Co-ordination of the public health response
Isolation of cases and effective identification, tracing, vaccination and monitoring of contacts is essential to prevent the spread of infection. Any delay in intervention is likely to make a large impact on the size of the outbreak. Procedures for management of cases and contacts are summarised in
Figure 8.
In order that these activities are properly organised,
Scottish and Regional Smallpox Outbreak Co-ordination Centres (SSOCC and RSOCCs) will be established following the first confirmed case of smallpox. RSOCCs will be required in each of the three Regions in Scotland since cases in one Region may have contacts anywhere in Scotland or the rest of the UK. At a UK level there will be a UK National Smallpox Outbreak Co-ordination Centre (UK-NSOCC) which will alert international authorities, co-ordinate the overall UK response and monitor the UK epidemiological picture (see paragraph 91).
The UK NSOCC will be located in the emergency room of CDSC until April 1 2003, and from then on in the emergency room of the HPA. It will be accountable to the DH. The UK NSOCC will include representatives from PHLS, CAMR, DH, the HPA when established and ID physicians and other clinical advisors.
In Scotland, the Scottish Smallpox Outbreak Co-ordination Centre will be located in St Andrew's House and will include representatives from SEHD, SCIEH, ID physicians and other advisors in nursing, pharmacy and virology, Justice Department and Press Office.
The role of SSOCC is the collation and analysis of epidemiological and laboratory information in Scotland to assist identification of contacts and the source of infection, the overall co-ordination of the public health response in Scotland, briefing Ministers, and liaison with the UK-NSOCC.
RSOCCs will evolve from RSDRGs and will be headed by the lead DPHs supported by a SCIEH epidemiologist.
RSOCCs will fall within the Joint Health Advisory Cell defined in "Deliberate Release of Biological and Chemical Agents in Scotland" (SEHD May 2002). RSOCCs in Scotland will be accountable to SSOCC.
RSOCCs in Scotland will include members of the RSDRGs and in addition representatives from the agencies and groups listed below.
No antiviral drug is currently known to be effective against smallpox virus. It must therefore be assumed that patients suffering from smallpox will require support through the natural course of infection. Cidofovir has been used to successfully treat the orthopox infections
molluscum contagiosum and
orf in humans. The effectiveness of the drug against established smallpox disease is unknown. Depending on supplies, it may be available as a therapeutic option in some cases.
In the presence of multiple organ failure, there is unfortunately no additional benefit from treatment in ICU, and transfer to ICU should be avoided in order to contain the infection.
Those who are unimmunised will suffer disease of varying severity, of which about 40% will be severe or 'fulminant', with an overall case-fatality rate of 25-40%.
Vaccinated individuals who become ill despite vaccination suffer mild or moderate disease in 95% of cases, with a case-fatality rate of less than 1%.
Those with severe disease will require pain relief, hydration, nutrition and airways support during the early part of the illness, maintenance of personal hygiene and skin care during the rash phase, and treatment for secondary bacterial infections if necessary. Patients with milder disease may remain self-caring in many respects, but should be isolated while infectious, to reduce the risk of generating further cases.
The early rash is accompanied by red and blistering lesions in the throat and upper airway. In severe cases, these can be extremely painful, leading to excessive salivation, throat swelling and difficulty in swallowing. Opiate analgesics may be required. If throat swelling threatens the airway, boluses of hydrocortisone may be given to relieve oedema, as for croup or bronchiolitis. The dose for an adult is 200mg intravenously, for a child, 5 mg/kg is often adequate. Although corticosteroids may reduce fever, they have little effect on the evolution of the illness, and do not worsen the outcome of established viral diseases.
Oral hydration, and nutrition with soft food, is preferable as long as it can be adequately maintained. Intravenous hydration is possible in many cases, but a severe skin rash makes the care and maintenance of a peripheral intravenous cannula difficult. It may then be necessary to install a central venous cannula, which will require appropriately trained and vaccinated staff and radiological confirmation of correct positioning of the line.
An extensive rash will result in widespread exudation and crusting, including the scalp area. It may be beneficial to cut the hair short before this happens, to facilitate the shedding of crust and scabs, and to facilitate the maintenance of skin hygiene. Skin swelling can be a major problem, due to the extensive, deep-seated lesions. It is strongly advisable to remove rings and other body jewellery at the onset of the rash, to avoid constriction and ischaemia of digits or of other body areas. The more severe and extensive rashes are painful, and analgesia should be provided.
Skin hygiene contributes importantly to the avoidance of secondary infection, but infection of broken vesicles and pustules, and of denuded skin areas with
Staphylococcus aureus or
Streptococcus pyogenes cannot be avoided in all cases.
Treatment with oral or parenteral flucloxacillin or co-amoxyclav is appropriate (oral clindamycin is an alternative, with a higher risk of diarrhoeal adverse effects; co-trimoxazole is a second choice, with a risk of skin, bone-marrow or liver toxicity, particularly in older adults).
Hospital-acquired resistant organisms such as MRSA may require treatment based on the result of culture and sensitivity data. Further antibiotics may be appropriate according to the patient's clinical condition: cefuroxime axetil or cephradine orally for mild skin infections, injected cefuroxime for more severe infections of skin, chest and urinary tract (alternative to co-amoxyclav). Daily IM or IV teicoplanin is often very effective in both sensitive and resistant Gram-positive infections (including MRSA) and not too labour-intensive to administer.
Secondary bacterial infection of the respiratory tract is much less common, but may be caused by staphylococci or streptococci or rarely
Haemophilus influenzae. Co-amoxyclav, cefuroxime or levofloxacin (or co-trimoxazole as second choice as above) are appropriate oral antibiotics in this situation.
There is often mild conjunctivitis, which requires no specific treatment. Pocks may affect the conjunctiva, but usually heal without affecting sight. The eyes may be closed by oedema as the rash reaches its height. Eye toilet using sterile saline is then helpful. Chloramphenicol eye ointment may be given for short periods of time if secondary bacterial conjunctivitis occurs.
As the fever subsides and the rash begins to heal, the patient will gradually become more mobile. Emotional support may be required at this stage, especially if there is significant facial scarring.
The need for continued isolation, until scabs have all been shed, may also be very trying for patients who are mobilising well. The last deep scabs (or 'seeds') tend to remain in the thick skin of the soles of the feet. In some circumstances it may be beneficial to remove these, using a needle to release them from hardened pockets of skin. The patient who is free of scabs can be released from isolation.
Smallpox care centres
Buildings suitable for use as smallpox care centres will be identified in each Region in Scotland, at Alert Level 0, by the RSDRG.
Minimum specifications for these facilities and procedures for transport of patients are summarised in
Appendix 6.
RSDPGs will identify, at Alert Level 0, doctors, nurses and support staff who would be willing to work in smallpox care centres. Ideally they should have been previously vaccinated so that they could be revaccinated with a faster immune response and a lower incidence of side effects.
Observation and treatment wards will be maintained separately to ensure that possible cases are not exposed to infection.
All possible and probable cases will be vaccinated on admission to protect them from infection by confirmed cases if the diagnosis of smallpox is subsequently excluded.
Contacts: classification and management
Rapid identification and tracing of contacts is essential since vaccination should be carried out as soon as possible, and at most within 3 days of exposure to infection, because the degree of protection diminishes as the interval between exposure and vaccination increases. Contacts should be checked for symptoms before vaccination, to ensure that they are not co-primary cases.
If the diagnosis of smallpox in possible or probable cases is subsequently excluded, contacts who have been identified but not yet traced need not be vaccinated or followed up further.
Primary contacts are persons who have had contact with confirmed cases of smallpox during the infectious period or contaminated fomites. As a precaution, the infectious period should be regarded as from 24 hours prior to the first recognised symptoms until the last scab has been shed.
Primary contacts may be divided into two categories, A and B according to their risk of infection. These categories should be regarded as a guide:
individuals' risk of infection should always be considered in the context of the proximity and duration of exposure.
Contacts may be
asymptomatic or
symptomatic. Symptomatic contacts are people who fit the contact definitions, and in addition have prodromal symptoms that may indicate early smallpox infection. These are prolonged high fever (above 38
OC) and/or constitutional symptoms such as prostration, severe headache or backache, rigors and generalised maculopapular rash.
Secondary contacts are people in close contact with category A primary contacts.
Category A primary contacts (highest risk of infection)
Definition
These are people who are likely to have been exposed to infection through large droplets or contaminated fomites. They include:
Category A contacts should be vaccinated as a
matter of urgency.
Category A contacts must be
formally monitored for the development of symptoms for a period of
16 days from the last exposure to an infectious case.
Formal monitoring involves
daily recording of body temperature, measured orally, and
daily reporting of this, and the presence of other constitutional symptoms to a designated
Smallpox Contacts Telephone Number, which will be dedicated solely for this purpose. Arrangements for establishing this are described in
Section X.
An oral thermometer (preferably a plastic model that can be disposed of after the formal monitoring period), a temperature chart, instructions on the measurement and recording of body temperature, general advice, and the Smallpox Contacts Telephone Number will be provided (see
Appendix 17). In addition, a mobile telephone will be provided to those who do not have access to a mobile or land telephone at home.
Category A contacts who fail to make their daily health report will be actively traced, by telephone or in person.
Restrictions on activity
Category A contacts who develop a fever or other constitutional symptoms must stay at home and immediately telephone the Smallpox Contacts Telephone Number.
The
Restriction Period is the time during which category A contacts are at greatest risk of developing symptoms and becoming infectious. The incubation period for smallpox is usually 10 to 16 days, and as a precaution patients should be regarded as infectious from 24 hours prior to the first recognition of symptoms.
The Restriction Period therefore extends from
9 days after the first exposure until 16 days after the last exposure to an infectious case. During this time, restrictions on activity of category A contacts apply, they must:
Outside the restriction period, and as long as they are well, category A contacts may continue normal activities, although they must not travel abroad and should be advised to stay within their local area until the end of the formal monitoring period and until their vaccination site has completely healed.
There is no legislation to enforce compliance with restrictions on activity. However, in what will be a mainly susceptible population, the onset of symptoms in smallpox cases will be rapid and debilitating, and the patient is unlikely to continue their normal activities.
Action to be taken in the event of symptoms
Category A contacts who develop prodromal symptoms (see paragraph 147) should be regarded as possible cases and transferred immediately to the observation ward of a smallpox care centre. Those who also develop a vesicular rash should be regarded as probable cases and transferred to the treatment ward.
Category B primary contacts (lower risk of infection)
Definition
These are people who have a lower chance of having been exposed to infection via aerosol. They include all persons who have shared rooms or other enclosed spaces with infectious cases of smallpox, and who do not fall into the groups of face to face or fomite contacts described in paragraph 149.
These may include work colleagues, and people who have visited the same premises or travelled on the same public transport (buses, trains, tubes and planes) as smallpox cases. People who have shared air-conditioned buildings with infectious cases should be managed as category B contacts. Note however that transient or distant contacts (see paragraphs 173 to 177 should not be managed as category B contacts. NSOCC will provide further advice as required to assist identification of category B contacts.
Management and monitoring
Category B contacts should be vaccinated unless they have contraindications in which case the risk from vaccination should be weighed against the risk from disease (see paragraph 186).
Category B contacts do not require formal monitoring. However, their details should be recorded, and they should be given an advice sheet (see
Appendix 17) including the Smallpox Contacts Telephone Number (see
Section X) that they must call immediately if they develop a fever or other constitutional symptoms during the 16 days following their last exposure to infection.
Restrictions on activity
Category B contacts who have a fever or other constitutional symptoms must stay at home and call the smallpox contacts telephone number. Otherwise no restrictions on activity are necessary although they must not travel abroad until they have been free of symptoms for 16 days following their last exposure to infection, and until their vaccination site has completely healed.
Action to be taken in the event of symptoms
Category B contacts who develop prodromal symptoms (see paragraph 147) should be regarded as possible cases and transferred immediately to the observation ward of the smallpox care centre. Those who also develop a vesicular rash should be regarded as probable cases and transferred to the treatment ward.
Secondary contacts
Definition
These are people who will have ongoing household contact with category A primary contacts during the formal monitoring period.
They may therefore be exposed to infection if the primary contact becomes symptomatic. They include all persons usually resident at the same address as the primary contact, and other visitors who will be required to spend substantial periods of time at this address during the formal monitoring period.
Management
All secondary contacts of category A contacts should be vaccinated.
If they have any contraindications to vaccination (see
Appendix 9) then they should avoid contact with the primary contact until the primary contact's vaccination site is completely healed because of the risk of transfer of vaccinia infection. This may mean leaving the house.
No monitoring or restrictions on activity are necessary unless the primary contact becomes symptomatic, and therefore becomes a possible or probable case.
If smallpox is confirmed in the primary contact, then the secondary contacts become category A contacts themselves and must be managed accordingly.
Transient and distant contacts (no risk of infection)
There may be large numbers of people who are concerned about having been exposed though brief or remote contact with smallpox cases but who do not fall into the groups of face to face or fomite contacts described in paragraph 149 or the group of category B contacts described in paragraph 162, and are therefore not at risk of infection.
These may include passing contacts for example in the street or shops, and people who have spent short periods of time in large well ventilated areas with smallpox cases.
These individuals do not need to be traced and do not require vaccination. However, they may identify themselves once details of the case become public. Their details should then be recorded, and they should be given an advice sheet for reassurance (see
Appendix 17).
These individuals should not be offered vaccination because this would divert resources away from the essential measures of tracing and vaccinating all category A and B contacts.
If they develop fever or other constitutional symptoms they may call a
Smallpox Advice Line (not the Smallpox Contacts Telephone Number), which will be set up for providing advice to the general public.
Identification and tracing of contacts
SDEs, RSDRTs and clinicians at Smallpox Care Centres will establish the time from which cases of smallpox have been infectious. They will then:
Information about household contacts and the patient's movements during the infectious period will be passed to the RSDRG or RSOCC for further investigation and action.
Vaccination and monitoring of household contacts can be arranged immediately. Other category A and B contacts will need to be traced urgently so that vaccination and monitoring can be arranged. This will be done through CPHMs (CD&EH). TB nurses and Health Advisors have considerable experience at this, which may be usefully employed.
It may be possible to trace contacts through official lists and social networks. However, if this is not possible, consideration should be given to a making a public announcement asking contacts to identify themselves. This should be done with consideration to maintaining the confidentiality of smallpox patients.
A
Smallpox Contact Tracing Number (see
Section X) will be required so that contacts can identify themselves to RSOCC. They may also identify themselves to their GP or through the NHS Helpline or NHS24, which will help to categorise contacts by using telephone triage to grade individuals' risk of exposure to infection.
Once arrangements for formal monitoring of category A contacts have been made, secondary contacts can be identified.
Full details of all contacts identified will be recorded on a database along with the management and outcome of each.
Vaccination of contacts
Contacts should be assessed for contraindications prior to vaccination. They should also be examined for active skin conditions and other medical disorders that may be confused with smallpox, so that the occurrence of new symptoms can be distinguished.
There are
no absolute contraindications to vaccination. Contacts with relative contraindications should be assessed to determine whether the risk from disease outweighs the risk from adverse effects of vaccination. This will be done at Smallpox Vaccination Centres by vaccinators with access to expert immunological advice. If vaccination is indicated, depending on supplies, they may be given Vaccinia Immunoglobulin (VaIG - see
Appendix 13) to prevent vaccine complications. Adverse effects may be treated with cidofuvir - see
Appendix 14.
Arrangements for vaccination
Vaccination will be carried out at
Smallpox Vaccination Centres - see
Appendix 8. Suitable sites will be identified by RSDRGs at Alert Level 0 so that Centres can be activated immediately if required.
Arrangements for the distribution (see
Appendix 11) and administration (see
Appendix 12) of vaccine must ensure the security of vaccine supplies and staff. Information, consent forms and certificates for vaccinees are in
Appendix 16.
Vaccination of different groups (healthcare, emergency and essential workers, and contacts) will be required, and a strict triage system will be necessary to ensure prioritisation of vaccine supplies.
All those vaccinated will be
assessed on the third day following vaccination to determine whether a papule has formed (see
Appendix 12).
Category A contacts will be asked to return to the Smallpox Vaccination Centre for assessment of their papule by a trained clinician. Category B and secondary contacts will be given written instructions describing what the papule should look like. They need only return to the Smallpox Vaccination Centre for professional assessment if they are concerned that their papule has not formed.
Vaccinated individuals shed vaccinia virus until the pock has completely healed.
Individuals who have been vaccinated should avoid contact with others who may be at risk from vaccinia. These are: people who are immunosuppressed, people with eczema and pregnant women. Individuals with these disorders who normally live in the same household as vaccinees should move to alternative accommodation.
Unimmunised primary contacts
These include primary contacts who refuse vaccine, fail to respond to vaccination, or who are vaccinated late (more than 3 days after their first exposure to infection).
Primary contacts who fail to show a response to a first dose of vaccine after 3 days should be revaccinated and the dose discounted.
Non-responders and those vaccinated late may be given
additional prophylaxis against smallpox concurrently with (re) vaccination in an effort to attenuate disease. Supplies of additional prophylactic treatments should be prioritised to those most at risk of disease: