These are other enteric waterborne viruses of importance with noroviruses being the major ones. They are very stubborn pathogens which are able to withstand almost any method of water purification. When one gets infected by these viruses at an early age, the chances of re-infection at adulthood are very slim as they will already be immune to the pathogens. The norovirus pathogen however, infects people of all ages and one gets it by ingesting food or water that has been contaminated by faeces. Symptoms of infection are: nausea, vomiting, headache, fever, abdominal pains and cramping.
This virus causes also causes diarrhoea. Immunity to norovirus is short lived so it keeps on recurring throughout one’s lifetime. Bacteria The human body contains bacteria which are found in the gut and on the skin, which is home to ‘friendly’ bacteria. The work of the bacteria is to protect the body from invasion by harmful bacteria. Plants and other animals can act as hosts to bacteria. Soil can also carry the bacteria, if an infected animal or human defecated on it. Salmonella In humans, salmonellosis occurs in three types which are gastroenteritis, septicemia
and enteric fever. As we have seen before, gastroenteritis is a disease that attacks the colon with diarrhoea and abdominal pains as its symptoms. Humans who are asymptomatic (those carrying the pathogen but don’t show symptoms) can also be carriers. The hosts of the pathogen could either be wild or domesticated animals. There is the S. typhi which causes the enteric fever, in other words the typhoid fever and then we have S. paratyphi, also known as the paratyphoid fever. S. typhi lasts longer than S. paratyphi. Septicemia, which is also caused
by salmonella, causes meningitis, pneumonia and endocarditis. The victim has very high fever and chills, may become anorexic and will have bacteremia. Contamination of salmonella occurs by ingesting food or water contaminated with faecal matter. One can also get the pathogen by eating meat which is already infected. Salmonella in AIDS victims can be very dangerous. To begin with, their immune systems are already compromised and it not only relapses but can also cause death. According to Celum et al, authors of Incidence of Salmonellosis in Patients with AIDS,
(1998), Salmonellosis is about twenty times more common in those with AIDS than those without. Treating Salmonellosis has proven to be quite hard, especially in AIDS patients, therefore long term treatment with antibiotics is usually advised. Shigella In this family of pathogens is a genus known as shigella, which invades the intestinal muscles to cause acute gastroenteritis. Shigellosis is a symptomatic disease that is characterized by nausea, diarrhoea and vomiting, which makes it difficult for the patients to keep down any food they’ve eaten. Other symptoms include fever and cramps.
Shigella can be found in the natural environment; water, plants, soil, human and animal wastes. According to Perdomo O. J. J. , et al authors of Experimental Medicine, illnesses in a patient will depend on their age and how strong or weak their immune systems are; one may also suffer complications such as seizures, renal failure, sepsis and haemolytic uraemia syndrome. When shigella attacks the blood, it causes bacteraemia, however, such cases are very few. But, when it does occur, it is usually because the patient’s immune system has been majorly compromised and is suffering from AIDS.
The major organ of attack is usually the intestine. Shigellosis is most prone in areas where sewages are rarely treated and places where there is poor hygiene. Shigella can be transmitted through the direct route, by drinking water or food that is already contaminated or the indirect route, from patients through faecal-oral contact. It usually occurs in slums in developing countries, nursing homes, Internally Displaced People’s (IDP) camps, refugee camps and daycare centers. Outbreaks can also occur on water surfaces of lakes, rivers and communal swimming pools.