H5N1

Europe at risk from spread of tropical insect-borne diseases

Via The Guardian: Europe at risk from spread of tropical insect-borne diseases. Excerpt:

Insect-borne diseases such as dengue fever, leishmaniasis and encephalitis are on the rise and are now threatening to spread into many areas of Europe, scientists have warned.  

Outbreaks of these illnesses are increasing because of climate change and the expansion of international travel and trade, the European Congress of Clinical Microbiology and Infectious Diseases was told in Amsterdam on Saturday. 

Even previously unaffected areas in higher latitudes and altitudes, including some parts of northern Europe, are at risk of outbreaks unless action is taken to improve surveillance and data sharing, the researchers said. An adult female mosquito seen under a microscope. 

“Climate change is not the only, or even the main, factor driving the increase in vector-borne diseases across Europe, but it is one of many factors alongside globalisation, socioeconomic development, urbanisation and widespread changes to land use which need to be addressed to limit the importation and spread,” said the lead author Professor Jan Semenza, of the European Centre for Disease Prevention and Control in Stockholm. 

This point was backed by Giovanni Rezza, of the Istituto Superiore di Sanità in Rome. “Lessons from recent outbreaks of the West Nile virus in North America and the chikungunya virus in the Caribbean and Italy highlight the importance of assessing future vector-borne disease risks,” he said.  

Global warming has allowed mosquitoes, ticks and other disease-carrying insects to proliferate, adapt to different seasons and invade new territories across Europe over the past decade, with accompanying outbreaks of dengue in France and Croatia, malaria in Greece, West Nile fever in south-east Europe and chikungunya in Italy and France. 

Worryingly, the authors said, this might only be the tip of the iceberg. “Mediterranean Europe is now a part-time tropical region, where competent vectors like the tiger mosquito are already established,” added Rezza. And in future, hotter and wetter weather could provide ideal conditions for the Asian tiger mosquito, which spreads the viruses that cause dengue and chikungunya, to breed and expand across large parts of Europe, including the south and east of the UK and central Europe.

Leishmaniasis in northern Syria during civil war

Via Emerging Infectious Diseases: Ahead of Print - Leishmaniasis in Northern Syria during Civil War. The abstract:

Since the onset of the ongoing civil war in Syria, the governmental surveillance system for leishmaniasis has lost access to provinces of northern Syria. The MENTOR Initiative, an international not-for-profit organization, was commissioned to implement an integrated leishmaniasis control program, providing an opportunity to reassess the epidemiology of leishmaniasis in northern Syria. 

Epidemiologic data and biologic samples for molecular species diagnostics were collected from collaborating local health centers. Incidence peaked in March 2015 at 7,743 estimated monthly cases. High levels of transmission were observed in traditional endemic regions but extended to previously hypoendemic regions, such as Al-Raqqa and Al-Hasakah. Incidence decreased to 3,209 in July 2015. 

Data indicate that the prewar trend of increasing incidence of cutaneous leishmaniasis accelerated during the beginning of armed conflict but declined after implementation of the comprehensive control program by the MENTOR Initiative. Molecular analysis revealed a spectrum of Leishmania species and sporadic cases of visceral leishmaniasis.

Pakistan: Leishmaniasis affects dozens in hilly area

Via the Pakistan Observer: Leishmaniasis affects dozens in hilly area.

Dozens of children have been affected by Leishmaniasis – a parasitic skin disease transmitted by sand-fly in different parts of hilly area Shin Ghar north of the Sherani district. The children have been suffering in Killi Kachh Kazha Mulla Nika, Killi Kamalzai and other villages of Shin Ghar in the east of Zhob city. 

The DHQ civil hospital lacks anti-leishmaniasis vaccines including other life saving drugs for the last few months that adds to the miseries of patients. 

According to Dr. Abdul Qayyum, focal person World Health Organization at Leishmaniasis center DHQ civil hospital, although the patients have approached the center, yet the center has no vaccines against the ailment that caused by the sand-fly bite.

Cutaneous leishmaniasis: A potential treatment option

In The Clinical Advisor, a letter: Cutaneous leishmaniasis: A potential treatment option.

Kudos to the cutaneous leishmaniasis case [Derm Clinics, "A painless itchy rash"]. This is a disease that will affect clinicians in the southwest US and eventually the entire country as climate warming progresses. Currently, very few providers can make the correct diagnosis, and counter to the authors' recommendation to refer the patient to a leishmaniasis expert, these experts are extremely numbered. There are treatments, but the process is complicated. The most effective treatment differs depending on the strain of leishmania contracted.  

One treatment option is amphotericin B, used originally to treat systemic fungal infections. It is also effective against mucosal leishmaniasis, but the treatment is not pleasant. It is often called “amphoterrible.” Kidney functions must be closely monitored and treatment stopped if kidney function drops below 40%.  

The authors chose not to discuss mucosal leishmaniasis in detail, which involves the parasites migrating to the mucosal tissues of the mouth and nose. Although they are often referred to as flesh-eating, the parasites do not consume tissue. Rather, the body has a profound immune response, eventually deforming and destroying the nose and mouth. There is no “cure.” This is a chronic infection, and we have yet to find a vaccination that works any better than the body's own natural responses.—Richard E. Harbin, MSN, MEd, CPNP, ARNP, Redondo Beach, Calif.

Hotez: The rise of neglected tropical diseases in the 'new Texas'

Dr. Peter Hotez, editor of PLOS Neglected Tropical Diseases, writes: The rise of neglected tropical diseases in the "new Texas". The abstract:

Within the last five years, the State of Texas has experienced either transmission or outbreaks of Ebola, chikungunya, West Nile, and Zika virus infections. Autochthonous transmission of neglected parasitic and bacterial diseases has also become increasingly reported. 

The rise of such emerging and neglected tropical diseases (NTDs) has not occurred by accident but instead reflects rapidly evolving changes and shifts in a “new” Texas beset by modern and globalizing forces that include rapid expansions in population together with urbanization and human migrations, altered transportation patterns, climate change, steeply declining vaccination rates, and a new paradigm of poverty known as “blue marble health.” 

Summarized here are the major NTDs now affecting Texas. In addition to the vector-borne viral diseases highlighted above, there also is a high level of parasitic infections, including Chagas disease, trichomoniasis, and possibly leishmaniasis and toxocariasis, as well as typhus-group rickettsiosis, a vector-borne bacterial infection. 

I also highlight some of the key shifts in emerging and neglected disease patterns, partly due to an altered and evolving economic and ecological landscape in the new Texas, and provide some preliminary disease burden estimates for the major prevalent and incident NTDs.

Scientists link new virus to leishmaniasis

Via The Hindu: Scientists link new virus to kala-azar.

Researchers have stumbled upon tantalizing evidence of an unknown virus that may be responsible for the persistence of kala-azar or visceral leishmaniasis, a parasite infection that has spawned epidemics and sickened thousands of Indians for over a century. 

It’s still early to pointedly blame the virus but its discovery portends a new kind of treatment regime and may aid attempts to eradicating the disease. 

Historically, the parasite Leishmania donovani is believed to be responsible for the dreaded infection. People get infected when bitten by an insect called the sandfly, which harbours the disease-causing parasite. 

This month, a group of scientists from West Bengal and Uttar Pradesh said that another parasite may be involved. Another parasite called Leptomonas seymouri may also be present, according to Subhajit Biswas, one of the scientists involved in the study.  

The researchers inferred this after they found the L seymouri and a virus called Lepsey NLV1 within it in 20 of 22 biological samples of patients who had a residual L donovani infection. They reported their findings in an online version of the peer-reviewed Archives of Virology.

Protection of the house against Chagas disease, dengue, leishmaniasis, and lymphatic filariasis

Via The Lancet Infectious Diseases: Protection of the house against Chagas disease, dengue, leishmaniasis, and lymphatic filariasis: a systematic review. The summary:

In light of the recent Zika virus outbreak, vector control has received renewed interest. However, which interventions are efficacious and community effective and how to best deliver them remains unclear. 

Following PRISMA guidelines, we did a systematic review to assess evidence for applied vector control interventions providing protection against Chagas disease, dengue, leishmaniasis, and lymphatic filariasis at the household level. We searched for published literature and grey literature between Jan 1, 1980, and Nov 30, 2015, and updated our search on April 2, 2017, using databases including the Cochrane, Embase, LILACS, PubMed, Web of Science, and WHOLIS. The Cochrane Collaboration's tool for assessing risk of bias was used. 

Inclusion criteria included studies reporting vector control interventions in and around a house or dwelling; and use of insecticides as sprays on netting or screens, and any method to control larval breeding in water containers in and around the home. 1416 articles were assessed and 32 articles included. 

The most effective interventions affecting vector indices for multiple diseases were found to be intradomiciliary residual spraying, insecticide-treated materials (especially insecticide-treated nets or curtains), and treatment of larval habitats with biological and chemical methods. Waste management and clean-up campaigns reduce vector populations, although to a lesser extent than other interventions and not consistently. Modifications to the structure of homes (eg, wall plastering) had no impact on the control of vectors. 

Protection of the house and its surroundings might affect the transmission of several diseases. The most effective interventions should be prioritised when vector control programmes are designed; however, the quality of delivery (ie, coverage and reapplication) of interventions is a crucial factor to ensure their effectiveness. 

Additional randomised trials that assess the measures of human disease and eventually target several diseases with a combination of interventions that protect the household and its inhabitants against multiple vectors, are needed to inform global policy in this area.

Parasite plagues subset of Iraq War veterans

Via MedPage Today: Parasite Plagues Subset of Iraq War Vets. Excerpt:

U.S. service members deployed to Iraq showed sign of having been infected with latent visceral leishmaniasis (VL) during their service, researchers said here. 

In one study, latent VL was identified in asymptomatic Operation Iraqi Freedom soldiers (10.2% of 88), potentially putting them at risk of activation of the disease if they're immunosuppressed, according to Edgie-Mark Co, DO, PhD, of the William Beaumont Army Medical Center in El Paso, Texas.  

In another study, 20 veterans with asymptomatic latent VL had no active disease, although it was not clear how likely the condition was to resurface and cause serious health problems, reported Nate Copeland, MD, of the Clinical Trials Center at Walter Reed Army Institute in Bethesda, Maryland, and colleagues. 

Both studies were presented at the annual IDWeek meeting, sponsored jointly by the Infectious Diseases Society of America (IDSA), the Pediatric Infectious Diseases Society (PIDS), the Society for Healthcare Epidemiology of America (SHEA), and the HIV Medicine Association (HIVMA). 

Leishmaniasis is spread by sand flies and is common in the Middle East. The zoonotic parasitic disease can cause chronic fever, weight loss, spleen problems, and pancytopenia. Bacterial infections, malnutrition, and severe bleeding can also occur. 

Researchers are concerned because VL, unlike the more common cutaneous form, can cause serious health problems. 

"Visceral leishmaniasis can be severe, and even life-threatening if not recognized and treated appropriately," Copeland told MedPage Today. 

He said that more than 20 cases of active VL were reported among U.S. service members in the Iraq region from 2000-2013, along with hundreds of cutaneous cases. 

The study by Co checked 88 soldiers from the El Paso area who'd served in areas with endemic VL from 2002-2011 (86% male, median age 39). Via various tests, they found that 10.2% showed signs of asymptomatic VL. 

"If you have a healthy immune system, it shouldn't be an issue. That's what your immune system does, it suppresses the disease," Co told MedPage Today. "But once you have conditions that weaken the system, that's when the disease reactivates." 

HIV, treatment with immunosuppressant drugs, and the use of steroids could put these soldiers at risk of emergence of active disease, he said.

Scientists discover role of skin in spreading leishmaniasis

Via News-Medical.net: Scientists discover role of skin in spreading leishmaniasis. Excerpt:

Scientists at the University of York have discovered that parasites responsible for leishmaniasis - a globally occurring neglected tropical disease spread by sand flies - are mainly acquired from the skin rather than a person's blood.  

Visceral leishmaniasis is a parasitic infection that kills 20-40 thousand people each year across 56 countries, mainly in the developing world. There is no vaccine and drugs are prohibitively expensive or toxic. 

Previously it was assumed that sand flies acquired the disease parasite directly from a host's blood, through biting an infected person before spreading the disease to uninfected people in subsequent bites.  

However, the number of parasites found in blood has often been puzzlingly low, leading some to question whether there is another source of parasites for transmission. 

Now, mathematicians, experimental biologists, and immunologists have revealed a 'patchy landscape of parasites' found on carriers' skin that determines how many parasites are picked up by sand flies. 

Using mathematical modeling, they showed that some areas of skin can contain particularly high numbers of the parasite, while other areas may not.  

This means that whether a sand fly becomes infected or not depends on where they bite a person.  

This breakthrough is significant as it suggests current methods of treating leishmaniasis are too simple, as disease detection and treatment often focuses on levels of the parasite in blood samples. 

The research also stresses that more attention should be focused on developing treatments that affect parasites in the skin, if the cycle of transmission is to be interrupted. 

Johannes Doehl, Post-Doctoral Research Associate in York's Centre for Immunology and Infection and lead author of the study, said: "Currently, to assess treatment success in visceral leishmaniasis, clinicians focus on monitoring parasite levels in a host's blood. 

"However, we now have conclusive proof that measuring parasites in the skin, not just the blood, is critical when assessing possible treatments. Clinical studies and elimination campaigns need to take this into account, and in particular measure how treatments affect the patchy landscape of parasites in the skin."

Venezuela and its rising vector-borne neglected diseases

An editorial in PLOS Neglected Tropical Diseases: Venezuela and its rising vector-borne neglected diseases. Excerpt:

The Bolivarian Republic of Venezuela has a population of approximately 31 million with a geographic area of approximately 350,000 square miles, about 15% and 30% larger than Texas, respectively. For decades, Venezuela was considered a leader in the areas of vector control and public health policies in the Latin American region. In fact, it is regarded as the first country to eradicate malaria in much of its territory after a successful insecticide-spraying campaign led by Arnoldo Gabaldón in the 1950s.

However, investments both in healthcare infrastructure and public health prevention efforts began to decrease during the regime of President Hugo Chavez in the 2000s, with even steeper declines beginning in 2013 with President Nicolas Maduro. According to a recent report in The Guardian, Venezuela is currently suffering an economic crisis of historical proportions with marked negative economic growth and high rates of inflation and unemployment. Food insecurity is rampant and there are serious shortages of medicines and insecticides. 

The detailed underlying basis of Venezuela’s crisis is beyond the scope of this article, but among the major factors cited are the overreliance on oil in the setting of a crash in oil prices, “reckless” public financing and printing of public money leading to an overvalued currency, massive debts and inflation, withdrawals in external investments and donor support, and public corruption. 

The political determinants of health inequity have been comprehensively reviewed by a high-level Lancet–University of Oslo Commission on Global Governance for Health. Although written before the current Venezuelan crisis, many of its findings and tenets, as described below, are relevant to the current situation. 

Overall, the rise in Venezuela’s vector-borne NTDs can be attributed to a number of factors, including (1) shortages of insecticides, antiparasitic medicines (e.g., antimalarials and drugs for leishmaniasis and Chagas disease), and fuel, which hinder vector-control and disease-treatment efforts, (2) underlying malnutrition due to food insecurity, (3) human migrations associated with illegal mining, and (4) lapses in support for government health workers. The added depletion of the health system in Venezuela due to economic and political pressures has also reduced epidemiological surveillance and reporting activities. 

Sadly, these determinants are playing out in the setting of an already unprecedented rise of arbovirus infections currently emerging across the Americas, including dengue, chikungunya, and Zika virus infections. We have also seen widespread increases in Venezuela’s vector-borne parasitic infections.