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Infectious Disease

Scarlet fever is a notifiable disease in Hong Kong for over 40 years. There was relatively low activity of scarlet fever until an outbreak in mid-2011 which resulted in two deaths and more than 1,500 cases. Scarlet fever incidence remained elevated since then with >10-fold increase comparing to that before the upsurge. Reemergence of scarlet fever was also reported in China in 2011 and the United Kingdom in 2014. We analyzed the patterns in scarlet fever incidence in Hong Kong using the notifiable disease surveillance data from 2005-2015.

Objective:

This study examined the epidemiology of scarlet fever in Hong Kong based on notifiable disease surveillance data, in a period where a 10-fold upsurge in scarlet fever incidence occurred. High risk groups and important factors associated with scarlet fever transmission were identified.

Submitted by elamb on

Different studies have shown that Streptococcal infections in adults are more common among older age, blacks, and underlying chronic medical conditions like diabetes, cardiovascular and kidney diseases. In specific, other studies have demonstrated that streptococcal pyogenes can cause severe illnesses and dramatic hospital outbreaks. Furthermore, community-acquired pneumonia studies had also suggested that cardiovascular disease, severe renal disease, chronic lung disease and diabetes were associated with increased odds of hospitalization.

Objective:

To study the factors associated with streptococcal infection that led to hospitalization in Houston, Texas for years 2015-2016

Submitted by elamb on

Each significant outbreak and epidemic raises questions that must be answered in order to better inform future preparedness and response efforts, such as:

  • What are the systems and resources needed to characterize an outbreak?
  • What systems and resources are needed to bring an outbreak to a close?

While we can anticipate these types of questions, the absence of dedicated mechanisms to record operational experiences and challenges can result in valuable, ephemeral data that are crucial for improving outbreak response not being consistently collected or analyzed. Participation in outbreaks by external experts can be instrumental in ensuring that this important operational information is documented, analyzed and shared with the broader public health community. There is a particular need for observers external to the response who can capture and analyze applied data about the operational response to outbreaks—eg, the systems and strategies involved in responding to the such events ”in order to improve our understanding of best practices for detecting and responding to these events. These can then be shared so that the entire public health community can access and incorporate lessons learned into their own preparedness and response plans. External observers can also help describe the important work performed by local responders during outbreaks and advocate for necessary preparedness and response program resources. The Outbreak Observatory is currently in a pilot phase and is looking for international and US partners who may be interested in collaborating with members of our team during their next outbreak response.

Objective:

The Outbreak Observatory (OO) aims to:

  • Strengthen outbreak/epidemic preparedness and response activities through real-time, one-the-ground observations and analyses ●Identify best practices based on operational experience that are broadly applicable across outbreak response agencies
  • Serve as an independent voice to advocate for policies that support preparedness and response activities based on expert assessment of the resources required to build and maintain necessary outbreak response capabilities Support local practitioners’ efforts to publish their experiences
  • Sharing the firsthand experience of responders is critical for building outbreak preparedness and response capacity, and OO will serve as a dedicated mechanism to collect, analyze and disseminate this information
Submitted by elamb on

The evolution of novel influenza viruses in humans is a bio- logical phenomenon that can not be stopped. All existing data suggest that vaccination against the morbidity and mortality of the novel influenza viruses is our best line of defence. Unfortunately, vaccination requires that the infectious agent to be quickly identified and a safe vaccine in large quantities is produced and administered. As was witnessed with the 2009 H1N1 influenza pandemic, these steps took a frustratingly long period during which the novel influenza virus continued its unstoppable and rapid global spreading. In addition to the different vaccination strategies ( e.g. random mass vaccination, age structured vaccination), isolation and quarantining of infected individuals is another effective method used by the public health agencies to control the spreading of infectious diseases. Isolation is effective against any infectious disease, however it can be very hard to detect infectious individuals in the population when: 1. Symptoms are ambiguous or easily misdiagnosed ( e.g. 2009 H1N1 influenza outbreak shared many symptoms with many other influenza like illnesses) 2. When the symptoms emerge after the individual become infectious.

Objective

The purpose of our work is to develop a system for automatic contact tracing with the goal of identifying individuals who are most likely infected, even if we do not have direct diagnostic information on their health status. Control of the spread of respiratory pathogens (e.g. novel influenza viruses) in the population using vaccination is a challenging problem that requires quick identification of the infectious agent followed by large-scale production and administration of a vaccine. This takes a significant amount of time. A complementary approach to control transmission is contact tracing and quarantining, which are currently applied to sexually transmitted diseases (STDs). For STDs, identifying the contacts that might have led to disease transmission is relatively easy; however, for respiratory pathogens, the contacts that can lead to transmission include a huge number of face-to-face daily social interactions that are impossible to trace manually.

 



 

Submitted by Magou on

Effective responses to epidemics of infectious diseases hinge not only on early outbreak detection, but also on an assessment of disease severity. In recent work, we combined previously developed ARI case-detection algorithms (CDA) [1] with text analyses of chest imaging reports to identify ARI patients whose providers thought had pneumonia. In this work, we asked if a surveillance system aimed at patients with pneumonia would outperform one that monitors the full severity spectrum of ARI.

Objective

To determine if influenza surveillance should target all patients with acute respiratory infections (ARI) or only track pneumonia cases.

 

Submitted by Magou on

Absenteeism has great advantages in promoting the early detection of epidemics1. Since August 2011, an integrated syndromic surveillance project (ISSC) has been implemented in China2. Distribution of the absenteeism generally are asymmetry, zero inflation, truncation and non-independence3. For handling these encumbrances, we should apply the Zero-inflated Mixed Model (ZIMM).

Objective

To describe and explore the spatial and temporal variability via ZIMM for absenteeism surveillance in primary school for early detection of infectious disease outbreak in rural China.

Submitted by Magou on

Because the dynamics and severity of influenza in the US vary each season, yearly estimates of disease burden in the population are essential to evaluate interventions and allocate resources. The CDC uses data from a national health-care based surveillance system and mathematical models to estimate the overall burden of disease in the general population. Over the past decade, crowd-sourced syndromic surveillance systems have emerged as a digital data source that collects health-related information in near real-time. These systems complement traditional surveillance systems by capturing individuals who do not seek medical care and allowing for a longitudinal view of illness burden. However, because not all participants report every week and participants are more likely to report when ill, the number of weekly reports is temporally and spatially inconsistent and the estimates of disease burden and incidence may be biased. In this study, we use data from Flu Near You (FNY), a participatory surveillance system based in the US and Canada1, to estimate and compare Influenza-like Illness (ILI) ARs using different approaches to adjust for reporting biases in participatory surveillance data.

Objective:

To estimate and compare influenza attack rates (AR) in the United States (US) using different approaches to adjust for reporting biases in participatory syndromic surveillance data.

Submitted by elamb on

Vietnam initiated the HSS system in 1994 in selected provinces with high HIV burden. The surveillance has two components: monitor HIV sero-prevalence and risk behaviors among key population including PWID. However, no VL data were collected among HIV infected people. In 2016, Vietnam piloted an added component of VL testing to the existing HSS system. The purpose was to test the feasibility of adding VL testing to the HSS so that VL data among PWID would be available. The pilot was conducted in two provinces in southern Vietnam-Ho Chi Minh City and Long An. It was expected that adding the VL testing to the existing HSS would also save resources and help monitor HIV viral transmission among PWID in the community regardless if they are currently on anti-retroviral therapy (ART).

Objective:

To share Vietnam's experiences piloting the integration of viral load (VL) testing into the national HIV sentinel surveillance (HSS) system to better understand the level of HIV viral transmission among people who inject drugs (PWID).

Submitted by elamb on

Cryptosporidiosis is a diarrheal disease caused by microscopic parasite Cryptosporidium. Modes of transmission include eating undercooked food contaminated with the parasite, swallowing something that has come into contact with human or animal feces, or swallowing pool water contaminated with the parasite. The disease is clinically manifested usually with chronic diarrhea and abdominal cramps. It is found to be more prevalent in immunocompromised patients like HIV and AIDS. Cryptosporidiosis usually causes potentially life-threatening disease in people with AIDS.

Objective:

To demonstrate the demographic and clinical distribution of reported Cryptosporidiosis cases in Houston, Texas, from 2013-2016

Submitted by elamb on

Nigeria is the only polio endemic country in Africa. Four (4) WPV1 cases were confirmed in 2013 after two years of silence. Nigeria has a strong polio programme characterized by innovative and forward driven strategies, despite several challenges of which surveillance is one of the driving forces. Near perfect surveillance core indicators reported over the past twelve (12) months across certain states and Local Government Areas (LGAs) were issues of concern, given security challenges among others. In August, 2017, we conducted a peer review evaluation of the reported high stool adequacy and Non-polio Acute Flaccid Paralysis (AFP) rates of the World Health Organisation (WHO) verified AFP cases, in order to estimate and establish concordance for both surveillance core indicators in Lafia and Nasarawa Egon LGAs in Nasarawa State.

Objective:

In August, 2017, we conducted a peer review evaluation of the reported high stool adequacy and Non-polio Acute Flaccid Paralysis (AFP) rates of the World Health Organisation (WHO) verified AFP cases, in order to estimate and establish concordance for both surveillance core indicators in Lafia and Nasarawa Egon LGAs in Nasarawa State.

Submitted by elamb on
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