Enteric (Typhoid) Fever Causes, Symptoms, Treatment
Enteric fever is a systemic clinical syndrome produced by a certain species of Salmonella. It includes typhoid fever whereby a microbe causing is Salmonella typhi and paratyphoid fever (Salmonella paratyphi A and B).
Typhoid fever is a systemic infectious disease with characterizing symptoms being high continuous fevers, malaise and involvement of the lymphoid tissues as well as spleen.
Paratyphoid fever may present with gastroenteritis/transient diarrhoea.
Moreover, contamination of sources of water or food used by many people can cause an outbreak.
Did you know…?
Humans are the only source and reservoir for S. typhi and therefore, a direct or indirect contact with an infected person is necessary for an infection to occur.
Transmission is via faecal-oral route. The salmonella is passed out in faeces and urine of carriers. It is spread mainly through contaminated water and food.
It is usually common at the end the dry season and start of rains. Contamination of food normally occurs from the hosts or undiagnosed patients.
It is also common in areas where there’s insufficient water to wash hands.
Stomach acidity is due to gastric acid. It is an important determinant of susceptibility to salmonella.
Those that survive the gastric acidity escape into the small intestine where they attach into the lining and in verge into the lymphatics.
They then reach the blood stream via the thoracic duct hence causing transient bacteremia again!
In addition, the gall bladder is usually affected through the biliary system. A proliferation in the gall bladder walls produces higher numbers of salmonella. These are then emptied into the intestines and out into the environment through the faeces for a very long time if the patient is not treated.
Urinary carriers are seen particularly in areas where Schistosoma haematobium infection is common i.e. Bilharzia.
Symptoms (Clinical Picture)
Incubation period is 2-3 weeks depending on the amount of ingested innoculum.
5 years and above, the onset is gradual and the initial symptoms include:
- Loss of appetite
- Abdominal pains
In the early course of infection, diarrhoea may be present but this gives way to constipation which becomes a more prominent symptom.
Fever rises upto 40°C in week 1. The Second week, you sustain the fever and fatigue, you lose appetite and abdominal pain increase in severity.
The affected organs especially the liver (hepatomegally) and spleen (spleenomegally) and both become tender.
Your abdomen also becomes distended and tender due to ulcers in the lymphatic tissues of the intestines. These ulcers may cause bleeding and perforations in the third week.
Patients under 5 years: It rarely inflicts the age-group. If it occurs, it is mild with diarrhoea and then presents with mild fever, malaise and you/doctors can easily diagnose it as a viral infection.
Firstly, it is through stool and blood cultures. Blood cultures are positive early in the course of infection because of the intermittent and low-level bacteremia.
Therefore, you should be obtaining blood cultures repeatedly, as always.
In addition, stool and urine cultures are always positive at the first week of infection and sometimes in chronic carriers.
In fact, bone marrow culture is the most sensitive. Widal test becomes positive at the end of the first week.
Antibiotic therapy is the most important in treating typhoid infection and because of drug resistance, doctors are leaving the choice of antibiotic to sensitivity and resistance patents in different areas.
The drugs of choice are usually:
- Quinolones e.g. Norfloxacin.
Prevention and Control
Actually, it is as of other diarrhoeal diseases but it is important to identify carriers who work as food handlers. REASON…? It is because they are likely to transmit typhoid fever.
Typhoid vaccine is available and you can give it at 2 years of age , a booster at 5 years and 10 years of age.
Good water supply can improve food hygiene at the best control measures.