• Epidemiologists observe the absence of a risk of listeriosis outbreak but urge the public to maintain vigilance of symptoms and to seek medical attention in the event they exhibit such while calling for awareness on TB testing

Although there is a fear in the society that the disease known as listeriosis could be spreading fast, verified information suggests that there is no risk of a listeriosis outbreak occurring in the country. Thus far, Sri Lanka has reported only one or two cases. Various tests and probes conducted following those incidents have not revealed any other cases of listeriosis.

Noting this, several medical experts of the Health Ministry’s Epidemiology Unit added that despite the lack of reasons to suggest a listeriosis risk in the country, the public should be vigilant about symptoms and not hesitate to seek medical assistance when in doubt. They made these remarks during a press briefing held this week to discuss the state of listeriosis and to mark World Tuberculosis (TB) Day. The event was also attended by chest and respiratory diseases’ experts.

The listeriosis scare

Medical experts explained that following the first case of listeriosis being reported from a person who had visited the Adam’s Peak and had tested positive for the disease, the health authorities had conducted a number of tests on more people who visited the Adam’s Peak and also on food and water samples obtained from that environment. However, thus far, no further signs of the existence of listeriosis have been identified. Although there were certain individuals who showed symptoms of listeriosis and some are receiving treatments for the same, others have recovered and been discharged. Yet, none of these individuals had however tested positive for the disease.

The Epidemiology Unit’s Chief Epidemiologist Dr. Samitha Ginige shed some light on listeriosis, noting that this disease, which is caused by a type of bacteria, is not a totally foreign disease. “This is a food borne disease, which means that this disease transmits through contaminated food. There is a high risk of this disease transmitting through dairy-based food items. Many who have contracted this disease do not show symptoms. However, in rare cases, complications may occur. Among those who are likely to experience serious complications are those who have certain deficiencies in their immune system such as pregnant women, those living with cancer, kidney diseases and various chronic illnesses, and those who are on medication for immune system related issues. In rare cases, these complications may even result in death.”

According to Dr. Ginige, there are no reports of this disease reaching a large-scale epidemic level anywhere in the world, while the available reports are about isolated listeriosis cases. Globally, listeriosis cases remain at a low level, i.e. 0.1 to 10 cases per one million people. 

“This is not a disease that could reach an epidemic level, and therefore, there is no need to have irrational fears. What is more, isolated listeriosis cases being reported is not an unusual situation,” he said, adding that tests conducted on water and food samples, which were obtained from places where the confirmed and suspected listeriosis patients were present during their Adam’s Peak trip, have not proven the existence of the listeriosis bacteria.

With regard to suspected cases, he added that while it is a positive development that many who visited Adam's Peak and are experiencing certain symptoms such as vomiting and diarrhoea have sought medical assistance, none of them have tested positive for listeriosis as per various medical tests. Noting that although certain symptoms of listeriosis, such as vomiting, fever, body aches, and diarrhoea are symptoms of many other diseases, Dr. Ginige stressed that the health authorities remain vigilant about the present situation.

His message to the establishments that provide food and those who obtain food from those places was that this is not just a matter about listeriosis, but that food hygiene is a quality that should be practised regardless. While the Health Ministry has a responsibility to pay attention to it, he added that it is a matter that every person should be vigilant about and that it is good that food hygiene has received more attention.

Tuberculosis

Meanwhile, the experts discussed the state of tuberculosis in the country, while marking the World Tuberculosis Day which falls today (24). Sri Lanka records around 8,000-9,000 tuberculosis patients a year, while the mortality rate among identified tuberculosis patients is around 7%, which is equivalent to 500-600. Through raising awareness, it is possible to get people to seek medical assistance without delay, provide treatments for those in need, and to prevent the spread of the disease. 

At present, there are more than 160 centres tasked with performing tuberculosis tests across the Island. Any person who feels that they might have contracted tuberculosis could obtain services from these centres with or without a doctor’s prescription for a test. There are four culture laboratories in Kandy, Galle, Ratnapura, and Jaffna. The National Tuberculosis Reference Laboratory, which also provides these services, is situated in Welisara. In addition, there are chest clinics that provide these services and also treatments. While most treatments are provided as out-patient services, depending on the necessity, a small number of persons are treated through in-patient services. All these services are provided free of charge.

The Health Ministry’s National Programme for Tuberculosis and Chest Diseases Control’s Deputy Director Dr. Nirupa Pallewatte noted that tuberculosis is a disease that could be cured if proper treatments were obtained at the right time and could be successfully prevented through prevention measures. Emphasising that there is a fear in the society towards tuberculosis patients, she added that through awareness, it is possible to alleviate this fear and encourage more people to seek medical treatments. 

She added: “Sri Lanka aims to eradicate tuberculosis by 2035. At present, around 40 per 100,000 persons test positive for tuberculosis. However, by 2035, we expect to reduce it to 10 per 100,000 persons. At the same time, we expect to bring down the mortality rate of tuberculosis patients, which is currently at around 500 per year, to 30 or less per year.”

Moreover, the National Programme for Tuberculosis Control and Chest Diseases’ Community Physician Dr. Mizaya Cader explained that although until 2019, the most number of deaths caused by an infectious disease in the world was due to tuberculosis, after 2019, that situation changed due to the emergence of the Covid-19 pandemic. In 2021, the number of estimated tuberculosis patients in the world was around 10.6 million, while around 1.6 million persons died due to tuberculosis. 

“The East Asian region accounts for 43% of worldwide tuberculosis patients, although its population constitutes merely 25% of the world population. Sri Lanka does not have a big tuberculosis issue compared to other countries. In 2021, 8,342 tuberculosis patients were reported in Sri Lanka. When we look at data from 2016, it shows that the usual number of tuberculosis patients that are reported a year is between 8,000 and 9,000. In 2020 and 2021, or in the Covid-19 pandemic era, there was a significant decrease in the number of such patients; while 7,700 patients were reported in 2020, and around 6,700 patients were reported in 2021. However, in 2022, the number of patients increased to the level that existed in 2019. We believe that it was not entirely a result of tuberculosis. Since tuberculosis and Covid-19 have certain common symptoms, such as coughing, the public’s treatment seeking behaviours changed in 2020 and 2021, and they feared to come forward to seek medical assistance.” 

With regard to claims about tuberculosis patients being in the society without being reported, Dr. Cader added: “There were claims that about 4,000 tuberculosis patients were roaming free. That is based on the World Health Organisation’s estimated number of patients for each country. Therefore, technically, around 63 patients should be reported per 100,000 persons. However, in 2022, we will have detected only 36.6 patients per 100,000 persons. In other words, although we were supposed to detect some 14,000 patients, we have detected only around 8,000 patients in 2022. There is a difference of around 5,800 patients between the expected and actual number of patients, and they could be freely roaming among us.” She added that in this context, in order to detect all tuberculosis patients, the support of the society in general and of all parties is necessary. The highest number of patients, i.e. 46% of all patients reported in the country, is reported in the Western Province, while 26% of all patients are reported in the Colombo District. A total of 50% of patients reported in the Colombo District, i.e. more than 1,000 patients, are from the Colombo Municipal Council area. This is a massive issue, especially since the high population density in the area, according to Dr. Cader.

“In Sri Lanka, the ratio between male and female tuberculosis patients is one to two. Data shows that cases among children below the age of 15 years are very less. Only around 187 cases have been reported from that group, which is around 2.2% of all patients as per 2022 data. However, those between 15 and 54 years report more tuberculosis cases than those of other age groups. At the same time, those in the 55-64 years age group and are older than 64 years, show more cases. One of the reasons for that situation is that tuberculosis, in many cases, is related to non-communicable diseases such as diabetics and kidney diseases which many older people live with.”