Two cases of human thelaziasis and brief review of Korean cases

Abstract

The present study was performed to describe 2 cases of human thelaziasis (HT) which occurred in Gyeongsangnam- do and to briefly review the previously reported Korean cases. A 58-year old woman, residing in Hadong-gun, Gyeongsangnam-do, came to Gyeongsang National University Hospital (GNUH) complaining of foreign body sensation and itching of the right eye in March 2000. Total 6 adult nematodes of Thelazia callipaeda (2 males and 4 females) were detected in her right eye. A 80-year old man, residing in Jinju-si, Gyeongsangnam-do, came to GNUH complaining of foreign body sensation, itching, and pain of the right eye in December 2007. A total of 5 worms (4 females and 1 degenerated) were removed from his right eye. We analyzed characteristics of the total 39 Korean HT cases reported to date, including the present 2 cases. Most of the cases (71.8%) occurred in Seoul and Gyeonggi-do before 2000, and 21 cases (53.8%) were males and 18 (46.2%) were females. The prevalence was higher in younger ages below 30 years (48.7%) than 31-60 years (41.0%) and over 61 years (10.3%). The seasonal prevalence showed a higher incidence in autumn (43.6%) than in other seasons. Most of the cases (94.9%) were conjunctival sac infections and only 2 (5.1%) were intraocular cases. The present 2 HT cases are the first reported cases in Gyeongsangnam-do. Some characteristics of Korean HT cases were analyzed.

Keywords: Thelazia callipaeda; case report; review; thelaziasis.

Fig. 1

The right eye of the first case (58-year-old man) infected with Thelazia callipaeda adult worms.

Fig. 2

Light microscopic (LM) (A) and scanning electron microscopic (SEM) views (B-E) of the anterior portion of T. callipaeda male worms. (A) The buccal cavity (BC), muscular esophagus (E), esophageal nerve ring (ENR), and intestine (I) are seen (scale bar=0.1 mm). (B) Anterior portion with the buccal cavity, 2 cephalic papillae (in box) and cuticular folded striations, which were arranged about 375 rows per 1 mm length. (C) Enlarged view of 2 nipple-like cephalic papillae (scale bar=5 µm). (D) A body papilla located at anterior 1/10 in a longitudinal groove (scale bar=5 µm). (E) Enlaged view of a body papilla (scale bar=2.5 µm).

Fig. 3

Middle and posterior portions of T. callipaeda males. (A) SEM view of the middle portion with cuticular striations, which were arranged in about 220 rows per 1 mm length. (B) SEM view of the posterior portion with cuticular striations, which were arranged about 240 rows per 1 mm length. (C) LM view of posterior end with a coiled tail (scale bar=0.1 mm). (D) SEM view of the posterior end with a spicule (S) and 7 pairs of postanal papillae (arrow marks). (E) Enlarged view of a postanal papilla.

Fig. 4

LM (A-D) and SEM views (E-H) of T. callipaeda females. (A) Anterior portion with the scalariform buccal cavity (BC), a long muscular esophagus (E), and a vulva opening (VO) which is located at more anterior portion than the esophago-intestinal junction (arrow) (scale bar=1 mm). (B) The proximal part of the uterus with numerous coiled larvae (scale bar=1 mm). (C) The distal part of the uterus with lots of eggs (scale bar=1 mm). (D) The posterior end of a worm with the rectum (R) and anus (A) (scale bar=1 mm). (E) The anterior portion with folded transverse striations, which were arranged about 250 rows per 1 mm length. (F) The middle portion with transverse striations, which were arranged about 170 rows per 1 mm length. (G) The posterior portion with transverse striations, which were arranged about 375 rows per 1 mm length. (H) The posterior end with encircled striations (scale bar=10 µm).