
Objective: A detailed study was done in the patients with hookworm infection found in the duodenum while doing upper gastro intestinal endoscopy in order to classify patients with hookworm infection into five stages based on anaemia and eosinophilia in patients with hookworms found in duodenum while doing endoscopy. Such classification of hookworm infection into 5 stages has not been described so far in the literature and is described here for the first time in the literature. Methods: A study of 1307 patients who had undergone upper gastro-intestinal endoscopy for a period of 5 years and one month from May 2009 to May 2014 was carried out. In all the patients found to have hookworms in duodenum, investigations were done to know about the presence or absence of anaemia and presence or absence of eosinophilia. Results: Out of these 1307 patients, 14 patients found to have hookworms in duodenum while doing upper gastro-intestinal endoscopy were taken into consideration for our study. Out of these14 patients, 5 patients did not have anaemia and 9 patients had anaemia. Out of the 5 patients who had absence of anaemia, one patient also had absence of eosinophilia, but the remaining 4 patients had eosinophilia. Based on the presence or absence of anaemia and presence or absence of eosinophilia, hookworm infection is classified into 5 stages. Absence of anaemia and eosinophilia is the earliest stage or the first stage, absence of anaemia but with eosinophilia is the early stage or the second stage, mild anaemia is the third stage, moderate anaemia is the fourth stage and severe anaemia is the fifth or the late stage of hookworm infection. Conclusion: Such classification of hookworm infection into 5 stages will be extremely useful to the clinicians to stage hookworm infection according to its severity, to diagnose hookworm infection properly and as early as possible especially by using upper gastro intestinal endoscopy and to treat hookworm infection as early as possible.