Crimean-Congo Hemorrhagic Fever in Central Uganda, 2017

Crimean-Congo hemorrhagic fever (CCHF) is the most widespread tick-borne viral hemorrhagic fever in the world and a threat to global health security; a single case counts as an outbreak. People catch it from tick bites or from contact with the blood or body fluids of infected people or animals. There is no licensed vaccine, treatment is supportive, and between 3% and 40% of patients die. Uganda reported cases between 1958 and 1977, then none until 2013, when stronger surveillance for viral hemorrhagic fevers began to detect outbreaks.

The outbreak

On August 20, 2017, doctors in two non-neighboring districts of central Uganda, Kyankwanzi and Nakaseke, reported two unrelated CCHF cases. Both were confirmed by antibody and RT-PCR testing at the Uganda Virus Research Institute, through a specimen referral system set up in 2013 with CDC help to strengthen global health security. The Ministry of Health sent a team to investigate on August 22.

Investigators reviewed hospital records of patients with fever and bleeding and searched the communities for more cases. Besides the two confirmed patients, both of whom survived, five of 23 patients whose records were reviewed met the suspected-case definition — sudden fever above 100.4°F (38°C) for three days or more, plus bleeding or bruising or unexplained low white-cell or platelet counts — and two of them died. No specimens were available to confirm their infections. Illness began between July 9 and September 17. All patients were men aged 19 to 87, and there were no secondary cases.

What exposed them

A case-control study compared the patients with four age- and sex-matched neighbors each. Four of the seven patients reported tick exposure, against 3 of 28 (11%) controls — about 11 times the odds. Because infected animals can carry high levels of virus without looking sick, cattle and goats were tested on the two farms where the confirmed patients worked: 37 of 62 cattle (60%) and 5 of 21 goats (24%) had antibodies to CCHF. The animals were quarantined for a month, and owners and workers were told to wear protection when handling them.

The response

• Rapid response teams in both districts were activated on August 23, with an emergency hotline for reporting cases.
• Hospitals set up isolation units to screen and isolate suspected cases and collect blood for testing.
• Health workers were trained in patient care and infection control.
• District veterinary officers advised farmers, especially those with antibody-positive animals, on tick control such as dipping livestock in acaricide.
• From August 24 to September 30, radio programs taught residents the signs of CCHF and how to protect themselves: never handle ticks bare-handed, and wear gloves, boots and protective clothing when herding livestock.

No further cases were reported. The fast, coordinated response, the authors wrote, showed the progress Uganda had made in strengthening global health security.

Sources

• Kizito S, Okello PE, Kwesiga B, et al. "Notes from the Field: Crimean-Congo Hemorrhagic Fever Outbreak — Central Uganda, August–September 2017." MMWR 2018;67(22).