Cluster Outbreak of Acute Respiratory Illness in Kampala, February 2017

Summary

An outbreak of acute flu like illness was reported on 22^nd Feb to Ministry of Health. The index case was an expatriate working for a multinational company in Kampala. He developed symptoms of acute fever and headache after a return from a trip to the Middle East. He was managed in two private hospitals in Kampala and subsequently airlifted to Nairobi Hospital when his condition deteriorated despite treatment. His nine year old son, and the only other case in the family, who attended an International School in Kampala also developed similar symptoms and was admitted in a private hospital in Kampala. He was also airlifted to Nairobi Hospital. Laboratory tests confirmed Influenza A (pH1N1) for both the index case and his son. The only other suspected case and a co-worker of the index case who developed fever and cough tested negative for H1N1 but had a neutrophilia and was managed as a bacterial infection. Contact tracing of individuals and health workers who interacted with case-persons yielded nothing significant. In conclusion, this was a cluster outbreak of pH1N1 which was self-limiting.

Introduction

On 22^nd Feb 2017, Ministry of Health through PHEOC an expatriate who developed acute flu like illness a few days earlier, managed at the hospital but later airlifted to Nairobi Hospital. The son of the expatriate similarly developed acute flu-like symptoms; was managed at private hospital in Kampala for a few hours and later airlifted to Nairobi Hospital. A co-worker of the index case at the Country Office developed acute fever and headache and was admitted at the same private hospital in Kampala. Based on the above information; a team from Ministry of Health set out to conduct an epidemiologic investigation to identify the cause, mode of transmission and recommend control measures for this outbreak.

Methods

We contacted the management of the private hospitals where the cases were admitted and man- aged to obtain firsthand information. We also met the administration of the organization at their Country Office and obtained updates on the chronology of events.

We defined a Suspected Case as a resident or visitor of Kampala with acute onset of fever, sore throat and cough with one of the following symptoms: headache, body weakness and difficulty in breathing, and a Confirmed Case was a suspected case with laboratory confirmation of the causative pathogen.

We conducted active case search by reviewing records in hospitals where the suspected case-persons were admit- ted, investigated and treated. Interactions with doctors in hospitals which have Intensive Care Units in Kampala was done. More information on the travel and exposure history of the index case-person and family were got. Laboratory tests were conducted on all the case-persons.

Findings

In Nairobi, samples obtained from the de- ceased index case-person (Mr. A) all tested positive for pH1N1 Influenza. The son to the index case also tested positive for Influenza A. Both the index case and son were negative for MERS-CoV, haemorhagic fevers and other sub-types of Influenza A. Lab tests done at KEMRI (27^th Feb) confirmed that the index case was positive for Influenza A (pandemic flu H1N1) as was the son. Specimens were lung aspirate for the index case and a naso-pharyngeal swab for the son.

In Kampala, lab results on the index case were as follows: Initial CBC was normal and no malaria parasites were detected. Subsequent investigations revealed a low WBC count (Severe Leucopenia) and Chest X-ray showed consolidation in the lungs. The D-dimer was high at 3568.8 which was an indication of a possible pulmonary embolism. Laboratory findings of co-worker (Mr. B), tested 24^th Feb 2017 at UVRI: CBC, LFT, serum electrolytes, urea, creatinine, CRP were all normal and the test for MERS-CoV and Influenza A were negative.

Sequence of Events

The index patient, Mr. A, was a 46- year old male expatriate and an employee of a non-governmental organization in Uganda. He traveled to the Middle East on Sat 11^th Feb 2017 for holiday with his family of 5, (his wife, a son and 2 daughters). He traveled from Uganda (Entebbe) UAE (Dubai) via Kenya (Nairobi). The family stayed in Dubai for a week (11th -18^th Feb 2017). Information on activities conducted during the vacation is scanty, however, it was reported that Mr. A and his son came into contact with a camel at some point. Detailed information on interaction with the camel was not clear. The family returned to Uganda on 18^th Feb 2017 and he stayed home on Sunday 19^th Feb 2017. On the 20^th Feb 2017, Mr.

A reported to office in Kampala and held a series of meetings. During the third meeting, colleagues noted that he was shivering. Later he disclosed to a friend that he had developed fever, headache, cough and difficulty in breathing. He was taken to a private hospital by a company driver who by the time of investigations was in good health; a series of laboratory tests were done. His symptoms were: general body weakness, headache, shivering, fever 38.8°C, sore throat, running nose, mild dry cough; he was diagnosed with acute pharyngitis. While at home on Tuesday 21^st Feb. 2017, his temperature shot up and he was taken back to the hospital where he was found to have leucopenia and temperature of 37.3°C which rose to 41°C within a short time. He developed general body weakness and severe respiratory distress and needed respiratory support.

He had abnormal chest X-ray and was airlifted to Nairobi Hospital from where he died the following day, 22^nd Feb 2017. Postmortem revealed fulminant pneumonia and multi-organ failure. The 9year old son of the index case was admitted at a private hospital on 22^nd Feb 2017 at 10pm with a high fever, sore throat, mild cough, general body weaknesses and difficulty in breathing. He only spent about 4 hours at the hospital and with a deteriorating condition a decision was taken to airlift him to Nairobi Hospital. Earlier on Monday 20^th Feb. 17, the boy attended school at an International School in Kampala without any complaints.

Contact Tracing

The domestic worker to Mr. A, a 30yr old female Uganda national was interviewed. She said she only came to Mr. A’s residence on Tuesday 21st Feb. 2017 and had no direct contact with Mr. A. She was by 2^nd March 2017 in good health with no flu-like symptoms. Her other family members were reportedly fine as well. Follow up in the International School revealed nothing remarkable. A list of co-workers at the Country Office and health workers at the private hospitals who had contact with Mr. A was generated and monitored for possible symptoms.

None of them had by 02^nd March 2017 developed any sudden onset of fever, cough, or sore threat suggestive of pandemic flu. No cases were reported in all Intensive Care Units in Kampala.

Time, Place and Person Characteristics

A cluster of 3 case-persons in close contact with one death were line- listed, Case Fatality Rate = 33% (1/3). The index case traveled with the son and shook the hand of the Co-worker on Monday. All case-persons were males. Both the survivors are currently stable and symptom free. All the case persons had fever (100%). The other symptoms were distributed as follows: headache (67%), sore throat (67%) and difficulty in breathing (67%).

Autopsy Results

The autopsy performed on the de- ceased index case revealed fulminant pneumonia and multiple organ failure.

Conclusion

The most probable pathogen responsible for this outbreak was pH1N1 Influenza. The infection was limited to the cluster and did not spread to other members who came in contact with the case persons.

Public Health Actions and Recommendations

The following public health actions were instituted:

• Follow up the contacts who were listed in Kampala
• Notification of WHO
• Education of the public and health personnel on hand hygiene and cough etiquettes
• Weekly reporting from the Emergency Operations Centre
• Notification of clinicians in health facilities within Kampala and surrounding areas to have a high index of suspicion when patients report with acute flu-like illness
• The National Task Force declared the outbreak confined to a cluster without spread to other members of the community

We recommended:

• Strengthening surveillance system for influenza in the country
• Preparing pamphlets for education of the health personnel and general public on Influenza