Tropical Medicine

Nick Beeching, Geoff Gill

• Publisher: Wiley-Blackwell
• Year: 2014
• Print ISBN: 9780470658536
• eBook ISBN: 9781118734568
• Edition: 7
• Topic: Medicine
• Subtopic: Infectious Diseases

Providing a comprehensive introduction to the study of tropical medicine, this new edition has been thoroughly revised and updated to include new content and more illustrations and clinical photographs to aid understanding. Now fully supported by a companion website containing hundreds of interactive multiple-choice questions, and available in a range of digital formats, Tropical Medicine Lecture Notes is the perfect resource for study and revision, and is the ideal companion for those practising medicine in tropical and sub-tropical regions.

• New edition of the best-selling tropical medicine textbook
• Brand new chapters covering Ophthalmology and Neglected Tropical Diseases (NTDs)
• Increased coverage of malaria, tuberculosis and HIV/AIDS
• More colour illustrations and photographs for greater clarity and understanding
• Fully supported by a companion website at www.lecturenoteseries.com/tropicalmed containing figures and summaries from the book in PowerPoint format, and hundreds of interactive MCQs (written by Dom Colbert)
• Now available in a range of digital formats - perfect for on-the-go study and clinical practice

Part 1
A general approach to syndromes/symptom complexes

1
Gastrointestinal presentations

Nick Beeching and Mike Beadsworth

Liverpool School of Tropical Medicine

The most important gastrointestinal presentation in the tropics is diarrhoea, and the majority of this chapter is devoted to this problem. However, other presentations of gastrointestinal disease are discussed first.

Dysphagia/odynophagia

Significant recent-onset dysphagia should always raise the possibility of oesophageal carcinoma. This malignancy is particularly common in certain parts of the tropics, e.g. some areas of Central and East Africa. Oesophageal candidiasis (HIV-related) is also a common cause of tropical dysphagia, together with ulceration due to herpes simplex and cytomegalovirus infections in patients with HIV. In South America, the mega-oesophagus of Chagas’ disease should be considered. Finally, achalasia, peptic strictures, corrosive chemical ingestion and foreign bodies (fish bones especially in some areas) may also be important causes of impaired swallowing.

Haematemesis

In all areas of the world, an upper gastrointestinal haemorrhage can be caused by peptic ulceration, gastritis, oesophagitis, and gastric or oesophageal carcinoma. Gastritis, gastric erosions and gastric ulcers may be drug-related, e.g. corticosteroids and non-steroidal anti-inflammatory drugs (NSAIDs). Helicobacter pylori is recognized globally as a major cause of gastric and duodenal inflammation and/or ulceration. Oesophageal varices may be a particularly common cause of haematemesis in many tropical areas – at least 25% of all cases in some series. The underlying liver disease can be the late result of alcohol abuse, chronic viral hepatitis, or schistosomal hepatic fibrosis. Liver disease related to metabolic syndromes is becoming a global probem.

Abdominal pain

In ‘Western’ populations, severe abdominal pain can result from appendicitis, mesenteric adenitis, perforated peptic ulcers, biliary colic, cholecystitis and intestinal obstruction (commonly because of adhesions or malignancy). The irritable bowel syndrome and variants are common and in some cases may be triggered by infections, particularly by organisms that cause invasive colitits. This list is far from exhaustive, but serves to demonstrate that the spectrum of causes in the tropics is much wider. The following ‘exotic’ causes of acute severe abdominal pain may need to be considered.

• Abdominal tuberculosis
• Amoebic colitis (including perforation)
• Amoebic liver abscess (which may rupture)
• Ectopic ascariasis (e.g. biliary and/or pancreatic obstruction)
• Hydatid cyst rupture
• Hyperinfection syndrome of strongyloidiasis
• Intestinal obstruction caused by Ascaris lumbricoides
• Sickle cell crisis
• Splenic rupture
• Typhoid (including typhoid perforation)

Malabsorption

Malabsorption can be a feature of infection with Giardia lamblia, Strongyloides stercoralis, intestinal tuberculosis (TB) infection, as well as AIDS. Perhaps the most common cause, however, is the temporary lactase-deficient situation that may occur after any significant acute infective diarrhoeal illness. Milk and milk products may need to be avoided, although yoghurt is usually tolerated, because of its high bacterial lactase content.

Tropical sprue

A particularly well-described form of tropical malabsorption is ‘tropical sprue’. This occurs predominantly in India and South East Asia, as well as the Caribbean and Central America. Patients develop non-bloody diarrhoea (sometimes steatorrhoea) often with abdominal bloating and significant weight loss. There may be a history of initial acute diarrhoeal illness, which is thought to be the precipitant (although the exact mechanism is unknown). As well as biochemical features of malabsorption, duodenal biopsy typically shows partial villous atrophy. The illness can be prolonged and debilitating. Traditional treatment with tetracycline (for associated bacterial small bowel overgrowth) and folic acid is often highly effective.

Diarrhoea

Diarrhoeal illness is one of the most important causes of morbidity and mortality in the tropics, causing over 6 million deaths per year. It is the fifth most common communicable cause of death worldwide and is clearly linked with poor hygiene and contamination of water and food. A wide variety of viral, bacterial and parasitic pathogens have been implicated in the pathogenesis of diarrhoea but it is impossible and unnecessary to test for all of these in individual cases. Systematic review of epidemiological, clinical and host factors usually enables a sensible working aetiological diagnosis to be established. The working diagnosis can be used to decide whether specific investigation should be performed, or to direct empirical antimicrobial therapy in the minority of cases in which it is required. The mainstay of management of diarrhoeal illness is the assessment and maintenance of appropriate fl...

Table of contents

• Cover
• Title Page
• Copyright
• Contributors
• Preface
• List of abbreviations
• How to use your textbook
• About the companion website
• Part 1: A general approach to syndromes/symptom complexes
• Part 2: Major tropical infections
• Part 3: Other tropical diseases
• Index
• User License Agreement