Captures d'écran : la photographie de presse et l'image télévisée

Influenza-associated disease burden among children in tropical sub-Saharan Africa is not well established, particularly outside of the 2009 pandemic period. We estimated the burden of influenza in children aged 0-4 years through population-based surveillance for influenza-like illness (ILI) and acute lower respiratory tract illness (ALRI). Household members meeting ILI or ALRI case definitions were referred to health facilities for evaluation and collection of nasopharyngeal and oropharyngeal swabs for influenza testing by real-time reverse transcription polymerase chain reaction. Estimates were adjusted for health-seeking behavior and those with ILI and ALRI who were not tested. During 2008-2012, there were 9,652 person-years of surveillance among children aged 0-4 years. The average adjusted rate of influenza-associated hospitalization was 4.3 (95% CI 3.0-6.0) per 1,000 person-years in children aged 0-4 years. Hospitalization rates were highest in the 0-5 month and 6-23 month age groups, at 7.6 (95% CI 3.2-18.2) and 8.4 (95% CI 5.4-13.0) per 1,000 person-years, respectively. The average adjusted rate of influenza-associated medically attended (inpatient or outpatient) ALRI in children aged 0-4 years was 17.4 (95% CI 14.2-19.7) per 1,000 person-years. Few children who had severe laboratory-confirmed influenza were clinically diagnosed with influenza by the treating clinician in the inpatient (0/33, 0%) or outpatient (1/109, 0.9%) settings. Influenza-associated hospitalization rates from 2008-2012 were 5-10 times higher than contemporaneous U.S. estimates. Many children with danger signs were not hospitalized; thus, influenza-associated severe disease rates in Kenyan children are likely higher than hospital-based estimates suggest

Examining strain diversity and phylogeography in relation to an unusual epidemic pattern of respiratory syncytial virus (RSV) in a long-term refugee camp in Kenya

Background: A recent longitudinal study in the Dadaab refugee camp near the Kenya-Somalia border identified unusual biannual respiratory syncytial virus (RSV) epidemics. We characterized the genetic variability of the associated RSV strains to determine if viral diversity contributed to this unusual epidemic pattern. Methods: For 336 RSV positive specimens identified from 2007 through 2011 through facility-based surveillance of respiratory illnesses in the camp, 324 (96.4%) were sub-typed by PCR methods, into 201 (62.0%) group A, 118 (36.4%) group B and 5 (1.5%) group A-B co-infections. Partial sequencing of the G gene (coding for the attachment protein) was completed for 290 (89.5%) specimens. These specimens were phylogenetically analyzed together with 1154 contemporaneous strains from 22 countries. Results: Of the 6 epidemic peaks recorded in the camp over the period, the first and last were predominantly made up of group B strains, while the 4 in between were largely composed of group A strains in a consecutive series of minor followed by major epidemics. The Dadaab group A strains belonged to either genotype GA2 (180, 98.9%) or GA5 (2, < 1%) while all group B strains (108, 100%) belonged to BA genotype. In sequential epidemics, strains within these genotypes appeared to be of two types: those continuing from the preceding epidemics and those newly introduced. Genotype diversity was similar in minor and major epidemics. Conclusion: RSV strain diversity in Dadaab was similar to contemporaneous diversity worldwide, suggested both between-epidemic persistence and new introductions, and was unrelated to the unusual epidemic pattern

Human brucellosis in Baringo County, Kenya: Evaluating the diagnostic kits used and identifying infecting Brucella species.

Human brucellosis diagnosis has been a challenge in Brucella-endemic areas. In Kenya, diagnosis is usually carried out using Febrile Brucella Antigen agglutination test (FBAT) whose performance is not well documented. This paper reports on the sensitivity and specificity of the FBAT used for brucellosis diagnosis on blood samples/serum collected in three healthcare facilities in Baringo County, Kenya, and on Brucella species present in the study area. The FBAT test results at the hospitals were used to guide patient management. Patients who visited the hospital's laboratory with a clinician's request for brucellosis testing also filled a questionnaire to assess knowledge and attitudes associated with transmission of the disease in the study area. The remaining serum samples were tested again using FBAT and Rose Bengal Plate Test (RBPT) within a month of blood collection at the University Nairobi Laboratory. The two rapid tests were then compared, with respect to brucellosis diagnostic sensitivity and specificity. To identify infecting Brucella species, a proportion 43% (71/166) of the blood clots were analyzed by multiplex polymerase chain reaction (PCR) using specific primers for B. abortus, B. melitensis, B. ovis and B. suis. Out of 166 serum samples tested, 26.5% (44/166) were positive using FBAT and 10.2% (17/166) positive using RBPT. The sensitivity and specificity of FBAT compared to RBPT was 76.47% and 71.19%, respectively while the positive and negative predictive values were 29.55% and 96.72%, respectively. The FBAT showed higher positivity then RBPT. The difference in sensitivity and specificity of FBAT and RBPTs was relatively low. The high FBAT positivity rate would be indication of misdiagnosis; this would lead to incorrect treatment. Brucella abortus was detected from 9.9% (7/71) of the blood clots tested; no other Brucella species were detected. Thus human brucellosis, in Baringo was mainly caused by B. abortus

SOCS-1 Mimetics Protect Mice against Lethal Poxvirus Infection: Identification of a Novel Endogenous Antiviral System ▿

The suppressor of cytokine signaling 1 (SOCS-1) protein modulates cytokine signaling by binding to and inhibiting the function of Janus kinases (JAKs), ErbB, and other tyrosine kinases. We have developed a small tyrosine kinase inhibitor peptide (Tkip) that binds to the autophosphorylation site of tyrosine kinases and inhibits activation of STAT transcription factors. We have also shown that a peptide corresponding to the kinase-inhibitory region of SOCS-1, SOCS1-KIR, similarly interacts with the activation loop of JAK2 and blocks STAT activation. Poxviruses activate cellular tyrosine kinases, such as ErbB-1 and JAK2, in the infection of cells. We used the pathogenesis of vaccinia virus in C57BL/6 mice to determine the ability of the SOCS-1 mimetics to protect mice against lethal vaccinia virus infection. Injection of mice intraperitoneally with Tkip or SOCS1-KIR containing a palmitate for cell penetration, before and at the time of intranasal challenge with 2 × 106 PFU of vaccinia virus, resulted in complete protection at 100 μg. Initiation of treatment 1 day postinfection resulted in 80% survival. Administration of SOCS-1 mimetics by the oral route also protected mice against lethal effects of the virus. Both SOCS1-KIR and Tkip inhibited vaccinia virus transcription and replication at early and possibly later stages of infection. Vaccinia virus-induced phosphorylation of ErbB-1 and JAK2 was inhibited by the mimetics. Protected mice mounted a strong humoral and cellular response to vaccinia virus. The use of SOCS-1 mimetics in the treatment of poxvirus infections reveals an endogenous regulatory system that previously was not known to have an antiviral function

Agarose gel electrophoresis showing 100bp molecular marker (M), negative samples 1, 2, 3, 4, positive samples 5, positive control 6 (S19 <i>B</i>. <i>abortus</i>) and negative control 7 (double distilled water).

Agarose gel electrophoresis showing 100bp molecular marker (M), negative samples 1, 2, 3, 4, positive samples 5, positive control 6 (S19 B. abortus) and negative control 7 (double distilled water).</p

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Sensitivity, specificity and predictive values of FBAT compared to RBPT.

Sensitivity, specificity and predictive values of FBAT compared to RBPT.</p

Results of three serological tests used on the serum samples collected from Baringo Hospitals.

Results of three serological tests used on the serum samples collected from Baringo Hospitals.</p