Polymorphic variability in immune response genes, such as IL12B, encoding the IL-12p40 subunit is associated with susceptibility to severe malaria in African populations. Since the role of genetic variation in conditioning severe malaria in Thai adults is largely unexplored, the functional association between IL12B polymorphisms [i.e., IL12Bpro (rs17860508), and IL12B 3' UTR T/G (rs3212227)], severe malaria, and cytokine production was examined in patients with Plasmodium falciparum infections (n=355) recruited from malaria endemic areas along the Thai-Myanmar border in northwest Thailand. Circulating IL-12p40 (p=0.049) and IFN-γ (p=0.051) were elevated in patients with severe malaria, while only IL-12p40 was significantly higher in severe malaria patients with hyperparasitaemia (p=0.046). Carriage of the IL12Bpro1.1 genotype was associated with enhanced severity of malaria (OR, 2.34; 95% CI, p=0.066) and hyperparasitaemia (OR, 3.42; 95% CI, 1.17-9.87; p=0.025) relative to the IL12Bpro2.2 genotype (wild type). Individuals with the IL12Bpro1.1 genotype also had the lowest IL-12p40 (p=0.002) and the highest IFN-γ (p=0.004) levels. Construction of haplotypes revealed that carriage of the IL12Bpro-2/3' UTR-T haplotype was associated with protection against severe malaria (OR, 0.51; 95% CI, 0.29-0.90; p=0.020) and reduced circulating IFN-γ (p=0.06). Thus, genotypic and

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Oseltamivir is often prescribed to treat influenza patients, yet its effect on viral shedding among Thai young adults infected with influenza A(H1N1)pdm09 virus remained unclear. During May to June 2011, an influenza A(H1N1)pdm09 outbreak was detected in University S, Nakhon Ratchasima Province, Thailand. A prospective observational study was conducted to define duration of viral shedding and immunologic response in infected students undergoing oseltamivir treatment, and identify factors associated with viral shedding. We enrolled all acute respiratory illness (ARI) patients attending the medical center at University S during 3-7 Jun 2011 with laboratory confirmation of influenza A(H1N1)pdm09 infection by real-time reverse transcription polymerase chain reaction (rRT-PCR). Additional throat swabs were collected and tested daily until rRT-PCR results became negative through two consecutive days. Series of serum samples for hemagglutination inhibition (HI) test were also collected from the individuals. Log-rank test was applied in analysis of association between patients’ characteristics and duration of viral shedding. Of 29 sick students enrolled, 45% were males. All were prescribed oseltamivir for five days and none of them were hospitalized. Median duration from onset of symptoms to the last day of viral shedding detected was five days (range 3-9 days). Over 80% of the patients had 4-fold rises of HI titer within 2-3 weeks after onset of symptoms. None of the patients’ characteristics were significantly associated with duration of viral shedding. However, persons with delayed antiviral treatment tended to have longer duration of viral shedding. Early oseltamivir treatment probably reduced risks of severe influenza in young adult patients. However, guidelines on infection control need to emphasize on strict hygiene and prevention measures in treated patients for nine days in order to minimize the risks of influenza transmission.