Serological Follow-up of Human Cystic Echinococcosis in the Thrace Region, Turkey

Background: Parasites of the genus Echinococcus are common worldwide and are important cestodes that cause serious infections in humans and animals. This retrospective study evaluated the indirect hemagglutination (IHA) test results of serum samples obtained from patients with a pre-diagnosis of cystic echinococcosis (CE) within ten years. In addition, the role of the IHA test results of the patients in the follow-up of the treatment and determining possible recurrences was investigated. 
Methods: The IHA test results of 2426 serum samples of patients with a pre-diagnosed CE admitted to Trakya University Health Center for Medical Research and Practice in Edirne, Turkey, between January 2011 and December 2020 were evaluated retrospectively. The data of 53 patients with CE who had medical treatment and/or postoperative follow-up serological records were evaluated. 
Results: Of 2426 IHA tests, 376 (15.5%) were seropositive, and 2050 (84.5%) were seronegative. It was determined that 376 serum samples detected as positive belonged to 207 patients with CE. Of 207 CE patients, 109 (52.7%) were female and 98 (47.3%) were male. The most common organ involvement was the liver in 186 (89.9%) cases. Of 53 patients, 16 were considered relapse cases. The median follow-up period for 16 recurrent cases was 31.8 (1-77) months. Our results showed a statistically significant correlation between long-term serological follow-up and recurrence detection (P=0.034). 
Conclusion: Long-term serological follow-up after treatment is considered useful in determining possible recurrent cases. CE is an important public health problem for endemic regions, including our country, and we think our study results will contribute to the status and follow-up of the disease.