云南省狂犬病病人和犬类感染狂犬病病毒及M基因序列分析

目的 调查云南省部分地区狂犬病病人和疫点犬群携带狂犬病病毒(rabies virus, RABV)状况及RABV膜基质蛋白(matrixprotein, M)基因序列分析,为狂犬病防控提供科学依据。方法 2008-2009年在云南省采集犬脑组织标本606份,狂犬病病人唾液8份,脑脊液1份,用直接免疫荧光试验检测RABV抗原,用RT-PCR检测RABV核酸,对阳性标本进行M基因序列测定和分析。结果 所有标本经检测,RABV抗原和/或核酸阳性16份,其中疫点扑杀的貌似健康犬脑组织3.10%(10/323),狂犬病病人唾液5份、脑脊液1份。狗肉餐馆屠宰犬的脑组织283份均为阴性。云南16株RABV的M基因核苷酸和氨基酸同源性分别为88.5%~100%和85.2%~99.5%。它们与中国人用疫苗株aG核苷酸和氨基酸同源性分别为83.9%~85.7%和82.3%~93.6%;与人用疫苗株CTN181核苷酸和氨基酸同源性分别为99%~99.7%和98.5%~99%。系统进化分析表明,云南16株RABV均属基因Ⅰ型并可分为进化Ⅰ和Ⅱ群并分别与泰国等东南亚国家和相邻省份流行株具有较近的亲缘关系。结论 云南省狂犬病流行与周边省份和东南亚地区的狂犬病传播扩散有一定关系;狂犬病疫点部分貌似健康犬携带RABV并具有传染源意义;云南狂犬病病毒株M基因与我国人用狂犬病疫苗CTN株的同源性和亲缘关系较近,但与aG株同源性存在。     

Whole Genome Sequencing and Phylogenetic Analysis of Rabies Viruses from Bats in Connecticut,USA, 2018–2019

We performed whole genome sequencing and genetic characterization of rabies viruses (RABV) detected in bats submitted to the Connecticut Veterinary Medical Diagnostic Laboratory (CVMDL) during 2018–2019. Among 88 bats submitted to CVMDL, six brain samples (6.8%, 95% confidence interval: 1.6% to 12.1%) tested positive by direct fluorescent antibody test. RABVs were detected in big brown bats (Eptesicus fuscus, n = 4), a hoary bat (Lasiurus cinereus, n = 1), and an unidentified bat species (n = 1). Complete coding sequences of four out of six detected RABVs were obtained. In phylogenetic analysis, the RABVs (18-62, 18-4347, and 19-2274) from big brown bats belong to the bats EF-E1 clade, clustering with RABVs detected from the same bat species in Pennsylvania and New Jersey. The bat RABV (19-2898) detected from the migratory hoary bat belongs to the bats LC clade, clustering with the eleven viruses detected from the same species in Arizona, Washington, Idaho, and Tennessee. The approach used in this study generated novel data regarding genetic relationships of RABV variants, including their reservoirs, and their spatial origin and it would be useful as reference data for future investigations on RABV in North America. Continued surveillance and genome sequencing of bat RABV would be needed to monitor virus evolution and transmission, and to assess the emergence of genetic mutations that may be relevant for public health.     

Importance of Cholera and Other Etiologies of Acute Diarrhea in Post-Earthquake Port-au-Prince,Haiti

We estimated the proportion of diarrhea attributable to cholera and other pathogens during the rainy and dry seasons in patients seen in two urban health settings: a cholera treatment center (CTC) and oral rehydration points (ORPs). During April 1, 2011–November 30, 2012, stool samples were collected from 1,206 of 10,845 patients who came to the GHESKIO CTC or to the community ORPs with acute diarrhea, cultured for Vibrio cholerae, and tested by multiplex polymerase reaction. Vibrio cholerae was isolated from 409 (41.8%, 95% confidence interval [CI] = 38.7–44.9%) of the 979 specimens from the CTC and in 45 (19.8%, 95% CI = 14.8–25.6%) of the 227 specimens from the ORPs. Frequencies varied from 21.4% (95% CI = 16.6–26.7%) during the dry season to 46.8% (95% CI = 42.9–50.7%) in the rainy season. Shigella, enterotoxigenic Escherichia coli, rotavirus, and Cryptosporidium were frequent causes of diarrhea in children less than five years of age.     

Dermatologic lesions in asymptomatic blood donors seropositive for human T cell lymphotropic virus type-1

Dermatologic manifestations are quite common in patients with adult T cell leukemia/lymphoma and myelopathy/tropical spastic paraparesis associated with infection with human T cell lymphotropic virus type-1 (HTLV-1). In this study, we evaluated the dermatologic lesions of eligible blood donors in the state of Minas Gerais in Brazil who were seropositive but asymptomatic for infection with HTLV-1. The study population was composed of 128 HTLV-1-seropositive individuals and 108 seronegative controls. All individuals underwent a dermatologic evaluation. Biopsy specimens were obtained from abnormal and normal skin samples of seropositive individuals in an attempt to detect HTLV-1 in tissue samples by a polymerase chain reaction. Dermatologic alterations were observed more frequently in the seropositive group (adjusted odds ratio [OR] = 8.77, 95% confidence interval [CI] = 4.11-18.71). The most common skin diseases were dermatophytoses (adjusted OR = 3.32, 95% CI = 1.50-7.35), seborrheic dermatitis (OR = 3.53, 95% CI = 0.67-24.66), and acquired ichthyosis (P = 0.001). Virus was detected more frequently in abnormal skin samples. Dermatologic lesions probably related to HTLV-1 infection were diagnosed in eligible blood donors who were infected with this virus, who were previously considered to be asymptomatic carriers of HTLV-1.     

Risk factors for malaria infection and anemia for pregnant women in the Sahel area of Bandiagara, Mali

Malaria infection and anemia during pregnancy are the primary causes of maternal and fetal morbidity and mortality. The aims of this study were to identify risk factors for malaria infection and to assess the relationship between malaria infection and anemia in pregnant women. Two cross-sectional surveys were conducted in September 1993 and then again in May 1994 (the end of the rainy and dry seasons respectively). A total of 235 pregnant women were randomly selected from both the rural and urban areas of Bandiagara, Mali. According to results from multivariate analysis, the risk of malaria infection was significantly higher during the rainy season (OR= 4.85, 95% CI 2.42-9.75) the first trimester of gestation (OR= 2.21, 95% CI 1.00-4.87, in younger women (OR= 2.48, 95% CI 1.19-5.16), and in women living in the rural area (2.49, 95% CI 0.99-6.27). The risk of anemia was also higher during the rainy season (OR= 1.93, 95% CI 1.10-3.39, in the rural area (OR= 3.55, 95% CI 1.46-8.62). The risk of anemia was lower during the first trimester of gestational age (OR= 0.45, 95% CI 0.22-0.92). The relationship between malaria infection and anemia also varied with season. During the rainy season, the risk for anemia was similar among malaria-infected and non-infected pregnant women. In contrast, the risk was higher among infected pregnant women during the dry season (OR= 3.43, 95% CI 1.09-10.07). In conclusion, the data suggest, that earlier gestation age, living in the rural area, and young age rather than parity are important risk factors for malaria infection in pregnant women. Further, malaria infection is strongly associated with anemia in pregnant women particularly during the dry season and is most likely the cause of anemia. Thus, control measures against malaria infection should target younger rural women in their first trimester of pregnancy.     

Rapid diagnosis of rabies in humans and animals by a dot blot enzyme immunoassay.

OBJECTIVES: The presently advocated tests for rapid diagnosis of rabies, such as the fluorescent antibody test (FAT) are expensive and require expertise to carry out and interpret the results. In this study, a simple direct dot blot enzyme immunoassay (DIA) has been developed and evaluated to detect the rabies antigen in brain specimens of animals and humans. The utility of this test in the ante-mortem diagnosis of human rabies has also been evaluated. METHODS: Brain homogenates of suspected rabid animals (n = 250), humans (n = 16) and clinical samples like saliva (n = 12) and cerebrospinal fluid (CSF) (n = 12) were directly spotted on polyvinylidene difluoride membrane (PVDF) and the absorbed rabies nucleoprotein antigen was detected using biotinylated antinucleoprotein antibody followed by treatment with streptavidin peroxidase conjugate and color development with diamino benzedine (DAB). Rabies-infected and normal mouse brain homogenates were used as positive and negative controls, respectively. The results of this test were evaluated with fluorescent antibody technique (for brain samples) and mouse inoculation test (for saliva and CSF samples). RESULTS: A distinct dark brown color was seen in the positive control and all positive samples, while there was no color development with either the negative control or the negative samples. The concordance between the fluorescent antibody test (FAT) and dot immunoassay was 98.4% for brain samples, 83.3% for saliva and 91.6% for CSF samples. The specificity of the test was found to be 100%. CONCLUSIONS: The dot blot enzyme immunoassay (DIA) test described here is a sensitive, specific and rapid test for the post-mortem diagnosis of rabies in animals and humans. The utility of this test for the ante-mortem diagnosis of rabies needs to be further evaluated.     

Soil contamination and infections by soil-transmitted helminths in an endemic village in southern Thailand

The aim of this study was to test the association between soil contamination and infection of the household members by soil-transmitted helminths in dry and rainy seasons. A lake-side community in southern Thailand with a population of 2,340 was studied twice, in the dry season and rainy season of 1995. Fifty households were randomly selected. Soil samples near the latrine, in the yard, at the foot-washing area and under the trees were taken and analysed for presence of helminthic eggs. All members of the selected household were interviewed and stool samples obtained. Age-adjusted odds ratios of presence of Ascaris and Trichuris eggs in the household soil for ascariasis and trichuriasis were 10.5 (95% CI 1.5-77.1) and 5.5 (95% CI 2.4-12.7) in dry season and 10.4 (95% CI 2.5-43.8) and 8.3 (95% CI 3.4-20.0) in rainy season. The levels of hookworm eggs detected in the soil were too low to test the association. Soil analysis for eggs of Ascaris and Trichuris may be used to predict infections among the household members but not that for hookworm.     

Interplay between rabies virus and the mammalian immune system

Rabies is a disease caused following infection of the brainby the rabies virus(RABV). The principle mechanism of transmission is through a bite wound. The virus infects peripheral nerves and moves to the central nervous system(CNS). There appears to be little involvement of other organ systems and little detectable immune stimulation prior to infection of the CNS. This failure of the mammalian immune system to respond to rabies virus infection leads, in the overwhelming majority of cases, to death of the host. To some extent, this failure is likely due to the exclusive replication of RABV in neurons and the limited ability to generate, sufficiently rapidly, an anti-viral antibody response in situ. This is reflected in the ability of post-exposure vaccination, when given early after infection, to prevent disease. The lack of immune stimulation during RABV infection preceding neural invasion is the Achilles heel of the immune response. Whilst many viruses infect the brain, causing encephalitis and neuronal deficit, none are as consistently fatal to the host as RABV. This is in part due to prior replication of many viruses in peripheral, non-neural tissue by other viruses that allows timely activation of the immune response before the host is overwhelmed. Our current understanding of the correlates of protection for rabies suggests that it is the action of neutralising antibodies that prevent infection and control spread of RABV. Furthermore, it tells us that the induction of immunity can protect and understanding how and why this happens is critical to controlling infection. However, the paradigm of antibody development suggests that antigen presentation overwhelmingly occurs in lymphoid tissue(germinal and non-germinal centres) and these are external to the CNS. In addition, the blood-brain-barrier may provide a block to the delivery of immune effectors(antibodies/plasma B-cells) entering where they are needed. Alternatively, there may be insufficient antigen exposure after natural infection to mount an effective response or the virus actively suppresses immune function. To improve our ability to treat this fatal infection it is imperative to understand how immunity to RABV develops and functions so that parameters of protectionare better defined.     

Field performance of VAQTA (inactivated, purified hepatitis a vaccine) in Chinese children in Jiangsu

In Jiangsu, 30% of children between the ages of 5 and 8 years test seropositive for hepatitis A. The safety, tolerability, and immunogenicity of a 2-dose regimen (0, 6 months) of VAQTA (0.5 ml of 25U) administered IM in 50 healthy children aged 5 to 8 years without prior serological screening was evaluated. Blood samples were collected prior to the first dose and after each additional dose of VAQTA to determine the initial anti-HAV serostatus and response rates to the vaccine. Twelve children (24%) were initially seropositive and 38 (76%) were initially seronegative. Four weeks after the primary dose of VAQTA, 34 of the 38 subjects (89.5%, 95% CI 75 to 97) were anti-HAV seropositive. The geometric mean titer was 33.1 mIU/ml (95% CI 22.4 to 49.0). After the booster dose at 6 months, all the subjects were seropositive (37/37), giving a seroconversion of 100% (95% CI: 90, 100). The geometric mean titer was 7585.8 mIU/ml (95% CI: 5623.4 to 10,471.3). Adverse experiences were generally mild and transient. Results of this study are consistent with results from a previous double-blind randomized trial of this vaccine and confirm that VAQTA is highly immunogenic, and generally well-tolerated.     

Rabies Prophylactic and Treatment Options: An In Vitro Study of siRNA- and Aptamer-Based Therapeutics

If the goal of eliminating dog-mediated human rabies by 2030 is to be achieved, effective mass dog vaccination needs to be complemented by effective prophylaxis for individuals exposed to rabies. Aptamers and short-interfering RNAs (siRNAs) have been successful in therapeutics, but few studies have investigated their potential as rabies therapeutics. In this study, siRNAs and aptamers—using a novel selection method—were developed and tested against rabies virus (RABV) in a post-infection (p.i.) scenario. Multiple means of delivery were tested for siRNAs, including the use of Lipofectamine and conjugation with the developed aptamers. One siRNA (N53) resulted in an 80.13% reduction in viral RNA, while aptamer UPRET 2.03 demonstrated a 61.3% reduction when used alone at 2 h p.i. At 24 h p.i., chimera UPRET 2.03-N8 (aptamer-siRNA) resulted in a 36.5% inhibition of viral replication. To our knowledge, this is the first study using siRNAs or aptamers that (1) demonstrated significant inhibition of RABV using an aptamer, (2) tested Lipofectamine RNAi-Max as a means for delivery, and (3) produced significant RABV inhibition at 24 h p.i. This study serves as a proof-of-concept to potentially use aptamers and siRNAs as rabies immunoglobulin (RIG) replacements or therapeutic options for RABV and provides strong evidence towards their further investigation.     

Simian virus 40 in human cancers

BACKGROUND: Many studies have reported the presence of simian virus 40 (SV40) deoxyribonucleic acid (DNA) or protein in human brain tumors and bone cancers, malignant mesothelioma, and non-Hodgkin's lymphoma. However, the small samples and lack of control groups in some reports have made it difficult to assess their reliability. METHODS: Studies were included in this analysis if they met the following criteria: original studies of patients with primary brain tumors and bone cancers, malignant mesothelioma, or non-Hodgkin's lymphoma; the investigation of SV40 was performed on primary cancer specimens; the analysis included a control group; and the same technique was used for cases and controls. Included reports were published from 1975 to 2002. RESULTS: Thirteen studies fulfilled the criteria for the investigation of primary brain cancers (661 tumors and 482 control samples). Specimens from patients with brain tumors were almost four times more likely to have evidence of SV40 infection than were those from controls (odds ratio [OR] = 3.9; 95% confidence interval [CI]: 2.6 to 5.8). The association was even stronger for mesothelioma (OR = 17; 95% CI: 10 to 28; based on 15 studies with 528 mesothelioma samples and 468 control samples) and for bone cancer (OR = 25; 95% CI: 6.8 to 88; based on four studies with 303 cancers and 121 control samples). SV40 DNA was also more frequent in samples from patients with non-Hodgkin's lymphoma (OR = 5.4; 95% CI: 3.1 to 9.3; based on three studies with 301 cases and 578 control samples) than from controls. CONCLUSION: These results establish that SV40 is associated significantly with brain tumors, bone cancers, malignant mesothelioma, and non-Hodgkin's lymphoma. Studies are needed to assess current prevalence of SV40 infections.     

福建省狂犬病毒的N基因序列分析

目的了解福建省狂犬病毒流行毒株的基因分型和遗传进化关系,以及流行毒株与疫苗株在N基因核苷酸和氨基酸水平的差异。方法采集福建省不同时间、不同地区的犬脑组织标本共89份,通过RT-nested-PCR扩增、纯化、克隆、测序,获得19条包含N基因全长的序列,采用生物学软件进行序列整理分析。结果根据N基因核苷酸和推导的氨基酸的同源性,把福建省已知狂犬病毒分为3个群组,群组间具有显著的地域分布特征,各群组内部N基因核苷酸和氨基酸同源性分别在99.7%～100%和98.9%～100%之间,群组间N基因核苷酸和氨基酸同源性在86.4%～89.3%和95.3%～98.4%之间。福建省狂犬病毒的流行毒株与目前使用的各种疫苗株N基因序列同源性在86.5%～98.9%之间。结论福建省境内存在表观健康犬携带狂犬病毒现象,福建省已知狂犬病毒流行毒株均属于基因I型,可分为3个群组。从N基因序列的分析上看,我省目前使用疫苗能有效地保护流行毒株的感染。     

Seroprevalence of varicella zoster virus in Colombo district,Sri Lanka

Objective: To determine the seroprevalence of varicella zoster virus(VZV) antibodies among the population residing in the Colombo district of Sri Lanka. Methods: A cross-sectional population-based study was conducted which included 1 258 participants. Blood samples were collected and questionnaires administered to obtain sociodemographic information and history of varicella and/or herpes zoster. Serum samples were assayed for VZV IgG antibodies using a commercial enzyme-linked immunosorbent assay kit. Results: Overall, the seroprevalence was 54.2%(95% CI= 51.5% 57.0%). Children below 1 year of age were seronegative, and only about 20.0% of children between 1 and 10 years of age were seropositive. Seropositivitiy increased with age and by the age of 40 years 74.3% were seropositive. Among women of childbearing age, the overall seroprevalence was about 62.0%(95% CI = 57.7%-66.1%) but was low 37.0% in the 15-19 age group. Conclusion: In this population, 45.8% lacked natural immunity against varicella. Of women of childbearing age, 39.9% lacked immunity and in the subgroup of women 15-19 years of age, 63.0% women lacked immunity. In light of the country's success with the control and high coverage of other vaccine preventable diseases and that the vaccine is available in the private sector, the inclusion of varicella vaccine in the national immunization program may be considered.     

Rabies in wildlife in Latvia

In the Baltic States, lyssaviruses are often detected in wildlife and presumed to constitute an important public health hazard. In order to decrease rabies incidence and eradicate wildlife reservoirs, a national rabies eradication program has been in place. Since 1970 a vaccination program in dogs and cats has been executed, and in 1991 oral vaccination of foxes was started. However, due to an insufficient budget, the latter was not done regularly and nationwide before 2000. Now, the program in force consists of compulsory vaccination of all dogs and cats, and a tetracycline marker vaccine oral vaccination program of foxes in the whole country. In 2001, 151 of 285 (53%) fox jaws were tested positive for tetracycline. All animals showing rabies-like symptoms were killed and tested for rabies. In this way, 250-400 cases of rabies per year were diagnosed in wildlife. To molecularly characterize the prevalent lyssaviruses in wildlife, lyssavirus RNA of 25 recent rabies positive samples, collected in the year 1999, was amplified by RT-PCR. Direct sequencing of the RT-PCR-amplified products of the virus' nucleoprotein encoding region and subsequent sequence analyses resulted in a 99.3-100% homology between isolates and a 99.0-100% similarity with a 1995 genotype I, classical rabies virus (RABV) raccoon dog isolate from Estonia. These results confirmed that RABV is endemic in wildlife in Latvia and should be considered a serious public health threat. To successfully eradicate the wildlife reservoirs, the national rabies eradication program must be continued, and it may need to be intensified.     

狂犬病病毒的功能蛋白研究进展

狂犬病(Rabies)是由狂犬病毒(Rabies virus,RABV)引起的一种高度致死性中枢神经系统感染的疾病。RABV主要由5个功能蛋白组成,各个蛋白在致病性方面均发挥重要的作用。本文就狂犬病病毒各个功能蛋白的国内外研究进展进行综述,从而加深对于RABV致病性的了解。     

Evaluation of Two Real-Time,TaqMan Reverse Transcription-PCR Assays for Detection of Rabies Virus in Circulating Variants from Argentina: Influence of Sequence Variation

In rabies diagnosis, it is essential to count on a rapid test to give a quick response. The combined sensitivity and robustness of the TaqMan RT-PCR assays (qRT-PCR) have made these methods a valuable alternative for rabies virus (RABV) detection. We conducted a study to compare the applicability of two widely used qRT-PCR assays targeting the nucleoprotein gene (LysGT1 assay) and leader sequences (LN34 qRT-PCR assay) of RABV genomes, in all variants circulating in Argentina. A total of 44 samples obtained from bats, dogs, cattle, and horses, that were previously tested for rabies by FAT and conventional RT-PCR, were used in the study. All variants were successfully detected by the pan-lyssavirus LN34 qRT-PCR assay. The LysGT1 assay failed to detect three bat-related variants. We further sequenced the region targeted by LysGT1 and demonstrated that the presence of three or more mismatches with respect to the primers and probe sequences precludes viral detection. We conclude that the LysGT1 assay is prone to yield variant-dependent false-negative test results, and in consequence, the LN34 assay would ensure more effective detection of RABV in Argentina.     

Cervical shedding of herpes simplex virus in human immunodeficiency virus-infected women: effects of hormonal contraception, pregnancy, and vitamin A deficiency

Genital shedding of herpes simplex virus (HSV) results in frequent transmission of infection to sexual partners and neonates. In a cross-sectional study, cervical shedding of HSV DNA was detected in 43 (17%) cervical swab samples from 273 women seropositive for HSV-1, HSV-2, and human immunodeficiency virus type 1 (HIV-1). Cervical shedding of HSV was significantly associated with oral contraception (adjusted odds ratio [aOR], 4.5; 95% confidence interval [CI], 1.7-12.2), use of depo-medroxyprogesterone acetate (aOR, 3.2; 95% CI, 1.3-7.7), and pregnancy (aOR, 7.9; 95% CI, 2.0-31.7). In the subgroup of women who were not pregnant and not using hormonal contraception (n=178), serum vitamin A was highly predictive of cervical HSV shedding: concentrations indicating severe deficiency, moderate deficiency, low-normal, and high-normal status were associated with 29%, 18%, 8%, and 2% prevalences of cervical HSV shedding, respectively (linear trend, P=.0002). Several factors appear to influence HSV reactivation in HIV-1 seropositive women.     

Helicobacter pylori and CagA seropositivity and its association with gastric and oesophageal carcinoma

OBJECTIVE: Helicobacter pylori infection is an established risk factor for non-cardia gastric adenocarcinoma. Infection with H. pylori strains harbouring the cagA pathology island may augment this association. H. pylori infection may at the same time reduce the risk for oesophageal carcinoma. However, prospective data on the association between CagA seropositivity and gastric or oesophageal carcinomas are limited. The purpose of this study was to investigate whether CagA seropositivity among H. pylori seropositive subjects is associated with gastric or oesophageal carcinomas. MATERIAL AND METHODS: A nested case-control study was performed in the Malm? Preventive Medicine cohort consisting of 32,906 middle-aged subjects. Tumour cases were identified by the Swedish National Cancer Registry. The Western blot method Helicoblot 2.1 was used to detect H. pylori and CagA seropositivity. RESULTS: Non-cardia gastric adenocarcinoma was associated with H. pylori seropositivity, odds ratio 17.8 (95% CI: 4.2-74.8; 67 cases). The odds ratio for CagA seropositivity among H. pylori seropositive subjects was 9.7 (95% CI: 1.5-infinity). No significant associations were found between cardia gastric adenocarcinoma and H. pylori or CagA seropositivity among H. pylori seropositive subjects; odds ratios were 1.5 (95% CI: 0.51-4.8) and 2.7 (95% CI: 0.38-infinity), respectively (24 cases). Oesophageal adenocarcinoma and oesophageal squamous cell carcinoma were not significantly associated with H. pylori seropositivity or with CagA seropositivity among H. pylori seropositive subjects; the odds ratios associated with oesophageal adenocarcinoma were 0.46 (95% CI: 0.07-2.6) and 0.38 (95% CI: 0.02-24), respectively. Corresponding odds ratios for oesophageal squamous cell carcinoma were 0.44 (95% CI: 0.15-1.2; 37 cases) and 2.0 (95% CI: 0.24-infinity), respectively. CONCLUSIONS: CagA seropositivity among H. pylori seropositive subjects is a risk factor for non-cardia gastric adenocarcinoma.