[Leish-l] Leishmaniasis - Argentina: epidemic potential

Mon Mar 30 09:20:45 BRT 2009

Dear colleague,
You are perfectly right. This is one of the parameters I was including  
in the more general term : prevalence rate (could be "dynamics") of  
transmission.
Best wishes
P. Bastien

> Dear sir,
> it should be noticed that the proportion of human/dog infected
> certainly is very influenced by the preference of sand flies for biting
> on humans vs. dogs. Are there comparisons in Americas and Europe?
>   Does anyone disagree?
>
> Sincerely yours
> Carlos Brisola Marcondes
> Florianópolis (SC)
> Brazil
> ----- Original Message ----- From: "Patrick Bastien"
> <patrick.bastien at univ-montp1.fr>
> To: "Gordon Hamilton" <j.g.c.hamilton at biol.keele.ac.uk>
> Cc: "fred opperdoes" <fred.opperdoes at uclouvain.be>;
> <Leish-l at lineu.icb.usp.br>; "Chang, Kwang-Poo"
> <KwangPoo.Chang at rosalindfranklin.edu>
> Sent: Thursday, March 26, 2009 2:13 PM
> Subject: Re: [Leish-l] Leishmaniasis - Argentina: epidemic potential
>
>
> Does this statement include "healthy" (or asymptomatic) carriers ?
>
> We (and others in Southern Europe) found a figure around 80% of
> infected dogs by PCR (including "healthy" carriers). Considering we
> have 150000 dogs in our region, we should then have 2500 persons
> infected. We have at most 10 patients per year with VL, perhaps 20
> with L. infantum CL (?).
> So "infected persons" must include healthy carriers.
> Do we have 2470 healthy carriers in our region ? This is not
> impossible, as our colleagues from Nice found a reasonable figure of
> 1.6 % healthy carriers among blood donors in Monaco in 1999 (it should
> be noted that Spanish authors have then found much greater figures).
> If this (low) rate is right, this would mean 16000 healthy carriers in
> our region (that counts 1 million inhabitants) ! i.e. far more than
> the 2500 expected from the "one person infected for every 60 infected
> dogs".
> But !... it also may all depend upon the prevalence of transmission.
> In France, transmission occurs at low rates and in a very limited
> period of time in the year. The situation must be different in an area
> where transmission rates are high and transmission occurs throughout
> the year.
>
> Hoping this brings a piece to the puzzle...
>
> Cordialement
> P. Bastien
>
> Professeur Patrick Bastien
> Laboratoire de Parasitologie-Mycologie, Faculté de Médecine
> Equipe "Mécanismes biologiques fondamentaux des eucaryotes ancestraux"
> UMR2724 CNRS / Université Montpellier 1 / IRD
> Centre National de Référence des Leishmania
> 99 rue Auguste Broussonet
> 34090 Montpellier
> France
> Tel: +33(0)499 23 26 78 (sec) or +33(0)467 63 27 51 (direct)
> Fax: +33(0)499 23 26 62
>
>
> Gordon Hamilton <j.g.c.hamilton at biol.keele.ac.uk> a Ã©critÂ :
>
>> Dear All,
>>
>> the article contains the following interesting statement,
>>
>> "The analysis of the experience from Brazil and Paraguay indicates
>> that there is a probability of having one person infected for every
>> 60 infected dogs"
>>
>> does anyone know the source of this information and is it true?
>>
>>
>> many thanks
>>
>>
>> Gordon Hamilton
>>
>>
>>
>>  ----- Original Message -----
>>  From: Chang, Kwang-Poo
>>  To: Laila Nimri ; fred opperdoes ; Leish-l at lineu.icb.usp.br
>>  Sent: Saturday, March 21, 2009 3:25 PM
>>  Subject: Re: [Leish-l] Leishmaniasis - Argentina: epidemic potential
>>
>>
>>  To: Prof. Laila Nimri and all
>>
>>
>>
>>  The issue appears to be a language translation problem. I was told
>> that all blood sucking flies are referred to as "mosquito" in
>> Spanish.
>>
>>
>>
>>  KP
>>
>>
>>
>>
>> ------------------------------------------------------------------------------
>>
>>  From: leish-l-bounces at lineu.icb.usp.br
>> [mailto:leish-l-bounces at lineu.icb.usp.br] On Behalf Of Laila Nimri
>>  Sent: Thursday, February 26, 2009 1:53 AM
>>  To: fred opperdoes; Leish-l at lineu.icb.usp.br
>>  Subject: Re: [Leish-l] Leishmaniasis - Argentina: epidemic potential
>>
>>
>>
>>  Just to correct a very important information about the vector of
>> Visceral leishmaniasis, it is definitely not a mosquito, it is a
>> sand fly of the genus Lutzomyia as mentioned correctly below or a
>> Phlebotomus. The environmental or climatic changes that affect
>> mosquitoes might have affected the sand flies and lead to the
>> emergence of the disease.
>>
>>
>>
>>  Prof. Laila Nimri
>>
>>
>> ------------------------------------------------------------------------------
>>
>>  From: leish-l-bounces at lineu.icb.usp.br
>> [leish-l-bounces at lineu.icb.usp.br] On Behalf Of fred opperdoes
>> [fred.opperdoes at uclouvain.be]
>>  Sent: Thursday, February 26, 2009 8:21 AM
>>  To: Leish-l at lineu.icb.usp.br
>>  Subject: [Leish-l] Leishmaniasis - Argentina: epidemic potential
>>
>>    Date: Wed, 25 Feb 2009 21:23:15 -0500 (EST)
>>    From: ProMED-mail <promed at promed.isid.harvard.edu>
>>    Subject: PRO/AH/EDR> Leishmaniasis - Argentina: epidemic potential
>>
>>    LEISHMANIASIS - ARGENTINA: EPIDEMIC POTENTIAL
>>    ***********************************************
>>    A ProMED-mail post
>>    <http://www.promedmail.org>
>>    ProMED-mail is a program of the
>>    International Society for Infectious Diseases
>>    <http://www.isid.org>
>>
>>    Date: Tue 24 Feb 2009
>>    Source: Datachaco.com [trans. Mod JGM, edited]
>>    <http://datachaco.com/noticia.php?numero=17399>
>>
>>
>>    The occurrence of cases of yellow fever made people pay attention to
>>    mosquito-borne diseases, and dengue fever, which is currently
>>    attacking with unusual strength in Paraguay, set another alarm in
>>    Chaco, Corrientes, and Misiones provinces, which share borders with
>>    Paraguay and Bolivia.
>>
>>    However, a new emerging disease has become the main epidemic threat
>>    in Argentina: Visceral leishmaniasis. This little known disease is
>>    being analyzed now as a cause for a sanitary red alert in Argentina.
>>
>>    Visceral leishmaniasis is also caused by a mosquito-borne parasite.
>>    There is no vaccine for this disease, and therapy is instituted only
>>    once a case is clearly defined. Its mortality rate is around 8 per
>>    cent, and it has a particular feature: Dogs may act as reservoirs for
>>    the parasite.
>>
>>    A summary of the life cycle of the parasite indicates that
>>    _Lutzomyia_ insects infect dogs. These animals develop the disease
>>    and transmit the parasite to another insect vector, which now is
>>    capable of transmitting visceral leishmaniasis to humans. There is no
>>    human-to-human transmission.
>>
>>    Since the very 1st case was reported in 2006, 36 persons have been
>>    affected, and there are 4 deceased patients. The possibility of a
>>    rapid increase in the number of cases is a reason for concern.
>>
>>    Last week 2 cases of visceral leishmaniasis were reported in Posadas.
>>    One is an 18-year-old woman, and the other is a 21-year-old man, who
>>    separately developed the symptoms of the disease. Some personnel from
>>    the army are currently collaborating with municipal authorities in
>>    Posadas for cleaning wastelands, which are considered breeding places
>>    for insect vectors.
>>
>>    This health problem has become quite dangerous and important in the
>>    main cities in Misiones province, and specialists warn that the
>>    disease may reach other provinces in the short term.
>>
>>    "We are observing that the vector is spreading fast, and 2 corridors
>>    have been established, one directing towards Resistencia and the
>>    other one towards Corrientes. Also, the northern area of Entre Rios,
>>    as well as Santa Fe, and Cordoba are vulnerable places. The mosquito
>>    vector for visceral leishmaniasis has become an urban-living insect,
>>    so there is a substantial risk for its presence in big urban
>>    centers," explained Dr. Daniel Salomon, from the National Center for
>>    Epidemics in Argentina's Ministry of Health.
>>
>>    "It is quite difficult to implement preventive measures, because
>>    people are so in love with their pets," commented Dr. Salomon. There
>>    are very few options for controlling the spread of the disease apart
>>    from sacrificing sick animals.
>>
>>    In 2004, the 1st dog infected with the causative agent of visceral
>>    leishmaniasis was detected. When 40 cases were reported in Misiones
>>    province, the Ministry of Health issued a red alert. Nonetheless, the
>>    current situation is much worse. In Posadas, it was determined that
>>    7000 dogs actually have the parasite. Additionally, there are 300
>>    infected dogs in Corrientes, and it is worth mentioning that in its
>>    capital city, there are thousands of homeless dogs considered to be
>>    infected with the parasite.
>>
>>    The analysis of the experience from Brazil and Paraguay indicates
>>    that there is a probability of having one person infected for every
>>    60 infected dogs. There is a high risk for an epidemic.
>>
>>    Sanitary authorities recommend that pets must not be carried to the
>>    areas considered to be at risk. It is also advisable not to transport
>>    dogs from the affected regions to other areas in the country. The
>>    idea is to cut the transmission cycle of the parasite. Those persons
>>    who may visit the northern part of Argentina must be immunized
>>    against yellow fever as an ordinary preventive measure, and they must
>>    leave their pets at home as an additional preventive measure.
>>
>>    "Visceral leishmaniasis was present in the northern part of South
>>    America until migrating workers started moving it towards the south.
>>    In early 2000, there were some important outbreaks in Campo Grande do
>>    Sul and in Asuncion, where the average number of persons infected is
>>    around 70 per year. In Brazil there are around 4000 cases and 200
>>    deaths per year," pointed out Dr. Salomon, who had been doing some
>>    field work during the past few weeks in the Litoral provinces.
>>
>>    He also added: "There is a trend for an increase in visceral
>>    leishmaniasis, so the disease may spread, and it is expected to have
>>    more cases."
>>
>>    Climate changes and deforesting seem to be the main explanations for
>>    the migration of mosquito-borne diseases. However, trying to justify
>>    the occurrence of emergent diseases only because of reasons inherent
>>    to nature itself may exonerate provincial and municipal authorities
>>    for not complying with their obligations with respect to the
>>    implementation of disease control programs and cleaning empty lots.
>>
>>    Consequently, now there are many public accusations between Misiones,
>>    Corrientes, and Chaco health officers. These persons, now that there
>>    are cases of visceral leishmaniasis, immediately try to explain that
>>    transmission may have taken place outside their respective
>>    jurisdictions. The clear point is that the mosquito vector appears
>>    because of lack of public hygiene.
>>
>>    - --
>>    Communicated by:
>>    ProMED-mail <promed at promedmail.org>
>>
>>    [Leishmaniasis has been slowly spreading in northern Argentina over
>>    the past decades (Salomon O et al. First visceral leishmaniasis focus
>>    in Argentina. Mem Inst Oswaldo Cruz. 2008;103:109-11
>>
>> <http://www.ncbi.nlm.nih.gov/pubmed/18368242?ordinalpos=9&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum>).
>>
>>    The ecology of the vector has been changing, and increasing
>>    urbanization has been suggested as one of the explanations (Salomon
>>    OD et al. Phlebotominae (Diptera: Psycodidae) fauna in the Chaco
>>    region and Cutaneous Leishmaniasis transmission patterns in
>>    Argentina. Mem Inst Oswaldo Cruz. 2008;103:578-84
>>
>> <http://www.ncbi.nlm.nih.gov/pubmed/18949328?ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum>).
>>     - Mod.EP]
>>
>>
>>
>> ------------------------------------------------------------------------------
>>
>>
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>
>
> "L'archer est un modèle pour le sage. Quand il a manqué le milieu de  
>  la cible,
> il en cherche la cause en lui-même."   Confucius
>
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