Hookworm infestation is not an uncommon cause of obscure occult and overt gastrointestinal bleeding in an endemic area: A study using capsule endoscopy

Capsule endoscopy for obscure gastrointestinal bleed in the tropics: A single-center experience on 350 patients

BACKGROUND

Obscure gastrointestinal bleed (OGIB), now called small bowel bleed (SBB), comprises 5% to 10% of all gastrointestinal (GI) bleed episodes and capsule endoscopy (CE) is a tool for its evaluation. Studies on CE in a large sample of SBB patients from the tropics are limited.

METHODS

We did a retrospective analysis of a prospectively maintained database of patients with SBB undergoing CE using PillCam or MiroCam CE.

RESULTS

Of 350 patients (age 52.4 ± 17.4 years; 248 [70.9%] male) undergoing CE, 243 (69.4%) and 107 (30.6%) had overt and occult SBB, respectively. CE detected lesions in 244 (69.7%) patients (single lesion in 172 [49.1%]; multiple in 72 [20.6%]). The single lesions included vascular malformations (52, 14.9%), ulcer/erosion (47, 13.4%), tumor (24, 6.9%), hookworm (19, 5.4%), stricture (15, 4.3%), hemobilia (1, 0.3%) and blood without identifiable lesion (9, 2.6%). Of 72 with multiple lesions, ulcer with stricture was the commonest finding (n = 43, 12.3%). No abnormality was detected in 106 (30.3%) patients. The frequency of lesion detection was comparable among patients with overt and occult SBB (173/243, 71.2% vs. 71/107, 66.3%, respectively; p = 0.4). Younger patients (0 to 39 years) more often had multiple lesions on CE than the older (≥ 40 years) ones (26/76, 34.2% vs. 46/228, 20.2%, respectively; p = 0.001).

CONCLUSION

CE has a high diagnostic yield in SBB in the tropics, regardless of the type of bleed or of CE brand and the duration of recording. Multiple lesions associated with SBB are commoner among younger (< 40 years) patients.

Capsule endoscopy for small bowel bleed: Current update

Small intestine, hitherto an obscure area for endoscopists before 2000, is now easily evaluated non-invasively using capsule endoscopy and invasively by device-assisted enteroscopies. Major advances in understanding the causes and management of small bowel diseases have been in obscure gastrointestinal (GI) bleed, currently re-named as small bowel bleed, after the discovery of capsule endoscopy. The current article is a narrative review of the technology of capsule endoscopy, its advantages and limitations, future perspective and Indian studies on its utility in patients with small bowel bleed. Till date, eight large series reporting 2319 patients with obscure GI bleed (1554 overt and 765 occult) undergoing capsule endoscopy have been reported from India. Overall yield of capsule endoscopy to detect lesions in these studies varied from 43.5% to 90%. The major causes detected in various studies for small bowel bleed include vascular malformation, portal hypertensive enteropathy, ulcer, stricture, tumor, polyps, etc. Hookworm can cause both occult as well as overt small bowel bleed as shown mainly from India. Capsule endoscopy has also been quite safe in patients with small bowel bleed as despite 0.6% to 15% retention of imaging capsule in Indian studies, development of clinically evident small bowel obstruction has rarely been reported. The major limitations of capsule endoscopy include lack of maneuvrability and therapeutic capability. Research is in progress to overcome some of the limitations of the current capsule endoscopy system. It is concluded that discovery of capsule endoscopy has brought a new paradigm in GI endoscopy and explored a hitherto unexplored area of GI tract, i.e. small bowel that continued to be a black box for the endoscopists.

Soil-Transmitted Helminths and Anaemia: A Neglected Association Outside the Tropics

Anaemia is an important cause of morbidity and mortality globally. Among infectious agents responsible for anaemia, helminthic infections are often neglected, particularly in non-endemic countries. However, they should not be neglected in this setting, as international travel and migration are on the rise. In this narrative review, we aimed to describe soil-transmitted helminths as a cause of or contributing factor to anaemia, focusing on hookworms (Necator americanus and Ancylostoma duodenale), the whipworm (Trichuris trichiura), the roundworm (Ascaris lumbricoides), and the threadworm (Strongyloides stercoralis). A general review on the epidemiology, lifecycle, and clinical spectrum of anaemia is proposed, with a special focus on helminthic infections’ association with anaemia as well as the diagnostic approach, which are both particularly important in non-endemic settings.

Soil-transmitted helminth infections

More than a quarter of the world's population is at risk of infection with the soil-transmitted helminths Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), Trichuris trichiura, and Strongyloides stercoralis. Infected children and adults present with a range of medical and surgical conditions, and clinicians should consider the possibility of infection in individuals living in, or returning from, endemic regions. Although safe and effective drugs are donated free to endemic countries, only half of at-risk children received treatment in 2016. This Seminar describes the epidemiology, lifecycles, pathophysiology, clinical diagnosis, management, and public health control of soil-transmitted helminths. Previous work has questioned the effect of population-level deworming; however, it remains beyond doubt that treatment reduces the severe consequences of soil-transmitted helminthiasis. We highlight the need for refined diagnostic tools and effective control options to scale up public health interventions and improve clinical detection and management of these infections.

Gastrointestinal bleeding in the tropics: Look for the hookworm

Hookworms are recognised as a cause of iron-deficiency anaemia in endemic areas. They are, however, often not considered in the differential diagnosis of overt gastrointestinal bleeding. We report the endoscopic diagnosis of hookworms as the cause of gastrointestinal bleeding in three patients, two of whom had frank haemorrhage with one presenting in hypovolemic shock. Hookworm infestation is an important treatable cause of gastrointestinal bleeding in tropical countries.