On April 23, 2016, the Democratic Republic of the Congo's (DRC's) Ministry of Health declared a yellow fever outbreak. As of May 24, 2016, approximately 90% of suspected yellow fever cases (n = 459) and deaths (45) were reported in a single province, Kongo Central Province, that borders Angola, where a large yellow fever outbreak had begun in December 2015. Two yellow fever mass vaccination campaigns were conducted in Kongo Central Province during May 25-June 7, 2016 and August 17-28, 2016. In June 2016, the DRC Ministry of Health requested assistance from CDC to control the outbreak. As of August 18, 2016, a total of 410 suspected yellow fever cases and 42 deaths were reported in Kongo Central Province. Thirty seven of the 393 specimens tested in the laboratory were confirmed as positive for yellow fever virus (local outbreak threshold is one laboratory-confirmed case of yellow fever). Although not well-documented for this outbreak, malaria, viral hepatitis, and typhoid fever are common differential diagnoses among suspected yellow fever cases in this region. Other possible diagnoses include Zika, West Nile, or dengue viruses; however, no laboratory-confirmed cases of these viruses were reported. Thirty five of the 37 cases of yellow fever were imported from Angola. Two-thirds of confirmed cases occurred in persons who crossed the DRC-Angola border at one market city on the DRC side, where ≤40,000 travelers cross the border each week on market day. Strategies to improve coordination between health surveillance and cross-border trade activities at land borders and to enhance laboratory and case-based surveillance and health border screening capacity are needed to prevent and control future yellow fever outbreaks.

On April 23, 2016, the Democratic Republic of the Congo (DRC) Ministry of Health reported an outbreak of yellow fever. As of May 24, 2016, among 41 confirmed yellow fever cases, 31 (75.6%) had occurred in Kongo Central Province, in the western part of the country bordering Angola (1), where a large yellow outbreak had begun in December 2015. In response, during May 25–June 7, 2016, the DRC Ministry of Health administered approximately 240,000 doses of yellow fever vaccine to all persons aged ≥9 months during a mass vaccination campaign in Matadi, one of 31 health zones in the Kongo Central Province. The administrative vaccination coverage (i.e., the number of vaccine doses administered divided by the most recent census estimates for the target population), was estimated to have reached >99%. | During the campaign, health workers in the Matadi Health Zone were trained to identify adverse events following immunization (AEFIs), complete case report forms, and send forms weekly to both provincial officials and a national expert committee for vaccine pharmacovigilance. Although a provisional classification of AEFIs by severity is made at peripheral and provincial levels at the time of an initial investigation, responsibilities at the national level are to guide the investigation of suspected serious AEFIs, classify them according to standard AEFI cause–specific definitions, recommend additional testing of biologic specimens if warranted, and determine causality.

OBJECTIVE: To assess L-tryptophan (LT) dose, age, sex, and immunogenetic markers as possible risk or protective factors for the development of LT-associated eosinophilia-myalgia syndrome (EMS) and related clinical findings. METHODS: HLA-DRB1 and DQA1 allele typing and Gm/Km phenotyping were performed on a cohort of 94 white subjects with documented LT ingestion and standardized evaluations. Multivariate analyses compared LT dose, age, sex, and alleles among groups of subjects who ingested LT and subsequently developed surveillance criteria for EMS, developed EMS or characteristic features of EMS (EMS spectrum disorder), or developed no features of EMS (unaffected). RESULTS: Considering all sources of LT, higher LT dose (odds ratio [OR] 1.4, 95% confidence interval [95% CI] 1.1-1.8), age >45 years (OR 3.0, 95% CI 1.0-8.8), and HLA-DRB1*03 (OR 3.9, 95% CI 1.2-15.2), DRB1*04 (OR 3.9, 95% CI 1.1-16.4), and DQA1*0601 (OR 13.7, 95% CI 1.3-1.8) were risk factors for the development of EMS, whereas DRB1*07 (OR 0.12, 95% CI 0.02-0.48) and DQA1*0501 (OR 0.23, 95% CI 0.05-0.85) were protective. Similar risk and protective factors were seen for developing EMS following ingestion of implicated LT, except that DRB1*03 was not a risk factor and DQA1*0201 was an additional protective factor. EMS spectrum disorder also showed similar findings, but with DRB1*04 being a risk factor and DRB1*07 and DQA1*0201 being protective. There were no differences in sex distribution, Gm/Km allotypes, or Gm/Km phenotypes among any groups. CONCLUSION: In addition to the xenobiotic dose and subject age, polymorphisms in immune response genes may underlie the development of certain xenobiotic-induced immune-mediated disorders, and these findings may have implications for future related epidemics.