[Leish-l] Leishmaniasis - Argentina: epidemic potential

Mon Mar 30 08:32:50 BRT 2009

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

> 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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