Wüstenschiff

Malaria: Neues vom Erreger
02.06.2009 - Informationsdienst Wissenschaft

Mit einer klebrigen Hülle aus Proteinen umgibt sich der Malaria-Erreger in einer bestimmten Phase seiner Vermehrung. Das haben Wissenschaftlerinnen vom Zentrum für Infektionsforschung der Uni Würzburg herausgefunden. Die neue Erkenntnis könnte für die Entwicklung von Impfstoffen bedeutsam sein ... mehr
_______________________________________________

Neuer Malariaerreger entdeckt
02.06.2009 - Deutsches Ärzteblatt

Montpellier – Wissenschaftler aus Frankreich und Gabun haben in dem afrikanischen Land eine neue Spezies des Malariaparasiten entdeckt, der Menschenaffen infiziert. Nach ihrem Bericht in PLoS Pathogens (2009; 5: e1000446) ist der Plasmodium gaboni getaufte Erreger eng mit Plasmodium falciparum verwandt, dem Erreger der gefürchteten Malaria tropica. Von den etwa 200 verschiedenen Arten der Malariaerreger galten lange Zeit nur vier, nämlich Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale und Plasmodium vivax, als klinisch relevant für den Menschen ... mehr


Gruß
Birgitt

Mensch gegen Moskito
07.06.2009 - Spiegel

Malariaerreger entwickeln immer neue Resistenzen gegen Medikamente. Nun hat ein zuvor hochwirksames Mittel seine Wirkung verloren. Im Kampf gegen die Parasiten wollen Forscher jetzt auf Laserwaffen und intelligente Insektizide setzen ... mehr

Gruß
Birgitt

MALARIA DRUG, ADVERSE EVENTS - INDIA: REQUEST FOR INFORMATION
*************************************************************
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: Mon 6 Jul 2009
Source: Yahoo News - India [edited]
<http://in.news.yahoo.com/20/20090705/14 ... for-m.html>


Tablets distributed by the district health department in a
malaria-prone area have created havoc in Chiplun Taluk, and the
tablets have been recalled and collected by the health department for
investigative tests in government laboratories. One person died after
consuming anti-malaria tablets supplied by the health department last
[5 Jul 2009] night.

From the same area, 39 others who consumed tablets have also been
admitted to Dadar primary healthcare centre [PHC] for vomiting and
drowsiness; 2 persons from the villages died of malaria infections in
the last week of June 2009.

The health department declared Akale, Kadwad, Tiware, Tiwadi, Rictoli,
Kalkawanwali and Nandiwase villages as malaria-prone areas and started
distributing chloroquine phosphate and primaquine tablets in the area.
Yesterday [5 Jul 2009] in Akale camp, 64 patients suspected to have
infections were given the tablets. Among them, 39 patients faced
serious problems with vomiting and have been admitted to the PHC.

--
Communicated by:
ProMED-mail <promed@promedmail.org>

[Chloroquine phosphate is a very well known drug, and although nausea
and vomiting may be seen after administration, especially in children,
drowsiness is not a known adverse reaction. Therefore, the unexpected
adverse reaction could be due to the drug being substandard. A recent
study on the quality of drugs in India found that 12 percent of drugs
sampled in Delhi and 5 percent of drugs sampled in Chennai were
substandard: (Bate R et al. Pilot study of essential drug quality in
two major cities in India. PLoS One 2009 Jun 23;4(6):e6003). - Mod.EP]

[The drugs could also have been inadvertently contaminated with some
toxic substance. - Mod.JW]

Sex macht Fliegen-Weibchen unattraktiv
18.07.2009 - Zeit

Münster (dpa) - Männliche Fruchtfliegen «fliegen» nur auf Weibchen, die nicht nach Sex schmecken: Forscher der Universitäten Münster und Harvard (USA) haben ein Sexualpheromon entdeckt, das vom männlichen Geschlechtsteil auf das Weibchen übertragen wird [...] Die Forschungsergebnisse könnten nun weiterentwickelt werden, um beispielsweise die Verbreitung von Moskitos einzudämmen, die für Menschen gefährliche Krankheiten wie Malaria übertragen ... mehr

Gruß
Birgitt

Forscher impfen Patienten mit Mückenstichen

Kann man Malaria mit Malaria bekämpfen? Vermutlich ja, wie ein Experiment vermuten lässt. Freiwillige ließen sich ein Medikament verabreichen und zugleich von infizierten Mücken stechen. Danach waren sie immun gegen die Krankheit, die jedes Jahr Millionen tötet. mehr...

Grüsse
Alexander

MALARIA, ARTEMISININ RESISTANCE - SOUTHEAST ASIA
************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>

Artemisinin resistance in Southeast Asia
----------------------------------------
2 studies in this week's [30 Jul 2009] issue of New England Journal
of Medicine highlight the growing problem of resistance to
artemisinins in _Plasmodium falciparum_ malaria in Southeast Asia. - Mod.EP]


[1]
Date: Thu 30 Jul 2009
Source: New England Journal of Medicine [edited]
<http://content.nejm.org/cgi/content/full/361/5/455>


[Ref: Dondorp AM et al: Artemisinin resistance in _Plasmodium
falciparum_ malaria. N Engl J Med 2009; 361: 455-67]
----------------------------------------------------------------------
Abstract
--------
Background
----------
Artemisinin-based combination therapies are the recommended 1st-line
treatments of falciparum malaria in all countries with endemic
disease. There are recent concerns that the efficacy of such
therapies has declined on the Thai-Cambodian border, historically a
site of emerging antimalarial-drug resistance.

Methods
-------
In 2 open-label, randomized trials, we compared the efficacies of 2
treatments for uncomplicated falciparum malaria in Pailin, western
Cambodia, and Wang Pha, northwestern Thailand: oral artesunate given
at a dose of 2 mg per kilogram of body weight per day, for 7 days,
and artesunate given at a dose of 4 mg per kilogram per day, for 3
days, followed by mefloquine at 2 doses totaling 25 mg per kilogram.
We assessed in vitro and in vivo _Plasmodium falciparum_
susceptibility, artesunate pharmacokinetics, and molecular markers of
resistance.

Results
-------
We studied 40 patients in each of the 2 locations. The overall median
parasite clearance times were 84 hours (interquartile range, 60 to
96) in Pailin and 48 hours (interquartile range, 36 to 66) in Wang
Pha (P less than 0.001). Recrudescence confirmed by means of
polymerase-chain-reaction assay occurred in 6 of 20 patients (30
percent) receiving artesunate monotherapy and 1 of 20 (5 percent)
receiving artesunate-mefloquine therapy in Pailin, as compared with 2
of 20 (10 percent) and 1 of 20 (5 percent), respectively, in Wang Pha
(P=0.31). These markedly different parasitologic responses were not
explained by differences in age, artesunate or dihydroartemisinin
pharmacokinetics, results of isotopic in vitro sensitivity tests, or
putative molecular correlates of _P. falciparum_ drug resistance
(mutations or amplifications of the gene encoding a multidrug
resistance protein [PfMDR1] or mutations in the gene encoding
sarco-endoplasmic reticulum calcium ATPase6 [PfSERCA]). Adverse
events were mild and did not differ significantly between the 2
treatment groups.

Conclusions
-----------
_P. falciparum_ has reduced in vivo susceptibility to artesunate in
western Cambodia as compared with northwestern Thailand. Resistance
is characterized by slow parasite clearance in vivo without
corresponding reductions on conventional in vitro susceptibility
testing. Containment measures are urgently needed.

******
[2]
Date: Thu 30 Jul 2009
Source: New England Journal of Medicine [edited]
<http://content.nejm.org/cgi/content/full/361/5/540>


[Ref: Noedl H et al: Artemisinin-resistant malaria in Asia. N Engl J
Med 2009; 361: 540-1]
----------------------------------------------------------------------
The study compares resistance to dihydroartemisinin and mefloquine in
Bangladesh, western and eastern Thailand, and Cambodia. The mean
log10 concentration of dihydroartemisinin resulting in a 50 percent
inhibition (IC50) of parasite growth in vitro was 3 times higher in
Cambodia compared to Bangladesh with an increasing gradient from
western to eastern Thailand.

The mean log10 concentration of mefloquine resulting in a 50 percent
inhibition (IC50) of parasite growth in vitro was 3 times highest in
Western and Eastern Thailand and lowest in Bangladesh.

The study concludes:
"These findings suggest that the increased failure rate of
artemisinin-based therapies can probably be attributed to decreased
artemisinin susceptibility in the east rather than to major regional
differences in mefloquine sensitivity.

In southeastern Bangladesh, an area where until very recently
artemisinin-based therapies have not been extensively used,
artemisinin sensitivity remains high. These data indicate that it is
unlikely that artemisinin resistance has spread across Thailand, and
we found high susceptibility in Bangladesh."

--
Communicated by:
ProMED-mail
<promed@promedmail.org>

[The 2 studies highlight a focus in Cambodia and eastern Thailand
with reduced sensitivity to artemisinins. This is worrisome because
artemisinins, alone and in combination with other antimalarials, are
the main drug used for chemotherapy throughout Asia and Africa. The
studies are also worrisome because the areas where this resistance
has been found, are the same areas where chloroquine resistance was
first described almost 50 years ago and where
sulfadoxine/pyrimethamine (fansidar) and mefloquine resistance also developed.

Genetic studies have indicated that the chloroquine resistant _P.
falciparum_ strain, which spread throughout Africa in the 1980s did
indeed come from Southeast Asia (Mita T et al: Spread and evolution
of _Plasmodium falciparum_ drug resistance. Parasitol Int 2009 Apr
23. E-pub ahead of print; abstract available at
<http://www.ncbi.nlm.nih.gov/pubmed/19393762>).

A recent study based on mathematical modelling suggests that the
focus of artemisinin resistance can be contained by use of optimal
drug dosing (Maude RJ et al: The last man standing is the most
resistant: eliminating artemisinin-resistant malaria in Cambodia.
Malar J 2009 8: 31; available at
<http://www.malariajournal.com/content/8/1/31>). However, resistance
is most probably driven by counterfeit drugs, substandard
preparation, and distribution of artemisinin as single therapy
compared to combinations and sale of single doses. This is difficult
to improve in countries, which cannot enforce quality control of the
drugs used and control distribution through prescriptions. Perhaps
control should be based on enhanced vector control especially
impregnated bed nets. - Mod.EP]

[A map of Southeast Asia is available at
<http://www.lib.utexas.edu/maps/middle_e ... f_2007.jpg>.
- Sr.Tech.Ed.MJ]

Malaria stammt vom Schimpansen

Die Malaria ist ein Geschenk unserer nächsten Verwandten im Tierreich: Der Erreger der Tropenkrankheit ist von Schimpansen im äquatorialen Afrika auf den Menschen übergegangen. mehr...

Grüsse
Alexander

Vier Buchstaben gegen Malaria

Alle 30 Sekunden stirbt ein Mensch auf der Welt an Malaria. Möglicherweise haben Tübinger Tropenmediziner jetzt einen Impfstoff gegen die Seuche entwickelt: RTS,S mehr...

Grüsse
Alexander

Malariabekämpfung: Wettlauf gegen die Zeit

"Die Krankheit ausrotten", so lautete lange Zeit das Ziel der Weltgesundheitsorganisation (WHO) im Kampf gegen Malaria. Moskito und Erreger sollten wie einst in Europa auch aus Afrika und Asien endgültig verschwinden. mehr…

Grüsse
Alexander

Kräuter-Export
Wie deutsche Naturheilkundler den Kampf gegen Malaria behindern
27.08.2009 | © DIE ZEIT

Die obersten Seuchenschützer in Genf sind nervös, und ausnahmsweise gilt ihre Sorge nicht der Schweinegrippe. Im Grenzgebiet zwischen Thailand und Kambodscha beobachtet die Weltgesundheitsorganisation (WHO) seit Monaten zunehmend Resistenzen gegen das Malariamittel Artemisinin. Dabei ruht auf dieser Substanz, gewonnen aus dem Einjährigen Beifuß (Artemisia annua), die ganze Hoffnung der WHO im Kampf gegen das Wechselfieber.

Die gefürchtete Resistenz wäre nicht entstanden, hätten die Patienten den Wirkstoff – wie empfohlen – als Kombinationspräparat mit einer anderen Substanz eingenommen. Doch dieser Plan scheitert. Immer wieder tauchen Mittel allein mit dem Wirkstoff auf, Fälschungen enthalten viel zu geringe Dosierungen, oder der Inhaltsstoff fehlt gleich ganz. Als sei das alles nicht schlimm genug, wird die Kampagne der WHO seit einiger Zeit auch noch aus Deutschland unterwandert ... mehr

Gruß
Birgitt

MALARIA, PLASMODIUM KNOWLESI - ASIA: BACKGROUND
***********************************************
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: Wed 9 Sep 2009
Source: BBC News [edited]
<http://news.bbc.co.uk/2/hi/health/8246063.stm>


_Plasmodium knowlesi_ malaria 'poses human threat'
--------------------------------------------------
An emerging new form of malaria poses a deadly threat to humans,
research has shown.

It had been thought the parasite _P. knowlesi_ infected only monkeys.
But it has recently been found to be widespread in humans in
Malaysia, and the latest study confirms that it can kill if not
treated quickly. The work, by an international team, appears in the
journal Clinical Infectious Diseases.

Although the new form of the disease has so far been concentrated in
Southeast Asia, the researchers warn that tourism to the region could
soon see cases appearing in Western countries too.

Malaria kills more than a million people each year. It is caused by
malaria parasites, which are injected into the bloodstream by
infected mosquitoes. Of the 4 species of malaria parasite that often
cause disease in humans, _P. falciparum_, found most commonly in
Africa, is the most deadly. Another parasite, _P. malariae_, found in
tropical and sub-tropical regions across the globe, has symptoms that
are usually less serious.

_P. knowlesi_ had been thought only to infect monkeys, in particular
long-tailed and pig-tailed macaques found in the rainforests of Southeast Asia.

But following work by a team at the University Malaysia Sarawak it
has now been recognised as a significant cause of disease in humans.
The latest study shows that _P. knowlesi_ can easily be confused with
_P. malariae_ under the microscope.

Speedy reproduction
-------------------
However, unlike its cousin, _P. knowlesi_ has the ability to
reproduce every 24 hours in the blood -- meaning infection is
potentially deadly.

Researcher Professor Balbir Singh said this meant early diagnosis and
treatment were crucial.

The researchers carried out tests on over 150 patients admitted to
hospital in Sarawak, Malaysian Borneo, between July 2006 and January
2008 with malaria infection.

They found that _P. knowlesi_ accounted for more than two-thirds of
the infections, resulting in a wide spectrum of disease.

Most cases of infection were uncomplicated and easily treated with
drugs, including chloroquine and primaquine.

However, around 1 in 10 patients had developed complications, such as
breathing difficulties and kidney problems, and 2 died.

Although the fatality rate was just under 2 percent, that made _P.
knowlesi_ as deadly as _P. falciparum_ malaria. The researchers
stress it is hard to determine an accurate fatality rate given the
small number of cases so far studied.

Low platelet count
------------------
All of the _P. knowlesi_ patients had a low blood platelet count,
significantly lower than that usually found for other types of
malaria. However, even though blood platelets are essential for blood
clotting, no cases of excessive bleeding or problems with clotting
were identified.

The researchers believe the low blood platelet count could be used as
a potential way to diagnose _P. knowlesi_ infections.

Professor Singh said: "The increase in tourism in Southeast Asia may
mean that more cases are detected in the future, including in Western
countries. Clinicians assessing a patient who has visited an area
with known or possible _P. knowlesi_ transmission should be aware of
the diagnosis, clinical manifestations, and rapid and potentially
serious course of _P. knowlesi_ malaria."

--
Communicated by:
ProMED-mail
<promed@promedmail.org>

[The BBC article refers to the paper by Daneshvar C et al: Clinical
and laboratory features of human _Plasmodium knowlesi_ infection.
Clin Infect Dis. 2009 Sep 15; 49: 852-60 (abstract available at
<http://www.journals.uchicago.edu/doi/ab ... alCode=cid>).

It is important to recognize _P. knowlesi_ infections, because of
their rapid progression.

Rapid tests for malaria diagnosis are increasingly used and it is
important to know that current rapid diagnostic test for malaria will
not detect _P. knowlesi_. - Mod.EP]

Enzym schützt den Organismus ohne den Erreger direkt anzugreifen
18.08.2009 - scinexx

Ein Enzym und ein bereits als Antioxidans bekannter Wirkstoff können den Körper gegen die Folgen einer Malariainfektion schützen und schwere Krankheitsverläufe verhindern. Der jetzt in der Fachzeitschrift “Proceedings of the National Academy of Sciences” (PNAS) Mechanismus greift den Erreger nicht direkt an, daher besteht keine Gefahr einer Resistenzbildung ... mehr

Gruß
Birgitt

Erreger verdrängt Wirkstoff aus seinem Verdauungstrakt
16.10.2009 - scinexx

Die bisherigen Waffen gegen die tödliche Tropenkrankheit Malaria drohen stumpf zu werden, immer häufiger treten Resistenzen auf. Australische Wissenschaftler haben nun jedoch eine Entdeckung gemacht, die eine effektivere Behandlung von Malaria ermöglichen könnte. Bei ihren Untersuchungen fanden sie heraus, wie sich der Malariaerreger der Wirksamkeit des gängigen Medikaments Chloroquin entzieht ... mehr

Gruß
Birgitt

Hoffen auf Malaria-Impfung - Konferenz in Nairobi

Alle 30 Sekunden stirbt ein Kind an Malaria. Die meisten tödlichen Malariafälle - etwa 90 Prozent - treten in Afrika auf. Derzeit wird an 20 Standorten in Afrika ein Impfstoff erprobt. Die Erfahrungen damit stehen im Mittelpunkt einer am Montag gestarteten Konferenz im kenianischen Nairobi. mehr...

Grüsse
Alexander

MALARIA, AUTOCHTHONOUS - ITALY: (LATINA), REQUEST FOR INFORMATION
*****************************************************************
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: Thu 5 Nov 2009
Source: Corriera Della Sera [edited]
<http://roma.corriere.it/roma/notizie/cr ... 2853.shtml>


Dr Fabrizio Soscia, chief of the department of infectious diseases at the
Civil Hospital of Latina, reassured the community after the discovery of a
case of malaria contracted by a tourist in Rome after a short stay near
Lake Fondi (Latina).

The Roman visitor, who stayed in the area between Monte San Biagio and
Fondi, is well after being treated at the Spallanzani Hospital in Rome. The
patient had not been abroad, and, therefore, the Ministry of Health has
initiated a surveillance of the anopheline mosquitoes in the area.

WHO declared Italy free from malaria in 1970, and this is the 1st case of
malaria in which the person was infected in Italy since then.

--
Professor Beniamino Cenci Goga, DVM, PhD, mECVPH
Facoltà di Medicina Veterinaria di Perugia
<cencigog@unipg.it>

[The story implies an incubation period of 2-3 months, suggesting that the
infection was with _Plasmodium vivax_. Lake Fondi is part of the Pontine
marshes, an area endemic for malaria until drainage works were completed in
the 1930s [subsequently sabotaged by the Nazis in world war two, but later
drained again. - Mod.SH].

It is conceivable that malaria may have returned to the area, but other
possibilities exist. The patient could have been infected elsewhere by
mosquitoes transmitting malaria from asymptomatic gametocyte carriers, and
this could have taken place anywhere.

ProMED-mail reported similarly unexplained cases from Virginia (United
States) in 2002 (PRO/EDR> Malaria - United States (Virginia)
20020907.5250). We would welcome further information about this case. - Mod.EP]