Time and Place:
Most outbreaks of leptospirosis are reported in coastal regions: Gujarat, Mumbai, Kerala, Chennai and the Andaman Islands.
- High rates have been reported from Valsad district (Gujurat) for several years.
- Outbreaks of ‘Andaman hemorrhagic fever’ were first reported in 1988, and identified as leptospirosis in 1993.
- Highest rates occur during October to November.

Prevalence surveys:
22.57% of FUO in Guwahti, Assam (2008 publication)
3.2% of febrile patients and 7.0% of febrile patients with jaundice in Delhi (1966). 32 cases were confirmed in the region during 2000 to 2001.
23.81% of patients hospitalized for febrile jaundice in Kolkata.

Seroprevalence surveys:
(more…)

Recently, a British woman died of leptospirosis acquired from the scratch of a rodent. Few people realize that leptospirosis is not uncommon in the United Kingdom. In fact, 18 fatal cases were reported in England and Wales during 1988 to 2006. In the following graph, I’ve contrasted disease rates for the region with those of the United States.

Update: Also quoted in ProMED

A recent outbreak highlights the fact that New Caledonia has one of the highest rates of leptospirosis in the Pacific region (see graph). In fact, in these islands, Leptospirosis is more common than Salmonellosis, Hepatitis A, Hepatitis B, Gonorrhea and Tuberculosis (see graph).

The following background information regarding Leptospirosis in New Caledonia is abstracted from GIDEON:

Leptospirosis is most common in west coast cattle-farming areas and rural Melanesian settings

• Disease rates are highest in the Bourail area.
• Disease rates peak during March to May.

Notes:

1. An average of 4 fatal cases are reported yearly.
2. 57 cases were diagnosed during 1983 to 1985.
3. 239 cases were reported during 2001 to 2005. The principal serogroups were Icterohaemorrhagiae (69%), Australis (8%), Pyrogenes (6%)

58% of cattle are seropositive.

The principal reservoirs in this country are rodents, pigs, horses and cattle.

The principal species are Leptospira serovars. Icterohaemorrhagiae, tarassovi, pyrogenes, canicola, australis and pomona.

• Serovar tarassovi accounts for 22% of cases, icterohaemorrhagiae 18% and pyrogenes 17%.

Notable outbreaks:
1989 – An outbreak (144 cases, 6 fatal) was reported, with 41% of the cases caused by serovar icterohaemorrhagiae.

Update: Also mentioned in ProMED