Every year in Nigeria, two outbreak-prone illnesses tend to make the news together: cholera and Lassa fever. They are very different diseases, but both can move fast, both are common in parts of the country, and both can be deadly if you wait too long before acting. Cholera spreads through dirty water and food and causes sudden, heavy watery diarrhoea. Lassa fever spreads mainly from rats to people and often starts looking just like malaria or typhoid. This guide explains how to tell them apart, the danger signs that mean go to hospital now, and how to protect your household. It is general information to help you act early, not a diagnosis.
Two different diseases, often confused
Cholera is a bacterial infection of the gut caused by Vibrio cholerae. You catch it by swallowing water or food contaminated with faeces, which is why it flares during the rainy season, in flood-affected areas, and in crowded places where sanitation is poor. Lassa fever is a viral haemorrhagic fever. The main source is the multimammate rat, which is common in many Nigerian homes; people get infected by eating or touching food and surfaces soiled by rat urine and droppings, and sometimes from an infected person's body fluids. The NCDC tracks Lassa fever heavily during the dry-season peak, roughly December to April, though cases appear all year.
Cholera symptoms
Cholera can hit suddenly, sometimes within hours of infection. The hallmark is profuse, painless watery diarrhoea often described as looking like rice water (pale and cloudy), usually with vomiting. There may be little or no fever. The real danger is not the diarrhoea itself but how quickly it drains the body of fluid and salts. A previously healthy adult can become dangerously dehydrated in half a day. Many people have mild illness, but severe cases can kill within hours if fluids are not replaced.
Lassa fever symptoms
Lassa fever is sneaky because it often begins like a routine fever. Early on you may have fever, general weakness, headache, sore throat, muscle pain, chest pain, nausea, vomiting and diarrhoea. About 80 percent of infections are mild or have no obvious symptoms. But in some people it progresses to bleeding from the gums, nose, eyes or other sites, facial swelling, difficulty breathing, confusion and shock. A persistent fever that is not responding to malaria and typhoid treatment, especially if you have rats around your home, is a reason to think about Lassa fever and get tested.
Telling them apart at a glance
The quickest mental shortcut: cholera is mostly about sudden, massive watery diarrhoea and dehydration with little fever, while Lassa fever is a stubborn fever-and-aches illness that can later bleed. The table below is a rough guide only. Both still need proper testing, because typhoid, malaria, food poisoning and other infections can overlap with either picture.
| Feature | Cholera | Lassa fever |
|---|---|---|
| Main spread | Contaminated water and food | Rat urine/droppings; infected body fluids |
| Onset | Sudden (hours) | Gradual fever over days |
| Key sign | Heavy rice-water diarrhoea, vomiting | Persistent fever, weakness, later bleeding |
| Fever | Often mild or none | Common, persistent |
| Peak season | Rainy season, floods | Dry season (Dec to Apr), all year |
Danger signs: get emergency care now
Go to the nearest hospital or call 112 or 199 immediately if you or a child have: many watery stools with sunken eyes, no urine, severe weakness or confusion (signs of dangerous dehydration); inability to keep fluids down; a high fever that will not break; any unexplained bleeding from gums, nose, eyes, urine or stool; facial swelling, fast breathing or fainting. For a baby or elderly person, severe diarrhoea is an emergency much sooner. Do not wait at home to see if it passes.
When to see a doctor
For mild, early symptoms, you can start a conversation with an MDCN-verified doctor quickly through GoDoctor. A telemedicine consult is useful to assess your risk, guide oral rehydration for loose stools, arrange the right tests, and tell you plainly whether you need to head to a facility. But telemedicine has limits: cholera with heavy dehydration and any suspected Lassa fever with fever or bleeding need in-person hospital care, often isolation and specific treatment. Use an online doctor to triage fast and to avoid delay, not as a substitute for emergency care when danger signs are present.
- You have loose stools but can still drink and pass urine, and want guidance on rehydration
- A fever has lasted more than a couple of days and malaria or typhoid treatment is not helping
- You live or work where there are rats, or where there is an active outbreak nearby
- You need a prescription, a referral, or help deciding whether to go to hospital
- Someone in your home is already confirmed with cholera or Lassa fever and you have new symptoms
Testing and diagnosis
Cholera is often diagnosed clinically during an outbreak, with stool tests and rapid tests used to confirm the bacteria. The priority is treatment first, especially rehydration, not waiting endlessly for results. Lassa fever is confirmed by a PCR blood test done at designated NCDC laboratories; ordinary clinics cannot rule it out with a malaria or typhoid test alone. If a doctor suspects Lassa fever, you may be referred to a treatment centre and the case reported to public health authorities. GoDoctor can help you understand which tests apply and, where appropriate, arrange a home sample or point you to the right facility.
Treatment and management
For cholera, rehydration is everything. Most people recover with oral rehydration salts (ORS) taken steadily; severe cases need intravenous fluids in hospital and sometimes antibiotics to shorten the illness. Keep sipping ORS even while waiting for care. For Lassa fever, the antiviral ribavirin works best when started early, which is exactly why catching a stubborn fever quickly matters. Severe cases need hospital support and isolation to protect family and health workers. Never self-medicate with random antibiotics for either illness; use a doctor's guidance and only medicines from NAFDAC-registered, reputable pharmacies.
Prevention
Prevention for these two diseases comes down to clean water and a clean home. For cholera, treat your water and protect your food. For Lassa fever, keep rats out and store food safely. Simple, consistent habits protect a whole household more than any single intervention.
- Drink only water you have boiled, properly filtered, or that is sealed and safe; treat stored water during floods or outbreaks
- Wash hands with soap after the toilet and before eating or cooking; this stops cholera spread
- Eat food that is freshly cooked and hot; wash fruits and vegetables with safe water
- Store grains, garri and foodstuff in tightly covered containers so rats cannot reach them
- Block rat entry points, keep surroundings clean, and avoid drying food on the floor where rats roam
- Do not catch or eat rodents; dispose of refuse properly and keep the kitchen clean
- Ask a doctor about the oral cholera vaccine if you live in or are travelling to a high-risk or outbreak area
FAQ
Is cholera the same as ordinary running stomach? No. Many causes of loose stool are mild, but cholera produces large amounts of watery, rice-water stool that can dehydrate you within hours. If diarrhoea is heavy and you feel very weak or stop passing urine, treat it as an emergency and get to hospital.
My fever is not responding to malaria drugs. Could it be Lassa fever? It can be, especially during the dry-season peak or if you have rats around your home. It could also be typhoid, a resistant malaria, or another infection. Do not keep guessing at home; speak to a doctor and get the right blood tests, which for Lassa fever means a PCR test at an NCDC laboratory.
Can I be treated for these on GoDoctor without going to a hospital? You can use GoDoctor to assess symptoms early, get rehydration advice, arrange testing and decide quickly whether you need a facility. But confirmed cholera with dehydration and suspected Lassa fever need in-person hospital care, often with isolation. Online care is for fast triage, not for managing severe outbreak disease at home.
How do I protect my family during an outbreak? Treat and store water safely, wash hands with soap, eat hot freshly cooked food, keep food in rat-proof containers, and seal up rat entry points. If anyone develops danger signs, call 112 or 199 or go to the nearest hospital straight away.