Typhoid Fever

Typhoid fever is a serious bacterial infection caused by Salmonella typhi, transmitted through contaminated food and water. It is a major public health problem in Nigeria and other low- and middle-income countries where access to safe drinking water and sanitation is limited. Without treatment, typhoid can lead to severe and life-threatening complications including intestinal perforation and internal bleeding. With proper antibiotic therapy, most patients recover fully. A related but milder illness, paratyphoid fever, is caused by Salmonella paratyphi.

Typhoid fever develops gradually over 1 to 3 weeks after exposure. Symptoms include: • Sustained, progressively rising fever (often reaching 39–40°C / 102–104°F) • Headache — often severe and persistent • Weakness and fatigue • Abdominal pain and discomfort • Loss of appetite • Nausea and vomiting • Diarrhoea or constipation (both can occur at different stages) • Dry cough in early stages • Rose-coloured spots on the abdomen (rose spots) — seen in lighter-skinned individuals • Enlarged spleen and liver • Slow heart rate relative to the degree of fever (relative bradycardia) In severe cases: confusion, disorientation, and in advanced untreated disease, intestinal bleeding or perforation.

Typhoid fever is caused by the bacterium Salmonella enterica serotype Typhi (S. typhi). The infection spreads through the faecal-oral route: • Drinking water contaminated with faeces from an infected person • Eating food handled by someone who is infected and has not washed their hands properly • Eating raw fruits or vegetables washed with contaminated water • Eating shellfish from contaminated water sources After being swallowed, S. typhi passes through the gut into the bloodstream. It multiplies in the liver, spleen, and bone marrow, then re-enters the bloodstream causing the prolonged fever and systemic illness. Some people become chronic carriers — they harbour the bacterium in their gallbladder without symptoms and can shed it in their faeces, unknowingly spreading the disease to others.

• Drinking untreated or poorly treated water from wells, streams, or boreholes • Eating street food or food handled under poor hygienic conditions • Lack of access to safe sanitation (open defecation or shared pit latrines) • Living in or travelling to endemic areas (Nigeria, other parts of sub-Saharan Africa, South Asia) • Living or working with a known typhoid carrier • Children aged 5–15 years (highest burden group in endemic areas) • Weakened immune system (e.g., HIV, sickle cell disease, malnutrition) • Low vaccination coverage in the community

Without prompt treatment, typhoid fever can progress to life-threatening complications in the third week of illness: • Intestinal haemorrhage — bleeding from ulcers in the bowel wall • Intestinal perforation — a hole forms in the bowel, leaking contents into the abdomen; causes severe pain and peritonitis, requiring emergency surgery • Peritonitis — infection of the abdominal cavity • Encephalopathy — brain dysfunction causing confusion, agitation, or psychosis • Myocarditis — inflammation of the heart muscle • Hepatitis — liver inflammation • Relapse — symptoms return 2–3 weeks after apparent recovery in a minority of cases • Death — without treatment, case fatality rate is 10–30%; with treatment, less than 1%

Safe water and food practices: • Drink only boiled, bottled, or chlorinated water • Wash hands thoroughly with soap and water before eating and after using the toilet • Eat food that is fully cooked and served hot • Avoid raw salads, unpeeled fruits, and street food of uncertain hygiene • Avoid ice in drinks unless made from safe water Vaccination: • Typhoid conjugate vaccines (TCV) are recommended for children from 6 months of age in endemic settings and for travellers to endemic areas • Vaccination does not eliminate the need for safe food and water practices Sanitation: • Use proper latrines or toilets — open defecation contributes to contamination of water sources • Dispose of sewage safely and support community sanitation programmes