Background: Sexual transmission of Ebola virus disease (EVD) 6 months after onset of symptoms has been recently documented, and Ebola virus RNA has been detected in semen of survivors up to 9 months after onset of symptoms. As countries affected by the 2013-2015 epidemic in West Africa, by far the largest to date, are declared free of Ebola virus disease (EVD), it remains unclear what threat is posed by rare sexual transmission events that could arise from survivors.
Methodology/principal Findings: We devised a compartmental mathematical model that includes sexual transmission from convalescent survivors: a SEICR (susceptible-exposed-infectious-convalescent-recovered) transmission model. We fitted the model to weekly incidence of EVD cases from the 2014-2015 epidemic in Sierra Leone. Sensitivity analyses and Monte Carlo simulations showed that a 0.1% per sex act transmission probability and a 3-month convalescent period (the two key unknown parameters of sexual transmission) create very few additional cases, but would extend the epidemic by 83 days [95% CI: 68-98 days] (p < 0.0001) on average. Strikingly, a 6-month convalescent period extended the average epidemic by 540 days (95% CI: 508-572 days), doubling the current length, despite an insignificant rise in the number of new cases generated.
Conclusions/significance: Our results show that reductions in the per sex act transmission probability via abstinence and condom use should reduce the number of sporadic sexual transmission events, but will not significantly reduce the epidemic size and may only minimally shorten the length of time the public health community must maintain response preparedness. While the number of infectious survivors is expected to greatly decline over the coming months, our results show that transmission events may still be expected for quite some time as each event results in a new potential cluster of non-sexual transmission. Precise measurement of the convalescent period is thus important for planning ongoing surveillance efforts.
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http://dx.doi.org/10.1371/journal.pntd.0004676 | DOI Listing |
Open Vet J
November 2024
Research Center for Preclinical and Clinical Medicine, National Research and Innovation Agency (BRIN), Bogor, Indonesia.
Bovine trichomoniasis is a reproductive illness that affects cattle causing pyometra, early to mid-pregnancy miscarriages, and lower birth rates. is a flagellated protozoan which first discovered in France in 1888 and composts three phases during its lifecycle including trophozoite, cyst, and pseudocyst. In addition, several factors contributed to the prevalence of trichomoniasis and fall into three categories are management, cow, and bull-related factors.
View Article and Find Full Text PDFJ West Afr Coll Surg
October 2024
Adeoyo Maternity Teaching Hospital, Ibadan, Nigeria.
Background: Human immunodeficiency virus (HIV) is a lentivirus. It is transmitted through sexual intercourse, shared intravenous drugs, contaminated needle use, blood transfusion, and mother-to-child transmission. Of the patients with HIV, 50%-75% have ocular manifestations and this may be the primary presentation.
View Article and Find Full Text PDFSci Rep
December 2024
School of Public Health, Heinz Mehlhorn Academician Workstation, Hainan Medical University, Haikou, 571199, Hainan, China.
Globally, people living with HIV (PLHIV) are at a high risk of syphilis transmission, and Hainan Province has one of the highest syphilis rates in China. However, there is no targeted syphilis screening for HIV patients in Hainan, highlighting the need for data to guide public health interventions. This study aims to assess the incidence of seropositive syphilis and its associated factors among PLHIV.
View Article and Find Full Text PDFSci Rep
December 2024
Center for Global Health and Inter-Disciplinary Research, College of Public Health, University of South Florida, Tampa, FL, USA.
Successful transmission of Plasmodium falciparum from one person to another relies on the complete intraerythrocytic development of non-pathogenic sexual gametocytes infectious for anopheline mosquitoes. Understanding the genetic factors that regulate gametocyte development is vital for identifying transmission-blocking targets in the malaria parasite life cycle. Toward this end, we conducted a forward genetic study to characterize the development of gametocytes from sexual commitment to mature stage V.
View Article and Find Full Text PDFPLoS Pathog
December 2024
Amsterdam UMC, location University of Amsterdam, Experimental Immunology, Amsterdam, The Netherlands.
The gastrointestinal tract is a prominent portal of entry for HIV-1 during sexual or perinatal transmission, as well as a major site of HIV-1 persistence and replication. Elucidation of underlying mechanisms of intestinal HIV-1 infection are thus needed for the advancement of HIV-1 curative therapies. Here, we present a human 2D intestinal immuno-organoid system to model HIV-1 disease that recapitulates tissue compartmentalization and epithelial-immune cellular interactions.
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