British Medical Journal
To the Editor

September 5th 1991


Sir, - I would like to give some remarks as to the article of Dr. Seuri about higher incidence of appendectomy in persons having frequent contact with pigs (1).

I have recently had a female patient, 29 years of age, wife of a swineherd, having genital trichomoniasis since delivery 6 years ago. She had clinical exacerbations 3-4 times a year and persistently positive findings in cervical smears. In the initial phase of exacerbations, parasites and trophozoites have been found, while in remissions they have been found in cervical mucus in aflagellary motionless form.

Five months ago, she was sent by a practitioner to gynaecologist because of pains in the lower stomach. Quite normal finding of inner genital organs was established, but surprisingly, microscopic finding of trichomonads in cervical mucus was negative. The patient was sent to a surgeon and the appendectomy was made the same day.

Having been intrigued by spontaneous clearing of cervical mucus, I examined microscopically stained wet films of the squeezed excaudate from amputated inflamed appendix and aflagellary form of trichomonads was detected. As the culture was negative, it was not possible to determine the parasite species. At the gynaecological examination, 3 months after the appendectomy, cervical smear became positive again.

As the main cause of appendicitis has not been recognised since now, various bacteria have been given more or less importance. However, Dr. Seuri’s finding is in positive correlation also with the very frequent Trichomonas suis infection of the whole digestive tract of pigs, mostly in cecum. On the other hand, Trichomonas Hominis (Intestinalis) infection of the human guts is not rare, mostly in cecum and appendix.

Trichomonads are obligatory immunogenic agents, even if they are localised intraluminally, and all 3 human species have crossed immunity. Longstanding and polystrain sensitization of man by Trichomonas suis antigens can exhaust immune apparatus, well known event in parasitoses. In such cases, pre-existing appendix trichomoniasis of man, especially associated with (micro) trauma of mucosa, can widen epithelia lesion, or at least prevent re-epithelisation, thus enabling deeper invasion of the bacteria. To my knowledge, the only study about trichomonas infection of inflamed appendix, using direct microscopic examination of cuted appendix, reports an 8% incidence (2).

Rare incidence of appendectomy in woman, in Dr. Seuri’s report, could be attributed to frequent trichomoniasis of genital tract in women, which elicits protective immunity against extragenital trichomonas infection. Frequent challenges with pig trichomonas antigen can weaken immune resistance to pre-existing subclinical Trichomonas hominis infection of appendix by man. The well known beneficial effect of preoperative metronidazole use by appendectomy can be at least partly ascribed to neglected gut trichomoniasis. So, Dr. Seuri’s finding of the positive correlation between appendectomy and frequent contacts with pigs, casts a new light on possible involvement of the Trichomonas species in pathogenesis of Appendicitis.

Sukrija Krvavac
Public Health Centre Stari Grad
University and Medical Centre
71000 Sarajevo, Yugoslavia

1.    Seuri M. Risk of appendectomy in occupations entailing contacts with pigs. BMJ 1991, 303:345-6.
2.    Jašović M. The role of parasites in ethiology of appendicopathy. Acta Chir Iugosl 1961, 8(9): 122-7.