After reading the article by Pizza et al. on endoscopic diagnosis of hookworms, we thought it would be important to mention some issues related to this case of hookworms diagnosed in a patient with anemia. ¹ Endoscopy found a mobile parasite in the duodenum and multiple worms in the ascending colon and in the cecum. The authors assumed that findings from esophagogastroduodenoscopy and colonoscopy were compatible with hookworms.

However, Necator americanus helminths and Ancylostoma duodenale helminths (commonly grouped together as hookworms) reside in the upper portions of the small intestine while helminths of the genus Trichuris trichiura (commonly known as whipworm) reside in the cecum and the ascending colon. ² If the usual habitat sites of these germs and macroscopic aspects clearly evidenced in the two photographs included with the article are taken into account, the etiological agents identified by endoscopy and colonoscopy in the case described in this article are from a different species.

The photographs show a worm in the cecum whose appearance is distinct from the worm detected in upper endoscopy: it has a rolled end that resembles the macroscopic characteristics of a male T. trichiura. ^2,3 T. trichiura can produce clinical symptoms such as severe anemia and even dysentery which are similar to those of hookworm infections. ^3,4

Similarly, intestinal polyparasitism should be considered in patients who come from vulnerable populations such as rural areas and developing countries. Studies in Colombia have established prevalences of polyparasitism of 84% and 89.2% of the patients analyzed in regions of the Amazon and the Atlantic Coast. ^5,6 The combination of hookworms and T. trichiura had a prevalence of 16.7%. ⁵

Diagnosis of intestinal helminthiasis can be complex. It begins with detection of eggs or adult parasites in fecal matter as indicated in the review of the topic. ⁷ However, the authors do not report performing any stool tests making other techniques for establishing the taxonomy of these worms, and thereby providing optimal therapy, a requirement.

One such technique is extraction of the worm with biopsy forceps after it has been identified during endoscopy. ⁷ This procedure is not only diagnostic but is also therapeutic since T. trichiura is sometimes embedded in the mucosa and cannot be expelled after anthelmintic treatment. ^8,9

The article also indicated that the patient was treated with pyrantel pamoate, but the most suitable treatments for polyparasitism are based on repeated doses of benzimidazoles such as albendazole, mebendazole and ivermectin. Among these drugs, albendazole is the most effective for management of both immature and adult forms of hookworms and whipworms. ^10,11

Pyrantel pamoate is generally left as an alternative therapy for N. americanus or A. duodenale infections but is not effective for treatment of trichuriasis ^2,3