What is typhoid? How do you catch it? And while we’re at it, why have health authorities failed so miserably at communicating with the public over the outbreak?
A woman in Auckland died of typhoid last week and no one was told about it until after the funeral days later. Neither her family nor visiting mourners from Samoa were told it was typhoid, or told about any of the vitally important health safety measures they needed to take. So now at least 18 more people have the disease. It may have spread to two countries.
We asked Mark Thomas, an expert in infectious diseases at the University of Auckland, to explain the dangers of typhoid fever. He emphasised that he did not know enough about the current situation to comment on it directly. But he did tell us this:
Typhoid fever is a potentially fatal illness caused by Salmonella bacteria multiplying within the lining of the small intestine. In the absence of antibiotic treatment most infected people will suffer days or weeks of hectic fevers before the immune system finally eradicates the infection, allowing the person to recover and then be resistant to recurrences.
However, without antibiotic treatment, about one person in 10 will die, as the result of the infection eroding through the wall of the small intestine, leading either to catastrophic bleeding into the intestine, or to leakage of the intestinal contents into the abdominal cavity – peritonitis.
The usual features of typhoid fever are mostly non-specific. Many patients have no abdominal pain and neither diarrhoea nor vomiting. Instead they commonly have constipation, severe shivering attacks, high fevers and drenching sweats. They may have a dry cough and be drowsy.
While doctors will commonly suspect typhoid fever in a person with fever who has recently arrived in New Zealand from a developing country, the only reliable way of confirming the diagnosis is for a microbiology laboratory to grow and then identify the Salmonella bacteria in a sample of blood collected from the patient. This testing will usually take some days and it is quite common for many blood samples to be negative before one finally grows the Salmonella bacteria. The diagnosis therefore may remain uncertain for several days after testing began.
Antibiotic treatment can kill the Salmonella bacteria and cure the patient. In severely unwell patients treatment may be started before the laboratory has confirmed the diagnosis, but in less severely unwell patients the diagnosis may not be suspected and treatment may be delayed.
A small proportion of patients who have recovered from typhoid fever, and had the infection eradicated from their small intestine, are left with persistent infection within the gall bladder. These asymptomatic carriers consistently excrete huge numbers of Salmonella bacteria in their faeces for the rest of their lives.
Their faeces are the usual source of infection for others. Infection cannot be spread by contact with saliva, sweat, tears, vomit or other bodily fluids, and therefore medical precautions to prevent spread are exclusively focused on preventing exposure to faeces from an infected person.
Because faeces are the only source of infection, typhoid fever is now very rare in developed countries such as New Zealand. In contrast, in countries without an effective sewerage system, human faeces can contaminate drinking water, and vegetables or fruit, either while they are growing or when they are being washed after harvesting.
Because Salmonella bacteria are present in such large numbers in the faeces of an infected person, relatively small amounts of faecal contamination can be sufficient to make food or water highly infectious. In many under developed countries, where human faeces may be used to fertilise fields, typhoid fever is a common severe disease of childhood, and most adults are immune as the result of surviving infection in childhood.
In recent decades almost all cases of typhoid fever in New Zealand have occurred in people who have either eaten contaminated food or drunk contaminated water in a developing country, most commonly India or a Pacific Island nation, and then became sick days or weeks later, following their arrival in New Zealand.
These people usually do not spread the infection to others in New Zealand. This is either because antibiotic treatment eradicates their infection, or because if they do continue to excrete Salmonella bacteria in their faeces, the sewerage system is sufficiently good in most parts of New Zealand that there is almost no chance for their faeces to contaminate food or water.
Very occasionally in New Zealand, asymptomatic carriers, or people with typhoid fever, do infect others, when they fail to adequately wash their hands after having a bowel motion, and then prepare food with their unclean hands.
To prevent this happening, the New Zealand public health service does not allow people who have suffered an episode of typhoid fever, and whose occupation involves preparing food for others, to return to work until faeces tests show that the infection has been eliminated.
Mark Thomas is an expert in infectious diseases and an associate professor in the Faculty of Medical and Health Sciences at the University of Auckland.
Typhoid in Auckland: what The Spinoff would like to know
By Simon Wilson
1. The hospital did not discover the deceased woman had typhoid until shortly before, or shortly after, she died, depending on which of their own version of events you want to believe. But as soon as they did know, what did they do?
2. The hospital said it did not announce there was a typhoid outbreak straight away because the family, who were Samoan, had asked it to wait till after the funeral. Since when did the control of infectious diseases place such personal or cultural sensitivity above public health?
3. More to the point, who got it into their heads that “not upsetting” people is more important than warning potential carriers of a contagious disease what they should and should not do to spread it further?
4. The most likely way typhoid is spread in a country like New Zealand is for carriers of the disease to infect food they prepare. Why was the family of the deceased allowed to help prepare the funeral feast?
5. Typhoid cannot be spread by kissing, cuddling or other such physical contact. So why have we listened for days to frightened family spokespeople saying the family did these things with the dying woman and now feared the worst? Why did no one tell them that such behaviour is not dangerous?
6. The people most at risk in this outbreak are Pasifika. Why did the Regional Public Health Service (RPHS) not move quickly to provide clear public health advice through Pasifika churches?
7. Why did the RPHS not move quickly to advise the whole Auckland population of the risks and the measures we should take to mitigate those risks?
8. Why were people from Samoa who came here for the funeral allowed to return home without being testing for typhoid?
9. What has been done now to contain the outbreak?
10. Who is the Minister of Health?
11. Why does he keep telling us he learned about the outbreak on TV and is very worried about the breakdowns in communication blah blah blah. Is he in charge or isn’t he?
12. Why does the myth persist that the “Minister of Health is doing a good job”? All he appears to be doing is quarantining the government: making sure they don’t get blamed when things go wrong in the health system.
13. It’s Jonathan Coleman, btw. He’s ranked number 7 in cabinet. So when is Jonathan Coleman going to take charge of this fiasco, issue the right instructions to ensure the outbreak is curtailed, hose down the misinformation and reassure the populations of two countries that everything that needs to be done is now being done?
14. Is it?
Simon Wilson is the editor of The Spinoff Auckland.
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