Spread of salmonellosis in Moscow and the ways of its prophylaxis

The article deals with the results of the epidemiological analysis of the spread of salmonellosis in Moscow. During the last 15 years the proportion of Salmonella enteritidis was about 80% and more. After salmonellosis morbidity decreased to 19.9 per 100,000 of the population (the minimum level) in 1985 its sharp rise was noted. Morbidity rate increased from 31.7 in 1987 to 55.1 per 100,000 in 1988, then to 93.9 per 100,000 of the population in 1989 (the maximum level). In the subsequent years up to 1996 a decrease in morbidity rate was observed, but in 1997-2002 morbidity rate stabilized within 29.8-35.7 per 100,000 of the population without a perceptible tendency towards decrease. The sharp increase of the etiological role of S. enteritidis which led to a wide spread of Salmonella infections was caused by the "chicken-egg" factor of their transmission. High morbidity rate among children and adults, registered all the year round, is the consequence of the constant epidemic activity of this factor.     

Environmental Manganese and Cancer Mortality Rates by County in North Carolina: An Ecological Study

Manganese is an element essential for health in trace amounts, but toxic at higher exposures. Since manganese is replacing lead in gasoline globally, evaluation of potential cancer effects is essential. To determine whether environmental manganese is related to cancer at the county level in North Carolina (n = 100 counties; North Carolina 2000 population = 8,049,313), we carried out an ecological study using data from the North Carolina State Center for Health Statistics, North Carolina Geological Survey, US Geological Survey, and US Census. County-level all-cause and cancer mortality rates between 1997 and 2001 reported in deaths per 100,000 population associated by multivariable regression with logarithmically transformed groundwater (microgram per liter) and airborne (microgram per cubic meter) manganese concentrations by county measured between 1973 and 1979 (water) and in1996 (air). Models controlled for county characteristics. Median all-cause and cancer mortality rates by county in North Carolina (1997–2001) exceeded those of the USA (2000). For each log increase in groundwater manganese concentration, there was a corresponding county-level increase of 12.10 deaths/100,000 population in all-site cancer rates, 2.84 deaths/100,000 in colon cancer rates, and 7.73 deaths/100,000 in lung cancer rates. For each log increase in airborne manganese concentration, there was a corresponding county-level decrease of 8.10 deaths/100,000 population in all-site cancer rates, 3.28 deaths/100,000 in breast cancer rates, and 3.97 deaths/100,000 in lung cancer rates. Neither groundwater nor air concentrations of manganese correlated with county-level all-cause or prostate cancer death rates. These are the first data we know of to document a potential relationship between environmental manganese and population-level cancer death rates. The positive association between groundwater manganese and specific cancer mortality rates might be a function of the high concentrations measured, while the inverse relationship between air manganese and death rates might point toward adequate (e.g., healthy) county-level manganese exposures. Since manganese is replacing lead in gasoline globally, these ecological findings should be confirmed at the individual level or in animal models.     

Morbidity and mortality in acute viral hepatitides in a hyperendemic region. The role of viral hepatitis E

Official annual statistical data on morbidity in acute viral hepatitides (AVH), including the number of lethal cases, for 1985-1995 were analyzed. Mortality rates per 100,000 of the population at the period of 11 years were calculated for different age groups, sex and the place of residence. 396 and 99 patients were examined for the presence of serological markers of hepatitides A, B and E, respectively, at the periods of epidemic rises in morbidity and satisfactory epidemic situation. In the course of 11 years AVH caused the death of 22,405 persons. In 1985-1987 the average mortality level (ML) reached 12.3-17.8 per 100,000 of the population (with morbidity being 1,200-1,400 and was essentially higher among the rural population in comparison with the urban population. During these years the highest ML, was registered among children aged 0-2 years (190-50 per 100,000) and, among adults, mainly among women aged 20-29 years (21.4-19.6 per 100,000). During the years when the epidemic of AVH was absent, ML among these groups was essentially lower: 40-20 among children aged 0-2 years and 4-5 among women aged 20-29 years. In 1987 in the Fergana Valley hepatitis E was detected in 72.2% of all examined patients, and in the southern areas of the country in 68.7%. A sharp rise on mortality among women of the productive age at the period of the epidemic rise of AVH morbidity in the endemic region indicated that this epidemic was linked with hepatitis E. High ML among young children may be indicative of a highly unfavorable course of hepatitis E in the group of infants, which had never been registered before. This newly established regularity may be used for the retrospective diagnostics of the outbreak of hepatitis E.     

Cancer incidence in southern Iran, 1998-2002: results of population-based cancer registry

Purpose: The main aim of this study was to obtain population-based cancer incidence data for the entire population of Fars province in Iran, and to compare these rates with those obtained from a previous study in the same population ten years previously. Methods: Data were collected on all patients in major cities of Fars province who were diagnosed with cancer between 1998 and 2002. The data were computerized using SPSS (Chicago, IL) software, version 13.0, and MS EXCEL (Microsoft, Redmond, WA) software with Persian fonts. The results are presented as incidence rates of cases by site, sex, age, crude rates, and age-standardized rates per 100,000 person-years (ASRs), using the direct method of standardization to the world population. Results: During the 5-year study period, 8359 new cancer cases were registered. Diagnosis of cancer was based on histopathological criteria in 86.7%, clinical or radiological criteria in 9.4% and death certificate only in 3.9% of cases. According to the calculated ASRs, the 5 most frequent cancers in women were breast (13 per 100,000), stomach (4.4 per 100,000), lung and bronchus (2.9 per 100,000), uterus (2.7 per 100,000), and colon and rectum (2.6 per 100,000); and in men, the 5 most frequent types were stomach (9.2 per 100,000), bladder (6.8 per 100,000), lung and bronchus (6.3 per 100,000), lymphocytic leukemia (4.1 per 100,000), and skin melanoma (3.8 per 100,000). The ASR for all cancers in men was 64.5 per 100,000, and that for women was 55.5 per 100,000. Conclusion: Considering the limitations of this study, our results should be taken as the minimum incidence rates of cancers in Fars province, southern Iran. Significant differences were observed between the two study periods. However, we most likely have underestimated the frequencies of some tumors.     

Epidemiological pattern of scarlet fever in recent years

During the period of 1953-2001 scarlet fever morbidity level fluctuated from 670.3 to 65.9 per 100,000 of the population in Moscow and from 531.9 to 35.0 per 100,000 of the population of the Russian Federation. In recent years an increased morbidity was more pronounced in Moscow than in the Russian Federation as a whole. Children formed the greater part of scarlet fever patients, the cases of scarlet fever among children in Moscow occurring more often than, on the average, in Russia. As before, annual morbidity among children attending children's institutions was higher 3- to 4-fold than among children brought up at home. This difference was most sharply pronounced among young children during the first two years of their life. In contrast to morbidity observed during previous 20-30 years, a drop in morbidity among children during the first two years of their life was registered, while morbidity level among children aged 3-6 years and 7-14 years increased. Scarlet fever morbidity had a pronounced seasonal (autumn-winter) pattern. In a group of children aged 3-5 years who attended organized groups, on the average, 78.6% of scarlet fever cases fell on seasonal morbidity, the most prolonged one.     

Epidemiologic situation of brucellosis in the regions of the Republic of Dagestan affected by the flood of 2002

The Republic of Daghestan is at present one of the most unsafe territories in the Russian Federation with respect to brucellosis morbidity among humans. The figures of human morbidity in brucellosis grew from 3.4 per 100,000 of the population in 1999 to 10.5 per 100,000 of the population in 2002, thus exceeding the figures for the whole of Russia 15- to 20-fold. The analysis of human morbidity in the Kizlyar region (where the interregional regrouping of the cattle was made) after the natural calamity, as well a in other regions where live-stock was evacuated, indicated that by the end of 2002 an essential deterioration of the epidemiological situation took place in these regions. In view of grave epizootological situation and the absence of epidemiological safety in brucellosis in the Republic of Daghestan the sanitary, epidemiological and veterinary services should, together with other priority tasks in their work aimed at the liquidation of the emergency situation, pay greater attention to measures for the prevention of the spread of brucellosis.     

An epidemiological analysis of hemorrhagic fever with renal syndrome morbidity in the Republic of Bashkortostan in 1997

The outbreak of hemorrhagic fever with renal syndrome (HFRS) in the Republic of Bashkortostan, resulting in 10,057 registered cases of the disease (287 cases per 100,000 of the population), was analyzed. HFRS cases among the population were registered in 52 out of 54 regions of Bashkortostan. 31% of the total number of patients were the inhabitants of rural regions (170 cases per 100,000) and 69% were urban dwellers (295 cases per 100,000), mainly in Ufa (512 cases per 100,000). HFRS morbidity among males was fourfold higher than among females. In 70% of cases persons aged 20-49 years were affected. 5% of the total number of patients were children aged up to 14 years. In 34 cases (0.4%) the severe clinical course of the disease had a fatal outcome. Cases of HFRS were registered from April 1997 till March 1998 with the highest morbidity rate observed during the period of August-December. In most cases (46.8%) both urban and rural dwellers contacted infection during a short-term stay in the forest. As the result of the serological examination of the patients, all HFRS cases were etiologically attributed to hantavirus, serotype Puumala. The main natural reservoir of this virus and the source of human infection in Bashkortostan were bank voles (Clethrionomys glareolus), the domination species among small mammals in this region.     

The epidemiological characteristics of HIV infection in Turkmenistan

In the presence of the low spread of HIV infection a sharp increase in sexually transmitted diseases is noted. Nevertheless, taking into account a rise in STD, the reality of the potential risk of the spread of HIV is emphasized. Thus, in 1996 morbidity is syphilis was found to grow 7.2 times in comparison with 1992, amounting to 37.5 cases per 100,000 of the population; morbidity in gonorrhea amounted to 32.4 cases per 100,000 of the population with the proportion coming to medical institutions not exceeding 30%. A high proportion of hepatitis B virus carriers was also established (from 15% to 30% of healthy persons), while morbidity in virus hepatitides rose twofold for the period of 1994-1995. During recent years the service for the prophylaxis of AIDS was noted to considerably decrease measures on mass screening. At the same time the article attracts attention to the necessity of increasing the work on the dissemination of information and education on HIV/AIDS drug among addicts, prostitutes and homosexuals. The Draft National Program of the Prophylaxis of HIV infection and STD for 1998-2002 has been worked out. Great importance of methodological and financial assistance rendered since 1994 by international organizations, including WHO, UNFPA, etc., have been emphasized.     

The rising incidence and mortality of prostate cancer in Belgrade population

The purpose of this study was to analyze the epidemiological situation of prostate cancer in Belgrade population. Morbidity data were obtained from the Institute of Public Health of Serbia for the period 1999-2005. Mortality data for the period 1990-2006, were derived from the Statistical Office of Republic of Serbia. Average standardized incidence and mortality rates for the prostate cancer were 33.57 and 11.86 respectively. Standardized incidence rates of prostate cancer steadily increased from 29.34 per 100,000 in 1999 to 36.86 per 100,000 in 2005. In the observed period, the mortality rates significantly increased in the age groups 50-59 (y = 2.77+0.42x, p = 0.015), 70-79 (y = 61.92+10.70x, p = 0.000) and 80+ (y = 183.08+19.99x, p = 0.000). The average annual percentage of changes (AAPC) was the highest (7.2%) for the 70-79 age group, the lowest (0.1%) for the youngest group (< or = 50), and 5% for the total. The increase of prostate cancer incidence and mortality during the observed period in Belgrade population indicate urgent need for Serbian health professionals to adopt existing evidence-based cancer control and preventive measures. A national policy including prostate specific antigen (PSA) screening should be considered.     

HIV infection in Russia in 1998

The statistic information about the distribution of HIV-infected persons in 1998 in different regions of Russian Federation was presented 3169 new cases of HIV-infected persons of Russia registered by 11.5 months in 1998. This are only 82.2% cases in comparison of cases (3856) which registered in 1997. The total number HIV-infected persons registered by 1st of January 1987-16th of November 1998 was 10,193, among them 431 children. 112 children were infected during period of mother's pregnancy and parturitions.     

NTD prevalences in central California before and after folic acid fortification

BACKGROUND: In many regions, NTD prevalences were already declining prior to folic acid fortification. This study examined whether the declining prefortification (1989–1996) NTD prevalences continued into the postfortification period (1998–2003) in selected California counties. METHODS: This population‐based study used vital statistics data and birth defects registry data that were actively ascertained from medical records. The study population included all live births and stillbirths delivered in central California counties from 1989 to 2003. Cases included deliveries with NTDs during the same time period. RESULTS: For all NTDs combined, the slopes indicated that NTD prevalence was decreasing by 7.5 (slope: ?7.5; 95% CI: ?12.4, ?2.5) cases per 100,000 deliveries per year before fortification, whereas NTD prevalence was no longer decreasing after fortification. Comparison of the difference in the two slopes indicated that the postfortification slope exceeded the prefortification slope by 12.6 (95% CI: 2.6, 22.6) cases per 100,000 deliveries per year. CONCLUSIONS: Annual NTD prevalences in central California did not continue to decrease after implementation of folic acid fortification. Birth Defects Research (Part A) 2008. © 2008 Wiley‐Liss, Inc.     

Hepatitis A in Estonia (1990-1999)

During recent 10 years (1990-1999) essential changes occurred the epidemiology of viral hepatitis A (VHA) in Estonia: simultaneously with a decreased level of morbidity (morbidity rate per 100,000 of the population was 78.4 in 1990 and 7.7 in 1996, or 1,241 and 112 cases, respectively), a shift in the age structure of patients from children of preschool age to older age groups took place. Everyday contacts were the main established route of VHA transmission in recent years, but in more than 80% of cases the risk factors of the virus transmission remained obscure. During the regional outbreak of VHA in North Estonia in 1998 (937 out of 989 cases registered in the country) a rise in morbidity was observed among young people aged 15-29 years, when a wide spread of parenteral viral hepatitides B and C and drug addiction were registered in this region. During this outbreak VHA was transmitted mainly through everyday contacts. Still the considerable prevalence of injection drug users who practiced the group use of syringes and needles and took drugs from common containers, a sufficiently high level of the mixed forms of the disease (more than 18% of all registered cases of VHA), detected for the first time, make it possible to suggest that the parenteral transmission route could appear among persons belonging to the above mentioned group. Vaccination is regarded as the most effective measure for the prophylaxis of VHA.     

Incidence analyses and space-time cluster detection of hepatitis C in Fujian Province of China from 2006 to 2010

Background

There is limited epidemiologic information about the incidence of hepatitis C in China, and few studies have applied space-time scan statistic to detect clusters of hepatitis C and made adjustment for temporal trend and relative risk of regions.

Methodology and Principal Findings

We analyzed the temporal changes and characteristics of incidence of hepatitis C in Fujian Province from 2006 through 2010. The discrete Poisson model of space-time scan statistic was chosen for cluster detection. Data on new cases of hepatitis C were obtained from the Center for Disease Control and Prevention of Fujian Province. Between 2006 and 2010, there was an annualized increase in the incidence of hepatitis C of 23.0 percent, from 928 cases (2.63 per 100,000 persons) to 2,180 cases (6.01 per 100,000 persons). The incidence among women increased more rapidly. The cumulative incidence showed that people who were over 60 years had the highest risk to suffer hepatitis C (52.51 per 100,000 persons), and women had lower risk compared to men (OR = 0.69). Putian had the highest cumulative incidence among all the regions (86.95 per 100,000 persons). The most likely cluster was identified in Putian during March to August in 2009 without adjustment, but it shifted to three contiguous cities with a two-month duration after adjustment for temporal trend and relative risk of regions.

Conclusions/Significance

The incidence of hepatitis C is increasing in Fujian Province, and women are at a more rapid pace. The space-time scan statistic is useful as a screening tool for clusters of hepatitis C, with adjustment for temporal trend and relative risk of regions recommended.     

HIV infection and parenteral virus hepatitis in the Krasnodar territory

The analysis of the morbidity dynamics of HIV infection, hepatitis B and C in the Krasnodar territory for 1996-2003 is presented. The tendency of strengthening direct correlation between age-dependent rates in these groups of diseases has been established. The correlation coefficient (rxy) is at present +0.851 (HIV infection-virus hepatitis B) and +0.892 (HIV infection-virus hepatitis C). The highest levels of primary morbidity are registered in persons aged 20-39 years. The established epidemiological parallels between HIV infection and parenteral hepatitis require the development of the unified strategy of the prophylaxis of these diseases on the federal and regional levels.     

Epidemiology of hemorrhagic fever with renal syndrome in the north Volga-Viatka region

The results of the ecological and epidemiological study of hemorrhagic fever with the renal syndrome (HFRS) in the Kirov region for the period of 1987-2000 are presented. HFRS morbidity rate varied from 1.3 to 13.7 per 100,000 population, which corresponded to the figures registered in the Volga Vyatka region. Cases of HRFS were mainly (90%) registered in three southern districts of the region. The moderate degree of correlation between morbidity rate and the number of wild mammals (r = 0.55) was established. Periodic morbidity rise occurred every 3 years. In 1998-2000 the contamination of wild mammals with HFRS virus increased and reached 7.6-9.5%. Infection factors connected with everyday human activities somewhat prevailed, industrial and agricultural types of infection constituting 43.8%. Males aged 20-49 years prevailed among the patients. Morbidity rate among urban dwellers exceeded that among town residents.     

Incidence of multiple myeloma in Kailuan cohort: A prospective community-based study in China

BackgroundPrevious retrospective studies showed that the incidence and mortality rates for MM in China were lower than those in western countries. A large-scale prospective study on incidence and mortality rates of MM is still lacking.MethodsBased on the prospective Kailuan Cohort study in China, we included all patients with MM in Kailuan Cohort from June 1, 2008 to December 31, 2016. Using the numbers of diagnosed cases and deaths during the study period as the numerators and the corresponding observed person-years as the denominators respectively, we calculated crude incidence and mortality rates. The 95% confidence intervals for crude incidence rate and mortality rate were estimated base on Poisson distribution. Rates were standardized by direct standardization according to the China population in 2000 and Segi’ world standard population.ResultsA total of 22 members from Kailuan Cohort were first diagnosed with MM between 2008 and 2016. The calculated crude incidence rates were 2.8 (95% CI, 1.7–4.2) per 100,000 person-years for all participants. The standardized incidence rate was 0.9 per 100,000 person-years (95% CI, 0.5–2.1) when standardized by 2000 China population census data, and 1.0 per 100,000 person-years (95% CI, 0.6–1.8) when standardized by Segi’s world standard population (WSP). The calculated crude mortality rates were 2.3 (95% CI, 1.4–3.6) per 100,000 person-years. The mortality standardized by 2000 China population census data was 0.7 per 100,000 person-years (95% CI, 0.3–1.9), and 0.9 per 100,000 population (95% CI, 0.5–1.7) when standardized by Segi’s WSP. Both incidence and mortality for males were higher than that for females almost in all age groups. Both rates increased steadily with age.ConclusionIn this community-based prospective cohort study, we found that the incidence of MM in China was far lower than that in American and Europe.     

Estimating the Number of Persons Who Inject Drugs in the United States by Meta-Analysis to Calculate National Rates of HIV and Hepatitis C Virus Infections

Background

Injection drug use provides an efficient mechanism for transmitting bloodborne viruses, including human immunodeficiency virus (HIV) and hepatitis C virus (HCV). Effective targeting of resources for prevention of HIV and HCV infection among persons who inject drugs (PWID) is based on knowledge of the population size and disparity in disease burden among PWID. This study estimated the number of PWID in the United States to calculate rates of HIV and HCV infection.

Methods

We conducted meta-analysis using data from 4 national probability surveys that measured lifetime (3 surveys) or past-year (3 surveys) injection drug use to estimate the proportion of the United States population that has injected drugs. We then applied these proportions to census data to produce population size estimates. To estimate the disease burden among PWID by calculating rates of disease we used lifetime population size estimates of PWID as denominators and estimates of HIV and HCV infection from national HIV surveillance and survey data, respectively, as numerators. We calculated rates of HIV among PWID by gender-, age-, and race/ethnicity.

Results

Lifetime PWID comprised 2.6% (95% confidence interval: 1.8%–3.3%) of the U.S. population aged 13 years or older, representing approximately 6,612,488 PWID (range: 4,583,188–8,641,788) in 2011. The population estimate of past-year PWID was 0.30% (95% confidence interval: 0.19 %–0.41%) or 774,434 PWID (range: 494,605–1,054,263). Among lifetime PWID, the 2011 HIV diagnosis rate was 55 per 100,000 PWID; the rate of persons living with a diagnosis of HIV infection in 2010 was 2,147 per 100,000 PWID; and the 2011 HCV infection rate was 43,126 per 100,000 PWID.

Conclusion

Estimates of the number of PWID and disease rates among PWID are important for program planning and addressing health inequities.     

Comparing an IPM pilot program to a traditional cover spray program in commercial landscapes

An integrated pest management (IPM) pilot program for landscape plants was implemented during 1997 and 1998 on two commercial, two residential, and one institutional property managed by landscape professionals. When compared with preprogram, calendar-based cover spray program costs at these sites in 1996, the IPM program was cost-effective at one of the five sites in both 1997 and 1998, and cost effective at a second additional site in 1998 when the cooperator, initially skeptical of IPM, discontinued calendar-based cover sprays performed in 1996 and 1997. The mean cost per site was $703.40 (preprogram), $788.26, and $582.22 in 1996, 1997, and 1998, respectively. Volume of pesticide applied decreased a mean of 86.3% on the four sites not receiving cover sprays and increased 2.3% at site 2 (still using cover sprays) in 1997. In 1998, pesticide volume was reduced an average of 85.3% at all five sites compared with preprogram levels. The majority of insect pest problems were corrected using spot sprays of insecticidal soap or horticultural oil or by physical means such as pruning. One-third of the woody plant material on the commercial and institutional sites consisted of holly, juniper, and azalea. The most prevalent pests encountered were mites (Tetranychidae), aphids, lace bugs, scales, whiteflies, and Japanese beetle. Spiders were the most abundant group of predatory arthropod and ants, green lacewings, and lady beetles were also well represented in the managed landscapes.     

Spread of bloodborne viruses among Australian prison entrants.

OBJECTIVES--To assess spread of bloodborne viruses among prison entrants in Victoria, Australia. DESIGN--Voluntary confidential testing of all prison entrants for markers of exposure to bloodborne viruses with collection of minimal data on demography and risk factors over 12 months. SETTING--Her Majesty''s Prisons, Pentridge and Fairlea, Victoria, Australia. SUBJECTS--3429 male and 198 female prison entrants (> 99% of all prison entrants); 344 entered prison and were tested more than once. MAIN OUTCOME MEASURES--Prevalence and incidence of antibodies to HIV, hepatitis B, and hepatitis C viruses, and minimal data on risk factors. RESULTS--1562 (46%) gave a history of use of injected drugs, 1171 (33%) had antibody to hepatitis B core antigen, 1418 (39%) were anti-hepatitis C positive including 914 (64%) of the men who injected drugs, 91 (2.5%) were positive for hepatitis B surface antigen, and 17 (0.47%) were positive for antibody to HIV. Incidence rates for infection with hepatitis B and C virus were 12.6 and 18.3 per 100 person years, respectively; in men who injected drugs and were aged less than 30 years (29% of all prison entrants) these were 21 and 41 per 100 person years. Seroconversion to hepatitis B or C was associated with young age and shorter stay in prison. Only 5% of those who were not immune to hepatitis B reported hepatitis B immunisation. CONCLUSIONS--Hepatitis B and C are spreading rapidly through some populations of injecting drug users in Victoria, particularly among men aged less than 30 years at risk of imprisonment in whom rates of spread are extreme; this group constitutes a sizeable at risk population for spread of HIV. This spread is occurring in a context of integrated harm reduction measures outside prisons for prevention of viral spread but few programmes within or on transition from prisons; it poses an urgent challenge to these programmes.     

Seasonal dynamics of cereal aphids on Russian wheat aphid (Homoptera: Aphididae) susceptible and resistant wheats

Field experiments were conducted in 1997 and 1998 to evaluate the impact of resistance to Russian wheat aphid, Diuraphis noxia (Mordvilko), on the cereal aphid complex in wheat. Two spring wheats were planted: the variety "Centennial" (Russian wheat aphid susceptible) and the advanced line IDO488 (Russian wheat aphid resistant). IDO488 incorporates the resistance found in PI 294994 into a Centennial background. Field plots were artificially infested with adult D. noxia and sampled weekly. The most abundant aphid species in 1997 were Metopolophium dirhodum (Walker), Sitobion avenae (F.), D. noxia, and Rhopalosiphum padi (L.). In 1998, the order of abundance was M. dirhodum, R. padi, S. avenae, and D. noxia. The resistant genotype had significantly fewer D. noxia than the susceptible one during both years. However, plant genotype had no significant effect on the other aphid species in either year. Both the initial density of D. noxia and plant growth stage, had a significant effect on D. noxia population development, but had no effect on the other aphid species. There was no interaction between D. noxia resistance and the population density of the other aphid species observed.