Worm infestations are among the most common parasitic infections in the world, with a disproportionate burden of infection in resource-limited settings like the Philippines. Despite our recent upgrade to upper-middle-income country status, about half of school-age children in our country are infected with worms. In some areas, the prevalence of worm infection has been found to be as high as 95 percent. The most common types of worms seen are Ascaris, whipworm, and pinworm.

Children with heavy worm infestations can become malnourished and risk becoming stunted, which is associated with lower intelligence and poor school performance. Routine deworming in children decreases the risk of stunting and malnutrition and has a positive impact on the proper development of the brain.

Millions of school kids undergo deworming every year as recommended by the World Health Organization. The Department of Health, in partnership with the Department of Education, has been conducting mass deworming of school children through schoolteachers since 1999, with significant progress in decreasing worm burden in areas with good coverage.

Routine deworming is considered safe and effective as a public health intervention. Unfortunately, misinformation and panic have contributed to decreased coverage in some areas over the years.

The tragic death of a Grade 4 pupil following a routine deworming activity has spooked a lot of people and needs a close investigation. Early news reports are stating that septic shock was the cause of death. An alleged screenshot of the death certificate, highlighting the cause of death, also states the presence of a central nervous system infection. Whether the deworming activity contributed to the current incident or was just coincidental needs to be resolved through scientific investigation, including a properly conducted autopsy.

The medications used for mass deworming programs in the Philippines are albendazole and mebendazole. Albendazole and mebendazole are some of the safest medications around and are given as a single dose to children from one to 18 years old twice a year and are very well-tolerated. These drugs can occasionally cause nausea and mild stomach pain in some recipients, but severe adverse effects are very rare.

There is no mechanism through which albendazole or mebendazole can directly cause septic shock or central nervous system infection. Septic shock is caused by an uncontrolled infection that spreads and causes the blood pressure to drop and the organs to fail. A central nervous system infection can lead to septic shock, but would not be caused by routine administration of anti-parasitic medications.

So, what could have happened? As an infectious diseases doctor and a parasitologist, I can think of three possible scenarios, in decreasing order of likelihood, that may explain the situation. There is not much verifiable medical information available on the case, and so we should wait for the results of the investigation before making conclusions.

If the deceased child is confirmed to have had a central nervous system infection, such as meningitis or encephalitis that was incubating at the time of the deworming, then that infection alone can kill him. The deworming may not have had anything to do with his demise and was just coincidental.

Meningitis is the inflammation of the meninges, which are the membranes wrapped around the brain for protection. Meningitis is usually caused by an infection, most commonly by bacteria, but can also be caused by viruses, fungi, or tuberculosis. Meningitis symptoms include a stiff neck, severe headache, vomiting, and high fever. It can progress quickly and cause death in a very short amount of time.

Encephalitis or inflammation of the brain itself is usually caused by viruses. It is characterized by fever, decreased consciousness, and seizures, and also leads to death quickly. Both infections can progress rapidly to septic shock and death.

In this scenario, it would have been difficult to predict the death, especially if the child was not yet having any symptoms at the time of the deworming. If the child was symptomatic, he/she should not have been given the medication and should have been referred to a health facility ASAP.

If the child had some sort of allergic reaction to the drug, then it could have made a preexisting CNS infection worse. This is very rare because routine deworming medications such as albendazole and mebendazole rarely cause severe reactions. Ivermectin, which is used to treat some kinds of worms, can be quite toxic, but it is not routinely used in deworming programs in the Philippines.

In rare instances of very heavy worm burden, especially if the child is infected with the worm Strongyloides stercoralis, deworming can cause the worms to migrate into the bloodstream, dragging bacteria from the intestines into the bloodstream and causing sepsis.

These worms can also go into the brain and cause a central nervous system infection. This is even rarer than a bad reaction to the medication and should be apparent on a properly done autopsy.

I have also seen this scenario among very immunocompromised people, such as those with HIV or those treated with chemotherapy or other immunosuppressive drugs. People are usually screened for these conditions before being given deworming medications.

There are other possible causes, including improper administration or poor medication quality, but there is no evidence of these being the case. Whatever the reason, the death of a child should always prompt a proper investigation, especially if it happened during a public health exercise.

However, we should resist the temptation to suspend deworming programs without proper evidence and basis because these programs benefit millions of people every year. Social media hype and headline-grabbing reporting have already sidetracked the Department of Health and the Department of Education. We must be careful not to contribute to this noise, and to examine facts as they arise, and continue to support public health interventions proven to save lives.