Outbreak Of Infestation Research Articles

Effect of disinfectants on viability of Trichuris skrjabini eggs

The nematodoses are considered the most numerous group of cosmopolitan diseases among animal and human parasitoses. The representatives of the genus Trichuris attract special attention as pathogens of nematodoses. Their high fecundity, resistance to the influence of environmental factors and the ability to disperse create a serious ecological hazard and the risk of new outbreaks of infestation. The aim of the research was to establish the ovicidal efficiency of modern disinfectants on the embryogenesis of eggs of Trichuris skrjabini nematodes isolated from sheep. In laboratory conditions, two preparations were tested, DZPT-2 (mixture of glutaraldehyde, sodium dodecyl sulfate, essential oil) and Dixclor (mixture of sodium bisulfate, sodium chlorite, sodium percarbonate) at different concentrations and times of exposure. We established that DZPT-2 disinfectant showed a high level of ovicidal efficiency (97.5–100%) against T. skrjabini eggs at 4.5% concentration during exposure for 6–12 h and 5.0% concentration during exposure for 3–12 h. Dixclor showed a high level of ovicidal efficiency (100%) against Trichuris eggs at a concentration of 0.24% for exposures of 12 and 24 hours. Decreasing the concentration of disinfectants reduced the level of their ovicidal efficiency and led to the development of a greater number of viable eggs of T. skrjabini. Degenerative changes in the test cultures of T. skrjabini eggs caused by the tested disinfectants were characterized by the appearance and accumulation of air bubbles under the egg shell, the cessation of embryonic development at the bean-like embryo stage, loosening and resorption of the embryo inside the eggs, thinning and destruction of their shell, deformation of the eggs, and swelling of the egg plugs. Such destructive changes in eggs in experimental test cultures were also confirmed by the indicators of their morphometric parameters. Under the influence of DZPT-2 and Dixclor on the 54th day of cultivation, the length of the eggs was lower by 3.9%, and their width was greater by 4.8–5.1% compared to similar indicators in the control test culture. The obtained results allow one to recommend the tested disinfectants in defined and effective concentrations and exposures for effective control and prevention of trichurosis on livestock farms.

Seed Phenotyping and Genetic Diversity Assessment of Cowpea (V. unguiculata) Germplasm Collection

Cowpea is a nutrient-rich staple legume and climate-resilient crop for vulnerable agroecosystems. However, the crop still remains underutilized, mainly due to its narrow genetic base, and the production is often ravaged by aphid infestation outbreaks. Thus, genetic diversity assessment and the detection of defense-related alleles are fundamental to germplasm management and utilization in breeding strategies to support food safety in climate change times. A germplasm collection of 87 cowpea landraces sourced from Greece was subjected to seed phenotyping, SSR genotyping and to screening for the presence of aphid-resistance-conferring alleles. Significant diversity in the species’ local germplasm was revealed. The landraces were grouped in metapopulations based on their broader geographical origin. High amounts of variation and statistically significant differences were detected among the landraces regarding the seed morphological traits, the seed color and eye color according to MANOVA (Wilk’s λ = 0.2, p < 0.01) and significant correlations were revealed among these features according to Pearson’s test (p < 0.05). High levels of genetic polymorphism were detected for the metapopulations, ranging from 59% (VuPop3) to 82% (VuPop4). The AMOVA revealed that 93% of the molecular diversity was distributed among the landraces of each metapopulation. Further population structure analysis presumed the existence of two inferred populations, where in population A, 79% of the landraces have a cream/cream-brown seed coat, whereas in population B, 94% of the landraces are brown-ochre to black-seeded. Molecular screening for alleles conferring aphid resistance revealed the correspondence of 12 landraces to the resistant genotype of TVu-2876. The study highlights the importance of cowpea germplasm collection genetic diversity, as a source of important agronomic traits, to support breeding efforts and expand cowpea cultivation to foster food security and agriculture sustainability and diversification in climate change.

Effects of grape phylloxera leaf infestation on grapevine growth and yield parameters in commercial vineyards: a pilot study

Grape phylloxera (Daktulosphaira vitifoliae) can infest both roots and leaves of Vitis species. In commercial vineyards planted with Vitis vinifera scions grafted on rootstocks, grape phylloxera infestation is generally limited to root feeding. Vineyards are, however, increasingly subjected to vineyard-wide foliar infestations that last throughout the growing season. While some vineyards are affected by the infestation pressure of external leaf-feeding populations, other annually affected V. vinifera vineyards do not have these in their vicinity. Much is known about the damage potential of grape phylloxera root feeding; however, data on how phylloxera leaf infestation affects V. vinifera grapevines in commercial vineyards are lacking. This study, therefore, aimed to assess whether grapevine growth and yield are affected due to leaf infestation as it occurred in three commercial vineyards in the study area. Treatments were based on phylloxera leaf infestation and additional defoliation. Single-leaf carbon acquisition was measured with gas exchange analyses on healthy and galled leaves. Pruning weight and internode length were measured to assess the effect of leaf infestation and the effect of plant growth and vigour on leaf gall outbreaks. Yield quantity and quality were measured, and grapes were vinified for sensory analyses. Furthermore, using enzymatic analyses, non-structural carbohydrates were analysed in perennial wood. A significant decrease in sugar content in grapes (10 %) and starch reserves in perennial wood (11 %) was found in the most heavily infested vineyard. Grape must of infested plants in another vineyard furthermore showed a significantly higher level of titratable acid (7.5 %). Significant infestation effects seen in one vineyard were not significant in the other two vineyards. No significant differences were seen for carbon acquisition, harvest quantity, wine sensory analysis, pruning weight or internode length. The overall effect of phylloxera leaf infestation in the studied vineyards was, therefore, marginal. Grapevine vigour did not differ between infested vines, insecticide-sprayed vines, and vines on which no leaf infestation outbreaks took place. By analysing phylloxera leaf infestation under field conditions, these preliminary results form a basis for future long-term field studies about phylloxera leaf feeding on Vitis vinifera within the context of other biotic and abiotic plant stresses.

Hot spot area analysis of onion armyworm outbreak in Nueva Ecija using geographic information system

Onion is one of the high-value crops in the Philippines and Nueva Ecija is the leading onion producer in the country. Though onion is one of the most profitable high-value crops, it is very susceptible to armyworm infestations resulting in huge income loss to the farmers. To avoid losses in the future and expedite assistance by the government in the heavily infested areas, the pattern, spatial information and mapping of armyworm infestation and damage are information of vital importance. However, its importance is still far from realization by the farmers and decision makers, which at present are still depending on the traditional methods of estimating losses in yield/ha basis. Geographic Information System is the most advanced technology used in resources mapping which could also use in identifying heavily infested area through “Hot Spot Analysis”. Hotspot analysis was conducted in this study to identify the spatial pattern and possible sources of armyworm infestation outbreaks. The result shows that the onion area of San Jose was classified as the highest hot spot area of armyworm infestation. On the other hand, the onion areas in the municipalities of Cuyapo, Guimba, San Leonardo, Rizal, General Natividad, Laur, and Bongabon, were also found to be high hot spot areas of infestation, though in moderate scale of damage. The municipalities of Lupao, Munoz, Gabaldon, Santo Domingo, Talavera, Quezon, and Aliaga, were found to be at very low to moderate hotspot status. GIS was proven to be effective in generating hot spot maps of armyworm based on the levels of infestation in the onion areas of Nueva Ecija.

Outbreak of infestation with body lice in a home for assisted living, Austria, 2018

Outbreak of infestation with body lice in a home for assisted living, Austria, 2018

An Update on the Occurrence and Damage Caused to Cashew by Gypona cerea DeLong & Freytag (Hemiptera: Cicadellidae) in Northeastern Brazil

Abstract: We have identified specimens of the leafhopper Gypona cerea DeLong & Freytag (Cicadellidae: Iassinae: Gyponini) collected from a crop of dwarf cashew (Anacardium occidentale Linnaeus 1753) located in Canto do Buriti, Piaui, Northeastern Brazil. The damage caused to the crop included inflorescences covered with sticky exudates, presence of sooty mold, and yellowing and drying of new shoots and inflorescences. Such documentation serves as a warning about possible outbreaks of infestation in the region and the likelihood of its expansion to other cashew producing areas.

First report of the parasitic copepod Lernaea cyprinacea (Copepoda: Lernaeidae) on gobioid fishes (Teleostei: Gobonellidae) in southern Europe

Lernaea cyprinacea is a non host-specific parasitic copepod known to infest many freshwater fish species. Outbreaks of infestations by this ectoparasite may cause mass mortality of parasitized fishes. L. cyprinacea has been found mostly on pelagic species. Records on small benthic fish species are less common. Especially rare are infestations of Gobioidei adapted to a benthic life style, with reports restricted to Asia and, in Europe, to the Ponto-Caspian region. Although it is cosmopolitan, L. cyprinacea has rarely been found in Italy. One of the few Italian localities with documented infestations is Lake Trasimeno, a lake with an economically important fishery. Although endoparasites of commercially interesting fish species in this lake are well documented, information about ectoparasites is rare. In May 2015, specimens of two gobioids − Knipowitschia panizzae and Pomatoschistus canestrinii − infested with L. cyprinacea were sampled at the south shore of Lake Trasimeno. Both gobies are not native to the lake. This is the first documentation of gobioid fishes as hosts of L. cyprinacea in Italy and in Europe (outside of the Ponto-Caspian region). Although both gobies are not optimal hosts (small size, short life expectancy) they have the potential to carry and to transmit the parasite in freshwater habitats, e.g. by unintentional introduction with fry of other fish species.

Head lice predictors and infestation dynamics among primary school children in Norway.

Background.Health providers need to know which measures to take and children to prioritize in order to decrease costs associated with head lice infestations.Objective.Our aim was to determine the most important predictors for head lice and identify the major drivers of an infestation outbreak in a low-prevalence area.Methods.The study was based on three datasets of head lice prevalence (retrospective, point prevalence and prospective approach) from primary school children (ages 6–12) at 12 schools in Oslo, Norway. The tested predictors were siblings with lice, individual and household characteristics as well as class and school affiliation. Self-reported monthly incidences (prospective approach) of head lice were used to evaluate infestation dynamics.Results.Infested siblings strongly increased the odds of head lice infestation of school children (odds ratio 36, 26 and 7 in the three datasets) whereas having short hair halved the odds. Household characteristics were of minor importance, and class affiliation proved more important than school affiliation. Having head lice in one school term increased the odds of an infestation in the next, but this effect diminished over time. About 97% of all self-reported infestations were noted in two consecutive months or less.Conclusions.With the exception of hair length, we have found that individual and household characteristics are of minor importance to predict head lice infestations in a low-prevalence country and that unnoticed transmissions in school classes and families are likely to be the major driver upon outbreaks.

Modeling mountain pine beetle infestation with an agent-based approach at two spatial scales

Extensive outbreaks of tree-killing insects have been occurring in many parts of North America, including the province of British Columbia, raising concerns about the health of pine forest ecosystems. The dynamic phenomenon of mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, infestation outbreaks is an inherent spatial and temporal complex process. Agent-based modeling (ABM) facilitates simulating spatial interactions that describe the ecological context in which insect populations spread. The main objective of this study was to develop a model of the MPB forest infestation dynamics. This spatially explicit model integrates geographic information systems (GISs) and ABM to simulate MPB outbreaks at the tree and landscape scales, providing spatiotemporal information of annual distribution and patterns of MPB outbreaks. This prototype was implemented with geographic data generated from aerial overview surveys carried out by the B.C. Ministry of Forests and Range, for the study site in Kamloops, Canada. Results show the direct influence that vigorous forest stands and trees have on higher breeding rates, and therefore in the MPB population increment at a tree scale, in a period of 5 years. The simulation results at the landscape level help to determine the most probable locations of future MPB infestations in a time frame of 10 years.

Detection of Babesia bigemina infection in strains of Rhipicephalus ( Boophilus) microplus collected from outbreaks in South Texas

The sudden death of several cattle infested experimentally with Rhipicephalus ( Boophilus) microplus led to a clinical investigation into the reasons for the unexpected mortality. Microscopic evidence for Babesia bigemina infection was found in blood smears from the affected animals and a PCR assay was designed to detect the presence of B. bigemina and Babesia bovis in all R. microplus strains received and propagated at the laboratory. The assay utilizes a nested PCR approach with the first PCR amplifying a well-conserved segment from the Babesia 18S ribosomal RNA gene followed by a nested PCR with Babesia species-specific primers and annealing temperatures enabling amplification of the 18S ribosomal RNA gene fragment specific to either B. bigemina or B. bovis. DNA from groups of 50 larvae was extracted using a rapid DNA preparation protocol, which consisted of grinding the frozen tick larvae in PCR buffer and boiling the mixture for 5 min. The assay sensitivity allowed for the detection of the equivalent of a single infected tick larva. R. microplus eggs were also analyzed, but yolk protein viscosity created inconsistent results with the crush and boil DNA isolation protocol, necessitating the use of a more extensive proteinase K digestion-based DNA purification method. We detected the presence of B. bigemina in all strains of R. microplus currently reared at the laboratory and 4 of 26 strains collected from infestation outbreaks in Texas by the U.S. Cattle Fever Tick Eradication Program.

Les myiases d'importance économique

A simplified list of the principal Diptera capable of causing myiasis is followed by a brief presentation of the biology, lesions inflicted, and methods of treatment and control of the myiases of economic importance. Cochliomyiasis caused by Cochliomyia hominivorax is of greatest interest, in view of the damage and losses caused by this disease. A brief account of the outbreak of infestation in Libya illustrates the danger of this parasite. Other important traumatic myiases are described: that due to Chrysomya bezziana, which causes an African myiasis similar to cochliomyiasis, and those due to Lucilia cuprina and related species. Hypodermyiasis (warble fly infestation) and oestrosis (nasal bot fly infestation in sheep) still cause major economic losses in domestic animals, justifying their inclusion in control campaigns. The same applies to stomach bot flies of the family Gasterophilidae. The account of each myiasis includes notes on parasiticides which have been found to be effective. Given the rapidity with which a parasite can now be transported from one continent to another, it is important for Veterinary Services to be well-informed and vigilant.

Status and environmental impact of toxaphene in the Third World — A case study of African agriculture

Toxaphene was early introduced to Egypt by Hercules Co. in 1955 to combat the main cotton insect pests: the cotton leaf worm Spodoptera littoralis, the pink bollworm Pectinophera gossypiella, and the spiny bollworm Earias insulana. Formulated Emulsfiable concentrate (E.C.). Toxaphene (60% Chlorinated camphene) was used in four successive sprays during the cotton season on an area of 1.5 million acres at the rate of 2L/acre during the first three seasons (1956–1958). The rate was then increased to 3L/acre during the next two seasons (1959–1960). In the 1961 season, a disaster occurred when toxaphene even at 4L/acre failed to stop the infestation outbreak of the cotton leaf worm resulting in a loss of 50% of the national cotton yield of that season. This failure was caused by the build up of cotton leaf worm resistance to toxaphene. The total amount of toxaphene used during these six seasons was estimated to be 54,000 metric tons of the active ingredient. Although the use of Toxaphene in Egypt was banned in 1962 due to the irreversible cotton leaf worm resistance, new sources of toxaphene residues kept comming to Egypt across the River Nile Basin countries which were still heavily using toxaphene (Sudan, Ethiopia, Tanzania and Congo). As well, the illegal use of toxaphene by fishermen was another source of toxaphene pollution. The residues of toxaphene seem to be quite persistent as shown by the few studies carried out. Levels up to 10 ppm were detected in the River Nile water, soil and other biological samples in the Egyptian environment. (Saleh, 1981). Long term exposure to sublethal levels are expected to be a potential hazard to human health and the environment. A follow up program to monitor and assess the risk and hazards of toxaphene exposure is suggested for implementation in Egypt as a model for developing countries heavily exposed to toxaphene residues.

Amyloodinium ocellatum (Brown, 1931) (Dinoflagellida) infestations in cultured marine fish at Eilat, Red Sea: epizootiology and pathology

Abstract. Since 1977, repeated outbreaks of infestation by Amyloodinium ocellatum (Dinoflagellida) in cultured gilthead bream Sparus aurata L. and seabass Dicen‐trarchus labrax (L.) resulted in sporadic and mass mortalities. Fingerlings and yearlings as well as breeders were affected and, since 1978, larval and post‐larval S. aurata in the hatchery. Infestations in juvenile and breeder fish were located predominantly on the gills and mucosal integument but in larval fish only the skin rather than the gills was infested. Histopathological changes of the infested gills are described. Vacuolar degeneration of the cells penetrated by the parasites’ rhizoids was evident at the site of attachment and cloudy swelling was apparent in the surrounding epithelial cells. In heavy infestations the entire epithelium of the gill filaments underwent hyperplasia with consequent fusion of the lamellae. Where hyperplasia was extensive the cells gradually degenerated while the inner epithelial layer showed distinct spongiosis and in some cases completely disintegrated. All heavily infested gills lacked mucous cells.

The changing distribution of helminthic diseases in the United States.

• Trichinosis exemplifies the importance of helminthic diseases in this country; the number of cases of trichinosis in the United States exceeds that in any other country in the world. Tropical diseases are brought to the United States by people returning or immigrating from other countries; an example is American trypanosomiasis, the first case of which in the United States was reported in Texas in 1955. Schistosoma mansoni and Wuchereria bancrofti are being brought to the mainland of the United States from the West Indies, especially from Puerto Rico. Many cases of schistosomiasis have been reported since 1950, especially in northern cities such as New York and Chicago. Parasites endemic in one area within the United States are carried occasionally into other areas, as is illustrated by an outbreak of infestation with Strongyloides in a school in Illinois after the arrival of children from New Mexico. The authors give many other examples, and the fact that these problems are not peculiar to the United States is illustrated by recent migrations of Jamaicans to England, Indonesians to Holland, and Algerians to France. Two million American tourists have visited foreign countries since World War II. Increased attention to the principles of sanitation and hygiene is urgently needed in order to reduce the disability now caused by parasites and to prevent parasites from establishing themselves in new areas.