[Current malaria situation in the Republic of Uzbekistan].

Malaria was once one of the most common diseases in Uzbekistan. There were massive epidemics with high mortality rates, wherein 140,000 to 700,000 cases of malaria were recorded. Following large-scale malaria control measures, the disease was eradicated in Uzbekistan in 1961 and the epidemiological situation is still favorable. The natural and climatic conditions that prevail in the Republic of Uzbekistan mean that the country is very susceptible to malaria. There are large water areas varying in type and origin, which provide a habitat for a number of epidemiologically dangerous species of malaria-transmitting mosquitoes in a single area. These are Anopheles maculipennis, An. pulcherrimus and An. superpictus. The prevailing temperatures promote rapid growth of vector mosquitoes and parasites and the malaria transmission season is over 5 months long. Seven malaria-transmitting mosquito species have been recently recorded in the Republic. DDT resistance has been so far noted in Anopheles maculipennis, An. hyrcanus and An. bifurcatus. An. superpictus is sensitive to all insecticides used in clinical practice (organophosphorus and organochlorine compounds, HOS, carbamates, pyrethroids). The most dangerous areas for transmitting malaria by importation are the flood plains of the country's main rivers, such as Syrdarya, Amudarya, Chirchik, Surkhana, etc., and rice-growing areas (an area of about 150,000 ha was under rice cultivation in 1999). The Republic is still very subjected to large-scale importations of malaria particularly in the towns and areas along the border with Tajikistan. There has been recently an increase in the incidence of infections imported into the Republic: 27 cases in 1995, 51 in 1996, 52 in 1997, 74 in 1998, and 78 in 1999. Eight regions of Uzbekistan border Tajikistan, their population is over 5.6 million people. In addition, close family ties between the populations of the frontier towns and regions further increase the risk for malaria to be imported and passed on. Noteworthy is the Surkhandaryin region that accounted for 60% of the cases recorded in 1999. The number of towns and villages where malaria occurs for the first time increased (49 and 46 cases in 1999 and 1998, respectively). The number of cases imported into rural areas also increased (70 (83%) cases in 1999 versus 48 (65%) cases in 1998); due to the large populations of malaria mosquitoes, there is a real danger that the disease may spread. In 1999, most cases of malaria were imported from Tajikistan (65 cases or 76% of all cases). There was a case from each of the following countries: Afghanistan, Pakistan, and Kazakhstan and 5 cases from Azerbaijan and Kyrgyzstan. The recorded cases included slighly more men than women (54% vs 46%). There were 10 infected children under 14 years, which was 23.5% of all notified cases. Analyzing various populations showed that 67.1% of the patients visited their relatives in malaria-endemic countries (mostly Tajikistan) and 25.8% migrated from Tajikistan. All the detected cases were confirmed by laboratory tests. As in the past, most cases were tertian (P. vivax) malaria (n = 82 or 96.4% of all cases). Tropical (P. falciparum) malaria was confirmed in 3 (3.5%) cases. These cases had been imported from Tajikistan into the Surkhandaryin region. Seventy seven (91%) cases were detected in the epidemical season. Of them 58 (68.2%) cases were detected during a malaria transmission season. Seven cases who contacted the patients with imported malaria and were infected were recorded in 1999. They included 4 and 3 cases in the Surkhandaryin and Kashkadaryin Regions, respectively. In 1999, there was a decline in the number of malaria patients who needed health care and in the diagnosed malaria cases in therapeutical and prophylactic institutions. Throughout the country, 34 (40%) of the 85 detected cases presented within 3 days of malaria outbreak (68.9% in 1998). Malaria was immediate diagnosed in 43.5% of cases (64.9% in 1998). The remaining cases were diagnosed as having acute respiratory viral infections, tropical and parasitic diseases, viral hepatitis, or influenza. Early diagnosis of malaria was made in 60% of cases (77% in 1998). Three cases of imported tertian malaria were recorded in the Tashkent Region in the first quarter of 2000. They were imported from Tajikistan into rural areas and the patients had been infected during the 1999 season. Epidemiological surveillance of malaria in Uzbekistan is regularly carried out by the general network of health facilities and by the departments of parasitology of state epidemiological surveillance centers in collaboration with medical administrative departments, the Ministry of Agriculture and Fisheries, the L.M. Isayev Research Institute of Medical Parasitology, and other agencies. Active links are maintained with WHO under the Roll Back Malaria programme. Great emphasis is laid on medical staff training at all levels. During the 1999 epidemiological survey, 672,536 laboratory tests were performed on blood samples from suspected malaria patients and individuals who had visited malaria-endemic countries, 55% of them suffering from fever. A total area of 17 million m2 of dwelling and nondwelling buildings 20 ha of water areas were treated against mosquitoes and the larvivorous fish Gambusia was put into the water areas occupying 6,500 ha. In all cases of malaria, the focus of infection was epidemiologically surveyed and required epidemic preventive measures were implemented. All malaria patients received a full course of radical therapy and recovered completely. The epidemiological surveillance system for malaria is affected by staff shortages at the parasitology departments of state epidemiological surveillance centers and by shortages of microscopes, reagents, sterilizing equipment, insecticides, etc. There are still difficulties in obtaining supplies of primaquine although a small stock is locally available as due to WHO humanitarian assistance. The Epidemiological Malaria Surveillance Programme for the Republic of Uzbekistan for 2000-2004, intended to strengthen the epidemic control capacity of health care facilities, Ministry of Health, is under adoption. The following activities are scheduled for 2000: to plan malaria control activities, including the zoning of the country by the risk of malaria transmission in accordance with republic-leveled directives, instructions, and methodology and WHO recommendations: adjustments to these plans to be made as necessary; to fill vacant posts in the parasitology departments of state epidemiological surveillance centers; to procure stocks of antimalarial drugs, reagents, insecticides, sterilizing equipment, etc., to be paid for from epidemiological service resources; to include malaria issues into certifying tests for physicians, as appropriate for the posts to be occupied and their level of qualifications; to publish posters, brochures, and leaflets about malaria prevention before the malaria transmission season for health education; to hold seminars and meetings for health workers on the etiology of malaria, its clinical features, diagnosis, treatment, and prevention.