Human Infection Rates Research Articles

Evidence of Leishmania (Leishmania) infantum infection in dogs from Juiz de Fora, Minas Gerais State, Brazil, based on immunochromatographic dual-path platform (DPP®) and PCR assays.

In Brazil, domestic dogs are branded as the primary reservoir for zoonotic visceral leishmaniasis, due to the clear positive correlation observed between human and canine infection rates. This study aimed to carry out a serological survey of canine visceral leishmaniasis (CVL) in dogs housed at a public kennel in the municipality of Juiz de Fora, Minas Gerais State, Brazil, using the immunochromatographic TR DPP® CVL rapid test. Additionally, conventional and/or real time PCR assay was used to detect and confirm L. infantum infection in the DPP positive dogs only. Of the 400 dogs studied, most did not present clinical signs for CVL (p < 0.05), and fifteen (3.8%) were seropositive in the DPP test. There was no statistically significant difference between the DPP seropositive dogs and the clinical signs of the disease (p > 0.05). Both conventional and real time PCR tests confirmed L. infantum infection in nine (75.0%) of the twelve DPP seropositive dogs that remained alive during the follow-up period. This study is the first seroepidemiologic survey of CVL held in the city of Juiz de Fora, and the results reinforce the idea that this disease is currently in a process of expansion and urbanization in Brazil. Furthermore, this study highlights the use of the DPP test as an alternative for diagnosing CVL in large and mid-sized cities, due to its ease of implementation.

A Thirty-year Review of Vulvar Cancer in Jamaica, 1978 to 2007.

To evaluate the trends in vulvar cancer between 1978 and 2007 in Kingston and St Andrew, Jamaica, with respect to age-standardized rates and histologic types. All cases of vulvar cancer recorded in the Jamaica Cancer Registry from 1978 to 2007 were extracted and analysed for age distribution and histologic type. There were 78 cases (one person of unknown age) of vulvar cancer recorded over the 30-year period. Sixty per cent of the affected patients were between 50 and 80 years old. The most common histologic type of vulvar malignancy was squamous cell carcinoma (82%). There was a decline in age-standardized incidence rates of both vulvar cancers overall and vulvar squamous cell carcinoma over the 30-year period. Squamous cell carcinoma is the most common vulvar malignancy in the Jamaican population, and affects primarily older women. Despite high prevalence rates of high-risk human papillomavirus infection, no increase in the age-standardized incidence of vulvar squamous cell carcinoma was identified.

E. coli O157 on Scottish cattle farms: evidence of local spread and persistence using repeat cross-sectional data.

BackgroundEscherichia coli (E. coli) O157 is a virulent zoonotic strain of enterohaemorrhagic E. coli. In Scotland (1998-2008) the annual reported rate of human infection is 4.4 per 100,000 population which is consistently higher than other regions of the UK and abroad. Cattle are the primary reservoir. Thus understanding infection dynamics in cattle is paramount to reducing human infections.A large database was created for farms sampled in two cross-sectional surveys carried out in Scotland (1998 - 2004). A statistical model was generated to identify risk factors for the presence of E. coli O157 on farms. Specific hypotheses were tested regarding the presence of E. coli O157 on local farms and the farms previous status. Pulsed-field gel electrophoresis (PFGE) profiles were further examined to ascertain whether local spread or persistence of strains could be inferred.ResultsThe presence of an E. coli O157 positive local farm (average distance: 5.96km) in the Highlands, North East and South West, farm size and the number of cattle moved onto the farm 8 weeks prior to sampling were significant risk factors for the presence of E. coli O157 on farms. Previous status of a farm was not a significant predictor of current status (p = 0.398). Farms within the same sampling cluster were significantly more likely to be the same PFGE type (p < 0.001), implicating spread of strains between local farms. Isolates with identical PFGE types were observed to persist across the two surveys, including 3 that were identified on the same farm, suggesting an environmental reservoir. PFGE types that were persistent were more likely to have been observed in human clinical infections in Scotland (p < 0.001) from the same time frame.ConclusionsThe results of this study demonstrate the spread of E. coli O157 between local farms and highlight the potential link between persistent cattle strains and human clinical infections in Scotland. This novel insight into the epidemiology of Scottish E. coli O157 paves the way for future research into the mechanisms of transmission which should help with the design of control measures to reduce E. coli O157 from livestock-related sources.

Abnormal Pap Tests and Human Papillomavirus Infections Among HIV-Infected and Uninfected Women Who Have Sex With Women

To estimate the frequency of abnormal Pap and human papillomavirus (HPV) positivity among human immunodeficiency virus (HIV)-seropositive and -seronegative women who have sex with women (WSW). Pap and HPV DNA polymerase chain reaction tests were obtained every 6 months from women in a US cohort of HIV-seropositive and -seronegative women. Women who have sex with women were women reporting no male and at least 1 female sex partner for 5 years. They were frequency matched 1:5 to women reporting sex only with men (WSM) and assessed using multivariable generalized estimating equation logistic regression models. Paps at study entry were abnormal in 12 (21%) of 49 HIV-seropositive WSW, 151 (64%) of 245 HIV-seropositive WSM, 3 (9%) of 24 HIV-seronegative WSW, and 16 (11%) of 120 HIV-seronegative WSM. Human papillomavirus was found at entry in 18 (42%) HIV-seropositive WSW, 109 (52%) HIV-seropositive WSM, 6 (27%) HIV-seronegative WSW, and 13 (13%) HIV-seronegative WSM. After controlling for HIV serostatus and CD4 count, WSW had marginally lower odds than WSM of Pap abnormality (odds ratio = 0.59, 95% confidence interval = 0.33-1.03) and of HPV (odds ratio = 0.53, 95% confidence interval = 0.32-0.89). After controlling for partner's gender, HIV seropositivity and lower CD4 count were associated with any HPV, oncogenic HPV, any abnormal Pap result, and high-grade squamous intraepithelial lesion or worse (p < .0001 for all). Although risks for abnormal Pap and HPV are modestly lower in WSW than in WSM, both are common in HIV-seropositive women regardless of sexual preference. Both WSW and WSM should be screened similarly.

Evolutionary analysis of neuraminidase gene of the novel avian influenza virus A/H7N9

Objective To investigate the evolutionary characteristics and important amino acid sites of the neuraminidase(NA) gene of the novel influenza virus A/H7N9 in 2013 epidemic.Methods The NA gene sequences of influenza virus A N9 subtype of different times and areas were downloaded from the database of The National Center for Biotechnology Information(NCBI) and The Global Initiative on Sharing All Influenza Data(GISAID).MEGA 5.05 and BioEdit softwares were used for phylogenetic tree construction and nucleotide/protein sequence analysis.Results The NA gene sequence of the novel influenza virus A/H7N9 in 2013 shared a 96% similarity with that of the H11N9 avian strain found in Czech Republic in 2010.There were 5 amino acid deletions in this novel influenza virus,and one of the new strains had a variation in potential enzymatic active sites.Conclusion The NA gene of this 2013 novel influenza virus might originate from the avian H11N9 strains detected in Czech Republic.The deletion of amino acid might result in human infection and high fatality rate.

High Rates of Incident and Prevalent Anal Human Papillomavirus Infection Among Young Men Who Have Sex With Men

There are few published estimates of anal human papillomavirus (HPV) infection rates among young men who have sex with men (YMSM). We estimated incidence and prevalence of type-specific anal HPV infection using clinician-collected anal swabs for HPV DNA testing obtained during a 1-year prospective study of 94 YMSM (mean age, 21 years) in Seattle. Seventy percent of YMSM had any HPV infection detected during the study, and HPV-16 and/or -18 were detected in 37%. The incidence rate for any new HPV infection was 38.5 per 1000 person-months and 15.3 per 1000 person-months for HPV-16/18; 19% had persistent HPV-16/18 infection. No participant tested positive for all 4 HPV types in the quadrivalent vaccine. The number of lifetime male receptive anal sex partners was significantly associated with HPV infection. The prevalence of HPV-16/18 was 6% among YMSM with a history of 1 receptive anal sex partner and 31% among YMSM with ≥ 2 partners. Although the high prevalence of HPV among YMSM highlights the desirability of vaccinating all boys as a strategy to avert the morbidity of HPV infection, most YMSM appear to remain naive to either HPV-16 or -18 well into their sexual lives and would benefit from HPV immunization.

Spatially Explicit Modeling of Schistosomiasis Risk in Eastern China Based on a Synthesis of Epidemiological, Environmental and Intermediate Host Genetic Data

Schistosomiasis japonica is a major parasitic disease threatening millions of people in China. Though overall prevalence was greatly reduced during the second half of the past century, continued persistence in some areas and cases of re-emergence in others remain major concerns. As many regions in China are approaching disease elimination, obtaining quantitative data on Schistosoma japonicum parasites is increasingly difficult. This study examines the distribution of schistosomiasis in eastern China, taking advantage of the fact that the single intermediate host serves as a major transmission bottleneck. Epidemiological, population-genetic and high-resolution ecological data are combined to construct a predictive model capable of estimating the probability that schistosomiasis occurs in a target area (“spatially explicit schistosomiasis risk”). Results show that intermediate host genetic parameters are correlated with the distribution of endemic disease areas, and that five explanatory variables—altitude, minimum temperature, annual precipitation, genetic distance, and haplotype diversity—discriminate between endemic and non-endemic zones. Model predictions are correlated with human infection rates observed at the county level. Visualization of the model indicates that the highest risks of disease occur in the Dongting and Poyang lake regions, as expected, as well as in some floodplain areas of the Yangtze River. High risk areas are interconnected, suggesting the complex hydrological interplay of Dongting and Poyang lakes with the Yangtze River may be important for maintaining schistosomiasis in eastern China. Results demonstrate the value of genetic parameters for risk modeling, and particularly for reducing model prediction error. The findings have important consequences both for understanding the determinants of the current distribution of S. japonicum infections, and for designing future schistosomiasis surveillance and control strategies. The results also highlight how genetic information on taxa that constitute bottlenecks to disease transmission can be of value for risk modeling.

Schistosoma haematobium in China, ex‐Africa: New Populations at Risk?

Schistosomiasis is an important parasitic disease affecting over 200 million individuals, with the majority of those affected in Africa.1 Imported cases of schistosomiasis have been reported among tourist travelers,2 immigrants,3 expatriates,4 Peace Corps volunteers,5 and military personnel6 with exposures to endemic areas of Africa or Asia. Reports of infections from travelers continue to provide an important indicator to unrecognized disease exposures as well as infections moving into new populations at risk. The function of travelers as sentinels for imported diseases has been extensively discussed.7 Sentinel surveillance networks such as GeoSentinel4 and TropNetEurop8 play a valuable role in providing data on travel‐associated exposures to schistosomiasis as well as on demographic characteristics of infected individuals. While Schistosoma mansoni and Schistosoma haematobium are the most common species involved in African schistosomiasis, in Asia, Schistosoma japonicum and Schistosoma mekongi are the predominant species found to cause disease. China has been endemic for S. japonicum during much of the past century, with over 1.6 million persons estimated to be infected in the first nationwide survey conducted in 1989,9 but with a strong national control program, the number of infected individuals was reduced by over 40%, to approximately 860,000 in the second nationwide survey in 1995.10 In contrast, the third nationwide survey in 2004 showed that human infection rates had increased by 4% in areas … Corresponding Author: Poh Lian Lim, MD, MPH, Department of Infectious Diseases, Institute of Infectious Disease & Epidemiology (IIDE), Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore. E‐mail: poh\_lian\_lim{at}ttsh.com.sg

OP030: The reported prevalence rates of oropharyngeal human papilloma virus infection by tissue type, detection technique and geography

Purpose The association of HPV with a distinct entity of oropharyngeal cancer is well documented by strong laboratory and epidemiologic evidence. Reported prevalence rates of oropharyngeal HPV infection is essential for the evaluation of the potential cost-effectiveness of vaccination and screening programmes. Materials and methods Literature search (English literature) of databases AMED, MEDLINE, EMBASE, BNI, PsychINFO (1985–present). Keywords used were human papilloma virus, oropharyngeal cancer, tonsil, tongue base tumours, United Kingdom. Results The currently available data on the prevalence of HPV infection in the oral cavity in the general population and the age and gender distribution of this infection is limited to small studies. Furthermore, the studies used a variety of sample types and different HPV detection techniques. Tonsil specimens using PCR: Between 0% and 16% (Klinkenberg 2010, Ernster 2009, Kim 2007, Sisk 2006, Ribeiro 2006, Mamas 2006, Chen 2005). In oropharyngeal exfoliated specimens: Between 0% and 31.6% (D’Souza 2007, Smith 2004, Summersgill 2001, Rintala 2006, Jennison 1990, Puranen 1996). By geographic region North America: Gillison et al. (2012) in JAMA has showed a low incidence in USA. In a cross-sectional study of 5579 participants aged 14–69 years, the overall prevalence of oropharyngeal HPV infection was 6.9%. Finland: Kero et al. (2012) undertook a 7 year prospective study on 131 males using oropharyngeal scrapings analysed with the Multimetrix kit. Point prevalence of oropharyngeal HPV infection fluctuated from 15.1% to 31.1%. Sweden: Du et al. (2012) found oropharyngeal HPV prevalence of 9.3% in 483 patients in a youth clinic. Pakistan: In Pakistan, oropharyngeal cavity HPV was found in 47 of 200 normal subjects (23.5%) using real-time PCR (Gickchi et al. 2012). Conclusion Reported prevalence rates of oropharyngeal HPV infection varies widely depending on the population studied and the technique used. Standardised detection techniques are required.

Assessment of Serosurveys for H5N1

It has been suggested that the true case-fatality rate of human H5N1 influenza infection is appreciably less than the figure of approximately 60% that is based on official World Health Organization (WHO)-confirmed case reports because asymptomatic cases may have been missed. A number of seroepidemiologic studies have been conducted in an attempt to identify such missed cases. We conducted a comprehensive literature review of all English-language H5N1 human serology surveys with detailed attention to laboratory methodology used (including whether investigators used criteria set by the WHO to define positive cases), laboratory controls used, and the clades/genotypes involved. Twenty-nine studies were included in the analysis. Few reported using unexposed control groups and one-third did not apply WHO criteria. Of studies that used WHO criteria, only 4 found any seropositive results to clades/genotypes of H5N1 that are currently circulating. No studies reported seropositive results to the clade 2/genotype Z viruses that have spread throughout Eurasia and Africa. This review suggests that the frequency of positive H5 serology results is likely to be low; therefore, it is essential that future studies adhere to WHO criteria and include unexposed controls in their laboratory assays to limit the likelihood of false-positive results.

High Rate of Multiple Concurrent Human Papillomavirus Infections among HIV-Uninfected South African Adolescents

The epidemiology and impact of multiple concurrent Human papillomavirus (HPV) infections on the natural history of cervical disease is uncertain, but could have significant implications for cervical cancer prevention and HPV vaccination strategies. A cross-sectional prevalence study was conducted to determine the overall prevalence of HPV and the rate of multiple concurrent HPV infections, in a cohort of sexually active HIV-uninfected South African adolescents. HPV genotyping was performed using the polymerase chain reaction. Overall prevalence of HPV was 64.1%. Multiple concurrent HPV infections were found in 43.6% of participants and 68% of HPV-infected participants. Non-vaccine high-risk HPV (HR-HPV) genotypes were found much more often than vaccine types (HPV16 and HPV18). Our cohort of young South African females was found to have a high overall prevalence of HPV and multiple concurrent HPV infections. Most HR-HPV infections found were genotypes other than HPV16 or HPV18.

Environmental factors associated with American cutaneous leishmaniasis in a new Andean focus in Colombia

To evaluate the environmental and ecological factors associated with Leishmania transmission and vector abundance in Chaparral, Tolima-Colombia. First, we compared the ecological characteristics, abundance of phlebotomies and potential reservoir hosts in the peridomestic environment (100 m radius) of randomly selected houses, between two townships with high and low cutaneous leishmaniasis incidence. Second, we examined peridomestic correlates of phlebotomine abundance in all 43 houses in the higher risk township. The high transmission township had higher coverage of forest (23%vs. 8.4%) and shade coffee (30.7%vs. 11%), and less coffee monoculture (16.8%vs. 26.2%) and pasture (6.3%vs. 12.3%), compared to the low transmission township. Lutzomyia were more abundant in the high transmission township 2.5 vs. 0.2/trap/night. Lutzomyia longiflocosa was the most common species in both townships: 1021/1450 (70%) and 39/80 (49%). Numbers of potential wild mammal reservoirs were small, although four species were found to be infected with Leishmania (Viannia) spp. In the high transmission township, the overall peridomiciliary capture rate of L. longiflocosa was 1.5/trap/night, and the abundance was higher in houses located nearer to forest (ρ = -0.30, P = 0.05). The findings are consistent with a domestic transmission cycle with the phlebotomies dependent on dense vegetation near the house.

Distribution and clinical features of Paragonimiasis skrjabini in Three Gorges Reservoir Region

Paragonimiasis has previously been reported in the Southwest Provinces of China, including Chongqing and Sichuan. The construction of Three Gorges Dam, which was begun in 1994, has resulted in substantial changes to the depth and the flow pattern of the Yangtze River. To investigate epidemiology of the paragonimiasis, 724 people aged 2–49years were selected and examined for Paragonimus infection by intradermal test (IDT), and enzyme-linked immunosorbent assay (ELISA). A survey of eating habits was conducted face-to-face in 5 endemic counties. Freshwater crabs were collected from seven sites in the 5 counties to determine the rate of infection with Paragonimus metacercariae. Additionally, we analyzed 213 case reports from the region dated 2006 to 2009. According to the survey results, the prevalence of Paragonimus skrjabini infection in freshwater crab was 39.65%, and the human infection rates detected by IDT and ELISA were 14.36% (104/724) and 7.46% (54/724), respectively. These results show that the Three Gorges Reservoir is still an area of high paragonimiasis endemicity. The water level of the Yangtze River has risen to 175m, and the area of water coverage in the region has increased to 1084km2. These conditions will favor the growth and expansion of the freshwater crab population.

Investigation of the Concurrent Emergence of Salmonella enteritidis in Humans and Poultry in British Columbia, Canada, 2008–2010

An increase in the rate of human infections with Salmonella enteritidis (SE) occurred between 2007 and 2010 in British Columbia (BC). During the same time period, an increase in SE from poultry-sourced isolates and increased clinical severity in poultry were also observed in BC. This article describes a multi-sectoral collaboration during a 3-year investigation, and the actions taken by public health and animal health professionals. Human cases were interviewed, clusters were investigated, and a case-control study was conducted. Environmental investigations were conducted in food service establishments (FSE). Suspect foods were tested. Laboratory data from poultry-sourced isolates were analysed. Five hundred and eighty-four human cases of SE with the same pulsed-field gel electrophoresis pattern were identified between May 2008 and August 2010. Seventy-three percentage of cases reported consumption of eggs. The odds of egg consumption were 2.4 times higher for cases than controls. Implicated FSE were found to use ungraded eggs, which had been distributed illegally. Investigation suggested that there were multiple suppliers of these eggs. Collaboration between public health and animal health professionals led to data sharing, improved understanding of SE, engagement with the poultry industry and public communication. Multi-disciplinary, multi-sectoral and multi-pronged investigations are recommended to identify the likely source of illness in large, protracted foodborne outbreaks caused by commonly consumed foods.

Demographic, Risk, and Spatial Factors Associated With Over-the-Counter Syringe Purchase Among Injection Drug Users

Since 2005, California law allowed over-the-counter (OTC) syringe sales pending local authorization. Although pharmacy sales of OTC syringes are associated with reduced injection-mediated risks and decreases in human immunodeficiency virus infection rates, little is known about the factors associated with syringe purchase among injection drug users (IDUs). Using a cross-sectional design, the authors applied targeted sampling to collect quantitative survey data from IDUs (n = 563) recruited in San Francisco, California, during 2008. They also compiled a comprehensive list of retail pharmacies, their location, and whether they sell OTC syringes. They used a novel combination of geographic information system and statistical analyses to determine the demographic, behavioral, and spatial factors associated with OTC syringe purchase by IDUs. In multivariate analyses, age, race, injection frequency, the type of drug injected, and the source of syringe supply were independently associated with OTC syringe purchases. Notably, the prevalence of OTC syringe purchase was 53% lower among African-American IDUs (adjusted prevalence ratio = 0.47, 95% confidence interval: 0.33, 0.67) and higher among injectors of methamphetamine (adjusted prevalence ratio = 1.35, 95% confidence interval: 1.07, 1.70). Two neighborhoods with high densities of IDUs had limited access to OTC syringes. Increased access to OTC syringes would potentially prevent blood-borne infectious diseases among IDUs.

Increased H1N1 Infection Rate in Children with Asthma

The 2009 H1N1 flu appeared to cause more severe cold symptoms during the 2009-2010 flu season. We evaluated H1N1 infections during peak viral season in children with and without asthma to determine whether the H1N1 infectivity rate and illness severity were greater in subjects with asthma. One hundred and eighty children, 4-12 years of age, provided eight consecutive weekly nasal mucus samples from September 5 through October 24, 2009, and scored cold and asthma symptoms daily. Viral diagnostics were performed for all nasal samples. One hundred and sixty-one children (95 with asthma, 66 without asthma) completed at least 6 of the 8 nasal samples. The incidence of H1N1 infection was significantly higher in children with asthma (41%) than in children without asthma (24%; odds ratio, 4; 95% confidence interval, 1.8-9; P < 0.001), but rates of human rhinovirus infection (90% each) and other viral infections (47 vs. 41%) were similar. In children with asthma, there was a nonsignificant trend for increased loss of asthma control during H1N1 infections compared with human rhinovirus infections (38 vs. 21%; odds ratio, 2.6; 95% confidence interval, 0.9-7.2; P = 0.07). During peak 2009 H1N1 flu season, children with asthma were infected almost twice as often with H1N1 compared with other respiratory viruses. H1N1 infection also caused increased severity of cold symptoms compared with other viral infections. Given the increased susceptibility of children with asthma to infection, these findings reinforce the need for yearly influenza vaccination to prevent infection, and raise new questions about the mechanism for enhanced susceptibility to influenza infection in asthma.

SEIR MODEL FOR TRANSMISSION OF DENGUE FEVER IN SELANGOR MALAYSIA

In this paper, we study a system of differential equations that models the population dynamics of SEIR vector transmission of dengue fever. The model studied breeding value based on the number of reported cases of dengue fever in Selangor because the state had the highest case in Malaysia. The model explains that maximum level of human infection rate of dengue fever achieved in a very short period. It is also revealed that there existed suitability result between theoretical and empirical calculation using the model. The result of SEIR model will hopefully provide an insight into the spread of dengue fever in Selangor Malaysia and basic form for modeling this area.

Development and evaluation of one-step rRT-PCR and immunohistochemical methods for detection of Rift Valley fever virus in biosafety level 2 diagnostic laboratories

Rift Valley fever virus (RVFV) is a zoonotic insect transmitted virus endemic to Africa and the Arabian Peninsula. Infection causes abortions and high mortality in newborn ruminants. The overall human infection rate is <1%; however, fatality rates in those with severe clinical disease have been reported as high as 29%. The potential of RVFV as a bioterrorism agent and/or being accidentally introduced into North America is widely recognized. Currently, regional veterinary biosafety level 2 (BSL-2) diagnostic laboratories lack safe, modern, validated diagnostic tests to detect RVFV. An existing one-step real-time RT-PCR (rRT-PCR) assay was modified for quick virus inactivation for use in BSL-2 laboratories, evaluated on serum and tissue samples from experimentally infected lambs and calves, and compared to virus isolation. Viremia was detected in all inoculated sheep with titers reaching 10(6.5) plaque forming units/ml, or up to 10(10) viral RNA copies/ml. Viremia in calves was lower and not detected in all inoculated animals; however, all animals became transiently febrile and were infected as determined by rRT-PCR of tissues. Virus was isolated from rRT-PCR-positive liver and/or spleen in 33% of lamb and 41% of calf samples between 2 and 7 days post inoculation. For RVFV antigen detection, reagents are typically produced at BSL-3Ag or BSL-4 conditions and require inactivation and safety testing for use outside of containment. In this study, antiserum against recombinant RVFV-nucleocapsid (N) was produced to develop an immunohistochemical (IHC) assay which was subsequently evaluated on formalin fixed lamb and calf tissues at BSL-2 laboratory conditions. Antigen was detected by IHC in 79% of rRT-PCR-positive sheep and 70% of rRT-PCR-positive calf tissues tested. Once validated and approved by national regulatory agencies, these assays can be safely produced and distributed to regional diagnostic laboratories, providing capacity for early detection of RVFV in suspected ruminant samples.

Self-Reported Risks for Multiple-Drug Resistance among New Tuberculosis Cases: Implications for Drug Susceptibility Screening and Treatment

BackgroundMultiple drug-resistance in new tuberculosis (TB) cases accounts for the majority of all multiple drug-resistant TB (MDR-TB) worldwide. Effective control requires determining which new TB patients should be tested for MDR disease, yet the effectiveness of global screening recommendations of high-risk groups is unknown.MethodsSixty MDR-TB cases with no history of previous TB treatment, 80 drug-sensitive TB and 80 community-based controls were recruited in Lima, Peru between August and December, 2008 to investigate whether recommended screening practices identify individuals presenting with MDR-TB. Odd ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression to study the association of potential risk factors with case/control variables.ResultsMDR-TB cases did not differ from drug-sensitive TB and community controls in rates of human immunodeficiency virus infection, reported hospital or prison visits in the 3 years prior to diagnosis. MDR-TB cases were more likely than drug-sensitive TB controls to have had a recent MDR-TB household contact (OR 4.66, (95% CI 1.56–13.87)); however, only 15 cases (28.3%) reported this exposure. In multivariate modeling, recent TB household contact, but not contact with an MDR-TB case, remained predictive of MDR-TB, OR 7.47, (95% CI 1.91–29.3). Living with a partner rather than parents was associated with a lower risk of MDR-TB, OR 0.15, (95% CI 0.04–0.51).ConclusionTargeted drug susceptibility testing (DST) linked to reported MDR-TB contact or other high-risk exposures does not identify the majority of new TB cases with MDR disease in Lima where it is endemic. All new TB cases should be screened with DST to identify MDR patients. These findings are likely applicable to other regions with endemic MDR-TB.

Distribution and larval habitats of Anopheles species in northern Gyeonggi Province, Republic of Korea

A total of 180 larval collection sites (e.g., rice paddies, marshes, ground pools, ponds, stream margins, and irrigation and drainage ditches) was surveyed within a 2 km radius from Warrior Base training area, 5 km south of Panmunjeom (Joint Security Area, demilitarized zone), Gyeonggi Province, Republic of Korea (ROK), from May through October, 2007 to characterize larval habitat distributions of members of the Anopheles Hyrcanus Group (An. sinensis, An. lesteri, An. pullus, An. belenrae, An. kleini, and An. sineroides). A total of 5,859 anopheline larvae was collected from 84.4% of the sites surveyed, of which 4,071 were identified to species by polymerase chain reaction (PCR) using the ribosomal DNA internal transcribed spacer 2 (rDNA ITS2). Anopheles sinensis (52.6%) was the most frequently collected, followed by An. kleini (29.4%), An. sineroides (9.8%), An. pullus (6.7%), An. belenrae (1.1%), and An. lesteri (0.5%). Anopheles pullus and An. kleini were collected in greater proportions in May and from May - July, respectively. Few An. sinensis were collected from May - June, but it was the predominant species collected by August, and accounted for >80% of all larvae from September - October. Anopheles kleini was found in all habitats sampled; however, it was collected most frequently in young growth rice paddies, while An. sinensis was collected more frequently in mature and post-harvest paddies. Anopheles pullus was associated with pre-cultivated rice paddies, including water-filled tire ruts left from the previous fall's harvest.