farms, that of Fasciola hepatica was 6.10% in conventional farms and 2.63% in organic farms, and that of Moniezia expansa was 31.7% and 17.1%, in conventional and organic farms, respectively. Both farm types demonstrated a similar mean prevalence of nematodes (80.3 vs. 84.2%). Conventional farms demonstrated a significantly higher intensity of infection with E. arloingi, Haemonchus spp., Nematodirus spp. and Moniezia expansa compared to organic farms. They also demonstrated a higher intensity of infection with Eimeria spp. than organic farms. The prophylactic programs used to combat parasitic infections in both types of farms appear ineffective and require improvement. There is a need for goat herds to be covered by ongoing parasitological monitoring. It is also recommended that keepers employ rotational or intensive rotational grazing methods and take care to ensure the hygiene of animal quarters and livestock rooms.