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Preference: Infectious Diseases and Parasitology

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Explainer: what causes necrotising fasciitis, the flesh-eating bug?

Port Melbourne VFL player Sam O’Sullivan is reportedly recovering in hospital after being infected with the flesh-eating disease “necrotising myositis”. This disease is one of a group of serious infections affecting soft tissue, usually called “necrotising fasciitis” or sometimes “gas gangrene”.

Like many medical terms, necrotising fasciitis is simply a descriptor. Breaking this down into its parts, it is inflammation (“-itis”) due to an infection of the fascia (the lining between the skin and the underlying muscles) that causes death of the tissues (necrosis).

The key concept here is the body structures that are affected. Those infections that affect the skin and superficial tissues, termed “cellulitis”, are generally mild.

But when they affect the deeper fascia and muscles (“myositis”), they can spread very quickly and cause severe illness. Because the action is occurring at a deeper level, there may be few or no changes to see on the surface.

Major complications of necrotising fasciitis include extensive loss of skin or deeper tissue (sometimes resulting in loss of the limb), and severe stress on the body’s organs (resulting in organ failure). For a rather graphic example of skin damage, click here.

Around a quarter of patients with necrotising fasciitis will die of their infection, but this varies with the severity of the infection and the underlying health of the patient.

What causes it?

Necrotising fasciitis is caused by bacteria that gain access to the body, usually by damage to the skin, the first line of protection.

Quite a few different types of bacteria can cause the disease. However, when they cause infection elsewhere, many are only associated with mild disease. These include group A streptococci, a common cause of tonsillitis, and Clostridium perfringens, a cause of food poisoning.

Contrary to many news reports, it is not caused by viruses – there is no flesh-eating virus.

Around 400 cases of necrotising fasciitis are diagnosed in Australian hospitals each year, which is similar to the incidence reported in other countries.

How is it contracted?

As with many infectious diseases, three factors interact to produce an infection: factors related to the bacteria; factors related to the patient; and factors relating to the environment that brings them together – in this case, the nature of the injury.

Patient factors associated with infection include impaired immunity, obesity and chronic diseases such as diabetes.

Many patients report a preceding breach in the skin, through things such as surgery, accidental wounds, or intravenous drug use.

Some types of infections are associated with particular settings. For instance, injuries occurring in marine environments, such as coral cuts, can be associated with particular types of bacteria that live in watery settings (such as Vibrio or Aeromonas).

Similarly, severe infections associated with intravenous drug use may be due to contamination of the injected substances.

In the past, gas gangrene was a common complication of battlefield injury, as wounds were often contaminated with dirt and there were delays to surgical treatment and access to antibiotics, if these were available at all.

Some strains of bacteria produce toxins that can enable them to spread readily through tissue. Group A streptococci, for instance, produce a toxin called cysteine protease SpeB, which may allow the bacteria to dissolve tissue and evade the immune system.

Group A streptococci also produce a range of other toxins but their role and function are not well understood.

How is it recognised?

Unfortunately, early necrotising fasciitis is easily missed. This is because the symptoms – fever, pain, swelling and tenderness at the affected site – may be non-specific or confused with a mild, superficial infection.

The hallmark of necrotising fasciitis is pain far more severe than expected for what might otherwise look like a minor infection. As the infection progresses, the skin becomes tense and discoloured, and patients may become severely unwell with low blood pressure and confusion.

Occasionally, some bacteria produce gas and this can be felt as “crackling” under the skin. The infection can spread quickly – over minutes to hours – and deaths have been described within 24 hours in otherwise healthy people.

How is it treated?

The most important treatment for infections such as necrotising fasciitis or myositis is surgery to remove the dead tissue and as much of the bacterial burden as is possible.

The decision to operate involves careful clinical judgement – not every skin infection needs surgery and clearly no-one wants surgery for an otherwise simple infection. However, if necrotising fasciitis is truly present, early surgery can be life-saving. In some cases, surgery may result in amputation or require extensive skin grafting.

A combination of different antibiotics is usually used. A range of different bacteria may be implicated and each requires different antibiotics. Some antibiotics may also help switch off the toxins produced by bacteria.

There is some interest in other secondary treatments, though these should be considered only after getting the patient to surgery, supporting failing organ systems and quickly administering the correct antibiotics. Hyperbaric oxygen delivered in specialised compression chambers, for instance, aims to preserve living tissue and help the immune system combat infection. However, there is little good evidence that this helps.

Similarly, intravenous immunoglobulin is a serum protein pooled from blood donors that may “mop up” toxin. It is sometimes given for some types of necrotising fasciitis, although the evidence that it helps is also conflicting.The Conversation

This article was originally published on The Conversation. Read the original article.

Photo: Group A Streptococcus bacteria. NIAID/Fickr

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[Comment] Understanding death, extending life

One of the biggest contributors to preventable deaths isn’t a health problem but a record-keeping problem—and it is one that can be solved. According to WHO, nearly two-thirds of all deaths—38 million each year—go unreported.1 Millions more deaths lack a documented cause. Many countries do not have complete birth records, while others lack reliable data about risk factors associated with poor health and non-communicable diseases—for instance, rates of tobacco use or access to nutritious food.

[World Report] Profile: Southern Africa Consortium for Research Excellence

That diseases need to be studied in their local environment, is not lost on Malawi-based clinician–scientist, Moffat Nyirenda, and director of the Southern Africa Consortium for Research Excellence (SACORE). At SACORE, he strives to strengthen the region as a robust research base so that communicable and non-communicable diseases (NCDs) can be rigorously studied in the local setting.

[Review] Consolidating the social health insurance schemes in China: towards an equitable and efficient health system

Fragmentation in social health insurance schemes is an important factor for inequitable access to health care and financial protection for people covered by different health insurance schemes in China. To fulfil its commitment of universal health coverage by 2020, the Chinese Government needs to prioritise addressing this issue. After analysing the situation of fragmentation, this Review summarises efforts to consolidate health insurance schemes both in China and internationally. Rural migrants, elderly people, and those with non-communicable diseases in China will greatly benefit from consolidation of the existing health insurance schemes with extended funding pools, thereby narrowing the disparities among health insurance schemes in fund level and benefit package.

Fever and rash from Timor: where have you been and when?

Clinical record

A 61-year-old American aid worker was transferred to Royal Darwin Hospital from Timor-Leste with fever and rash. He had worked in Timor for 1 year and was in good health apart from an episode of falciparum malaria treated 9 months previously. He described headache, myalgia and fatigue for 7 days, and 6 days of fever and chills. On Day 2 of illness, he attended a Timorese clinic where an unidentified blood test was reported positive for falciparum malaria. Despite initial treatment with sulfadoxine–pyrimethamine and 3 days of atovaquone–proguanil, his fever and chills persisted. After a further positive test result for falciparum malaria at the same laboratory, he attended a referral clinic on the same day, where thick film blood examination and a histidine-rich protein 2 antigen test were negative for malaria. He was noted to have an erythematous truncal rash and switched to artemether–lumefantrine. Because of ongoing fever, he was evacuated to Australia with provisional diagnoses of malaria or, given the rash, dengue fever.

On arrival at our hospital, the patient had a temperature of 38.3°C; oxygen saturation of 94%; a confluent, macular, blanching, non-pruritic rash on his trunk (Figure); and a fine, petechial rash on his ankles. He had bibasal inspiratory crackles but no peripheral oedema. A chest x-ray showed small bilateral pleural effusions. Admission haematology showed anaemia (haemoglobin level, 131 g/L [reference interval (RI), 135–180 g/L]); thrombocytopenia (platelet count, 17 × 109/L [RI, 140–400 × 109/L]); normal total white cell count (4.4 × 109/L [RI, 4.0–11.0 × 109/L]); lymphopenia (lymphocyte count, 0.4 × 109/L [RI, 1.0–4.0 × 109/L]); and neutropenia (neutrophil count, 0.4 × 109/L [RI, 2.0–8.0 × 109/L]). Blood films were negative for malaria parasites but showed band forms, toxic granulation and reactive lymphocytes. A repeat histidine-rich protein 2 antigen test for Plasmodium falciparum returned a negative result. His alanine aminotransferase level (67 IU/L; RI, < 34 IU/L), creatinine concentration (142 μmol/L; RI, 46–99 μmol/L) and activated partial thromboplastin time (51 s; RI, 26–41 s) were all elevated.

Further history revealed that his symptoms had commenced on arrival in Bali en route to Timor, after a 4-week holiday on his orchard in Seminole County, Florida, United States. On specific enquiry, he described multiple tick bites over a 1-week period up until 4 days before symptom onset. With this information, the differential diagnosis shifted to tick-borne infections, with Rocky Mountain spotted fever (RMSF) and erhlichiosis considered most likely. Treatment with doxycycline was commenced promptly (200 mg loading dose followed by 100 mg twice daily) and continued for 5 days after defervescence. Within 72 hours, his symptoms improved, with resolution of fever, rash, thrombocytopenia, renal impairment and coagulopathy.

Serological tests for dengue fever virus and Rickettsia rickettsii (RMSF) on paired sera were negative. Dengue NS1 antigen testing and blood cultures were negative. Serology (IgM and IgG) by microimmunofluoresence for Ehrlichia chaffeensis showed a titre increase from 1 : 512 to 1 : 8192 over 8 days. Q fever and rickettsial serological tests were negative. The patient was also tested for Anaplasma phagocytophilum, another tick-borne infection endemic to the US which can present with a similar illness. Paired sera showed an increase in A. phagocytophilum titres from 1 : 256 to 1 : 2048. The lower titre rise compared with E. chaffeensis was considered to most likely represent a cross-reaction rather than dual infection.1

We did not look for intracytoplasmic morulae characteristic of E. chaffeensis infection using buffy coat examination, as it is considered insensitive compared with serology.2 The combination of serological, clinical and laboratory findings supported a diagnosis of human monocytic ehrlichiosis acquired in the US.

Ehrlichia chaffeensis, an obligate intracellular pathogen in the Anaplasmataceae family, is a tick-borne pathogen found predominantly in the southern and eastern states of the US.1 It is not endemic in Australia or Timor-Leste, and ehrlichiosis has not previously been reported in Australia (although Anaplasma platys has been found in Australian dogs). After propagation in monocytes, it causes fever, headache, myalgia, thrombocytopenia and leukopenia, with rash occurring in about 30% of cases.1,2 Complications include shock, meningoencephalitis, coagulopathy, acute kidney injury and cardiac failure.1,2 Reported mortality is about 3%, with fatal outcome linked to age and delayed diagnosis and treatment.1,2 Human monocytic ehrlichiosis shares many clinical features with the other US tick-borne rickettsial and rickettsia-like diseases, RMSF and anaplasmosis, with rash more common in RMSF but rare in anaplasmosis. While these may be difficult to differentiate,2–4 all respond well to doxycycline but not to β-lactam antibiotics.2

This case illustrates the importance of obtaining a complete travel and exposure history when assessing febrile travellers, and not just their most recent travel. A reliance on the most recent area of residence and failure to obtain a history of US tick bites led to initial misdiagnoses of malaria and dengue fever, and delayed the initiation of treatment with potentially life-saving doxycycline. The initial unidentified positive malaria diagnoses in an unaccredited Timorese clinic laboratory were not reproducible and were thought to have been false-positives. False-positive microscopy and overdiagnosis of malaria is common in malaria-endemic areas.5 The timing of symptom onset, acute kidney injury and left shift and toxic granulation on blood films4 were not suggestive of dengue fever (nor the rash or left shift for malaria), and all provided further clues to the correct diagnosis.

Lessons from practice

  • Always obtain a complete travel and exposure history when assessing febrile travellers, and not just their most recent travel.

  • Reliance on most recent travel in a malaria- and dengue-endemic area led to erroneous diagnoses of malaria and dengue.

  • Consider the possibility of tick-borne infections in patients presenting with fever and rash.

  • Early initiation of doxycycline is potentially life-saving in ehrlichial and rickettsial infections with mortality linked to delayed diagnosis and inappropriate treatment.

FigureConfluent, macular, erythematous, blanching rash on the patient’s trunk

A lifetime of jabs to be on the record

The birth-to-death vaccination details of every Australian will eventually be held in a single national register under new laws passed by Federal Parliament.

In a strong show of bipartisan support for the importance of vaccination, the Labor Party on 12 October backed Coalition legislation calling for the establishment of an Australian Immunisation Register to document all the vaccinations received by Australians under the National Immunisation Program.

Under the new laws, the current Australian Childhood Immunisation Register will, from 1 January next year, be renamed the Australian Immunisation Register and expanded to collect vaccination records for all Australians 20 years or younger.

From next September, the Register will be further enlarged to encompass all age groups including, for the first time, 70-year-olds receiving the Zostavax shingles vaccine provided under the National Immunisation Program.

These changes will be complemented by the transformation of the National Human Papillomavirus Vaccination Program Register into the Australian Schools Vaccination Register, which from 2017 will document all vaccinations given to schoolchildren under the National Immunisation Program.

The legislation will also enable the Federal Government to implement its No Jab, No Pay policy by allowing for the sharing of vital Centrelink data.

Assistant Treasurer Kelly O’Dwyer said the changes would remedy serious shortcomings in the nation’s immunisation record which have left some dangerously exposed to serious infections.

“The changes made in this Bill will help to increase national immunisation rates,” Ms O’Dwyer told Parliament. “There are a number of vaccines administered in schools that are not adequately recorded and, as a result, immunisation rates for adolescents in Australia are not well known.”

The Minister said this included information about vaccination for potentially extremely serious diseases such as chicken pox, tetanus, diphtheria and whooping cough.

Ms O’Dwyer said the registers, which will eventually be consolidated into a single, life-long vaccination record, would help identify areas where vaccination rates were low, allowing targeted action.

“The…registers will give vaccine providers the data they need on areas where immunisation rates are low, and it will allow them to send out the necessary reminder letters,” she said.

Shadow Health Minister Catherine King said the legislation would not only help ensure children were being fully immunised, but also adults.

“It is about ensuring adults have information they need to ensure the protection they receive as children continues long after their schooling ceases,” Ms King said. “Diseases like tetanus, diphtheria and, of course, whooping cough, are not confined to children. Adults who travel or come into contact with others who do not keep their immunisations up-to-date are just as much at risk as those who have refused to be vaccinated.”

“Having a register rof people and knowing their vaccination status is an important way to ensure that people can remain vaccinated.”

Adrian Rollins

 

Frugal Aussies show US how it’s done

The efficiency and effectiveness of Australia’s health system has been highlighted by figures showing Americans have more chronic illnesses and worse life expectancy than Australians despite spending more than double the amount on care.

Although the United States spent $US9086 per person on health care in 2013, compared with $US4115 in Australia, the average American was likely to live about two years less and be burdened with more chronic diseases, a study by The Commonwealth Fund has found.

As the Federal Government looks to use the Medicare Benefits Schedule Review to cut health spending, the Commonwealth Fund report shows Australia gets good value for its health dollar, achieving high life expectancy and low rates of infant mortality despite one of the smallest outlays among its rich-world peers.

The investigation found the US spent 17.1 per cent of its national output on health care in 2013 – far more than any of the other 12 high-income countries included in the survey. The next biggest spender was France, where the health bill amounted to 11.6 per cent of gross domestic product.

By comparison, Australia’s health care was a bargain. Its total expenditure was the second-lowest among the 13 countries examined – just 9.4 per cent. This was on a par with Norway and only slightly more than the smallest spending nation, Great Britain (8.8 per cent).

Despite this, Australians can expect to live longer than the average American, and in better health. US life expectancy was 78.8 years in 2013, the lowest among the 13 countries examined and considerably less than the 80.1 years for Australian men and 84.3 years for women recorded at the time.

Not only did Americans live shorter, on average, but they were also sicker. The Commonwealth Fund’s 2014 International Health Policy Survey found that 68 per cent of Americans aged 65 years or older had at least two chronic illnesses, compared with 54 per cent of Australians in the same age group. Just 13 per cent had no chronic conditions, compared with 32 per cent of older Britons.

America’s big spending ways are being driven by the adoption of advanced technology and higher service charges rather than because they are constantly rushing to the doctor.

The Commonwealth Fund found that in the US almost 107 MRI exams are conducted for every 1000 people, compared with a rich world average of 50.6 per 1000 and just 27.6 per 1000 in Australia. Similarly, Americans are more than twice as likely to have a CT or PET scan as an Australian.

Not only were they having more scans, they were paying higher prices for them.

Americans also paid the highest prices for medical procedures and prescription drugs. Data from the International Federation of Health Plans indicates that in 2013 bypass surgery in Australia cost an average of around $US42,130, compared with $US74,345 in America, and drugs in Australia were around 50 per cent less expensive.

Not surprisingly, given the relative expense of seeing a doctor in the US (average out-of-pocket costs were $US1074, second only behind Switzerland), Americans were relatively reluctant to seek care. On average, in 2013 they saw a doctor just four times a year, compared with an average 7.1 times among Australians, and the number of hospital discharges per 1000 people in the US was 126 – well below Australia (173 per 1000).

The consequences of America’s heavy health spending are far-reaching, the Commonwealth Fund concluded, not only driving people into bankruptcy and government budgets into deeper deficit, but holding down wages as health insurance eats further into salary packages.

It added that the imbalance in Government spending caused by America’s burgeoning health bill may actually be making the situation even worse.

The Commonwealth Fund warned that American governments were spending so much on health care it was crowding out other areas of expenditure that could actually improve health, particularly social programs and support.

“In the US, health care spending substantially outweighs spending on social services,” the Fund said. “This imbalance may contribute to the country’s poor health outcomes. A growing body of evidence suggests that social services play an important role in shaping health trajectories and mitigating health disparities.”

It suggested one way to redress the imbalance could be through funding arrangements in which providers are rewarded for health outcomes could make it sensible for insurers, hospitals and others to invest in social services and other interventions.

The Commonwealth Fund study can be viewed at: http://www.commonwealthfund.org/publications/issue-briefs/2015/oct/us-health-care-from-a-global-perspective

Adrian Rollins

 

[Editorial] ICD-10: there’s a code for that

The International Classification of Diseases (ICD) is the system for describing and coding mortality and morbidity incidents, implemented by most WHO member states. As of Oct 1, 2015, the USA formally transitioned to the updated codes, although they have already been in use in 117 other WHO member states (such as China and Canada) since release in 1992. The directive by the US Federal Government for ICD-10 compliance has been a major and controversial administrative and financial undertaking for health-care professionals, hospitals and health centres, and insurance companies.

Giant trade deal will not drive up cost of meds: Govt

Australians will be shielded from any increase in the cost of government-subsidised medicines under the terms of a massive trade deal covering 40 per cent of the global economy, Trade Minister Andrew Robb has promised.

Negotiators from 12 nations including Australia, the United States, Japan, Canada, Vietnam and Mexico concluded talks on the controversial Trans Pacific Partnership agreement after the US agreed to an Australian compromise to protect the Pharmaceutical Benefits Scheme in the face of demands for an extension of data protection for biologic medicines.

AMA officials and other health campaigners had raised concerns that intellectual property provisions proposed during the course of negotiations would have forced up the price of prescription medicines, costing consumers and the Government billions of dollars, and possibly allowed corporations to block public health measures such as anti-smoking laws.

But Trade and Investment Minster Andrew Robb said the final deal recognised Australia’s existing medicines regime and included carve-outs to protect health and environmental policy from action taken under investor-state dispute settlement (ISDS) provisions.

“Importantly, the TPP will not require any changes to Australia’s intellectual property laws or policies, whether in copyright, pharmaceutical patents or enforcement,” Mr Robb said. “Australia’s five years of data protection for biological medicines will remain unchanged. The TPP will not increase the price of medicines in Australia.”

The US had been pushing for at least eight years of data exclusivity for developers of biologic medicines, which are derived from biological sources such as human cells, blood, proteins and antibodies, and are used to treat diseases including cancer and rheumatoid arthritis.

Australian law currently provides for a five-year period of data exclusivity, and the extra years were potentially worth billions to pharmaceutical companies by delaying the entrance of lower-cost rivals the while adding hundreds of millions to the cost of the PBS.

The issue threatened to derail the deal, but US negotiators accepted an Australian counter-proposal to accept the five-year protection period where it exists while giving countries the option to opt for eight years if they so choose.

Prime Minister Malcolm Turnbull hailed the signing of the trade a “very big win”.

Public health campaigner Professor Mike Daube said the provision in the deal preventing tobacco companies from suing countries for anti-tobacco laws was “a quite remarkable and historic development”.

“It’s a huge achievement for public health, and possibly the biggest international setback for the tobacco industry that we have ever seen,” he said. “Tobacco has rightly been singled out as the pariah industry.”

There had been fears that tobacco and alcohol producers would use ISDS provisions to try and prevent governments from implementing public health measures – tobacco companies are already using ISDS provisions in Australia’s trade agreement with Hong Kong to challenge the legality of tobacco plain packaging laws.

The Government has expressed confidence that the finalised deal will prevent this, but intellectual property law expert Professor Matthew Rimmer sounded a more cautious note.

“Drug companies, junk food and soda companies, and alcohol manufacturers could still challenge government policy and regulation,” Professor Rimmer told Fairfax Media. “There is concern that the general defences for public health policy are limited.”

A major gripe of critics has been the secrecy surrounding the negotiations, which Professor Rimmer said had not served public health policy well.

Among those concerned about the health implications of the completed TPP is medical charity Medicins Sans Frontieres, which warned it would limit the access of people in developing countries to vital drugs.

The charity said millions relied on the ability of pharmaceutical companies in places like India to manufacture drugs coming off patent for a fraction of the cost of name brand producers, and the precedent set by the trade deal would impede this.

“The big losers in the TPP are patients and treatment providers in developing countries,” US Manager of MSF’s Access campaign Judit Rius Sanjuan told Fairfax Media. “Although the text has improved over the initial demands, the TPP will still go down in history as the worst trade agreement for access to medicines in developing countries, which will be forced to change their laws to incorporate abusive intellectual property protections for pharmaceutical companies.”

Adrian Rollins