One Health Students Participate in Suspected Human Anthrax Outbreak Investigation and Surveillance

Friday, 25 August 2017 - 9:26am
OHCEA Network Country: 
The audience follows keenly and interrogates the presentation done by students who participated in the investigation

Anthrax is a zoonotic disease transmitted to humans mainly from herbivores and domestic animals, caused by a Gram-positive, spore forming bacillus known as Bacillus anthracis. Humans are infected by contact with infected animal tissue through  cutaneous, respiratory or gastrointestinal routes. Human to human transmission is very rare but can occur through contact with open wounds.

Anthrax is an endemic, notifiable disease in Kenya and is also ranked as the most important zoonotic disease in the country. Spontaneous anthrax outbreaks occur at the humans-livestock interface annually but it is not possible to estimate the true disease incidence because of underreporting and limited diagnostic capacity in both the human and animal health sector at sub-national level. Since 2005, anthrax outbreaks have occurred in Samburu (years 2005 and 2006), central province (years 2009 and 2010), Kiambu ( year 2010), Kakamega ( years 2014), Embu ( year 2014), Narok (year 2014), Nakuru (year 2014 and 2016) and Murang’a ( year 2016) with a cumulative 213 cases and 12 deaths.

The Disease Surveillance and Response Unit (DSRU) and the Zoonotic Disease Unit (ZDU) were notified of reported cases of suspected human anthrax cases admitted at Thika County Referral hospital on 10th May 2017. A multidisciplinary team comprising of officers from ZDU, Field Epidemiology programme (FELTP) and the OHCEA/ Kenya including veterinary students from the University of Nairobi were deployed to investigate the outbreak.

The goals and objectives of the activity were;

  1. To describe and document the outbreak in terms of:
    • Clinical aspects of the cases of suspected cutaneous anthrax admitted at Thika County referral hospital,
    • Control efforts undertaken by both the County health and veterinary departments and
    • The circumstances surrounding the outbreak.
  2. To train students in the prevention, detection, and control of infectious diseases outbreak

The investigation was designed to reach victims and health service providers at the hospital. This was achieved through interviews with admitted persons as well as discussions with the hospital medical superintendent, public health officer, surveillance officer and the county director of veterinary services. This enabled determination of magnitude of the outbreak, case search and description and the circumstances surrounding the outbreak.

9 participants attended this activity with 7 males and 2 females. The institutions represented involved 5 from the University of Nairobi- faculty of Veterinary Medicine and 4 (self-sponsored) government officials from the Ministry.

Information on the whereabouts of suspected carcass was scanty. The outbreak investigation findings revealed that the disease in question was a case of human cutaneous anthrax from an infected bovine carcass. Seven cases were admitted and all were middle-aged males from Thika Sub-County, Kiambu County.  Five of the cases are licensed as meat carriers from the slaughter house and the two were abattoir herdsmen. Patients with cutaneous lesions of suspected anthrax were admitted in the isolation ward at the Thika Referral Hospital. Lesions were ranging from 2 to 10 cm in diameter, with pathognomonic eschars on forearms, with one case having a facial lesion below the left eye on the zygomatic arch. The dead cattle were suspected to be slaughtered on 29th April 2017 with the first symptoms appearing after approximately 24-48 hours. Most cases developed symptoms on 4th May 2017; hence the approximate incubation period was five days. All seven cases were responding well to ciprofloxacin and Doxycycline therapy. The slaughterhouse was closed down, licenses of the five containers revoked and destroyed, Quarantine imposed and mass vaccination of livestock underway. A stakeholder forum had been scheduled to take place soon.

The four undergraduate students from the University of Nairobi, who participated in the investigation, benefited immensely by being in the first line of response team.