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Published Date: 2011-09-03 12:26:17
Subject: PRO/EDR> Malaria, P. vivax - Greece (03): autochthonous
Archive Number: 20110903.2692

MALARIA, P. VIVAX - GREECE (03): AUTOCHTHONOUS
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Date: Fri 2 Sep 2011
Source: Eurosurveillance 2011;16(35): 1 Sep 2011
http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19954

_Plasmodium vivax_ malaria in a Romanian traveler returning from
Greece, Aug 2011
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In August 2011, a _Plasmodium vivax_ malaria infection was diagnosed
in a Romanian traveller returning from Greece. This case together with
several reports over the past decade of autochthonous cases in Greece
highlight that malaria should be considered as differential diagnosis
in symptomatic travellers returning from this country. Travellers may
serve as sentinels of emerging vectorborne diseases.

Malaria is considered to be eradicated in several European countries
since 1975, although _Anopheles_ spp. mosquito vectors remain
prevalent in parts of southern and central Europe [1]. A few cases of
autochthonous transmission of malaria to local residents have been
reported over the last 10 years in areas where the disease has been
declared eradicated (Bulgaria, France, Germany, Greece, Italy, and
Spain), including the so-called airport malaria, but there has not
been sustained local transmission in any specific location [2].

In this report, we describe a case of malaria in a Romanian traveller
returning from Greece.

Case report
-----------
On 1 Aug 2011, a 25 year old Romanian man developed an acute febrile
illness with chills, myalgia, fever, and left abdominal flank pain. He
had returned from Greece on 30 Jul 2011. His past medical history
included a splenectomy 14 years earlier. As the symptoms persisted, on
3 Aug 2011, the patient visited the family doctor who suspected a
respiratory infection and prescribed a symptomatic and antibiotic
treatment (amoxicillin-clavulanate). On 9 Aug 2011, as there was no
improvement in his symptoms, as the fever persisted and he felt an
increased pain in the left flank, and after an episode of near
syncope, he was admitted to the local hospital in his area of
residence.

Abdominal ultrasound showed a hematoma in the splenic bed (5.5 by 6.6
cm). The hematoma was surgically drained. On 11 Aug 2011 laboratory
results revealed thrombocytopenia (57 000/mm3; norm: 150 000-400 000),
anaemia (Hb: 8.7 g/dl; norm 11.5-15), and leukocytosis (16 600/mm3;
norm: 4000-10 000) with normal white blood cell differential count.
Blood cultures taken upon each hospital admission remained negative.
Thin blood smear revealed _Plasmodium_ spp. trophozoites and
schizonts. On the same day, the patient was transferred to Victor
Babes Hospital for Infectious and Tropical Diseases in Bucharest. On
arrival, physical examination revealed a reduced general condition, a
temperature of 37.8 deg C [100 deg F], abdomen with diffuse
sensitivity to palpation, and moderate hepatomegaly. Thin and thick
films revealed _Plasmodium vivax_ parasitaemia of 0.05 per cent with
mature trophozoites, young schizonts, and gametocytes of _P. vivax_.
Whole blood DNA quantification using a LightScanner 32 (Idaho
Technology, USA) demonstrated _P. vivax_ (1500 copies/mul) and was
negative for the other _Plasmodium_ species.

The patient responded quickly to the 7-day treatment of oral quinine
combined with doxycycline. The clinical response was good (fever
ceased after 48 hours of treatment) and the parasite clearance
appropriate (negative thin and thick smear after 72 hours of
antiparasitic treatment). After this treatment, the patient was given
primaquine for 14 days to prevent relapses. Patient history revealed
that he had worked intermittently in agriculture in Greece, for about
6 years (in 2005 in Argos region and then every October to February
from 2006 to 2010 in Lakonia region, in Skala and Elos localities of
the Evrotas river basin). More recently, from November 2010 to 30 July
2011 he worked in the same regions (Skala and Elos) in agriculture. He
had no history of travel to any malaria-endemic areas and his only
other travel abroad was a 2-month trip to Italy (Sicily) from
September to October 2010. He had never travelled by plane, he does
not live in the proximity of any international airport and there have
been no reports of imported malaria cases within his residence area in
Romania. Malaria tests in the patient's relatives with whom he had
travelled and worked in Greece were negative.

Epidemiological situation in Greece
-----------------------------------
Several anopheline vector species are known to breed in Greece,
including some of the historically most important vectors in Europe
including _A. atroparvus_, _A. sacharovi_, and _A. superpictus_ that
are competent for _P. vivax_ [3]. As early as 1994 and 1995 4
autochthonous malaria cases (_P. falciparum_, _P. malariae_, and 2 _P.
vivax_) were diagnosed in Evros, northern Greece, in native residents
from rural areas who stated that they had never left Greece or visited
an international airport [4]. In the summer of 1998 2 additional
malaria cases (_P. vivax_) were diagnosed in the same region in 2
patients who had been living for 4 years in Feres (in the Evros
peripheral area, East Macedonia and Thrace, Greece) after they had
immigrated from southern Albania [5]. Later, an autochthonous cluster
of _P. vivax_malaria occurred in the Evrotas river basin, Lakonia,
southern Greece, from August to October 2009, with 8 patients
hospitalised in Sparta General Hospital, including 2 immigrants from
Pakistan and Afghanistan and 6 patients, natives of Lakonia and living
in different areas from the 1st 2 [6]. More recently, between June and
18 Aug 2011, 6 cases of locally-acquired _P. vivax_ malaria have been
notified to the Hellenic Centre for Disease Control and Prevention
through the mandatory notification system in Greece: 4 cases from the
same agricultural wetland area of the Evrotas river basin, Lakonia, in
the Peloponnese, southern Greece and 2 cases who reside near the city
of Chalkida, Evoia, in the eastern part of Greece [7]. All cases were
local residents with no history of travel to a malaria endemic area.

Epidemiological situation in Romania
------------------------------------
The _P. vivax_ malaria case in Romania was reported to the National
Institute of Public Health within the National Malaria Surveillance
Programme. In Romania, there is a national programme for surveillance
and rapid communication of malaria cases. In 1948, a total of 333 198
cases of malaria were reported, but starting with 1968 Romania was
declared a malaria-free country. No local transmission of malaria has
been reported in Romania since then. Nevertheless, malaria remains a
possible re-emerging disease especially in the southern and
south-eastern part of the country, where vector-competent Anopheles
species are prevalent [8]. In the past 10 years, 107 cases of malaria
were diagnosed in the Victor Babes Hospital of Infectious and Tropical
Diseases in Bucharest and all of them were in travellers who had
returned from malaria endemic areas, mostly from Africa [9,10].

Discussion and conclusions
--------------------------
The occurrence of presumably vector-competent Anopheles species,
together with increasingly favourable climatic conditions and the
frequent availability of reservoirs of infection such as imported
cases, produce an ongoing probability of autochthonous malaria
appearing time and again. This case report presented epidemiological
evidence and patient history point to an infection in the Skala and
Elos areas Greece. Prior to 2011, the patient had not been exposed in
Greece during summer, or during periods when autochthonous cases were
reported in Greece. However, it is unclear whether the reservoir of
infection for this case was from migrant workers in Greece coming from
South Asia or from the local population.

To the best of our knowledge, this is the 2nd case of malaria reported
recently in an international traveller who acquired the infection in
an European Union (EU) country. In 2000, a German couple was diagnosed
almost simultaneously with _P. vivax_ malaria after a one-week holiday
in Kassandra, Chalkidiki, a Greek tourist resort [11]. No local cases
had been reported at that time but it seems that sporadic local
transmission must have been occurring. Since Greece is a frequent
destination for people visiting or working, any re-emergence of
malaria will be of concern. Furthermore, the occurrence of malaria
cases in areas considered to be malaria-free may lead to delay in
diagnosis raising the possibility of exposure to vectors and even the
risk of incidence of local malaria cases.

To date, there has been no recommendation for travellers to the
affected areas in Greece to take any anti-malarial chemoprophylactic
drug. However, advice has been issued on avoidance measures regarding
insect bites particularly during the evening and at night [12,13]. In
the authors' opinion, the Greek interventions with the current cases
should be followed closely so that Romania and other formerly malaria
endemic countries in the EU remain malaria-free. Both local health
authorities and practicing clinicians need to be aware that they
should also include malaria in the differential diagnosis in
travellers and temporary residents returning from Greece and maybe
also other southern European countries. However, according to a risk
assessment related to the 6 autochthonous cases of _P. vivax_ malaria
in Greece, published by the European Centre for Disease Prevention and
Control, the risk for further extension of malaria transmission into
the EU is considered low at present [7].

Acknowledgements
----------------
We are grateful to Prof David O Freedman from GeoSentinel and Eskild
Petersen for helpful discussions.

References
----------
See the URL above.

--
communicated by:
Florescu SA, Popescu CP, Calistru P, Ceausu E, Nica M, Toderan A, et
al [see URL above for affiliations]

[The report nicely summarizes autochthonous malaria cases in Greece
over the past 15 years. The number of cases are small with several
years apart and in different locations (Evros, 1994-5; East Macedonia
and Thrace 1998; Lakonia 2009; Lakonia and Chalkida, Evoia 2011),
pointing to asymptomatic gametocyte carriers as the source.

A sustained reservoir in Greece would require a certain number of
cases each year in the same region. The population are not immune so
cases are likely to be clinical and should be picked up by the local
health care system. The reporting of the cases this summer show that
new malaria cases will identified by the Greek surveillance system, so
unreported cases are unlikely.

The areas where the cases were reported from are agricultural areas
and the most likely explanation is migrant labor from endemic areas
being asymptomatic gametocyte carriers. These agricultural areas often
grow vegetables in greenhouses and the production is labor intensive.

The local vectors are able to transmit malaria and thus a small number
of infections are seen from these asymptomatic carriers, but there is
no sustained reservoir.

It would be interesting to have data on imported migrant labor --
legal and illegal -- in the areas reporting cases. It is likely that
there are migrant laborers from malaria endemic areas.

HealthMap location: http://healthmap.org/r/1cZu. - Mod.EP]

See Also