Prehospital transfusion of labile blood product using intraosseous perfusion with multi-lumen extender: Why not?

BACKGROUND: French prehospital military medical teams are provided with labile blood products to effectively address hemorrhagic shock. In combat environment, standard good medical practice may limit efficacy of therapeutic goals regarding damage control resuscitation. STUDY DESIGN AND METHODS: We present here a case report describing the management of a soldier heavily wounded during a helicopter forward medical evacuation in Sahel region. RESULTS: We report the challenge encountered by medical team using only a humeral intraosseous route available due to severity of lesions and challenging environment. In this configuration, multi-lumen extender enabled transfusion of two units of packed red blood cells and two units of plasma, and analgesia while limiting manipulation and dislodgment of the fragile intraosseous route. This situation, outside of usual good medical practice, raises issues of hemolysis, physicochemical compability of drugs and blood products, and consequences on flow rate reduction. DISCUSSION: With this case, we emphasize the benefit of multi-lumen extender associated with intraosseous route for early management of heavy casualties in harsh prehospital environment. Literature suggests that hemolysis and physicochemical compability should remain limited. The main issue of this setting consists of flow reduction and can be addressed by prioritizing humeral route, and using counter pressure cuffs, until a second peripheral or central line is available and management can resume without the need for multi-lumen extender.

Fasciolosis in the Mediterranean island of Corsica (France): Insights from epidemiological and malacological investigations.

Fasciolosis is a re-emergent parasitic disease of worldwide significance with a major global impact on livestock health and production. In the French Mediterranean island of Corsica, fasciolosis has been recognized for a long time but little is known about its dynamic as the main investigations are outdated. Three compartments - definitive domestic hosts, intermediate hosts and environment - involved in fasciolosis transmission were studied by applying an integrative and extensive approach: (1) farm and abattoir surveys, (2) snail sampling, identification and infection prospection, and (3) snail habitat analysis; and (4) a questionnaire-based survey to inquire about husbandry practices and environmental risks. Our results indicate a significant circulation of the liver flukes in Corsican livestock, with 90% (252/279) of the sampled farms testing positive for anti-F. hepatica antibodies. At the abattoir, 46% (67/149) of cattle were positive for F. hepatica antibodies and eggs were present in the bile of 19% (26/139) bovines. In addition, high prevalence of Dicrocoelium dendriticum (69%) was observed in slaughtered cattle. Malacological surveys registered the occurrence of several lymnaeid species in a variety of habitats throughout the island. In particular, we report for the first time the presence of the invasive lymnaeid snail Pseudosuccinea columella in Corsica, a potential intermediate host for F. hepatica. We also found that the presence of Galba truncatula and, to a lesser extent, that of Peregriana peregra, is associated with altitude. Fasciola hepatica DNA was detected in the latter species occurring at two different sites. Finally, a questionnaire-based study revealed risky management practices among Corsican farmers, low perception of transmission and a suboptimal use of flukicide treatments as main control strategy. Our results show that animal fasciolosis in Corsica is characterised by a significant circulation and a favourable epidemiological scenario for transmission to occur.

Prevalence and risk factors associated with urogenital schistosomiasis among primary school pupils in Nigeria.

Urogenital schistosomiasis is a neglected tropical disease that is endemic to Nigeria and one which continues to pose a public health problem especially among school-age children in rural communities. This study was carried out in remote areas where most people depend on natural water bodies and rainwater for their daily water needs. The present research investigates the prevalence of urogenital schistosomiasis and the significant risk factors associated with the infection among primary school children in Nigeria. From August 2019 to December 2019, a total of 5514 primary school-age children from twelve sites were diagnosed with the presence of Schistosoma haematobium eggs in their urine. Socio-demographic, sociocultural, and socioeconomic indices and data on behaviors (e.g contact frequency with freshwater bodies) were also collected for each diagnosed individual through the use of a questionnaire. Associations between each of these variables and disease infection were tested using a multivariate logistic regression. A total of 392 of the 5514-urine samples were positive for the infection, the overall prevalence reached 7.1% and ranged from 4.6% (East Nigeria) to 15,9% (West Nigeria). Multivariate logistic regression analyses showed that the significant risk factors associated with S. haematobium infection are frequent contact with freshwater bodies (rivers/steams), with an adjusted odds ratio (AOR) of 4.92; 3.34-7.24, washing/swimming, AOR: 46.49; 27.64-78.19, and fishing, AOR: 11.57; 8.74-15.32. For socioeconomic factors, primary education of fathers which resulted in an AOR of 1.63; 1.01-2.45 was significantly associated with the infection. The socio-demographic factor for the 12-14 year age group had an AOR of 1.68; 1.21-2.33, and was also significantly associated with the disease. Nigeria remains endemic for urogenital schistosomiasis as indicated by the data obtained from all the studied sites, and it is clear that efforts need to be intensified in order to control and eradicate the disease throughout the country.

Population genetics of African Schistosoma species.

Blood flukes within the genus Schistosoma (schistosomes) are responsible for the major disease, schistosomiasis, in tropical and sub-tropical areas. This disease is predominantly present on the African continent with more than 85% of the human cases. Schistosomes are also parasites of veterinary importance infecting livestock and wildlife. Schistosoma population genetic structure and diversity are important characteristics that may reflect variations in selection pressures such as those induced by host (mammalian and snail) environments, habitat change, migration and also treatment/control interventions, all of which also shape speciation and evolution of the whole Schistosoma genus. Investigations into schistosome population genetic structure, diversity and evolution has been an area of important debate and research. Supported by advances in molecular techniques with capabilities for multi-locus genetic analyses for single larvae schistosome genetic investigations have greatly progressed in the last decade. This paper aims to review the genetic studies of both animal and human infecting schistosome. Population genetic structures are reviewed at different spatial scales: local, regional or continental (i.e. phylogeography). Within species genetic diversities are discussed compared and the compounding factors discussed, including the effect of mass drug administration. Finally, the ability for intra-species hybridisation questions species integrities and poses many questions in relation to the natural epidemiology of co-endemic species. Here we review molecularly confirmed hybridisation events (in relation to human disease) and discuss the possible impact for ongoing and future control and elimination.

Large outbreak of urogenital schistosomiasis acquired in Southern Corsica, France: monitoring early signs of endemicization?

OBJECTIVES: Clustered cases of urogenital schistosomiasis were reported in April 2014 among French and German tourists linked to exposure in the Cavu River, Southern Corsica, France, between 2011 and 2013. We set up national surveillance for autochthonous urogenital schistosomiasis to document the largest possible number of cases in order to identify potential sites of transmission and to determine the extent of the outbreak in France and Corsica. METHODS: The early response consisted mostly of prohibiting swimming in the river, performing a nationwide serologic screening of all persons exposed to the river between 2011 and 2013 and treating confirmed cases. Physicians were asked to report all patients with one or more positive antischistosome serologic test. Cases were defined as occurring in a resident of France with serologic evidence of schistosomiasis or schistosome eggs in urine and no history of contact with freshwater in known endemic areas. We documented symptoms as well as place and time of exposure to freshwater for all subjects. To estimate the outbreak size, we modelled the effect of the 2014 nationwide screening on the 2011-2015 time series of serodiagnosed schistosomiasis cases using log-linear autoregression. RESULTS: In 2014, a total of 106 autochthonous cases were reported, including 35 symptomatic infections. All patients had swum in the Cavu during summer 2013. Over 30 000 persons were likely screened for autochthonous schistosomiasis. The model-estimated outbreak size was 338 cases, including 36 serodiagnosed in 2015. CONCLUSIONS: Besides the 2013 outbreak, there is evidence of small-scale transmission in 2015 in Corsica. Early detection and control of recurrences requires raising community and medical awareness.

Two families of exocomets in the ß Pictoris system.

The young planetary system surrounding the star ß Pictoris harbours active minor bodies. These asteroids and comets produce a large amount of dust and gas through collisions and evaporation, as happened early in the history of our Solar System. Spectroscopic observations of ß Pictoris reveal a high rate of transits of small evaporating bodies, that is, exocomets. Here we report an analysis of more than 1,000 archival spectra gathered between 2003 and 2011, which provides a sample of about 6,000 variable absorption signatures arising from exocomets transiting the disk of the parent star. Statistical analysis of the observed properties of these exocomets allows us to identify two populations with different physical properties. One family consists of exocomets producing shallow absorption lines, which can be attributed to old exhausted (that is, strongly depleted in volatiles) comets trapped in a mean motion resonance with a massive planet. Another family consists of exocomets producing deep absorption lines, which may be related to the recent fragmentation of one or a few parent bodies. Our results show that the evaporating bodies observed for decades in the ß Pictoris system are analogous to the comets in our own Solar System.

Pyrenean ptarmigans decline under climatic and human influences through the Holocene.

In Europe, the Quaternary is characterized by climatic fluctuations known to have led to many cycles of contraction and expansion of species geographical ranges. In addition, during the Holocene, historical changes in human occupation such as colonization or abandonment of traditional land uses can also affect habitats. These climatically or anthropically induced geographic range changes are expected to produce considerable effective population size change, measurable in terms of genetic diversity and organization. The rock ptarmigan (Lagopus muta) is a small-bodied grouse occurring throughout Northern hemispheric arctic and alpine tundra. This species is not considered threatened at a continental scale, but the populations in the Pyrenees are of concern because of their small population size, geographical isolation and low genetic diversity. Here, we used 11 microsatellites to investigate genetic variations and differentiations and infer the overall demographic history of Pyrenean rock ptarmigan populations. The low genetic variability found in these populations has been previously thought to be the result of a bottleneck that occurred following the last glacial maximum (i.e., 10,000 years ago) or more recently (i.e., during the last 200 years). Our results clearly indicate a major bottleneck affecting the populations in the last tenth of the Holocene. We discuss how this decline can be explained by a combination of unfavorable and successive events that increased the degree of habitat fragmentation.

Vertebrate host protective immunity drives genetic diversity and antigenic polymorphism in Schistosoma mansoni.

Schistosomes are gonochoric blood parasites with a complex life cycle responsible for a disease of considerable medical and veterinary importance in tropical and subtropical regions. Understanding the evolution of schistosome genetic diversity is clearly of fundamental importance to interpreting schistosomiasis epidemiology and disease transmission patterns of this parasite. In this article, we investigated the putative role of the host immune system in the selection of male genetic diversity. We demonstrated the link between genetic dissimilarity and the protective effect among male worms. We then compared the proteomes of three male clones with different genotypes and differing by their capacity to protect against reinfection. The identified differences correspond mainly to antigens known or supposed to be involved in the induction of protective immunity. These results underline the role played by host immune system in the selection of schistosome genetic diversity that is linked to antigenic diversity. We discuss the evolutionary consequences in the context of schistosome infection.

Transferability of microsatellite markers among economically and ecologically important galliform birds.

We used the partially sequenced genomes of the turkey and chicken to find a large number of microsatellite markers. We then characterized 10 polymorphic microsatellite markers developed by cross-species amplification from economically and ecologically important birds to various European sub-species of the grey partridge. Even though we used cross-species amplification, a high degree of polymorphism was conserved in all microsatellite markers. Cross-species amplification from birds of economic and ecological interest, such as chicken and turkey, could be an attractive approach to develop microsatellite markers and to use these to manage wild and captive populations of other galliforms, such as the grey partridge.

Regulation of Anguillicola crassus (Nematoda) infrapopulations in their definitive host, the European eel, Anguilla anguilla.

The parasitic nematode Anguillicola crassus was recently introduced into populations of the European eel, Anguilla anguilla. We investigated, under experimental conditions, the regulation of A. crassus infrapopulations. We tested the effects of (1) the resource-limited habitat of the parasite and (2) the coexistence of several developmental stages in its niche (the swim-bladder) on the composition of the infrapopulations. The results revealed that the respective effects of these factors differed substantially during the course of the infection. Third-stage larvae (L3s) establishment would not be constrained by the size of the swim-bladder. Their moult to fourth-stage larvae (L4s) would be accelerated as the number of L3s increased. The moulting time of L4s to adults would be reduced by males and would be constrained by the size of the swim-bladder. However, the moult of L4s to adults and their further development would be synchronized with those of the opposite sex. At the time of mating, the number of males and the body weight of adults would depend on the size of the swim-bladder. Soon after the laying of eggs, the developmental constraint on the late L3s would decrease. When adults die, constraints would cease and late larval stages would moult to become adults.

Cheap, rapid and efficient DNA extraction method to perform multilocus microsatellite genotyping on all Schistosoma mansoni stages.

Schistosomes are endoparasites causing a serious human disease called schistosomiasis. The quantification of parasite genetic diversity is an essential component to understand the schistosomiasis epidemiology and disease transmission patterns. In this paper, we propose a novel assay for a rapid, low costly and efficient DNA extraction method of egg, larval and adult stages of Schistosoma mansoni. One euro makes possible to perform 60,000 DNA extraction reactions at top speed (only 15 min of incubation and 5 handling steps).

Schistosome monogamy: who, how, and why?

Schistosomes represent a unique animal model for comparative analyses of monogamy. Indeed, schistosomes are classified at the lowest taxonomical level of monogamous species and lack complex social interactions, which could alter our understanding of their unusual mating system. Elements discussed here include the fact that monogamy in schistosomes could be an ancestral state between hermaphroditism and polygyny or polygynandry and the occurrence of mate changes. In addition, hypotheses are proposed to explain monogamy in schistosomes (e.g. female dispersion, the need for paternal care, oviposition site limitation or aggressiveness, and mate guarding). We also propose future experimental and analytical approaches to improve our understanding of the schistosomes' mating system.

Cheap, rapid and efficient DNA extraction method to perform multilocus microsatellite genotyping on all Schistosoma mansoni stages

Schistosomes are endoparasites causing a serious human disease called schistosomiasis. The quantification of parasite genetic diversity is an essential component to understand the schistosomiasis epidemiology and disease transmission patterns. In this paper, we propose a novel assay for a rapid, low costly and efficient DNA extraction method of egg, larval and adult stages of Schistosoma mansoni. One euro makes possible to perform 60,000 DNA extraction reactions at top speed (only 15 min of incubation and 5 handling steps).

Influence of pattern of exposure, parasite genetic diversity and sex on the degree of protection against reinfection with Schistosoma mansoni.

This paper analyzed, experimentally, the influences of pattern of exposure, parasite genetic diversity, and parasite sex on the degree of protection against reinfection with Schistosoma mansoni in the mouse. The results show that, (1) in infections with one male parasite genotype, successive infections induced a significant decrease in the infectivity of the parasite and significant increases in the spleen and liver weights compared to mass infections, (2) successive infections with one male genotype induced a significant decrease in the infectivity of the parasite compared to successive infections with five male genotypes, and (3) genotype infectivities were determined by the order at which they were used in the successive infections. These results are discussed in terms of protective effect and concomitant immunity and provide an ecological explanation of the natural sex-biased dispersal toward the male schistosomes.

A model to explain the origin of a parasite sex-specific population structure.

A discrete time model was built to understand the origin of the sex-specific population structure of the human blood fluke, Schistosoma mansoni. We have estimated both male/female individual ratio and male/female genotype ratio of this parasite taking into account all the experimental published values on differential male and female life-history traits all along the life cycle. We considered in our model male and female life-history traits when both separated and together. The model showed that both male/female individual ratio and male/female genotype ratio of S. mansoni adults are biased toward males in each combination. This bias was more important in male/female genotype ratio than in the male/female individual ratio for the same initial values of cercarial development success. This model could explain the sex specific population structure of this parasite. Firstly, we showed that the male-biased individual ratio finds its origin in the vertebrate host. Secondly, we showed that the male-biased genotype ratio originates prior to any interrelationship between adult worms and could generate by itself a sex-specific genetic structure.

Preliminary study on sex-related inflammatory reactions in mice infected with Schistosoma mansoni.

The aim of this study was to investigate the contribution of the sex of both the parasite and the host to the inflammatory response induced in unisexual infections of Schistosoma mansoni in mice. Organ weight, cell count and the delayed type hypersensitivity reaction were used as tools in this comparative study. The inflammatory reactions differed as a function of the sex of both the host and the parasite. Female mice showed a stronger inflammatory reaction to schistosome infection than males, while male schistosomes induced a stronger inflammatory response compared to females. The host-related differences in the inflammatory reaction may reflect differences in the factors affecting the immune defence of male and female mice. The differences in the inflammatory response induced by the parasite are discussed in terms of the quantity and quality of antigens among male and female worms.

Relationship between worm burden and male proportion in Schistosoma mansoni experimentally infected rodents and primates. A meta-analytical approach.

This paper investigates the relationship between the worm burden and the male proportion of adult Schistosoma mansoni. This relationship was tested using data from the literature on S. mansoni experimentally infected rodents and primates. The analyses were performed within each animal model (rat, mouse, hamster and monkey) and showed positive linear relationships between worm burden and male proportion. An analysis between the four animal models showed the same positive linear relationship. The role of the genetic diversity of male and female schistosomes in this relationship is discussed.

Male-female larval interactions in Schistosoma mansoni-infected Biomphalaria glabrata.

This paper investigates Schistosoma mansoni male-female larval interactions in simultaneous bi-miracidial Biomphalaria glabrata infections. Larval interactions were analysed at four levels of infection: (i), miracidial infectivity, estimated by the prevalence of mollusc infection; (ii), mollusc pathology, measured by the mollusc growth and survival; (iii), dynamics of the cercarial sex ratio; and (iv), cercarial infectivity, measured as the success of development into adulthood. Our results showed that larval interactions exist in S. mansoni-infected B. glabrata. These interactions do not occur in miracidial infectivity, but occur in mollusc pathology, cercarial sex ratio dynamics and cercarial infectivity. Regarding mollusc pathology, we showed that the bi-miracidially-infected molluscs were smaller than the mono-miracidially-infected ones. This could be the result of larval competition. Regarding the dynamics of the cercarial sex ratio, we showed larval female superiority as compared with male larvae inducing the shedding of female-biased cercarial sex ratios. These sex ratios were rhythmic and could be the reflection of an external expression of the intramolluscan development. Regarding cercarial infectivity, we showed that the simultaneous presence of both sexes in a mollusc increased the cercarial infectivity. This result could be due to male-female larval synergism.

Experimental observations on the sex ratio of adult Schistosoma mansoni, with comments on the natural male bias.

The sex ratio of adult worms has been observed biased towards males in Schistosoma mansoni under natural conditions. The origin of this bias is unknown. This paper determines whether males are more infective than females under controlled experimental bisexual conditions, and hence if the sex ratio is male-biased as a consequence of this. The male and female cercarial infectivities in uni- and bisexual vertebrate host infections using a range of controlled cercarial sex ratios were studied. The results showed that, in experimental unisexual infections, male cercariae were more infective than females, and that in experimental bisexual infections, male cercarial infectivity was similar to that of female, irrespective of cercarial sex ratio. Furthermore, cumulative male and female cercarial infectivity was maximal when sex ratio was equilibrated. The unbiased sex ratios obtained in our experimental bisexual infections are discussed in terms of behavioural and/or biochemical male female interaction. Alternative explanations of the natural biased sex ratio are proposed.