An edge-based model for non-Markovian sexually transmitted infections in coupled network

2020 ◽  
Vol 13 (02) ◽  
pp. 2050014
Author(s):  
Xiaofeng Luo ◽  
Junyuan Yang ◽  
Zhen Jin ◽  
Jia Li
Keyword(s):  
Single Layer ◽  
Recovery Process ◽  
Heterosexual Transmission ◽  
Bipartite Networks ◽  
Epidemic Threshold ◽  
Sexually Transmitted ◽  
Epidemic Size ◽  
Recovery Times ◽  
Age Structured ◽  
Edge Based

In this paper, allowing for general transmission and recovery times distributions, we proposed an edge-based age-structured-like compartmental model for STIs (EBACMS) in a coupled network. We considered sexual transmissions between men with also heterosexual contacts. Mathematically, we gave the general approach of proving the nonnegativity of solutions for the system coupling ordinary and partial differential equations, which can be applied to all edge-based compartment models. We then analyzed the epidemic threshold [Formula: see text] with different distributions which couples the thresholds of the single-layer and bipartite networks in the percolation theory. We also studied the global stability of disease-free equilibrium with [Formula: see text] and the final epidemic size [Formula: see text] (the proportion of the population experiencing infection during the epidemic) with [Formula: see text]. In addition, numerical simulations indicated that given a fixed exponential transmission distribution, a higher variance (with same mean) in general recovery distribution gives smaller [Formula: see text] and [Formula: see text]. Sensitivity analysis on [Formula: see text] and [Formula: see text] in terms of the parameters illustrated that male-to-male transmission routes have a greater impact on [Formula: see text] and [Formula: see text] than the heterosexual transmission routes for the Markovian transmission process and arbitrary recovery process. The results provide a good theoretical guideline to consider the distributions of real-world STIs.

Edge-based SEIR dynamics with recovery rate in latent period on complex networks

2020 ◽  
Vol 31 (04) ◽  
pp. 2050057
Author(s):  
Rong Zhou ◽  
Qingchu Wu
Keyword(s):  
Latent Period ◽  
Recovery Rate ◽  
Stochastic Simulations ◽  
Epidemic Threshold ◽  
Seir Model ◽  
Scale Free ◽  
Epidemic Size ◽  
Final Epidemic Size ◽  
Full Analysis ◽  
Edge Based

Disease and information spreading on social and information networks have often been described by ordinary differential equations. A recent research by the authors [Y. Wang et al., Commun. Nonlinear Sci. Numer. Simulat. 45, 35 (2017).] presented an analysis of susceptible-exposed-infected-recovered (SEIR) model with and without infectious force in latent period. We present a full analysis in the more general scenario where the exposed nodes can get vaccinated or recovered. The basic reproduction number and the final epidemic size are theoretically derived. Compared to the standard SEIR model without recovery rate in latent period, our results reveal that both the recovery rate in latent period and the length of latent period can increase the epidemic threshold and inhibit the epidemic outbreak. In addition, the model predictions agree well with the continuous-time stochastic simulations in Erdős–Rényi random graphs and scale-free configuration networks.

scholarly journals Mujeres con VIH-SIDA en el Hospital Nacional Cayetano Heredia en Lima, Perú.

2013 ◽  
Vol 10 (2) ◽  
pp. 62
Author(s):  
Lely SOLARI ZERPA ◽  
Luis Miguel VALDEZ ◽  
Juan ECHEVARRIA ZARATE ◽  
Eduardo GOTUZZO HERENCIA
Keyword(s):  
Hiv Infection ◽  
Drug Users ◽  
Pneumocystis Carinii ◽  
Retrospective Chart Review ◽  
Sexual Practices ◽  
Heterosexual Transmission ◽  
Sexual Life ◽  
Heterosexual Intercourse ◽  
Sexually Transmitted ◽  
Wasting Syndrome

Objective: The aim of this study is to describe the epidemiological and clinical characteristics of the women infected with the Human Inmunodefficiency Virus (HIV) who were seen at the Hospital Nacional Cayetano Heredia from January 1989 to December 1996. Material and Methods: We did a retrospective chart review of their demographic and medical registers. We used the Centres for Disease Control (CDC) classification for the HIV infection. (Stages I-IV). Results: We included 236 women, from 17 to 60 years old, with a mean age of 30.4 years. The number of diagnosed cases per year of infected women increased from 5 in 1989 to 63 in 1996. The probable means of acquisition of infection was heterosexual intercourse in 212 patients (90.2%). Only had one sexual partner in her life 113 (47.8%) of the patients seen. There were 4 (1.6%) sexual workers and there were no intravenous drug users. A percentage of 23.4% have had other Sexually Transmitted Diseases (STD), and these were more prevalent in women who had risky sexual practices (p=0.005). Out of the 236, 69 women had diagnosis of Acquired Inmunodefficiency Syndrome (AIDS) The most frequent AIDS-defining condition was the Wasting Syndrome in 23 women (33.3%). There were 19 deaths within the study period. The mean survival time after the AIDS diagnosis was 10.6 months and the most frequent death cause was Tuberculosis and Pneumocystis carinii Pneumonia. Conclusion: The fact of having a predominantly heterosexual transmission and that there is a high percentage of monogamous women and women with few sexual partners make us suppose that it is probably their partners risk sexual behavior what exposes women to HIV infection. We must underline the importance of an adequate information to women who start their sexual life and of the risks these bring, and the diffusion of the use of condoms to prevent this infection.

scholarly journals Heterosexual Transmission of Human Immunodeficiency Virus Infection – Strategies for Prevention

1991 ◽  
Vol 2 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Brian Conway ◽  
D William Cameron ◽  
Francis A Plummer ◽  
Allan R Ronald
Keyword(s):  
Human Immunodeficiency Virus ◽  
Transmission Rate ◽  
Transmitted Disease ◽  
Immune Deficiency Syndrome ◽  
Educational Interventions ◽  
Sexual Practices ◽  
Heterosexual Transmission ◽  
Sexually Active ◽  
Sexually Transmitted ◽  
Immunodeficiency Virus

In Canada, over 90% of the acquired immune deficiency syndrome cases diagnosed so far have been acquired sexually, with an increasing proportion made up of heterosexual contacts of high risk individuals. In multiple studies, the transmission rate among steady heterosexual partners of infected individuals has been variable. It is likely that complex biological and epidemiological interactions exist between human immunodeficiency virus (HIV) and sexually transmitted diseases with respect to transmission and disease. Other important determinants in transmission of infection may relate to the virus itself. The importance of sexual practices other than vaginal intercourse (such as anal intercourse) in the heterosexual transmission of HIV has not been well studied. The major approach to the control of HIV-associated disease remains the control of primary infection. Sexual practices which are the major epidemiological determinants of HIV transmission can be successfully modified by appropriate educational interventions. The promotion of condom use must form a special part of these interventions. Results of ongoing trials should be available prior to the formulation of recommendations for the use of spermicides. Targeted education programs may allow us to make better use of our resources in a more efficient way. In Canada, groups that could be reached by such programs include: prostitutes and their clients; men and women attending sexually transmitted disease clinics; sexually active women attending family planning clinics; and children and adolescents who are becoming sexually active.

scholarly journals Behaviour change and competitive exclusion can explain the diverging HIV-1 and HIV-2 prevalence trends in Guinea–Bissau

2007 ◽  
Vol 136 (4) ◽  
pp. 551-561 ◽  
Author(s):  
W. P. SCHMIDT ◽  
M. SCHIM VAN DER LOEFF ◽  
P. AABY ◽  
H. WHITTLE ◽  
R. BAKKER ◽  
...  
Keyword(s):  
Competitive Exclusion ◽  
Risk Behaviour ◽  
Epidemiological Data ◽  
Heterosexual Transmission ◽  
Sexual Risk Behaviour ◽  
Sexually Transmitted ◽  
Guinea Bissau ◽  
Prevalence Trends ◽  
Temporary Rise ◽  
Hiv 1

SUMMARYThe aim of this study was to determine whether a temporary rise in sexual risk behaviour during war in Guinea–Bissau could explain the observed trends in HIV-1 and HIV-2 prevalence, and to explore the possible contribution of competitive elimination of HIV-2 by HIV-1. A simulation model of the heterosexual transmission of sexually transmitted infections was parameterized using demographic, behavioural and epidemiological data from rural Guinea–Bissau, and fitted to the observed HIV-1 and HIV-2 trends with and without a historic rise in risk behaviour. The observed trends could only be simulated by assuming a temporary rise in risk behaviour. Around 30% of the projected decline in HIV-2 prevalence from a peak of 8·7% to 4·3% in 2010 was due to competitive elimination by HIV-1. Importantly for public health, HIV-1 prevalence was predicted to continue increasing and to become the dominant HIV type by 2010. Data collection is required to validate this prediction.

scholarly journals On-Field Signs and Symptoms Associated With Recovery Duration After Concussion in High School and College Athletes: A Critically Appraised Topic

2015 ◽  
Vol 24 (1) ◽  
pp. 72-76 ◽  
Author(s):  
Jaebin Shim ◽  
Deanna H. Smith ◽  
Bonnie L. Van Lunen
Keyword(s):  
High School ◽  
College Athletes ◽  
Signs And Symptoms ◽  
Recovery Process ◽  
Return To Play ◽  
Clinical Scenario ◽  
Clinical Question ◽  
Duration Of Symptoms ◽  
Wide Range ◽  
Recovery Times

Clinical Scenario:Over the past decade, sport-related concussions have received increased attention due to their frequency and severity over a wide range of athletics. Clinicians have developed return-to-play protocols to better manage concussions in young athletes; however, a standardized process projecting the length of recovery time after concussion has remained an elusive piece of the puzzle. The recovery times associated with such an injury once diagnosed can last anywhere from 1 wk to several months. Risk factors that could lead to protracted recovery times include a history of 1 or multiple concussions and a greater number, severity, and duration of symptoms after the injury. Examining the possible relationship between on-field or sideline signs and symptoms and recovery times would give clinicians the confident ability to properly treat and manage an athlete’s recovery process in a more systematic manner. Furthermore, identifying factors after a head injury that may be predictive of protracted recovery times would be useful for athletes, parents, and coaches alike.Focused Clinical Question:Which on-field and sideline signs and symptoms affect length of recovery after concussion in high school and college athletes?

Network percolation of the disease transmission based on bipartite networks

2020 ◽  
Vol 34 (06) ◽  
pp. 2050029
Author(s):  
Shuping Li ◽  
Xiaorong Zhao
Keyword(s):  
Disease Transmission ◽  
Random Network ◽  
Distribution Functions ◽  
Cumulative Distribution ◽  
Infectious Period ◽  
Bipartite Networks ◽  
Epidemic Threshold ◽  
Sir Epidemic Model ◽  
Sir Epidemic ◽  
Percolation Network

In this paper, considered heterogeneous infectivity and susceptibility, a general stochastic Susceptible-Infectious-Removed (SIR) epidemic model with the cumulative distribution functions (CDFS) of the infectious contact rate and the infectious period based on bipartite networks is discussed. It is isomorphic to a semidirected random network called the bipartite epidemic percolation network. The epidemic threshold corresponds to the phase transition where a giant strongly connected component appears. It is obtained by using the method of the probability generation function. We show that the critical value of the transmissibility predicted by the bond percolation model is larger than that predicted by the epidemic percolation network. We analyze the influences of the network structure and individual heterogeneity on the epidemic threshold by numerical simulations.

scholarly journals Women, Contraception and STDs Including HIV

1995 ◽  
Vol 6 (6) ◽  
pp. 373-386 ◽  
Author(s):  
E M Carlin ◽  
F C Boag
Keyword(s):  
Hiv Transmission ◽  
Contraceptive Use ◽  
Unwanted Pregnancy ◽  
Transmitted Disease ◽  
Heterosexual Transmission ◽  
Western World ◽  
Sexually Transmitted ◽  
Immunodeficiency Virus ◽  
Hiv Acquisition ◽  
The Relationship

Summary: It is estimated that eight million women are infected with the human immunodeficiency virus (HIV) worldwide. Heterosexual transmission is the predominant mode of HIV transmission on a global basis and is becoming increasingly important in the Western world. Women have long used contraceptives as a means of protection against an unwanted pregnancy, some of which may also protect against sexually transmitted disease (STD) including HIV. We review the relationship between contraceptive methods and STD acquisition and transmission; HIV acquisition and transmission; and the implications of contraceptive use, particularly regarding disease progression, in those women who are already infected with the virus. It is important for all women that protection against both unwanted pregnancy and HIV acquisition and transmission are considered together and not in isolation as nowhere is the argument for a broad based multi-disciplinary approach more cogent.

scholarly journals Gender inequities in sexually transmitted infections: implications for HIV infection and control in Lagos State, Nigeria

2011 ◽  
Vol 3 (1) ◽  
pp. 7 ◽  
Author(s):  
Ezekiel Oluwagbemiga Adeyemi
Keyword(s):  
Focus Group ◽  
Support Groups ◽  
Qualitative Data ◽  
Analytical Techniques ◽  
Sexual Partners ◽  
Heterosexual Transmission ◽  
People Living With Hiv ◽  
Focus Group Discussions ◽  
Group Discussions ◽  
Sexually Transmitted

Beyond the statistics of sex-based differences in infection rates, there are profound differences in the underlying causes and consequences of HIV infections in male and female which need to be examined. The study therefore examines; the gender differences in the STI knowledge and gender-related potential risks of HIV heterosexual transmission. Quantitative and qualitative data were collected. A multi-stage random sampling procedure was employed in administration of 1358 questionnaires. For qualitative data, four focus group discussions (FGD) were conducted to collect information from stakeholders within the study population, while In-depth interview was employed to collect information from 188 people living with HIV/AIDS through support groups in the State. The data collected were subjected to basic demographic analytical techniques. Combination of univariate, bivariate, and multivariate analysis were employed. Information from focus group discussions and in-depth interviews were transcribed and organized under broad headings that depict different aspects of the discussions. Majority of the respondents interviewed did not inform their partners about their infection in the study area. It was also discovered that stigmatization did not allow some women to disclose their status to their sexual partners. Some of the HIV-positive patients interviewed agreed that they did not attend the health facilities to treat the STI’s before they were finally confirmed positive. The study hypothesis revealed that communication between partners about STI’s was associated with an increase in risk reduction behaviour. The paper concluded that there is need for more information and education on communication about STI’s between the sexual partners; to reduce the spread of sexually transmitted diseases within the nation.

Rehabilitation and recovery times for canine patients post hemilaminectomy

2020 ◽  
Vol 11 (9) ◽  
pp. 422-425
Author(s):  
Katherine Vine
Keyword(s):  
Intervertebral Disc ◽  
Patient Outcomes ◽  
Recovery Process ◽  
Human Medicine ◽  
Intervertebral Disc Disease ◽  
Disc Disease ◽  
Postoperative Rehabilitation ◽  
Recovery Times ◽  
Crucial Part

The recovery of ambulation is a crucial part of the recovery process for canine patients with intervertebral disc disease undergoing a hemilaminectomy. Although ambulation is accomplished in most cases, many are left with deficits in strength and coordination. Human medicine suggests that postoperative rehabilitation improves patient outcomes; it is therefore useful to examine whether the same would be true for canine patients. Additionally, as veterinary nurses it is important to understand why certain rehabilitative procedures are being performed for spinal patients, and whether those procedures actually help the patient to recover.

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