Increased number of Typhoid cases in Sri Lanka – 2024 

Typhoid fever is a potentially severe life-threatening bacteraemic illnesses caused by the bacteria Salmonella Typhi. Estimated 11–21 million cases of typhoid fever occur worldwide each year causing an estimated 135,000–230,000 deaths. Typhoid fever is a notifiable disease in Sri Lanka and is an endemic disease with epidemic potential.
Typhoid fever is acquired through consumption of water or food contaminated by faeces with the bacteria. Insufficient sanitation and improper hygienic practices predispose to spread of the disease.

 

Observing increased number of cases

There were increased number of laboratory confirmed cases of Salmonella infection reported from microbiology laboratories during March 2024. Several expeditious steps were undertaken by the Sri Lanka College of microbiologists (SLCM) as a part of outbreak investigation activities.

Immediate Actions taken by the SLCM

• Since there was a possibility of an outbreak email notifications were sent to all the members of the SLCM.
• A Google form was created to collect data on positive Salmonella cultures from all the microbiology laboratories and circulated among the members of SLCM.
• Typhoid fever surge investigation committee was appointed within the college to bring about immediate action plan and for decision making.
• SLCM initiated the discussions on the gravity of the problem with the presidents of Sri Lanka Medical Association, Ceylon College of Physicians, Sri Lanka College of Internal Medicine and Sri Lanka College of paediatricians.
• The higher officials of the ministry of health were promptly updated on the surge of Typhoid cases and national level preventive measures were proposed such as public awareness, strengthening hygienic practices of food handlers, establishing a rapid over the phone notification system from medical officers of health etc.
• SLCM initiated a discussion with the Sri Lanka Epidemiology unit and it was noted that the cases reported via the national notification system were less than laboratory confirmed cases. After a discussion they were given the access to the real time data of the laboratory confirmed cases through the Google sheet.
• This enabled them to carry out epidemiological investigations quickly bypassing the possible delays in notification via the hospitals and primary health care system thus enhancing the preventive measures.
• Via the Google form data, the areas from which the majority of cases were reported, the population affected, the clinical features related to the current outbreak and antibiotic sensitivity pattern were identified. The updated information was shared with the SLCM membership, ministry of health and other professional colleges regularly.
• At the same time an educational programme, expert panel discussion on “Typhoid Fever: Don’t Miss it” was conducted by SLCM collaborated with Sri Lanka Medical Association, Ceylon College of Physicians, Sri Lanka College of Pediatricians, and Sri Lanka College of Internal Medicine,  in the beginning of April to convey the message to a wider audience.
• During the expert panel discussion which included more than 100 participants from different clinical specialties from all over the country the atypical clinical features of the current outbreak were discussed. Further the empirical antibiotic therapy was agreed to be third generation cephalosporins based on the sensitivity patterns and decided to exclude ciprofloxacin as majority of the isolates was resistant to it. This was helpful to alert the physicians at the beginning of the outbreak.
• The isolates were sent to the national reference laboratory at Medical Research Institute for serotyping and they were vigilant on reception of the isolates from peripheral hospital laboratories in order to intensify early reception, serotyping of the Salmonella isolates and rapid dissemination of results.

Confirmation of the outbreak

According to the weekly epidemiological reports there were 88,119 and 94 total cases in 2021 2022 and 2023 respectively. From the beginning of the year up to the first week of April there were 28, 45 and 18 cases in 2021, 2022 and 2023 respectively.

Once the collected data was analyzed it was confirmed that there were increased number of cases, identified as Salmonella Typhi. There were 36 laboratory confirmed cases from mid-February to end of March.

By the mid June there were 49 laboratory confirmed cases. There were 48 blood culture isolates and one stool culture isolate.  29 (60%) of them were females and 20 (40%) were males.

Majority 17 out of 49 (34.7%) affected were children followed by young/ working (21-40 year age group) population (16/49- 32.6%).

Majority cases were from Western province, 21 cases were from Colombo district, 10 from Kalutara and 5 from Gampaha. There were also cases from Kandy, Galle and Kegalle.

Interestingly 19 patients out of 49 were reported from private hospital laboratories.

All the isolates were sensitive to third generation cephalosporin. Majority were either resistant or intermediately sensitive to ciprofloxacin. The commonest presenting symptoms was fever followed by diarrhoea and abdominal pain when this surge of cases were concerned.