Questions

South African VHF Guidelines — Questions

Study questions for South African VHF Guidelines.

Mock Exam mode

Sit this set one question at a time. Multiple-choice questions mark themselves; written questions reveal a tickable mark scheme so you can score your own answer. You get a combined score at the end.

20 questions: 11 MCQ, 9 written.

High-priority (past-paper) questions only

a. Recognise and pause. Treat the request as a possible viral haemorrhagic fever (VHF); do not process the sample routinely, and check it against the current suspected-case definition (fever or a compatible symptom, travel to the outbreak area within 21 days and contact with a case, with malaria excluded).

b. Consult and notify. Telephone the National Institute for Communicable Diseases (NICD) hotline for a risk assessment before handling the sample further, alert the receiving reference laboratory, and notify the case as a Category 1 Notifiable Medical Condition and to the provincial coordinator.

c. Handle and package safely. Contain the sample under enhanced precautions; if VHF testing is agreed, submit one clotted and one EDTA tube with the case investigation form, in Category A packaging to UN2814, kept cold, by arranged courier to the reference laboratory.

d. Essential tests and isolation. Ensure the patient is isolated with barrier precautions, run only the clinically essential tests on site under precautions, and exclude malaria in parallel.

Prior consultation: the sample is sent only after discussion, through the hotline, with an NICD medical officer and the receiving laboratory.
Specimen and form: one clotted-blood tube and one EDTA tube, with the completed case investigation form.
Packaging: Category A triple packaging to UN2814 under International Air Transport Association (IATA) packing instruction 620, with biohazard marking.
Temperature: kept cold with cold packs; whole blood is not frozen.
Courier: moved by a dedicated arranged courier, not routine transport.

Triple packaging protects handlers and the environment through three layers:

Primary receptacle: the sealed, leak-proof specimen tube, wrapped in enough absorbent material to soak up the entire contents if it breaks.
Secondary packaging: a durable, leak-proof, sealed container enclosing the primary receptacle.
Outer packaging: a rigid shipping container of adequate strength, bearing the biohazard and Category A labelling.

For a suspected VHF specimen the system is classified Category A, UN2814, under International Air Transport Association (IATA) packing instruction 620, kept cold and moved only by prior arrangement.

A complete answer explains that essential tests are still done, but under precautions, and that Ebola confirmation is handled separately.

Do the essential tests. Life-saving and monitoring tests (full blood count, malaria smear, coagulation, urea and electrolytes, liver function, cross-match) are performed on site and never withheld while viral haemorrhagic fever (VHF) is being considered.

Under enhanced precautions. A small team of experienced staff works in a demarcated area; any aerosol-generating or open step is done inside a biosafety cabinet under enhanced protective equipment; closed automated systems are used where possible; and waste is handled as high-risk.

Inactivation and closed systems. Where possible, samples are chemically inactivated before analysis, and closed analysers reduce exposure.

Ebola confirmation is separate. The Ebola test itself is not done in the routine laboratory: a specimen is sent, after prior consultation and under Category A packaging, to the reference laboratory. The routine samples are traced and treated as potentially infectious, and destroyed only after consulting the reference laboratory.

A contact of a filovirus, Lassa or Lujo case has temperature recorded twice daily for 21 days from the last contact.

The window is 14 days for Crimean-Congo haemorrhagic fever, and Rift Valley fever needs no such observation; the other intervals are wrong.

A suspected VHF specimen is a Category A infectious substance, shipped under UN2814 with International Air Transport Association (IATA) packing instruction 620.

Routine diagnostic samples are the lower Category B (UN3373); the exempt, non-hazardous and Category C options do not apply.

An early negative must be backed by a convalescent antibody sample, because virus can still grow in culture days after antigen, genome and antibody are negative.

Discharge, no further testing, a malaria smear or antibiotics do not address an early false negative.

A suspected VHF is notified as a Category 1 Notifiable Medical Condition through the Notifiable Medical Conditions application, alongside the hotline call, without waiting for laboratory confirmation.

It is not reported by a routine return or only after confirmation, and the World Health Organization is notified by the national department, not the clinician.

Malaria is the priority exclusion in every suspected VHF, because it is far more common in the same patients and can coexist with a VHF.

The other conditions are not the critical parallel diagnosis.

The reference laboratory accepts a VHF specimen only after prior consultation, through the hotline, with a National Institute for Communicable Diseases (NICD) medical officer and the receiving laboratory, so nothing is dispatched unannounced.

Death, a malaria result, an observation period or ministerial approval are not the gate.

The standard submission is one clotted-blood tube and one EDTA tube, with the completed case investigation form.

A single tube, urine or a swab alone, or a dried blood spot is not the required submission.

Confirmatory VHF testing is done only at the National Institute for Communicable Diseases (NICD) reference laboratory, the Special Viral Pathogens Laboratory, the only biosafety level 4 facility in Africa.

Routine, hospital, private and provincial laboratories may run supporting tests under precautions but do not perform VHF confirmation.

Spills of blood and body fluids are treated with 0.5% chlorine (5,000 parts per million), left in contact for at least 30 minutes.

The weaker 0.05% solution is for skin and lightly soiled items; the other concentrations are wrong.

Negative-pressure ventilation is not required: South African experience across more than two hundred patients shows that standard isolation without it is adequate.

An ante-room, contact observation, chlorine decontamination and barrier nursing are all part of safe management.

Crimean-Congo haemorrhagic fever is the commonest indigenous VHF in South Africa, with fewer than 10 cases a year, chiefly in the Northern Cape and Free State.

Lassa, Marburg and Ebola are imported rather than indigenous, and Rift Valley fever appears only in epidemic years.

Moderate risk: a VHF-compatible febrile illness with a rural or tropical exposure, or contact with animals, ticks or mosquitoes, or an indirect link to a VHF case, but no direct contact with a case and no bleeding.
High risk: a patient either severely ill with fever and haemorrhage, or with a definite VHF exposure, such as a health worker who falls ill within the incubation window of caring for a confirmed case, or a close contact of a known case.

Immediate first aid: wash a contaminated skin wound with soap and water, encouraging bleeding, and irrigate exposed mucous membranes with water or saline.
Report and risk-assess: notify occupational health and the reference laboratory at once for a risk assessment.
Post-exposure vaccination: for a genuine high-risk Zaire ebolavirus exposure, the rVSV-ZEBOV vaccine is offered as soon as possible, since its benefit depends on early administration.
Monitoring: record temperature twice daily for 21 days from the exposure, isolating and managing as a suspected case if fever or symptoms develop.

A complete answer covers the containment level, what may be done on site, and how specimens are handled and moved.

Containment. Confirmatory testing is done only at the national reference laboratory, the sole biosafety level 4 facility in Africa; live-virus work is confined there.

On-site testing. The managing laboratory may run the essential tests to exclude other diagnoses and monitor the patient, but any aerosol-generating step is done inside a biosafety cabinet, under enhanced personal protective equipment, by a small team of experienced staff, and clinically essential tests are never withheld.

Specimen handling and transport. Specimens are Category A infectious substances, triple-packaged to UN2814 under International Air Transport Association (IATA) packing instruction 620, kept cold and not frozen, and dispatched only after prior consultation with the reference laboratory.

Inactivation. Molecular assays run on chemically inactivated samples allow safe testing at lower containment.

A complete answer covers isolation, protective equipment, decontamination, and the handling of contacts and the deceased.

Isolation. Isolate the patient in a room with an ante-room for donning and doffing protective equipment; negative-pressure ventilation is not required, as standard isolation has proven adequate in South African practice.

Personal protective equipment. A gown or coverall, a plastic apron, an N95 respirator, eye protection, a double pair of gloves and boot covers, put on and removed with a trained partner watching.

Decontamination. Chlorine at 0.5% for spills, body fluids and surfaces, and 0.05% for skin and lightly soiled items, made up fresh daily.

Contacts and the deceased. Contacts are placed under active observation; a body is disinfected, double-bagged and refrigerated pending diagnosis; and staff exposures are logged and monitored.

A complete answer covers the tests, where they are done, the biosafety level and notification.

Tests. Acute infection is confirmed by reverse transcription polymerase chain reaction for viral genome and by antigen detection, with serology (fluorescent antibody test and enzyme-linked immunosorbent assay) for antibody; an early negative is backed by a convalescent sample because culture can still turn positive later.

Where and at what biosafety level. Confirmatory testing is done only at the National Institute for Communicable Diseases (NICD) reference laboratory at biosafety level 4, after prior consultation; the referring laboratory sends one clotted and one EDTA tube with the case investigation form under Category A packaging.

Notification. Marburg is notified as a Category 1 Notifiable Medical Condition through the application, alongside the hotline call.

High priorityClinical scenarioYou receive a sample from a patient who has just returned from eastern Democratic Republic of the Congo with a request to test for Ebola virus. How do you proceed? [6]
Model answer
a. Recognise and pause. Treat the request as a possible viral haemorrhagic fever (VHF); do not process the sample routinely, and check it against the current suspected-case definition (fever or a compatible symptom, travel to the outbreak area within 21 days and contact with a case, with malaria excluded).

b. Consult and notify. Telephone the National Institute for Communicable Diseases (NICD) hotline for a risk assessment before handling the sample further, alert the receiving reference laboratory, and notify the case as a Category 1 Notifiable Medical Condition and to the provincial coordinator.

c. Handle and package safely. Contain the sample under enhanced precautions; if VHF testing is agreed, submit one clotted and one EDTA tube with the case investigation form, in Category A packaging to UN2814, kept cold, by arranged courier to the reference laboratory.

d. Essential tests and isolation. Ensure the patient is isolated with barrier precautions, run only the clinically essential tests on site under precautions, and exclude malaria in parallel.
High prioritySAQDescribe how a suspected viral haemorrhagic fever specimen is transported to the National Institute for Communicable Diseases (NICD) biosafety level 4 laboratory. [5]
Model answer
- Prior consultation: the sample is sent only after discussion, through the hotline, with an NICD medical officer and the receiving laboratory.
- Specimen and form: one clotted-blood tube and one EDTA tube, with the completed case investigation form.
- Packaging: Category A triple packaging to UN2814 under International Air Transport Association (IATA) packing instruction 620, with biohazard marking.
- Temperature: kept cold with cold packs; whole blood is not frozen.
- Courier: moved by a dedicated arranged courier, not routine transport.
High prioritySAQExplain the triple-packaging system for transporting a viral haemorrhagic fever (VHF) specimen. [6]
Model answer
Triple packaging protects handlers and the environment through three layers:
- Primary receptacle: the sealed, leak-proof specimen tube, wrapped in enough absorbent material to soak up the entire contents if it breaks.
- Secondary packaging: a durable, leak-proof, sealed container enclosing the primary receptacle.
- Outer packaging: a rigid shipping container of adequate strength, bearing the biohazard and Category A labelling.
For a suspected VHF specimen the system is classified Category A, UN2814, under International Air Transport Association (IATA) packing instruction 620, kept cold and moved only by prior arrangement.
High priorityExam-styleDiscuss the laboratory management of samples from a patient with possible Ebola sent for routine diagnostic testing, that is, for tests other than Ebola testing. [6]
Model answer
A complete answer explains that essential tests are still done, but under precautions, and that Ebola confirmation is handled separately.

Do the essential tests. Life-saving and monitoring tests (full blood count, malaria smear, coagulation, urea and electrolytes, liver function, cross-match) are performed on site and never withheld while viral haemorrhagic fever (VHF) is being considered.

Under enhanced precautions. A small team of experienced staff works in a demarcated area; any aerosol-generating or open step is done inside a biosafety cabinet under enhanced protective equipment; closed automated systems are used where possible; and waste is handled as high-risk.

Inactivation and closed systems. Where possible, samples are chemically inactivated before analysis, and closed analysers reduce exposure.

Ebola confirmation is separate. The Ebola test itself is not done in the routine laboratory: a specimen is sent, after prior consultation and under Category A packaging, to the reference laboratory. The routine samples are traced and treated as potentially infectious, and destroyed only after consulting the reference laboratory.
MCQ
A contact of a filovirus case is monitored by twice-daily temperature for how long?
- A. 7 days
- B. 10 days
- C. 14 days
- D. 21 days
- E. 28 days
Show answer
Correct answer: D
A contact of a filovirus, Lassa or Lujo case has temperature recorded twice daily for 21 days from the last contact.

The window is 14 days for Crimean-Congo haemorrhagic fever, and Rift Valley fever needs no such observation; the other intervals are wrong.
MCQ
A specimen from a suspected viral haemorrhagic fever (VHF) case is classified for transport as:
- A. Category A, UN2814
- B. Category B, UN3373
- C. An exempt human specimen
- D. Non-hazardous material
- E. Category C
Show answer
Correct answer: A
A suspected VHF specimen is a Category A infectious substance, shipped under UN2814 with International Air Transport Association (IATA) packing instruction 620.

Routine diagnostic samples are the lower Category B (UN3373); the exempt, non-hazardous and Category C options do not apply.
MCQ
An early viral haemorrhagic fever (VHF) specimen negative on antigen, genome and antibody should be followed by:
- A. Immediate discharge of the patient
- B. A repeat malaria smear
- C. A convalescent antibody sample
- D. No further testing
- E. Empirical antibiotics
Show answer
Correct answer: C
An early negative must be backed by a convalescent antibody sample, because virus can still grow in culture days after antigen, genome and antibody are negative.

Discharge, no further testing, a malaria smear or antibiotics do not address an early false negative.
MCQ
How is a suspected viral haemorrhagic fever (VHF) notified in South Africa?
- A. By a routine monthly return
- B. It is not a notifiable condition
- C. As a Category 1 Notifiable Medical Condition
- D. By written notice to the World Health Organization
- E. Only after the reference laboratory confirms the diagnosis
Show answer
Correct answer: C
A suspected VHF is notified as a Category 1 Notifiable Medical Condition through the Notifiable Medical Conditions application, alongside the hotline call, without waiting for laboratory confirmation.

It is not reported by a routine return or only after confirmation, and the World Health Organization is notified by the national department, not the clinician.
MCQ
In any suspected viral haemorrhagic fever (VHF), which diagnosis must be actively excluded in every case?
- A. Malaria
- B. Influenza
- C. COVID-19
- D. Tuberculosis
- E. Hepatitis A
Show answer
Correct answer: A
Malaria is the priority exclusion in every suspected VHF, because it is far more common in the same patients and can coexist with a VHF.

The other conditions are not the critical parallel diagnosis.
MCQ
The reference laboratory accepts a viral haemorrhagic fever (VHF) specimen only after:
- A. The patient has died
- B. Prior consultation via the hotline
- C. A positive malaria test
- D. Forty-eight hours of observation
- E. Written approval from the health minister
Show answer
Correct answer: B
The reference laboratory accepts a VHF specimen only after prior consultation, through the hotline, with a National Institute for Communicable Diseases (NICD) medical officer and the receiving laboratory, so nothing is dispatched unannounced.

Death, a malaria result, an observation period or ministerial approval are not the gate.
MCQ
The standard submission to the reference laboratory for a live suspected viral haemorrhagic fever (VHF) patient is:
- A. A single EDTA tube
- B. A single serum tube
- C. A urine sample and a throat swab in transport medium
- D. One clotted plus one EDTA tube, with the form
- E. A dried blood spot card
Show answer
Correct answer: D
The standard submission is one clotted-blood tube and one EDTA tube, with the completed case investigation form.

A single tube, urine or a swab alone, or a dried blood spot is not the required submission.
MCQ
Where is confirmatory viral haemorrhagic fever (VHF) testing performed in South Africa?
- A. In any accredited diagnostic laboratory
- B. Only at the NICD reference laboratory
- C. At the referring hospital laboratory
- D. At a private pathology laboratory
- E. At a provincial laboratory
Show answer
Correct answer: B
Confirmatory VHF testing is done only at the National Institute for Communicable Diseases (NICD) reference laboratory, the Special Viral Pathogens Laboratory, the only biosafety level 4 facility in Africa.

Routine, hospital, private and provincial laboratories may run supporting tests under precautions but do not perform VHF confirmation.
MCQ
Which chlorine concentration is used for spills of blood and body fluids?
- A. 0.005%
- B. 0.05%
- C. 0.5%
- D. 5%
- E. 50%
Show answer
Correct answer: C
Spills of blood and body fluids are treated with 0.5% chlorine (5,000 parts per million), left in contact for at least 30 minutes.

The weaker 0.05% solution is for skin and lightly soiled items; the other concentrations are wrong.
MCQ
Which is NOT required for safe viral haemorrhagic fever (VHF) isolation in South African practice?
- A. An ante-room for protective equipment
- B. Active observation of contacts
- C. Chlorine decontamination
- D. Barrier nursing
- E. Negative-pressure ventilation
Show answer
Correct answer: E
Negative-pressure ventilation is not required: South African experience across more than two hundred patients shows that standard isolation without it is adequate.

An ante-room, contact observation, chlorine decontamination and barrier nursing are all part of safe management.
MCQ
Which is the commonest indigenous viral haemorrhagic fever (VHF) in South Africa?
- A. Lassa fever
- B. Marburg virus disease
- C. Ebola virus disease
- D. Rift Valley fever in epidemic years
- E. Crimean-Congo haemorrhagic fever
Show answer
Correct answer: E
Crimean-Congo haemorrhagic fever is the commonest indigenous VHF in South Africa, with fewer than 10 cases a year, chiefly in the Northern Cape and Free State.

Lassa, Marburg and Ebola are imported rather than indigenous, and Rift Valley fever appears only in epidemic years.
SAQDifferentiate the criteria for classifying a suspected viral haemorrhagic fever (VHF) patient as moderate risk versus high risk. [4]
Model answer
- Moderate risk: a VHF-compatible febrile illness with a rural or tropical exposure, or contact with animals, ticks or mosquitoes, or an indirect link to a VHF case, but no direct contact with a case and no bleeding.
- High risk: a patient either severely ill with fever and haemorrhage, or with a definite VHF exposure, such as a health worker who falls ill within the incubation window of caring for a confirmed case, or a close contact of a known case.
SAQOutline the immediate management of a high-risk occupational exposure to Ebola virus, including the critical timeframe for intervention. [5]
Model answer
- Immediate first aid: wash a contaminated skin wound with soap and water, encouraging bleeding, and irrigate exposed mucous membranes with water or saline.
- Report and risk-assess: notify occupational health and the reference laboratory at once for a risk assessment.
- Post-exposure vaccination: for a genuine high-risk Zaire ebolavirus exposure, the rVSV-ZEBOV vaccine is offered as soon as possible, since its benefit depends on early administration.
- Monitoring: record temperature twice daily for 21 days from the exposure, isolating and managing as a suspected case if fever or symptoms develop.
Exam-styleDescribe the laboratory biosafety considerations in a suspected viral haemorrhagic fever case. [8]
Model answer
A complete answer covers the containment level, what may be done on site, and how specimens are handled and moved.

Containment. Confirmatory testing is done only at the national reference laboratory, the sole biosafety level 4 facility in Africa; live-virus work is confined there.

On-site testing. The managing laboratory may run the essential tests to exclude other diagnoses and monitor the patient, but any aerosol-generating step is done inside a biosafety cabinet, under enhanced personal protective equipment, by a small team of experienced staff, and clinically essential tests are never withheld.

Specimen handling and transport. Specimens are Category A infectious substances, triple-packaged to UN2814 under International Air Transport Association (IATA) packing instruction 620, kept cold and not frozen, and dispatched only after prior consultation with the reference laboratory.

Inactivation. Molecular assays run on chemically inactivated samples allow safe testing at lower containment.
Exam-styleExplain the infection prevention and control measures required when managing a suspected viral haemorrhagic fever case. [8]
Model answer
A complete answer covers isolation, protective equipment, decontamination, and the handling of contacts and the deceased.

Isolation. Isolate the patient in a room with an ante-room for donning and doffing protective equipment; negative-pressure ventilation is not required, as standard isolation has proven adequate in South African practice.

Personal protective equipment. A gown or coverall, a plastic apron, an N95 respirator, eye protection, a double pair of gloves and boot covers, put on and removed with a trained partner watching.

Decontamination. Chlorine at 0.5% for spills, body fluids and surfaces, and 0.05% for skin and lightly soiled items, made up fresh daily.

Contacts and the deceased. Contacts are placed under active observation; a body is disinfected, double-bagged and refrigerated pending diagnosis; and staff exposures are logged and monitored.
Exam-styleOutline the laboratory diagnostic approach to a suspected acute Marburg virus infection in South Africa, specifying the biosafety level and the notification category. [8]
Model answer
A complete answer covers the tests, where they are done, the biosafety level and notification.

Tests. Acute infection is confirmed by reverse transcription polymerase chain reaction for viral genome and by antigen detection, with serology (fluorescent antibody test and enzyme-linked immunosorbent assay) for antibody; an early negative is backed by a convalescent sample because culture can still turn positive later.

Where and at what biosafety level. Confirmatory testing is done only at the National Institute for Communicable Diseases (NICD) reference laboratory at biosafety level 4, after prior consultation; the referring laboratory sends one clotted and one EDTA tube with the case investigation form under Category A packaging.

Notification. Marburg is notified as a Category 1 Notifiable Medical Condition through the application, alongside the hotline call.