Around the age of 25, Sunita (name changed) developed severe ‘sweat rashes’ on her neck in the hot and humid weather of Mumbai. The grains turn black, appearing almost burnt and remain so until the arrival of monsoon. Then, as if miraculously, the dead skin was gone and her neck looked perfect again.
Doctors have told her that she doesn’t need to worry too much about it and that she just tries to keep her neck open and dry. However, Sunita gets embarrassed every time it happens and becomes worried about hiding the rash or explaining it to the shocked and concerned audience. She has been using a popular anti-fungal powder as well as spending time under the air conditioner to control the rash during sweaty summer days. So far this year his neck has been clean.
Sunita’s situation may sound familiar to the increasing number of people suffering from fungal infections in India. The World Health Organization released a priority list of fungal pathogens in 2022, noting that there is a lack of data on fungal diseases and their morbidity. A review in 2024 Lancet Infectious Diseases An estimated 3.8 million people die each year from fungal diseases, which has increased due to public fears about antimicrobial resistance and concerns about how well antifungal drugs work.
However, for this situation, India lacks expertise on the origin and effects of fungal pathogens as well as dedicated institutions for fungal outbreaks, like it does for viral and bacterial infections (such as tuberculosis).
mindset, investment problem
Fungi grow well in warm and humid conditions, making tropical countries more at risk than temperate regions.
“In the western world, especially in temperate conditions, ophthalmologists see one to two cases per year,” said Prashant Garg, executive chairman, LV Prasad Eye Institute (LVPEI), Hyderabad. “The numbers are much higher in tropical countries. We see three to four cases of fungal eye infections every day in our hospital.”
According to an estimate published by scientists from India and Britain open forum infectious disease In 2022, more than 5 crore Indians are likely to suffer from fungal diseases – one of the highest national burdens worldwide. These diseases are generally called mycoses; They affect the eyes, skin, lungs, vagina and brain and cause blood infections. During the COVID-19 pandemic, an opportunistic infection called mucormycosis gained attention. Due to black fungus its prevalence is approximately 80 times more In India compared to economically developed countries.
Despite the burden of fungal diseases in India, physicians are often not equipped to deal with them. Most doctors prescribe antibacterial drugs first. When those don’t work, they try antifungals. This delay allows the fungus to penetrate deeper into the patient’s body and become harder to get rid of.
‘A dying art’
Professor Anuradha Chaudhary, director of the Vallabhbhai Patel Chest Institute at Delhi University, said, “Many cases that test negative Mycobacterium tuberculosis It is still called tuberculosis and is treated with anti-tuberculosis drugs. Our country’s microbiology departments do not test them for common respiratory fungal conditions like aspergillosis or rarely diagnosed histoplasmosis.
“Fungal testing should start at the same time as bacterial testing in the microbiology laboratory,” said Dr Chaudhary.
Fungi are present everywhere. When a person tests positive for a fungal infection, there is sometimes doubt as to whether the fungus came from the patient’s sample or whether it is a contaminant that entered the sample from the testing facility or tester. The most reliable way to confirm fungal infection is to grow it on microbiology culture plates.
“We lightly scrape a sample from the infected area of the eye, place it on different culture media. Some allow the growth of bacteria and some fungi,” said Joveta Joseph, LVPEI head of microbiology. “We sometimes have to wait several days to see if fungus grows where we placed the patient’s sample on the culture plate. If fungus grows elsewhere on the plate, it is due to contamination.”
Identifying the actual pathogen may take longer than confirming the presence of the fungus. Here, the details of fungal spore morphology matter. Fungal spores come in a variety of colors, shapes, and sizes. And microbiologists use fungal handbooks and databases to identify spores.
“It is a dying art,” Dr. Chaudhary said.
“Also, some fungi do not form spores in laboratory cultures. Or the entire process may take up to a month,” Dr. Joseph said. “Very few medical setups invest in this kind of testing. It is costly for the patient and technically difficult for healthcare providers.”
treating animals
These challenges are not limited to human medicine. The chytrid fungus causes an infection called chytridiomycosis, and it is decimating frogs and salamanders in many parts of the world. Chytrids grow on the skin of animals – a vital organ for respiration among these amphibian animals. To make matters worse, it is very difficult to distinguish an infected animal from an uninfected animal in the early stages of infection, when the animal can still be saved.
“Culturing chytrid fungi in the laboratory is almost a makeshift task as they exist in small numbers,” said Karthikeyan Vasudevan, a scientist at the CSIR-Centre for Cellular and Molecular Biology. “Some people add hair to their cultures, some snake skin because keratin helps this fungus grow. But details like how much to add or when to add are not often shared in research papers.”
Of course, more advanced tests are more helpful. They help reduce contamination as well as speed up the reactions needed to identify specific species. For example, a test called MALDI-TOF – short for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry – has an automated technology that can identify proteins on the surfaces of pathogens. It does this by creating a surface protein signature of the sample and comparing it to existing databases of pathogens.
While MALDI-TOF can identify fungi in about 30 minutes, it remains in the dark about new pathogens emerging in tropical countries, and which are not reflected in prevalent fungal databases. MALDI-TOF is also very expensive. The new units could cost more than Rs 1.5 crore; Even refurbished can cost Rs 10 lakh or more.
PCR tests that examine the genetic material of the pathogen, and which were widely used during the COVID-19 pandemic, are one option. But while they worked well for coronavirus, they are not suitable for fungi. This is because fungal cells have rigid cell walls that need to be broken first to extract the fungal DNA. (PCR works by making multiple copies of DNA material, then examining them for species signatures.)
timely diagnosis
Some work is going on here – like BRIC-Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Staff Scientist Rupinder Kaur. However, these laboratory-scale procedures have not yet been standardized for clinical settings. A major challenge when working with patient samples is the low amount of pathogenic material.
“For fungal infection diagnostics to work in clinical settings, laboratory protocols typically require improvements in sample handling, volume, transportation and storage, standardization, speed, and appropriate contamination controls,” said Dr. Kaur. “It is always helpful if lab protocols use at least a small set of complex, diverse clinical samples to optimize concentrations, time periods for mechanical cell lysis using primers, cell wall-digesting enzymes, bead-beaters, etc. for the developed procedures.”
He added that more advanced PCR tests have not been adequately tested for use in fungal contexts.
Timely diagnosis helps physicians decide appropriate next steps, such as selecting the right antifungal drugs to treat a particular infection. That said, the number of antifungal options available is limited. Fungal cells are eukaryotic cells, like our own cells. Therefore, the molecules that kill fungus can also be harmful for us.
To make matters worse, there is rampant self-medication by patients, over-the-counter sales and many antifungal medications have also become less effective. use in horticulture. When fungi are repeatedly exposed to antifungal compounds in the environment, they develop resistance. From his own experience at LVPEI, Dr. Joseph recalled how identifying pathogens has helped him help his physician colleagues know when they can rely on antifungals to work.
limited understanding
candida Infections are among a small group of fungal infections that have received continued research attention. Most fungal biologists in India use fungi as a model system to understand eukaryotic cell processes such as how genes are expressed in cells and how cells divide. But these experiments have been done with baker’s yeast (Saccharomyces cerevisiae) and the results do not always reach clinically relevant conclusions. said that, candida Structurally similar to baker’s yeast, and technical know-how from one species can be translated into another species.
“Fungal cells exist morphologically in two forms – spherical forms called yeast and long filamentous forms called molds,” Dr Garg said. “Many fungal infections in India are caused by pathogens aspergillus And Fusarium“
“We don’t have enough people looking at the biology of filamentous fungi,” Dr. Kaur said. “Together with candida, Basic questions such as how this fungus, which is often found on human skin, suddenly becomes pathogenic are not well understood.
“We need to study the fungus in its native state as well and understand its relationship with its host,” said Dr Vasudevan. He also highlighted the importance of skilled taxonomists who can diligently grow, identify and maintain fungal cultures.
Like the medical community, the wildlife biology community would also benefit from fungal expertise within the country as specimens cannot travel out of the country, limiting access to skilled personnel.
The good news is that researchers in India are working to identify priority fungal pathogens circulating within their borders, including and beyond the species list to be released in 2022 by the World Health Organization. They are also working to map antifungal resistance in pathogens in the environment and develop new therapeutics, such as antimicrobial peptides. Better equipped hospitals are also training others in the medical community to address the fungal infection crisis.
Somdutt Karak is Head of Science Communication at CSIR-CCMB.
