VIRUSES, bacteria, and protozoa have ravaged the global healthcare industry for centuries. Influenza, herpes simplex, and other viruses have been documented for over 100 years but fungal infections were recognized as medically important in the 1980s. Disease caused by a virus has an impact in all parts of the world weather less developed, developing, and developed countries millions of people have succumbed to viral diseases across the globe.
By lnnocent Njazi
Health experts have responded very well by developing vaccines, developing diagnostic and preventive tools, and building a strong surveillance system. Vaccination completely eradicates smallpox. Hepatitis B, influenza and measles deaths have rapidly fallen over the years. Bacterial infections have profoundly impacted health and enough measures have been taken with great innovations targeting prevention, treatment, and diagnosis of bacterial diseases.
Protozoa have been recognized to threaten humans in different parts of the globe which has resulted in the development of new drugs, vaccines, and diagnostic tools. However, when it comes to fungal infections it is a different scenario. Diseases caused by fungal have been neglected, though they have less impact on health compared to viral and bacterial infections there is no equity in terms of action taken to combat fungal infections.
What are fungal diseases?
Fungi live in the air, water, soil, and plants some live naturally in the body. Just like bacteria, fungi can both be beneficial and detrimental to mankind. Harmful fungi invade the body causing fungal diseases. When people hear of fungi often they think of athelete’s foot, mushroom, or common bathroom mould. However fungal infections can be fatal and kill about 1.5 million people globally every year. Fungal diseases go beyond skin infections they can be systematic infections thus invading our blood, lungs, and others organs. There are an estimated 1.5 million species of which 300 are pathogenic to humans. Very few people know Aspergillus, Candida, Pneumocystis, and Cryptococcus which are serious fungal diseases in humans.
Most infections occur in immunocompromised patients those with HIV, cancer, those who have undergone organ transplants, and patients taking corticosteroids. About 200 spores of aspergillus get into our lungs daily but our immune system fights those fungal infections. However infections in healthy people are on the rise, global warming is also triggering the increase of fungal diseases in humans. A warmer climate changes the distribution of heat-tolerant and vulnerable species by favoring those that are more tolerant to heat. A warmer climate also creates conditions in environment causing fungi to disseminate and bring harm to humans. Unlike bacterial diseases fungal diseases are chronic they kill the host slowly. They are also more recalcitrant to therapy such that most invasive mycoses require treatment courses that last longer.
Impact of fungal diseases
Over 300 million people suffer from fungal-related diseases,1,7 million people die yearly which is equal to tuberculosis deaths and surpass malaria annual deaths. The Global Action Fund For Fungal Infections estimates that more than 1 million eyes go blind due to fungal keratitis. More than 400 000 people are diagnosed with pneumocystis pneumonia annually and perish without access to proper treatment services. Every year about 220 000 news cases of cryptococcal meningitis are detected worldwide, causing 180 000 deaths which are mainly from sub-Saharan Africa. Fungal diseases are most common in low and middle-income. A recent study done in Zimbabwe revealed that approximately 14.9 % of Zimbabwe suffer from fungal infections annually, tinea capitis, cryptococcal meningitis, and pneumocystis pneumonia as common infections. Compared to other countries Zimbabwe seems to be affected more, there is a need to improve surveillance.
Fungal diseases in low and middle countries must be given special attention. The impact of fungal diseases goes beyond human’s consequences they destroy a third of all crops annually. Fungi cause losses in five of the most important crops which are rice, maize, potatoes, wheat, and soybean resulting in economic loss and global poverty. Crops produced in the tropics, such as coffee, cacao, bananas, spices, and mangos, are currently affected by fungal infections, and these crops are not produced in colder climates. Therefore dependence on crops produced in tropical regions aggravated with a lack of biodefense and preparedness might bring economical consequences worldwide
Fungal diseases are not given the attention they must be given, with more deaths than malaria. The disparity of funds directed to combat fungal infections in comparison with viral and bacterial infections is not justified. Even as now antimicrobial resistance is on the rise and many stakeholders are raising awareness, antifungal resistance gets very little coverage. Due to a lack of funding, there is a weak surveillance system to monitor fungal disease incidence and antifungal drug resistance. As for now WHO has no funded program which targets specifically fungal diseases. Less than 20 countries
have fungal references diagnostic laboratories and less than 10 have national surveillance programs for fungal infections. There is a lack of diagnostic tools worldwide and a few that exist are not available in third world countries.
Though many fungal diseases are neglected in healthcare some fit the World Health Organization definition of neglected tropical diseases. For a disease to be recognized as a neglected tropical disease it has to meet these four criteria:
- Disproportionately affect populations living in poverty, causing important morbidity and mortality
- Affect populations living in tropical and sub-tropical areas
- Be immediately amenable to broad control, elimination, or eradication
- Be relatively neglected by research
Of all fungal diseases, mycetoma and chromoblastomycosis are classified as Neglected Tropical Disease by WHO.
Due to the neglect of fungal diseases some cases of tuberculosis are been misdiagnosed with fungal lung infections. Pulmonary fungal infections have similar clinical and radiological characteristics to tuberculosis which may easily be misdiagnosed as tuberculosis. Chronic pulmonary blastomycosis is often misdiagnosed and treated as tuberculosis. Chronic pulmonary blastomycosis presents with cough, weight loss, masquerading as tuberculosis. Years ago researchers from the University of Manchester discovered that more than a million people worldwide diagnosed with tuberculosis go on to develop pulmonary aspergillosis a fungal infection.
Often pulmonary aspergillosis is not treated because it is mistaken for the recurrence of tuberculosis. Clinical symptoms and X-ray features are similar so medical practitioners misdiagnose and prescribe wrong medication causing deaths. The fungal infection which causes chronic pulmonary aspergillosis progress slowly in the lungs and may lie undetected for years until symptoms start to manifest. By the time symptoms start to manifest it will be too late for treatment as a result 50% of patients are unlikely to survive for more than 5 years. Many patients are been given unnecessary antibiotics for pulmonary aspergillosis which is causing the emergence of drug resistance which is a global health threat today. Scientists from Rutgers University who conducted a study on misdiagnoses of tuberculosis said
“The lack of availability and underuse of nonculture fungal diagnostics results in overprescribing, prescription of unduly long courses of antibacterial agents, and excess empirical use of antifungal agents and leaves many millions of patients with undiagnosed fungal infections,”
What needs to be done
There is a need to improve the diagnosis of fungal diseases and strengthen laboratories capacities in developing countries. Mycologic training must be encouraged and improved for all health care professionals. There is unjustified small funding for research on fungal diseases, other diseases which cause similar mortality receives more funding.Funders must consider funding fungal researches to improve understanding of fungal diseases and anti-fungal drugs resistance this will help to develop new diagnostic and antifungal strategies. At the moment there are no licensed vaccines to prevent fungal diseases, vaccines are a priority in reducing fungal deaths. This is a long-term goal but through support and funding, it can be speeded.
ABOUT THE AUTHOR
lnnocent Njazi is a third year student studying Bachelor Of Science ln Nursing
Science at University Of Zimbabwe , aspiring clinical research scientist: Innocent
can be reached on plnnonjazi@gmail.com or Call/App 0778 44 33 01
Very informative.