Impact of seasons on tuberculosis mortality for HIV+ and HIV- TB patients

<b>Background:</b> Assessing the difference in the seasonality of death from TB can provide an answer to the question of whether the nature of the incidence of TB death cases in the presence or absence of HIV infection is different. <b>Aims:</b> Assessment of the presence of seasonal differences in mortality depending on the presence of HIV infection <b>Methods:</b> TB associated monthly deaths of TB/HIV+ (926) and TB/HIV- (1050) patients in 2013-2018 were analyzed. The monthly data for 6 years were summed up for every month, and then compared with a theoretical uniform distribution of TB death frequency (TBDF). <b>Results:</b> For the TB/HIV- death cases (cause of death was TB), a year can be divided on two periods: January-April - increase of monthly TBDF by 16.3% (407 deaths or 38.7%, 95%CI 35.8-41.8% from annually people died, more than the theoretical TBDF equaling one third or 33.3%, p = 0.0098) May-December - decrease by 8,14%. The seasonal indices had high values in the first period of the year 104.0-126.8% with maximum value in January. The seasonal indices in the second period had low values - 77.7-101.7 % with a minimum value in November. For TB/HIV+ patients, died of HIV-infection associated with TB (B20.0/B20.7 according ICD-10), the distribution of TBDF was more evenly. Only May TBDF data showed 10.48% which was significantly differed from uniform distribution (p &lt;0.05). Fluctuations in the values of the seasonal indices from 81.6% in November to 125.7% in May were observed. <b>Conclusions:</b> In conditions of comparable low TB incidence, impact of season factors on TB death incidence is different for HIV+ and HIV- TB patients.