[Spread of tropical malaria in the Republic of Tajikistan (1994-2008)].

Tropical malaria occurred in the Republic of Tajikistan in 1994 after 40-year absence and spread in 28 regions of Tajikistan and in 3 cities (Dushanbe, Kulyab, and Kurgan-Tyube), peaking in 2000 (831 cases). A total of 3585 cases of tropical malaria were notified in 602 foci during a 15-year period. Migrants imported the pathogenic agent by the route of Pakistan-Afghanistan-Tajikistan during armed conflicts and in trading activities continually.The emergence of Asian Plasmodium falciparum phenotypes was accompanied by the clinical complications of the disease: the high percentage of moderate and severe forms of the disease was observed in preschool children in the absence of fatal outcomes. The rising incidence of malaria was associated with not only with the intensive import of the infection and the flight of infected malaria mosquitoes, but also with the active examination of the population during homestead rounds and with the timely laboratory diagnosis of malaria pathogens. The long-term goal antimalarial measures in the Republic of Tajikistan in 2009 resulted in the pause in the local transmission of tropical malaria, which meant its elimination in the country.

[Achievement of the elimination of tropical malaria in The Republic of Tajikistan].

To achieve the elimination of tropical malaria, Tajikistan divided its territory into districts in terms of the malariogenic potential (receptivity + vulnerability) and identified priority regions to be exposed, determined the population's fever background and the required personnel, equipment, and reagents for parasitological examinations, and compiled an inventory of malaria foci. The investigators tested a new (artesunate + sulfadoxine-pyrimethamine) treatment regimen in patients with tropical malaria and in parasite carriers and established active detection of malaria cases through homestead rounds and population examinations. The packages of antimalarial measures were improved, by annually evaluating their efficiency in accordance with the monitoring and estimation indicators.

[COMPLEX LABORATORY DIAGNOSIS OF MALARIA PATHOGENS IN THE PRE ELIMINATION PERIOD].

An immunological survey of 8,000 dwellers from 4 districts of Tajikistan failed to detect malaria pathogens by CareStartMalariaHPR2/PLDH (P. falciparum/P. vivax) COMBOGO161 AccessBio tests and showed the possibility of their further use under the Republic's conditions, particularly in the mountain villages and the human settlements bordering on Afghanistan. The results of examining 750 blood samples from the dwellers of sanitized foci in Tajikistan's areas, by applying molecular diagnosis via polymerase chain reaction, indicated no signs of parasites. A set ofthree methods, such as microscopic, immunological, and molecular diagnostic ones, was used to prove the absence of reliable malaria infection and local transmission sources.

[Evaluation of the efficiency of rapid tests in identifying malaria patients and parasite carriers in the Republic of Tajikistan].

The sensitivity of a rapid test versus microscopy ofblood samples was studied while examining 8000 dwellers from the republic's endemic areas. The results of blood testing in the Kumsangir, Dangara, and Vakhdat districts showed agreement with those of blood microscopy. The result of rapid tests did not agree to that of blood microscopy only in one case in the Kabadiyan District. The findings suggest that tests (Care Start b Malaria HPR2/PLDH 2 line test (P.falciparum/P.vivax) COMBO GO161 Access Bio, Inc.) are rather effective and may be further used particularly in remote and Afghanistan-adjacent settlements, as well as among border-guards, in blood transfusion centers and emergency units.

[The specific features of the epidemiology of tertian (Plasmodium vivax) malaria in the Republic of Tajikistan].

The specific features of the functioning of parasitic systems of tertian malaria were found in the elimination period when the number of foci and patients were drastically reduced. Despite the sporadic cases of tertian malaria, in 2009-2012 each of the 9 areas of the Kurgan Tyubin zone, Khatlon Region notified 12 of the 43 active foci with single manifestations of malaria after a long incubation period in the following spring or March-April a year later. The results of these investigations should be borne in mind when planning and implementing antimalarial measures.

[Malaria mosquitoes (Diptera, Culicidae, Anopheles) of North Tajikistan, their ecology, and role in the transmission of malaria pathogens].

Five species of malaria mosquitoes: An. artemievi, An. claviger, An. hyrcanus, An. superpictus, and An. pulcherrimus were found in North Tajikistan in 2006 - 2007. Species affiliation was identified according to the morphological signs of their larvae and imagoes, and by using the polymerase chain reaction-restriction fragment length polymorphism analysis. There was a larger number of An. hyrcanus (34%), An. artemievi (29%), and An. pulcherrimus (24%) and a smaller number of An. superpictus (11%); and An. claviger was few (2%). The hatching sites of the above species and the preferred types of their day refuges were found. The intensity of attack of different Anopheles species on humans and animals was studied. Among the North Tajikistan malaria mosquitoes, An. pulcherrimus and An. superpictus are of the greatest epidemiological importance as vehicles for transmission of malaria pathogens. An. artemievi and An. hyrcanus are minor vehicles. At present, An. claviger is of no epidemiological significance in transmitting malaria in North Tajikistan.

[Evaluation of the prevalence of helminthiasis among the population of the Republic of Tajikistan].

Helminthological examinations of 2629 persons of different ages have shown that the prevalence rate of soil-transmitted helminths averages 54.24% of the examinees. There isa high rate of helminthiasis in the examined dwellers from two districts (Vanch and Faizobod) in the foothill and mountain zones (78.23% and 67.5%, respectively) and its low rate in the Murgab district in the high-altitude area. The non-observance of personal hygiene and sanitary standards and the use of water from open contamination-unprotected water sources contribute to intensive invasion of the population with helminthes.

[Evaluation of the efficiency of rapid tests to detect malaria patients and parasite carriers in Tajikistan].

The sensitivity of a rapid test versus microscopy of blood samples was studied while examining 7983 dwellers from the republic's endemic areas. The results of blood testing in the Pyanj and Shurobod districts showed agreement with those of blood microscopy. However, its sensitivity in two other districts was as high as 1.9%. Only one of 53 positive tests was verified by microscopy examination. The findings suggest that it is impossible to use the examined tests (Access Bio Inc. Care Start Malaria pLDH 2 line test) under the conditions of Tajikistan; all the more they identify malaria without differentiation in its pathogen types.

[Malaria in Tadjikistan: from control to elimination].

In the past three years, a notable progress has been made in the control of malaria, as suggested by a drastic reduction in malaria morbidity and in the number of active foci. To fulfill the set tasks, there is a need for continuous financing of antimalaria measures by the country's Government, the Global Fund, WHO, and other sponsors. In the Republic of Tadjikistan, there are prerequisites for achieving the elimination of tropical malaria by 2010; however, it is necessary to collaborate with the Islamic State of Afghanistan for prophylactic measures to be implemented to prevent importation of tropical malaria from the boundary areas.

[The epidemiological and clinical characteristics of malaria under the present conditions of Tajikistan].

The highest malaria morbidity rates have been observed in the Tajikistan's Khatlon Region that is contiguous with Afghanistan. This area is notorious for its high malariogenicity ("susceptibility" according to the WHO terminology), caused by natural climatic factors, as well as a significant vulnerability associated with socioeconomic conditions (intensive migration of populations among which there are many infected subjects). In children, tropical malaria is generally characterized by an acute onset, abnormal fever, and its polymorphism of clinical manifestations that are exemplified by the lack of typical malaria paroxysms, as well as a gradual progression of parasitemia during the first malaria attacks. Recurrences are induced by ineffective treatment and chloroquine resistance in the tropical malaria pathogen. The reduction in malaria morbidity has resulted from a package of large-scale malaria-controlling measures implemented with the support of the Global Fund to Fight AIDS, Tuberculosis, and Malaria.

[The current malaria situation in Tadjikistan].

Malaria-controlling measures and the population's chemoprevention in the intensive foci caused a drastic morbidity reduction in the republic, by showing a 1.5-fold decrease in the number of malaria cases in 2005 as compared with the previous year (2309 versus 3577). Malaria patients are notified in the republic throughout the year, but infection transmission occurs in June to October. Eleven species ofAnopheles mosquitoes have been currently known in Tadjikistan; only three of them (An. superpictus, An. pulcherrimus, and An. maculipennis) are effective vectors. Malaria mostly affects the Khatlon Region (a total of 2039 cases, including 76 cases of tropic malaria) that is a valley-desert landscape in the south of Tadjikistan. In the 2006 spring, mass preventive treatment with primaquine was performed in 10 districts of the Khatlon Region, covering 98694 persons. In August 2006, the houses were treated with the insecticides Alfacipermetrine and Triton in 34 towns and districts of the republic; 25145 permetrine-impregnated bed curtains were distributed in 7 districts to protect the population from mosquito bites. In 8 districts, topminnows (Gambusia) were let into the Anopheles mosquito-rich water reservoirs and rice-growing fields with a total area of 680 ha.

[Supplement to the list of Anopheles (Diptera, Culicidae) mosquitoes of Tadjikistan and the predominant types of vectors in the current foci of malaria in the republic]. / Dopolnenie k spisku komarov roda Anopheles (Diptera, Culicidae) Tadzhikistana i dominiruiushchie vidy perenoschikov v sovremennykh ochagakh malarii v respublike.

The species composition of and the indices of predominance of Anopheles mosquitoes were determined in the current foci of malaria in the Republic of Tadjikistan. The predominant types of malaria mosquitoes were An. superpictus, An. pulcherrimus, and An. hypcanus were found to be in the Khatlon Region of Tadjikistan and in the contiguous areas of Uzbekistan. An. superpictus prevailed in the study foci of malaria and, as An. pulcherrimus, were the most dangerous vectors of malaria in the south of the republic. The main vectors of malaria were shown to be An. maculipennis sensu stricto and An. superpictus in the environs of the town of Khudjand, Sogdi Region (Tadjikistan). An. maculipennis was first recorded for Tadjikistan and should be included into the list of malaria mosquitoes of the republic. It is suggested that An. pulcherrimus plays an important role in the spread of malaria in the north of Tadjikistan.