Free 5 Day Trial Latest Updates Video Tutorials
Subscribe , x j

Archive for the ‘Epidemiology’ Category

Coccidioidomycosis in the United States

Although largely limited to the western and southwestern states, Coccidioidomycosis is more commonly reported than legionellosis. More Americans die from Coccidioidomycosis than from the other two regional mycoses, Blastomycosis and Histoplasmosis. [1,2]


While Coccidioidomycosis is best known as a disease of California (“Valley Fever”) , highest incidence is reported from Arizona.  These data are even more striking when adjusted for relative population size (cases per 100,000 population).



  1. Berger S. Infectious Diseases of the United States, 2019. 1,422 pages , 513 graphs , 18,048 references.  Gideon e-books,
  2. Gideon e-Gideon multi-graph tool,

India: Diphtheria, Pertussis and Tetanus

Although global incidences of Diphtheria, Pertussis and Tetanus declined dramatically during the second half of the twentieth century, relatively high rates for these diseases continue to be reported from India.  India accounted for 17.7% of the total World’s population in 2018, but reported 46% of global Tetanus, 53% of global Diphtheria (and only 10.2% of global Pertussis) that year.  Similarly, 68% of the population of Southeast Asia (SEA) live in India, while that country accounted for 85% of Diphtheria, 75% of Pertussis and 90% of tetanus for SEA in 2018. [1-4]   Trends for these data are charted in the following three graphs. [5]


  1. Berger S. Infectious Diseases of India, 2019. 620 pages , 109 graphs , 6,807 references. Gideon e-books,
  2. Berger S. Diphtheria: Global Status, 2019. 389 pages , 451 graphs , 699 references. Gideon e-books,
  3. Berger S. Tetanus: Global Status, 2019. 561 pages , 816 graphs , 390 references. Gideon e-books,
  4. Berger S. Pertussis: Global Status, 2019. 417 pages , 514 graphs , 1,028 references. Gideon e-books,
  5. Gideon e-Gideon multi-graph tool,

Campylobacteriosis in Scandinavia

For more than twenty years, rates of campylobacteriosis in Scandinavia have been 50% above those of Europe as a whole. [1]. During 1995 to 2000, approximately 20-to-60 cases per 100,000 were reported in Denmark, Finland, Norway and Sweden; increasing to 60-to-100 cases per 100,000 during 2010 to 2018. [2]  Similar regional trends have been reported for EHEC (enterohemorrhagic E. coli) infection; while rates of yersiniosis have been decreasing.

Sweden = Laboratory reports     other countries = Cases


1. Berger S. Campylobacteriosis: Global Status, 2019. 157 pages , 102 graphs , 1,584 references. Gideon e-books,
2. Gideon e-Gideon multi-graph tool,

Note featured on ProMED



Venereal Diseases in Europe

As of 2017, the reported incidence of syphilis in the European Union is higher that that of HIV infection.   In the following chart, I’ve contrasted trends of venereal diseases for the region. [1]  Data are derived from GIDEON and the Gideon e-book series. [2]  Note that gonorrhea is most common, followed by syphilis, HIV / AIDS and lymphogranuloma venereum (LGV).  In fact, if current trends continue, LGV infection may become more common than AIDS in the near future.  As depicted in the second chart,  reported cases of chlamydial infection are higher than the combined total for all other venereal diseases, and continue to be rise at an alarming rate.

1. Gideon e-Gideon multi-graph tool,

2. Berger S. Infectious Diseases of the World, 2019. 1,750 pages , 456 graphs , 42,302 references. Gideon e-book series,

Japanese Encephalitis in India

Outbreaks in Japanese encephalitis (JE) / Acute encephalitis syndrome (AES) have been reported from Assam and Uttar Pradesh in recent weeks.  Since 2008, official reports from India do distinguish between these two entities.  The following chart [1] indicates that although India has experienced increasing rates for both JE and AES on a national level,  incidence has not increased in these two states. [2,3]


1. Gideon e-Gideon multi-graph tool,
2. Berger S. Infectious Diseases of India, 2019. 620 pages , 109 graphs , 6,807 references. Gideon e-books,
3. Berger S. Japanese Encephalitis: Global Status, 2019. 100 pages , 66 graphs , 1,208 references.  Gideon e-books,

Histoplasmosis in Travelers

In 2019, several Canadian tourists acquired histoplasmosis while exploring caves in Cuba.  The Gideon database maintains an ongoing record of all cross-border Infectious Diseases events, including importation of animals and foods associated with zoonotic disease. [1-3]

As of 2019, 76 episodes of histoplasmosis had been associated with travel, involving at least 574 individual cases (8 fatal).  18 of these events were related to cave exposure, including two involving caves in Cuba.  Four publications described acquisition of histoplasmosis by Canadian travelers – two involving cave exposure.

In the following screen-shot, the frame to the left displays an interactive chronicle of cross-border histoplasmosis.  Users can sort data by year of event, country of exposure / origin, etc.  In this example I’ve selected “Setting” in order to study cases related to “cave exposure.”  Additional details and electronically-linked references appear when the user clicks on “Show event notes”


  1. Gideon Online.
  2. Berger S. Histoplasmosis: Global Status, 2019. Gideon e-books,
  3. Berger S. GIDEON Guide to Cross Border Infections, 2019. 256 pages, 134 tables, 4,543 references.

Note featured on ProMED

Bolivian Hemorrhagic Fever

In 2019, a small outbreak of Bolivian hemorrhagic fever was reported at a hospital in La Paz, Bolivia.  The following background data on Bolivian hemorrhagic fever are abstracted from Gideon and the Gideon e-book series. [1,2]  Primary references are available from the author.

Bolivian hemorrhagic fever (BHF) is caused by Machupo virus (Arenaviridae, Tacaribe complex, Mammarenavirus).  The disease was initially described in 1959 as a sporadic hemorrhagic illness in rural areas of Beni department, eastern Bolivia; and the virus itself was first identified in 1963.  BHF is most common during April to July in the upper savanna region of Beni.  Principal exposure occurs through rodents (Calomys callosus) which enter homes in endemic areas.

BHF is one of several human Arenaviruses diseases reported in the Americas: Argentine hemorrhagic fever (Junin virus), Brazilian hemorrhagic fever (Sabia virus), Lymphocytic choriomeningitis, Venezuelan hemorrhagic fever (Guanarito virus) and Whitewater Arroyo virus infection.  (At least two related diseases are reported in Africa: Lassa fever and Lujo virus infection)

Infection of C. callosus results in asymptomatic viral shedding in saliva, urine, and feces; 50% of experimentally infected C. callosus are chronically viremic and shed virus in their bodily excretions or secretions.  C. callosus acquires the virus after birth, and start shedding it through their urine and saliva while suckling.  When mice acquire the virus as adults, they may develop immunity and no longer shed the virus.

Although the infectious dose of Machupo virus in humans is unknown, exposed persons may become infected by inhaling virus in aerosolized secretions or excretions of infected rodents, ingestion of food contaminated with rodent excreta, or by direct contact of excreta with abraded skin or oropharyngeal mucous membranes. Nosocomial and human-to-human spread have been documented.  Hospital contact with a patient has resulted in person-to-person spread of Machupo virus to nursing and pathology laboratory staff.

In 1994, fatal secondary infection of six family members in Magdalena, Bolivia from a single naturally acquired infection further suggested the potential for person-to-person transmission.

During December 2003 to January 2004, a small focus of hemorrhagic fever was reported in the area of Cochabamba. A second Arenavirus, Chapare virus, was recovered from one patient with fatal infection.

Early clinical manifestations consist of nonspecific signs and symptoms including fever, headache, fatigue, myalgia, and arthralgia.  Within seven days patients may develop hemorrhagic signs, including bleeding from the oral and nasal mucosa and from the bronchopulmonary, gastrointestinal, and genitourinary tracts. Case fatality rates range from 5% to 30%.

Ribavirin has been used successfully in several cases of BHF.  The recommended adult regimen is: 2.0 g IV, followed by 1.0 g IV Q6h X 4 days, and then 0.5 g Q8h X 6 days

Note that the etiologic agent and clinical features of BHF are similar to those of Argentine hemorrhagic fever (AHF).  Neurological signs are more common in AHF, while hemorrhagic diatheses are more common in BHF.  A vaccine available for AHF could theoretically be effective against BHF as well.


  1. Berger S. American Hemorrhagic Fevers: Global Status, 2019. Gideon e-books,
  2. Berger S. Infectious Diseases of Bolivia, 2019. 342 pages, 87 graphs, 495 references.

Note featured on ProMED


Diphtheria in Thailand

Although two fatal cases of diphtheria were recently reported in Thailand [1], rates of this disease have declined dramatically since the 1970’s.  In fact, Thailand can serve as an icon for the effectiveness of vaccination.  In the following graph, I’ve contrasted rates of diphtheria, pertussis and tetanus with WHO estimates of DPT vaccine uptake.  The second graph depicts the effect of DPT vaccination on diphtheria mortality in this country. [2,3]


  2. Berger S. Infectious Diseases of Thailand, 2019. 506 pages , 169 graphs , 2,339 references. Gideon e-books,
  3. Gideon e-Gideon multi-graph tool,

Note featured on ProMED

Measles: Correlation of Vaccine Uptake with Disease Rates

The following is a country-by-country analysis of measles reporting trends vs. vaccine uptake.  For purposes of consistency, incidence data and population statistics used to calculate rates per 100,000 will be limited to those published by the World Health Organization (WHO).  Resultant graphs were generated by Gideon and abstracted from the Gideon e-book series [1,2]  True estimates of vaccination update statistics are those published by WHO, in most cases available only since 1980.  Data published by the countries themselves were not used, to avoid possible bias or inconsistency when comparing data among countries. Historical disease data which precede 1980 have also been appended to graphs to further appreciate the impact of vaccination.

The reader will note that in virtually all cases, the presumed impact of vaccine uptake on disease incidence occurs when vaccine uptake exceeds 80%, and again when rates increase beyond 90%.   As such, the few countries which have not achieved 80% uptake, or have consistently reported >90% uptake since 1980 are excluded.  Graphs are not included for countries for which data are not reported, or reported only sporadically.

Individual graphs for 135 countries are presented below in alphabetical order.  In 127 (94%) of these, a clear relationship seems to exist between increasing vaccine uptake and decreasing rates of measles.  In eight cases, temporary “spikes” in disease incidence were reported during years of high vaccine uptake: Japan, Jordan, Republic of Korea, Seychelles, Solomon Islands, South Africa, Sri Lanka and Syria.

I have not attempted to perform a statistical analysis of this phenomenon, and cannot say with certainty that a confounding (third) factor does not exist.  Nevertheless, these graphs appear to indicate a favorable effect of vaccination on measles incidence.

Measles Vaccine Uptake vs. Disease rates (per 100,000)


  1. Gideon e-Gideon multi-graph tool,
  2. Berger S. Measles: Global Status, 2019. 548 pages , 538 graphs , 5,779 references. Gideon e-books,

Measles Vaccine Effectiveness – Supportive Data

Where data are available, reported rates of measles are inversely related to vaccination coverage.  This observation is true for virtually every country … from Algeria to Zambia  – and are most evident as percentage vaccine coverage exceeds 80 percent.  The following charts are based on WHO statistics for measles incidence and estimates (rather than individual reports) of true vaccine coverage.  Note in the following charts, that when groups of countries are compared, the disease rates themselves are often numerically lower for countries which have attained highest vaccination coverage [1,2]  For  example,  in the third chart, the relatively low vaccine coverage for Africa is reflected in a relatively high disease rate for that region.  The two lower charts depict a decrease in fatal measles cases which have paralleled increasing vaccine coverage.



  1. Gideon e-Gideon multi-graph tool,
  2. Berger S. Measles: Global Status, 2019. 548 pages , 538 graphs , 5,779 references. Gideon e-books,

Note features in ProMED