Epidemiological Report
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KEELPNO_03.08.2012 HELLENIC CENTRE FOR DISEASE CONTROL AND PREVENTION Page | 1 MINISTRY OF HEALTH EPIDEMIOLOGICAL SURVEILLANCE REPORT MALARIA, 2012 (01/01/2012- 03/08/2012) Introduction Malaria is a parasitic infection, transmitted through the bite of the infected female Anopheles mosquito. Five types of plasmodia cause disease to humans: Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, Plasmodium malariae and Plasmodium knowlesi. The most common symptoms of malaria (chills, high fever, sweating, malaise, headache and muscle aches) manifest 1-4 weeks after infection with the parasite, while relapses of the disease are usually observed in short intervals but up to 5 and in extreme cases even up to 8 years after P. vivax infections. A number of effective anti-malarial drugs are available to treat the infection; starting the treatment promptly is essential in avoiding complications. Malaria is endemic in more than 100 countries around the world, mainly in sub-Saharan Africa and Asia. Greece was declared malaria-free in 1974, after an intense malaria eradication program between the years 1946-1960. Since then, approximately 30-50 cases are reported annually to the Hellenic CDC, the majority of which are travel-related. Sporadic malaria cases without reported travel history were recorded in 1991, 1999, 2000, 2009 and 2010. Epidemiologic surveillance data This data is derived from the reports of each laboratory-confirmed malaria case to the Hellenic CDC. The Department of Epidemiologic Surveillance and Intervention undertakes a verification procedure through communication with the treating physicians, the hospital and the National Reference Laboratory for Malaria in the Department of Parasitology and Tropical Diseases of the National School of Public Health. Single case investigation is undertaken by the staff of the Department of Epidemiologic Surveillance for malaria cases without reported travel history and for all malaria cases in Evrotas, Lakonia, where a cluster of malaria cases was detected in 2011. This involves communication with the patient and/or their relatives using a semi-structured questionnaire on possible risk factors for transmission and recording of detailed travel history for the last 5 years before the onset of symptoms. In addition, for the same cases the staff undertakes a focus investigation, which involves active case detection in an area of 100 meters around each case’s place of residence. All Greek residents are followed up for fever in weekly intervals for a total of one month and all immigrants are screened with one-round blood sample and then are also followed up for fever in weekly intervals again for a total of one month. Epidemiologic data, 2011 During the transmission period in 2011, a cluster of malaria cases with no history of travel to malaria- endemic areas was reported in the Municipality of Evrotas (Lakonia District) along with and sporadic cases KEELPNO_03.08.2012 in other Peripheral Districts (Evia, Larissa, Eastern Attica and Viotia) (Epidemiological Surveillance Report- Malaria in Greece, 2011). All of the cases were confirmed to have P. vivax infection by the Department of Parasitology and Tropical Diseases of the National School of Public Health. Specifically in Evrotas, Lakonia, 27 cases of malaria have been reported in Greek citizens without travel Page | 2 history in malaria-endemic regions and 7 cases in migrant farm workers from non-endemic countries (Morocco (1), Poland (1) and Romania (5 in total, 2 of whom were diagnosed in Romania). At the same time from this area there were another 23 reported malaria cases in migrant workers from malaria-endemic countries (Pakistan (21), Afghanistan (2)) with unclear travel history. Epidemiologic data, 2012 Since the beginning of 2012 up to 03/08/2012, 40 laboratory confirmed cases of malaria were reported overall in Greece, of which 33 are identified as imported (30 cases in migrants from malaria-endemic areas and 3 in returning Greek travelers). Of those, 24 cases are confirmed P. vivax infections. One case was diagnosed in a Moroccan migrant who resides in the Municipality of Evrotas (Lakonia District) with an unclear travel history, whose infection is considered to have occurred during the transmission period of 2011, and for this reason this case is not included in the analysis of this report. The remaining six (6) cases refer to Greek patients with no history of travel to a malaria endemic area with evidence that they have acquired the infection locally. The place of residence, nationality and transmission status of all the malaria cases reported to the Hellenic CDC until 03/08/2012 are presented in Table 1. The place of residence of the 6 locally acquired malaria cases without travel history is presented in Figure 1. Three (3) of those patients reside in the Municipality of Evrotas (Lakonia district), 2 in the Municipality of Marathon (East Attiki District) and one in Markopoulo (East Attiki District). All patients were confirmed to have Plasmodium vivax infection, by the Department of Parasitology and Tropical Diseases of the National School of Public Health. Figure 2 presents the distribution of the locally acquired malaria cases in Greece by week of reported onset of symptoms. Specifically in the Municipality of Evrotas, Lakonia from 01/01/2012 until 03/08/2012 a total of 10 malaria cases in migrant workers from malaria endemic countries (Pakistan (8), Afghanistan (2)), which are classified as imported (recent entry date to Greece and/or history of malaria in the past). The place of residence of the malaria cases in the Lakonia district is shown in Figure 3, while Figure 4 presents the distribution of the malaria cases in the same area by week of reported onset of symptoms. The age range of the Greek cases without history of travel to a malaria endemic country, is between 44 – 78 years (median age: 52 years), while 50% of the cases were male. KEELPNO_03.08.2012 Table 1. Place of residence, nationality and transmission status of malaria cases, Greece, 01.01.2012-03.08.2012 (n=39) Status of malaria cases District of Imported Locally acquired Residence Immigrants from Travelers from Total malaria endemic malaria endemic cases Page | 3 countries countries imported Lakonia 10 0 10 3 Attiki 10 2 12 3 Rethimno 2 0 2 0 Corfu 1 0 1 0 Thessaloniki 2 0 2 0 Viotia 1 0 1 0 Ioannina 2 0 2 0 Argolida 1 0 1 0 Aitoloakarnania 1 0 1 0 Larisa 0 1 1 0 KEELPNO_03.08.2012 Figure 1: Place of residence of the malaria cases without reported history of travel to malaria-endemic areas. Greece, 01/01 until 03/08/2012 (n=6). Page | 4 Attiki Lakonia Figure 2: Distribution of locally acquired malaria cases by week of reported onset of symptoms, Greece, 01/01 until 03/08/2012 (n=6). KEELPNO_03.08.2012 Page | 5 KEELPNO_03.08.2012 Figure 3. Place of residence of the malaria cases, Lakonia, Greece 01.01.2012 - 03.08.2012 (n=11) Page | 6 cases from malaria endemic countries cases of locally acquired malaria Figure 4. Distribution of malaria cases by week of reported onset of symptoms, Municipality of Evrotas, Lakonia, 01.01.2012 - 03.08.2012 *One case in a migrant from malaria endemic country, which was diagnosed in week 12/2012 is not included in the figure above. KEELPNO_03.08.2012 Discussion Greece has been malaria-free since 1974, but a number of significant factors may lead to the re- establishment of the disease, such as: Page | 7 (i) the large number of immigrants from malaria-endemic countries, who work mostly in the farming sector combined with (ii) the circulation of Anopheles mosquitoes, the competent vector of the disease, in many areas of Greece (iii) climate change and temperature increase, which contribute to increasing mosquito populations. All the above underline the need for a multi-sector control strategy, in order to manage malaria reintroduction and prevent its re-establishment in Greece. Among others this strategy should address intensifying mosquito control measures and vector research, communication to the public and health professionals to achieve early diagnosis and appropriate management of the disease. A Malaria Action Plan 2012-2015 was developed by the Hellenic CDC this year, which addresses all the above areas with the exception of vector control which belongs to the jurisdiction of the local governments. However, a number of reasons may lead to the detection of increased number of malaria cases in migrants this year, such as: - the ongoing active case finding supported by the Hellenic CDC and MSF-Greece, in the Municipality of Evrotas, Lakonia, - the focus investigations undertaken for each locally-acquired malaria case, - the screening of migrants undertaken in the Evros region (north border with Turkey), in Lakonia and also planned for other areas in Greece, - the increased awareness of health professionals around the country on the issue of re-emergence of malaria in Greece, after a campaign organized by the Hellenic CDC in the spring 2012. Early detection and appropriate treatment of malaria cases is one of the milestones to achieve effective control of the disease and prevent further transmission. Hellenic CDC activities for the management of malaria- 2012 During spring 2012 the Hellenic CDC developed an Action Plan for the Management of malaria 2012-2015, where the risk assessment for re-emergence of malaria in the different areas of Greece was included. Based on this risk assessment all areas (Regions, Municipalities) in Greece were assigned a risk level from 0-3, taking into consideration the malaria cases reported in the last three years, the size/place of origin of migrant population in the area and the ecological parameters in each area. The risk assessment is updated in regular intervals and depicted with the use of GIS. KEELPNO_03.08.2012 After the reporting of each locally-acquired malaria case to the Hellenic CDC a series of response activities are implemented: - Communication to the hierarchy of the Ministry of Health - Communication to the relevant regional department of public health Page | 8 - Communication to the National Centre for Blood Donation, responsible for the relevant blood safety measures.