Avian influenza surveillance in Central and West Africa, 2010-2014.

Avian influenza virus (AIV) is an important zoonotic pathogen, resulting in global human morbidity and mortality and substantial economic losses to the poultry industry. Poultry and wild birds have transmitted AIV to humans, most frequently subtypes H5 and H7, but also different strains and subtypes of H6, H9, and H10. Determining which birds are AIV reservoirs can help identify human populations that have a high risk of infection with these viruses due to occupational or recreational exposure to the reservoir species. To assess the prevalence of AIV in tropical birds, from 2010 to 2014, we sampled 40 099 birds at 32 sites in Central Africa (Cameroon, Central African Republic, Congo-Brazzaville, Gabon) and West Africa (Benin, Côte d'Ivoire, Togo). In Central Africa, detection rates by real-time RT-PCR were 16·6% in songbirds (eight passerine families, n = 1257), 16·4% in kingfishers (family Alcedinidae, n = 73), 8·2% in ducks (family Anatidae, n = 564), and 3·65% in chickens (family Phasianidae, n = 1042). Public health authorities should educate human cohorts that have high exposure to these bird populations about AIV and assess their adherence to biosecurity practices, including Cameroonian farmers who raise small backyard flocks.

Enhancement of cisplatin cytotoxicity by terbium in cisplatin-resistant MDA/CH human breast cancer cells.

PURPOSE: The development of cisplatin resistance is a major problem in the treatment of cancer patients with cisplatin chemotherapy. The membrane binding of terbium (Tb3+) has been shown to increase the cellular accumulation of cisplatin in breast cancer cells. Therefore, the ability of Tb3- to modulate the cytotoxicity of cisplatin was investigated in cisplatin-sensitive (MDA) and cisplatin-resistant (MDA/CH) MDA-MB-231 human breast cancer cells. METHODS: The cytotoxic parameters of cisplatin were determined using live cell microfluorometry and median effect analysis. RESULTS: MDA/CH cells (IC50 = 142 +/- 9 microM) were found to be approximately 3.3-fold more resistant to cisplatin than MDA cells (IC50 = 43.5 +/- 3.0 microM). In both cell lines, the IC50 value for cisplatin was reduced two-fold in the presence of 80 microM Tb3+, thus indicating that the cytotoxicity of cisplatin is increased by Tb3+. The cytotoxic activity of cisplatin alone was observed to be 5.7 and 1.6 times more potent than that of Tb3+ alone in MDA and MDA/CH cells, respectively. Combination index analyses revealed that the interaction between cisplatin and Tb3+ was only synergistic at very low indices of cell death in MDA cells. However, in MDA/CH cells, the two drugs were synergistic up to intermediate levels of cell death. CONCLUSIONS: Our results suggest that the enhancement of cisplatin cytotoxicity by Tb3- is more effective in cisplatin-resistant MDA/CH cells than in cisplatin-sensitive MDA cells. Therefore, terbium is potentially useful in cisplatin combination therapy for breast cancer patients, especially for those patients who have developed resistance to the drug.