Yersinia pestis infection epidemiology and demographics

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Serge Korjian, Yazan Daaboul, Aravind Reddy Kothagadi M.B.B.S [2]

Overview

Given its ability to cause serious pandemics, plague is one of the three diseases subject to the International Health Regulations, the other two being yellow fever and cholera. From 1954 to 1997, plague affected 38 countries, with 80 613 cases and 6587 deaths.^[1] Between 2004 and 2009, the WHO reported that the number of cases of plague worldwide was 12,503, with 843 deaths, for a case-fatality rate of 6.7%.^[2]

Epidemiology and Demographics

Incidence

From 1954 to 1997, plague affected 38 countries, with 80 613 cases.^[1]

Between 2004 and 2009, the WHO reported that the number of cases of plague worldwide was 12,503.^[2]

Age

Patients of all ages are susceptible to disease; however, cases in the last few decades have been more common in children.^[3]

Gender

Patients of both sexes are susceptible to disease.^[3]

Mortality

Known as the black death, plague pandemics have caused significant casualties in the last 2 millennia. The first certain pandemic recorded in the sixth century AD spread across Asia, Africa and Europe claiming approximately 100,000,000 lives. The fourteenth century witnessed the second pandemic, with no less than 50,000,000 casualties. The third pandemic came in the late nineteenth century mostly affecting India with 13,000,000 recorded deaths.^[4]

From 1954 to 1997, plague affected 38 countries, with 6587 deaths.^[1]

Between 2004 and 2009, the WHO reported 843 deaths from plague and a case-fatality rate of 6.7%.^[2]

Geographic Distribution

Yersinia pestis in found in animal reservoirs, especially in rodents which are often responsible for the rapid spread of the disease. Natural foci of plague are found all over the world, particularly in tropical and sub-tropical latitudes and in warm regions of the temperate latitudes.
All continents are known to harbor natural plague foci except Australia.
It is important to note that natural foci of plague shift in response to changes in climate, landscape, and rodent population migration.^[1]


Chronology of Yersinia pestis infection Outbreaks(“WHO \| Plague”.)
Date	Region Affected	Suspected, Probable & Confirmed Cases	Deaths	Details
15 October 2017	Seychelles – Suspected Plague (Ex- Madagascar)	1	0	On 10 October 2017, the Seychellois Ministry of Health notified WHO of a probable case of pneumonic plague The probable case is a 34-year-old man who had visited Madagascar and returned to Seychelles on 6 October 2017. He developed symptoms on 9 October 2017 and presented to a local health centre(pneumonic plague infection suspected, isolated and treated) 11 October, rapid diagnostic test (RDT) preformed, sputum sample was weakly positive. October 9 to 11 2017, eight of his contacts developed mild symptoms and have been isolated October 13 was the last day of monitoring of over 320 contact persons of the probable case Contact tracing is done thoroughly and 577 children and 63 teachers in potential contact with one of the individual identified by contact tracing were given antibiotics.
2 October 2017	Madagascar	73	17	The outbreak started following the death of a 31-year-old male from Ankazobe District in the Central Highlands (Hauts-Plateaux), a plague-endemic area. Since then, the Ministry of Public Health of Madagascar enhanced field investigations, contact tracing, surveillance, and monitoring all close contacts As of 30 September, 10 cities have reported pneumonic plague cases and the three most affected districts include: the capital city and suburbs of Antananarivo (27 cases, 7 deaths), Toamasina (18 cases, 5 deaths), and Faratshio (13 cases, 1 death) In addition to the 73 cases of pneumonic plague, from 1 August to 30 September, 58 cases of bubonic plague including seven deaths have been reported. One additional case of septicaemic plague has also been reported, and one case where the type is not specified
29 September 2017	Madagascar	51	12	On 23 August 2017, a 31-year-old male from Tamatave, visiting Ankazobe District in central highlands, developed malaria-like symptoms. On 27 August, he developed respiratory symptoms during his journey in a shared public taxi from Ankazobe District to Tamatave (via Antananarivo). His condition worsened and he died. In addition to the 51 suspected, probable and confirmed cases of pneumonic plague, and during the same period another 53 cases of bubonic plague including seven deaths have been reported throughout the country. One case of septicaemic plague has also been identified and they were not directly linked to the outbreak. Additionally, 31 people who came into contact with this case either through direct contact with the primary case or had other epidemiological links, became ill, and four cases of them died The outbreak was detected on 11 September, following the death of a 47-year-old woman from Antananarivo, who was admitted to a hospital with respiratory failure caused by pneumonic plague
9 January 2017	Madagascar	62 cases (6 confirmed, 5 probable, 51 suspected)	26 (case fatality rate of 42%)	Of the 11 samples tested, 5 were positive for plague on rapid diagnostic test and 6 are now confirmed at Institut Pasteur laboratory. Of the total reported cases, 5 are classified as pneumonic plague cases and the remaining as bubonic plague Retrospective investigations carried out in those two districts showed that it is possible that the outbreak might have started in mid-August 2016. The investigation in neighbouring villages is still ongoing. On 29 December, an investigation carried out within 25 km of the initial foci in Befotaka district has reported three deaths and is being investigated further for possible linkage to the outbreak
6 September 2015	Madagascar	14	10	The Ministry of Health of Madagascar has notified WHO of an outbreak of plague. The first case was identified on 17 August in a rural township in Moramanga district. The case passed away on 19 August All confirmed cases are of the pneumonic form. Since 27 August, no new cases have been reported from the affected or neighbouring districts
21 November 2014	Madagascar	119	40	On 4 November 2014, WHO was notified by the Ministry of Health of Madagascar of an outbreak of plague. The first case, a male from Soamahatamana village in the district of Tsiroanomandidy, was identified on 31 August. The patient died on 3 September Only 2% of reported cases are of the pneumonic form Cases have been reported in 16 districts of seven regions. Antananarivo, the capital and largest city in Madagascar, has also been affected with 2 recorded cases of plague, including 1 death. There is now a risk of a rapid spread of the disease due to the city’s high population density and the weakness of the healthcare system. The situation is further complicated by the high level of resistance to deltamethrin (an insecticide used to control fleas) that has been observed in the country
10 August 2010	Peru	17	–	As of 30 July 2010, the Ministry of Health in Peru confirmed a total of 17 cases of plague in Ascope province of Department La Libertad. Of these, four are pneumonic plague, 12 are bubonic plague and one was septicemic plague. The onset of symptoms for the last reported case of pneumonic plague was on 11 July 2010. During the investigations, 10 strains of Y. pestis were isolated from humans, rodents and domestic cats
11 August 2009	China	12	3	On 1 August 2009, a cluster outbreak of pulmonary plague cases in the remote town of Ziketan, Qinghai province was reported by the Ministry of Health (MoH), China. On 26th July 2009, the first case was a 32 year old male herdsman, who developed fever and hemoptysis was reported. He died enroute to hospital. On 30 July, 11 people who had close contact with the case (mainly relatives who attended the funeral) were all hospitalized as they developed fever and cough. They were all tested positive for plague. On 2 August 2009, 2 people who helped to bury the corpse, 64 year old father-in-law of the first case and a 37 year old male neighbour of the first case also died. On August 6 2009, the local health authority isolated 332 close contacts for further medical observation, and implemented traffic control around affected area. Preventive measures were taken to stop teh spread. Epidemiological investigation showed that the source of this outbreak was a wild marmot, which had contact with the dog of the index case.
7 November 2006	Democratic Republic of the Congo	1174	50	As of 29 September 2006, WHO received reports of a suspected pneumonic plague outbreak in 4 health zones in Haut-Uele district, Oriental province in the north-eastern part of the country. More than 50 samples have been collected and analysed; however, the diagnosis of plague has not been finally laboratory confirmed.
13 October 2006	Democratic Republic of the Congo	626	42	WHO has received reports of a suspected pneumonic plague outbreak in 2 health zones in Haut-Uele district, the majority reported from Wamba health zone in Oriental province in the northern part of the country However, the low case fatality ratio is unusual for pneumonic plague which suggests that the number of suspected cases may be an overestimation Preliminary results from a rapid diagnosis test in the field found three samples positive, out of eight
14 June 2006	Democratic Republic of the Congo	100	19	Suspected cases of bubonic plague have also been reported but the total number is not known at this time. Preliminary results from rapid diagnostic tests in the area confirm pneumonic plague. Ituri is known to be the most active focus of human plague worldwide, reporting around 1000 cases a year. The first cases in this outbreak occurred in a rural area, in the Zone de Santé of Linga, in mid-May
15 March 2005	Plague in the Democratic Republic of the Congo – update 4	130	57	Reported in Zobia, Bas-Uélé district, Oriental province No cases of bubonic plague have been detected
9 March 2005	Plague in the Democratic Republic of the Congo – update 3	114 cases (110 suspect cases, 4 probable cases)	54	Reported in Zobia, Bas-Uélé district, Oriental province
4 March 2005	Plague in the Democratic Republic of the Congo – update 2	57 cases (54 suspect cases, 3 probable cases)	16	Reported in Zobia, Bas-Uélé district, Oriental province
1 March 2005	Plague in the Democratic Republic of the Congo – update	4 probable cases and 4 suspect cases	1	Reported in Zobia, Bas-Uélé district, Oriental province
18 February 2005	Plague in the Democratic Republic of the Congo	–	61	Reported in Bas-Uele district, Oriental province Preliminary results from rapid diagnostic tests in the area confirm pneumonic plague, and the cases had clinical features compatible with this disease Cases have occurred in workers in a diamond mine in Zobia where c. 7000 people work. The mine was re-opened on 16 December 2004 and the first case occurred on 20 December
10 July 2003	Plague in Algeria – Update 2	10 laboratory confirmed cases and 1 probable case	–	Reported in oran district
3 July 2003	Plague in Algeria – Update	10 cases of which 8 have been laboratory confirmed	–	Reported by Ministry of Health, Algeria 8 cases of bubonic plague and 2 of septicemic plague, of which one was fatal
24 June 2003	Plague in Algeria	10 cases, 8 cases of bubonic plague and 2 of septicemic plague	one fatal case reported	Reported by the Ministry of Health, Algeria in Tafraoui, on the outskirts of Oran
5 June 2002	2002 – Plague in Malawi	71	–	Reported by the Malawian Ministry of Health 71 cases of bubonic plague in the district of Nsanje since the onset of the outbreak on 16 April 2002 Outbreak has so far affected 26 villages, 23 in the Ndamera area, 2 in Chimombo and 1 village in neighbouring Mozambique
20 February 2002	2002 – Plague in India	16 cases of pneumonic plague	4 deaths in Hat Koti village	Reported by the Ministry of Health, India
26 March 2001	2001 – Plague in Zambia	23 hospitalized cases	3 deaths in Petauke district, Eastern Province	The last case reported was 15 March 2001

Shown below is a picture depicting the global distribution of natural plague foci as of March 2016

References

↑ ^1.0 ^1.1 ^1.2 ^1.3 World Health Organization (1999). “Plague Manual: Epidemiology, Distribution, Surveillance and Control”. WHO/CDS/CSR/EDC.
↑ ^2.0 ^2.1 ^2.2 “Human plague: review of regional morbidity and mortality, 2004-2009”. Wkly Epidemiol Rec. 85 (6): 40–5. 2009. PMID 20151494.
↑ ^3.0 ^3.1 Butler T (2009). “Plague into the 21st century”. Clin Infect Dis. 49 (5): 736–42. doi:10.1086/604718. PMID 19606935.
↑ Cohn SK (2008). “Epidemiology of the Black Death and successive waves of plague”. Med Hist Suppl (27): 74–100. PMC 2630035. PMID 18575083.CS1 maint: PMC format (link)

Template:WikiDoc Sources

[who-1] 1.0 ^1.1 ^1.2 ^1.3 World Health Organization (1999). “Plague Manual: Epidemiology, Distribution, Surveillance and Control”. WHO/CDS/CSR/EDC.

[pmid20151494-2] 2.0 ^2.1 ^2.2 “Human plague: review of regional morbidity and mortality, 2004-2009”. Wkly Epidemiol Rec. 85 (6): 40–5. 2009. PMID 20151494.

[pmid19606935-3] 3.0 ^3.1 Butler T (2009). “Plague into the 21st century”. Clin Infect Dis. 49 (5): 736–42. doi:10.1086/604718. PMID 19606935.

[pmid18575083-4] Cohn SK (2008). “Epidemiology of the Black Death and successive waves of plague”. Med Hist Suppl (27): 74–100. PMC 2630035. PMID 18575083.CS1 maint: PMC format (link)

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