Epidemiology and infection.

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Epidemiology and Outcome of Nosocomial and Community Onset Bloodstream Infection

Epidemiology and Outcome of Nosocomial and Community Onset Bloodstream Infection

Most studies of the epidemiology of bloodstream infection focus on nosocomial infections alone. Our study examines both community-onset and nosocomial bloodstream infections, al- lowing us to estimate the proportion of all bloodstream infec- tion mortality that is associated with nosocomial versus com- munity-onset infections. We found that 72% of the crude mortality and 71% of the attributable mortality occurred among patients with nosocomial bloodstream infection. In ad- dition, hospital acquisition (nosocomial status) of bloodstream infection was strongly associated with mortality in our multi- variate model. The nosocomial status variable almost certainly served as a marker of underlying illness variables for which it is difficult to completely adjust. However, our data suggest that there is substantial mortality attributable to nosocomial blood- stream infections; indeed, our attributable mortality estimate for nosocomial bloodstream infections was more than twice that for community-onset bloodstream infections. Our multi- variate linear regression model examining factors associated with total costs also demonstrated that hospital acquisition of bloodstream infection was strongly associated with increased costs. This model included length of hospital stay.
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Epidemiology of Rotavirus Infection in Certain Countries

Epidemiology of Rotavirus Infection in Certain Countries

has fallen for the developing countries, that account for about 600,000–800,000 deaths per year, that is >85% of deaths occurring in low- income countries of Asia and sub-Saharan Africa among children 5 years old (3, 5, 7, 10, 11). Some differences in the rotavirus epidemiology between tropical developing countries and developed countries in temperate climates could have direct consequences on future plans to administer rotavirus vaccine. First, in tropical countries, rotavirus infection occurs in all seasons, but winter peaks of infection are seen in developed countries. The seasonality could describe the age differences of illness among children 6 to 8 months in developing countries, compared with that among children 14 to 18 months in developed countries (12, 13). In the other countries around the world demonstrated that group A Rotavirus infection is responsible for 13 to 45% of all cases of diarrhea in children less than five years of age, which children between the ages of 6 and 24 months are at greatest risk for developing severe diarrhea (3). Rotavirus surveillance could identify important features in the local epidemiology, which help estimates of the burden of rotavirus diarrhea, create an awareness of rotavirus disease among pediatricians, and provide experience on the most efficient ways to monitor the impact of a rotavirus vaccine (14, 15). In June 2006, the World Health Organization Regional Office for Africa with use of WHO standardized methodology, initiated rotavirus surveillance in selected African countries. Accordingly, children <5 years of age who were hospitalized with severe diarrhea were enrolled, and stool specimens were collected for detection of rotavirus strains by a commercial enzyme immunoassay. The results indicate that rotavirus is a major cause 40% of severe diarrheal disease at 14 sites in 11 African countries. According to the similar study in Vietnam Rotavirus was identified in 56% of the 5768 patients during the period between1998 –2000 (7, 10, 11, 16, 17). Despite the effect of rotavirus infection in children morbidity and mortality worldwide, very little data on illness caused by Rotavirus has been published in Iran (18, 19). However,
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Molecular epidemiology of endemic Clostridium difficile infection

Molecular epidemiology of endemic Clostridium difficile infection

The Anaerobic Reference Unit of the Public Health Laboratory Service has confirmed the endemic strain identified here as PCR ribotype 1 (J. Brazier, personal communication). This strain is known to be endemic in 33 of 58 hospitals in England and Wales [32]. It is interesting to speculate on the high prevalence of this strain in hospitalized patients [10]. Results from the present study suggest a relationship may exist between CDI incidence and the level of C. difficile spore contamination in the hospital environ- ment. Thus, more cases of endemic infection result in the release of more spores into the environment, creating the potential for more cases of endemic infection. However, although several C. difficile strains were found in the study, only genotype I was predominant. This implies that strain-specific charac- teristics have contributed to persistence. This is the first comprehensive insight into the molecular epi- demiology of endemic C. difficile, particularly that associated with a recently recognized epidemic strain, Understanding the epidemiology and virulence of prevalent strains is important if CDI is to be successfully controlled.
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The epidemiology of Clostridium difficile infection in Australia

The epidemiology of Clostridium difficile infection in Australia

Although a comprehensive review was carried out, several limitations were noted. First, only two studies were identified that reported the seasonality of CDI in Southern Hemisphere countries [14,15]. Furthermore, both studies were conducted in Australia. This may limit the generalizability of the findings for Southern Hemisphere countries only to Australia. However, the identified gap in information should encourage further investigation particularly in coun- tries in South America, Africa and Asia. Second, there was a small number of studies from countries located between the Tropic of Cancer and the Tropic of Capricorn. The study con- ducted by Wong-McClure et al . [30] in Costa Rica was the only study from the Northern Hemisphere located in a tropical zone, precluding the comparison between the seasonality of CDI in temperate and sub-tropical/tropical climates. Despite the documented changes in CDI epidemiology [2], the increase in community-acquired CDI [31], and the different risk profiles between community- and hospital-acquired CDI patients [32], our study was also limited by the inability to compare the community- and hospital-acquired CDI seasonal patterns. Despite the increasing incidence of CDI among the paediatric population [33] only one study (Deodari et al . [34]) was identified that described the CDI seasonality in children; therefore, generaliz- ability of the findings may be limited among this population. Potential factors that may con- tribute to differences in monthly CDI incidence that could not be accounted for in this review, such as hospital characteristics (e.g. staffing, overcrowding), CDI diagnosis ascertainment, se- verity of underlying illness, infection control practices, and CDI strain need to be assessed in future studies.
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Epidemiology of Clostridium difficile infection in Asia

Epidemiology of Clostridium difficile infection in Asia

Clostridium difficile causes infection ranging from mild diarrhoea to pseudomembranous colitis (PMC), prima- rily in older age patients who have been exposed to anti- biotics. Epidemics of C. difficile infection (CDI) have occurred in North America and Europe over recent de- cades and the epidemiology of CDI in these regions is well-documented. These epidemics have demonstrated the need for surveillance of the international movement of C. difficile strains [1]. Circulating strains in Asia, as in other regions, have the potential to spread internatio- nally, warranting close monitoring of the prevalence and molecular epidemiology of CDI in the region. Indeed, it is likely that the variant toxin A-negative/ toxin B-positive (A - B + ) ribotype 017 C. difficile strain origi- nated in Asia. One particular clindamycin-resistant ribotype 017 strain of apparent clonal origin has domi- nated international typing studies of A - B + strains and has been the cause of epidemics in Canada, the Netherlands and Ireland [2-4]. Unfortunately, limited data are available on CDI in Asia. A recent survey found that awareness of CDI in physicians is poor in Asia, with underestimation of
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<p>Epidemiology of <em>Plasmodium falciparum</em> infection and drug resistance markers in Ota Area, Southwestern Nigeria</p>

<p>Epidemiology of <em>Plasmodium falciparum</em> infection and drug resistance markers in Ota Area, Southwestern Nigeria</p>

Prevailing factors such as fear of needles, risk of infec- tions and perhaps traditional taboos may serve as a deterrent to the successful diagnosis of malaria, especially in children and among rural dwellers. However, most commonly used malaria diagnoses for epidemiological surveys rely on the use of blood drawn using needles, which in fl icts pain on the subject. Because young children are the most vulnerable to infection and disease, they tend to constitute the de facto sentinel group used for most malaria surveys. Their unwill- ingness to participate in epidemiological survey owing to the invasiveness of the diagnosis may grossly mitigate malaria surveillance and control. This study showed high detection rates comparable to blood diagnosis of molecular markers of antimalarial resistance in the study area and reported the absence C580Y or A578S SNP; the most frequent K13 allele observed in Africa, associated with artemisinin resistance in sub-Saharan African parasites and those found in Southeast Asia. 30,31
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Molecular Epidemiology of Astrovirus Infection in Barcelona, Spain

Molecular Epidemiology of Astrovirus Infection in Barcelona, Spain

The annual incidence of each serotype is shown in Fig. 3. In 1997–1998, HAstV-1 was the only serotype detected, while in 1998–1999, five different serotypes affected the studied popu- lation, with HAstV-3 being the most prevalent, followed by HAstV-4. In the following 1-year period, HAstV-1 reappeared as the most common type accounting for 67% of the cases, while HAstV-4 and HAstV-8 showed a decreasing incidence and HAstV-2 and HAstV-3 were not detected. The analysis of the genetic variability of isolates allowed us to describe the emergence of a different HastV-1 strain during 1999–2000 (see below). During the study period, one child suffered from an episode of HAstV-3 diarrhea in November 1998 and had a subsequent episode of HAstV-1 infection 9 months later, sug- gesting a lack of heterotypic immunity between the different antigenic types, which could be responsible for the changes in serotype distribution observed in consecutive years.
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Epidemiology and Risk Factors of Infection in Early Childhood

Epidemiology and Risk Factors of Infection in Early Childhood

This prospective Danish birth cohort study revealed that otherwise healthy children experienced a median of 14 simple infectious episodes throughout the first 3 years of life (mean 15; IQR 10–18; range 2–43) with substantial variation in frequency between individuals. Only crowding in day care had a significant but modest influence on the overall incidence of infections and incidence of URTI, whereas LRTI incidence was associated with maternal smoking, caesarean delivery, older siblings, and early day care attendance. When including 84 environmental and constitutional covariates with an explorative SPCA approach, we were only able to describe 8.4% of the large variance in infection frequency. With these findings, we suggest that host factors are the major determinants of infection susceptibility in early childhood. Strengths and Limitations
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The epidemiology of campylobacter infection in dogs in the context of the risk of infection to humans

The epidemiology of campylobacter infection in dogs in the context of the risk of infection to humans

The prevalence of C. upsaliensis and C. jejuni was high in both kennels, suggesting that this population of dogs, particularly younger dogs, may be an important source of C. upsaliensis and C. jejuni infection to dogs and to humans via dogs. Although the rescue kennel had a higher prevalence of both C. upsaliensis and C. jejuni carriage in dogs, no statistically significant difference was found between the two different kennel types for Campylobacter spp. carriage. Neither could this study find any significant differences in the carriage of Campylobacter spp. found in dogs on entry compared to the subsequent days of sampling for either of the kennels. Dogs carrying C. upsaliensis appeared to shed this species in the majority of samples, whereas the duration of C. jejuni shedding appeared to be limited. This suggested a commensal role for C. upsaliensis, whereas carriage of C. jejuni may have been the result of a transient infection. Some dogs however, had no Campylobacter spp. isolated from their faeces at any stage during the study. The majority of positive dogs entered the kennels already carrying Campylobacter spp. and although the numbers of dogs who did not shed Campylobacter spp. until after arrival were few, when this did occur, it involved C. jejuni proportionally
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Epidemiology of and risk factors for infection with extended-spectrum &beta;-lactamase-producing carbapenem-resistant Enterobacteriaceae: results of a double case&ndash;control study

Epidemiology of and risk factors for infection with extended-spectrum &beta;-lactamase-producing carbapenem-resistant Enterobacteriaceae: results of a double case&ndash;control study

Results: A total of 149 patients with CRE infection caused by Enterobacter cloacae (n=74), Escherichia coli (n = 38), and Klebsiella pneumoniae (n = 37) were identified in Chongqing, Southwestern China, between January 2011 and December 2014. Of the 35 isolates detected with carbapenemase-related genes, 16 isolates had New Delhi metallo- β -lactamase (NDM), nine isolates had K. pneumoniae carbapenemase (KPC), seven isolates had imipenemase (IMP), and four isolates had oxacillinase (OXA)-1. One strain of enterobacter cloacae carried both NDM-1 and IMP-8 genes. ESBL isolates included the genes CTX-M (72/149), SHV (64/149), and TEM (54/149). All ESBL-CRE isolates exhibited ertapenem resistance, and the rate of cephalosporin resistance was relatively high in general. Independent risk factors for infection with ESBL-CRE included previous exposure to β -lactam antibiotics, transfer from another hospital, and some underlying diseases. In addition, solid tumors, hypoalbuminemia, and central venous catheters were independent predictors of mortality in patients with ESBL-CRE infection.
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Comparative Epidemiology of Bartonella Infection in Dogs and Humans

Comparative Epidemiology of Bartonella Infection in Dogs and Humans

DNA in 3 samples, all of which were subsequently PCR positive by subculture or enrichment culture. In samples from 5 persons, pre-enrichment was necessary, and in 5 other persons, sequential sampling was necessary to detect Bartonella infection. Intermittent bacteremia, as occurs in B. henselae–infected cats (12), antimicrobial drug administration, low bacterial copy numbers, and low inoculum volume (1 mL) may have contributed to intermittent detection or inability to isolate Bartonella spp. from some participant samples. Although an improvement over historical isolation approaches, our results emphasize ongoing limitations associated with the detection of Bartonella infection. Obtaining stable Bartonella subcultures (n = 5 in this study) has proven problematic for other specialized laboratories that routinely culture for Bartonella spp. (3,4). To our knowledge, the B. vinsonii subsp. berkhoffii type II isolate described in our study is the only type II human isolate reported to date (8). Various combinations of B. henselae and B. vinsonii subsp. berkhoffii strain types were detected in the same blood sample or sequential blood samples. The coexistence of B. henselae genetic variants has been described among primary patient isolates, which suggests that multiple genotypes may emerge within the same person (13).
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<p>Epidemiology of Dermatophyte and Non-Dermatophyte Fungi Infection in Ethiopia</p>

<p>Epidemiology of Dermatophyte and Non-Dermatophyte Fungi Infection in Ethiopia</p>

Geographic location, health care, immigration, climate (temperature, humidity, wind, etc.), overcrowding, envir- onmental hygiene culture, awareness to dermatophytes, age of individuals, hygiene and socioeconomic conditions have been described as major factors for these variations of dermatophyte epidemiology. 9–12 Children ’ s between the ages of 4 and 16 years are more at risk due to more contact to different sources and inadequate amount of fungi-inhi- biting fatty acids synthesized predisposed them to derma- tophytic infections. 13,14

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The epidemiology of HIV infection in Zambia

The epidemiology of HIV infection in Zambia

Our most important finding is illustrated in the contrast between Figures 1 and 4. A pronounced change of the odd ratios in Lusaka and Copperbelt is observed following application of the model described here. The spatial distributions of the risk of HIV infection we showed are of course influenced by the variable selection in the model. Place of residence and spatial distribution are both chosen as the factors in geo- additive regression model. However, it is possible that the place of residence shared the effect of geographic distribution of the regions, especially in Lusaka and Copperbelt as the country is highly urbanised and almost one-half of the country's twelve million people are concentrated in a few urban zones.
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The Epidemiology of Pertussis: A Comparison of the Epidemiology of the Disease Pertussis With the Epidemiology of Bordetella pertussis Infection

The Epidemiology of Pertussis: A Comparison of the Epidemiology of the Disease Pertussis With the Epidemiology of Bordetella pertussis Infection

During the last 2 decades a number of studies have provided data that are useful in the delineation of B pertussis infection from reported pertussis. These studies include the study of prolonged cough ill- nesses in adolescents and adults, serologic studies over time used to determine infection rates in pop- ulations, and studies in defined populations to de- termine rates of symptomatic infections in adoles- cents and adults.

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PREVALENCE OF CYTOMEGALOVIRUS IGG ANTIBODIES, POTENTIAL RISK FACTORS AND AWARENESS OF CONGENITAL CYTOMEGALOVIRUS AMONG FEMALE DOCTORS

PREVALENCE OF CYTOMEGALOVIRUS IGG ANTIBODIES, POTENTIAL RISK FACTORS AND AWARENESS OF CONGENITAL CYTOMEGALOVIRUS AMONG FEMALE DOCTORS

Staff in hospitals may run an increased risk of cytomegalovirus (CMV) contact infection leading to a congenital CMV feto-pathy during pregnancy. The main risk factor is close contact with unapparent carriers of CMV among infants etc. We therefore examined CMV sero-prevalence and possible risk factors for CMV infection among staff at a Mother- children’s hospitals. To our knowledge, this is the first documented data in Sana'a city regarding the epidemiology of and knowledge of HCMV among Yemeni female doctors. According to the current study high percentage of Anti-HCMV IgG antibodies (86.5%) among participating doctors indicated either past infection (apparently sub-clinical), current active sub-clinical disease or exposure to virus without active disease. After HCMV exposure or infection, IgG remains for the rest of life as protective antibody against the next infection. However, the primary HCMV infection needs to be elucidated either as recurrent or new infection by specific HCMV IgG avidity test. This sero-prevalence of HCMV IgG antibody in our study (86.5%) was slightly higher than what reported in China (81.7%) 14 and much higher than reported in developed countries as France (51.1%) 15 and UK (51.5%) 16 among female doctors but lower to countries like Thailand, where figures of 100% sero- prevalence reported 17 . Also, when we compared current finding with pregnant women in previous Yemeni and Arab studies, current finding was lower than Sana’a city (100%) 18 ; Hodeida city (98.7%) 19 , Taiz city (99%) 20 , Iraq (100%) 21 , Egypt (100%) 22 , and Sudan (97.5%) 23 , and also lower than that of Iran (98.8%) 24 , and Nigeria (94.8%) 25 . These high rates may be due to the poor hygienic practices and low socioeconomic status that might play significant roles in increasing the rate of HCMV exposure and infection. Despite the general very high sero-prevalence of HCMV infection,
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Malaria: progress, perils, and prospects for eradication

Malaria: progress, perils, and prospects for eradication

Vector biology and control The intensity and pattern of transmission of malaria-causing parasites, and therefore the epidemiology of infection and disease, are largely a function of the [r]

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Statics and dynamics of malaria infection in Anopheles mosquitoes

Statics and dynamics of malaria infection in Anopheles mosquitoes

As in the models used to derive the classic formulae in malaria epidemiology, the following derivations assume that mosquito populations are homogeneous, ignore mosquito senescence, and assume that adult mosquito population size is constant. Moreover, the formulae assume that mosquitoes bite humans at random and uni- formly. Also, the formulae assume that an infected mos- quito never becomes uninfected, and so focus on the initial infection. These assumptions, which are called the classic assumptions, are useful approximations or ideali- zations that form a starting point for more complicated analysis. The classic assumptions are frequently violated in real mosquito populations. For example, mosquito density fluctuates seasonally; emergence and survivorship may depend on environmental factors, such as rainfall, temperature and humidity. Adult mosquitoes may senesce, or there may be intrinsic differences in mortality rates, called demographic frailty. Mosquitoes bite some people more than others [13], either due to inherent mos- quito preferences [14] or proximity to larval habitat [15- 18].
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Sphingobacterium respiratory tract infection in patients with cystic fibrosis

Sphingobacterium respiratory tract infection in patients with cystic fibrosis

Conclusions: This is the first Italian report about respiratory tract infections by Sphingobacterium in CF patients. In our cohort, these infections were not associated with a deterioration of pulmonary function during the follow-up period. Although the exact role of this microorganism in CF lung disease is unknown and the number of infected patients was small, this study could represent an important starting-point for understanding the epidemiology and the possible pathogenic role of Sphingobacterium in CF patients.

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A review of mixed malaria species infections in anopheline mosquitoes

A review of mixed malaria species infections in anopheline mosquitoes

Mixed species infections in patients are often under reported, with a tendency to over report the more danger- ous P. falciparum. In endemic areas, where the prevalence of malaria revealed by sensitive PCR methods is much higher than evident from microscopy, high rates of mixed blood stage infection (~20%) have been reported, presum- ably because both infections are carried chronically [6,7]. Lower rates of mixed species infection occur in sympto- matic non-immunes presenting with acute falciparum malaria in low transmission settings. Even with sensitive PCR detection of low parasitaemia, the proportion of mixed infections detected does not approach the 30 to 50% required to explain the proportion of vivax malaria episodes, which follow P. falciparum malaria in these same patients. Simultaneous infection studies in the malaria therapy of neurosyphilis and in volunteers clearly showed that mixed infection could occur from simulta- neous inoculation, that pre-erythrocytic development of P. falciparum was more rapid, and that in the blood stage infection P. falciparum tended to suppress P. vivax, so low level P. vivax parasitaemia might still be missed by current diagnostic methods [8-10]. Plasmodium vivax may also suppress P. falciparum; up to 10% of acute vivax malaria episodes in Thailand are followed shortly after by P. falci- parum infections without reinfection [3,11]. Blood stage infections in which both parasites are detectable could either derive from simultaneous inoculation of the sporo- zoites of the two species from a doubly infected anophe- line mosquito, or a recently acquired infection of one species might supervene a chronic infection with the other. As transmission intensities in most of South East Asia are very low (EIRs typically < 1/year) the probabilities of separate inoculations within a narrow time window are extremely low [12]. To resolve these questions and under- stand better the epidemiology of mixed species infection in different transmission settings we examined the pub- lished literature on immunological and molecular parasite species identification in anopheline vectors in malaria endemic areas.
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American Journal of Zoological Research

American Journal of Zoological Research

Abstract Background: Parasitic diseases are an important cause of morbidity and mortality in donkeys. Effort must be given to control and prevention of parasitic disease transmission within a facility and among animal populations. Therefore, the aim of the present study was to assess the epidemiology of parasitic infection among working donkeys in Qubaish locality, Western Kurdufan State of Sudan. Methodology: This is a retrospective cross sectional study conducted in Western Sudan to assess the epidemiologic burden of parasitic infections among donkeys. The study included 200 working donkeys. Results: The most frequently detected parasite was Strongylus spp representing 30/62 (48%) followed by mixed infection, Cyathostomes, Dictyocaulus arnfieldi, Oxyuris equi, parascaris equorum, constituting 15/62(24.2%), 13/62(21%), 2/62(3.2%), 1/62(1.6%), 1/62(1.6%), respectively. Conclusion: Strongylus and Cyathostomes helminthes were prevalent among working donkeys in West Kurdufan State, Sudan, which necessitate for urgent effective control measures including treatment, prevention and drug resistant testing.
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