Date: Wed 25 Sep 2019
Source: Food Safety News [edited]
<https://www.foodsafetynews.com/2019/09/swedish-officials-investigate-salmonella-outbreak/>

Authorities in Sweden are investigating a national outbreak of monophasic _Salmonella_ Typhimurium, which has affected almost 40 people.

Folkhalsomyndigheten (Public Health Agency of Sweden) reported that the source of the infections is still unknown. During September [2019], there was an increase in the number of cases of salmonellosis. The outbreak was identified, thanks to Folkhalsomyndigheten's microbial surveillance program. The latest date of illness onset is 6 Sep [2019].

To date, 36 illnesses from 10 counties have been linked by whole-genome sequencing. Most patients live in Vastra Gotaland, Jonkoping, Halland, and Dalarna. Those ill come from all age groups, including children and the elderly. More women, 22, than men, 14, have become ill.

Local authorities, Livsmedelsverket (Swedish Food Agency) and Folkhalsomyndigheten are investigating the outbreak to identify the source of infection that is suspected to be a food widely distributed in Sweden. People are being interviewed about what they ate the week before illness, with the aim of identifying common suspect foods.

The outbreak strain has multilocus variable-number tandem-repeat analysis (MLVA) pattern 3-12-11-N-211.

In 2018, isolates from 864 _Salmonella_ infections were typed; 91% were infected in Sweden, and 18% had been infected abroad. Among cases infected in Sweden, Enteritidis, Typhimurium, and monophasic Typhimurium were the most common serotypes.  [Byline: Joe Whitworth]
==========================
[The source of this outbreak is as yet unknown. By monophasic, it is meant that the organism does not have the complete set of flagellar serotypes. - ProMED Mod.LL]

[HealthMap/ProMED-mail map:
Sweden: <http://healthmap.org/promed/p/108>]
Date: Fri 6 Sep 2019
Source: Rikard Dryselius rikard.dryselius@folkhalsomyndigheten.se
[edited] [re: ProMED-mail Tularemia - Sweden (04): further increase, RFI
http://promedmail.org/post/20190905.6659382]
--------------------------------------------------------------------------------
According to clinical reports, a majority (over 70%) of the reported cases during the ongoing outbreak of tularemia in Sweden appear to have contracted the infection through insect bites, mainly mosquito bites. For about 1/4 of the disease cases no path of infection is indicated, while mainly animal contact and in some cases drinking water is indicated as route of infection for the remaining cases. -- Rikard Dryselius Folkhalsomyndigheten rikard.dryselius@folkhalsomyndigheten.se
=====================
[ProMED thanks Rikard Dryselius for this clinical information. - ProMED Mod.LL]
 
[HealthMap/ProMED-mail map of Sweden: <http://healthmap.org/promed/p/108>]
Date: Wed 28 Aug 2019
Source: Outbreak News Today [edited]
<http://outbreaknewstoday.com/tularemia-significant-rise-in-sweden-92551/>
-------------------------------------
As of [Mon 26 Aug 2019], about 560 human cases have been reported, much more this time of year than usual and even more than 2015 when 859 people across the country suffered from the illness. Most cases of illness are reported from central Sweden (the Dalarna region, Gavleborg and Orebro), but an increasing number of reports are also starting to come in from other regions, especially in northern Sweden.

Since the number of illness cases is usually highest in September in Sweden, the outbreak is expected to grow further in the coming weeks.

Infections in Sweden are mainly seen in forest and field hares and rodents, but the disease has been reported in several other species, including other mammals, birds, amphibians, insects, and ticks.

Tularemia, or harpest as it is known as in Sweden, is one of the most common native zoonoses in people in Sweden. People are infected mainly through mosquitoes, but also through direct contact with sick or dead animals and by inhalation of, for example, infectious dust.

The number of reported cases of harpest in humans varies from year to year, in recent years there have been reported between about 100 to over 800 cases per year. More than 90 percent of reported human cases have fallen ill in Sweden.
=========================
[This outbreak, primarily in central Sweden, continues to increase in size.  _Francisella tularensis_ subsp. _tularensis_ (type A) is associated with lagomorphs (rabbits and hares). Wild rodents are also frequently infected, and occurrence of human cases is usually linked to these host species. _F. tularensis_ is transmitted primarily by ticks and biting flies, and is highly virulent for humans and domestic rabbits.

Tularemia is largely confined to the Northern Hemisphere and is not normally found in the tropics or the Southern Hemisphere. _F. tularensis_ subspecies _holarctica_ naturally infects several mammalian wildlife species in northern Europe, in particular, mice, rabbits, hares, beavers, voles, lemmings, and muskrats. The ticks _Dermacentor reticularis_ and _Ixodes ricinus_ are vectors for the bacterium, although previous research has suggested that mosquito bites are the most frequent route of transmission to humans in Sweden.

In addition to vector transmission, tularemia may be spread via contact with infected animals or environmental fomites by inhalation, or by ingestion of the poorly cooked flesh of infected animals or contaminated water.

Tularemia can be transmitted by aerosol, direct contact, ingestion, or arthropods. Inhalation of aerosolized organisms (in the laboratory or as an airborne agent in an act of bioterrorism) can produce a pneumonic form. Direct contact with, or ingestion of, infected carcasses of wild animals (such as cottontail rabbit) can produce the ulceroglandular, oculoglandular, oropharyngeal (local lesion with regional lymphadenitis), or typhoidal form. Immersion in or ingestion of contaminated water can result in infection in aquatic animals. Ticks can maintain infection transstadially [pathogen remains with the vector from one life stage ("stadium") to the next] and transovarially [transmission of a pathogen from an organism (as a tick) to its offspring by infection of eggs in its ovary], making them efficient reservoirs and vectors.

The manifestations of infection in this growing outbreak in parts of Sweden are not stated. If vector borne, the most common form would be ulceroglandular with an ulcer at the introduction site and enlarged lymph nodes in that area. If waterborne, oropharyngeal would be most common. Among flying vectors, deer flies are often brought up but mosquitoes are also relevant as shown in this Swedish publication:

Reference
---------
Thelaus J, Andersson A, Broman T, et al: _Francisella tularensis_ subspecies _holarctica_ occurs in Swedish mosquitoes, persists through the developmental stages of laboratory-infected mosquitoes and is transmissible during blood feeding. Microb Ecol. 2014; 67(1): 96-107;  <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3907667/>

"Abstract
--------
In Sweden, mosquitoes are considered the major vectors of the bacterium _Francisella tularensis_ subsp. _holarctica_, which causes tularemia. The aim of this study was to investigate whether mosquitoes acquire the bacterium as aquatic larvae and transmit the disease as adults. Mosquitoes sampled in a Swedish area where tularemia is endemic (Orebro) were positive for the presence of _F. tularensis_ deoxyribonucleic acid throughout the summer. Presence of the clinically relevant _F. tularensis_ subsp. _holarctica_ was confirmed in 11 out of the 14 mosquito species sampled. Experiments performed using laboratory-reared _Aedes aegypti_ confirmed that _F. tularensis_ subsp. _holarctica_ was transstadially maintained from orally infected larvae to adult mosquitoes and that 25% of the adults exposed as larvae were positive for the presence of _F. tularensis_-specific sequences for at least 2 weeks. In addition, we found that _F. tularensis_ subsp. _holarctica_ was transmitted to 58% of the adult mosquitoes feeding on diseased mice. In a small-scale in vivo transmission experiment with _F. tularensis_ subsp. _holarctica_-positive adult mosquitoes and susceptible mice, none of the animals developed tularemia. However, we confirmed that there was transmission of the bacterium to blood vials by mosquitoes that had been exposed to the bacterium in the larval stage. Taken together, these results provide evidence that mosquitoes play a role in disease transmission in part of Sweden where tularemia recurs."  - ProMED Mod.LL]

[HealthMap/ProMED-mail map of Sweden:
<http://healthmap.org/promed/p/108>]
Date: Mon 12 Aug 2019 16:01 CEST +02:00
Source: The Local [edited]
<https://www.thelocal.se/20190812/rabbit-fever-hundreds-infected-as-outbreak-grows-in-sweden>

Swedish health authorities have warned an outbreak of rabbit fever (tularemia) is expected to grow, with hundreds of people affected so far.

A total of 212 confirmed cases have been reported to The Public Health Agency of Sweden (Folkhallsomyndigheten) so far in 2019, sharply increasing from late July 2019. That is twice as many as in a normal year.

But Sweden has not yet seen the end of it, the authority warned on [Mon 12 Aug 2019]. "Since the number of cases (of rabbit fever) is usually at its highest in September, the outbreak is expected to grow further in the coming weeks," it wrote in a statement.

Most cases have been reported in Dalarna, Gavleborg, and Orebro counties in central Sweden, but in the past week Vasterbotten and Norrbotten have also seen an increase, often limited to a specific area.

Many of those affected by the disease have been infected via mosquito bites.  [Byline: Emma Loefgren]
=========================
[_Francisella tularensis_ subsp. _tularensis_ (type A) is associated with lagomorphs (rabbits and hares). Wild rodents are also frequently infected, and occurrence of human cases is usually linked to these host species. _F. tularensis_ is transmitted primarily by ticks and biting flies, and is highly virulent for humans and domestic rabbits.

Tularemia is largely confined to the Northern Hemisphere and is not normally found in the tropics or the Southern Hemisphere. _F. tularensis_ subspecies _holarctica_ naturally infects several mammalian wildlife species in northern Europe, in particular, mice, rabbits, hares, beavers, voles, lemmings, and muskrats. The ticks _Dermacentor reticularis_ and _Ixodes ricinus_ are vectors for the bacterium, although previous research has suggested that mosquito bites are the most frequent route of transmission to humans in Sweden.

In addition to vector transmission, tularemia may be spread via contact with infected animals or environmental fomites by inhalation, or by ingestion of the poorly cooked flesh of infected animals or contaminated water.

Tularemia can be transmitted by aerosol, direct contact, ingestion, or arthropods. Inhalation of aerosolized organisms (in the laboratory or as an airborne agent in an act of bioterrorism) can produce a pneumonic form. Direct contact with, or ingestion of, infected carcasses of wild animals (such as cottontail rabbit) can produce the ulceroglandular, oculoglandular, oropharyngeal (local lesion with regional lymphadenitis), or typhoidal form. Immersion in or ingestion of contaminated water can result in infection in aquatic animals. Ticks can maintain infection transstadially [pathogen remains with the vector from one life stage ("stadium") to the next] and transovarially [transmission of a pathogen from an organism (as a tick) to its offspring by infection of eggs in its ovary], making them efficient reservoirs and vectors.

The manifestations of infection in this growing outbreak in parts of Sweden are not stated. If vector borne, the most common form would be ulceroglandular with an ulcer at the introduction site and enlarged lymph nodes in that area. If waterborne, oropharyngeal would be most common. Among flying vectors, deer flies are often brought up but mosquitoes are also relevant as shown in this Swedish publication:

Thelaus J, Andersson A, Broman T, et al: _Francisella tularensis_ subspecies holarctica occurs in Swedish mosquitoes, persists through the developmental stages of laboratory-infected mosquitoes and is transmissible during blood feeding. Microb Ecol. 2014; 67(1): 96-107; <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3907667/>

"Abstract
--------
In Sweden, mosquitoes are considered the major vectors of the bacterium _Francisella tularensis_ subsp. _holarctica_, which causes tularemia. The aim of this study was to investigate whether mosquitoes acquire the bacterium as aquatic larvae and transmit the disease as adults. Mosquitoes sampled in a Swedish area where tularemia is endemic (Orebro) were positive for the presence of _F. tularensis_ deoxyribonucleic acid throughout the summer. Presence of the clinically relevant _F. tularensis_ subsp. _holarctica_ was confirmed in 11 out of the 14 mosquito species sampled. Experiments performed using laboratory-reared _Aedes aegypti_ confirmed that _F. tularensis_ subsp. _holarctica_ was transstadially maintained from orally infected larvae to adult mosquitoes and that 25% of the adults exposed as larvae were positive for the presence of _F. tularensis_-specific sequences for at least 2 weeks. In addition, we found that _F. tularensis_ subsp. _holarctica_ was transmitted to 58% of the adult mosquitoes feeding on diseased mice. In a small-scale in vivo transmission experiment with _F. tularensis_ subsp. _holarctica_-positive adult mosquitoes and susceptible mice, none of the animals developed tularemia. However, we confirmed that there was transmission of the bacterium to blood vials by mosquitoes that had been exposed to the bacterium in the larval stage. Taken together, these results provide evidence that mosquitoes play a role in disease transmission in part of Sweden where tularemia recurs."  - ProMED Mod.LL]

[Maps of Sweden:
<http://www.ezilon.com/maps/images/europe/Swedish-political-map.gif>
and <http://healthmap.org/promed/p/108>]
Date: Wed 7 Aug 2019, 10:47 AM CEST
Source: The Local SE [edited]
<https://www.thelocal.se/20190807/harpest-what-you-need-to-know-about-the-mosquito-borne-disease>

There have been several reported cases of tularemia or rabbit fever, known as 'harpest' in Sweden, this summer [2019], mostly in the north and centre of the country.  The animals most likely to carry the disease are wild hares, hence the name rabbit fever, and rodents, but it can also be transferred to humans via mosquito bites and occasionally tick bites. It's also possible for the infection to be transmitted by inhaling dust or drinking water that is contaminated by urine or feces from animals with the disease, according to Swedish healthcare service 1177. The disease cannot be carried from human to human.

It is too early to measure the exact extent of the disease this year [2019], since statistics from the Public Health Agency won't be available until later. But the Swedish Veterinary Institute has warned of several findings of dead animals that had been infected with the disease, and a "suspected outbreak".

A total of 33 people in the Gavleborg region have been affected by rabbit fever since the start of July [2019], according to regional healthcare authorities. In most cases, the patients had been infected in the Ljusdal area, and one case related to a patient who became sick after cleaning out a barn.

At least 12 people have been affected by rabbit fever in the Dalarna region alone, a doctor in communicable diseases told SVT Dalarna, and he said the figure was expected to increase.

"It looks like there will be a lot of cases this year [2019], more than last year [2018]," doctor Anders Lindblom said, adding: "Not everyone [who is affected by rabbit fever] seeks medical care and reports the illness."

At least a further 5 people have confirmed cases of rabbit fever in Norrbotten too. Sweden had a large outbreak of rabbit fever in 2015, when 859 people across the country suffered from the illness, the majority of them in Norrbotten and Vasterbotten. In 2018, 107 cases were reported across Sweden, with Dalarna the most severely affected region.

Symptoms of rabbit fever typically begin with swelling or tenderness in the lymph node and a skin lesion at the site of any bite or direct contact, followed occasionally by symptoms that can include a skin rash, nausea, and headaches.

The best way to protect yourself from infection is to avoid mosquito bites as much as possible (either by using repellents, or wearing long, loose clothing when going outside between dusk and dawn), and being especially careful if you need to touch a dead animal such as a rodent or hare, using precautions such as a face mask and gloves.
===================
[_Francisella tularensis_ subsp. _tularensis_ (Type A) is associated with lagomorphs (rabbits and hares). Wild rodents are also frequently infected, and occurrence of human cases is usually linked to these host species. _F. tularensis_ is transmitted primarily by ticks and biting flies, and is highly virulent for humans and domestic rabbits.

Tularemia is largely confined to the Northern Hemisphere and is not normally found in the tropics or the Southern Hemisphere. _F. tularensis_ subspecies _holarctica_ naturally infects several mammalian wildlife species in northern Europe, in particular, mice, rabbits, hares, beavers, voles, lemmings, and muskrats. The ticks _Dermacentor reticularis_ and _Ixodes ricinus_ are vectors for the bacterium, although previous research has suggested that mosquito bites are the most frequent route of transmission to humans in Sweden.

In addition to vector transmission, tularemia may be spread via contact with infected animals or environmental fomites by inhalation, or by ingestion of the poorly cooked flesh of infected animals or contaminated water. - ProMED Mod.PMB]

[Tularemia can be transmitted by aerosol, direct contact, ingestion, or arthropods. Inhalation of aerosolized organisms (in the laboratory or as an airborne agent in an act of bioterrorism) can produce a pneumonic form. Direct contact with, or ingestion of, infected carcasses of wild animals (such as cottontail rabbit) can produce the ulceroglandular, oculoglandular, oropharyngeal (local lesion with regional lymphadenitis), or typhoidal form. Immersion in or ingestion of contaminated water can result in infection in aquatic animals. Ticks can maintain infection transstadially [pathogen remains with the vector from one life stage ("stadium") to the next] and transovarially [transmission of a pathogen from an organism (as a tick) to its offspring by infection of eggs in its ovary], making them efficient reservoirs and vectors. - ProMED Mod.LL]

[HealthMap/ProMED-mail map:
Sweden: <http://healthmap.org/promed/p/108>]
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