Microbiologists at the University of Karachi responded on Monday to the panic being generated by recent deaths caused by the rare parasite, naegleria fowleri. A seminar on how to avoid contracting the deadly parasite during Ramazan was organised by the department of microbiology.
A panel of clinical microbiologists and immunologists tried to banish misconceptions about the deadly organism. “Naegleria fowleri is a parasite, not a bacteria or virus as being reported in the media,” pointed out Dr Shahana Urooj Kazmi, the president of the Pakistan Society for Microbiology and an ambassador for the American Society for Microbiologists. She said that the biological and chemical mechanisms with which the parasite destroys brain tissue are still unclear. It multiplies in the brain by splitting into two and causes inflammation, severe headaches, neck rigidity and mental confusion. When brain tissues are extensively damaged, coma and death usually follow. This fatal infection, which acts rapidly, is known as ‘primary amoebic meningoencephalitis’ and usually kills the patient within 72 hours after symptoms appear. Prof. Kazmi added that naegleria fowleri is found across the globe in soil and warm water, including pools of hot industrial waste. The parasite has also been isolated from mineral water in Mexico.
Dr Farooq Haseeb highlighted the unusual lifecycle of naegleria and said that it is capable of going through a full life cycle without passing through the parasitic stage. The amoeba can survive in diverse environments, including water and brain tissue.
Patients arriving at hospitals must be given immediate attention as meningitis is a medical emergency, pointed out microbiologists Dr Zaid Pirzada and Dr Adnan Khan. They said that when cerebrospinal fluid tests positive for flagellated amoeba or trophoiztes, the infected person has already reached a lethal phase. Because of this, laboratory diagnostic methods are not helpful and patients should be treated immediately with antibiotics once there is enough reason to believe that the parasite may have invaded the body. Prof. Dr Fasih said that old adage ‘prevention is better than cure’ can help reduce the incidence of infection. “Since the parasite is very rare, there is an extremely limited market for effective drugs or vaccines to combat infection. Therefore, no company has found it viable to invest in creating medicines to battle naeglaria,” he said. It is better to avoid contracting the parasite by maintaining a clean, pathogen free water supply, he said.
Prof. Kazmi concluded the discussion by saying that epidemiological surveys need to be carried out so that the prevalence of protozoan encephalitis cases can be determined and areas with contaminated water can be identified. Awareness also needs to be created among the public about the importance of maintaining high standards of sanitation the supply of water to schools, hotels, residential areas and mosques. She also pointed out that even if the water provided by Karachi Water and Sewerage Board is safe when initially released, it may get contaminated with sewage water because of leaking pipes. This could cause the level of chlorine to dip below the recommended level.
The experts said that boiled, sterilised or filtered water should be used, especially when brushing teeth, gargling, or cleaning the nasal area.
Published in The Express Tribune, July 25th, 2012.