Recent reports of Japanese encephalitis (JE) activity belie the fact that disease rates in Vietnam have decreased in recent years. [1,2]

Time and Place:
- Japanese encephalitis was first reported in Vietnam in 1960.
- Most cases of Japanese encephalitis in Vietnam occur in the South during the rainy and early dry season; and in the north during late summer and autumn.
- 61,729,000 persons (73% of the population) live in areas of risk.

Vaccine Schedule:
BCG – birth
DTwP – 2, 3, 4 months
HepB – birth; 2, 4 months; [since 2003]
Japanese encephalitis – 12, 13, 25 months; Part of country [selected HRD]
Measles (monovalent) – 9 months
OPV – 2, 3, 4 months
TT – pregnant women; CBAW (15-35) in some areas
Typhoid – 3-10 years; Part of country [selected HRD]
Vitamin A – 6-11, 12-17, 18-24, 31-36 months

WHO estimates for vaccine coverage decreased slightly from 95% in 2006, to 88% in 2008 (see graph).

The incidence of Japanese encephalitis has decreased dramatically during the past three decades – from a peak of 4,935 cases in 1985, to only 558 cases in 2000.
– 9,574 cases were reported during 1986 to 1990; 6,981 during 1991 to 1996.
– 68 cases were officially reported in 2009.
– Annual mortality from the disease has varied from 60 to 150 cases.

Incidence and Prevalence:
- Japanese encephalitis accounted for 67% of acute childhood encephalitis in Hanoi during the summer of 1995.
- The annual incidence among children in Southern Vietnam is 4.6% (2007 publication)
- A recent outbreak was centered in Ha Bac and Hai Hung.
- Eight children died of presumed Japanese encephalitis in Kien Giang Province in 1999.
- 200 cases were reported in the northern region during May to June, 2005.

Exported cases
- An Australian soldier acquired Japanese encephalitis in Vietnam (reported in 1975).
- In 2006, an Italian traveler developed Japanese encephalitis (nonfatal) after returning from Vietnam.
- In 2008, an American tourist contracted Japanese encephalitis (nonfatal) while in Vietnam and Cambodia.

Related diseases:
- A new arbovirus, tentatively named “Nam Dinh virus,” was implicated in several cases of encephalitis in Ha Noi and Ha Tay in 2003, and in Bac Giang Province in 2004.

References:
1. Berger SA. Infectious Diseases of Vietnam, 2010, 382 pp. Gideon e-book series, http://www.gideononline.com/ebooks/country/infectious-diseases-of-vietnam/
2. Berger SA. Japanese Encephalitis: Global Status, 2010, 51 pp. Gideon e-book series, http://www.gideononline.com/ebooks/disease/japanese-encephalitis-global-status/

Update: Posted in ProMED

In October, 2008 an American tourist in Tanzania acquired trypanosomiasis. At least 40 such cases have been reported since 1970. The following chronology is abstracted from Gideon. Note that the country of disease acquisition was reported in 37 cases – of which Tanzania accounted for 18 and Malawi 11.

Year:
1970 – A case of trypanosomiasis was reported in Switzerland.
1970 – Two American tourists acquired trypanosomiasis while in Kenya and Rwanda.
1975 – A Swedish tourist acquired trypanosomiasis in Gambia.
1977 – A case of trypanosomiasis was reported in Switzerland.
1981 – An American acquired trypanosomiasis in Tanzania.
1990 (publication year) – Two Swiss nationals acquired trypanosomiasis in Rwanda.
1997 – A Brazilian acquired trypanosomiasis in Angola.
1998 – An Australian acquired trypanosomiasis in Tanzania.
2000 – One American and one British national acquired trypanosomiasis in Tanzania.
2001 – Eleven persons acquired trypanosomiasis in Tanzania: three Dutch, two Italians, and one each Swedish, Norwegian, Belgian, South African, American and British.
2001 – A British national acquired trypanosomiasis in Zambia.
2004 – Two British brothers acquired trypanosomiasis in Tanzania.
2004 – Two Italians acquired trypanosomiasis, in Gabon and Central African Republic.
2005 – An American acquired trypanosomiasis in Tanzania.
2005 – Two South Africans acquired trypanosomiasis in Malawi.
2007 – A British national, 5 South Africans, 1 Canadian and two Australians acquired trypanosomiasis in Malawi.

A recent outbreak of suspected salmonellosis among British travelers at a hotel in Italy highlights the risk for such infections among tourists, expatriates and similar groups in transit through foreign countries. The following chronology of similar episodes is abstracted from GIDEON:

1976 – An outbreak (550 cases) of Salmonella typhimurium infection affecting 4 international air flights (Las Palmas-Helsinki, Las Palmas-Honover) was caused by contaminated mayonnaise prepared in Spain.
1985 – An outbreak (168 cases) of Salmonella minnesota infection was reported at a Filipino workers’ camp in Saudi Arabia. (more…)