scholarly journals Demographic patterns of human antibody levels to Simulium damnosum s.l. saliva in onchocerciasis-endemic areas: An indicator of exposure to vector bites

2022 ◽  
Vol 16 (1) ◽  
pp. e0010108
Author(s):  
Laura Willen ◽  
Philip Milton ◽  
Jonathan I. D. Hamley ◽  
Martin Walker ◽  
Mike Y. Osei-Atweneboana ◽  
...  
Keyword(s):  
Linear Models ◽  
Cumulative Exposure ◽  
Human Antibody ◽  
Adult Males ◽  
Simulium Damnosum ◽  
Endemic Areas ◽  
Demographic Patterns ◽  
Antibody Levels ◽  
Transmission Models ◽  
Age And Sex

Background In onchocerciasis endemic areas in Africa, heterogenous biting rates by blackfly vectors on humans are assumed to partially explain age- and sex-dependent infection patterns with Onchocerca volvulus. To underpin these assumptions and further improve predictions made by onchocerciasis transmission models, demographic patterns in antibody responses to salivary antigens of Simulium damnosum s.l. are evaluated as a measure of blackfly exposure. Methodology/Principal findings Recently developed IgG and IgM anti-saliva immunoassays for S. damnosum s.l. were applied to blood samples collected from residents in four onchocerciasis endemic villages in Ghana. Demographic patterns in antibody levels according to village, sex and age were explored by fitting generalized linear models. Antibody levels varied between villages but showed consistent patterns with age and sex. Both IgG and IgM responses declined with increasing age. IgG responses were generally lower in males than in females and exhibited a steeper decline in adult males than in adult females. No sex-specific difference was observed in IgM responses. Conclusions/Significance The decline in age-specific antibody patterns suggested development of immunotolerance or desensitization to blackfly saliva antigen in response to persistent exposure. The variation between sexes, and between adults and youngsters may reflect differences in behaviour influencing cumulative exposure. These measures of antibody acquisition and decay could be incorporated into onchocerciasis transmission models towards informing onchocerciasis control, elimination, and surveillance.

scholarly journals Human immune response against salivary antigens of Simulium damnosum s.l.: A new epidemiological marker for exposure to blackfly bites in onchocerciasis endemic areas

2021 ◽  
Vol 15 (6) ◽  
pp. e0009512
Author(s):  
Laura Willen ◽  
Maria-Gloria Basáñez ◽  
Vit Dvorak ◽  
Francis B. D. Veriegh ◽  
Frank T. Aboagye ◽  
...  
Keyword(s):  
Immune Response ◽  
Salivary Glands ◽  
Antibody Responses ◽  
Human Antibody ◽  
Humoral Immune ◽  
Simulium Damnosum ◽  
Antigenic Proteins ◽  
Endemic Areas ◽  
Negative Controls ◽  
The Impact

Background Simulium damnosum sensu lato (s.l.) blackflies transmit Onchocerca volvulus, a filarial nematode that causes human onchocerciasis. Human landing catches (HLCs) is currently the sole method used to estimate blackfly biting rates but is labour-intensive and questionable on ethical grounds. A potential alternative is to measure host antibodies to vector saliva deposited during bloodfeeding. In this study, immunoassays to quantify human antibody responses to S. damnosum s.l. saliva were developed, and the salivary proteome of S. damnosum s.l. was investigated. Methodology/Principal findings Blood samples from people living in onchocerciasis-endemic areas in Ghana were collected during the wet season; samples from people living in Accra, a blackfly-free area, were considered negative controls and compared to samples from blackfly-free locations in Sudan. Blackflies were collected by HLCs and dissected to extract their salivary glands. An ELISA measuring anti-S. damnosum s.l. salivary IgG and IgM was optimized and used to quantify the humoral immune response of 958 individuals. Both immunoassays differentiated negative controls from endemic participants. Salivary proteins were separated by gel-electrophoresis, and antigenic proteins visualized by immunoblot. Liquid chromatography mass spectrometry (LC–MS/MS) was performed to characterize the proteome of S. damnosum s.l. salivary glands. Several antigenic proteins were recognized, with the major ones located around 15 and 40 kDa. LC–MS/MS identified the presence of antigen 5-related protein, apyrase/nucleotidase, and hyaluronidase. Conclusions/Significance This study validated for the first time human immunoassays that quantify humoral immune responses as potential markers of exposure to blackfly bites. These assays have the potential to facilitate understanding patterns of exposure as well as evaluating the impact of vector control on biting rates. Future studies need to investigate seasonal fluctuations of these antibody responses, potential cross-reactions with other bloodsucking arthropods, and thoroughly identify the most immunogenic proteins.

Status Signaling Is Absent within Age-and-Sex Classes of Harris' Sparrows

The Auk ◽  
1988 ◽  
Vol 105 (3) ◽  
pp. 424-49 ◽  
Author(s):  
Wendy M. Jackson ◽  
Sievert Rohwer ◽  
Robin L. Winnegrad
Keyword(s):  
Social Status ◽  
Adult Males ◽  
Fighting Ability ◽  
Status Signaling ◽  
Adult Females ◽  
The Status ◽  
Signaling Hypothesis ◽  
Mixed Age ◽  
Badge Size ◽  
Age And Sex

Abstract We tested the status-signaling hypothesis in two groups of same-age and same-sex Harris' Sparrows (Zonotrichia querula). Unlike flocks of mixed age and sex composition, badge size did not correlate with social status in these groups; thus, status signaling does not appear to occur within age-and-sex classes of Harris' Sparrows. Other predictions of the status-signaling hypothesis we tested were that (1) fighting ability and social status should be correlated, and (2) fighting ability and badge size should be correlated. We used a multivariate assessment of body size as an indicator of fighting ability and found no support for either prediction in the flock of adult females. In the flock of adult males, large birds were more dominant (Prediction 1) but fighting ability and badge size were not correlated (contra Prediction 2).

Human antibody response to group A streptococcal teichoic acid

1974 ◽  
Vol 20 (6) ◽  
pp. 853-859 ◽  
Author(s):  
Phillip H. Klesius ◽  
Robert A. Zimmerman ◽  
James H. Mathews ◽  
Arthur H. Auernheimer
Keyword(s):  
Teichoic Acid ◽  
Human Antibody ◽  
Specific Distribution ◽  
Human Sera ◽  
History Of ◽  
Group A ◽  
Major Antigen ◽  
Antibody Levels ◽  
Immunochemical Characteristics ◽  
Rheumatic Heart

The immunochemical characteristics and antibody levels in human sera to a specific group A streptococcal teichoic acid (TA) were studied. This phenol-extracted TA had DL-α-glycerophosphate as the major antigen determinant and not N-acetylglucosamine (N-AGA) as measured by an indirect hemagglutination assay (IHA). The group A streptococcal carbohydrate (A-CHO), N-AGA, and staphylococcal TA did not inhibit the streptococcal TA reaction. In studies of patients with or without history of acute rheumatic fever (ARF) or rheumatic heart disease (RHD), there was an inverse relationship between magnitude of TA hemagglutinating and A-CHO precipitating antibody (Ab) titers. Age-specific distribution of TA-Ab titers was not characteristic of titers observed against other streptococcal protein or carbohydrate antigens.

Clasping Behaviour in Macaca Tonkeana

Behaviour ◽  
1984 ◽  
Vol 89 (1-2) ◽  
pp. 1-28 ◽  
Author(s):  
Bernard Thierry
Keyword(s):  
Primate Species ◽  
Agonistic Interaction ◽  
Adult Males ◽  
Social Grooming ◽  
Substantial Variation ◽  
Social Functions ◽  
Macaca Tonkeana ◽  
Different Origins ◽  
Age And Sex ◽  
Human Primate

AbstractClasping behaviour was studied in two groups of Macaca tonkeana, one being confined in a cage, the other living in a half-hectare park. Five patterns have been distinguished: grasping the hindquarters, grasping, reaching around, embracing and hugging. Clasping may occur in three contexts: greeting, aggression and sexual harassment. There seems to be no direct relationship between context and pattern of clasping. However, there is substantial variation in form and context according to age- and sex-class. Females are the individuals mostly involved in clasps, being initiators as well as receivers; adult males also initiate numerous clasps but receive few. Adult and subadult males especially use grasping the hindquarters while other age- and sex-classes more often use reaching around. Clasping in aggression is more characteristic of females than males. Several behaviours may be associated with clasping. The accompanying behaviours are more frequent in initiator than in receiver. Clasp is often followed by social grooming, mount, wrestle or another clasp. The results of this study in Macaca tonkeana may be compared with information from other studies of non-human primate species. This allows one to draw several conclusions: 1. Frequency, form and distribution of clasping vary from one species to another. There is great variation in certain species, for instance, Macaca tonkeana. 2. Several behaviours usually accompany clasping and may modulate its meaning. 3. Clasping behaviour shows many similarities to mounting behaviour. Although these two behaviours have different origins, they have acquired similar social functions. 4. Clasping plays a prominent role in control of aggression. In Macaca tonkeana, this behaviour is especially used in appeasement (an individual receiving aggression clasps its aggressor during the aggression), reconciliation (an aggressor clasps its antagonist after the aggression) and non-agonistic protection (a third individual intervenes in an agonistic interaction by clasping the aggressor). Non-agonistic protection is an interaction which was until now described only in chimpanzees.

Patterns of human–crocodile conflict in Queensland: a review of historical estuarine crocodile (Crocodylus porosus) management

2017 ◽  
Vol 44 (4) ◽  
pp. 281 ◽  
Author(s):  
M. L. Brien ◽  
C. M. Gienger ◽  
C. A. Browne ◽  
M. A. Read ◽  
M. J. Joyce ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Public Safety ◽  
Linear Models ◽  
East Coast ◽  
Adult Males ◽  
Wet Season ◽  
Temporal And Spatial Patterns ◽  
Crocodylus Porosus ◽  
Temporal And Spatial ◽  
The Government

Context In Queensland, the management of estuarine crocodiles (Crocodylus porosus) by the government is important for ensuring public safety, especially along the populated east coast, where there is a large human population. Aims The present study aimed to determine historical, temporal and spatial patterns of human–crocodile conflict in Queensland. Methods The study used Queensland Government records of estuarine crocodile attacks (1971–2015), sightings by the general public (2003–2015), and removals and relocations for management purposes (1985–2015) to develop General Linear Models describing historical, temporal and spatial patterns. Key results The highest number of attacks, sightings, removals and relocations occurred along the populated east coast between Townsville and the Daintree during wet season months (November–February). There have been 35 crocodile attacks in Queensland since 1971 (total 0.8 per year; fatal 0.3 per year), mostly involving local people or regular visitors (77.1%), specifically adult males (71.4%; mean age 44). There has been an increase in the rate of crocodile attacks over time, with an average of 1.3 per year since 1996, most of which were non-fatal (84%). The number of crocodile sightings has been increasing annually (with a mean of 348 per year since 2011), while the number of crocodiles removed or relocated for management purposes (n = 608) has fluctuating widely each year (range 1–57). Conclusions The level of human–crocodile conflict in Queensland is increasing, and this is likely to be a consequence of increasing human and crocodile populations. While conflict is highest during the wet season, estuarine crocodiles pose a threat to public safety year round. Implications With the increase in conflict, the ongoing management of estuarine crocodiles, through targeted removals in and around areas of higher human habitation and through education, is essential for ensuring public safety into the future.

scholarly journals Endoparasites and vector-borne pathogens in dogs from Greek islands: pathogen distribution and zoonotic implications

2018 ◽  
Author(s):  
Anastasia Diakou ◽  
Angela Di Cesare ◽  
Simone Morelli ◽  
Mariasole Colombo ◽  
Lenaig Halos ◽  
...  
Keyword(s):  
Linear Models ◽  
Clinical Signs ◽  
Rhipicephalus Sanguineus ◽  
Toxocara Canis ◽  
Control Measures ◽  
Rickettsia Conorii ◽  
Vector Borne Diseases ◽  
Vector Borne ◽  
Endemic Areas ◽  
Of Greece

AbstractThe present study investigated the presence of endo- and ecto-parasites, and vector-borne pathogens, in dogs from four islands of Greece. A total of 200 owned and sheltered dogs were examined with different microscopic, serological and molecular methods.Of the examined dogs, 130 (65%) were positive for one or more parasites and/or vector-borne pathogens. The most common zoonotic intestinal helminths recorded were Ancylostomatidae (12.5%) and Toxocara canis (3.5%). Ninety-three dogs (46.5%) seroreacted to Rickettsia conorii. Twenty-two (11%) of them were also PCR positive and 7 (3.5%) showed corpuscoles suggestive of Rickettsia spp. on the blood smears. Nineteen dogs (9.5%) were seropositive for Ehrlichia canis, three of them being also PCR positive. Dogs positive for Anaplasma phagocytophilum-Anaplasma platys (1%), Dirofilaria immitis (0.5%) and Babesia canis (0.5%) were also found. Fleas and ticks were recorded in 53 (26.5%) and 50 (25%) dogs and all specimens were identified as Ctenocephalides felis felis and Rhipicephalus sanguineus sensu latu. Binary multiple univariate Generalized Linear Models were used to investigate factors and clinical signs related to the recorded positivity, while the association of specific signs with the pathogens was evaluated using tests of independence. Knowledge of occurrence and impact of zoonotic parasites and vector-borne pathogens in dog populations is crucial to prevent the infection in animals and people, and to control the risk of spreading of these pathogens in endemic and non-endemic areas.Author summaryBoth owned and sheltered dogs can harbor a variety of intestinal and extra-intestinal endoparasites, as well as vector-borne pathogens and ectoparasites, of zoonotic concern. Dog shelters and stray dogs are present in several touristic areas of Greece, including Sporades and Cyclades islands, where tourists often bring their pets with them, likely travelling from non-endemic to endemic areas. The present study has been carried out with the aim to evaluate the occurrence of the aforementioned pathogens. Data obtained showed that they are present in canine populations of Greece, with possibilities of infection for travelling dogs, which can also contribute to the spreading of zoonotic vector-borne diseases, introducing new pathogens in previously non-endemic areas. For these reasons, a constant monitoring of the epidemiological situation, improving control measures and correct diagnostic approaches are of primary importance for the prevention of canine and human infections, decreasing the spreading of potentially deadly pathogens.

scholarly journals New World screwworm (Cochliomyia hominivorax) myiasis in feral swine of Uruguay: One Health and transboundary disease implications

2020 ◽  
Author(s):  
Martín Altuna ◽  
Paul V. Hickner ◽  
Gustavo Castro ◽  
Santiago Mirazo ◽  
Adalberto A. Pérez de León ◽  
...  
Keyword(s):  
South America ◽  
Rural Areas ◽  
One Health ◽  
Animal Health ◽  
Relative Size ◽  
The Body ◽  
Cochliomyia Hominivorax ◽  
Adult Males ◽  
Feral Swine ◽  
Endemic Areas

Abstract Background: Feral swine (Sus scrofa) are highly invasive and threaten animal and public health in the Americas. Screwworm (Cochliomyia hominivorax) is listed by the World Organization for Animal Health as a notifiable infestation because myasis cases affect livestock, wildlife, and humans in endemic areas, and outbreaks can be of high socioeconomic consequence in regions where screwworm was eradicated. However, a knowledge gap exists on screwworm infestation of feral swine in South America, where screwworm is endemic. Here, we report infestation with screwworm in feral swine harvested in the Department of Artigas, where the Republic of Uruguay shares borders with Brazil and Argentina. Methods: Myiasis caused by the larvae of screwworm were identified in feral swine with the support and collaboration of a local feral swine hunting club over a three-year period in the Artigas Department of Uruguay. Harvested feral swine were examined for the presence of lesions where maggots causing the myiasis could be sampled and processed for taxonomic identification. The sites of myiasis on the body of infested feral swine and geospatial data for each case were recorded. Feral swine sex and relative size were recorded. Temperature and precipitation for the region were obtained from public sources.Results: Myiases caused by screwworms were recorded in 27 of 618 feral swine harvested. Cases detected in males over 40 kg were associated with wounds that, because of their location, were likely caused by aggressive dominance behavior between adult males. The overall prevalence of screwworm infestation in feral swine was associated with ambient temperature, but not precipitation. Case numbers peaked in the warmer spring and summer months. Conclusions: This is the first report for South America of myasis caused by screwworm in feral swine. In contrast to myasis in cattle that can reach deep into host tissues, screwworms in feral swine tended to cause superficial infestation. The presence of feral swine is a challenge to control screwworms in endemic areas. Screwworm populations maintained by feral swine may contribute to human cases in rural areas of Uruguay, which highlights the One Health importance of this invasive host species-ectoparasite interaction.

scholarly journals Sex disparities and neutralizing antibody durability to SARS-CoV-2 infection in convalescent individuals

2021 ◽  
Author(s):  
Alena J. Markmann ◽  
Natasa Giallourou ◽  
D. Ryan Bhowmik ◽  
Yixuan J. Hou ◽  
Aaron Lerner ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Human Antibody ◽  
Antibody Titers ◽  
Sex Disparities ◽  
Binding Antibody ◽  
Male Sex ◽  
Antibody Levels ◽  
First Time

AbstractThe coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has now caused over 2 million deaths worldwide and continues to expand. Currently, much is unknown about functionally neutralizing human antibody responses and durability to SARS-CoV-2. Using convalescent sera collected from 101 COVID-19 recovered individuals 21-212 days after symptom onset with forty-eight additional longitudinal samples, we measured functionality and durability of serum antibodies. We also evaluated associations between individual demographic and clinical parameters with functional neutralizing antibody responses to COVID-19. We found robust antibody durability out to six months, as well as significant positive associations with the magnitude of the neutralizing antibody response and male sex. We also show that SARS-CoV-2 convalescent neutralizing antibodies are higher in individuals with cardio-metabolic comorbidities.SignificanceIn this study we found that neutralizing antibody responses in COVID-19 convalescent individuals vary in magnitude but are durable and correlate well with RBD Ig binding antibody levels compared to other SARS-CoV-2 antigen responses. In our cohort, higher neutralizing antibody titers are independently and significantly associated with male sex compared to female sex. We also show for the first time, that higher convalescent antibody titers in male donors are associated with increased age and symptom grade. Furthermore, cardio-metabolic co-morbidities are associated with higher antibody titers independently of sex. Here, we present an in-depth evaluation of serologic, demographic, and clinical correlates of functional antibody responses and durability to SARS-CoV-2.

Age- and sex-associated differences in isokinetic knee muscle endurance between young children and adults

2009 ◽  
Vol 34 (4) ◽  
pp. 725-731 ◽  
Author(s):  
Mark B.A. De Ste Croix ◽  
Martine A. Deighan ◽  
Sebastien Ratel ◽  
Neil Armstrong
Keyword(s):  
Young Children ◽  
Peak Torque ◽  
Knee Extension ◽  
Total Work ◽  
Adult Males ◽  
Significant Interaction Effect ◽  
Peak Knee ◽  
Knee Muscle ◽  
Main Effects ◽  
Age And Sex

The purpose of this study was to examine the age- and sex-associated differences of repeated isokinetic knee extension and flexion. Fifty one participants, 30 young children (16 boys and 14 girls; aged 11 and 12 years) and 21 adults (9 males and 12 females; aged 18–35 years), agreed to participate in the study. Isokinetic concentric peak knee extension (PET) and flexion (PFT) torque were measured using a calibrated Biodex System 3. Participants performed 4 concentric extension–flexion cycles with maximum effort; after a 2 min rest, 50 continuous concentric cycles were performed at 1.56 rad·s–1. Total work of the extensors (WKEX) and flexors (WKFL) for the complete 50 repetitions was recorded. Average peak torque and average work for the first and last 3 repetitions were calculated to represent the percentage decline in torque and work. There were no significant differences between groups in the peak torque generated during the pretrial and endurance task, suggesting that participants gave a maximal effort at the start of the endurance task. There was a significant interaction effect in the total work done for both extensors and flexors, with adult males producing the greatest amount of work (6622 and 3444 J, respectively). When total work was divided by body mass, there were no significant sex effects, only main effects for group. The percentage decline for PET (40% vs. 60%), PFT (50% vs. 65%), WKET (43% vs. 61%), and WKFL (60% vs. 69%) demonstrated significant main effects for group, with greater fatigue in adults. We found no significant sex effect for fatigue. This study concludes that females do not resist fatigue from repeated isokinetic muscle actions to a greater extent than males, and that the greater fatigue in adults than in children is probably a product of greater initial torque production and work performed.

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