scholarly journals Impact of Sexual Transmission to Sex-specific Attack Rates in Zika Epidemics

2018 ◽  
Author(s):  
Ana Carolina W.G. de Barros ◽  
Kaline G. Santos ◽  
Eduardo Massad ◽  
Flávio Codeço Coelho

ABSTRACTIn 2015 and 2016 South America went through the largest Zika epidemic in recorded history. One important aspect of this epidemic was the impact on newborns due to the effect of Zika on development of the central nervous system leading to severe malformations. Another aspect of the Zika epidemic which became evident from the data was the importance of the sexual route of transmission leading to increased risk for women. Here propose a mathematical model for the transmission of the Zika virus including sexual transmission via all forms of sexual contact, as well as simplified vector transmission, assuming a constant availability of mosquitoes. From this model we derive an expression for ℛ0 which can be used to study and analyze the relative contributions of the different routes of Zika transmission and the male to female sexual transmission route vis-a-vis vectorial transmission. We also fit the model to data from the 2016 Zika epidemic in Rio de Janeiro, to estimate the values of key parameters of the model.

2019 ◽  
Vol 7 (4) ◽  
pp. 112
Author(s):  
Ana Carolina W. G. de Barros ◽  
Kaline G. Santos ◽  
Eduardo Massad ◽  
Flávio Codeço Coelho

In 2015–2016, South America went through the largest Zika epidemic in recorded history. One important aspect of this epidemic was the importance of sexual transmission in combination with the usual vectorial transmission, with asymmetrical transmissibilities between sexual partners depending on the type of sexual contact; this asymmetry manifested itself in data as an increased risk to women. We propose a mathematical model for the transmission of the Zika virus including sexual transmission via all forms of sexual contact, as well as vector transmission, assuming a constant availability of mosquitoes. From this model, we derive an expression for R 0 , which is used to study and analyze the relative contributions of the male to female sexual transmission route vis-à-vis vectorial transmission. We also perform Bayesian inference of the model’s parameters using data from the 2016 Zika epidemic in Rio de Janeiro.


Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2244
Author(s):  
Elizabeth Balint ◽  
Amelia Montemarano ◽  
Emily Feng ◽  
Ali A. Ashkar

Following the recent outbreak of Zika virus (ZIKV) infections in Latin America, ZIKV has emerged as a global health threat due to its ability to induce neurological disease in both adults and the developing fetus. ZIKV is largely mosquito-borne and is now endemic in many parts of Africa, Asia, and South America. However, several reports have demonstrated persistent ZIKV infection of the male reproductive tract and evidence of male-to-female sexual transmission of ZIKV. Sexual transmission may broaden the reach of ZIKV infections beyond its current geographical limits, presenting a significant threat worldwide. Several mouse models of ZIKV infection have been developed to investigate ZIKV pathogenesis and develop effective vaccines and therapeutics. However, the majority of these models focus on mosquito-borne infection, while few have considered the impact of sexual transmission on immunity and pathogenesis. This review will examine the advantages and disadvantages of current models of mosquito-borne and sexually transmitted ZIKV and provide recommendations for the effective use of ZIKV mouse models.


2021 ◽  
Author(s):  
Saeed Vafaei-Nezhad ◽  
Masood Vafaei-Nezhad ◽  
Mehri Shadi ◽  
Samira Ezi

Maternal Diabetes is one of the most common metabolic disorders resulting an increased risk of abnormalities in the developing fetus and offspring. It is estimated that the prevalence of diabetes during pregnancy among women in developing countries is approximately 4.5 percent and this range varies between 1 to 14 percent in different societies. According to earlier studies, diabetes during pregnancy is associated with an increased risk of maternal and child mortality and morbidity as well as major congenital anomalies including central nervous system (CNS) in their offspring. Multiple lines of evidence have suggested that infants of diabetic women are at risk of having neurodevelopmental sequelae. Previous studies reveal that the offspring of diabetic mothers exhibit disturbances in behavioral and intellectual functioning. In the examination of cognitive functioning, a poorer performance was observed in the children born to diabetic mothers when compared with the children of non-diabetic mothers. Therefore, it is important to study the possible effects of maternal diabetes on the hippocampus of these infants.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4830 ◽  
Author(s):  
Murilo S. de Abreu ◽  
João P.M. Messias ◽  
Per-Ove Thörnqvist ◽  
Svante Winberg ◽  
Marta C. Soares

The monoamines serotonin and dopamine are important neuromodulators present in the central nervous system, known to be active regulators of social behaviour in fish as in other vertebrates. Our aim was to investigate the region-specific brain monoaminergic differences arising when individual cleaners face a client (mutualistic context) compared to when they are introduced to another conspecific (conspecific context), and to understand the relevance of visual assessment compared to the impact of physical contact with any partner. We demonstrated that serotoninergic activity at the diencephalon responds mostly to the absence of physical contact with clients whereas cerebellar dopaminergic activity responds to actual cleaning engagement. We provide first insights on the brain’s monoaminergic (region-specific) response variations, involved in the expression of cleaner fishes’ mutualistic and conspecific behaviour. These results contribute to a better understanding of the monoaminergic activity in accordance to different socio-behavioural contexts.


PEDIATRICS ◽  
1977 ◽  
Vol 60 (2) ◽  
pp. 153-156 ◽  
Author(s):  
David S. Folland ◽  
Ralph E. Burke ◽  
Alan R. Hinman ◽  
William Schaffner

From November 1974 through December 1975 a study was made of all reported cases of gonorrhea in children under 10 years of age in Tennessee. Clinical manifestations of the 73 subjects identified included vaginal infection (48), urethritis (11), conjunctivitis (8), and ophthalmia neonatorum (6). A total of 203 relatives and associates of 54 subjects was cultured. Fifty-four (27%) had gonorrhea; 43 of these were relatives. A history of sexual contact was found in 18 children, including seven where the contact had a positive culture for Neisseria gonorrhoeae. Sexual transmission was common in children with vaginitis or urethritis. In nine cases, sexual abuse or child neglect was suspected. The recognition of a child with gonococcal infection identifies a cluster of family members and associates who are at increased risk of having gonorrhea.


2020 ◽  
pp. 237-238
Author(s):  
John F. Peppin ◽  
Joseph V. Pergolizzi ◽  
Robert B. Raffa ◽  
Steven L. Wright

The authors summarize the harmful and understudied aspects of the overuse of benzodiazepines. Increased and longer-term use of benzodiazepines has been observed to lead to side effects such as sedation, cognitive issues, abuse, and dependence, as well as many other unanticipated side effects that do not fit their known mechanism of action in the central nervous system. Data also shows a correlation between concomitant use of benzodiazepines and opioids and increased risk of death from overdose. The authors advocate for stricter guidelines for prescribing benzodiazepines, as well as close clinical monitor and shorter-term treatment plans.


2021 ◽  
Vol 11 ◽  
Author(s):  
Lintao Wang ◽  
Zhiguang Ren ◽  
Li Ma ◽  
Yanjie Han ◽  
Wenqiang Wei ◽  
...  

COVID-19 has spread rapidly worldwide since its outbreak and has now become a major public health problem. More and more evidence indicates that SARS-CoV-2 may not only affect the respiratory system but also cause great harm to the central nervous system. Therefore, it is extremely important to explore in-depth the impact of SARS-CoV-2 infection on the nervous system. In this paper, the possible mechanisms of SARS-CoV-2 invading the central nervous system during COVID-19, and the neurological complications caused by SARS-CoV-2 infection were reviewed.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
W H Watson ◽  
A Nash ◽  
C Lee ◽  
M D Patz ◽  
J M Newcomb

Synopsis The neuropeptide small cardioactive peptide (SCP) plays an integrative role in exciting various motor programs involved in feeding and locomotion in a number of gastropod species. In this study, immunohistochemistry, using monoclonal antibodies against SCPB, was used to localize SCPB-like-immunoreactive neurons in the central nervous system, and map their connections to various tissues, in the nudibranch, Melibe leonina. Approximately 28–36 SCPB-like-immunoreactive neurons were identified in the M. leonina brain, as well as one large neuron in each of the buccal ganglia. The neuropil of the pedal ganglia contained the most SCPB-like-immunoreactive varicosities, although only a small portion of these were due to SCPB-like-immunoreactive neurons in the same ganglion. This suggests that much of the SCPB-like immunoreactivity in the neuropil of the pedal ganglia was from neurons in other ganglia that projected through the pedal–pedal connectives or the connectives from the cerebral and pleural ganglia. We also observed extensive SCPB innervation along the length of the esophagus. Therefore, we investigated the impact of SCPB on locomotion in intact animals, as well as peristaltic contractions of the isolated esophagus. Injection of intact animals with SCPB at night led to a significant increase in crawling and swimming, compared to control animals injected with saline. Furthermore, perfusion of isolated brains with SCPB initiated expression of the swim motor program. Application of SCPB to the isolated quiescent esophagus initiated rhythmic peristaltic contractions, and this occurred in preparations both with and without the buccal ganglia being attached. All these data, taken together, suggest that SCPB could be released at night to arouse animals and enhance the expression of both feeding and swimming motor programs in M. leonina.


Author(s):  
Onur Akın ◽  
İbrahim Eker ◽  
Mutluay Arslan ◽  
Süleyman Tolga Yavuz ◽  
Sevil Akman ◽  
...  

AbstractBackground:Childhood obesity may lead to neuronal impairment in both the peripheral and the central nervous system. This study aimed to investigate the impact of obesity and insulin resistance (IR) on the central nervous system and neurocognitive functions in children.Methods:Seventy-three obese children (38 male and 35 female) and 42 healthy children (21 male and 21 female) were recruited. Standard biochemical indices and IR were evaluated. The Wechsler Intelligence Scale for Children-Revised (WISC-R) and electroencephalography (EEG) were administered to all participants. The obese participants were divided into two groups based on the presence or absence of IR, and the data were compared between the subgroups.Results:Only verbal scores on the WISC-R in the IR+ group were significantly lower than those of the control and IR– groups. There were no differences between the groups with respect to other parameters of the WISC-R or the EEG. Verbal scores of the WISC-R were negatively correlated with obesity duration and homeostatic model assessment-insulin resistance (HOMA-IR) values. EEGs showed significantly more frequent ‘slowing during hyperventilation’ (SDHs) in obese children than non-obese children.Conclusions:Neurocognitive functions, particularly verbal abilities, were impaired in obese children with IR. An early examination of cognitive functions may help identify and correct such abnormalities in obese children.


2010 ◽  
Vol 16 (10) ◽  
pp. 1173-1177 ◽  
Author(s):  
M. Shahbazi ◽  
H. Ebadi ◽  
D. Fathi ◽  
D. Roshandel ◽  
M. Mohamadhosseni ◽  
...  

Background: The multifunctional cytokine interleukin-6 (IL-6) is involved in inflammatory processes in the central nervous system. It is well documented that amount of IL-6 is increased in serum, cerebrospinal fluid and central nervous system lesions of patients with multiple sclerosis. A single nucleotide polymorphism at position -174 in the IL-6 gene promotor appears to influence IL-6 expression. Recently, several researchers have focused on HLA-DRB alleles, specifically HLA-DRB1*1501, as a potential risk allele in the pathogenesis of multiple sclerosis. Objective: To investigate the possible influence of IL-6/-174 polymorphisms on susceptibility to multiple sclerosis and its integration with HLA-DRB1*1501. Genomic DNA was extracted from whole blood of 345 patients with multiple sclerosis and 426 control subjects. Method: The SSP-PCR method was used to determine genotypes and Fisher’s exact test was applied to determine differences between groups. HLA-DRB1*1501 was observed more frequently among multiple sclerosis patients compared with healthy subjects (45% and 34%, respectively; OR = 1.6, 95% CI = 1.2—2.2, p = 0.0018). At the IL-6/-174 position, the G allele had higher frequency among multiple sclerosis patients compared with controls (77% and 70%, respectively; OR = 1.4, 95% CI = 1.1—1.8, p = 0.0038). This difference was more significant among HLA-DRB1*1501-positive patients and controls (81% and 67%, respectively; OR = 1.9, 95% CI = 1.5—2.5, p < 0.0001). Results: Our results have shown that the G allele at the IL-6/-174 promoter polymorphism may be associated with development of multiple sclerosis in this population, and may be strengthened by HLA-DRB1*1501. Conclusions: We suggest more studies to confirm these results in other populations.


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