Ebola Virus Disease transmission
EVD outbreaks are spread through direct contact with infected animals or bodily fluids, and the chain of transmission from humans is driven by direct contact with blood or other bodily fluids from patients. People who have direct contact with infected people or their blood and body fluids, such as health workers without wearing protective equipment.
The study reported the finding that all or most of the secondary transmissions involved direct physical contact with Ebola sufferers. Several studies have also shown that people who are in the same house but do not have direct contact with Ebola sufferers will not be exposed to the Ebola virus because this virus does not spread through the air.
The risk of transmitting EVD from direct skin contact with EVD patients is lower than the risk from exposure to blood or body fluids and may be more predisposed to severe disease. It is not known whether transmission from direct skin contact is mediated by the Ebola virus. Direct exposure to blood and body fluids has also been implicated in EVD transmission but is uncommon.
Ebola Virus Disease Laboratory Research
Ebola virus is usually detected in a patient’s blood at the time of fever and initial symptoms appear, although the level of Ebola RNA virus at the time of fever and initial symptoms is usually low and in some patients it may not be detected during the first 3 days of illness.
Apart from blood, EVD patients are acute and cured. In a study involving both acute and recovering phases of illness, ebola RNA virus was detected in the patient’s saliva, skin, breast milk, stool, tears, and sperm, but not so much in the patient’s urine, vomiting or sweat. However, maintaining contact with Ebola sufferers is very important as the main prevention.
In a different study that focused on the healing phase of the disease, the Ebola virus was detected from female genitalia, rectum, and seminal fluid from 1 or more EVD of patients with RT-PCR, but not in urine or saliva. In another study involving 28 patients recovered from EVD, all specimens other than semen obtained between 12 and 157 days after negative symptoms by viral culture and by viral antigen testing included 85 tear specimens, 84 sweat, 79 stool, 95 urine, 86 of saliva, and 44 from sweat.
Ebola virus has been detected for up to 101 days after the onset of symptoms in sperm, 33 days from female genital fluid, 29 days from rectum, 23 days from urine, 21 days in blood, 15 days in breast milk, eight days in saliva, and six days. on the skin.
Although the Ebola virus has been detected in breast milk, the information is based on a single patient and there is insufficient information to provide guidance on the safe amount of time after illness for an infant to continue breastfeeding. Although some studies have shown that the Ebola virus can survive in sperm longer than blood or other body fluids.
Ebola Virus Disease transmission
EVD is highly contagious in critically ill patients and patients who have died. On 6 October 2014, in Spain it was announced that an additional nurse was diagnosed with EVD after treating an EVD patient (who died) in the hospital. In the same country, Spanish investigations are ongoing to determine exactly how nurses get EVD and how this type of exposure can be prevented.
Airborne transmission of the Ebola virus has been hypothesized but has not been demonstrated in humans. While the Ebola virus can be transmitted via airborne particles under experimental conditions in animals, this strain has not been documented during outbreaks of human EVD in hospital-like settings.
In the laboratory, premate animals with their heads placed in a closed area have been exposed to and infected by the nebulized aerosol Ebola virus. In fact, in a different experiment, monkeys were placed in a cage 3 meters from the monkey cage that were intramuscularly inoculated with Ebola. (Read: Should You Worry About Your Pet Has Ebola? )
The study concluded that “fomite and droplet contact” transmission to control monkeys was unlikely. Likewise, the Reston virus outbreak (a species of the Reston ebolavirus, which does not cause EVD in humans). Infection occurs in non-human primates in separate cages and the route of transmission cannot be confirmed for all infected primates.
Even some animal handlers developed antibody responses to the Reston virus indicating asymptomatic infection that occurs in humans by direct contact and involves animal handling transmission between primates.
A more recent trial specifically designed to further evaluate the likelihood of naturally occurring airborne transmission of the Ebola virus among primates did not demonstrate transmission of the Ebola virus from infection.
In investigations of the Ebola outbreak, some EVD patients have not reported contact with other EVD patients, leading to speculation regarding transmission via aerosol virus particles. All 74 patients with EVD confirmed by RT-PCR testing or the Ebola antibody or antigen detection test in the Ebola outbreak had a high risk exposure to Ebola. Similarly, in the 2007–2008 Uganda outbreak of Ebola, although some possibly not virologically confirmed cases had no reported contact exposure, 42 laboratory-confirmed cases had contact with EVD.
Ebola Virus Disease Outbreak
Most of the evidence regarding human-to-human transmission of the Ebola virus comes from previous Ebola outbreak investigations. Although the current EVD epidemic in West Africa is unprecedented on the scale of the clinical course of infection for example, at the incubation period, the duration of disease and the transmissibility of the virus are the baseline reproductive size estimates. As has been observed in previous Ebola outbreaks, the genome sequence of EVD outbreaks has a small number of distinct genetic changes, but it is not known whether these changes impact disease severity or transmissibility.
EVD between healthcare personnel and others relates to direct contact with an infected person and direct contact with bodily fluids from an EVD patient. Infection control, including recommendations for standards, contact, and precautions for general care, reflects the routes established for transmission from humans to human EVD and is based on data collected from previous EVD outbreaks in Africa in addition to experimental data. Airborne transmission of EVD between humans has not been demonstrated in investigations that have described human-to-human transmission.