Introduction

This study session focuses on three significant health problems which are common in communities where there is poor hygiene and sanitation, and where people find it difficult to keep their environment clean. In this study session, we contrast three conditions where the local environment makes an important contribution:

• Trachoma, a potentially blinding eye disease caused by bacteria, but flies are a strong environmental factor in its transmission;
• Scabies, a persistent irritating rash caused by tiny crawling mites that burrow into the skin;
• Podoconiosis, a form of elephantiasis (swollen limbs with thickened skin) that is not caused by an infection at all – but by irritating particles of red clay soil causing a damaging reaction in the skin.

A common feature of these diseases is the lack of clean water for washing, and lack of education about their causes and how to prevent them. As you will see, washing the body and clothes regularly and disposing of rubbish safely is the key to prevention and control.

In this study session, you will learn about the causes, modes of transmission, treatment and prevention of trachoma, scabies and podoconiosis. A better understanding of these diseases will help you to diagnose, treat or refer patients and educate your community on prevention measures.