Successful introgression of wMel Wolbachia into Aedes aegypti populations in Fiji, Vanuatu and Kiribati

Pacific Island countries have experienced periodic dengue, chikungunya and Zika outbreaks for decades. The prevention and control of these mosquito-borne diseases rely heavily on control of Aedes aegypti mosquitoes, which in most settings are the primary vector. Introgression of the intracellular bacterium Wolbachia pipientis (wMel strain) into Ae. aegypti populations reduces their vector competence and consequently lowers dengue incidence in the human population. Here we describe successful area-wide deployments of wMel-infected Ae. aegypti in Suva, Lautoka, Nadi (Fiji), Port Vila (Vanuatu) and South Tarawa (Kiribati). With community support, weekly releases of wMel-infected Ae. aegypti mosquitoes for between 2 to 5 months resulted in wMel introgression in nearly all locations. Long term monitoring confirmed a high, self-sustaining prevalence of wMel infecting mosquitoes in almost all deployment areas. Measurement of public health outcomes were disrupted by the Covid19 pandemic but are expected to emerge in the coming years.

Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses

Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville. Methods: The wMel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results: Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km ² in four stages over 28 months with full community support.  A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion: Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km ² quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission.

Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses

Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville. Methods: The wMel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results: Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km ² in four stages over 28 months with full community support.  A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion: Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km ² quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission.

Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses

Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville.

Methods: The wMel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release.

Results: Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km ² in four stages over 28 months with full community support.  A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases.

Conclusion: Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km ² quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission

The queenslandensis and the type Form of the Dengue Fever Mosquito (Aedes aegypti L.) Are Genomically Indistinguishable

BACKGROUND

The mosquito Aedes aegypti (L.) is a major vector of viral diseases like dengue fever, Zika and chikungunya. Aedes aegypti exhibits high morphological and behavioral variation, some of which is thought to be of epidemiological significance. Globally distributed domestic Ae. aegypti have often been grouped into (i) the very pale variety queenslandensis and (ii) the type form. Because the two color forms co-occur across most of their range, there is interest in understanding how freely they interbreed. This knowledge is particularly important for control strategies that rely on mating compatibilities between the release and target mosquitoes, such as Wolbachia releases and SIT. To address this question, we analyzed nuclear and mitochondrial genome-wide variation in the co-occurring pale and type Ae. aegypti from northern Queensland (Australia) and Singapore.

METHODS/FINDINGS

We typed 74 individuals at a 1170 bp-long mitochondrial sequence and at 16,569 nuclear SNPs using a customized double-digest RAD sequencing. 11/29 genotyped individuals from Singapore and 11/45 from Queensland were identified as var. queenslandensis based on the diagnostic scaling patterns. We found 24 different mitochondrial haplotypes, seven of which were shared between the two forms. Multivariate genetic clustering based on nuclear SNPs corresponded to individuals' geographic location, not their color. Several family groups consisted of both forms and three queenslandensis individuals were Wolbachia infected, indicating previous breeding with the type form which has been used to introduce Wolbachia into Ae. aegypti populations.

CONCLUSION

Aedes aegypti queenslandensis are genomically indistinguishable from the type form, which points to these forms freely interbreeding at least in Australia and Singapore. Based on our findings, it is unlikely that the presence of very pale Ae. aegypti will affect the success of Aedes control programs based on Wolbachia-infected, sterile or RIDL mosquitoes.

Cytologic findings in a fetal intracranial teratoma. A case report

BACKGROUND

Fetal neoplasms are very rare. Recently we had the opportunity to examine the fine needle aspiration (FNA) biopsy of a fetal intracranial teratoma.

CASE

The tumor was found in a 30-week-gestation fetus; the mother was 32 years old, gravida 4, para 1. She presented with a rapid increase in abdominal girth over a two-week period. An ultrasound scan showed severe fetal hydrocephalus and a massive intracranial tumor thought to be a teratoma because of variations in echogenicity and spotty calcification. An FNA biopsy was performed under ultrasound guidance. It showed mainly neuroepithelial cells, so a differential diagnosis of malignant neuroepithelial tumor was considered. At autopsy, several other tissue types were found in the tumor, consistent with a teratoma.

CONCLUSION

Advances in diagnosis of fetal anomalies by ultrasound have been associated with an increase in the use of fetal interventions performed in utero. This includes the availability of fetal surgery in some centers. FNA biopsy of fetal lesions does not appear to be well described. Increased experience with this technique is necessary if its full potential is to be realized.

CNS findings in iniencephaly: case report and literature review

A male iniencephalic foetus of about 25 weeks gestation is described. The baby was born to a 22-year-old mother, who presented with abdominal pain of 1 day duration. An ultrasound scan at that time showed multiple foetal anomalies and the pregnancy was terminated. A stillborn baby was delivered. At autopsy, characteristic findings of iniencephaly were seen in the dysmorphic foetus as well as multiple structural abnormalities. The autopsy results, with emphasis on the neuropathological findings, are described and various hypotheses of the pathogenesis of iniencephaly are discussed with reference to theories of embryological development and other cases in the literature.

Dermatological presentations of infantile myofibromatosis: a review of 27 cases

Twenty-seven cases of infantile myofibromatosis presenting with dermatological manifestations were retrospectively reviewed. Approximately 80% were solitary lesions and 50% of these appeared on the head and neck. Around 60% were present at or soon after birth. Most lesions were dermal or subcutaneous, although some were intramuscular and intraosseous. The clinical appearance was non-specific leading to frequent misdiagnosis. While most patients presented with nodules, atrophic depressed lesions and warty pedunculated lesions were also seen. Although 7% of lesions recurred after excision, spontaneous resolution was also documented.

Human immunodeficiency virus-related primary cutaneous aspergillosis

A 31-year-old Caucasian man with AIDS developed a crusted violaceous plaque under adhesive tape near a central venous catheter insertion site. Histological examination demonstrated a ruptured hair follicle containing collections of fungal hyphae typical of Aspergillus spp. A culture of the biopsy material grew Aspergillus fumigatus. The patient responded to removal of the catheter and the occlusive dressing, in addition to itraconazole therapy. Aspergillosis must be considered in the differential diagnosis of cutaneous lesions in human immunodeficiency virus-infected patients, in particular when the lesion occurs under adhesive tape or an occlusive dressing.

High-resolution maps of regional ventilation utilizing inhaled fluorescent microspheres

The regional deposition of an inhaled aerosol of 1.0-micron diameter fluorescent microspheres (FMS) was used to produce high-resolution maps of regional ventilation. Five anesthetized, prone, mechanically ventilated pigs received two 10-min inhalations of pairs of different FMS labels, accompanied by intravenous injection of 15.0-micron radioactive microspheres. The lungs were air dried and cut into 1.9-cm3 pieces, with notation of the spatial coordinates for each piece. After measurement of radioactive energy peaks, the tissue samples were soaked in 2-ethoxyethyl acetate, and fluorescent emission peaks were recorded for the wavelengths specific to each fluorescence label. The correlation of fluorescence activity between simultaneously administered inhaled FMS ranged from 0.98 to 0.99. The mean coefficient of variation for ventilation for all 10 trials (47.9 +/- 8.1%) was similar to that for perfusion (46.2 +/- 6.3%). No physiologically significant gravitational gradient of ventilation or perfusion was present in the prone animals. The strongest predictor of the magnitude of regional ventilation among all animals was regional perfusion (r = 0.77 +/- 0.13).

A system for the reconstruction and analysis of dendritic fields

We report here the development of a fast and 'user friendly' Semiautomatic Neuron Reconstruction and Analysis System (SANRAS) based on a Zeiss Universal microscope, Kontron Microscope Control Processor (MCP), and Apple Macintosh SE microcomputer. Four programs for digitisation and analysis have been written; STAGE, CONVERTZ, RECON and SHOLL. Cells are digitised by superimposing ocular crosshairs on a dendrite and tracing directly, the stage position in x, y, and z co-ordinates being recorded by the computer at points indicated by a keypress. Cells can be digitised from serial thick sections and dendritic reconstructions can be visualised on screen, rotated and viewed from any angle. Output is given either to a Hewlett Packard colour plotter or to a laser printer, in graphical form, and as a summary of various metrical and topological parameters. Radial Scholl diagrams of dendritic trees may also be produced. Dendritic branching patterns of Golgi-impregnated neurons of the left and right intermediate medial hyperstriatum ventrale of the chick are described.

Quantitative autoradiographic analysis of the distribution of [3H]muscimol binding to GABA receptors in chick brain

Quantitative receptor autoradiography was used to investigate the distribution of high-affinity GABA receptors (GABAA) in left and right hemispheres of the brains of 3-week-old chicks. The receptors were labelled with the potent GABA agonist [3H]muscimol. High levels of [3H]muscimol labelling were found throughout the fore-, mid-, and hindbrain, though considerable variation was found in different regions. In the telencephalon the highest concentration of specific binding was found in the hyperstriatum ventrale followed by the neostriatum, and then the lobus parolfactorius of the paleostriatal complex, whilst in the diencephalon highest levels of labelling were present in the infundibulum. In the midbrain distinct lamination was observed in the high levels of [3H]muscimol binding in the optic tectum and in the hind brain the highest density of labelling occurred in the granular layers of the cerebellum. Levels of labelling were generally low in the brainstem regions. The distribution of [3H]muscimol binding in the optic tectum and in the hind brain the highest density of labelling occurred in the granular layers of the cerebellum. Levels of labelling were generally low in the brainstem regions. The distribution of [3H]muscimol binding sites is in good agreement with our previous work on the distribution of GABA-immunoreactivity in the chick brain.

Nurse practitioner research: issues in practice and theory

Since the inception of the nurse practitioner role, numerous studies have focused on the characteristics of NPs, including their educational preparation, their practice settings, demographic characteristics of clients, cost analysis, and the quality of services within a medical context. The two major conclusions of the majority of these studies have been that the delivery of health care by nurse practitioners has been fully accepted by patients, and that nurse practitioners are competent in the delivery of quality care. A brief historical overview of nurse practitioners is presented; the major methodological and conceptual issues of nurse practitioner research are reviewed. Views on practice issues and nursing theory development are shared, and directions for future nurse practitioner research are explored.

Projections to the posterior visual hyperstriatal region in the chick: an HRP study

The thalamic nuclei in birds are known to receive afferents from the retina and project to the hyperstriatum. However, the efferent connections of one of these, the anterior lateral nucleus (LA) have been a subject of controversy for some time. Using horseradish peroxidase tracing techniques we have shown that, in the chick, the efferents of the thalamus (including the LA) project to the visual hyperstriatum. In the case of the LA this is to the right hyperstriatum only and to posterior regions not previously regarded as having a visual function.

The visual hyperstriatal region in the chick: potentials evoked by electrical stimuli

The visual hyperstriatum of the 100-g chick has been investigated for responses evoked by electrical stimuli to the optic papilla. The visual hyperstriatum is not restricted to the anterior forebrain; posterior regions are also responsive, but for maximum response in amplitude the stimulating electrodes need to be re-positioned and, for reliable detection, a 10-fold gain in amplification is required.

Prescribing behaviors of primary care nurse practitioners

The prescribing practices of 18 primary care nurse practitioners (NPs) with 1,683 patients over a six-month period were examined through a randomly selected audit of over 1,700 prescriptions. The results showed that NPs prescribed a very limited number of well known, relatively simple drugs to a young, female healthy population. The prescription/visit rate was 0.26. Most drugs were initiated for the first time rather than refilled. There was minimal physician consultation regarding drug use during the visit. The results provide evidence of the ability of nurse practitioners to prescribe drugs and should aid in the further legalization of this aspect of the primary care role.

The Ginsberg Experiment: Modern and Prehistoric Evidence of a Bone-Flaking Technology

The discovery of butchered and modified bones of extinct Pleistocene fauna from Old Crow Flats, Yukon Territory, and the Dutton and Selby sites, Colorado, provides some of the earliest evidence for man in the New World. However, the significance of these discoveries rests entirely on the ability to determine whether these remains were modified by man. The results of experiments of elephant butchering, bone fracturing, and bone tool manufacturing support the hypothesis that these modified bones can be used to identify the presence of cultural activities.