Total Parasite Research Articles

Types and Percentations of Parasitization Egg Parasitoids Spodoptera frugiperda J, E. Smith in North Sulawesi

Corn (Zea mays L) is the main commodity of agricultural crops in Indonesia. There are two groups of corn that are cultivated, namely ordinary corn (food corn) and sweet corn. Food corn is mainly used as a raw material for making food, which is used as a raw material for making animal feed raw materials and other industrial products. Easy cultivation, can grow in various conditions, stable selling prices and easy to market are the main driving force for high interest of the farming community to cultivate it. Spodoptera frugiperda larvae are polyphagous and attack many plant species. S. frugiperda larvae feed on more than 350 species of plants in 76 families. S. frugiperda is a typical migratory pest and this migratory behavior is an adjustment strategy to find a more profitable habitat. S. frugiperda is one of the most dangerous invasive pests due to its short life cycle. An adult female lays 900 – 1200 eggs in her life cycle. The purpose of the study was to inventory and analyze the egg parasitoid of S. frugiperda and the percentage of parasitization The analysis of the types of egg parasitoids of S. frugiperda was carried out through an inventory and identification process, while the percentage of parasitization was carried out using a randomized block design consisting of 5 treatment groups of eggs from 5 regions and three replications. The results of the inventory and identification contained two types of parasitoids, namely: Telenomus sp. and Trichogramma sp. The highest percentage of total parasitization was from Manado City at 85% and the lowest was from Bolaang Mongondow at 5%. Telenomus sp. higher percentage of parasitization than Trichogramma sp. Parasitization percentage of Telenomus sp. on eggs of S. frugiperda the highest came from Manado by 63% and the lowest came from Tomohon by 3%, while the percentage of parasitization of Trichograma sp. The highest came from Manado at 22%, and the lowest came from Bolaang Mongondow Regency at zero percent. In conclusion, there are 2 types of egg parasitoids in S. frugiperda eggs, namely the parasitoid Telenomus sp and the parasitoid Trichogramma sp., the percentage of parasitization of Telenomus sp. on eggs of S. frugiperda the highest sample from Manado and the lowest sample from Tomohon. Percentage of parasitization of Trichograma sp. the highest sample of S. frugiperda eggs from Manado, and the lowest sample from Bolaang Mongondow.

Incidence of Intestinal Parasites in Government and Private School Going Children

Objective: Aim to assess the incidence of intestinal parasites in government and private school going children.
 Methods: The work was conducted from October, 2018 to March, 2019 at Microbiology Laboratory of DAV College, Dhobighat, Lalitpur. A total of 100 stool samples of children aged between 5-12 years were collected from both government and private schools situated in Lalitpur metropolitan city, during school hours. The stool samples were examined for intestinal parasites by Saline wet mount; Iodine wet mount and Formal – ether sedimentation technique. The questionnaires accompanying the queries related to the study were filled.
 Results: Of the total 100 stool samples examined, intestinal parasites were observed in 7% (7/100) of the total stool samples. Among the positive stool samples, 71% (5/7) of the stool samples were from government school’s children whereas 29% (2/7) were from private school’s children. Fifty seven percentage 57% (4/7) girls and 43% (3/7) boys were found to be infected with intestinal parasite in the tested stool samples. Out of total parasite detected, 57% (4/7) were eggs of Ancylostoma duodenale, 29% (2/7) were eggs of Ascaris lumbricoides and 14% (1/7) were cysts of Giardia lamblia. The study indicates that Ancylostoma is the most commonly infecting parasite followed by Ascaris and Giardia.
 Conclusion: Personal hygiene and sanitary condition were responsible for the incidence of intestinal parasites in the school going children. Environmental sanitation improvement and health education promotion will be helpful to reduce the parasitic infection rate.

Improving greater amberjack (Seriola dumerili) defenses against monogenean parasite Neobenedenia girellae infection through functional dietary additives

The main objective of this study was to determine the effect of two feeding additives (cMOS: Actigen®, Alltech Inc., USA) and a phytogenic specifically designed for reducing ectoparasite incidence, combining garlic and labiatae herbal extracts (HERB; Delacon, Austria) on growth performance, stress and immune response of greater amberjack (Seriola dumerili) before and after an experimental parasitization with the skin ectoparasite Neobenedenia girellae, a monogenean with high incidence on Seriola cultured in sea cages. Two parallel trials were conducted in order to determine the effect of 70 days of functional diets supplementation (0.2% cMOS and 200 ppm HERB) on greater amberjack: a) Growth performance and stress resistance and b) disease resistance against N. girellae. Additionally, in order to evaluate the effects of the dietary supplements pre- and post- parasitization challenge against N. girellae, the expression of some immune-related genes was evaluated. The relative expression of Il-1β, piscidin, hepcidin, IgT, tnf-α, muc-2, cathelicidin, complement c3, cd8, and caspase-3 was determined in skin. The activity of protease and lysozyme in serum and skin mucus were also evaluated, as well as parasite load and parasite total size.The use of both functional additives did not affect fish growth performance. However, the dietary supplementation of HERB significantly (p<0.05) reduced circulating cortisol levels after the stress challenge, whereas dietary cMOS significantly (p<0.05) reduced the parasite load and total parasite size. When comparing pre and post parasitization challenge, skin mucus protease activity was significantly (p<0.05) higher in all the treatments before parasitization, while the use of both functional additives increased skin mucus lysozyme activity after challenge. From the eleven immune genes studied, only piscidin was significantly (p<0.05) up-regulated by HERB supplementation before challenge, whereas after parasitization, muc-2 and piscidin were significantly (p<0.05) up-regulated by HERB and tnf-α, il1-β, hep, c3, cd8 and casp3 were up-regulated by both functional additives. Moreover, hep, IgT, cath, c3 and cd8 expressions were negatively correlated with the parasite load.In general, greater amberjack supplementation with cMOS and HERB at the dose used in the present study was effective for reducing stress and for increasing the skin associated lymphoid tissue (SALT) immune response against N. girellae during the infection process.

Characterization of microRNAs expressed in the cystic legion of the liver of Mus musculus perorally infected with Echinococcus multilocularis Nemuro strain.

Alveolar echinococcosis (AE) is a zoonosis caused by the metacestode of Echinococcus multilocularis. The published genome of E. multilocularis showed that approximately 86% of its genome is non-coding. Micro RNAs (miRNAs) are small non-coding regulatory RNAs, and recent studies on parasitic helminths expect miRNAs as a promising target for drug development and diagnostic markers. Prior to this study, only a few studies reported the E. multilocularis miRNA profiles in the intermediate host. The primary objective of this study was to characterize miRNA profiles via small RNA-seq in E. multilocularis Nemuro strain, a laboratory strain of Asian genotype, using mice perorally infected with the parasite eggs. The data were then compared with two previously published small RNA-seq data. We identified 44 mature miRNAs as E. multilocularis origin out of the 68 mature miRNA sequences registered in the miRNA database miRbase. The highest quantities of miRNAs detected were miR-10-5p, followed by bantam-3p, let-7-5p, miR-61-3p, and miR-71-5p. The top two most abundant miRNAs (miR-10-5p and bantam-3p) accounted for approximately 80.9% of the total parasite miRNAs. The highly expressed miRNA repertoire is mostly comparable to that obtained from the previous experiment using secondary echinococcosis created by an intraperitoneal administration of metacestodes. A detailed characterization and functional annotations of these shared miRNAs will lead to a better understanding of parasitic dynamics, which could provide a basis for the development of novel diagnostic and treatment methods for AE.

Prevalencia de la Giardia duodenalis en el centro de bienestar animal “CEIBA”, Rionegro, Colombia (2017)

Determinar la prevalencia de parasitismo de Giardia duodenalis, en el centro de bienestar “CEIBA”, del municipio de Rionegro, Colombia durante junio 2017. Se realizó un estudio descriptivo transversal, no experimental, aleatorio, fueron evaluados 112 coprológicos de caninos del centro de bienestar “CEIBA”, de ambos sexos, todas las edades y alimentación comercial. Fueron sometidos a evaluación coprológica, por extracción directa de ampolla rectal y evaluada en el Laboratorio Clínico de la Corporación Universitaria Lasallista “Hermano Marco Antonio Serna f.s.c”, fueron realizados dos métodos diagnósticos, flotación con solución salina saturada (Willys Molloy) y frotis directo. La presencia de Giardia duodenalis fue categorizado en escala de cruces de 0-3. Se encontraron 60 (55%) muestras con presencia de parásitos, de los cuales 10 (8,92%) estaban infestados por Giardia duodenalis, representando 16,66% de la parasitosis total, para una cruz 2 (20%), con dos cruces 5 (50%) y con tres 3 (30%). La prevalencia de Giardia duodenalis en el centro de bienestar CEIBA, es baja con respecto a datos de prevalencia en otros albergues o centros caninos, lo cual puede estar influenciado por las medidas de prevención y control de la enfermedad.

Life tables for the diamondback moth (Plutella xylostella) in southeast Brazil indicate ants and spiders as leading mortality factors

AbstractThe diamondback moth (DBM), Plutella xylostella (Lep.: Plutellidae), causes significant losses in Brassica crops. Leaf consumption by the larvae reduces plant yield and causes the contamination of heading brassicas. Chemical control usually provides unsatisfactory results due to the quickly developed resistance of DBM populations to insecticides. Thus, natural control by biotic factors (predators, parasitoids, and entomopathogens) is crucial and should be managed upon knowledge of their role as DBM regulators. The leading mortality factors of DBM across the annual seasons in southeast Brazil were investigated by conducting 57 field life tables for 2 years. The highest and lowest total mortalities of DBM occurred in winter (99.7%) and autumn (94%). Predation was the main mortality factor in all seasons. Marginal parasitism rates were higher in spring and lower in autumn, and Oomyzus sokolowskii (Hym.: Eulophidae) accounted for almost 90% of total parasitism. The highest mortalities by rainfall were recorded in spring (44.5%), while physiological death and infection caused low mortalities (≤ 6%) throughout the seasons. In addition, models were built to investigate the main predators acting on the DBM life stages; Araneae, Brachymyrmex bruchi, and Tetramorium simillimum (Hym.: Formicidae) were the predators associated with egg/L1 predation whereas Solenopsis saevissima, T. simillimum and Camponotus spp. (Hym.: Formicidae) were the ones responsible for L4/pupa predation. The L2/L3 stage was the least affected by predation, and the final model for this stage did not include any predator. In light of these findings, habitat manipulation and insecticide selectivity are discussed as measures to preserve the main predators and parasitoid.

Unveiling the effect of dietary essential oils supplementation in Sparus aurata gills and its efficiency against the infestation by Sparicotyle chrysophrii

A microencapsulated feed additive composed by garlic, carvacrol and thymol essential oils (EOs) was evaluated regarding its protective effect in gills parasitized by Sparicotyle chrysophrii in Sparus aurata. A nutritional trial (65 days) followed by a cohabitation challenge with parasitized fish (39 days) were performed. Transcriptomic analysis by microarrays of gills of fish fed the EOs diet showed an up-regulation of genes related to biogenesis, vesicular transport and exocytosis, leukocyte-mediated immunity, oxidation–reduction and overall metabolism processes. The functional network obtained indicates a tissue-specific pro-inflammatory immune response arbitrated by degranulating acidophilic granulocytes, sustained by antioxidant and anti-inflammatory responses. The histochemical study of gills also showed an increase of carboxylate glycoproteins containing sialic acid in mucous and epithelial cells of fish fed the EOs diet, suggesting a mucosal defence mechanism through the modulation of mucin secretions. The outcomes of the in vivo challenge supported the transcriptomic results obtained from the nutritional trial, where a significant reduction of 78% in the abundance of S. chrysophrii total parasitation and a decrease in the prevalence of most parasitic developmental stages evaluated were observed in fish fed the EOs diet. These results suggest that the microencapsulation of garlic, carvacrol and thymol EOs could be considered an effective natural dietary strategy with antiparasitic properties against the ectoparasite S. chrysophrii.

A Study on Serological Reactivity Profile of Different Antigen Preparations with Bancroftian filariasis Human Infection Sera

Lymphatic Filariasis (LF) is one of the incapacitating and mosquito-borne sicknesses that on progression may prompt a few recognizable types of clutters like extreme lymphedema, hydrocele, and elephantiasis. Antigenic preparations of B. malayi adult (BmA), S. cervi adult parasites and microfilariae (mf) total parasite extract were used to analyze the serological reactivity profile with human infectious sera collected from endemic areas of Bancroftian filariasis by performing Western blot and ELISA analysis. Sera from healthy human subjects were also included in the study to determine the variation incurred in the reactivity due to the filariasis infection. Gelelectrophoresis analysis of the crude-extract of BmA revealed seven protein bands while more than ten bands were recognized in S. cervi. our results represent a clear variation in protein patterns among the crude-antigens. ELISA results showed highest prevalence of IgG, IgM and IgG4 antibodies against all antigen preparations when recorded among microfilaraemic chronic infected patients. In both the antigenic preparations, the positive reactions were in the order of microfilaraemic>endemic normal>chronic>acute>nonendemic normal subjects. All sera of Mf+ patients were uniformly positive, while sera of both chronic and endemic normal subjects showed less reactivity. In the present study, we endeavoured to establish the extent of cross-reactivity of antigens derived from animal filarial parasites such as B. malayi and S. cervi with W. bancrofti filariasis sera of human patients. Besides, we further analyzed antibody-isotype profile of IgG, IgG4 and IgM in various human infection sera of bancroftian filarial subjects reactive to heterologous parasite antigens derived from adult worms of S. cervi from bovine and B. malayi from bovine and jirds.

Antagonistic effects of some commonly used herbs on the efficacy of Artemisinin derivatives in the treatment of malaria in experimental mice

BackgroundThe use of herbs in combination with drugs in treatment of malaria is increasing, and this necessitated research on the possible antagonistic, additive, potentiation or synergistic properties of commonly used plants with standard drugs in treatment of malaria. In this study, extracts of Morindamorindiodes (Mm) root, Morindalucida (ML) leaf and Vernonia amygdalina (Va) leaf were combined with artesunate (Ar) and assessed for anti-malarial activities against established Plasmodium berghei NK65 infection in 45 experimental mice randomly distributed into 9 groups and treated at a graded dose of 100 mg/kg for the herbs and herbs–drugs combination, while chloroquine and artesunate was administered at 10 mg/kgResultsAt the end the sixth day, Mm root extract, ML and Va leaf extract reduced parasitaemia by 86.83%, 84.20% and 48.10%, respectively (p < 0.05). A total parasite clearance (100% chemosuppression) was observed in the group treated with artesunate and chloroquine. However, the combination of each extracts of M. lucida, M. morindiodes and V. amygdalina with artesunate significantly reduced the chemosuppression to 89.93%, 89.43% and 86.93%, respectively.ConclusionThis study showed that though the extracts of Morinda morindiodes and Morinda lucida possess convincing antiplasmodial effect when administered singly, the combination of these extracts with artesunate could not produce total parasite clearance. There is need to enlighten the public on the possible setback associated with combined use of antimalarial plants with antimalaria drugs.

Interactions between Two Parasitoids of Tephritidae: Diachasmimorpha longicaudata (Ashmead) and Psyttalia cosyrae (Wilkinson) (Hymenoptera: Braconidae), under Laboratory Conditions.

Simple SummaryWasps, generally referred to as “farmers friends” because of their ability to control devastating fruit flies, were imported from Hawaii and released in Kenya for the management of the invasive Oriental fruit fly Bactrocera dorsalis. It was noted that the introduced wasp had developed a liking for the native fruit fly species Ceratitis cosyra which already has a native wasp controlling it. We therefore undertook a study to understand the interaction of the introduced and native wasp on the invader Oriental and native fruit flies. Our results show that when the native wasp attacks the invader fruit fly, the wasp is killed because of the strong immune system of the oriental fruit fly. The good news is that the introduced wasp efficiently controls both the invader and the native fruit flies. We have discussed these findings based on various scientific principles which favor the co-existence of the two wasps without any detrimental effect on their survival. We have also suggested that more studies be conducted in open field conditions where both fruit flies occur in abundance and choices regarding which fruit fly species to attack are much wider.The braconid wasp, Diachasmimorpha longicaudata (Ashmead), was introduced in Kenya from Hawaii for classical biological control of the invasive tephritid, Bactrocera dorsalis Hendel. Following reports that D. longicaudata had formed new associations with Ceratitis cosyra, laboratory experiments were conducted to assess the interaction between the introduced and the native parasitoid of C. cosyra; Psyttalia cosyrae (Wilkinson) under three scenarios: B. dorsalis only, C. cosyra only and mixed populations of the two species. Parasitoids were introduced to the host as sole, sequential and simultaneous releases. Host searching and probing events were five times higher for D. longicaudata than P. cosyrae with both hosts. Total parasitism was highest (78%) when D. longicaudata was released alone on C. cosyra, compared to 20% for P. cosyrae released on the same host. Releases of P. cosyrae on B. dorsalis resulted in 0% parasitism, compared to 64% parasitism by D. longicaudata. Specific parasitism for P. cosyrae was three times higher when P. cosyrae was released first in sequential releases on C. cosyra compared to when it was released after D. longicaudata. These findings suggest that the two parasitoids can both suppress C. cosyra but B. dorsalis acts as a reproductive sink for P. cosyrae. Our findings should form the basis of field investigations where options are much wider for both parasitoids.

Longer photoperiods through range shifts and artificial light lead to a destabilizing increase in host-parasitoid interaction strength.

Many organisms are experiencing changing daily light regimes due to latitudinal range shifts driven by climate change and increased artificial light at night (ALAN). Activity patterns are often driven by light cycles, which will have important consequences for species interactions. We tested whether longer photoperiods lead to higher parasitism rates by a day-active parasitoid on its host using a laboratory experiment in which we independently varied daylength and the presence of ALAN. We then tested whether reduced nighttime temperature tempers the effect of ALAN. We found that parasitism rate increased with daylength, with ALAN intensifying this effect only when the temperature was not reduced at night. The impact of ALAN was more pronounced under short daylength. Increased parasitoid activity was not compensated for by reduced life span, indicating that increased daylength leads to an increase in total parasitism effects on fitness. To test the significance of increased parasitism rate for population dynamics, we developed a host-parasitoid model. The results of the model predicted an increase in time-to-equilibrium with increased daylength and, crucially, a threshold daylength above which interactions are unstable, leading to local extinctions. Here we demonstrate that ALAN impact interacts with daylength and temperature by changing the interaction strength between a common day-active consumer species and its host in a predictable way. Our results further suggest that range expansion or ALAN-induced changes in light regimes experienced by insects and their natural enemies will result in unstable dynamics beyond key tipping points in daylength.

Retrospective analysis of feline intestinal parasites: trends in testing positivity by age, USA geographical region and reason for veterinary visit

BackgroundThe goals of this retrospective study were to estimate parasite positivity in samples from cats using zinc sulfate fecal flotation by centrifugation (“centrifugation”) and coproantigen and examine trends with age, geographical region and reason for visit to veterinarian. Common methods of parasite detection, such as centrifugal flotation, passive flotation, or direct smear, may underrepresent the true prevalence of intestinal parasites in cats. Coproantigen testing detects more positive samples than traditional methods alone.MethodsFeline fecal test results from the continental USA containing results for fecal exams performed using centrifugation paired with coproantigen results for ascarid, hookworm, whipworm and Giardia were obtained from the database of a national commercial reference laboratory comprised of multiple regional sites.ResultsParasite positivity was highest in samples from young cats and decreased with cat age. The western region of the USA had lower total parasite positivity than other regions for all parasites except Giardia. Cats receiving fecal tests during veterinary wellness visits had only slightly lower parasite positivity than samples from cats during sick clinical visits.ConclusionsThis study showed a larger population of cats are at increased risk of parasitism than commonly believed and coproantigen testing produces more positive test results for the four parasites that antigen can detect than centrifugation of feline fecal samples.

First Report of Native Parasitoids of Fall Armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) in Mozambique.

Simple SummaryIn 2016, a highly destructive insect pest with origin in the Americas was detected in Africa. The pest is known to feed primarily on maize which is a staple food in the continent. Since then, farmers have been using chemical insecticides to control the pest. Chemical insecticides are expensive and harmful to the environment. In this article, the authors Albasini Caniço, António Mexia, and Luisa Santos discuss the possibility of application of an alternative method of control known to be environmentally friendly and economically sustainable in the long term. The method, known as “biological control”, can be easily implemented by farmers, and has the potential to reduce the population of the insect pest and production costs, and bring long term benefits to the environment.The alien invasive insect pest Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), commonly referred to as fall armyworm (FAW), is causing significant losses to maize production in Africa since its detection in 2016. As an emergency response, governments in several countries distributed and/or promoted massive use of synthetic insecticides among smallholder farmers to fight FAW. The inappropriate use of synthetic insecticides by non-trained and ill-equipped farmers raises environmental and health concerns. This study aimed to assess the occurrence of native parasitoids of FAW, their parasitism rates, and relative abundance in the central province of Manica, Mozambique. A field collection of FAW egg masses and larvae was conducted from May to August 2019 (dry season of the 2018/2019 cropping season) and in December 2019 and January 2020 (rainy season of 2019/2020 cropping season). A total of 101 egg masses and 1444 larvae of FAW were collected from infested fields. Five larval parasitoids were recorded, but no egg parasitism was observed. Coccygidium luteum Brullé (Hymenoptera: Braconidae) and Drino quadrizonula Thomson (Diptera: Tachinidae) were the primary parasitoids. Maximum parasitism of 23.68% and 8.86% and relative abundance of 100 and 96.3 were recorded for C. luteum and D. quadrizonula, respectively. Total parasitism by different parasitoid species was at 9.49%. Cultural practices favoring the action of these parasitoids should be advocated.

Plasma Plasmodium falciparum Histidine-rich Protein 2 Concentrations in Children With Malaria Infections of Differing Severity in Kilifi, Kenya.

BackgroundMost previous studies support a direct link between total parasite load and the clinical severity of Plasmodium falciparum malaria infections.MethodsWe estimated P. falciparum parasite loads in 3 groups of children with malaria infections of differing severity: (1) children with World Health Organization–defined severe malaria (n = 1544), (2) children admitted with malaria but without features of severity (n = 200), and (3) children in the community with asymptomatic parasitemia (n = 33).ResultsPeripheral parasitemias were highest in those with uncomplicated malaria (geometric mean [GM] parasite count, 111 064/μL; 95% confidence interval, CI, 86 798–141 819/μL), almost 3 times higher than in those with severe malaria (39 588/μL; 34 990–44 791/μL) and >100 times higher than in those with asymptomatic malaria (1092/μL; 523–2280/μL). However, the GM P. falciparum histidine-rich protein 2 (PfHRP2) values (95% CI) increased with severity, being 7 (4–12) ng/mL in asymptomatic malaria, 843 (655–1084) ng/mL in uncomplicated malaria, and 1369 (1244–1506) ng/mL in severe malaria. PfHRP2 concentrations were markedly lower in the subgroup of patients with severe malaria and concomitant invasive bacterial infections of blood or cerebrospinal fluid (GM concentration, 312 ng/mL; 95% CI, 175–557 ng/mL; P < .001) than in those without such infections (1439 ng/mL; 1307–1584; P < .001).ConclusionsThe clinical severity of malaria infections related strongly to the total burden of P. falciparum parasites. A quantitative test for plasma concentrations of PfHRP2 could be useful in identifying children at the greatest clinical risk and identifying critically ill children in whom malaria is not the primary cause.

Climate and seasonal effects on phenology and biological control of giant whitefly Aleurodicus dugesii (Hemiptera: Aleyrodidae) with parasitoids in southern California, USA

The invasive giant whitefly Aleurodicus dugesii Cockerell (Hemiptera: Aleyrodidae), a pest of many important crops and ornamentals, has established throughout southern California, USA. The parasitoids Encarsia noyesi Hayat (Hymenoptera: Aphelinidae), Idioporous affinis LaSalle and Polaszek (Hymenoptera: Pteromalidae), and Entedononecremnus krauteri Zolnerowich and Rose (Hymenoptera: Eulophidae) were introduced as part of a classical biological control program against giant whitefly. Populations of giant whitefly can still reach high numbers, however, despite biological control efforts. Seasonal variation in giant whitefly population densities and parasitoids' species-specific parasitism rates across three climates types in southern California were examined by repeated censuses during 2015–2016 in order to identify potential underlying factors influencing giant whitefly population dynamics. Giant whitefly population densities did not vary between southern California climate types, but varied seasonally, with the highest observed population densities in the spring. Parasitism rates of all three parasitoids also varied seasonally, with total parasitism reaching a peak in late summer and declining until the start of spring. Only I. affinis parasitism rates varied between climate types. Parasitism rates of I. affinis were the highest of the three parasitoid species observed, followed by E. noyesi and E. krauteri. Potential explanations for these findings and their impact on giant whitefly control are discussed.

Influx of diverse, drug resistant and transmissible Plasmodium falciparum into a malaria-free setting in Qatar

BackgroundSuccessful control programs have impeded local malaria transmission in almost all Gulf Cooperation Council (GCC) countries: Qatar, Bahrain, Kuwait, Oman, the United Arab Emirates (UAE) and Saudi Arabia. Nevertheless, a prodigious influx of imported malaria via migrant workers sustains the threat of local transmission. Here we examine the origin of imported malaria in Qatar, assess genetic diversity and the prevalence of drug resistance genes in imported Plasmodium falciparum, and finally, address the potential for the reintroduction of local transmission.MethodsThis study examined imported malaria cases reported in Qatar, between 2013 and 2016. We focused on P. falciparum infections and estimated both total parasite and gametocyte density, using qPCR and qRT-PCR, respectively. We also examined ten neutral microsatellites and four genes associated with drug resistance, Pfmrp1, Pfcrt, Pfmdr1, and Pfkelch13, to assess the genetic diversity of imported P. falciparum strains, and the potential for propagating drug resistance genotypes respectively.ResultsThe majority of imported malaria cases were P. vivax, while P. falciparum and mixed species infections (P. falciparum / P. vivax) were less frequent. The primary origin of P. vivax infection was the Indian subcontinent, while P. falciparum was mostly presented by African expatriates. Imported P. falciparum strains were highly diverse, carrying multiple genotypes, and infections also presented with early- and late-stage gametocytes. We observed a high prevalence of mutations implicated in drug resistance among these strains, including novel SNPs in Pfkelch13.ConclusionsThe influx of genetically diverse P. falciparum, with multiple drug resistance markers and a high capacity for gametocyte production, represents a threat for the reestablishment of drug-resistant malaria into GCC countries. This scenario highlights the impact of mass international migration on the reintroduction of malaria to areas with absent or limited local transmission.

Evaluation of Angiopoietins 1 and 2 in Malaria-Infested Children.

Background Malaria could affect people of all ages, most especially young children. The study evaluated the levels of serum angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) which are critical regulators of endothelial activation and integrity with some hematological parameters (total white blood cell counts (WBC), total red blood cell counts (RBC), platelet counts, and malaria parasite density) in malaria-infected children. Method A total of 92 blood samples from children between the ages of 6 months to 15 years were analyzed. The samples consisted of 30 cases of severe malaria, 40 cases of uncomplicated malaria, and 22 apparently healthy subjects served as control. Serum Ang-1 and -2 levels were determined using the enzyme-linked immunosorbent assay technique. The hematological parameters were determined using the WHO standard. Results There was significant decrease (p < 0.05) in serum Ang-1 of uncomplicated malaria and severe malaria compared with the control, while significant increase (p < 0.05) was observed in Ang-2 and Ang-2/Ang-1 ratio in uncomplicated malaria and severe malaria compared with the control. RBC and platelet showed significant decrease, while WBC showed significant increase in severe malaria compared with uncomplicated malaria and control. Conclusion This study showed that subjects with malaria infection had a significant increase of Ang-2 and Ang-2 : Ang-1 ratio but presented with a significant decrease of Ang-1. Ang-1 and Ang-2 may be used to determine the severity of malaria infection since their levels differ significantly in malaria subjects compared with the control.

Anthelminthic efficacy of Cymbopogon citratus essential oil (Poaceae) against monogenean parasites of Colossoma macropomum (Serrasalmidae), and blood and histopathological effects

This study investigated the in vitro and in vivo anthelminthic efficacy, histopathological and hematological effects of Cymbopogon citratus essential oil (EO) in Colossoma macropomum. The major compounds of the essential oil were geranial (45.7%) and neral (33.9%). Essential oil was assayed at concentrations of 100, 200, 300, 400 and 500 mg L−1 for in vitro efficacy against monogeneans Anacanthorus spathulatus, Mymarothecium boegeri and Notozothecium janauachensis of C. macropomum. Two controls were considered for in vitro assays, one with the use of cultivation tank water and the other with cultivation tank water +70% alcohol. The concentration of 500 mg L−1 of the EO in vitro assays showed 100% efficacy against the parasites within 5 min of exposure, causing structural damages to their tegument. The 400 and 300 mg L−1 concentrations were 100% effective with 10 min and 30 min of exposure, respectively. The 200 mg L−1 concentration in vitro assays was also 100% effective within 30 min and the 100 mg L−1 treatment was 100% effective within 100 min of exposure. Total parasite mortality in both control groups occurred within 7 h. Efficacy was 47.1% after therapeutic baths of 20 min for three consecutive days with 60 mg L−1 of this EO. In addition, 60 mg L−1 of EO was the highest concentration tolerated by the fish and it had an anesthetic effect, and it caused increase in plasma glucose levels and decrease in leukocytes and lymphocytes number, as well as hyperplasia, lamellar fusion, detachment and aneurysm in C. macropomum gills. A low efficacy against the monogeneans was shown perhaps due to the low concentration of this EO tolerated by C. macropomum and the strategy used for the therapeutic baths, which may be corrected with a lower concentration of EO and more consecutive days for therapeutic baths.

Models suggest pathogen risks to wild fish can be mitigated by acquired immunity in freshwater aquaculture systems

The interaction of pathogens between wild and farmed aquatic animal populations is a concern that remains unclear and controversial. Ichthyophthirius multifiliis, a ciliated protozoan parasite, is a pathogen of freshwater finfish species with geographic and host range that causes significant economic losses in aquaculture. Flow-through farming systems may facilitate the transfer of such a parasite with free-living stages between farmed and wild stocks. Here, experimental and field study infection data are used to describe the infection dynamics of Ichthyophthirius multifiliis in rainbow trout using a simple macroparasite model by including host resistance. The study considered flow-through farming systems with a single or two age-class compartments and simulated the transfer of the parasite between farmed and wild fish populations. Results suggest that aquaculture can promote the prevalence of the resistance in wild stocks by increasing the parasite population in the wild environment. At the same time, acquired resistance in the farmed fish population may protect the wild fish population from lethal effects of the parasite by reducing the total parasite population. This study offers a promising mathematical basis for understanding the effects of freshwater aquaculture in disease spread in wildlife, developing risk assessment modeling, and exploring new ways of aquaculture management.

Expert‐level automated malaria diagnosis on routine blood films with deep neural networks

Over 200 million malaria cases globally lead to half a million deaths annually. Accurate malaria diagnosis remains a challenge. Automated imaging processing approaches to analyze Thick Blood Films (TBF) could provide scalable solutions, for urban healthcare providers in the holoendemic malaria sub-Saharan region. Although several approaches have been attempted to identify malaria parasites in TBF, none have achieved negative and positive predictive performance suitable for clinical use in the west sub-Saharan region. While malaria parasite object detection remains an intermediary step in achieving automatic patient diagnosis, training state-of-the-art deep-learning object detectors requires the human-expert labor-intensive process of labeling a large dataset of digitized TBF. To overcome these challenges and to achieve a clinically usable system, we show a novel approach. It leverages routine clinical-microscopy labels from our quality-controlled malaria clinics, to train a Deep Malaria Convolutional Neural Network classifier (DeepMCNN) for automated malaria diagnosis. Our system also provides total Malaria Parasite (MP) and White Blood Cell (WBC) counts allowing parasitemia estimation in MP/μL, as recommended by the WHO. Prospective validation of the DeepMCNN achieves sensitivity/specificity of 0.92/0.90 against expert-level malaria diagnosis. Our approach PPV/NPV performance is of 0.92/0.90, which is clinically usable in our holoendemic settings in the densely populated metropolis of Ibadan. It is located within the most populous African country (Nigeria) and with one of the largest burdens of Plasmodium falciparum malaria. Our openly available method is of importance for strategies aimed to scale malaria diagnosis in urban regions where daily assessment of thousands of specimens is required.