Archive for the ‘Epidemiology’ Category

Dengue in Egypt

Monday, June 7th, 2010

The following backround data on dengue in Egypt are abstracted from the GIDEON e-book series. [1,2]

Historical background:
– Outbreaks of dengue were reported in Cairo and Alexandria during 1799; and in Port Said in 1871.
– Subsequent cases were reported in Cairo and the sea ports in 1880; and in the Nile delta in 1889.
– Dengue fever was widespread during the first half of the 20th century.
– A decline in transmission was recorded in Egypt after 1940, and was ascribed to rapid decrease of Stegomyia (Aedes) aegypti populations with the introduction of DDT during and after the Second World War.

Notable outbreaks:
1928 – An outbreak (70 fatal cases) was reported.
1937 – An outbreak (50 fatal cases) was reported.

References:
1. Berger SA. Infectious Diseases of Egypt. 2010, Gideon Informatics, Inc., 367 pp. http://www.gideononline.com/ebooks/country/infectious-diseases-of-egypt/
2. Berger SA. Dengue: Global Status. 2010, Gideon Informatics, Inc., 191 pp. http://www.gideononline.com/ebooks/disease/dengue-global-status/

Eosinophilic Meningitis in Australia

Sunday, May 16th, 2010

Recently, a man in New South Wales acquired eosinophilic meningitis (angiostrongyliasis) after ingesting a slug.

The 1st Australian case of human angiostrongyliasis was reported in 1971, in Brisbane.

At first, sporadic cases were reported only from coastal Queensland, northern New South Wales.

Four cases were reported in Victoria to 1999 (3 of these imported from Fiji; one fatal case).

Seropositivity is common among aboriginals.

Reservoirs:
The parasite has been identified in dogs in Sydney as well as in grey-headed fruit bats (Pteropus poliocephalus) Bennett’s wallaby (Macropus rufogriseus) rufous bettongs (Aepyprymnus rufescens) and captive tamarins (Sanguinus spp).

Further information regarding this, and all other diseases endemic to Australia, is available in Infectious Diseases of Australia. Los Angeles, Gideon Informatics, 2010. 488 pp. [edited] www.gideononline.com/ebooks/country/infectious-diseases-of-australia/

Update: Published in ProMED

Kunjin Virus

Wednesday, April 14th, 2010

Kunjin virus (KUN) is similar Murray Valley encephalitis (MVE) virus; however, infection by KUN is generally milder than that with MVE, with a lower rate of encephalitis. KUN appears to have been responsible for some of the ‘Murray Valley encephalitis’ cases reported in 1974, and was implicated in an additional sporadic case in northern Victoria in 1984. KUN-is more widely distributed than MVE, and is found in most of tropical Australia, eastern Queensland, and occasionally southeastern Australia.

Notes for individual years:
1996 – Two cases in Queensland.
1997 – Two cases in Western Australia and two in Northern Territory. A presumptive case of KUN was reported in Pilbara, WA
2000 – Three in Western Australia and one in Northern Territory.
2001 – New South Wales, Northern Territory [2 cases] and Western Australia.
2003 – All cases reported from Queensland
2004 – 11 in Queensland and 1 in Victoria.
2005 – 1 in Queensland
2006 – 2 in Western Australia and 1 in Queensland

The vectors for KUN are Culex annulirostris, Cu. pseudovishnui and Cu. squamosis.

An extensive review of Australo-Pacific Arbovirus diseases is available in the ebook Australo-Pacific Arboviruses: Global Status

Update: posted in ProMED

Leptospirosis in Argentina

Sunday, April 4th, 2010

Leptospirosis was first identified in Argentina in 1915.
- Most cases are reported from Greater Buenos Aires.
- 276 cases were diagnosed in the Greater Buenos Aires area during 1990 to 1999 – 43 of these characterized by pneumonia.
- 32 cases (6 fatal) were reported in Santa Fe during the first two months of 2010.

The following graphs depict incidence and case rates of Leptospirosis in Argentina, and contrast these data with those of surrounding countries:


Notes:
Individual years:
1998 – Included 53 cases in Santa Fe and 16 in Buenos Aires.
2001 – Included 63 cases in Santa Fe and 89 in Buenos Aires.
2005 – Three fatal.

Twelve serovars were identified in human infection during the 1970′s, with most cases due to serovars bratislava, icterohaemorrhagiae and butembo.
- 41% of infections during 1984 to 1994 were due to Leptospira interrogans canicola.

Seroprevalence surveys:
15.7% of the population, nationwide (1976 publication)
8.7% of healthy persons in Corrientes and 0.5% in Neuquen are seropositive (1979 publication)

Reservoirs:
The principal hosts in this country are rats, pigs and dogs.
- 25% to 40% of rats and 10% to 60% of dogs in Buenos Aires are seropositive – most often toward L. interrogans canicola and L. i. pyrogenes.
- Antibody toward serovars pomona, hebdomadis group, pyrogenes, tarassovi, and canicola has been demonstrated in healthy horses.

Notable outbreaks:
1976 – An outbreak (10 cases) in Buenos Aires followed swimming in a drainage canal contaminated by pigs.
1977 (publication year) – An outbreak was reported among children in Longchamps, Buenos Aires Province.
1998 – An outbreak (12 confirmed and 2 suspicious cases) in Santa Fe was related to water.
2004 – An outbreak (12 suspect cases, 1 fatal) was reported in Entre Rios.
2007 – An outbreak (400 cases or more) was reported in Santa Fe.

Vaccination Coverage in Haiti

Sunday, March 7th, 2010

Although vaccination coverage for major infectious diseases in Haiti was below that of other countries in the region, recent WHO estimates had shown some improvement in recent years. Most recent data are summarized in the following chart:

Also check out GIDEON’s free ebook: Infectious Diseases of Haiti

Leptospirosis in Queensland

Friday, February 19th, 2010

A recent ProMED warning to backpackers is well taken – leptospirosis is a common disease in the Pacific region. In the following graphs I’ve compared disease rates for Australia and New Zealand with those of the United States.

Leptospirosis rates in nearby New Caledonia are even more striking, and exceed those of salmonellosis, hepatitis A, hepatitis B, gonorrhea, and tuberculosis.

Tuberculosis in Haiti

Sunday, February 7th, 2010

As pointed out by ProMED, tuberculosis rates in Haiti were already highest in the region before the current disaster. In the following graph, I’ve contrasted reports for Haiti with those of neighboring countries.

Don’t forget to check out GIDEON’s free e-book: Infectious Diseases of Haiti

E-book: Infectious Diseases of Haiti by GIDEON

Thursday, January 28th, 2010

When the humanitarian disaster in Haiti began to unfold, we accelerated development of a comprehensive book on the diseases of that country. This will be one in a series of ebooks which present the status of all infectious diseases…in all individual countries. This ebook, Infectious Diseases of Haiti, 2010 edition, will be offered free of charge to all health professionals concerned with the current disaster.

There are 347 forms of human infectious disease in the world today – and 198 of these (more than half) are known to occur in Haiti. Sadly, one of the “side effects” of living in a poor and disaster-ridden economy is a lack of useful facts regarding the local status of individual diseases. GIDEON (Global Infectious Diseases and Epidemiology Online Network) is a Web-based application which follows diseases – both on a global level and within each country. Data are updated daily and are derived from all relevant journals, websites, Health Ministry reports and publications of the World Health Organization. The electronic book (ebook) is generated from information in the GIDEON database, and will serve as the first comprehensive review of infectious diseases in Haiti. Similar ebooks are now available by country and disease.

Download the 2010 edition for free in PDF, ePub or mobi format, via the following links:
PDF: Infectious Diseases of Haiti by GIDEON (314 pages, 36 graphs, 3.4MB, updated May 5, 2010)
ePub: Infectious Diseases of Haiti by GIDEON (1.1MB, updated May 5, 2010)
mobi: Infectious Diseases of Haiti by GIDEON (1.8MB, updated July 23, 2010)

Or view the PDF ebook using Google.

Also available on Amazon Kindle for $1 in the US: Infectious Diseases of Haiti – Kindle version

Non-tuberculous Mycobacterial Infections

Wednesday, January 27th, 2010

Infection by non-tuberculous mycobacteria is commonly associated with cosmetic surgery, therapeutic injections and other invasive procedures. The following is a list of notable outbreaks:

Argentina:
2007 to 2007 – An outbreak (28 cases) of Mycobacterium immunogenum infection in Buenos Aires was associated with mesotherapy.

Brazil:
2002 to 2004 – An outbreak (14 cases) of mycobacterial wound infection associated with silicone breast implant surgery was reported in Campinas, Sao Paulo.
2003 – An outbreak (5 cases) in Sao Paulo of keratitis due to Mycobacterium immunogenum was associated with myopia surgery.
2004 to 2005 – An outbreak (311 cases) of Mycobacterium abscessus infections in Belem was associated with invasive procedures. Mycobacterium massiliense and M. bolletii were also identified in some cases.
2006 to 2007 – An outbreak (1,051 clinical cases) of Mycobacterium massiliense infections involving 63 hospitals in Rio de Janeiro state was related to contaminated instruments used in video-assisted surgery.
2008 – An outbreak (13 cases) of Mycobacterium fortuitum infections in Sao Paulo was associated with breast implant surgery.
(more…)

Pogosta Disease

Thursday, January 14th, 2010

Time and Place:
- Pogosta disease was first described in the Pogosta region of Northern Karelia in 1974.
- The disease is reported from all parts of Finland, however, North Karelia remains the region with highest incidence, with rates as high as 80 per 100,000.
- Extensive epidemics were recorded in 1974, 1981 (thousands of cases), 1988 and 1995.
- Incidence peaks during August to September.
- Disease incidence follows a seven-year cycle.
- Highest rates are reported in the age group 45 to 65.

Graph Notes:
1. 2,183 laboratory-confirmed cases were reported during 1981 to 1996 (average rate 2.7 per 100,000 per year).
Individual years:
1995 – Cases were distributed throughout the country, with highest incidence in central Finland, Savo and North Karelia.
2003 – Included 105 cases in Lansi-Suomi and 50 in Ita-Suomi.

Seroprevalence surveys:
1.7% of ‘suspected rubella’ in Finland (1973 to 1989)
11% of persons suspected of having viral infection – 17% in western Finland, 9% in northern and southern Finland
0.6% of women of childbearing age (1992)
5.2% of humans (Sindbis virus, 1999 to 2003)
27.4% of resident grouse (Tetrao urgallus, T. tetrix, Bonasa bonasia, Lagopus lagopus) in 2003, 1.4% in 2004

The principal vectors are mosquitoes (Culex and Culiseta species), and the presumed reservoirs are tetranoid and migratory birds.
- During an epidemic in 1981, 65% of black grouse and capercaillie were found to be seropositive.