The Centers for Disease Control (CDC) announced on Oct. 31 that it had finalized the number of malaria cases diagnosed in the United States in 2011. The data showed that the 1,925 cases diagnosed were the greatest number found in the country since 1971. Nearly all the cases of malaria were contracted outside the U.S. and are termed “imported” by public health authorities.
The CDC may take as long as two years to finalize the data for notifiable illnesses and conditions. The Dec. 29, 2012 count of malaria cases for 2011 was 1,724. In the ten months since that report was issued, the CDC discovered an additional 201 cases. While the 2011 count released yesterday was a modern record for the U.S., the nation sees over 1,000 cases yearly routinely.
As of week 43 of 2013, ending Oct. 26, the latest CDC data shows 1,045 malaria cases year to date. The report from Dec. 29, 2012 shows 1,164 malaria cases in that year. Both numbers are considered preliminary by the CDC, pending a review, and will not be finalized for some time.
New York State reports the greatest number of malaria cases in most years. For 2012, the state, including New York City, reported 232 cases. This year, through week 43, the state has reported 208. New York City reports, in general, 80 to 85 percent of all those cases, with the remainder found in New York counties outside of NYC.
The New York Times reports that just five of the 1,925 malaria cases in 2011 were acquired in the United States. Two were in infants born to mothers with the illness. One was a laboratory accident. One came through a transfusion and the last was in a patient whose travel history may have been incomplete.Five deaths resulted from the 2011 infections.
The 1,900 malaria cases imported into the United States in 2011 were primarily acquired in Africa, 69 percent of all cases. Of those cases, 63 percent of the illnesses were caught in West Africa. Among individual countries, India was the source of the most imported malaria cases.
The CDC describes malaria in its press announcement this way:
“Malaria is caused by a parasite transmitted by the bite of an infective female Anopheles mosquito. In 2010, it caused an estimated 660,000 deaths and 219 million cases globally.“
The genus Anopheles mosquito is the only carrier of the parasite that causes malaria in humans. Some 30 to 40 of the 430 Anopheles species are known to transmit the illness. At least three of these species are commonly found in the United States and malaria outbreaks occurred until the illness was declared eradicated in the country in 1951. The mosquitoes remained.