Malaria Mutation Makes Plasmodium falciparum Invisible in Rapid Test, Contributes to 80% False Negative Test Rates

Rapid diagnostics tests have helped control the spread of malaria. However, it seemed that it's not as effective as a certain mutation appears invisible in regular rapid tests.

Malaria Mutation in Rapid Diagnostic Tests

Millions of cases have been diagnosed using the comparatively cheap test strips in minutes, speeding up access to life-saving care. Thanks to the significant improvement in surveillance in remote, harder-to-reach places, the impact of this mosquito-borne illness, which kills over 500,000 people annually worldwide, has also been sharply perceived by public health specialists.

Many nations are experiencing a rise in false-negative test rates -- up to 80% at some hospitals -- due to mutations that make Plasmodium falciparum undetectable to the current gold-standard fast test. Scientists fear the mutations may be spreading unreported, leading to hundreds of thousands of instances of this fatal disease going undiagnosed and postponing treatment, even though the prevalence of the mutations is rarely that high. Global efforts to eradicate the mutations could be severely hampered if new tests aren't developed.

"This is a huge concern, right up there with drug and insecticide resistance," says Jane Carlton, a biologist and director of Johns Hopkins Malaria Research Institute. "That's because it looks like it's spreading."

Scientists first discovered these mutations in 2010 after examining blood samples from patients in Peru. Under a microscope, malaria parasites were visible in the samples, but the patients' quick test results came back negative.

Histidine-rich proteins 2 and 3 of P. falciparum, which are typically accurate markers of infection, are what the majority of malaria fast tests look for. However, the researchers discovered that parts of the pfhrp2 and pfhrp3 genes, which code for the proteins, had been removed from malaria parasites isolated from these Peruvian samples. These make the parasites successfully hidden from commonly used rapid tests.

Health Officials Fear About New Malaria Strain

Health workers in Bangladesh have been giving patients artemisinin to treat malaria because it is effective. Dr. Ching Swe Phru, who's devoted his life to treating patients with malaria in Bangladesh, described the drug as "marvelous" and "perfect."

However, Dr. Phru advises the residents to stay vigilant and acknowledges that the artemisinin-resistant strain is terrifying. The parasites have an innate propensity to resist the lethal medication. He added that malaria has "a certain history of coming back."

For thousands of years, the malarial parasite has plagued humanity. Kasturi Haldar, a microbiologist at the University of Notre Dame who studies the malarial parasite, claims that because of the profound effect malaria has had on our blood, we have been able to evolve natural defenses.

Even so, despite decades of efforts to control the disease, malaria still kills over 600,000 people annually, mainly in Africa. The disease is becoming more widespread due to changes in our environment, allowing mosquitoes that spread it to dwell in formerly uninhabitable areas like the higher altitudes of Ethiopia, Colombia, and some regions of Asia.

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