Viral Haemorrhagic Fever
In Africa, transmission of VHF has been associated with the reuse of unsterile needles and syringes and inadequate barrier nursing procedures for blood, other body fluids, secretions and excretions. The risks associated with various body fluids have not been well defined as most caregivers who acquired infection had multiple contacts with multiple fluids. The exact risk of airborne transmission is uncertain but must be very low, since to date, no cases of airborne infection involving humans had been documented. However this must be considered to be a possibility especially in patients with advanced stages of disease. Moreover, airborne transmission of VHF had been demonstrated in monkeys. The risk of person-to-person transmission is highest in the latter stages of the illness, which are characterized by vomiting, diarrhoea, shock, and haemorrhage. VHF infection has not been reported in persons whose contact occurred during the incubation period, the incubation period generally ranging from 2 days to 3 weeks.
The WHO made recommendations in September 1995 for management of suspected cases of viral haemorrhagic fever. These recommendations apply to patients who, within 3 weeks before the onset of fever, either (1) traveled in the specific local area of a country where VHF has recently occurred, (2) those who had direct contact with the blood, other body fluids, secretions or excretions of a patient or animal with VHF, (3) worked in a laboratory or animal facility that handles haemorrhagic fever viruses. The likelihood of acquiring VHF is considered to be extremely low in persons who do not meet any of the criteria.
Standard precautions are generally sufficient for patients in the early stages of the disease undergoing evaluation, since they are unlikely to have symptoms such as vomiting, diarrhoea, and haemorrhage which increases the risk of person-to-person transmission. If the patient has respiratory symptoms such as cough, then face shields or masks, and eye protection (goggles or eyeglass with sideshields) should be worn by caregivers.
The patient should be placed in a private room. A negative pressure room is not required during the early stages of the illness. Non-essential staff and visitors should be restricted from entering the room. Caretakers should use barrier precautions to prevent skin or mucous membrane exposure to blood and other body fluids. Gloves and gowns should be worn by all persons entering the room. In addition, face masks and shields should be worn by all persons coming within 1 metre of the patient to prevent contact with blood, other body fluids, secretions and excretions. Foot protection may be advised if there is copious amount of blood, vomit, or faeces present in the environment.
Patients with suspected VHF who have a prominent cough, vomiting, diarrhoea, or haemorrhage should be placed in a negative-pressure room in order to prevent possible exposure to airborne particles. Persons entering the room should wear personal protective respirators.
Measure to prevent precutaneous injuries should be emphasized.
Laboratory testing should be kept to a minimum. Specimens should be put in durable leak-proof containers which are then placed in plastic bags. The laboratory staff should be alerted and the transport of the specimen to the laboratory should be carried out by a single person. Specimens used in laboratory tests should be pre-treated with 10ul per ml of blood with PEG (10% Triton X-100). Specimens in clinical laboratory may be handled in a class II biological safety cabinet. Virus isolation must be done at biosafety level 4.
Contaminated surfaces or objects may be disinfected using standard procedures with bleach or other usual hospital disinfectants active against enveloped viruses.
Soiled linen should be placed in clearly labelled leak-proof bags and transported directly to a decontamination area. Decontamination may be done by autoclave or even incinerated. However, linens can be laundered using a normal hot water cycle with bleach if universal precautions to prevent exposure are precisely followed.
Although there is no evidence for transmission of VHF to humans through exposure to contaminated sewage, the following measures should be followed to reduce the risk. Blood, suctioned fluids, secretions and excretions should be treated before disposal either by autoclave, treated in a chemical toilet, or disinfected with household bleach for at least 5 minutes before flushing or disposal.
Solid clinical wastes, including needles, syringes, and tubings, should either be incinerated, or preferably autoclaved before incineration. They can also be disinfected by a disinfectant before disposed of according to local regulations.
If the patient dies, than handling of the body should be kept down to a minimum. The corpse should not be embalmed but wrapped in a sealed leak-proof material. Cremation is recommended but if burial is used, then a sealed casket is recommended. Autopsies should not be carried out unless strictly necessary. If carried out, then special containment precautions must be followed.
Persons with percutaneous or mucocutaneous exposures to blood, body fluids, secretions, and excretions should immediately wash Autopsies should not be carried out unless strictly necessary. If carried out, then special containment precautions must be followed.
Persons with percutaneous or mucocutaneous exposures to blood, body fluids, secretions, and excretions should immediately wash the affected surface with soap and water. Mucous membranes such as the eye should be irrigated. Exposed persons should receive medical evaluation and follow-up management.