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Archive for the ‘Epidemiology’ Category

Ross River Virus in Queensland

Queensland accounts for approximately 50% of Ross River virus infections reported in Australia. Notwithstanding an increase in incidence during January to February 2015, rates in Queensland have remained fairly constant for over two decades. [1,2] See graph


1. Berger S. Infectious Diseases of Australia, 2015. 616 pages, 165 graphs, 3,941 references. Gideon e-books,
2. Berger S. Australo-Pacific Arboviruses: Global Status, 2015.

Note featured on ProMED

Melioidosis in the United States

The following background data are abstracted from Gideon and the Gideon e-book series [1,2] (primary references available on request)

The first case of melioidosis in the Western hemisphere was diagnosed in the United States in 1945 – an American who had worked in the Panama Canal Zone during 1927 to 1928.

Sporadic autochthonous cases (five reports to 2013) have been reported from Arizona, Georgia, Hawaii, Oklahoma, Ohio and California. The fifth case of autochthonous melioidosis was reported in Ohio in 2013. Imported cases have originated from Laos, Mexico, Viet Nam and Thailand. Two cases imported from Honduras were reported in Florida in 2005; and an American girl acquired the disease in Aruba in 2011 (publication year).

A case of pneumonia and septicemia caused by Burkholderia thailandensis has been reported in the United States.

It has been estimated that 225,000 seropositive Army personnel returned from Viet Nam, and may still be at risk for reactivation. 81 individual case reports (14 fatal cases) of melioidosis acquired in Vietnam were published during 1965 to 1969. In one case, a Vietnam veteran developed melioidosis 29 years after returning to the United States. In another instance, a veteran developed the disease 63 years following return from the Pacific region. Venereal transmission was reported from a Vietnam veteran to his wife in the United States. 38% of American Marines acquired seropositivity toward melioidosis following a two-week stay in Thailand (2006).

Animal infection:
1969 – Five cases of melioidosis in three separate outbreaks were diagnosed among imported nonhuman primates – two stump-tailed macaque monkeys (Macaca arctoides), a chimpanzee (Pan troglodytes), a pig-tailed monkey (Macaca nemestrina) and a rhesus monkey (Macaca mulatta).
2007 (publication year) Burkholderia pseudomallei was isolated from two pet green iguanas (Iguana iguana) in California
2013 (publication year) – A pigtail macaque (Macaca nemistrina) imported from Indonesia into the United States was found to have melioidosis.

1. Berger SA. Melioidosis and Glanders: Global Status, 2015. 51 pages, 10 graphs, 754 references. Gideon e-books,
2. Berger SA. Infectious Diseases of the United States, 2015. 1,208 pages, 483 graphs, 13,730 references. Gideon e-books,

Note posted on ProMED

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.

Measles: Still A Problem Despite Four Decades of Progress

Although measles rates have declined dramatically during the past four decades, a recent upsurge reflects sub-optimal enforcement of vaccination in many countries. In the following graphs, I’ve summarized reported measles incidence and estimated vaccine uptake by region. Note that vaccination rates remain below 80% in three W.H.O. regions (African, Eastern Mediterranean and Southeast Asian), while they exceed 90% in the other three (European, American and Western Pacific) [1.2]


1. Berger S. Measles: Global Status, 2014. 415 pages, 537 graphs, 3,376 references. Gideon e-books,
2. Berger S. Infectious Diseases of the World, 2014. 1333 pages, 397 graphs, 26,187 references. Gideon e-books,

Also quoted in ProMED

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