Oral, oesophageal and vulvovaginal candidiasis (thrush)

  • Oral thrush occurs in ~2.0 million people worldwide based on ~90% of HIV/AIDS patients not taking but needing anti-retroviral therapy, estimated by the WHO in 2016.
  • Oral thrush also occurs in normal babies, people taking inhaled steroids for asthma, following radiotherapy to the head and neck for cancer, in denture wearers and in some leukaemia and transplant patients.
  • Candida infection of the oesophagus (gullet) affects an estimated ~1.3 million people as ~20% of HIV/AIDS patients are not on anti-retroviral therapy, and ~0.5% if on anti-retroviral therapy develop it.
  • Repeated attacks of vulvovaginal candidiasis affect at least 135 million women annually, The impact of on quality of life is substantial. About 70% of all premenopausal woman develop thrush at some point in their lives.

Invasive and life-threatening fungal infection

Candida infection

  • ~400,000 cases of Candidaemia predicted worldwide, with a mortality of 30-55%.
  • Candida peritonitis about 60,000 – 100,000 cases each year. The mortality of Candida peritonitis was 38%.
  • Around 150,000 of the 7.5 million patients admitted to intensive care (ICU) in Europe, USA and Japan each year grow Candida in their urine and is a common finding in hospitalised patients and those with catheters.

Invasive aspergillosis

  • Over 10 million patients in Europe, USA and Japan are at risk of invasive aspergillosis (IA) each year.
  • Over 300,000 patients develop IA annually.
    • ~10% of acute leukaemia (300,000 new cases annually)
    • stem cell and other transplants (>75,000 annually in the USA, Europe and Japan) (7,500 IA cases)
    • 1.3-3.9% of COPD patients admitted to hospital
    • Worldwide there are 1,242,000 lung cancer cases annually, consistent with an additional 32,600 IA cases.
    • liver failure in China documented a 5% rate, with a 95% mortality

Cryptococcal meningitis

  • 223,100 people develop cryptococcal meningitis in AIDS, each year. 181,100 of these die.

Pneumocystis pneumonia

  • About ~2.2 million HIV/AIDS infected patients who should be receiving anti-retroviral therapy are at risk as well as many other immunocompromised patients
  • Pneumocystis pneumonia has a 10-30% mortality in the USA and UK
  • Prevalence rates in Africa are 10% (South Africa, 2000), 49% (South Africa, 2002), 31% (Botswana, 2003) and 5% (Malawi, 2011). In adults from Africa, rates were 9% (Malawi, 2001), 33% (Tunisia, 2002), 37% (Kenya, 2003), 11% (Malawi, 2007), 30% (Ethiopia, 2008), 4% (Uganda, 2010), 5% (Namibia, 2012). 10% (Tanzania, 2012) and 11% (Uganda, 2012).
  • Precise estimates of annual incidence are difficult because of diagnostic deficiencies but case numbers certainly exceed 400,000 globally per year.
  • Given the number of other patients at risk for Pneumocystis pneumonia and rising rates in the UK and elsewhere in non-AIDS patients, a rough estimate of 100,000 additional cases per year is estimated.

Histoplasmosis

  • In AIDS, disseminated histoplasmosis is a devastating infection and difficult to diagnose rapidly enough to save the patients, even with either rapid antigen or PCR testing. An
    approximation of ~100,000 is likely, with Central and parts of South America most affected, and some cases in Africa and SE Asia.
  • Up to 50 million people are thought to have been infected with histoplasmosis, with ~500,000 new infections each year. About 25,000 cases of symptomatic histoplasmosis are estimated in the USA annually.

Mucormycosis

  • A population estimate from the USA of 2 cases of mucormycosis per million and from France of 0.6 per million. The projected annual incidence is as high as 13 per 100,000.

Coccidioidomycosis

  •  About 25,000 cases of coccidioidomycosis occur in the US each year, but this is thought to a significant underestimate with probably 7 times as many cases (i.e. 140,000-150,000) cases annually. Many more cases occur in Central and South America.

Allergic fungal disease

Allergic bronchopulmonary aspergillosis (ABPA)

  •  Approximately 4.8 million people develop ABPA among the 193 million adults with active asthma worldwide.
  • ~ 15% of people with cystic fibrosis develop ABPA, ~9,000 affected.

Severe Asthma with Fungal Sensitisation (SAFS)

  • SAFS is predicted to affect ~6.5 million (range 3.25-13 million) adults worldwide depending on the frequency of severe asthma (5-20% of all asthmatics).

Allergic fungal rhinosinusitis

  • Allergic fungal sinusitis and rhinitis affects ~12 million people at any time.
  • In Israel, nearly 0.5% of the population (40,000) is thought to be affected. In India, a community survey of allergic fungal rhinosinusitis (FRS) in rural India found a population prevalence of 0.11% of chronic FRS with allergic FRS in 41 (56.1%), chronic granulomatous FRS in 13 (17.8%), eosinophilic FRS in 11 (15.0%), fungal ball in 7 (9.5%) and chronic invasive FRS in one (1.3%).

Chronic fungal disease

  • Chronic pulmonary aspergillosis complicates many respiratory disorders including tuberculosis, ABPA, sarcoidosis and COPD, and so the total burden of this debilitating disorder is ~3 million.
  • There are no global estimates for the Neglected Fungal Diseases mycetoma and chromoblastomycosis. A 2013 survey reported a total of 8,763 cases of mycetoma. The prevalence of chromoblastomycosis varies from 14/100,000 in Madagascar (3,500) to 3/100,000 (6,200) in Brazil and fewer elsewhere. Sporotrichosis is probably more common but very variable in frequency with hyper-endemic areas in Mexico and Peru with rates as high as 25/1,00056

Fungal eye infections

  • Estimates of the annual incidence of fungal keratitis vary from 1 million to 6 million in SE Asia annually. Among causes of avoidable blindness, corneal opacities (caused by fungi or bacteria) accounts for 10% of the 284 million people visually impaired worldwide.

Cutaneous fungal infections

  • Fungal infection of the skin, hair or nails affects ~1 billion people and in the US alone accounted for 4million outpatient medical visits.
  • Fungal nail infection (onychomycosis) is common in the general adult population, probably 5-25% rate with an increasing incidence in elderly people.
  • Athlete’s foot (tinea pedis) is more common than onychomycosis and is more common in younger people and sportsmen.
  • Hair infection (tinea capitis) is most common among children, often resulting in bald patches with psychosocial consequences. In a recent US survey, tinea capitis was found in 6.6% with ranges from 0% to 19.4%, is more common in deprived areas and black children (with rates up to 41%), suggesting a global prevalence of 200 million cases.

UK-specific burden (figures from Pegorie UK burden of fungal disease J Infection 2017)

The UK population in 2011 was 63,182,000 with 18% aged under 15 and 16% over 65. The following annual burden estimates were calculated:

  • Invasive candidiasis 5142
  • Candida peritonitis complicating chronic ambulatory peritoneal dialysis 88
  • Pneumocystis pneumonia 207-587 cases
  • Invasive aspergillosis (IA), excluding critical care patients 2901-2912
  • IA in critical care patients 387-1345 patients
  • <100 cryptococcal meningitis cases
  • 178,000 (50,000-250,000) allergic bronchopulmonary aspergillosis cases in people with
    asthma, and 873 adults and 278 children with cystic fibrosis
  • Chronic pulmonary aspergillosis is estimated to affect 3600 patients, based on burden estimates post tuberculosis and in sarcoidosis.

 

The Fungal Infection Trust August 2017

For more details (fully referenced), read the complete article: How Common are Fungal Diseases (v12.2)