Please cite this paper as: Comas‐García et al. (2011) Mortality attributable to pandemic influenza A (H1N1) 2009 in San Luis Potosí, Mexico. Influenza and Other Respiratory Viruses 5(2), 76–82. Background  Acute respiratory infections are a leading cause of morbidity and mortality worldwide. Starting in 2009, pandemic influenza A(H1N1) 2009 virus has become one of the leading respiratory pathogens worldwide. However, the overall impact of this virus as a cause of mortality has not been clearly defined. Objectives  To determine the impact of pandemic influenza A(H1N1) 2009 on mortality in a Mexican population. Methods  We assessed the impact of pandemic influenza virus on mortality during the first and second outbreaks in San Luis Potosí, Mexico, and compared it to mortality associated with seasonal influenza and respiratory syncytial virus (RSV) during the previous winter seasons. Results  We estimated that, on average, 8·1% of all deaths that occurred during the 2003–2009 seasons were attributable to influenza and RSV. During the first pandemic influenza A(H1N1) 2009 outbreak, there was an increase in mortality in persons 5–59 years of age, but not during the second outbreak (Fall of 2009). Overall, pandemic influenza A (H1N1) 2009 outbreaks had similar effects on mortality to those associated with seasonal influenza virus epidemics. Conclusions  The impact of influenza A(H1N1) 2009 virus on mortality during the first year of the pandemic was similar to that observed for seasonal influenza. The establishment of real‐time surveillance systems capable of integrating virological, morbidity, and mortality data may result in the timely identification of outbreaks so as to allow for the institution of appropriate control measures to reduce the impact of emerging pathogens on the population.

Cattle babesiosis is a socio-economically important tick-borne disease caused by Apicomplexa protozoa of the genus Babesia that are obligate intraerythrocytic parasites. The pathogenicity of Babesia parasites for cattle is determined by the interaction with the host immune system and the presence of the parasite’s virulence genes. A Babesia bigemina strain that has been maintained under a microaerophilic stationary phase in in vitro culture conditions for several years in the laboratory lost virulence for the bovine host and the capacity for being transmitted by the tick vector. In this study, we compared the virulome of the in vitro culture attenuated Babesia bigemina strain (S) and the virulent tick transmitted parental Mexican B. bigemina strain (M). Preliminary results obtained by using the Basic Local Alignment Search Tool (BLAST) showed that out of 27 virulence genes described and analyzed in the B. bigemina virulent tick transmitted strain, only five were fully identified in the attenuated laboratory strain. In all cases, the identity and coverture of the identified genes of the wildtype strain were higher than those of the laboratory strain. This finding is putatively associated with the continuous partial loss of virulence genes in the laboratory strain after several passages of the parasite population under optimal in vitro growth conditions. The loss of virulence factors might be reflected in the absence of symptoms of the disease in cattle inoculated with the attenuated strain despite the presence of infection in the bovine host cells.

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Data on the implication of the stable fly (Stomoxys calcitrans, Diptera: Muscidae), in the transmission of Anaplasma marginale in tick-free cattle is scarce. Hence, the objective of this investigation was to detect the presence of DNA from A. marginale in stable flies caught near a bovine herd, which has been maintained free of ticks for 40 years, and occasionally presents some clinical cases of anaplasmosis. Twenty-four batches of S. calcitrans (15 flies each) were collected in the morning and in the afternoon twice a week (except for one catch in one week of September and one catch in one week of December) during 12 catching days in a period of four months. Their DNA was obtained and analysed by nested PCR (nPCR) to identify the presence of A. marginale DNA. Seven of the batches (29.16 %) were positive for A. marginale, as detected by an nPCR that targets the A. marginale msp5 gene. Similarly, in two out of 12 catching days (16.66 %), those S. calcitrans batches collected in the morning and in the afternoon, were positive for A. marginale, while those S. calcitrans groups collected in three out of 12 catching days (25 %), were positive for the rickettsia. The obtained results suggest that A. marginale transmission is carried out mechanically by S. calcitrans, favouring the circulation and maintenance of the microorganism in this particular bovine herd.

Babesia bovis , a tick-borne intraerythrocytic protozoan parasite that belongs to the phylum Apicomplexa, is one of the etiological agents of bovine babesiosis, a highly prevalent disease in tropical and subtropical countries that causes significant morbidity and deaths in cattle. This report presents the draft genome sequences of attenuated and virulent B. bovis strains of Mexican origin.