6. MANAGEMENT OF VHF PATIENTS
6.1 Medical management of VHF patients
The medical management of VHF patients is a subject on which it is difficult to obtain consensus of opinion, and detailed analysis lies beyond the scope of the present document. The following remarks represent an attempt to summarize experience gained mainly in the management of Congo fever patients in South Africa.
6.1.1 Antiviral therapy
Ribavirin is a synthetic nucleoside analogue, which has been shown to be of use in treating hantavirus and arenavirus (Lassa fever) infections. There is evidence to suggest that it is of benefit in treating Congo fever patients but the findings are not conclusive, mainly because too few patients have been placed on therapy sufficiently early in the course of the disease for meaningful analysis: since deaths occur from day 5 of illness onwards the disease must be recognized and treated early.
In practice, ribavirin therapy has only been attempted in patients with severe disease and a poor prognosis. In order to reach an early decision to institute therapy, it should be noted that during the first 5 days of illness in Congo fever any of the following pathological values are predictive of fatal outcome: leucocyte count ≥10x109/L; platelet count ≤20x109/L; AST ≥200U/L; ALT ≥150U/L; APTT ≥60 seconds; and fibrinogen ≤110mg/dL. After day 5 of illness any value may be grossly abnormal without necessarily being indicative of a poor prognosis.
The oral preparation of ribavirin is registered in South Africa for the treatment of viral hepatitis. The drug would therefore be used ‘off- label’ for the treatment of CHF or Lassa fever. The trade name is Copegus, a Roche product, available in 200mg tablets. Ideally all severely ill patients should be treated with the intravenous formulation of ribavirin, but unfortunately it is not currently available in South Africa. It generally has to be sourced and imported when required. Table 6.1 and 6.2 shows the recommended dosage for adults and children.
Oral ribavirin treatment of CCHF reported by Fisher-Hoch et al. (14): 4000 mg/d d1-4, 2400 mg/d d5-10.
Ribavirin can cause bone marrow depression, raised serum bilirubin values, nausea and malaise, but these effects are generally overshadowed by the signs and symptoms of VHF. Moreover, the drug is teratogenic in animal models, but its use should still be considered in pregnant patients given the potential for lethality in severe infections.
Congo fever patients have generally succumbed or recovered before completion of 10 days of treatment, resulting in early termination of the treatment.
No other chemotherapeutics are available for the treatment of VHFs, and the use of ribavirin is indicated only for the treatment of hantavirus, arenavirus and Congo fever virus infections. Use of ribavirin is considered to be contraindicated in Rift Valley fever as some patients treated in Saudi Arabia in 2000 succumbed to late-onset viral encephalitis, but the association with ribavirin is not clear.
Prophylactic use of ribavirin
Oral ribavirin has been used prophylactically in persons deemed to have been exposed to infection with hantaviruses, arenaviruses and Congo fever virus, but the side effects of the drug can cause confusing and distressing illness which is particularly inconvenient when several people are affected. Hence it is advised that prophylaxis should be strictly limited to instances where there are strong indications that there has been exposure to infection, such as needle stick with blood known to be infected. The dosage for prophylaxis is the same as for treatment of infection.
It has been demonstrated that interferons have significant antiviral activitiy against VHF agents in vitro and in animal models, and that there may be high levels of interferon expression in VHF patients. There appears to be no information on the value of interferon therapy in VHFs, but it is cautioned that its use in VHF patients poses difficult clinical challenges.
6.1.2 Immune plasma therapy
There is no controlled experimental evidence to indicate that the use of immune plasma is of benefit in VHF, and persons who have recovered from Congo fever generally have low neutralizing antibody activity in their serum which is unlikely to be of therapeutic value.
6.1.3 Supportive treatment
Monitoring of vital functions
This should include temperature, pulse and respiration rates, chest auscultation and fluid balance (liquid intake/urinary output). The necessity for and frequency of additional monitoring is dictated by the severity of the disease/condition of the patient and whether or not a ventilator and drugs such as diuretics are being used. Laboratory tests to support patient management include full blood counts (with platelet plus haemoglobin values), coagulation, liver function, glucose, creatinine, urea, electrolyte, blood gases and pH determinations on appropriate blood samples.
A chest X-ray should be taken on admittance of the patient and repeated if respiratory distress or suspected secondary infection occurs.
This may be considered when blood haemoglobin levels fall to 8-10g/dL, but some patients tolerate such low levels quite well, and it is more important to treat on the basis of signs and symptoms of anaemia (respiratory distress) than purely on haemoglobin levels.
Although fresh blood may be transfused, it is better to use red blood cell concentrate to treat the anaemia of VHF. This helps prevent fluid overload and development of the respiratory distress syndrome. Modern additives to red cell concentrates adequately maintain the levels of phosphates which modulate the oxygen affinity of haemoglobin, so it is not essential to use fresh blood. As a rough guide, one unit of red cell concentrate should raise the haemoglobin level of an average adult by lg/dL.
Treatment of disseminated intravascular coagulopathy (DIC)
Contrary to our earlier perceptions, DIC appears to be an early and prominent feature of CCHF and other VHFs. There are two views on treatment of DIC: one holds that the administration of coagulation factors merely ‘adds fuel to the fire’, while the other advocates judicious replacement of coagulation factors. The latter opinion appears to be most widely favoured.
The use of heparin is considered to be useful in the early hypercoaguable stage of DIC, when there is accelerated partial thromboplastin time (PTT) and decreased prothrombin ratio (PR), but is of no value once the fibrinogen level falls. However, most cases of VHF are not diagnosed sufficiently early for use of heparin to be of value. Moreover, the use of the drug requires constant monitoring of the response and is best avoided by the inexperienced.
Thrombocytopaenia is a common feature of VHFs and occurs regularly in CCHF. There is agreement on the need for replacement of platelets, but this should be done only if thrombocytopaenia is accompanied by purpura and active bleeding such as epistaxis, or if platelet counts fall below 20x109/L.
A bag of platelet concentrate contains approximately 0.5 - 1.0X10 11 platelets in about 50 ml of plasma. The dosage of platelet concentrate is 1 bag/10kg body mass and transfusion services can be requested to pool the total dose, e.g. 7 bags can be supplied as 1 bag of 350 ml, which can be administered rapidly (10 minutes). Transfusion services ordinarily supply platelets of appropriate ABO group specificity. The treatment may be repeated over a period of days if the patient's platelet level continues to decline or remains critically low.
If there is manifest consumption of other coagulation factors (abnormal PTT and PR levels, fibrinogen level <0.8g/L), administer fresh frozen plasma (FFP) or fresh dried plasma (FDP)at the rate of 10ml/kg body mass for the first dose. The treatment may be repeated if the patient continues to bleed or if coagulation factor levels remain markedly abnormal. As a general rule, 2-3 units of FFP or FDP should be administered to augment coagulation factors for every 10 units of red cell concentrate given to the patient.
Fibrinogen is not available as a separate product, but apart from its administration in FFP and FDP, it (and other factors) can also be administered in the form of cryoprecipitate. One bag of wet cryoprecipitate contains about 250 mg of fibrinogen and a bottle of dried cryoprecipitate, called anti-haemophilia factor (AHF), which is derived from a pool of 4-6 units of wet cryoprecipitate, contains approximately 1 g of fibrinogen. About 1-2 g fibrinogen (10 bags of wet cryoprecipitate) may be administered as a first dose.
Prothrombin complex concentrate (PCC, factor IX complex, Proplex) may be indicated following liver damage. It contains 200 units factor IX in a10 ml volume and a dose of 1 U/kg should increase the blood level of the factor by approximately 1%. Vitamin K should also be administered.
Plasma is used to replace coagulation factors, not merely for volume expansion, but it is expensive and haemodynamic goals can be achieved with artificial colloids or even crystalloids. Iso-osmotic albumin solution (4%) may be used for volume expansion. Although
20% albumin has been used to treat hypoproteinaemia following liver damage in CCHF, it is considered better to use an enteral feed that provides sufficient calories and protein according to body mass. If the gut is unavailable for enteral nutrition parenteral feeding may be necessary.
Hypoglycaemia was thought to be of critical importance in a number of CCHF patients in South Africa and blood glucose levels should be monitored carefully in severely ill patients.
There is no information on the effectiveness of steroids to allay the ‘cytokine storm’ underlying the DIC in VHF patients, but there is some support for this approach from animal models. If used, the dose should not exceed 200-300mg hydrocortisone daily. The use of non-steroidal anti-inflammatory drugs is not recommended.
Antacids, painkillers, relaxants and tranquillisers are administered as indicated.
Antibiotic prophylaxis is generally not indicated, however many patients will have received antibiotics prior to the diagnosis having been made. As with all patients in the ICU regular screening for colonization and infection is necessary.
Counselling of patients and relatives is mandatory as this is a highly stressful situation.
6.2 Clinical pathology monitoring of VHF patients
Hospitals which manage suspected or confirmed cases of VHF should have available the services of a laboratory able to conduct the following tests:
● A minimum range of screening tests to eliminate non-VHF diseases:
§ Full blood count.
§ Examination of blood smears for parasites and bacteria.
§ Blood cultures for septicaemia.
● Haematological and clinical chemistry tests to monitor treatment and progress of patients:
§ Full blood counts (including platelet and haemoglobin values).
§ Coagulation studies.
§ Liver function tests.
§ Blood glucose tests.
§ Creatinine, urea, electrolyte determinations.
§ Blood gases and pH determinations.
§ Cross matching studies for transfusions.
Ideally the tests should be conducted by a small team of experienced volunteer technologists in a room set aside for the purpose within an existing laboratory, but since the occurrence of VHF is sporadic the expenditure to equip a dedicated unit is not justified. Consequently, the required tests are often conducted within routine laboratory facilities temporarily set aside for the purpose as required.
Technologists who conduct clinical pathology tests on specimens from VHF patients should be trained in the donning, removal, and disposal of personal protective equipment (PPE), and entry and exit procedures from infected areas, as described under isolation precautions for VHF patients (see section 6,3).
Only volunteer team members should be present during the testing of specimens from suspected or confirmed VHF patients, and as far as possible manipulation of specimens should be performed in biohazard laminar flow safety cabinets (class IIA).
Duty registers should be kept, with staff subjected to the same monitoring as other medical personnel dealing with VHF patients, and incidents constituting potential exposure to infection, including injuries and spillages, should be dealt with as described in sections 6.4 and 7.
Decontamination of laboratory equipment including auto analyzers should follow standard operating procedures developed from manufacturer’s instructions.
Decontamination of laboratory floors, walls and work surfaces, and disposal of waste materials, should follow procedures described in section 6.4.
Specimens for monitoring of VHF patients should be preserved at least until the patient is discharged or a diagnosis is established in a deceased patient, and should then be disposed of in a safe manner (autoclaved or sent for incineration). However, specimens should be offered to the Special Pathogens Unit (SPU) at the National Institute for Communicable Diseases (NICD) rather than destroyed, since much valuable information is gained from the examination of serial samples from VHF patients.
Ideally a separate clotted blood sample should be taken daily from confirmed VHF patients for submission to NICD, but these can be submitted together when the patient is discharged.
6.3 Isolation precautions (formerly known as barrier-nursing procedures)
Although the VHFs are seldom encountered, the consequences of being unprepared can be extremely serious. All medical institutions should formulate and implement contingency plans for isolating and managing VHF patients, even on a temporary basis. The aims should be to:
● Identify facilities and resources which can be utilized for isolating and managing VHF patients.
● Provide health care workers with training and instructions specific to their duties so that they are able to act in an informed manner when suspected cases of VHF are encountered.
● Train all staff members to recognize potential cases of VHF, but ensure that critical assessment of such cases is performed by experienced clinicians and infection control personnel.
● Train suitable volunteers in isolation precautions. Experience has shown that when VHF occurs in an institution where there has been no prior discussion of VHFs and training in isolation precautions it may be extremely difficult to obtain volunteers. Do not be caught unprepared.
● Ensure that infection control personnel monitor safety practices during isolation precautions and place staff who are in contact with VHF patients or fomites under observation (see section 7.3).
● Establish proper channels of communication so that relevant members of staff at all levels are informed promptly of the existence of a suspected case of VHF, or of the impending arrival at a hospital of such a patient, and of all key developments in the handling of the case.
● Extend the system of communication to outside officials who need to be kept informed, such as Communicable Disease Control officials of the national and provincial Departments of Health (see section 7).
● Make provision for well-informed responses to enquiries from news media (see section 7).
The minimum accommodation required for isolation precautions consists of one room in which the patient may be isolated and an ante-room or adjacent room where staff can don and remove personal protective equipment (PPE). Ideally, isolation units should have separate entrance and exit (‘clean and dirty’) channels, and it is advantageous if the ante- room has a hand-basin and if ablution facilities are located in convenient proximity to the patient's room. The equipments and supplies required in the patient isolation room are listed in Table 6.3 below. Since VHF patients are often in need of intensive care, the isolation unit may need to consist of a cubicle or section of an ICU ward which can be closed off.
In addition to the patient room and ante-room there should be:
● An area suitable for a nursing station where staff wait when not in direct attendance on the patient.
● An area or room for storing supplies and equipment.
● A room or enclosed area for changing from street clothes into surgical theatre or equivalent clothing.
● An observation room/ward in which to place high risk contacts of VHF patients who become sick, i.e. potential but unconfirmed secondary cases (such a facility is seldom
● A two-way communications system between the patient isolation room and the nursing station if necessary.
● Purpose-built isolation facilities should theoretically have negative pressure air- conditioning systems with high-efficiency particulate air (Hepa) filters on the exhaust ducts, but there are very few such units in the world and these are at major research facilities. It was speculated that 2 nurses who did not have direct contact with patients, but handled fomites such as bedpans, acquired Congo fever infection as a result of virus assing through an air-conditioning system during a nosocomial outbreak in South Africa in 1984, but there was no proof that this had occurred, and there is no evidence that air-conditioning systems constituted a hazard in the isolation of a further 200 VHF patients in South Africa, or in large outbreaks managed by international response teams elsewhere in Africa. Hospitals encounter suspected VHF patients so infrequently that it is not feasible to build dedicated patient isolation units and keep them vacant on standby. Instead, it is necessary to identify suitable facilities which remain in normal use and can be utilized for isolation of patients as the need arises.
Much of the PPE is available in disposable plastic or paper form at all hospitals and clinics. Up to 25 changes of protective clothing may be required per day in nursing a patient during the critical phase of VHF illness (not all patients become severely ill or exhibit bleeding tendencies). Some hospitals utilize mended and condemned linen and theatre clothes for nursing VHF patients, but dye the items an obvious colour to help ensure that they are disposed of safely. Ideally, hospitals should keep stocks of the essential items in readiness, but this involves dedication of funds and secure storage space, plus rotation of perishable items. Alternatively, stocks should be secured immediately an emergency arises. Formidable epidemic disease packs (FED packs) containing virtually all of the above PPE items are available commercially, and customized packs can be prepared to order or within the hospital.
It is notable that international teams operating under the auspices of the World Health Organization to control outbreaks of Marburg and Ebola haemorrhagic fevers in Africa use only standard PPE items specified above. Almost all VHF patients in South Africa have been nursed without special safety equipment, and all nosocomial infections occurred before the patients were placed under conditions of isolation precautions.
In the past, some hospitals in South Africa acquired special safety equipment for protection of staff against nosocomial infection, ranging from containment bed isolators, full-face respirators (gas masks) to battery-operated positive-pressure ventilated respirators (‘pappers’). There are disadvantages associated with each of these items: bed isolators are very expensive and occupy a large floor space; gas masks are tiring to use and tend to become fogged, thus reducing visibility and efficiency; pappers require expensive semi- disposable hoods and interfere with the use of stethoscopes.
Nevertheless, the use of pappers may be warranted for particularly hazardous procedures, such as intubation of VHF patients under intensive care. Hoods may be re-used by the same staff member for successive entries into the patient isolation room provided they are disinfected on exit from the isolation room as described below (they should be marked with the name of the user). Power supply points will be required in the ante-room for re-charging batteries, plus a rack or coat hooks for hanging respirators and hoods when not in use.
Ideally, specifically trained, volunteer staff should be used for nursing VHF patients, and personnel who were in contact with the VHF patient/s before isolation precautions were implemented should be utilized first to limit potential exposure of further members of staff. Select persons of calm disposition able to cope with the stress of nursing VHF patients under strict isolation precautions.
Nosocomial infections can almost invariably be traced to fundamental lapses in technique, such as needle-sticks, against which most safety equipment cannot protect. Fatigue causes mistakes and hence adequate numbers of staff should be delegated to nursing patients under conditions of strict isolation precautions without seriously depleting the rest of the hospital or unnecessarily exposing too many individuals to VHF. If the nursing load is too heavy, as when multiple patients are involved, it may be necessary to suspend some or all- routine functions of the hospital. Counselling of staff (plus patients and families) should be offered to alleviate stress.
Shifts should be limited to a maximum of 8 hours (6 hours are preferable) to ensure a high degree of efficiency. Intensive nursing of critically ill VHF patients may require 3-5 persons per shift, 1-2 of whom are in the patient's room on a 1-2 hourly rotation. Low profile nursing of moderately ill patients requires less staff and often it is unnecessary to maintain a constant presence in the patient's room.
In addition to the staff members who are directly in attendance on the patient, one member of the nursing or administrative staff should remain outside of the isolation area to control communications, logistics and access to the isolation suite. In large hospitals it may be necessary to use security officers to control access to the isolation suite.
Domestic and any other staff who have not been specifically instructed in isolation precautions must be excluded from the isolation suite.
All medical and auxiliary staff (ambulance and laboratory personnel) who come into contact with a suspected or confirmed VHF patient or fomites, either before or after the institution of isolation precautions, must be placed under observation (see section 7). This should be done formally but the precautionary nature of the measure should be explained carefully.
Incidents constituting possible exposure to infection, e.g. needle sticks or other direct contact of skin with patient’s blood or body fluids, must be recorded and promptly brought to the attention of the hospital's infection control team to decide on any action to be taken (see section 7).
Baseline blood counts plus serum transaminase tests may be performed for persons who have had contact with a VHF patient or fomites, and serum samples should be kept frozen for later use if suspected infection occurs. However, this should be limited to persons with definite exposure to infection such as a needle-stick with known infected blood. Indiscriminate bleeding of contacts generates undue concern and unreasonable demands from people who have not had genuine exposure to infection.
Placing a patient into isolation
Explain to the patient and family that isolation precautions are being instituted and make an effort to reassure them. The donning of protective clothing by medical personnel can have a demoralizing effect on lay people.
Establish from the clinician in charge whether or not the patient's immediate family will be permitted to visit the patient (under supervision and with proper protective clothing). Inform the family accordingly and arrange for instruction in correct use of protective clothing.
Ensure that all staff are informed that the patient is being placed into isolation, institute control over access to the isolation suite and display appropriate warning notices. Henceforth only specifically authorized personnel may have access to the patient and all staff must wear protective clothing when tending the patient.
The patient is transferred to the isolation room on his/her bed, and all other items of equipment required from the original ward (e.g. locker, ventilator, monitor, etc.) are moved with the patient. The procedure for receiving VHF patients from outside the hospital is described in section 7.
All non-essential items, including the patient's records, are left in the original ward and are decontaminated in the prescribed manner by personnel wearing protective clothing (see section 6.4). New patient records are started and kept outside of the isolation room.
All other patients who were in the original ward with the VHF patient are transferred, preferably to a single other ward, so that the original ward can be decontaminated (see section 6.4). Sometimes it is more convenient to leave the VHF patient in the original ward and convert it into an isolation room.
Ensure that the infection control team prepares a register of all persons deemed to have had contact with the VHF patient/s and places contacts under observation (see section 7.3).
Ensure that a duty register is kept of all staff shifts and visits to the patient, to ensure traceability of contact with the patient.
Dressing for entering the patient isolation room
In a change-room or other suitable area close to the entrance to the isolation suite, staff remove all jewellery and replace their street clothes with surgical theatre tops and trousers, or equivalent cover-all garments (washable fabric or disposable), plus canvas or similar slip- on shoes. These clothes are worn for the duration of the work shift and are used to move around in the vicinity of the isolation suite, but an extra layer of protective clothing is donned in the ante-room for entry into the patient isolation room:
● Long-sleeved, waterproof, disposable gown.
● Vinyl or rubber apron if more than light duties are involved, e.g. bleeding patients.
● Two pairs of latex surgical gloves, one worn over the other - the cuffs of the outer pair of gloves should be pulled over the cuffs of the gown and taped in place with masking tape around the wrist.
● Disposable balaclava-type cap.
● Disposable face-mask, e.g. N95 – cannot be used with facial hair (beards).
● Goggles or acrylic visor, or disposable visor.
● A disposable combination visor-face mask can replace a separate mask and goggles or visor.
● Alternatively, a positive-pressure ventilated respirator (papper) with hood could replace the balaclava, face-mask and goggles or visor.
● Two pairs of overshoes, one over the other, or heavy duty plastic bags taped to the trouser legs, or waterproof boots.
Needles, other sharp objects, patient's blood, blood-contaminated discharges and equipment soiled with blood constitute the greatest danger and must be handled with extreme care. Gloved hands contaminated with patient's blood or discharges should be dipped into 500 ppm chlorine disinfectant solution (see section 6.4) kept in the isolation room. Gloves must be checked frequently for tears or punctures and if the patient bleeds profusely, both inner and outer gloves must be changed hourly and the hands washed thoroughly in soap and water or surgical scrub disinfectant.
Procedure for leaving the patient isolation room
The procedure for leaving the isolation room must be followed strictly to prevent contamination of personnel and the environment. Double refuse or autoclave bags (heavy duty), which are used to receive discarded protective apparel, are placed one inside the other in a bin or holder in the ante-room with 20-30 cm of the top of the bags folded back over the rim of the bin or holder to form a clean margin when the bag is sealed. The bin is placed close to the door leading from the patient isolation room.
On leaving the patient isolation room, the outer overshoes are removed and placed in the disposal bag. Waterproof overshoes or boots may be dipped into a bucket/tray of 500 ppm chlorine disinfectant (see section 6.4) before being removed. The outer gloves are dipped or washed in 500 ppm chlorine disinfectant (see section 6.4), peeled off and discarded into the disposal bag. The inner gloves are used to remove the other items of protective wear and to place them in the disposal bag as follows:
● Goggles or acrylic visors are removed and placed in 500 ppm chlorine disinfectant (see section 6.4).
● Disposable combination visor-masks are discarded into the disposal bag.
● If a positive-pressure respirator is being worn, an assistant in the ante-room swabs or sprays the outer surface of the hood with 500 ppm chlorine disinfectant (see section 6.4) and with gloved hands helps to remove the respirator; the swabbed hood is hung on a hook or rack to dry; the respirator itself is hung or placed on a suitable surface and connected to a battery charger. Respirator hoods are marked with the names of individual members of the team for re-use, and are discarded for incineration or safe disposal when no longer required.
Facemasks and balaclava caps are removed and placed in the disposal bag.
● Next, aprons and gowns are removed and folded or rolled in the process so that outside surfaces are on the inside and they are placed in the disposal bag.
● The inner pair of overshoes and finally the inner gloves are removed and placed in the disposal bag, and the hands are washed thoroughly with soap and water or surgical scrub disinfectant (use of ethyl or isopropyl alcohol is not recommended for disinfection of the hands in nursing VHF patients).
● The inner and outer top rims of the disposal bags are sprayed with 500 ppm chlorine disinfectant (section 6.4) and sealed by a gloved assistant, conveniently with plastic cable-ties obtainable from electrical or hardware stores, or with adhesive tape. The double bags are sealed into a third bag, or several layers of bags if necessary to prevent leakage. It is useful if the outer bag is colour-coded, e.g. red, to indicate that it contains biohazardous material due for incineration. However, red bags are commonly used for waste in hospitals.
● The outer bag is labeled with biohazard stickers and sent for incineration under supervision, or sealed into the container of a commercial biohazardous materials disposal contractor, e.g. Sanumed®.
● Surgical theatre clothes or equivalent cover-all garments and footwear are removed in the outer change room and discarded into laundry or disposal containers as appropriate, and staff don their street clothes. Preferably, staff should be able to take a shower bath before leaving the isolation area.
Procedures for dealing with potentially hazardous incidents
All incidents constituting possible exposure to infection, such as needle stick injuries and splashing with patient’s body fluids must be recorded and reported to infection control staff to decide on appropriate action, and an Employer’s Report of an Accident Form (Compensation for Occupational Injuries and Diseases Act, 1993) must be completed and submitted.
First aid procedures should be applied as considered necessary, eg bleeding of needle stick or sharp instrument injury sites should be encouraged and wounds bathed in copious 500 ppm chlorine disinfectant (see 6.4).
Infection control staff in consultation with senior clinicians and management should decide whether staff members potentially exposed to infection should be placed in quarantine (section 7), subjected to prophylactic treatment (section 6.1), or simply kept under observation (section 7).
Patient care facilities should be subjected to routine disinfection, but overt spillages of hazardous materials should be dealt with as they arise (section 6.4).
Discharge of patients
Provided they are well, Congo fever, Rift Valley fever and other arbovirus disease patients can be removed from strict isolation precautions, or even discharged from hospital, two weeks after onset of illness, but they should remain under supervision and refrain from strenuous activity for a month or more, depending on their progress. Meningism, encephalitis and ocular lesions can occur as late complications of Rift Valley fever.
Patients with a diagnosis of any of the other African haemorrhagic fevers should be nursed in isolation for at least 3 weeks after onset of illness. Sexual transmission of Marburg virus in semen has been recorded two months after recovery of the patient and the same could probably occur with Ebola virus. Excretion of Lassa fever virus in urine has been observed to occur over a period of a few weeks, and hence the discharge of Lassa fever or Lujo virus patients from hospital should be made consequent upon failure to isolate virus or to detect viral nucleic acid by RT-PCR in three consecutive urine samples collected on separate days. The same would apply to haemorrhagic fever with renal syndrome (HFRS) patients, but culture of the viruses is difficult and erratic.
Recovery from VHF may be marked by prolonged convalescence and it is advisable that patients should be kept under casual surveillance for about 3 months. They should be warned of the possibilities of their transmitting infection through intimate contact during this time.
If convenient, serum samples from recovered patients should be sent for monitoring of antibody levels at intervals after recovery as opportunity arises; useful diagnostic information on the duration of IgM and IgG responses is accumulated in this manner. Patients should be approached about the possibility of donating immune plasma once they are fully recovered, for preparation of control reagents for diagnostic tests, or for possible therapeutic use. Offers to donate plasma can be discussed with the Special Pathogens Unit at NICD (telephone numbers 011 386 6339, 082 903 9131, 082 908 8042 and 082 908 8045).
6.4 Disinfectants and decontamination
The use of disinfectants is not a substitute for sterilization by physical means, especially heat as in autoclaving or incineration. However, there are many situations where it is necessary to resort to the use of disinfectants, and the present discussion is limited to requirements for managing VHF patients. The use of brand names does not imply recommendation of a product to the exclusion of similar preparations. It should be remembered that mechanical cleansing is an integral part of proper disinfection: excess organic matter rapidly reduces the efficacy of disinfectants.
Choice of general disinfectant
Inorganic chlorine, in the form of diluted household bleach, has been used as the disinfectant of choice in controlling outbreaks of VHF in Africa because it is effective, relatively inexpensive and readily available. However, inorganic chlorine corrodes metals and tends to degrade fabrics. Brand-name household bleaches contain 5% sodium hypochlorite and are diluted as follows for use:
A 10% aqueous solution of household bleach (one part bleach plus 9 parts water) yields 0.5% hypochlorite, or approximately 5000 ppm chlorine, and is used for disinfecting overt spillages of contaminated materials, excreta (organic wastes) and surfaces of corpses.
A 1:100 aqueous solution of household bleach (one part bleach plus 99 parts water, or
1 part of 10% diluted bleach plus 9 parts of water) yields 0.05% hypochlorite, or approximately 500 ppm chlorine, and is used for disinfecting gloved hands, walls and floors without overt spillages of contaminated materials, clothing, bedding, equipment and instruments, and the outer surfaces of sealed plastic bags containing infected or contaminated materials.
One or two crystals of potassium permanganate (Condy’s crystrals) can be added to undiluted household bleach to impart a pink colour to the diluted solutions of disinfectant for easy identification. Fresh stocks of diluted disinfectant should be prepared daily.
‘Organic’ chlorine formulations which contain a detergent, an anti-corrosive agent and chlorine incorporated in or complexed to organic molecules (chloro-cyanurates and chloramines) offer clear advantages over inorganic hypochlorite. A dry granular preparation of this type is sold in South Africa as Biocide D (6g granules per sachet), or as Biocide D Extra (30g granules per sachet) (Johnson Diversey, Germiston):
Twenty sachets of Biocide D Extra (600g) dissolved in 10 litres of water yields 0.5% hypochlorite, or approximately 5000 ppm chlorine, and is used for disinfecting overt spillages of contaminated materials, excreta (organic wastes) and surfaces of corpses.
Two sachets of Biocide D Extra (60g) dissolved in 10 litres of water yields 0.05% hypochlorite, or approximately 500 ppm chlorine, and is used for disinfecting gloved hands, walls and floors without overt spillages of contaminated materials, clothing, bedding, equipment and instruments, and the outer surfaces of sealed plastic bags containing infected or contaminated materials.
Fresh solutions should be prepared daily.
Disinfectant solutions should be clearly labelled with the concentration of active ingredient and date of preparation.
Choice of hand disinfectant
Gloved hands are generally rinsed in 500 ppm chlorine, and although this can also be used to rinse bare hands, it is recommended that when surgical gloves are removed after nursing or transportation of VHF patients, or performance of clinical pathology tests, the hands should be thoroughly washed with soap and water, or with a surgical scrub preparation. Ethyl or isopropyl alcohol preparations are not recommended for disinfection of the hands in managing VHF patients, although they can be used as skin disinfectants for injection of patients.
Decontamination and disposal of hazardous items
A specific individual in each nursing shift, or ambulance crew transporting a VHF patient, should be responsible for supervising decontamination and disposal of biohazardous items. All items leaving the isolation unit (patient's room and anteroom, or ambulance) should be enclosed in double layer autoclave bags (or more layers if necessary to prevent leakage) and sealed with cable ties or adhesive tape. The outer surface should be labelled with biohazard stickers and swabbed with 500 ppm chlorine disinfectant.
Disposable items should be sent for incineration under supervision and re-useable items for autoclaving. Crockery and cutlery used for feeding VHF patients should ideally be of the disposable type and incinerated along with food wastes.
Bedpans and other containers with patient secretions, excretions and other wastes such as vomitus and blood, should be flooded with copious 5000 ppm chlorine disinfectant, left for at least 30 minutes, and sealed into adequate layers of leak-proof autoclave bags or other secure secondary containers (e.g. stainless steel container). The outer surfaces of the bags or containers should be swabbed with 500 ppm chlorine disinfectant, labelled with biohazard stickers and the items removed for autoclaving and cleaning. Autoclaved wastes can be flushed into municipal sewers. After flushing, bedpans are cleaned with 500 ppm chlorine disinfectant. Thoroughly disinfected wastes (prolonged exposure to copious disinfectant) can also be discarded into sealed disposal pits, or buried.
It is convenient to use chemical toilets instead of bed pans for ambulant patients.
Vinyl, rubber and other items which are degraded by autoclaving could be discarded and incinerated, or subjected to prolonged immersion in 500 ppm chlorine disinfectant.
The hoods of battery-operated positive-pressure ventilated respirators (‘pappers’) are discarded for incineration at the termination of patient treatment, and the respirators are swabbed with 500 ppm chlorine disinfectant, and sealed into labelled bags and sent for gaseous sterilization.
Hypodermic and intravenous needles should be used with great care, discarded into rigid- walled disposal containers, flooded with a 5000 ppm chlorine disinfectant (see 6.4), sealed into leak-proof bags, labelled and sent for incineration.
Used linen and cloth items of protective wear should be sealed into labelled bags and autoclaved before laundering, but consideration should be given to incinerating grossly contaminated items such as bloodstained mattresses and pillows. Items, which are not visibly soiled, could be soaked in 500 ppm chlorine disinfectant for 30 minutes before laundering. Persons laundering cloth protective apparel or bedding used for VHF patients should don personal protective equipment (PPE) as described for isolation precautions (see section 6.3).
Vomitus, blood and other overt spillages on floors and similar impervious surfaces should be flooded with 5000 ppm chlorine disinfectant, covered with paper towels and left for 30 minutes before removal.
Floors of VHF patient isolation units should be mopped and drains flushed with 500 ppm chlorine disinfectant daily, or whenever there is spillage of potentially contaminated material. Rinsed mops should be soaked in 500 ppm chlorine disinfectant for 30 minutes. At the termination of patient treatment the walls and all impervious surfaces in isolation units (lockers and tables) should be swabbed in addition to the disinfection of floors and drains. The same procedures should be applied to mortuaries and laboratories handling corpses or samples of suspected or confirmed VHF patients.
Patient records, which have been kept in an infected environment, can be bagged and autoclaved, or the information preserved by other means, e.g. copied from records, taped to a window or glass partition, or transmitted via telephone.
6.5 Disposal of corpses
Corpses of suspected VHF patients may be processed for immediate disposal if an etiological diagnosis has been confirmed. If a diagnosis has not been established, then in terms of the Health Act 61 of 2003 certain medical practitioners are empowered to authorize the performance of an autopsy to determine the cause of death, as described in section 7 of this document. Usually the autopsy procedures are limited to collecting blood by cardiac puncture and taking liver samples with biopsy needles.
After the autopsy specimens have been taken, the corpse may be held under refrigeration in a mortuary if the facilities exist, while laboratory investigations to eliminate VHF proceed. This usually takes a week, and if a diagnosis of VHF is eliminated, it may be deemed safe and/or necessary to proceed with a full autopsy to establish the cause of death.
For disposal, corpses are washed with 5000 ppm chlorine disinfectant (see section 6.3 above). Orifices are plugged with gauze and puncture sites are taped or sealed (Opsite®, S & N Pharmaceuticals Pty Ltd). The corpse is enclosed in an impervious body bag and sealed (it is advantageous if the body bag has an air-valve). The attendants change protective clothing, swab the body bag with fresh disinfectant and seal the corpse into a second impervious body bag. After disinfection of the outer body bag, the corpse can be removed for storage in a mortuary or placed in a coffin for disposal. If impervious body bags are not available, adequate layers of stout plastic shrouds may be used.
The shrouded corpse should be placed in a coffin packed with absorbent material (sawdust) which is moistened with 5000 ppm chlorine disinfectant (see 6.4). The coffin should be sealed and wiped with 500 ppm chlorine disinfectant (see 6.4). The corpse should be cremated or buried under the supervision of a representative of the provincial Department of Health and Hospital Services, more specifically the office of the Coordinator of Communicable Disease Control.