Abstract & Commentary

New Malaria Recommendations for Greece — October, 2011

By Mary-Louise Scully, MD, FAAP, Director, Travel and Tropical Medicine Center, Sansum Clinic, Santa Barbara, CA

Dr. Scully reports no financial relationship to this field of study. This article originally appeared in the December 2011 issue of Travel Medicine Advisor. At that time it was peer reviewed by Lin H. Chen, MD, Assistant Clinical Professor, Harvard Medical School; Director, Travel Medicine Center, Mt. Auburn Hospital, Cambridge, MA.

Dr. Chen has received research grants from the Centers for Disease Control and Prevention and Xcellerex.

Synopsis: Due to ongoing evidence for malaria transmission in the Laconia (Lakonia) district of Greece, the Centers for Disease Control and Prevention (CDC) is now recommending that travelers to this area take anti-malarial chemoprophylaxis. The enhanced use of personal protection measures against mosquito bites in this and other agricultural areas of Greece is also recommended.

Source: CDC Alert. New Malaria Recommendations for Greece. Available at: www.cdc.gov/malaria/malariagreece.htm. Accessed Nov. 5, 2011.

Greek health authorities recently published findings of 36 cases of Plasmodium vivax malaria in Greece occurring between May 2011 and September 2011.1 Twenty of these malaria cases had no travel history outside of Greece and the remaining 16 cases were in persons from malaria-endemic countries where local transmission vs. importation could not be determined (migrant cases). The majority of all the cases occurred in the southern agricultural area of Evrotas, Laconia. Other areas included the Evia/Euboea (island east of Central Greece region), Eastern Attiki, Viotia, and Larissa districts (see map, below). All 36 cases were confirmed as P. vivax by both PCR and microscopy identification.

The median age of reported cases was 36 years, but the median age in migrant cases was lower (24 years) and migrant cases were all male. All cases were hospitalized, treated, and recovered except for one fatality in a patient with underlying cardiac and pulmonary disease who developed acute respiratory distress syndrome. Most were treated with a 3-day course of chloroquine followed by a 14-day course of primaquine. Only one case had glucose-6-phosphate dehydrogenase (G6PD) deficiency and, therefore, did not receive primaquine.

The Laconia (Lakonia) district is an agricultural plain that lies in the delta region of the Evrotas River. The authors note that this area has fresh-water springs, irrigation and drainage channels, and coastal wetlands that provide ideal breeding grounds for the 15 species of Anopheles mosquitoes found in Greece, of which five species are considered to be potential malaria vectors. Anopheles sacharovi and Anopheles claviger were the most commonly identified species in the areas of outbreaks.

In the Evrotas area, it is estimated that migrant farm workers make up 2,000-4,000 of the total population of 4,485 depending on the time of year. Approximately 80% of migrant workers in this area are from Pakistan, about 15% from Romania, and the remaining are from Morocco. In the other outbreak areas of Greece there were also high numbers of migrant workers from malaria-endemic countries, especially the Indian subcontinent. These areas of Greece are not typically visited by tourists.

In light of the ongoing malaria transmission in the Laconia district of Greece, the U.S. CDC now recommends that travelers to this destination take malaria chemoprophylaxis. Appropriate anti-malarials (U.S. CDC) include atovaquone-proguanil (Malarone®), chloroquine, doxycycline, mefloquine, or primaquine. Primaquine use requires prior testing for G6PD deficiency.

Commentary

Malaria was eradicated from Greece in 1974, though occasional sporadic cases of local mosquito-borne transmission have occurred throughout the years. This outbreak is unique both in the number of cases and the sustained transmission that is ongoing. The combination of ideal climate, close proximity of human and mosquito populations, and increasing numbers of migrant workers from malaria-endemic countries are contributing to the outbreak.

Table Distribution of malaria cases in Greece

All the cases were secondary to P. vivax, for which full treatment requires presumptive anti-relapse therapy (PART) with primaquine to eradicate the hypnozoite forms that remain dormant in the liver. The dose is 30 mg/day for 14 days. Primaquine is contraindicated in persons with G6PD deficiency and pregnant females, so testing is necessary before its use. The most prevalent G6PD variants are G6PD A- and G6PD Mediterranean. These variants can result in severe hemolysis by the sudden destruction of older, more enzyme-deficient red blood cells after exposure to drugs like primaquine, nitrofurantoin, sulfamethoxasole, or foods such as fava beans.2

In addition to the recommended use of anti-malarials in travelers to the Laconia district of Greece, clinicians globally should be aware of this outbreak and include malaria in the possible differential diagnosis of any febrile patient returning after travel to Greece.

References

  1. Danis K, et al. Autochthonous Plasmodium vivax malaria in Greece, 2011. Euro Surveill 2011;6(42). Available at: www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19993.
  2. G6PD Deficiency Favism Association. Available at: http://www.g6pd.org/favism/English/index.mvc. Accessed Nov. 5, 2011.