Malaria in the US: With local cases in Florida, Texas, what to know about symptoms, treatment

A handful of malaria cases spread by mosquitos have been reported across the country in the last two months, marking the first time the disease has had a local spread in 20 years.

A public health alert warning was issued by the Centers for Disease Control and Prevention Monday to alert doctors, public health authorities, and the public about the risk.

Malaria is a serious disease transmitted through the bite of an infective female anopheline mosquito, according to the CDC. Although malaria can be fatal, the CDC said illness and death from the disease can usually be prevented.

Four cases were identified in southwest Florida and one in southern Texas, the Centers for Disease Control and Prevention said.

There is no evidence to support that the five cases might be connected, but public health authorities in both Florida and Texas are  monitoring local mosquito populations and surveilling their regions for other cases.

All five patients have since received treatment and are improving, according to the CDC.

As the weather gets hotter, especially in the spring and fall months, many regions will become more hospitable to mosquitoes as they thrive in warm and humid weather, according to a May 2023 report from the nonprofit climate science research organization Climate Central.

The more welcoming environment will allow the flying insects to arrive earlier and survive later into the year. A mosquito day is categorized by an average relative humidity of 42% or higher in addition to daily temperatures of 50 to 95 degrees.

More mosquitoes poses more opportunities for mosquitoes to bite people and potentially transmit disease, the report stated.

As you do your best to keep cool this summer, here’s everything you need to know and watch out for about surviving the slew of “mosquito days” we may have ahead.

A national warning: Malaria cases in Texas and Florida are the first US spread in 20 years, CDC says

How is malaria transmitted?

The short answer: a female mosquito that bites humans

Malaria is generally transmitted through an infective female mosquito called the Anopheles mosquito, according to the CDC.  After a mosquito bites an infected person, the microscopic malaria parasites and the mosquito's saliva have combined and are injected into next person when it looks for its next blood meal.

Is malaria contagious?

No. Malaria is not spread from person to person, and it cannot be sexually transmitted, according to the Centers for Disease Control. You cannot get malaria from casual contact with malaria-infected people.

Infected mothers can transmit parasites to their child during pregnancy before or during delivery.

While rare, transfusion-transmitted malaria does happen and when it does, it is a potential severe complication in blood recipients. On average, only one case of transfusion-transmitted malaria occurs in the United States every two years, the CDC said.

How can you avoid getting malaria?

Residents throughout Florida should take precautions by applying bug spray, avoiding areas with high mosquito populations, and wearing long pants and shirts when possible — especially during sunrise and sunset when mosquitos are most active.

What are the symptoms of malaria?

Symptoms of malaria include:

• Fever and flu-like illness, including shaking chills, sweats, headache, muscle aches, and tiredness.

• Nausea, vomiting, and diarrhea are possible.

• Malaria may cause anemia and jaundice (yellow coloring of the skin and eyes).

Anyone with symptoms of fever, chills, sweats, nausea/vomiting and headache should seek immediate medical attention, the Florida Health Department said.

More: Florida residents react to malaria cases

How soon could you feel sick after being bitten by infected mosquito?

There is a huge range on when you could feel any effects.

For most people, symptoms begin 10 days to four weeks after infection, although a person may feel ill as early as seven days or as late as one year later. Two kinds of malaria, P. vivax and P. ovale, can occur again, which is called relapsing malaria.

In P. vivax and P. ovale infections, some parasites can remain dormant in the liver for several months up to about four years after a person is bitten by an infected mosquito. When these parasites come out of hibernation and begin invading red blood cells, the person becomes sick.

How do you know if you have malaria?

The surest way to know whether you have malaria is to have a diagnostic test where a drop of blood is examined under the microscope for the presence of malaria parasites.

If you are sick and there is any suspicion of malaria, a test should be performed without delay, according to the Centers for Disease Control.

Is there a treatment if you have malaria?

Yes. Malaria can be cured with prescription drugs. The type of drugs and length of treatment depend on the type of malaria, where the person was infected, their age, whether they are pregnant, and how sick they are at the start of treatment.

The disease should be treated early in its course, before it becomes serious and life-threatening.

If you get malaria, do you have it for the rest of your life?

Not necessarily. In general, if you are correctly treated for malaria, the parasites are eliminated and you are no longer infected with malaria.

However, the disease can continue if it is not treated or if it is treated with the wrong drug. Some drugs are not effective because the parasite is resistant to them. Some people with malaria may be treated with the right drug, but at the wrong dose or for too short a period of time, the CDC said.

Two types (species) of parasites, Plasmodium vivax and P. ovale, have liver stages and can remain in the body for years without causing sickness. If not treated, these liver stages may reactivate and cause malaria attacks months or years later.

People diagnosed with P. vivax or P. ovale are often given a second drug to help prevent relapses.

How dangerous is malaria?

Malaria can very rapidly become a severe and life-threatening disease.

If not promptly treated, the infection can become severe and may cause kidney failure, seizures, mental confusion, coma, and death, according to the Centers for Disease Control.

Is there a malaria vaccine?

Attempts at producing an effective malaria vaccine and vaccine clinical trials are ongoing, the CDC said.

The malaria parasite is a complex organism with a complicated life cycle. The parasite has the ability to evade the body's immune system, making vaccine development difficult.

There are anti-malarial drugs available for use if you're traveling

Many effective antimalarial drugs are available. Your health-care provider will help you decide on the best drug for you, if any, based on your travel plans, medical history, age, drug allergies, pregnancy status, and other factors.

To allow enough time for some of the drugs to become effective and for a pharmacy to prepare any special doses of medicine (especially for children and infants), you may need to visit your health-care provider four to six weeks before travel.

Other malaria medicines only need to be started the day before travel and so last-minute travelers can still benefit from a visit to their health-care provider before traveling.

Malaria in people who are pregnant

Malaria in pregnant women can be more severe than in women who are not pregnant.

Malaria can increase the risk for serious pregnancy problems, including prematurity, miscarriage, and stillbirth.

Contributor: Anne Snabes

This article originally appeared on Sarasota Herald-Tribune: Malaria symptoms to know with US cases in Texas, Florida spreading