In 2017, a monkeypox outbreak occurred in Likouala Department, Republic of the Congo. Many of the affected individuals were of Aka ethnicity, hunter-gatherers indigenous to Central Africa who have worse health outcomes in comparison with other forest-dwelling peoples. To test the hypothesis that Aka people have different risk factors for monkeypox, we analyzed questionnaire data for 39 suspected cases, comparing Aka and Bantu groups. Aka people were more likely to touch animal urine/feces, find dead animals in/around the home, eat an animal that was found dead, or to have been scratched or bitten by an animal (P < 0.05, all variables). They were also more likely to visit the forest >/= once/week, sleep outside, or sleep on the ground (P < 0.001, all variables), providing opportunities for contact with monkeypox reservoirs during the night. The Aka and possibly other vulnerable groups may warrant special attention during educational and health promotion programs.

Monkeypox, caused by a zoonotic orthopoxvirus, is endemic in Central and West Africa. Monkeypox has been sporadically reported in the Republic of the Congo. During March 22-April 5, 2017, we investigated 43 suspected human monkeypox cases. We interviewed suspected case-patients and collected dried blood strips and vesicular and crust specimens (active lesions), which we tested for orthopoxvirus antibodies by ELISA and monkeypox virus and varicella zoster virus DNA by PCR. An ecologic investigation was conducted around Manfouete, and specimens from 105 small mammals were tested for anti-orthopoxvirus antibodies or DNA. Among the suspected human cases, 22 met the confirmed, probable, and possible case definitions. Only 18 patients had available dried blood strips; 100% were IgG positive, and 88.9% (16/18) were IgM positive. Among animals, only specimens from Cricetomys giant pouched rats showed presence of orthopoxvirus antibodies, adding evidence to this species' involvement in the transmission and maintenance of monkeypox virus in nature.

Reports of 10 suspected cases of monkeypox in Likouala Department, Republic of the Congo, triggered an investigation and response in March 2017 that included community education and surveillance strengthening. Increasing numbers of outbreaks suggest that monkeypox virus is becoming a more prevalent human pathogen. Diverse approaches are necessary for disease control and prevention.

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.