Tjiang W, Ooi SL Amy, See KS Kris
Abstract
Background : Hookworm infection is a relatively common cause of anemia in endemic areas, especially in poor, rural areas in the tropics and subtropics. Ancylostoma duodenale and Necator americanus are the major species of hookworms that infect humans. We present such a case of a patient with hookworm infection, presented with gastrointestinal symptoms and sign of severe iron deficiency anemia.
Case Presentation : We report a case of a 43-year-old male farmer who presented with generalized weakness, fatigue, reduced exercise capacity, intermittent diarrhea without blood and mucus, and lost 4 kg of weight. He had pallor, undernourished, with pansistolic murmur and koilonychias in both fingernails and toenails. Investigations showed severe iron deficiency anemia with hypereosinophilia. Stool for ova examination found hookworm eggs. A diagnosis of hookworm infections was made and patient was treated with mebendazole, supportive measures for anemia and his physical condition much improved.
Conclusions : Hookworm infection is a treatable disease. In case of gastrointestinal symptoms, sign of iron deficiency anemia and hypereosinophilia, the possibility of hookworm infections must be considered particularly in endemic areas. A definitive diagnosis of hookworm infection depends on discovery of eggs in the stool. Benzimidazole anthelmintic drugs such as mebendazole and albendazole are commonly used drugs for treatment.
Keywords : Hookworm infection, Iron deficiency anemia, Hypereosinophilia, Mebendazole
Background
Hookworm infection is a relatively common cause of anemia in endemic areas, especially in poor, rural areas in the tropics and subtropics. Ancylostoma duodenale and Necator americanus are the major species of hookworms that infect humans. The impact of hookworm infection on iron stores depends on the intensity of infection as well as the amount of iron consumed in the diet. Iron deficiency anemia, was reflected by low hemoglobin, MCV, MCH, depleted iron store and microcytic hypochromic erythrocytes in peripheral blood film. An increase in the peripheral blood eosinophils has been recognized as a characteristic feature of helminth infection. Eosinophilia can be detected in 30% to 60% of cases.
Patient presenting with gastrointestinal symptoms, sign of iron deficiency anemia and hypereosinophilia, must alert physician to the possibility of hookworm infections.
This case report highlights that a high degree of clinical suspicion, followed by prompt diagnosis, treatment and prevention, resulted in an excellent outcome to patient and his family member.
Case Presentation
A 43-year-old male farmer presented to hospital with generalized weakness, dizziness, and easily fatigue for 6 months duration. During this period, his symptoms was getting worse, with shortness of breath particularly with exercise, loss of appetite, intermittent diarrhea without blood and mucus, and lost 4 kg of weight (46 kg to 42 kg). His past medical history was included helminthiasis more than 10 years ago which he claimed he was prescribed mebendazole and subsequent 6 monthly prophylaxis treatments for few years. He was a farmer for more than 20 years, and he used to eat with bare hands, and walk bare foot at his home yard. No history of blood transfusion, or taking any other medications.
On examination, he was pallor, undernourished, but non icteric. His blood pressure 110/50 mmHg. He had cardiomegaly with pansistolic murmur grade 2/6. His respiratory system and abdominal examination unremarkable. His nails were brittle, ridged, and spoon-shaped (koilonychia) in both fingernails and toenails. Per rectal examination unremarkable.
Initial blood test revealed anemia with hemoglobin of 4.8 g/dl, MCV 63,1 , MCH 18,0, leucocyte 10,300/µl with eosinophilia 12.2 % (reference range 0.1-6.0 %), and increased platelet count of 698x103/µl. Patient was then admitted and subsequent investigation were as follow : retic count 0.6%, iron status Fe 2 μg/dl , TIBC 394 μg/dl , saturation 1 % , ferritin 9,00 ng/ml. Renal function and liver enzyme was normal. He had low serum albumin level 2,72 g/dl. Peripheral blood film revealed profound microcytic hypochromic erythrocytes with eritropoetic responses, infection process and sensitivity reaction. Stool for ova examination found hookworm eggs.
The patient was given packed red cells transfusion (total 3 pints), mebendazole 2 x 100 mg for 3 days, and iron tablet. The stool (314 grams) was then sent for Kato-Katz Technique examination which showed 16.137 hookworms eggs per gram of stool.
Patient’s wife and his 3 children was then screened with full blood count and stool for ova examination, which showed hypereosionphilia in all family member and found hookworm eggs in his youngest son’s stool. Mebendazole was given to all patient’s family members. Patient’s symptoms had much improved and his hemoglobin raised to 8.5 g/dl. Before he was discharge, he was taught about health education programs and stressed on important of prevention and personal hygiene, such as washing hands before eating, do not walk barefoot in known infected area, do not defecate in the open, but rather in toilets, access to clean water.
On subsequent outpatient visits 1 week after discharged, his hemoglobin level increased to 9.5 g/dl, no further diarrhea occurred and no stool ova was found.
Discussion
Hookworm infection is a relatively common cause of anemia in endemic areas. An estimated 576-740 million people are infected, especially in poor, rural areas in the tropics and subtropics, making hookworm infection one of the most common chronic infections worldwide. Ancylostoma duodenale and Necator americanus are the major species of hookworms that infect humans.
Hookworms live in the small intestine, their eggs are eliminated through human stool and in the appropriate conditions they hatch in the soil to release larvae that mature into infective filiariform larvae. Infection is transmitted by larval penetration into human skin, from where larvae migrate into the blood vessels and are carried to the lungs and ultimately to the pharynx, where they are swollen and thereby complete their life cycle in the intestine. Adult worms attach to the mucous wall of the small intestine where they are able of softening the wall of intestinal villi and breaking blood capillaries, mainly feeding on blood and tissue fragments. Adult hookworms also release anticlotting agents to ensure blood flow. Ancylostoma duodenale may also be transmitted through ingestion of larvae. They can develop into mature worms in the intestine without migrating through the lung to the intestine.
As a farmer, and lived in rural area, risk of hookworms infection is high. Patient may have been infected either by larval penetration into skin or through ingestion of larvae, due to poor personal hygiene, habits, and sanitation. The gastrointestinal symptoms caused by hookworm infection include nausea, diarrhea, vomiting, abdominal pain, and abdominal fullness. A definitive diagnosis of hookworm infection depends on discovery of eggs in the stool; however, samples may be negative during the early stage of hookworm infection. Chronic infection is asymptomatic or symptoms and signs resulting from iron-deficiency anemia can be found. It has been estimated that one worm can take up to 0.1 to 0.2 ml blood per day. The daily output of eggs per female worm is around 9000 for N. americanus and can be as high as 10 000 for A. duodenale.
Patient had a past history of hookworm infections and took prophylaxis therapy for few years but then he did not continue. Likely this patient reinfected and had a chronic hookworm infections, but did not seek treatment and remained asymptomatic until lately he developed gastrointestinal symptoms with poor nutritional status and his iron store depleted and developed sign of chronic and severe iron deficiency anemia, reflected by low hemoglobin, MCV, MCH, depleted iron store, and koilonychia. The impact of hookworm infection on iron stores depends on the intensity of infection as well as the amount of iron consumed in the diet. Based on the daily output of eggs per female worm, weight of stool sample (314 grams) and Kato-Katz stool examination which showed 16.137 hookworms eggs per gram of stool, we able to estimate that this patient might have 506 adults hookworms in his intestine.
Based on the presence or absence of anemia, presence or absence of eosinophilia, patients with hookworm infection was classified into 5 stages as Stage 1. Very early stage of hookworm infection [no anaemia and no eosinophilia]. Stage 2. Early stage of hookworm infection [no anaemia but had eosinophilia]. Stage 3. Stage of mild hookworm infection [mild anaemia]. Stage 4. Stage of moderate hookworm infection [moderate anaemia]. Stage 5. Late stage of hookworm infection or stage of severe hookworm infection [severe anaemia].
An increase in the peripheral blood eosinophils has long been recognized as a characteristic feature of helminth infection, consumption of medications, allergic disorders, and autoimmune and malignant diseases. However, parasitic infection is the major cause of eosinophilia in developing countries. Eosinophilia can be detected in 30% to 60% of cases and its peak usually coincides with the development of adult hookworms in the intestine, which in turn occurs 5 to 9 week after the onset of the infection.
In this case, due to initial microcytic hypochromic anemia with hypereosinophilia, we highly suspected helminth infection, and sent stool for ova examination. Confirmation diagnosis was made based on finding hookworm eggs from stool examination. We have classified this case as stage 5 which is late stage of hookworm infection with severe anemia.
Hookworm infection is a treatable disease and results in complete recovery. The 2 most commonly used drugs for treatment are mebendazole and albendazole, both of which are benzimidazole anthelmintic drugs. Three consecutive daily doses of either drug improve both cure and egg reduction rates.
The patient was treated with mebendazole and supportive measures for anemia, and his physical condition much improved. On subsequent outpatient visits, his hemoglobin level increased, no further diarrhea occurred and no stool ova was found. Patient’s family member was also treated with mebendazole because of presumed hookworm infections due to hypereosinophilia found in their blood. Patient and family member was taught about health education programs, sanitation and stressed on important of prevention and personal hygiene.
Conclusions
Hookworm infection is a treatable disease. In case of gastrointestinal symptoms, sign of iron deficiency anemia and hypereosinophilia, the possibility of hookworm infections must be considered particularly in endemic areas. A definitive diagnosis of hookworm infection depends on discovery of eggs in the stool. Benzimidazole anthelmintic drugs such as mebendazole and albendazole are commonly used drugs for treatment.
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