Table 4.

Details on outbreaks detected through informal notifications (n = 15)

ID	Country, area, date of onset (references)	Aetiologic agent	Onset to detection (days)	Comments
21	Afghanistan, Bamian, Sep 2000 [48]	Plasmodium falciparum	*	A United Nations radio operator notified the alert. A similar outbreak had occurred undetected two to three years earlier.
22	Afghanistan, Taiwara District, Mar 2002 [49]	Scurvy	(46)	Isolation of the district during the winter months delayed detection. The outbreak was reported by an international NGO.
23	Angola, Uige Province, Mar 2005 [50-58]	Marburg virus	*	Concerns of an unusual severe illness were raised by hospital staff in October 2004. A poliomyelitis surveillance officer carried out the initial case investigation in November. Blood samples were sent for analysis at the CDC. Results were initially negative for any viral haemorrhagic fever. Low numbers of similar cases occurred over subsequent months. By 9 March 2005 the situation worsened, and the first death among health care staff occurred. New blood sampling confirmed Marburg on 21 March 2005. Travel by road was precarious, necessitating air transport. Retrospective analysis identified 102 cases dating back to October 2003. Fear and poor adherence to infection control procedures hampered control.
24	Central African Republic, Bangui, Jul 2002 [59]	Hepatitis E virus		A government chief medical officer reported people with jaundice dying of haemorrhage. Yellow fever was initially suspected. Investigation revealed symptoms suggestive of hepatitis. Laboratory tests confirmed Hepatitis E.
25	Chad, Jun 2005 [60]	Measles virus		A senior vaccination officer with MSF noticed a high incidence of measles being reported from health clinics, during a site visit. A surveillance system was in place, but the data were not being analysed.
26	DRC, Kinshasa, Jun 2003 [61]	Escherichia coli		An informal alert was raised by the Institut National de Recherche Biomedicale in Kinshasa in response to an increasing incidence of severe diarrhoea testing positive for E coli. An outbreak investigation could not be conducted at the time due to political unrest. A high case-fatality amongst infants at a city hospital was attributed to insufficient treatment, particularly haemodialysis, at the beginning of the outbreak.
27	DRC, Bosobolo district, Equateur Province, Nov 2002 [62]	Influenza virus	80	A local NGO reported the outbreak. The area was under the control of a rebel group. The public had little access to medical facilities. A large proportion of deaths could have been prevented with antibiotics.
28	DRC, Orientale Province, Jan 2005 [63]	Yersinia pestis	(28)	An informal alert of an epidemic, initially thought to be of haemorrhagic fever, was notified by local health providers in a camp for diamond miners.
29	Haiti, Petites Montagnes, 2004 [64]	Tunga penetrans		Health care facilities were up to 20 hours' walk away and at times unreachable. Clinical staff became aware of the outbreak relatively late, after receiving news brought by community health workers.
30	Myanmar, Yangon, 2001 [65]	Gnathostoma spinigerum		The outbreak occurred amongst Korean immigrants. The alert was raised by the Korean Embassy.
31	Republic of Congo, Mbomo, Nov 2003 [66,67]	Ebola virus	24	Red Cross volunteers informed local health authorities of a rumour of four suspicious deaths. A week later, a regional investigation team notified an alert of viral haemorrhagic fever to the central level. Impassable roads delayed the response team's arrival by 4 days. The response team was blamed for people dying and for bringing the disease. There was fear of isolation centres and at-home isolation kits were experimented with.
32	Republic of Congo, Impfondo, Likouala district, Jun 2003 [68]	Monkeypox virus	(65)	A physician treated several patients with pox-like lesions over a period of 3 weeks. Alarmed by the severity of the more recent cases, he sent photographs to colleagues from a city hospital of whom one was invited to assist with diagnosis and control. A week later, the outbreak was reported to the CDC and US embassy.
33	Somalia, Afmadow district, Lower Juba Region, Dec 2006 [69]	Rift Valley fever virus		In November 2006, warnings were issued of possible Rift Valley Fever outbreaks, following predictions by spatial models. On 19 December, the WHO received reports of suspected cases in Somalia. Violence, and later also a Kenyan border closure substantially delayed investigation. The virus was laboratory confirmed on 20 January. WHO's outbreak response teams in Nairobi worked closely with poliomyelitis surveillance officers and MSF in Somalia to investigate. Somali medical officers were provided with training on diagnosis and control by the WHO. Security deteriorations further hampered control efforts.
34	Sudan, Nuba mountains, South Kordofan state, 2002 [70]	West Nile virus		MSF operated the only health clinic available in the area, and notified the alert. Cases came from villages up to 8 hours' walk away.
35	Zimbabwe, Aug 2008 [71-73]	Vibrio cholerae		Due to collapsing health services, surveillance system completeness was estimated at 30%. The initial recognition of the epidemic was an increased number of cases of 'watery diarrhoea' being noted by Municipal Health Clinics. The ability of the Public Health Laboratory to confirm cholera was greatly limited by shortages of manpower and resources resulting from economic crisis. A second wave of the epidemic from Oct 2008 spread to all provinces and neighbouring countries. The Zimbabwean government declared an epidemic in Dec 2008.

* Investigation revealed previously undetected or undiagnosed outbreaks; () indicates that dates were estimated.