Of pox and pigs: Ripping yarns from the real world of public health disease control

These are notes from a talk presented by Dr Kath Weston, Senior Lecturer in Public Health, Graduate School of Medicine, University of Wollongong. Theses notes were written by me (Dr Matthew Berryman), and are released under the Creative Commons Attribution 3.0 Australian licence.

Kath’s talk was on tales from her time working for the NSW Public Health Division, in the Nepean Blue Mountain (NMB) and Western Sydney (WS) Regions, which were separate, then merged, and are now separate but centrally managed with 2 offices, in Penrith and Parramatta.

The first part of her talk was on measles outbreaks, and listed the following general measures used:

  • Urgent testing.
  • Assessing the public health risk (based on infectious period)
  • Ring fencing of the infection
  • Contact tracing: GP waiting rooms, EDs; and follow up preventative measures.
  • Prophylactic MMR vaccination can be given within < 72 hrs.
  • IG (immunoglobulin) can be given within < 7 days
  • Mass clinics
  • Provision of information
  • Exclusion from school also possible as a strategy, covered under the Public Health Act

The remainder of her talk was a series of case studies.

Wentworth measles outbreak in 2003, case study:

  • The index case was a traveller returning from Nepal. Two visits to the ED; isolated on the first attendance but not on the second because he had assured them he was vaccinated.
  • Case 2 was the baby of case 3 (the father), only 6 weeks old.
  • Case 4 was the child of case 3, 15 months old. The family were conscientious objectors but the mother was immunized as a child, however her immunity wasn’t conferred as temporary immunity via breast milk. The parents refused IG treatment for the 15 month old.
  • The child (I presume both? I can’t recall) was taken to a Queensland caravan park with the mother, this was then Queensland Health’s problem.
  • Case 5 was an ED staff member, who didn’t realize they had measles.
  • Case 6 child attending ED 4 years old.
  • Airborne virus so ask for ED lists up to 2 hours after patient was present
  • Case 7 another hospital worker.
  • Case 8 from case 6 at church.
  • Case 9 from case 8 at video store.
  • 496 contacts total (excluding the church). Note that these are contacts, not cases.
  • 500 contacts at the church (the information provided to church members was in Arabic, I am guessing Christians from Lebanon/Syria??).
  • Public Health needed to drive out to contact people in some cases.
  • The strain was genotyped as D8(Janakpur NEP/2.99/1).
  • In another outbreak there were two genotypes of measles present, so they established that there were 2 outbreaks coinciding.
  • None of the cases had a well-documented vaccination history. The ED staff member thought she/he was vaccinated and declined the hospital vaccination on employment.

2006 outbreak via Amma (Mātā Amṛtānandamayī Devī, a Hindu spiritual leader) on her 2006 Australian tour:

  • She and her entourage weren’t objectors, and Amma herself didn’t have it, maybe one of the entourage had it.
  • Many devotees were, however, objectors, and many around Australia got infected. Contacts refused MMR.

2011 outbreak:

  • No secondary cases after follow up.
  • High school clinic in WS, many students of Pacific Islander without / with no documented measles vaccination.
  • Cost of PHU follow-up of one case of measles: $2433
  • $48,000 total cost of outbreak.

Swine Flu ’09:

  • Strategies used (in order, with dates given): Alert (pre-24/4), delay (24/4), contain (22/5), protect 17/6, sustain, control with vaccine.
  • On June 1 2009 the Pacific Dawn cruise ship arrived in Sydney. Swine flu was confirmed only after people got off the boat, 3 crew members affected.
  • On June 3 2009 the State of Origin was held.
  • Melbourne had the largest outbreak.
  • A woman travelled back to Sydney from Melbourne, and her 10 y.o. son developed symptoms on Tuesday 9 June.
  • He attended on 9th and 10th in a large class (75 children, 9 adults) for some event.
  • Public Health used the Incident Command System (ICS) to manage people and processes.
  • In ICS everyone knows their position (in the case of Kath, she was the boss of her line manager, which didn’t cause any issues), and knows the processes already through training, thus allowing quick action.
  • The 75 children had different play times and a lunch time set, and didn’t mix with others in school (wasn’t clear from the talk how this was enforced).
  • There was a large role for pharmacists, who were needed to weigh children and mix up the required (liquid) dose of Tamiflu.
  • A parent was required at the clinic that was set up for consent— this was another possible vector.
  • Needed to carefully plan the process and layout of the clinic.
  • Contain phase looking at high risk (of poor outcomes) groups: ATSI, pregnant, morbidly obese.
  • Total cost (for Public Health) was $5m.
  • There was a lot of panic, even among GPs.

Other case studies presented:

  • Red-bellied black snake at a childcare. No children bitten.
  • People attending a medical clinic got a rash when visiting the clinic, it turned out it was hairs mistletoe caterpillars in the tree outside of the clinic shedding. Published in Balit et al. Outbreak of caterpillar dermatitis caused by airborne hairs of the mistletoe browntail moth (Euproctis edwardsi).
  • Bats and Australian Bat Lyssavirus, a disease related to rabies and, like rabies, fatal unless treated. Two boys, who found the microbats, and thought they were babies of regular size bats, decided to look after them and took them to the local Coles supermarket to get food for them, however the bats smelt the fruit in the fruit and veg. section and escaped. The boys and Coles staff were scratched. The boys only told parents after one was starting to get symptoms, and were treated with IG and vaccines. Edit: see the comment by Maddy below, but essentially microbats are carnivorous so it was not the fruit that attracted them, but rather that their bodies had warmed up to break torpor. And no reports of ABLV in NSW; I am not sure on the discrepancy between that and what I heard in the talk. I would welcome anyone who knows where stats on human ABLV infections (even though 0 for NSW) are to be found. Stats on ABLV infections in bats can be found here; thanks to my commenter Maddy for that link.
  • An outbreak of Chlamydophila psittaci (birds the vectors) in the mountains. 95 suspected or confirmed cases. Tourism involved as well as usual. Public Health asked for reports of dead birds, one man called up to report he’d ridden his lawn mower over six birds. This outbreak generated lots of hypothesis about contact and other factors that were risk factors. In general, under diagnosis is likely.
  • 14 cases of salmonella from fried ice cream at a restaurant. The source: egg farm. The preparation for fried ice cream consists of deep frozen ice cream coated in raw egg, then placed in crumbs, then it’s put back in the freezer, until cooked quickly in hot oil. In this case the oil was not hot enough to properly cook the outer layers (including the egg layer), and patrons reported that it tasted soggy rather than crisp, indicating this was so.
  • Scombroad poisoning from fish that have partly decomposed (but are still not “bad” in the sense that they don’t appear off) and contain histamines, so they generate an allergic reaction.
  • There were a series of cases of disease that were, after a complex investigation, traced to the lack of autoclaving done at a colonic irrigation clinic; one client tested positive for Hep. C.
  • Bindeez beads poisoning: a cheap version of a glue was used by a local distributer, that metabolised into GHB (γ-Hydroxybutyric Acid, a.k.a the date rape drug). Not good for young kids.
  • Global warming is changing patterns of bird migration, insects, as vectors of disease.
  • Tory Shepherd’s article on Melanie’s Marvellous Measles got a feature, as well as a brief outline of the book itself. The presenter (Kath) thought that Stephanie Messenger was just ill-informed, not crazy. I’ll forward her some of Stephanie’s emails to show her otherwise. :)

Her talk finished with cases where smallpox samples had turned up in historical records. It’s important to note that, given the dates, it was unclear if this was actual smallpox, or more likely (given the descriptions) Variola minor or Vaccinia (cowpox). The use of Variola minor was banned in 1840s (in England) due to the availability of Vaccinia as a safer alternative (“variolation” carried the risk of transmission of other diseases such as Syphilis).

  • A 2003 report of smallpox material found in an 1888 book on civil war. “Scabs from vaccination of W.B. Yarrington’s children”.
  • The Bizarre bits exhibition. ‘ “Dear Pa…the piece I inclose is perfectly fresh and was taken from an infant’s arm yesterday…” read the letter. “Dr. Harris says the inclosed scab will vaccinate 12 persons, but if you want more, you must send for it. I will pin this to the letter so that you cannot lose it as you did before.” ’
  • A parcel delivered to Public Health in 2011 from the NSW State Archives. The letters enclosed with the unopened sample mentioned smallpox. Patient surveillance for staff at Public Health and State Archives was carried out. PCR on the sample was conducted, and no DNA was detected; there were no infections. The source of the sample was the Parramatta Female Factory (convicts, now in Westmead Hospital) used as a pool of recipients to keep the vaccine going in a population (needed scabs to transfer).
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爸爸和老公和博士。Beloved students, change is inherent in all compound things. Strive on with diligence.
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5 Responses to Of pox and pigs: Ripping yarns from the real world of public health disease control

  1. Caroline Shipley says:

    So… at the colonic irrigation clinic, do they ask if you want HepC with that?

  2. Maddy says:

    grumble … “. Two boys, who found the microbats, and thought they were babies of regular size bats, decided to look after them and took them to the local Coles supermarket to get food for them, however the bats smelt the fruit in the fruit and veg. section and escaped.”

    This is an assumption that is unwarranted and not the kind of thing you would do about a medical matter (I hope).

    Microbats are insect eaters. Smelling fruit and veg is not likely to do much for them. It’s more likely that the bats warmed by while the boys were holding / carrying them,and then decided to take off.

    Microbats need to warm up before activity because they can (and do) fall into torpor, even during warm weather as a way of conserving both energy and hydration.

    If bats have been injured or found away from their night roost they may not be in torpor but will be more likely to be able to be active when after being warmed.

    There have been no human infections with ABLV in NSW so whatever symptoms the child displayed, they were not ABLV symptoms.

    • Thanks for the info on both microbats and on ABLV. I’m an expert in neither bats nor ABLV, I was simply reporting on what I heard at the talk, by someone who worked in NSW Public Health, and presumably was somewhat knowledgable about ABLV but not on bat behaviour. I’m not sure on what basis they made the diagnosis (PCR or other?) or on reporting.

      • Maddy says:

        LOL I am ONLY good on bats and a little on ABLV. Yes you are right, most PH people know nothing about bat behaviour which is a shame because it would assist them to more accurately assess contact situations.

        However … once symptoms start with ABVL, there isn’t any effective treatment. I doubt (as there was a delay in reporting) that they were able to test the bats. Also relevant, only one species of microbat has ever been reported to have ABVL (Yellow-bellied Sheath-tail Saccolaimus flaviventris). They are lovely looking bats but very uncommon in towns and cities as they are not tolerant of disturbed environments.

        Other microbats are thought to carry ABVL and _all_ bites and scratched should be treated as though they are potentially infectious however testing of various species has not found infection.

        All of the big bats (the 4 flying-foxes) have been found to carry ABVL.

        In the absence of an animal to test, treatment is initiated because although there is a low risk, the consequences are very very high. Treatment is vaccine and (for people not already vaccinated) RIG. Full details here http://www.health.gov.au/internet/immunise/publishing.nsf/Content/handbook10-4-16

        Anyone who is bitten or scratched should immediately wash (not scrub) the site with soap and water for at least 15 minutes, finally treat with pov iodine. This is the prophylaxis much of the world relies upon and it appears to be very effective (http://www.who.int/mediacentre/factsheets/fs099/en/)

        The ABS have annual stats in the year book – but not cumulative.

        The answer on how many people infected is 3 – A woman died in 1996, another woman in 1998 (after a 22 month incubation period) and a 8 year old child, Lincoln Flynn, died in February 2013. All these three people were infected in coastal northern Queensland.

        The first woman was a rehabber. ABVL had either not yet been identified or had just been identified, she was not vaccinated. The second woman was offered vaccination but through some confusion didn’t take it up. The young child didn’t tell his parents and thus they never had the opportunity to seek care for him. Lincoln’s parents are setting up a foundation in his honour to promote awareness – https://www.facebook.com/groups/lyssavirus/

        Talk to your children. Teach them that bats, big and small, are great, not scary, cute and very, very smart buttons, fantastic for the environment and they sometimes need our help. But they are never, ever, ever, for touching. Teach them “don’t touch, do tell” (parents, rehabbers). We can remove an uncontained bat from a situation, providing a service to the bat and to the public.

        Finally, on a lighter note you may see from the bat stats, ABLV is much more common in Qld than anywhere else. Even if one removes the peaks associated with research testing, still they have a much higher rate of ABVL. Flying-foxes are very mobile individuals, from Melbourne to Brisbane, to the tweed or up to Marybough. Not withstanding this mobility there is more ABLV found in bats in Qld than anywhere else. One might think it’s a testing bias except that rehabbers talk – more animals come in with ABVL in Qld than do in NSW. And more come in in Northern NSW than around Sydney. No one knows why but it would be something interesting to study one day. I have no idea if there is a similar geographically effects seen in countries with rabies.

        Anyway, more than you expected ever to think about bats and ABLV.

      • Oh, I love bats. Amazing creatures, and thank you for all the information, particularly on what to teach kids; we’re still fairly new to NSW (from SA, where there aren’t nearly as many bats around), so it’s handy to add that to my knowledge of wildlife.

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