Deadly Brain Infection from Dental Clinic in Tamil Nadu

Eight Lives Lost to Neuromelioidosis

A tragic incident occurred in 2023. Eight people died from a brain infection called neuromelioidosis. They contracted this infection from a dental clinic in Vaniyambadi town, Tamil Nadu. A study published in The Lancet brought this to light.

What Caused the Outbreak?

The outbreak happened due to poor hygiene practices at the dental clinic. A team of doctors from CMC Vellore, ICMR-NIE, and Tamil Nadu Directorate of Public Health discovered this. Surprisingly, no government agency had reported this outbreak.

How Did the Infection Spread?

An unsterile tool, called a periosteal elevator, was used to open a saline bottle. The bottle was then loosely resealed. The clinic reused the saline, which led to the infection. At least 10 people got infected, and sadly, eight of them died. This means the fatality rate was a shocking 80%. Dr. Angel Miraclin Thirugnanakumar, the lead author of the study, confirmed this.

Why Was the Infection So Deadly?

The infection spread rapidly and was deadly. This might be because the bacteria in the saline traveled directly along nerve pathways. This happened when the saline was used to clean the patients’ mouths during procedures. Usually, such infections travel through the bloodstream. Whole genome sequencing showed that the bacteria had a gene that aggressively attacks the brain.

Understanding Neuromelioidosis

Neuromelioidosis is a serious infection. It affects the central nervous system, including the brain and spinal cord. The bacterium Burkholderia pseudomallei causes it. This bacterium is found in contaminated soil and water in tropical and subtropical regions.

Symptoms to Watch Out For

• Fever
• Headache
• Slurred speech
• Visual distortion
• Facial palsy in some cases

Key Findings from the Study

Researchers identified 21 cases of neuromelioidosis between July 2022 and April 2023. Ten of these patients had visited the dental clinic. There were nine deaths in total. The fatality rate among the remaining 11 patients, who did not visit the dental clinic, was 9%. Of the total 21 patients, 17 were in Tirupattur district, two in Ranipet, and one each in Tiruvannamalai and Krishnagiri.

Rapid Death Among Dental Clinic Patients

The patients who died after visiting the dental clinic passed away quickly. It took only 16 days from the start of symptoms to death. It took just nine days from hospitalization to death among patients who went to the clinic. For the one fatality not linked to the dental clinic, it took 56 days from symptom onset to death and 38 days from hospitalization.

Public Health Response

State public health officials said the study would help identify such cases. This will help understand how the disease spreads and initiate containment measures. “We have stopped the spread with corrective measures. It’s also a reminder for healthcare providers to be aware of infection control measures,” said Dr. T S Selvavinayagam, director of public health.

Investigation and Containment

On May 9, 2023, CMC notified an increase in neuromelioidosis cases. Some of these cases were linked to the dental clinic. On May 13, 2023, health officials held a meeting with healthcare facilities and other stakeholders in Tirupattur and neighboring districts. A team of doctors investigated the cluster to describe the clinical and epidemiological characteristics and identify the source of infection.

Challenges in Investigation

Before doctors could visit the dental clinic to pick samples, the clinic was disinfected. The water supply was cut off, and the clinic was closed following public outcry. However, scientists identified B. pseudomallei from the saline bottle sample. There was no contamination in unopened saline bottles. More samples were tested, and whole genome sequencing was done for further verification.

Differences in Symptoms

Analysis showed that head and neck involvement was common in cases not linked to the dental clinic. This included inflammation of a salivary gland, inner lining of cheeks, and swelling of lymph nodes. But those with dental exposure showed rapid progression. They presented with facial cellulitis and soft tissue abscess, probably because the contaminated saline was ingested.