scholarly journals Sex-Specific Asymmetrical Attack Rates in Combined Sexual-Vectorial Transmission Epidemics

2019 ◽  
Vol 7 (4) ◽  
pp. 112
Author(s):  
Ana Carolina W. G. de Barros ◽  
Kaline G. Santos ◽  
Eduardo Massad ◽  
Flávio Codeço Coelho
Keyword(s):  
Mathematical Model ◽  
Bayesian Inference ◽  
South America ◽  
Sexual Transmission ◽  
Sexual Contact ◽  
Sexual Partners ◽  
Transmission Route ◽  
Increased Risk ◽  
Using Data ◽  
Male To Female

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.

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
Keyword(s):  
Mathematical Model ◽  
Central Nervous System ◽  
Sexual Transmission ◽  
Sexual Contact ◽  
Transmission Route ◽  
Increased Risk ◽  
Route Of Transmission ◽  
The Central Nervous System ◽  
The Impact ◽  
Male To Female

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.

Gonorrhea in Preadolescent Children: An Inquiry Into Source of Infection and Mode of Transmission

PEDIATRICS ◽  
1977 ◽  
Vol 60 (2) ◽  
pp. 153-156 ◽  
Author(s):  
David S. Folland ◽  
Ralph E. Burke ◽  
Alan R. Hinman ◽  
William Schaffner
Keyword(s):  
Child Neglect ◽  
Sexual Transmission ◽  
Clinical Manifestations ◽  
Positive Culture ◽  
Sexual Contact ◽  
Gonococcal Infection ◽  
Vaginal Infection ◽  
Source Of Infection ◽  
Increased Risk ◽  
History Of

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.

scholarly journals The potential for sexual transmission to compromise control of Ebola virus outbreaks

2016 ◽  
Vol 12 (6) ◽  
pp. 20151079 ◽  
Author(s):  
John E. Vinson ◽  
John M. Drake ◽  
Pejman Rohani ◽  
Andrew W. Park
Keyword(s):  
Mathematical Model ◽  
Ebola Virus ◽  
Transmission Rate ◽  
Sexual Transmission ◽  
Sexual Contact ◽  
West African ◽  
Simple Mathematical Model ◽  
Initial Infection ◽  
Epidemic Dynamics ◽  
Contact Transmission

Recent evidence suggests that sexual contact may give rise to transmission of Ebola virus long after infection has been cleared from blood. We develop a simple mathematical model that incorporates contact transmission and sexual transmission parametrized from data relating to the 2013–2015 West African Ebola epidemic. The model explores scenarios where contact transmission is reduced following infection events, capturing behaviour change, and quantifies how these actions reducing transmission may be compromised by sexual transmission in terms of increasing likelihood, size and duration of outbreaks. We characterize the extent to which sexual transmission operates in terms of the probability of initial infection resolving to sexual infectiousness and the sexual transmission rate, and relate these parameters to the overall case burden. We find that sexual transmission can have large effects on epidemic dynamics (increasing attack ratios from 25% in scenarios without sexual transmission but with contact-transmission-reducing behaviour, up to 80% in equivalent scenarios with sexual transmission).

scholarly journals Factors Associated With HIV Testing Among Atlanta's Homeless Youth

2020 ◽  
Vol 32 (4) ◽  
pp. 325-336
Author(s):  
Ranell L. Myles ◽  
Janae Best ◽  
Greg Bautista ◽  
Eric R. Wright ◽  
Ana LaBoy ◽  
...  
Keyword(s):  
Hiv Testing ◽  
Risk Behaviors ◽  
Homeless Youth ◽  
Sexual Partners ◽  
Transactional Sex ◽  
Sexually Active ◽  
High Risk Behaviors ◽  
Factors Associated ◽  
Increased Risk ◽  
Using Data

Homeless youth experience increased risk of contracting HIV, making HIV testing imperative in this population. We analyzed factors associated with HIV testing among homeless youth in Atlanta, Georgia using data from the 2015 Atlanta Youth Count and Needs Assessment. The analysis included 693 homeless youth aged 14–25 years, of whom 88.4% reported ever being tested for HIV, and 74.6% reported being tested within the previous year. Prevalence of ever testing for HIV was significantly higher among youth who reported risk factors for HIV (sexually active, transactional sex, or ever having an STI). Higher prevalence of testing within the last year was significantly associated with experiencing physical abuse or transactional sex. However, reporting ≥ 4 sexual partners or not using condoms were not associated with higher testing. Although testing prevalence among homeless youth was high, homeless youth engaging in certain high risk behaviors could benefit from further promotion of HIV testing.

scholarly journals Prevalence of gonorrhea and chlamydia in a community clinic for men who have sex with men in Lisbon, Portugal

2019 ◽  
Vol 30 (10) ◽  
pp. 951-959 ◽  
Author(s):  
Sofia Ribeiro ◽  
Diogo de Sousa ◽  
Diogo Medina ◽  
Rita Castro ◽  
Ângela Lopes ◽  
...  
Keyword(s):  
Cross Sectional Study ◽  
Sexual Partners ◽  
Foreign Born ◽  
Inhaled Drugs ◽  
Cross Sectional ◽  
Sexually Transmitted ◽  
Increased Risk ◽  
Sex With Men ◽  
Using Data ◽  
Associated Risk Factors

Men who have sex with men (MSM) are at greater risk for sexually transmitted infections (STIs). Data on MSM chlamydia and gonorrhea prevalence estimates and associated risk factors are scarce. To our knowledge, this is the first study to describe the prevalence and the determinants of both chlamydia and gonorrhea infections in MSM in Portugal. We conducted a cross-sectional study using data from 1832 visits to CheckpointLX, a community-based center for screening blood-borne viruses and other STIs in MSM. Overall prevalence of chlamydia or gonorrhea in our sample was 16.05%, with 14.23% coinfection and 40.73% asymptomatic presentation among those testing positive. Anorectal infection was most common for chlamydia (67.26%), followed by urethral (24.78%) and oral (19.47%) infection. Oral infection was most common for gonorrhea (55.63%), followed by anal (51.25%) and urethral (17.50%) infection. In multivariate analyses, young age ( U = 94684, p = 0.014), being foreign-born (χ2 = 11.724, p = 0.003), reporting STI symptoms (χ2 = 5.316, p = 0.021), inhaled drug use (χ2 = 4.278, p = 0.039) and having a higher number of concurrent (χ2 = 18.769, p < 0.001) or total (χ2 = 5.988, p = 0.050) sexual partners were each associated with higher rates of chlamydia or gonorrhea infection. Young and migrant MSM are a vulnerable population to STIs, as are those who use inhaled drugs and those with a higher number of concurrent or total sexual partners. Although Portugal has no guidelines on chlamydia and gonorrhea screening, our results point toward a need for greater awareness about the importance of high-frequency screening for those at increased risk (i.e., every three to six months).

Male-to-Female Transmission of Toxoplasmosis Between Sexual Partners

2019 ◽  
Author(s):  
Jana Hlaváčová ◽  
Jaroslav Flegr ◽  
Karel Řežábek ◽  
Pavel Calda ◽  
Šárka Kaňková
Keyword(s):  
Sexual Partners ◽  
Male To Female

Sibling Alcohol Use Disorder Is Associated With Increased Risk for Suicide Attempt

2021 ◽  
pp. 216770262110250
Author(s):  
Mallory E. Stephenson ◽  
Sara Larsson Lönn ◽  
Jessica E. Salvatore ◽  
Jan Sundquist ◽  
Kenneth S. Kendler ◽  
...  
Keyword(s):  
Alcohol Use ◽  
Suicide Attempt ◽  
Alcohol Use Disorder ◽  
Cox Regression ◽  
Population Based ◽  
Swedish Population ◽  
Sibling Pairs ◽  
Increased Risk ◽  
Using Data ◽  
Shared Genetic

The association between having a sibling diagnosed with alcohol use disorder (AUD) and risk for suicide attempt may be attributable to shared genetic liability between AUD and suicidal behavior, effects of environmental exposure to a sibling’s AUD, or both. To distinguish between these alternatives, we conducted a series of Cox regression models using data derived from Swedish population-based registers with national coverage. Among full sibling pairs (656,807 males and 607,096 females), we found that, even after we accounted for the proband’s AUD status, the proband’s risk for suicide attempt was significantly elevated when the proband’s sibling was affected by AUD. Furthermore, the proband’s risk for suicide attempt was consistently higher when the sibling’s AUD registration had occurred more recently. Our findings provide evidence for exposure to sibling AUD as an environmental risk factor for suicide attempt and suggest that clinical outreach may be warranted following a sibling’s diagnosis with AUD.

Prognostic role of Krebs von den Lungen-6 (KL-6) measurement in idiopathic pulmonary fibrosis: a systematic review and meta-analysis

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Elena Aloisio ◽  
Federica Braga ◽  
Chiara Puricelli ◽  
Mauro Panteghini
Keyword(s):  
Systematic Review ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Binary Data ◽  
Meta Analysis ◽  
Mortality Prediction ◽  
Asian Populations ◽  
Increased Risk ◽  
Using Data ◽  
Patient Prognosis

Abstract Objectives Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial disease with limited therapeutic options. The measurement of Krebs von den Lungen-6 (KL-6) glycoprotein has been proposed for evaluating the risk of IPF progression and predicting patient prognosis, but the robustness of available evidence is unclear. Methods We searched Medline and Embase databases for peer-reviewed literature from inception to April 2020. Original articles investigating KL-6 as prognostic marker for IPF were retrieved. Considered outcomes were the risk of developing acute exacerbation (AE) and patient survival. Meta-analysis of selected studies was conducted, and quantitative data were uniformed as odds ratio (OR) or hazard ratio (HR) estimates, with corresponding 95% confidence intervals (CI). Results Twenty-six studies were included in the systematic review and 14 were finally meta-analysed. For AE development, the pooled OR (seven studies) for KL-6 was 2.72 (CI 1.22–6.06; p=0.015). However, a high degree of heterogeneity (I2=85.6%) was found among selected studies. Using data from three studies reporting binary data, a pooled sensitivity of 72% (CI 60–82%) and a specificity of 60% (CI 52–68%) were found for KL-6 measurement in detecting insurgence of AE in IPF patients. Pooled HR (seven studies) for mortality prediction was 1.009 (CI 0.983–1.036; p=0.505). Conclusions Although our meta-analysis suggested that IPF patients with increased KL-6 concentrations had a significant increased risk of developing AE, the detection power of the evaluated biomarker is limited. Furthermore, no relationship between biomarker concentrations and mortality was found. Caution is also needed when extending obtained results to non-Asian populations.

scholarly journals A Mathematical Model of Contact Tracing during the 2014–2016 West African Ebola Outbreak

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 608
Author(s):  
Danielle Burton ◽  
Suzanne Lenhart ◽  
Christina J. Edholm ◽  
Benjamin Levy ◽  
Michael L. Washington ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Disease Management ◽  
Ebola Virus ◽  
Virus Disease ◽  
Infected Individual ◽  
Vital Role ◽  
West African ◽  
Contact Tracing ◽  
The Novel ◽  
Using Data

The 2014–2016 West African outbreak of Ebola Virus Disease (EVD) was the largest and most deadly to date. Contact tracing, following up those who may have been infected through contact with an infected individual to prevent secondary spread, plays a vital role in controlling such outbreaks. Our aim in this work was to mechanistically represent the contact tracing process to illustrate potential areas of improvement in managing contact tracing efforts. We also explored the role contact tracing played in eventually ending the outbreak. We present a system of ordinary differential equations to model contact tracing in Sierra Leonne during the outbreak. Using data on cumulative cases and deaths, we estimate most of the parameters in our model. We include the novel features of counting the total number of people being traced and tying this directly to the number of tracers doing this work. Our work highlights the importance of incorporating changing behavior into one’s model as needed when indicated by the data and reported trends. Our results show that a larger contact tracing program would have reduced the death toll of the outbreak. Counting the total number of people being traced and including changes in behavior in our model led to better understanding of disease management.

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