Dengue and Malaria in Older Adults: Warning Signs

Why older adults are at higher risk

• Atypical illness: fever may be mild, and the main sign may be weakness, confusion, falls, loss of appetite or a drop in blood pressure; see fever in older adults: why it can be subtle and when to call.
• Dehydration develops fast with fever, sweating and vomiting; see hydration for older adults: how much and how to remember.
• Other conditions such as diabetes, heart disease, kidney disease, lung disease and cancer make complications likelier; see diabetes after 60: a home care guide and chronic kidney disease: home care guide.
• Blood thinners and anti-inflammatory medicines increase bleeding risk in dengue; the doctor should know all medicines, and you should never stop a prescribed medicine on your own; ask the doctor the same day; see atrial fibrillation and blood thinners: a family guide.
• Slower recovery and risk of delirium; see delirium in older adults.
• Living alone, so illness goes unnoticed; see home safety for seniors living alone.

Dengue: what it is

Dengue is a viral infection spread by Aedes mosquitoes, which breed in clean standing water and bite mainly during the day. Cases peak during and after the monsoon. There are four types of the virus, so a person can be infected more than once, and a second infection can be more severe.

### Typical course

Febrile phase (days 1 to 3 or 4): sudden fever, severe headache, pain behind the eyes, muscle and joint pain ("break-bone" ache), nausea, vomiting, flushing, a rash, and sometimes mild bleeding such as nosebleeds or gum bleeding. In older adults, fever may be low.

Critical phase (around days 3 to 7, often as the fever falls): this is the dangerous period. As the temperature drops, plasma may leak from blood vessels. Warning signs include: - Severe or continuous abdominal pain or tenderness. - Persistent vomiting. - Bleeding from gums, nose or vagina, blood in vomit or stools, black stools. - Restlessness, lethargy, drowsiness or confusion. - Cold, clammy hands and feet; fast, weak pulse; low blood pressure. - Reduced urine; rapid breathing; swelling of the abdomen or legs. - Rapid fall in platelet count on blood tests, with rising haematocrit.

A person who seems to be "getting better" because the fever is gone may in fact be entering the critical phase. Keep monitoring.

Recovery phase (days 7 to 10): fluids return to the blood vessels, appetite and urine improve; a rash and itch may appear; tiredness may last for weeks.

Malaria: what it is

Malaria is caused by parasites carried by Anopheles mosquitoes, which bite mainly from dusk to dawn. It is found in many parts of India, particularly in forest areas, the north-east, Odisha, Chhattisgarh, Jharkhand, and in some cities where water collects.

Typical signs: fever with chills and shaking, followed by sweating, repeating in cycles in some types; headache, body ache, nausea, vomiting, weakness. In older adults, it can present as vague tiredness or confusion.

Severe malaria can cause confusion, drowsiness, fits, jaundice, breathlessness, dark urine, severe anaemia, very low blood sugar and kidney failure. It needs urgent hospital treatment.

Chikungunya and other fevers

Chikungunya causes high fever and severe joint pain, often lasting weeks to months. Typhoid, leptospirosis, influenza and urinary or chest infections can look similar; a doctor must examine and test. See monsoon illnesses and older adults: prevention.

When to get tested

Seek a doctor the same day if an older adult has fever (or feels unwell, even without fever) during or after the monsoon, particularly with: - Severe headache, body pain, pain behind the eyes. - Rash, bleeding or bruising. - Chills and shaking. - Persistent vomiting or abdominal pain. - Unusual drowsiness, confusion or weakness. - Known risk conditions, living alone, or recent travel to areas with malaria or dengue.

Tests the doctor may order include a dengue test (NS1 antigen in the early days, antibody tests later), a malaria test (rapid test or blood smear), blood counts (platelets, haematocrit), kidney and liver tests, and others. Do not rely on one test; discuss results with the doctor, and repeat testing if symptoms continue. Fever lasting more than two to three days, or any warning sign, needs medical review.

Caring for a parent at home (only when the doctor says it is safe)

Many mild cases are managed at home with close follow-up, but older adults with any warning sign, other illnesses, or who live alone are often better in hospital. Home care means:

• Follow the doctor's plan exactly, including follow-up blood counts, which are often repeated daily or every other day. - Rest in a cool, mosquito-free room under a net or screen, so that the person cannot infect mosquitoes that then bite others. - Fluids, fluids, fluids: small, frequent sips of water, oral rehydration solution, coconut water, soups, lemon-salt-sugar water, buttermilk and diluted juices, unless the doctor has restricted fluids for heart or kidney disease. Aim for pale urine. See diarrhoea and dehydration in seniors. - Light, easily digested food: khichdi, dal, rice, bananas, curd, porridge, soft fruits; see loss of appetite in older adults: causes and practical fixes. - Fever control: ask the doctor which fever medicine is safe and how much. Do not use anti-inflammatory painkillers or other blood-thinning pain relievers in suspected dengue unless the doctor specifically advises; they can increase bleeding. Use cool sponging as advised, and do not give extra tablets because the fever is "high". - No self-medication: avoid antibiotics, steroids, herbal juices or injections unless prescribed. Papaya leaf juice and similar remedies have no proven benefit and should not replace medical care or tests; discuss with the doctor if the family wishes to use them. - Monitor and record, at least four times a day: - Temperature; see digital thermometers: choosing and using them for older people. - Pulse, blood pressure and breathing; see how to measure blood pressure at home accurately. - Fluids taken and urine passed (how often, how much, colour). - Appetite, vomiting, abdominal pain, bleeding signs, bruises or rash. - Alertness and behaviour. - Oxygen saturation if advised; see pulse oximeters: how they work and how to use one. - Take extra care of other conditions: diabetes needs regular sugar checks; see how to test blood sugar at home. Take prescribed medicines as advised, with the doctor's guidance on any that may need adjustment. - Avoid injections into muscles and unnecessary procedures unless the doctor advises. - Prevent falls: weakness and dizziness are common; see falls risk assessment at home. - Do not leave an older adult alone during the critical phase. See monitoring an older adult during an acute illness at home.

Preventing infection

• Remove standing water around the house weekly: coolers, pots, bottles, buckets, flower vases, plant trays, tyres, tanks without lids.
• Use screens, nets and long clothes, and repellents as the label directs; ask the pharmacist about use in older skin.
• Daytime precautions for dengue and dusk-to-dawn precautions for malaria.
• Notify the local municipal or health authority about breeding sites.
• Protect the sick person under a net so mosquitoes do not carry the infection to others.
• Travel: ask the doctor about malaria prevention before travel to affected areas, and do not take any medicine for prevention without advice.

Recovery

Tiredness, low mood, body aches and poor appetite may last weeks after dengue, malaria or chikungunya; see slow recovery after infection in older adults. Rebuild with food, rest and gentle activity, keep follow-up visits and ask the doctor when it is safe to restart normal activity and any paused medicines.

Emergency signs: call 112 or go to hospital at once

• Persistent vomiting, severe abdominal pain, bleeding (gums, nose, vomit, black or bloody stools, heavy bruising).
• Confusion, drowsiness, difficulty waking, fits, unusual irritability.
• Cold, clammy, pale or bluish skin; weak, fast pulse; fainting or dizziness on sitting up.
• Little or no urine in six to eight hours.
• Difficulty breathing, rapid breathing, chest pain.
• Yellow eyes or skin, dark urine, severe weakness.
• Fever with stiff neck or severe headache.
• Inability to drink fluids.

When to ask a professional

Ask the doctor to test and examine any older adult with fever in the mosquito season, to plan monitoring and fluids, and to review all medicines. Ask a pharmacist before using repellents or any medicine. Seek urgent help for any of the emergency signs; see ambulance and emergency numbers in India.