When the rains settle in across Nigeria, from Lagos and Port Harcourt to Abuja and the southeast, a familiar set of illnesses comes with them. Mosquitoes breed in stagnant water, floods overwhelm drainage and contaminate wells and boreholes, and food stands too long in damp heat. The result is a yearly spike in rainy season illness in Nigeria, led by three big names: malaria, cholera and typhoid fever. This guide explains how each one behaves, how to lower your risk at home, and the warning signs that mean you should stop self-treating and see a doctor today. It is health information, not a diagnosis, but knowing what to watch for can save a life in your household.
Why illness rises when the rains come
Three things change in the wet season. First, pools of standing water in gutters, discarded tyres, buckets and blocked drains become breeding grounds for the Anopheles mosquito that carries malaria. Second, flooding pushes sewage and rubbish into the same water people drink, cook with and wash food in, which spreads cholera and typhoid through the faecal-oral route. Third, power and storage problems mean food and water sit longer in warm, humid conditions, giving bacteria more time to multiply. The diseases differ, but the season hands them all the same advantage: water you cannot trust and mosquitoes you cannot avoid.
Malaria: the fever that follows the mosquito
Malaria remains Nigeria's most common rainy season illness. It typically starts with fever, chills and shivering, headache, body and joint aches, and tiredness, often a week or two after a mosquito bite. Because so many people assume every fever is malaria and buy drugs over the counter, the single most important step is a test first. A simple rapid diagnostic test (RDT) or microscopy confirms whether it is truly malaria before you take an antimalarial. Treating blindly wastes money, masks other illnesses like typhoid, and feeds drug resistance. Sleep under a treated net, clear standing water around your compound weekly, and use repellent at dusk. If your test is positive, complete the full course of treatment even when you start feeling better.
Cholera: watery diarrhoea that drains you fast
Cholera is the most dangerous of the three because of how quickly it dehydrates. The classic sign is sudden, profuse, watery diarrhoea, sometimes described as rice-water stool, often with vomiting. The NCDC declares cholera outbreaks most years during the rains, usually linked to contaminated water and poor sanitation in crowded areas. A person can go from well to severely dehydrated within hours. The first response at home is oral rehydration salts (ORS), mixed correctly and sipped continuously, while you arrange care. Do not wait to see if it passes. Severe cholera needs urgent medical attention and intravenous fluids that you cannot give at home.
Typhoid fever: the slow-building fever people miss
Typhoid, caused by Salmonella Typhi, spreads through contaminated food and water, just like cholera, but it behaves differently. Instead of sudden diarrhoea, it builds gradually: a fever that climbs over several days, headache, weakness, stomach pain, loss of appetite, and sometimes constipation rather than diarrhoea. Because the early picture overlaps with malaria, the two are often confused, and people sometimes carry both at once. The reliable confirmation is a proper blood culture rather than the widely used Widal test, which gives many false results. Untreated typhoid can lead to serious gut complications, so a fever lasting more than three days deserves a proper assessment, not another round of guesswork.
Telling them apart at a glance
| Illness | Main early signs | How it spreads | First step |
|---|---|---|---|
| Malaria | Fever, chills, headache, body aches | Mosquito bite | Get an RDT or blood test before treating |
| Cholera | Sudden watery diarrhoea, vomiting | Contaminated water and food | Start ORS, seek urgent care fast |
| Typhoid | Fever rising over days, weakness, stomach pain | Contaminated water and food | See a doctor, ask for a blood culture |
This table is a guide, not a diagnosis. Symptoms overlap heavily, and it is common to have more than one infection in the same season. Testing is what separates them, which is why a clinician and a lab beat self-treatment every time.
Practical prevention for your home
- Drink only water you trust: boil it, filter it, or use sachet or bottled water with an intact seal, especially during flooding.
- Wash hands with soap before eating and cooking and after using the toilet; keep a hand-wash point at your gate during outbreaks.
- Eat food hot and freshly cooked; avoid food and ice that has stood out, and wash fruits and vegetables in clean water.
- Sleep under an insecticide-treated net every night and empty containers, gutters and tyres of standing water weekly.
- Keep oral rehydration salts (ORS) in the house before the season peaks so you are not searching for them during an emergency.
- Store food covered and refrigerated where possible, and throw away anything that smells off rather than reheating it.
Go to hospital now if you see these
Call 112 or 199, or go to the nearest hospital immediately, for any of these danger signs: many watery stools with sunken eyes, very dry mouth, no urine or extreme weakness (severe dehydration); high fever with confusion, drowsiness or seizures; difficulty breathing; a fever that does not improve after three days; severe abdominal pain; blood in stool or vomit; or any fever in a baby, a pregnant woman or an elderly person. These are emergencies, not wait-and-see situations.
When to test and when to see a doctor
The honest rule for the rainy season is: test, do not guess. If you have a fever, do not assume it is malaria and buy drugs at the chemist. A GoDoctor doctor can assess your symptoms by video, audio or chat, arrange a home lab test such as a malaria RDT, blood culture or stool test at a fixed indicative price, and read the results with you. If you need medicine, an e-prescription and delivery can be arranged, and a home nurse or doctor visit booked if you are too weak to travel. For anyone who cannot easily reach a clinic in the rain, the option to see a doctor online means you start the right care quickly instead of losing days to the wrong treatment. Where the danger signs above appear, skip the app and head straight to hospital.
FAQ
Is every fever during the rainy season malaria? No. Fever is also the leading sign of typhoid and can appear in many other infections, and people sometimes have malaria and typhoid together. That is why a test before treatment matters, rather than assuming and buying antimalarials over the counter.
How can I tell cholera from ordinary stomach upset? Cholera causes sudden, large amounts of watery diarrhoea that dehydrate you very fast, often with vomiting, and is most common during outbreaks the NCDC reports in the rains. If diarrhoea is heavy and you feel weak, dizzy or thirsty, treat it as urgent, start ORS and seek care immediately rather than waiting.
Why do doctors say the Widal test is not reliable for typhoid? The Widal test commonly gives false positives and false negatives, so a positive result alone does not confirm typhoid. A blood culture is far more accurate, and a GoDoctor doctor can arrange the right test and interpret it with you instead of treating on a Widal result alone.
Can I just consult a GoDoctor doctor online instead of going to a clinic? For many rainy season fevers and stomach complaints, yes, you can see a doctor online, get a home lab test and an e-prescription with delivery. But if you have danger signs like severe dehydration, confusion, breathing difficulty or fever in a baby, pregnant woman or elderly person, call 112 or 199 or go to the nearest hospital straight away.