Water-borne protozoa parasites: The Latin American perspective

Health systems, sanitation and water access have certain limitations in nations of Latin America (LA): typical matters of developing countries. Water is often contaminated and therefore unhealthy for the consumers and users. Information on prevalence and detection of waterborne parasitic protozoa are limited or not available in LA. Only few reports have documented in this field during the last forty years and Brazil leads the list, including countries in South America and Mexico within Central America region and Caribbean islands. From 1979 to 2015, 16 outbreaks of waterborne-protozoa, were reported in Latin American countries. T. gondii and C. cayetanensis were the protozoa, which caused more outbreaks and Giardia spp. and Cryptosporidium spp. were the most frequently found protozoa in water samples. On the other hand, Latin America countries have not got a coherent methodology for detection of protozoa in water samples despite whole LA is highly vulnerable to extreme weather events related to waterborne-infections; although Brazil and Colombia have some implemented laws in their surveillance systems. It would be important to coordinate all surveillance systems in between all countries for early detection and measures against waterborne-protozoan and to establish effective and suitable diagnosis tools according to the country’s economic strength and particular needs.     

Detection and analysis of recombination in GII.4 norovirus strains causing gastroenteritis outbreaks in Alberta

Recombination is an important mechanism generating genetic diversity in norovirus (NoV) that occurs commonly at the NoV polymerase-capsid (ORF1/2) junction. The genotyping method based on partial ORF2 sequences currently used to characterize circulating NoV strains in gastroenteritis outbreaks in Alberta cannot detect such recombination events and provides only limited information on NoV genetic evolution. The objective of this study was to determine whether any NoV GII.4 strains causing outbreaks in Alberta are recombinants. Twenty stool samples collected during outbreaks occurring between July 2004 and January 2012 were selected to include the GII.4 variants Farmington Hills 2002, Hunter 2004, Yerseke 2006a, Den Haag 2006b, Apeldoorn 2007, New Orleans 2009, and Sydney 2012 based on previous NoV ORF2-genotyping results. Near full-length NoV genome sequences were obtained, aligned with reference sequences from GenBank and analyzed with RDPv4.13. Two sequences corresponding to Apeldoorn 2007, and Sydney 2012 were identified as recombinants with breakpoints near the ORF1/2 junction and putative parental strains as previously reported. We also identified, for the first time, a non-recombinant sequence resembling the ORF2–3 parent of the recombinant cluster Sydney 2012 responsible for the most recent pandemic. Our results confirmed the presence of recombinant NoV GII.4 strains in Alberta, and highlight the importance of including additional genomic regions in surveillance studies to trace the evolution of pandemic NoV GII.4 strains.     

2003-2004年福建省流感暴发监测分析

[目的]了解福建省流感流行动态,探索流行规律,为流感防治提供科学依据.[方法]进行流行病学调查,用MDCK细胞和鸡胚进行病毒分离,用血凝抑制实验对病毒株进行分型鉴定及血清流感抗体测定.[结果]2003-2004年我省共报告局部暴发流感疫情49起,发病3 088例,共采集咽拭子或漱口液标本360份,分离流感病毒阳性率25.8%(93/360).其中甲3型88株(94.6%),乙型5株(5.3%).2年共采集流感样患者急性期、恢复期血清各221份,其中甲3型抗体4倍增长阳性率58.4%(129/221),乙型抗体4倍增长阳性0.5%(11/221).[结论]引起福建省2003-2004年流感暴发的毒株以甲3型为主,暴发的时间主要集中在每年的4月和9月.     

Predicting localised measles outbreak potential in Australia

IntroductionAustralia has achieved measles elimination as announced in March 2014 by the WHO Western Pacific Regional Committee, based on several lines of evidence. However, despite strong national evidence for elimination, there remains substantial regional variation in vaccine coverage, has resulted in recent outbreaks and potential for increased frequency in the future.MethodsIn this study, we apply a multiple cohort model of measles immunity, stratified by age and local geographic area to predict trends in the measles reproduction number R. In addition, we use branching process models of outbreak risks to predict state-level probabilities of the occurrence of measles outbreaks over the next 20 years.ResultsOur results suggest increasing risks of large measles outbreaks over this period, in particular in the states of Queensland and New South Wales. In addition, there is wide variation in predicted R values by smaller geographic areas, although uncertainty in age-specific immunity limits the precision of our results.DiscussionOur predictions align with observed outbreaks in Australian states and suggest our approach to determining future outbreak risks could be applied more widely in elimination or near-elimination settings.     

Poor adherence to population-based vaccination in two counties after meningococcal B:14:P1.7,16 outbreak: an illustration of the growing vaccine hesitancy in France

Background

Neisseria meningitidis is a virulent bacteria provoking outbreaks of invasive meningococcal disease (IMD) that authorities may try to control with population-based vaccinations. Such campaigns are most often thoroughly followed. We assess the response of poor adherence during a population-based vaccination after a meningococcal B:14:P1.7,16 outbreak.

Evaluation of hepatitis B vaccine immunogenicity among older adults during an outbreak response in assisted living facilities

Background

During the past decade, in the United States, an increasing number of hepatitis B outbreaks have been reported in assisted living facilities (ALFs) as a result of breaches in infection control practices. We evaluated the seroprotection rates conferred by hepatitis B vaccine among older adults during a response to an outbreak that occurred in multiple ALFs and assessed the influence of demographic and clinical factors on vaccine response.

Methods

Residents were screened for hepatitis B and C infection prior to vaccination and susceptible residents were vaccinated against hepatitis B with one dose of 20 μg Engerix-B™ (GSK) given at 0, 1, and 4 months. Blood samples were collected 80-90 days after the third vaccine dose to test for anti-HBs levels.

Results

Of the 48 residents who had post-vaccination blood specimens collected after the third vaccine dose, 16 (33.3%) achieved anti-HBs concentration ≥10 mIU/mL. Age was a significant determinant of seroprotection with rates decreasing from 88% among persons aged ≤60 years to 12% among persons aged ≥90 years (p = 0.001). Geometric mean concentrations were higher among non-diabetic than diabetic residents, however, the difference was not statistically significant (5.1 vs. 3.8 mIU/mL, p = 0.7).

Conclusions

These findings highlight that hepatitis B vaccination is of limited effectiveness when administered to older adults. Improvements in infection control and vaccination at earlier ages might be necessary to prevent spread of infection in ALFs.     

Epidemiology of Campylobacter jejuni outbreak in a middle school in Incheon, Korea

On July 6, 2009, an outbreak of gastroenteritis occurred among middle school students in Incheon. An investigation to identify the source and describe the extent of the outbreak was conducted. A retrospective cohort study among students, teachers, and food handlers exposed to canteen food in the middle school was performed. Using self-administered questionnaires, information was collected concerning on symptoms, days that canteen food was consumed, and food items consumed. Stool samples were collected from 66 patients and 11 food handlers. The catering kitchen was inspected and food samples were taken. Of the 791 people who ate canteen food, 92 cases became ill, representing an attack rate of 11.6%. Thirty-one (40.3%) of the 77 stool specimens were positive for Campylobacter jejuni. Interviews with kitchen staff indicated the likelihood that undercooked chicken was provided. This is the first recognized major C. jejuni outbreak associated with contaminated chicken documented in Korea.