Recent successes in malaria control have put malaria eradication back on the public health agenda. A significant obstacle to malaria elimination in Asia is the large burden of Plasmodium vivax, which is more difficult to eliminate than Plasmodium falciparum. Persistent P. vivax liver stages can be eliminated only by radical treatment with a ≥ seven-day course of an 8-aminoquinoline, with the attendant risk of acute haemolytic anaemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Primaquine is the only generally available 8-aminoquinoline. Testing for G6PD deficiency is not widely available, and so whilst it is widely recommended, primaquine is often not prescribed. In the past, some countries aiming for vivax malaria eradication deployed mass treatments with primaquine on a massive scale, without G6PD testing. In Azerbaijan, Tajikistan (formerly USSR), North Afghanistan and DPR Korea 8,270,185 people received either a 14-day “standard” or a 17-day “interrupted” primaquine treatment to control post-eradication malaria epidemics. These mass primaquine preventive treatment campaigns were conducted by dedicated teams who administered the drugs under supervision and then monitored the population for adverse events. Despite estimated G6PD prevalences up to 38.7%, the reported frequency of severe adverse events related to primaquine was very low. This experience shows that with careful planning and implementation of mass treatment strategies using primaquine and adequate medical support to manage haemolytic toxicity, it is possible to achieve high population coverage, substantially reduce malaria transmission, and manage the risk of severe acute haemolytic anaemia in communities with a relatively high prevalence of G6PD deficiency safely.

The epidemiological situation in Tajikistan Republic deteriorated in the 1990s, when an influx of refugees from Afghanistan resulted in mass importation of Plasmodium vivax and Plasmodium falciparum malaria to Khatlon region. The National Programme of Malaria Control was successful and malaria transmission was interrupted in 2009. Background. The aim of this study was to investigate the mechanisms of immunological response in Tajik children with tropical Plasmodium falciparum malaria. Materials and Methods. We examined 124 patients with P. falciparum malaria at the age of 6 months up to 14 years that were hospitalized in Clinical Infectious Diseases Hospital in Dushanbe city and in Regional hospital of Khatlon region in the period 2000-2007. In most cases, they were school-age children (56%). The peak incidence was recorded in July-October. Verification of the diagnosis was based on clinical, epidemiological data, and the results of blood microscopy. In all patients, along with the standard, clinical, and laboratory tests, a number of indicators of the immune status were performed that include the T-immunity, the content of serum immunoglobulins of three main classes, the level of circulating immune complexes (CIC), C3 complement, and the concentration of key serum cytokines that have been studied in the dynamics of infectious process. Finding. The study of cellular and humoral immunity in patients with Plasmodium falciparum malaria is an obvious additional criterion in assessing the severity of infection. The imbalance of cytokine profile is an important pathogenic factor in the development of severe and recurrent forms of the disease, since the formation of a defective immune response to parasitic antigens contributes to adverse outcomes. Conclusions. Plasmodium falciparum malaria was characterized by depression of cellular and humoral immunity, the degree of which depended on the severity of the pathological process.

Background. Imported cases of Plasmodium vivax malaria from western Africa are reported annually in the Russian Federation. Infected native African people moving from western Africa for different purposes (students, businessmen, specialists, etc.) or Russian citizens (tourists, diplomats, businessmen, etc.) incubate the pathogen until reaching their Russian destination. Methods. All imported and other confirmed malaria cases and the associated Plasmodium species recorded over the past twenty years throughout the Russian Federation were inventoried. These data were included in the national register. The data of imported malaria cases were analysed according to the species of Plasmodium, case origin, dates of importation, and patient nationality. Results. A total of 267 P. vivax-infected patients who contracted the disease in western Africa were diagnosed in the Russian Federation from 1984 to 2017. Among them, 3 cases had mixed infections (2 with P. vivax + P. falciparum and 1 P. vivax + P. ovale). Conclusion. Our data reveal an existing risk of contracting P. vivax infections in towns of West sub-Saharan Africa despite the absence of local P. vivax infection records.

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Malaria was eliminated in Tajikistan by the beginning of the 1960s. However, sporadic introduced cases of malaria occurred subsequently probably as a result of transmission from infected mosquito Anopheles flying over river the Punj from the border areas of Afghanistan. During the 1970s and 1980s local outbreaks of malaria were reported in the southern districts bordering Afghanistan. The malaria situation dramatically changed during the 1990s following armed conflict and civil unrest in the newly independent Tajikistan, which paralyzed health services including the malaria control activities and a large-scale malaria epidemic occurred with more than 400,000 malaria cases. The malaria epidemic was contained by 1999 as a result of considerable financial input from the Government and the international community. Although Plasmodium falciparum constituted only about 5% of total malaria cases, reduction of its incidence was slower than that of Plasmodium vivax. To prevent increase in P. falciparum malaria both in terms of incidence and territory, a P. falciparum elimination programme in the Republic was launched in 200, jointly supported by the Government and the Global Fund for control of AIDS, tuberculosis and malaria. The main activities included the use of pyrethroids for the IRS with determined periodicity, deployment of mosquito nets, impregnated with insecticides, use of larvivorous fishes as a biological larvicide, implementation of small-scale environmental management, and use of personal protection methods by population under malaria risk. The malaria surveillance system was strengthened by the use of ACD, PCD, RCD and selective use of mass blood surveys. All detected cases were timely epidemiologically investigated and treated based on the results of laboratory diagnosis. As a result, by 2009, P. falciparum malaria was eliminated from all of Tajikistan, one year ahead of the originally targeted date. Elimination of P. falciparum also contributed towards speedy reduction of P. vivax incidence in Tajikistan.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-017-1861-5) contains supplementary material, which is available to authorized users.