Malaria Outbreaks 2023

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September 8, 2023
Content Overview
Malaria is vaccine preventable disease caused by parasites transmitted by mosquitoes to people in 2023.

Malaria Outbreaks 2023

Malaria is a disease caused by four species of protozoan parasites of the genus Plasmodium: P. falciparum, P. vivax, P. malariae, and P. ovale and is transmitted to people by   Anopheles mosquitoes. Malaria-carrying mosquitoes can act as hosts to several microorganisms, including commensal bacterial species. According to the World Health Organization (WHO) World Malaria Report, the global number of malaria cases reached about 240 million, with over 600,000 related fatalities in 2021. The WHO has declared 42 countries malaria-free. On September 7, 2023, the Pan American Health Organization (PAHO), estimated that there are approximately 41 million people living in areas where the risk of infection by malaria is considered moderate to high, in 21 
Latin American countries. The PAHO also indicated that 19 countries and non-endemic territories in the Americas are currently considered free of malaria transmission. The Institute of Health Metrics and Evaluation publishes estimates of malaria deaths from 1990 onwards.

The U.S. Centers for Disease Control and Prevention (CDC) issued various outbreak alerts for malaria-endemic countries, including Costa Rica. The CDC published a Morbidity and Mortality Weekly Report on September 8, 2023, confirming eight cases of autochthonous malaria were reported by state health departments in Florida (seven) and Texas (one) from May 18–July 17, 2023. The CDC conducted a COCA Call on July 20, 2023 - Malaria Diagnosis and Treatment in the U.S. On June 26, 2023, the CDC issued Health Advisory CDCHAN-00494 regarding malaria cases in Florida and Texas. The CDC publishes Malaria Information and Prophylaxis by Country (2021). The CDC received reports of 1,823 confirmed malaria cases with the onset of symptoms in 2018, including one cryptic case and one case acquired through a bone marrow transplant. Though rare, Malaria can also be transmitted congenitally. Of imported malaria cases in the U.S., 59% were among persons who had traveled from Africa. The number of malaria cases reported in 2017 was the highest since 1972.

Current methods can vastly overestimate the rates of malaria parasites multiplying in an infected person's blood, which has important implications for determining how harmful they could be to a host, according to a new report. Some candidate malaria vaccines act during a stage in the parasite's life cycle when it replicates in the blood, so knowing its multiplication rates is critical to evaluating a vaccine's efficacy. Parasite multiplication rates (PMRs) are often quantified in malaria infections, wrote researchers in June 2023. They illustrated how inflated PMRs arise from two facets of malaria biology that are far from unique: (i) some developmental ages are easier to sample than others; (ii) the distribution of developmental ages changes throughout infection. The difficulty of accurately quantifying PMRs demonstrates a need for robust methods and a subsequent re-evaluation of what is known, even in the well-studied malaria system. "The inability to accurately measure those rates is concerning," said Megan Greischar, assistant professor of ecology and evolutionary biology in the College of Agriculture and Life Sciences and corresponding author.

A study published by the Royal Society on February 15, 2023, indicates these mosquitoes gained an average of 6.5 meters (21 feet) of elevation per year, and the southern limits of their ranges moved south of the equator by 4.7 kilometers (nearly 3 miles) per year.

Malaria Africa

The WHO says four African countries account for over 50% of all malaria deaths worldwide: Nigeria (31.3%), the Democratic Republic of the Congo (12.6%), the United Republic of Tanzania (4.1%), and Niger (3.9%). A study published by PLOS ONE on May 31, 2023, found 13 Sub-Saharan African countries' Malaria Indicator Surveys, the pooled prevalence of Malaria among children aged 6–59 months was found to be 27.41% (95% CI: 17.94%-36.88%) ranging from 5.04% in Senegal to 62.57% in Sierra Leone. On May 10, 2023, South Africa reported a significant increase in malaria cases in the endemic provinces and Gauteng. According to the 2022 World Malaria Report, Nigeria had the highest number of global malaria cases (27%) and the highest number of deaths (32%) in 2020. In addition, data from the 2018 Federal Republic of Nigeria Demographic and Health Survey show that malaria parasitemia in children was 23%.

Malaria The Americas

In the Region of the Americas, between 2022 and 2023, Argentina, Bahamas, Jamaica, and the U.S. reported sporadic cases of imported malaria and local transmission, including in areas where malaria cases had not previously been reported. Brazil and Venezuela reported the most malaria cases in 2022. Paraguay, Argentina, and El Salvador were certified malaria-free by WHO in 2018, 2019, and 2021, respectively. Additionally, Belize was certified malaria-free by WHO on June 21, 2023. The Costa Rica Health Surveillance Directorate of the Ministry of Health announced an increased risk of Malaria in Costa Rica, especially in coastal zones in 2023.

Malaria India

In 2022, 50 people died due to Malaria across India. However, this was a drastic decrease compared to 2014, when Malaria led to 562 deaths in the country. The National Framework for Malaria Elimination in India 2016-2030 was launched in 2016, followed by the National Strategic Plan 2017-2022. According to the WMR 2019, India represents 3% of the global malaria burden. 

Malaria United States

Florida, Maryland, and Texas have reported malaria cases in 2023. Seven locally-acquired and 35 travel-related malaria cases with onset in 2023 have been reported in Florida as of August 2023. Previously, the Florida Department of Health issued a statewide mosquito-borne illness alert on June 26, 2023. Sarasota and Manatee counties issued similar warnings on June 19, 2023. In 2003, 8 cases of locally acquired P. vivax malaria were identified in Palm Beach County, FL.

On June 23, 2023, the Texas Department of State Health Services (DSHS) reported one malaria case in Cameron County. These malaria cases have been identified as the P. vivax species of Malaria, which is not as fatal as other species. Effective treatment is readily available, and consultation advice is available for healthcare providers through the CDC Malaria Hotline (770-488-7788).

Malaria Vaccines 2023

Malaria vaccine information is posted at

Malaria Treatments

Malaria is curable with prompt diagnosis and treatment, preventing progression to more severe disease. Antimalarial therapies are approved in 2023.

Malaria Tests

As of August 2023, confidential malaria tests are offered by Ulta Labs

Malaria Outbreak News 2023

July 3, 2023 - "The (Gates) Foundation does not fund any work involving mosquito release in the United States," a spokesperson told AFP in an email. "Malaria eradication has been a top priority of our foundation for more than two decades, and we remain committed to devoting resources and expertise toward ending the disease for good."

June 28, 2023 - The journal Nature published an article: The next frontier for malaria vaccination.

June 26, 2023 - The Florida Department of Health issued a statewide mosquito-borne illness advisory following four confirmed and recovered local cases of locally acquired Malaria in Sarasota County.

April 13, 2023 - The U.S. Embassy in Costa Rica announced an increase in Malaria cases, primarily in the Caribbean province of Limon.

March 29, 2023 - The WHO announced that Azerbaijan and Tajikistan had been malaria-free.

February 22, 2023 - A Stanford University-led analysis could help forecast malaria outbreaks. Published in PLOS Global Public Health, this study could inform efforts to combat Malaria more efficiently and affordably.

February 20, 2023 - "South West Ethiopia is a newly constituted region characterized by weak physical infrastructure, recurrent and heavy floods, a fragile security situation, and poor public health awareness," explained Megi Wechuro, who heads South West Ethiopia's Public Health Institute.

January 24, 2023 - The Lancet reported results from a study in Benin, which confirms that adding the pyrrole insecticide chlorfenapyr to long-lasting insecticidal nets as a second active ingredient to back up the pyrethroids can have invaluable effects on malaria transmission and disease burden. 

December 14, 2022 - The Oaxaca (Mexico) Health Secretariat issued an epidemiological alert for an outbreak of Malaria. A total of 20 confirmed cases of Malaria have been identified.

December 8, 2022 - The WHO announced, "Following a marked increase in malaria cases and deaths in the first year of the COVID-19 pandemic, malaria-affected countries redoubled their efforts and were able to mitigate the worst impacts of Covid-related disruptions to malaria services" said Dr. Tedros Adhanom Ghebreyesus, WHO Director-General.

November 29, 2022 - The African country of Malawi expanded the malaria vaccine pilot to reach many more children in advance of its incorporation into its routine immunization program in 2023.