Establishment and cryptic transmission of Zika virus in Brazil and the Americas.

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.

Association between sensory dysfunction and pain 1 week after breast cancer surgery: a psychophysical study.

BACKGROUND: Breast cancer patients treated with axillary lymph node dissection (ALND) have a higher risk of both acute and persistent pain than those treated with sentinel lymph node biopsy (SLNB). This could be attributed to a higher risk of nerve injury with ALND. We hypothesized that (1) pain patients have more pronounced sensory dysfunction than pain-free patients, (2) ALND have more sensory dysfunction and pain than SLNB patients and (3) patients with preserved intercostobrachial nerve (ICBN) preservation have less sensory dysfunction compared to a sectioned ICBN. METHODS: Twenty-seven patients treated with ALND and 27 with SLNB examined with a standardized Quantitative Sensory Testing (QST) protocol, including sensory mapping, mechanical and thermal thresholds, as well as recording intraoperative ICBN handling and pain status 1 week post-operative. RESULTS: The area of cold hypoaesthesia was significantly associated with movement-related pain (P = 0.004), with a similar tendency for warmth (P = 0.018) and brush (P = 0.030) hypoaesthesia areas. 14 (26%) of the patients had moderate/severe pain at rest and 13 (24%) during movement without differences between ALND and SLNB, but ALND was associated with more sensory dysfunction than SLNB. Patients with sectioned ICBN reported lower pain intensity than those with preserved ICBN (P = 0.005), but without differences in sensory dysfunction. CONCLUSION: Pain was increased in patients having larger areas of hypoaesthesia and reduced in patients where ICBN-section was done. Sensory dysfunction was related to extent of axillary surgery, but not with ICBN handling. Our data suggest that acute pain after breast cancer surgery may be related to nerve injury.

Intercostobrachial nerve handling and pain after axillary lymph node dissection for breast cancer.

BACKGROUND: Moderate to severe pain in the first week after axillary lymph node dissection (ALND) for breast cancer is experienced by approximately 50% of the patients. Damage to the intercostobrachial nerve (ICBN) has been proposed as a risk factor for the development of persistent pain following breast cancer surgery but with limited information on acute post-operative pain. The aim of the present study was to examine the influence of ICBN handling on pain during the first week after ALND. METHODS: The study was part of a larger prospective cohort study on persistent pain after breast cancer treatment. Pain and sensory disturbances were assessed pre-operatively, within the first 72 h post-operatively and a week after surgery. Intraoperative handling of the nerve was recorded by the surgeon as preserved, partially preserved or sectioned. RESULTS: One hundred forty-one patients were treated with ALND level I + II, and the ICBN could be identified in 125 (89%) patients. Of the 17 not identified, eight were stated as without any sign of the nerve and were included in analysis as sectioned. Thus, the analysis included 133 patients in which 45 (34%) of these the ICBN was preserved, 39 (29%) partially preserved and 49 (37%) sectioned. At 1 week after surgery, 104 patients (78%) reported pain, whereas 35 (26%) reported moderate to severe pain. There was no difference between the ICBN groups in pain scores or sensory disturbances measured pre-operatively compared to 1 week post-operatively. CONCLUSION: The type of ICBN handling during ALND may not influence acute post-operative pain in the first week after surgery.

Persistent pain, sensory disturbances and functional impairment after immediate or delayed axillary lymph node dissection.

BACKGROUND: Patients treated with 2-step axillary lymph node dissection (ALND) may be at increased risk of nerve damage due to more challenging surgery than an ALND immediately after a sentinel lymph node biopsy (SLNB), and thus more at risk for persistent pain after breast cancer treatment (PPBCT). The aim of this study was to examine PPBCT, sensory disturbances and functional impairment in patients treated with a 2-step ALND compared to patients with an SLNB followed by an immediate ALND, and patients with ALND without a prior SLNB. METHODS: The study is a cross-sectional questionnaire study, comparing 2847 women treated with ALND in Denmark in 2005-2008. 196 patients treated with a 2-step ALND were compared with 1558 patients treated with an ALND after SLNB and 1093 with an ALND without a prior SLNB. RESULTS: Overall prevalence of PPBCT and sensory disturbances was high, with about 55% reporting PPBCT and 77% reporting sensory disturbances in all groups. No differences were found between the groups on prevalence and intensity of PPBCT (p = 0.92), sensory disturbances (p = 0.32), and functional consequences (p = 0.35). CONCLUSIONS: A 2-step ALND does not modify the risk of developing PPBCT compared to an immediate ALND.