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Archive for the ‘Outbreaks’ Category

Diphtheria in Latvia

Following a regional epidemic during the 1990’s, Latvia has continued to experience a high incidence of diphtheria. [1]  This phenomenon is difficult to explain on the basis of poor vaccine uptake. The following graph compares W.H.O. estimates of vaccination (DPT3) coverage with diphtheria rates reported in Estonia, Latvia and Lithuania. [2]



1. Berger SA. Infectious Diseases of Latvia, 2015. 436 pages, 103 graphs, 1,497 references. Gideon e-books,

2. Berger SA. Diphtheria – Global Status, 2015. 333 pages, 445 graphs, 374 references. Gideon e-books,



Note featured on ProMED


Arthropod-borne Viruses of Senegal

A recent outbreak of suspected viral infection in Kedougou Region ( highlights the complexity of establishing a specific etiological agent in West Africa.  At least twenty arthropod-borne viruses are associated with known or suspected human infection in Senegal.  The following alphabetical list is abstracted from Gideon and the Gideon e-book series [1]   (Primary references are available from Dr. Berger on request)

Bagaza – Bagaza virus has been recovered from mosquitoes in Senegal (Aedes fowleri, Culex neavei, Cx. Poicilipes and Mansonia, Mimomyia hispida, M. lacustris, M. splendens and Aedeomyia africana.

Bangui – Bangui virus was identified in mosquitoes in the Senegal River basin in 1988.

Bunyamwera – Bunyamwera virus has been identified in mosquitoes in the Barkedji region.

Chandipura – Chandipura virus has been identified in mosquitoes in the Barkedji region, and in phlebotomines in the Kedougou district.

Chikungunya – Outbreaks of Chikungunya were reported in Senegal in 1966, 1977, 1982, 1988, 1992, 1996 and 1997.  In 2006, a cluster of six cases in France was reported among travelers returning from Senegal. The virus has been found in a variety of local mosquito species, notably Aedes furcifer-taylori, Ae. luteocephalus, Ae. dalzieli and Stegomyia (Aedes) aegypti. Additional vectors may include Ae. vittatus, Anopheles rufipes and An. coustani.

Dengue – An outbreak of dengue was reported in Senegal during 1927 to 1928; and circulation of the virus was subsequently confirmed in 1974 and during 1999 to 2000. An epizootic among monkeys was reported in 1981; and the first human case was reported in 1983 (from Casamance). Several human and monkey infections were reported in 1990. In 2009, a dengue outbreak (196 cases, 1 fatal) was reported – the first reports of human dengue in Senegal for two decades. Italy reported a case of dengue hemorrhagic fever, imported from Senegal, and cases of dengue fever have been confirmed among French military personnel serving in this country.

Gabek Forest – Gabek Forest virus, a Phlebovirus, has been identified in sandflies (Phlebotomus species) in Senegal (1990 to 1995).

Koutango – Koutango virus (similar to Spondweni virus) has been identified in mosquitoes (Culex neavei) in the Barkedji region.

LeDantec – LeDantec virus is a rhabdovirus which is distinct from the vesicular stomatitis group 1. A single case of infection was reported in Senegal in 1965.

Ngari – Ngari virus has been identified in mosquitoes in the Barkedji region.  Two cases of Ngari virus infection were reported from Dakar,

O’nyong nyong – Although specific data are lacking for Senegal, circulation of O’nyong nyong virus is reported in this region of West Africa.

Rift Valley fever (RVF) – RVF virus was first isolated in West Africa in 1974, from Aedes (Aedimorphus) dalzieli in Senegal. Highest seroprevalence rates are found in the northwest and northcentral regions. Serological studies suggest that the disease was active in Diawara and Bakel (Eastern region) in 1998. Outbreaks were reported among goats, sheep and / or cattle in 2002, 2003, 2013 and 2014.  Carriage by mosquitoes and seroprevalence among sheep in the northern region increased during the 1990’s. Rift Valley virus was identified in mosquitoes in Barkedji in 1993, and re-emerged in 2002. A single isolated case of human Rift Valley fever was confirmed in a school teacher in Kedougou in 2012.

Rift Valley fever virus – seroprevalence surveys:

22.3% of Peul people of the North-central region

15.3% of the population in the Senegal River basin (1995 to 1996)

5% of children born after 1987, vs. 25.3% of the older population in Podor District (1999 publication)

5.2% of individuals in Diawara (1999)

2.9% of small ruminants tested in the Ferlo region (2003)

24.4% of sheep and goats in the Senegal River basin in 1988, 19.3% in 1989

17.2% of ungulates in the Senegal River Basin (1990)

3.8% of wild rodents, notably Rattus rattus, Mastomys huberti, A. niloticus and M. erythroleucus (2000 publication)

Semliki Forest – Semliki Forest virus has been recovered from mosquitoes (Aedes vittatus) and ticks (Rhipicephalus guilhoni) in Senegal.

Tataguine – Antibody toward Tataguine virus is found in 57% of the population.

Usutu – Zoonotic infection by Usutu virus has been identified in Senegal.

Wesselsbron – Seropositive humans were documented in Senegal during 1972 to 1975; and the virus itself has been identified in mosquitoes (Aedes vexans) in the Barkedji region.

West Nile – Seroprevalence rates for West Nile virus of 78.3% to 92% have been reported among horses. Infection of wild birds and dogs has also been identified. Vector mosquito species in this country are thought to include Culex neavei, Cx. tritaeniorhynchus, Cx. modestus, Cx. perfuscus group, Cx. poicilipes, Aedes vexans, Mimomyia hispida, Mi. lacustris, Mi. splendens, Aedeomyia africana and Mansonia uniformis

Yellow fever – Epidemics of yellow fever were reported in Senegal in 1768, 1769, 1778 to 1779 (50 deaths among Caucasians), 1814, 1816, 1828, 1830, 1837, 1840 to 1841, 1844, 1852, 1858, 1863, 1866, 1872, 1900 to 1901 (225 fatal cases) and 1923 to 1927. Aedes furcifer, A. metallicus and A. luteocephalus are involved in the wild vertebrate transmission cycle in this country. Yellow-fever activity among mosquitoes in Senegal has been used to monitor potential human disease in West Africa. Infected mosquitoes were identified during 1976 to 1979, 1983, 1987, 1989, 1990, 1992, 1993 and 2010.  Chronology of recent Yellow fever outbreaks in Senegal:

1965 – 243 cases were reported in Diourbel.

1965 to 1966 – 2,000 to 20,000 cases and 200 to 2,000 deaths were estimated.

1979 – Two French tourists contracted fatal yellow fever in Senegal.

1995 – Cases reported in Ribo-Escale and Guente-Pate Districts (vicinity of Koungheul).

1996 – Highest number of cases for any country (30.2% of the world’s total), including an epidemic centered at Kaffine town. {p 9855398}

2001 – Three cases were reported in Kedougou District (Health Ministry report not included in WHO data).

2002 – An outbreak (78 cases, 11 fatal) was reported – with 18 cases in Diourbel and Ziguinchor regions, and 60 cases in Touba, Mbacke and Bambey districts, Diourbel region; Gossas and Fatick districts, Fatick region; Tambacounda district in Tambacounda region; Louga, Koulda and Dakar regions.

2005 – Activity was reported in Tambacounda region (Goudiri, Kadira)

2010 – Two Senegalese fishermen acquired yellow fever in Gambia.

2011 – Three cases were reported in Kedougou and Saraya Health districts, near the borders with Mali and Guinea Conakry.

Zika – There is evidence for the occurrence of yearly epizootics of Zika virus infection in Senegal. In 2008, two American scientists contracted Zika in the country. Natural infection has been identified in two local primate species, Cercopithecus aethiops and Erythrocebus patas; and in 1.82% of mosquito pools (2011).

Zinga – Zinga virus, a variant of RVF virus, has been identified in humans and mosquitoes in Senegal.



  1. Berger SA. Infectious Diseases of Senegal, 2015. 449 pages, 55 graphs, 1,864 references.  Gideon e-books,

Fifth Disease in Japan

The following background material on Fifth Disease in Japan is abstracted from Gideon and reference 1   Primary references are available on request to the author.
Epidemics of Parvovirus B19 infection occurred in Japan every ten years prior to 1980, and every five years since 1981.  Most cases occur during spring and summer, with highest rates among children ages 5 to 9 years.   See graph:


Parvovirus B19 infection causes an estimated 107 fetal deaths and 21 hydrops fetalis cases per year (2014 publication)
Eight cases of transfusion-associated Parvovirus B19 infection were reported during 1999 to 2008.

Prevalence surveys:
10% of nonimmune hydrops fetalis cases (1994 publication)

Seroprevalence surveys:
67.9% of healthy residents of Kyushu and Okinawa (IgG, 2013 publication)

2% of children ages 0 to 9 in 1973 and 16% in 1984

67% ages 20 to 29 in 1973 and 20% in 1984

80% ages 30 to 39 in 1973 and 56% in 1984

33% of pregnant women in Miyagi Prefecture in 1987, and 46% in 1997

Published outbreaks:
1977 to 1981 – Outbreaks of erythema infectiosum were reported – including 395 cases in one district of Tokyo.
1985 (publication year) – An outbreak of erythema infectiosum was reported.
1986 to 1987- Outbreaks of erythema infectiosum were reported.
1993 (publication year) – An outbreak of erythema infectiosum was reported among hospital staff members.
2000 (publication year) – An outbreak (10 cases) of nosocomial Parvovirus B19 infection was reported.

1. Berger S. Infectious Diseases of Japan, 2015. 632 pages, 166 graphs, 3,706 references. Gideon e-book series,

Pertussis: Global Trends in Incidence and Vaccine Uptake

Recent pertussis outbreaks are of concern, but should not overshadow a dramatic decrease in disease rates documented during the past three decades. [1] In the following chart, I’ve compared regional trends in pertussis reporting and W.H.O. estimates of vaccine uptake [2] Note that vaccine coverage has changed little since 1990.


2. Berger S. Pertussis: Global Status, 2013. 353 pages, 511 graphs, 648 references. Gideon e-books,

Trichinosis: Cross-border Episodes

A recent trichinosis outbreak in Belgium related to Spanish boar meat reflects the continued high incidence of trichinosis in Spain. In fact, trichinosis rates in Spain are comparable to those which have not been encountered in the United States for more than 50 years [1,2] – see graph.

Cross-border incidents of trichinosis are relatively uncommon. The following chronology, including cases related to importation or human travel, is abstracted from Gideon (primary references available on request)

1975 – An outbreak (125 cases) of trichinosis in France was traced to horse meat imported from Poland.
1976 (publication year) – An outbreak (6 cases) in Paris was associated with travel to Egypt.
1985 – Outbreaks (1,073 cases, 2 fatal) in France were caused by horse meat imported from Germany and the United States.
1986 (publication year) – An outbreak (20 cases) among Gurkha soldiers serving in Hong Kong was associated with a barbecue.
1986 – An outbreak (2 cases) was reported among French-Vietnamese nationals who had eaten pork sausages at a diplomatic reception in Laos.
1990 – An outbreak (90 cases) among Southeast Asian refugees in the United States and Canada was associated with uncooked commercial pork served at a wedding in Des Moines, Iowa. This was the fourth outbreak reported since 1975 among Southeast Asian refugees in North America.
1992 – The world’s first case of human infection by Trichinella pseudospiralis was reported in New Zealand – probably acquired in Tasmania, Australia.
1982 – An outbreak (1,000 cases or more) was reported in the southern region of Lebanon – including six cases hospitalized in Israel.
1993 – An outbreak (538 cases) in France was traced to the meat of a single horse imported from Canada.
1994 – An outbreak (7 cases) in France was associated with horsemeat imported from Mexico.
1995 (publication year) – An outbreak (8 cases) in Germany and the former Yugoslavia involved family members who had shared smoked ham.
1995 to 1996 – A single case of trichinosis was reported in Japan – acquired during travel to Poland.
1997 – A Japanese traveler acquired trichinosis from smoked bear meat while in China.
1998 – An outbreak (404 cases, 37 hospitalized) in the France was related to consumption of meat from horse which had been imported from Yugoslavia.
1998 – An outbreak (92 cases, 0 fatal) in Italy was ascribed to imported Polish horsemeat.
1998 to 1999 – An outbreak (44 cases) in Germany was ascribed to raw smoked sausage (mettwurst) imported from Spain.
1999 – An outbreak (8 cases) among Yugoslavian immigrants in the United Kingdom was ascribed to salami imported from Serbia.
2000 (publication year) – An outbreak (25 cases) was reported among travelers returning to Singapore from a neighboring country.
2000 – An outbreak (8 cases) in England and Wales was ascribed to ingestion of imported meat products.
2001 – An outbreak (7 cases, none fatal) among Eastern European immigrants living in Rome was ascribed to imported pork sausage.
2002 – An outbreak (3 cases) in Germany was caused by infested smoked wild boar meat imported by travelers from Romania.
2002 – An outbreak (30 cases, 0 fatal) was reported among Thai workers in the Israel who had ingested the meat of a wild pig.
2003 (publication year) – An outbreak in Germany was reported among members of a family from Bosnia.
2003 (publication year) – A Japanese national acquired trichinosis in Kenya.
2004 – An expatriate developed Trichinella britovi infection in France from barbecued leg of jackal (Canis aureus) eaten in Algeria.
2004 – Two of the three cases of Trichinosis reported in the Czech Republic had been acquired in Poland and Macedonia.
2004 – An expatriate from New Zealand acquired trichinosis in Laos.
2004 – An outbreak (7 cases) of trichinellosis was reported Danes who had eaten home-made sausage purchased in Romania.
2004 (publication year) – An outbreak (2 cases) was reported in the Netherlands among family members who has consumed infested pork in Montenegro.
2005 – An outbreak (9 cases) of Trichinella nativa infection among French hunters in Canada was caused by contaminated bear meat. Eight additional cases were reported among persons in France who shared imported meat.
2006 – An outbreak (49 cases) in China was related to meat imported from Laos.
2007 – An outbreak (214 cases) in Poland was ascribed to contaminated raw sausage. Five cases in Germany, two in Ireland and 1 in Denmark were related to travel in the area of the outbreak.
2007 – An outbreak (21 cases) of Trichinella britovi infection among persons in Spain and Sweden was related to Spanish wild boar sausage.
2007 – An outbreak (3 cases) in Germany was caused by contaminated cured sausage eaten in Romania.
2008 – An outbreak (4 cases, 0 fatal) of trichinosis in Italy was reported among persons who had ingested infested pork in Romania.
2008 – An outbreak (8 cases) of human trichinosis associated with ingestion of raw soft-shelled turtles (Pelodiscus sinensis) was reported in Taiwan, including two cases exported to Japan. The pathogen in this case may have been Trichinella papuae.
2009 – An outbreak (3 cases) of trichinosis was reported among French nationals who had ingested warthog ham in Senegal.
2009 – An outbreak (5 cases) was reported among French tourists who ingested the meat of a grizzly bear while on a boating trip in Canada.
2009 – An outbreak of trichinosis among boar hunters in Bosnia was associated with a case hospitalized in Switzerland.
2010 – A case in Scotland was ascribed to ingestion of meat imported from France.
2011 (publication year) – A Thai worker acquired Trichinella papuae trichinosis from wild boar meat in Malaysia.

1. Berger SA. Infectious Diseases of Spain, 2014. 623 pages, 194 graphs, 3,844 references. Gideon e-books.
2. Berger SA. Trichinosis: Global Status, 2014. 90 pages, 73 graphs, 894 references. Gideon e-books.

Diagnosis Support for Ebola through GIDEON

The Diagnosis module of Gideon is designed to generate a ranked differential diagnosis list for any Infectious Diseases scenario. In recent weeks, we’ve been running simulations of Ebola. The following link will access a Power Point “show” demonstrating one such scenario. Ebola case (Powerpoint)

Ebola Deaths in Perspective

Recent events in West Africa have largely eclipsed several other ongoing outbreaks on the global stage. For example, over 780,000 cases of Chikungunya have been reported in the western hemisphere in recent months, including 1,371 cases in the United States (vs. only 4 of Ebola). Obviously, the severity of Ebola far outweighs that of Chikungunya; thus, the ratio of reported Chikungunya cases to Ebola cases (772,069 / 10,141) is 76-to-1, the ratio of Ebola deaths to Chikungunya deaths (4,922 / 118) is 73-to-1.

Sadly, one ongoing epidemic which is more severe than Ebola in both disease numbers and mortality, receives little notice from the lay media. The last available publication on cholera in Haiti reported 780,541 cases (8,562 fatal) as compared to 10,041 (4,922 fatal) of Ebola. As of October 28, cases of both diseases had been reported in nine additional countries.

The following graph illustrates mortality figures for some ongoing Infectious Disease outbreaks (I’ve added SARS for historic impact). The lower row records the number of countries which reported cases originating in the outbreak epicenter.

Outbreak Deaths

Chikungunya – Coming to America ?

Chikungunya and Zika: Global Status

Chikunguna is hardly a “household” word in the United States; but we may all be talking about the disease very soon! This viral infection, transmitted by mosquitoes, is associated with high fever, rash and severe joint pains. Even after recovery, the pains may persist for many months. Originally described in Africa, the disease spread to Asia, causing an epidemic of over 1.5 million cases in India during 2006 to 2007. At one point, an Indian traveler carried the infection to Italy, resulting in hundreds of cases in the region of Ravenna.

During the first half of 2014, new outbreaks were reported in the South Pacific; and in a period of only five months, over 660,000 cases have occurred in the Caribbean, involving essentially all regional islands and several mainland countriues. Once a “rare tropical disease”, Chikungunya is now endemic to at least 75 countries. Few realize that the mosquitoes which transmit Chikungunya in Africa, India, Italy and the Caribbean are also found in Florida and Texas. 750 imported cases have already been reported on the U.S. mainland during 2014, and it may be only a matter of time until a mosquito bites one such case, and begins a chain of transmission to the local population (as occurred in Italy in 2007).

Chikungunya and Zika – Global Status, 2014 is the most up-to-date book on the subject of Chikungunya. (The volume also covers Zika, another emerging mosquito virus disease). The book presents a thorough review of global and country-specific epidemiology, as well as complete background information on the history and clinical features of Chikungunya, including 22 graphs and 1,626 linked references. The next updated version will be released in early 2015. Further specs are available at

Ebola – The Book

Ebola: Global StatusA disease which was relatively unknown to most people – and even most health care professionals – has suddenly become a household word throughout the world. As of September 2014, over 2,000 people have died in the largest recorded outbreak of Ebola. Ebola: Global Status, 2014, the most up-to-date book written on the disease, examines the history, clinical features and epidemiology of Ebola virus infection. A country-by-country chronology presents all aspects of Ebola, including a relatively obscure outbreak which occurred among monkeys in the Philippines, and later spread to Texas.

For further specs on Ebola: Global Status, 2014, see The next yearly update of the book will be released in early 2015.

Correction: The original text inadvertently stated that this was the only book on the subject. This has been re-edited to state that this is “the most up-to-date book written on the disease.”

Campylobacteriosis in Iceland

A recent posting in ProMED belies the fact that Iceland reports the lowest rates of campylobacteriosis in that region of Europe. [1-2] See graph [3] Note that an earlier outbreak (436 cases) was reported in 1999.


1. Berger SA. Infectious Diseases of Iceland, 2014 371 pages, 75 graphs, 1,455 references. Gideon e-books,
2. Berger SA. Campylobacteriosis: Global Status, 2014 104 pages, 96 graphs, 1,073 references. Gideon e-books,
3. Gideon graph tool at