Ethnic disparities in acquiring 2009 pandemic H1N1 influenza: a case–control study

Introduction. Influenza A H1N1 community-acquired pneumonia (CAP) is a quite frequent respiratory disease. Despite being considered more serious than other CAPs, there are very few studies comparing its characteristics with noninfluenza CAP. We aim to establish the differences between pneumonia due to H1N1 virus and pneumonia not caused by H1N1 influenza virus and to determine the probability that a pneumonia is due to an H1N1 virus infection based on the most relevant variables. Methods. We used a case-control study where cases were H1N1 CAP patients with confirmed microbiological diagnosis and controls were patients with CAP admitted to hospital. H1N1 and other influenza types were discarded among controls. We calculated the probability of being a case or control using multivariate logistic regression. Results. We included 99 cases and 270 controls. Cases were younger than controls (53 vs 71 years, respectively). Mortality was much higher for H1N1 patients (13% vs 0.3%), and admission to intensive care unit was more frequent for H1N1 cases. The variables most associated with presenting H1N1 CAP were bilateral affectation on chest X-rays (OR: 5.70; 95% CI 2.69–10.40), followed by presence of arthromyalgias, with cases presenting close to three times more arthromyalgias compared to controls. Low leukocytes count and high AST values were also significantly associated with H1N1 CAP. H1N1 CAPs are characterized by bilateral affectation, low leukocyte count, presence of arthromyalgias, and high AST. Conclusions. A few and easy to obtain clinical parameters might be extremely useful to distinguish H1N1 CAP from CAPs of other origin.

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Asthma and severity of the 2009 novel H1N1 influenza: a case-control study

Journal of Asthma ◽

10.3109/02770903.2013.838257 ◽

2013 ◽

Vol 51 (1) ◽

pp. 69-74 ◽

Cited By ~ 2

Author(s):

Yong Bum Park ◽

Changhwan Kim ◽

Yong Il Hwang ◽

Chang Lyul Lee ◽

Won-Yeon Lee ◽

...

Keyword(s):

Influenza A ◽

Case Control Study ◽

H1n1 Influenza ◽

Case Control ◽

Novel H1n1 Influenza ◽

Control Study

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Influenza A (H1N1) virus infection and TNF-308, IL6, and IL8 polymorphisms in Egyptian population: a case–control study

The Journal of Basic and Applied Zoology ◽

10.1186/s41936-019-0131-1 ◽

2019 ◽

Vol 80 (1) ◽

Cited By ~ 1

Author(s):

Shaimaa Moustafa Elsayed ◽

Omayma Mohamed Hassanein ◽

Nagwa Hassan Ali Hassan

Keyword(s):

Influenza A ◽

Case Control Study ◽

H1n1 Virus ◽

Case Control ◽

Severe Illness ◽

Study Results ◽

Influenza A H1n1 ◽

Pandemic Strains ◽

Study Participants ◽

Control Study

Abstract Background The importance of influenza is increasing mainly because of the appearance of novel pandemic strains such as swine and avian. Each year, influenza has spread around the world causing about 250,000–500,000 deaths and more than 5 million cases of severe illness. The objective is as follows: evaluating the outcomes of patients with influenza A (H1N1) virus in relation to certain TNF-308, IL6, and IL8 polymorphisms and identifying the associated factors with the severe outcome. Subject and methods This is a case–control study. The cases were patients confirmed by real-time polymerase chain reaction (RT-PCR) to be influenza A (H1N1) virus infected. The controls were healthy individuals. Medical history and outcome of the disease was registered. In all study participants, polymorphisms of TNF rs1800629, IL6 rs18138879, and IL8 rs4073; odds ratio (OR); and the 95% confidence interval (95% CI) were calculated. Results Infection with influenza A (H1N1) virus was associated more with the following genotypes: TNF-308 AA (OR = 4.041; 95% CI = 1.215–13.4) and IL8 AA (OR = 3.273; 95% CI = 1.372–7.805). According to our study results, HCV (OR = 3.2, 95% CI 1.2–8.5), renal disease (OR = 3.4, 95% CI 0.9–13.6), cancer (OR = 3.1, 95% CI 0.3–31.1), TB (OR = 8.4, 95% CI 1.8–39.7), ICU (OR = 2.9, 95%1.2–7.1), and mortality (OR = 7.9, 95% CI 0.9–67.4) are considered as risk factors for influenza A (H1N1)-infected patients. Conclusions Our findings concluded that TNF-308 (AA) and IL8 (AA) polymorphisms may increase the susceptibility to be infected with H1N1influenza virus.

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