Challenges of establishing routine influenza sentinel surveillance in Ethiopia, 2008-2010.

Ethiopia launched influenza surveillance in November 2008. By October 2010, 176 patients evaluated at 5 sentinel health facilities in Addis Ababa met case definitions for influenza-like illness or severe acute respiratory illness (SARI). Most patients (131 [74%]) were children aged 0-4 years. Twelve patients (7%) were positive for influenza virus. Most patients (109 [93%]) were aged <5 years, of whom only 3 (2.8%) had laboratory-confirmed influenza. Low awareness of influenza by healthcare workers, misperceptions regarding case definitions, and insufficient human resources at sites could have potentially led to many missed cases, resulting in suboptimal surveillance.

Increase in rates of hospitalization due to laboratory-confirmed influenza among children and adults during the 2009-10 influenza pandemic.

BACKGROUND: The Emerging Infections Programs (EIP) network has conducted population-based surveillance for hospitalizations due to laboratory-confirmed influenza among children since 2003, with the network expanding in 2005 to include adults. METHODS: From 15 April 2009 through 30 April 2010, the EIP conducted surveillance among 22.1 million people residing in 10 states. Incidence rates per 100 000 population were calculated using US Census Bureau data. Mean historic rates were calculated on the basis of previously published and unpublished EIP data. RESULTS: During the 2009 pandemic of influenza A virus subtype H1N1 infection, rates of hospitalizations due to laboratory-confirmed influenza were 202, 88, 49, 31, 27, 36, 28, and 27 episodes per 100 000 among persons aged <6 months, 6-23 months, 2-4 years, 5-17 years, 18-49 years, 50-64 years, 65-74 years, and ≥75 years, respectively. Comparative mean rates from previous influenza seasons during which EIP conducted surveillance were 153, 53, 20, 6, 4, 8, 20, and 56 episodes per 100 000 among persons aged <6 months, 6-23 months, 2-4 years, 5-17 years, 18-49 years, 50-64 years, 65-74 years, and ≥75 years, respectively. CONCLUSIONS: During the pandemic, rates of hospitalization due to laboratory-confirmed influenza among individuals aged 5-17 years and 18-49 years increased 5-fold and 6-fold, respectively, compared with mean rates from previous influenza seasons. Hospitalization rates for other pediatric and adult age groups increased, compared with mean rates from previous influenza seasons, whereas the rate among individuals aged ≥75 years decreased.

2009 Pandemic influenza A (H1N1) deaths among children--United States, 2009-2010.

The 2009 pandemic influenza A (H1N1) (pH1N1) virus emerged in the United States in April 2009 (1) and has since caused significant morbidity and mortality worldwide (2-6). We compared pandemic influenza A (H1N1) (pH1N1)-associated deaths occurring from 15 April 2009 through 23 January 2010 with seasonal influenza-associated deaths occurring from 1 October 2007 through 14 April 2009, a period during which data collected were most comparable. Among 317 children who died of pH1N1-associated illness, 301 (95%) had a reported medical history. Of those 301, 205 (68%) had a medical condition associated with an increased risk of severe illness from influenza. Children who died of pH1N1-associated illness had a higher median age (9.4 vs 6.2 years; P<.01) and longer time from onset of symptoms to death (7 vs 5 days, P<.01) compared with children who died of seasonal influenza-associated illness. The majority of pediatric deaths from pH1N1 were in older children with high-risk medical conditions. Vaccination continues to be critical for all children, especially those at increased risk of influenza-related complications.

Invasive Haemophilus influenzae disease in Utah children: an 11-year population-based study in the era of conjugate vaccine.

BACKGROUND: The incidence of invasive Haemophilus influenzae infection decreased dramatically since the introduction of the H. influenzae serotype b (Hib) conjugate vaccine. H. influenzae invasive disease continues to occur and cause significant morbidity and mortality in children aged <5 years. We aimed to report the epidemiology and serotypes of invasive H. influenzae disease in children from Utah in the post-Hib vaccine era. METHODS: We identified all cases of invasive H. influenzae disease, defined as H. influenzae isolated from a sterile site, during the period 1998-2008 among children aged <18 years who were living in Utah. RESULTS: We identified 91 cases of invasive H. influenzae disease in children. Children aged <5 years accounted for 78 cases (86%). H. influenzae serotype a (Hia) was the most common serotype (22 cases), representing 28% of all cases of invasive disease among children aged <5 years. The majority (15 cases [93%]) of Hib disease cases occurred among children aged <5 years and accounted for 18% of all cases of H. influenzae invasive disease in this age group. The mean incidence of Hia disease increased from 0.8 cases per 100,000 child-years in 1998 to 2.6 cases per 100,000 child-years in 2008. The incidence of Hib disease among children aged <5 years remained steady at 0.5 cases per 100,000 child-years. Bacteremia accounted for 61% of all cases of invasive disease. One-half (13 of 26) of cases of H. influenzae meningitis were due to Hia. CONCLUSIONS: H. influenzae continues to cause invasive disease in Utah children. Hia is the primary cause of the overall increased incidence of invasive H. influenzae disease and leads to disease similar to Hib. Isolated cases of Hib disease demonstrate a continued reservoir. The success of the Hib conjugate vaccine may therefore be vulnerable to vaccine shortages and refusal of vaccination.

Relationships between body mass indices and surgical replacements of knee and hip joints.

BACKGROUND: Osteoarthritis is both the most common form of arthritis and the most common reason for joint replacement surgery. Obese persons are believed to be more likely to develop generalized osteoarthritis that leads not only to knee but also to hip joint replacement surgeries. We hypothesized that obesity is also a risk for partial joint replacements and surgical revisions. METHODS: A frequency-matched case-control study was conducted in Utah. Between 1992 and 2000, 840 hip and 911 knee joint replacement surgery patients, aged 55 to 74 years, were included in this study. Cases were randomly matched to 5578 controls, defined as Utah residents enrolled in a cancer screening trial. Odds ratios (ORs) were calculated using ICD-9 (International Classification of Diseases, 9th revision) procedural codes and body mass index (BMI) groups. RESULTS: There was a strong association between increasing BMI and both total hip and knee replacement procedures. In males, the highest OR was for those weighing 37.50 to 39.99 kg/m(2) (total hip: OR=9.37, 95% confidence interval [CI] 2.64-33.31; total knee: OR=16.40; 95% CI 5, 19-51.86). In females, the highest OR was for those weighing > or =40 kg/m(2) (total hip: OR=4.47; 95% CI, 2.13-9.37; total knee: OR=19.05; 95% CI, 9.79-37.08). There were slight gender-specific differences in risk found for partial hip replacement procedures. Unexpectedly, no statistically significant association was found between obesity and the risk for hip or knee revision procedures. CONCLUSIONS: While there is an association between obesity and hip and knee joint replacement surgeries, obesity does not appear to confer an independent risk for hip or knee revision procedures.

Prevalence of 2009 pandemic influenza A (H1N1) virus antibodies, Tampa Bay Florida--November-December, 2009.

BACKGROUND: In 2009, a novel influenza virus (2009 pandemic influenza A (H1N1) virus (pH1N1)) caused significant disease in the United States. Most states, including Florida, experienced a large fall wave of disease from September through November, after which disease activity decreased substantially. We determined the prevalence of antibodies due to the pH1N1 virus in Florida after influenza activity had peaked and estimated the proportion of the population infected with pH1N1 virus during the pandemic. METHODS: During November-December 2009, we collected leftover serum from a blood bank, a pediatric children's hospital and a pediatric outpatient clinic in Tampa Bay Florida. Serum was tested for pH1N1 virus antibodies using the hemagglutination-inhibition (HI) assay. HI titers ≥40 were considered seropositive. We adjusted seroprevalence results to account for previously established HI assay specificity and sensitivity and employed a simple statistical model to estimate the proportion of seropositivity due to pH1N1 virus infection and vaccination. RESULTS: During the study time period, the overall seroprevalence in Tampa Bay, Florida was 25%, increasing to 30% after adjusting for HI assay sensitivity and specificity. We estimated that 5.9% of the population had vaccine-induced seropositivity while 25% had seropositivity secondary to pH1N1 virus infection. The highest cumulative incidence of pH1N1 virus infection was among children aged 5-17 years (53%) and young adults aged 18-24 years (47%), while adults aged ≥50 years had the lowest cumulative incidence (11-13%) of pH1N1 virus infection. CONCLUSIONS: After the peak of the fall wave of the pandemic, an estimated one quarter of the Tampa Bay population had been infected with the pH1N1 virus. Consistent with epidemiologic trends observed during the pandemic, the highest burdens of disease were among school-aged children and young adults.