WHO SOUTHERN SUDAN HEALTH UPDATE May 2004

Transcription

1 WHO SOUTHERN SUDAN HEALTH UPDATE SPECIAL EDITION: EBOLA Ebola outbreak confirmed in Yambio, Western Equatoria World Health Organization leads international response team to contain the outbreak Photo by: P. F. Fig. : VHF patient with skin rash & soft palate hemorrhages, Yambio WEQ Outbreak of Ebola reported in Yambio, Western Equatoria On Thursday 6 th, the WHO/EWARN Office in Lokichoggio received a radio message from the WHO Public Health Coordinator for Equatoria Region reporting an outbreak of an unusual disease in the Hai-Cuba section of Yambio town. The first case was a young man aged 7 years admitted to Yambio Hospital on il 8 th, with a history of epigastric pain, fever, headache, general body pain, skin rash, chest pain, cough, diarrhea with blood, vomiting with blood and bleeding from the nose and mouth. His illness started on il th, and he died on il nd,. After the death of the first case, other contacts developed the same disease. They included his parents and close relatives who took part in preparing the body for burial; friends who cared for him in the hospital and at home; and two nurses who treated him in the hospital. The father of the first case died on th. At the time it was reported that the total number of cases was 7 including deaths. A team from WHO South Sudan and the Kenya Medical Research Institute (KEMRI) conducted the initial field investigation from 9-. The team was joined in the field by

2 UNICEF/Health, DOY/CORDAID and the County Health Department. At the time of the investigation, patients (including deaths) had occurred. The team carried out interviews with key informants, took patient histories, conducted clinical and epidemiological assessments, and collected specimens (blood, urine and stool). The specimens were sent to referral laboratories in KEMRI and the Centers for Disease Control and Prevention (CDC), to confirm the suspicion of a viral hemorrhagic fever outbreak. The causative organism was identified as Ebola virus group Sudan. Ten out of twelve suspected cases whose specimens were sent for laboratory analyses tested positive for Ebola Sudan. By June, the total number of confirmed and probable cases had reached 7 including 7 deaths. 7 6 Ebola outbreak in Yambio, Sudan, il-june, 7cases including 7 deaths (CFR 6%). Number of cases 9- Mar survivors deaths Time(in week) Karthoum Yambio / medical staff infected Fig. : Epidemic curve, EHF outbreak Yambio, il June, 6 EHF cases (n=) by transmission generation, il-, Yambio, South Sudan rd nd st index Fig. : Yambio VHF Epicurve by transmission generation Ebola outbreak in Yambio, Sudan, il - June, 7cases including 7 deaths : Transmission tree Index cases st generation World Health Organization and partners working hard to contain Ebola Hemorrhagic Fever in South Sudan. nd generation rd generation th generation ? Fig. : Transmission tree, EHF outbreak, Yambio, il-june

3 Historical review of Ebola in Sudan Introduction Ebola virus belongs to the Filoviridae family and is comprised of four distinct subtypes: Zaïre, Sudan, Côte d Ivoire and Reston. The three subtypes occurring in Africa (Zaïre, Sudan and Côte d Ivoire) have been identified as the cause of ebola hemorrhagic fever (EHF), a febrile, often hemorrhagic illness with a high fatality ratio. Ebola Reston has always been asymptomatic in humans. Since 976, Ebola Zaïre, Sudan and Côte d Ivoire viruses have been responsible for several epidemics or isolated cases of EHF in DRC, Gabon, the Republic of Congo, Sudan, Uganda and Côte d'ivoire. The last EHF outbreaks were reported in northern Uganda in, a large outbreak due to Ebola Sudan, and in eastern Gabon and western Congo in late, several outbreaks due to slightly different strains of Ebola Zaire.... Nzara and Yambio, 979 Between July and 6 October 979, cases (including deaths, case fatality ratio 6%) of Ebola (Sudan strain) were reported in five families in the towns of Nzara and Yambio. The disease was introduced into four families from a local hospital. The spread of the disease occurred during the management of the patients at the hospital or at home. Chains of transmission within family units accounted for 9 cases resulting from direct physical contact with an infected person. The index case worked in the cotton factory of Nzara. The investigation identified three cases among other employees of the factory but they were infected following contact with identified cases. The investigation of this outbreak confirmed the finding of previous studies that there was no risk of airborne transmission for Ebola. Nzara and Maridi, 976 The history of Ebola virus infections began in June 976 in southern Sudan with a large outbreak of Ebola hemorrhagic fever. There were a total of 8 cases (including deaths); 67 in the source town of Nzara, in Maridi, in Tambura and in Juba between June and November 976. The outbreak in Nzara appears to have originated among the workers of a cotton factory. The disease in Maridi was amplified by transmission in a large, active hospital. Transmission of the disease required close contact with an acute case and was usually associated with the act of nursing a patient. The incubation period was between 7 and days. The disease was characterized by a high case fatality ratio (%) and a prolonged recovery period in those who survived. Beginning with fever, headache, joint and muscle pain, the disease soon caused diarrhea (8%), vomiting (9%), chest pain (8%), pain and dryness of the throat (6%) and rash (%). Hemorrhagic manifestations were common (7%). The outbreak in Sudan was due to a strain baptized Ebola Sudan. The investigation identified index cases who were all working in the cloth room of the cotton factory in Nzara. Ecological studies failed to discovered the source of the outbreak. Fig. : Epidemic curve, EHF outbreak, Nzara and Maridi, 976.

4 Ebola outbreak in Sudan, July-October 979, cases including deaths (CFR 6%). HCW Family A Family B Family C Family D Family E -Jul -Aug -Aug -Sep 6-Sep 8-Sep Karthoum Nzara Yambio medical staff infected intrafamilial and nososcomial transmission Fig. 6: Epidemic curve, EHF outbreak, Nzara, 979. National and International response Posters Radio Community Discussion Mobile Teams roads police Traditional healers Medical Anthropology Social Mobilization and Health Education Logistics and Security salaries Transports Vehicles Coordination Media Burial Teams Screening Case Management and Funerals Surveillance Epidemiology Laboratory Data Management & Reporting Reporting Results Barrier Nursing Patient Care Environment Contact Tracing Case Finding Sample Collection Testing Fig. 7: Response structure, EHF outbreak, Yambio, il June. WHO and partners respond to EHF outbreak in WEQ Following confirmation of Ebola, partners from the Global Outbreak Alert and Response Network (GOARN joined WHO staff on 9 il, providing additional on-site expertise in VHF case management, surveillance, laboratory, social mobilisation and logistics. Partner institutions included WHO Geneva and Tunis, CDC Atlanta, EPIET and FETP Egypt. MSF France established an isolation ward and together with the Medical Superintendent of Yambio Civil Hospital and the Diocese of Tambura/Yambio lead the case management team. - Treat cases with strict infection control measures - Enable safe transport to isolation ward - Conduct safe burials. Surveillance and Contact tracing - Establish surveillance system (active case finding). Follow all contacts of cases for days after last exposure and isolate if ill. Logistics and security A County Crisis Management Committee was established under the chairmanship of the SPLM County Secretary. Four subcommittees were formed to work under this committee:. Social mobilisation, health education - Restrict all practices that promote transmission at community level. Case management and burial - Isolate and treat cases - Establish isolation ward

5 Ebola Haemorrhagic Fever Excerpts WHO Fact sheet N, Revised Ebola virus, Filoviridae family, is comprised of four distinct subtypes: Zaïre, Sudan, Côte d Ivoire and Reston. Three subtypes, occurring in the Democratic Republic of the Congo (formerly Zaire), Sudan and Côte d Ivoire, have been identified as causing illness in humans. Ebola haemorrhagic fever (EHF) is a febrile haemorrhagic illness which causes death in -9% of all clinically ill cases. Human infection with the Ebola Reston subtype, found in the Western Pacific, has only caused asymptomatic illness, meaning that those who contract the disease do not experience clinical illness. The natural reservoir of the Ebola virus seems to reside in the rain forests of the African continent and in areas of the Western Pacific. Transmission? The Ebola virus is transmitted by direct contact with the blood, secretions, organs or other bodily fluids of infected persons.? Burial ceremonies where mourners have direct contact with the body of the deceased person can play a significant role in the transmission of Ebola.? The infection of human cases with Ebola virus has been documented through the handling of infected chimpanzees, gorillas, and forest antelopes--both dead and alive--as was documented in Côte d'ivoire, the Republic of Congo and Gabon. The transmission of the Ebola Reston strain through the handling of cynomolgus monkeys has also been reported.? Health care workers have frequently been infected while treating Ebola patients, through close contact without the use of correct infection control precautions and adequate barrier nursing procedures. Incubation period: two to day s. Symptoms Ebola is often characterized by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat. This is often followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding. Laboratory findings show low counts of white blood cells and platelets as well as elevated liver enzymes. Therapy and vaccine? Severe cases require intensive supportive care, as patients are frequently dehydrated and in need of intravenous fluids or oral rehydration with solutions containing electrolytes.? No specific treatment or vaccine is yet available for Ebola haemorrhagic fever. Several vaccine candidates are being tested but it could be several years before any are available. A new drug therapy has shown early promise in laboratory studies and is currently being evaluated further. However, this too will take several years.? Experimental studies involving the use of hyper-immune sera on animals have demonstrated no protection against the disease. Containment? Suspected cases should be isolated from other patients and strict barrier nursing techniques implemented.? Contact tracing and follow-up of people who may have been exposed to Ebola through close contact with other cases is essential.? All hospital personnel should be briefed on the nature of the disease and its routes of transmission. Particular emphasis should be placed on ensuring that invasive procedures such as the placing of intravenous lines and the handling of blood, secretions, catheters and suction devices are carried out under strict barrier nursing conditions. Hospital staff should have individual gowns, gloves, masks and goggles. Non-disposable protective equipment must not be reused unless they have been properly disinfected.? Infection may also be spread through contact with the soiled clothing or bed linens from a patient with Ebola. Disinfection is therefore required before handling these items.? Communities affected by Ebola should make efforts to ensure that the population is well informed, both about the nature of the disease itself and about necessary outbreak containment measures, including burial of the deceased. People who have died from Ebola should be promptly and safely buried. Contacts? As the primary mode of person-to-person transmission is contact with contaminated blood, secretions or body fluids, any person who has had close physical contact with patients should be kept under strict surveillance, i.e. body temperature checks twice a day, with immediate hospitalization and strict isolation recommended in case of the onset of fever.? Hospital personnel who come into close contact with patients or contaminated materials without barrier nursing attire must be considered as contacts and followed up accordingly. Natural reservoir? The natural reservoir of the Ebola virus is unknown despite extensive studies, but seems to reside in the rain forests on the African continent and in the Western Pacific.? Although non-human primates have been a source of infection for humans, they are not thought to be the reservoir. They, like humans, are believed to be infected directly from the natural reservoir or through a chain of transmission from the natural reservoir.? On the African continent, Ebola infections of human cases have been linked to direct contact with gorillas, chimpanzees, monkeys, forest antelope and porcupines found dead in the rainforest. So far, the Ebola virus has been detected in the wild in carcasses of chimpanzees (in Côte-d Ivoire and Republic of Congo), gorillas (Gabon and Republic of Congo) and duikers (Republic of Congo).? Different hypotheses have been developed to try to explain the origin of Ebola outbreaks. Laboratory observation has shown that bats experimentally infected with Ebola do not die, and this has raised speculation that these mammals may play a role in maintaining the virus in the tropical forest.? Extensive ecological studies are underway in the Republic of Congo and Gabon to identify the Ebola's natural reservoir.