Zoonotic diseases are a group of communicable diseases that are transmissible from vertebrate animals to humans through direct contact or through food, water, and the environment (WHO, no date).

Dengue is a mosquito-borne disease that is caused by a virus of the Flaviviridae family and transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, A. albopictus (WHO, 2020).

Hepatitis A is an acute vaccine-preventable viral liver disease caused by the hepatitis A virus. The infection can cause mild to severe illness and is epidemic prone (WHO, 2020).

Vector-borne diseases are diseases transmitted by a living being, usually an arthropod vector, to a vertebrate host (Verwoerd, 2015).

Blood-borne viruses are viruses transmitted by direct contact with infected blood or other body fluids (WHO, 2012).

Chikungunya is a mosquito-borne viral infection caused by the chikungunya virus. It causes fever and severe arthralgia (joint pain) which is often debilitating. The disease can be endemic and epidemic in countries (WHO, 2020).

Animal trypanosomosis is a lethal parasitic disease caused by unicellular organisms named trypanosomes. The disease is cyclically transmitted by the bite of infected tsetse flies and it affects both humans ‘sleeping sickness’ and livestock ‘nagana’ (FAO, 2020).

Diarrhoeal diseases are infectious diseases, contaminants and other causes of diarrhoea. Diarrhoea is defined as the passage of three or more loose or liquid stools per day, or more frequently than is normal for the individual (WHO, no date). This includes the three clinical types of diarrhoea: acute watery diarrhoea – lasts several hours or days, and includes cholera; acute bloody diarrhoea – also called dysentery; and persistent diarrhoea – lasts 14 days or longer (WHO, 2017).

Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. It is preventable and curable. In 2018, there were an estimated 228 million cases of malaria worldwide and the estimated number of malaria deaths stood at 405,000 (WHO, 2020).

Escherichia coli (E. coli) is a bacterium commonly found in the gut. Some strains can cause serious food poisoning, leading to diarrhoea and sometimes to life-threatening complications including haemolytic uraemic syndrome (WHO, 2018).