Global & Disaster Medicine

Archive for the ‘Malaria’ Category

Methylene blue & Malaria

NY Times

“……Methylene blue, a dye used to stain tissues viewed under a microscope, can be taken by tablet or injection, and is sometimes used to treat urethral infections and a hemoglobin disorder.

But the dye also kills the malaria parasites in the gametocyte stage, the point at which mosquitoes pick it up from human blood and pass it on to new victims.

Most malaria drugs do not target gametocytes, meaning that someone may still spread the disease for a week or more after treatment……”

Increase of malaria in the Americas


Following a continued decrease in the number of malaria cases from 2005 to 2014 in the Region of the Americas, an increase was observed in 2015, 2016, and most recently in 2017. In 2016, 9 countries of the Region (Colombia, Ecuador, El Salvador, Guyana, Haiti, Honduras, Nicaragua, Panama, and the Bolivarian Republic of Venezuela) reported an increase in malaria cases.

In 2017, five countries reported an increase in malaria cases: Brazil, Ecuador, Mexico, Nicaragua, and Venezuela. In addition, Cuba and Costa Rica reported indigenous cases and Honduras reported malaria cases in an area where cases had not been detected recently. Following are summaries of the malaria situation in several countries of the Region.

In Brazil, the International Health Regulations (IHR) National Focal Point reported that between January and November of 2017, there were 174,522 malaria cases reported in the Amazon region, representing an increase in comparison to the same period of 2016 when 117,832 malaria cases were reported. In 2017, the same states, with the exception of Mato Grosso, presented an increase compared to 2016 (Table 1). The states reporting the most cases were Amazonas, Pará, and Acre. In 2017, 10% (17,411 cases) of the reported malaria cases in the Amazon region, correspond to malaria due to P. falciparum and mixed infections, representing a total higher than that reported for the same period in 2015 (14,084) and in 2016 (12,366).

In Costa Rica, the Ministry of Health reported 12 indigenous cases of malaria in 2017, in the cantons of San Carlos (6 cases), Matina (3 cases), and Sarapiqui (3 cases). This represents an increase compared to 2016 when 4 indigenous cases were notified.1,2 The detection of cases in these localities highlights the risk of re-establishment of transmission in areas where ecological conditions persist.

In Ecuador, between epidemiological week (EW) 1 and EW 52 of 2017, a total of 1,279 malaria cases were reported, of these 72% correspond to P. vivax and 28% to P. falciparum.3 The number of cases reported in 2017 is higher than that reported in 2016 (926).4 The four provinces with the highest number of cases in 2017 were Morona Santiago (489), followed by Orellana (240), Pastaza (223), and Esmeraldas (215).

In Honduras, the IHR National Focal Point reported the first indigenous cases of P. vivax malaria on 30 August 2017 in the village of La Charamusca, municipality of Esquías, department of Comayagua. A total of 34 confirmed cases were reported with date of onset of symptoms between EW 27 and 37 of 2017. During the outbreak investigation, the presence of Anopheles pseudopunctipennis was reported as a vector that could be involved in the transmission. The low number of cases registered in the department of Comayagua in the last five years and the absence of transmission for several years in the affected locality, highlights the importance of maintaining surveillance and response capabilities in areas where transmission has been interrupted.

In Mexico, the Secretariat of Health notified 704 malaria cases between EW 1 to EW 50 of 2017, representing an increase from the 514 cases reported in the same period of 2016.5 The increase was particularly notable in the states of Chiapas, Chihuahua, and Tabasco, and highlighted are cases in territories without recent transmission (San Luis Potosí).

In Nicaragua, between EW 1 and EW 52 of 2017, there were 10,846 malaria cases reported, representing an increase compared to the same period in 2016 when 6,209 cases were reported.6 The majority of the cases have been reported from the North Caribbean Coast Autonomous Region.7

The Venezuela, IHR National Focal Point notified the Pan American Health Organization, Regional Office of the World Health Organization (PAHO/WHO), on 27 November 2017, that between EW 1 and EW 42 of 2017 there were 319,765 malaria cases reported between EW and EW 42 of 2017 (Figure 1); representing an increase in comparison to the accumulated reported cases in 2016 (240,613).8

Of the cases reported in 2017, 77% were due to P. vivax, 17% due to P. falciparum, 6% due to mixed infections, and <1% due to P. malariae.

The number of malaria cases reported in 2017 was higher than the annual average recorded in the past 29 years (1988-2016).9

The three states with the highest number of confirmed cases during 2017 were Bolívar (205,215), followed by Amazonas (52,471) and Sucre (45,622). The majority of municipalities in these three states are characterized as having very high and high risk of malaria transmission according to the annual parasitic incidence (API). The risk of malaria is highest in those of 20 to 39 years and account for nearly half of all the cases (47%), showing the risk related to economic activities. Of the total confirmed cases, 64% (203,956) are male and across all age groups more cases in males were reported than in females

Yemen: The World Health Organization estimated that malaria cases rose in 2016 to 433,000 from 336,000 the year before.


Map of Malaria endemic areas in the world.


The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells and mature into schizonts , which rupture and release merozoites . (Of note, in P. vivax and P. ovale a dormant stage [hypnozoites] can persist in the liver and cause relapses by invading the bloodstream weeks, or even years later.) After this initial replication in the liver (exo-erythrocytic schizogony ), the parasites undergo asexual multiplication in the erythrocytes (erythrocytic schizogony ). Merozoites infect red blood cells . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites . Some parasites differentiate into sexual erythrocytic stages (gametocytes) . Blood stage parasites are responsible for the clinical manifestations of the disease.

The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal . The parasites’ multiplication in the mosquito is known as the sporogonic cycle . While in the mosquito’s stomach, the microgametes penetrate the macrogametes generating zygotes . The zygotes in turn become motile and elongated (ookinetes) which invade the midgut wall of the mosquito where they develop into oocysts . The oocysts grow, rupture, and release sporozoites , which make their way to the mosquito’s salivary glands. Inoculation of the sporozoites into a new human host perpetuates the malaria life cycle.

Treatment of Malaria: Guidelines For Clinicians (United States)


Malaria can be a severe, potentially fatal disease (especially when caused by Plasmodium falciparum) and treatment should be initiated as soon as possible.

Patients who have severe P. falciparum malaria or who cannot take oral medications should be given the treatment by continuous intravenous infusion.

Most drugs used in treatment are active against the parasite forms in the blood (the form that causes disease) and include:

  • chloroquine
  • atovaquone-proguanil (Malarone®)
  • artemether-lumefantrine (Coartem®)
  • mefloquine (Lariam®)
  • quinine
  • quinidine
  • doxycycline (used in combination with quinine)
  • clindamycin (used in combination with quinine)
  • artesunate (not licensed for use in the United States, but available through the CDC malaria hotline)

In addition, primaquine is active against the dormant parasite liver forms (hypnozoites) and prevents relapses. Primaquine should not be taken by pregnant women or by people who are deficient in G6PD (glucose-6-phosphate dehydrogenase). Patients should not take primaquine until a screening test has excluded G6PD deficiency.

How to treat a patient with malaria depends on:

  • The type (species) of the infecting parasite
  • The area where the infection was acquired and its drug-resistance status
  • The clinical status of the patient
  • Any accompanying illness or condition
  • Pregnancy
  • Drug allergies, or other medications taken by the patient

Report a serious drug side effect

If you have had a serious side effect while taking a drug, you or your health care provider can report that side effect to the federal Food and Drug Administration (FDA). MedWatch is the FDA Safety Information and Adverse Event Reporting Program. You are encouraged to take the reporting form to your health care provider.

Alternatively, health care providers can report to the FDA.

The advantage to having your health care provider file the report is that he/she can provide clinical information based on your medical record that can help the FDA evaluate the report.

However, for a variety of reasons, you may not wish to have the form completed by your provider, or the provider may not wish to complete the form. Your health care provider is not required to report to the FDA. In this case, you may complete the online reporting form at yourself via the Internet.

Related Links

The CDC malaria diagnosis and treatment guidelines have also been published in an article in JAMA May 23, 2007 and can be accessed for free online: view JAMA article.

Malaria outbreak spreads in drug-short Venezuela


“…..The government has not given an overall death toll. But health
activists and doctor groups estimate that around 200 people have died
from malaria over the last year [2016] nationwide, and fear the
illness is starting to afflict populated urban centers…….

The regional arm of the World Health Organization last month [October
2017] announced the arrival of over one million anti-malarial pills,
which doctors deem insufficient. Patients must visit their nearest
health center up to 4 times to complete treatment in what officials
say is an attempt to avoid feeding the black market for drugs……”



EPA Registers the Wolbachia ZAP Strain in Live Male Asian Tiger Mosquitoes in order to reduce their population thereby reducing the spread numerous diseases of significant human health concern



 For Release:  November 7, 2017

On November 3, 2017, EPA registered a new mosquito biopesticide – ZAP Males® – that can reduce local populations of the type of mosquito (Aedes albopictus, or Asian Tiger Mosquitoes) that can spread numerous diseases of significant human health concern, including the Zika virus.

ZAP Males® are live male mosquitoes that are infected with the ZAP strain, a particular strain of the Wolbachia bacterium. Infected males mate with females, which then produce offspring that do not survive. (Male mosquitoes do not bite people.) With continued releases of the ZAP Males®, local Aedes albopictus populations decrease. Wolbachia are naturally occurring bacteria commonly found in most insect species.

This time-limited registration allows MosquitoMate, Inc. to sell the Wolbachia-infected male mosquitoes for five years in the District of Columbia and the following states: California, Connecticut, Delaware, Illinois, Indiana, Kentucky, Massachusetts, Maine, Maryland, Missouri, New Hampshire, New Jersey, Nevada, New York, Ohio, Pennsylvania, Rhode Island, Tennessee, Vermont, and West Virginia. Before the ZAP Males® can be used in each of those jurisdictions, it must be registered in the state or district.

When the five-year time limit ends, the registration will expire unless the registrant requests further action from EPA.

EPA’s risk assessments, along with the pesticide labeling, EPA’s response to public comments on the Notice of Receipt, and the proposed registration decision, can be found on under docket number EPA-HQ-OPP-2016-0205.

How much has malaria declined in the Americas?

Italy: 4 cases of locally transmitted P. falciparum malaria


Malaria Outbreak in Ginosa, Italy

On October 3, 2017, Italy reported four cases of locally transmitted P. falciparum malaria among migrant agricultural workers in Ginosa, which is in the Taranto Province of the Apulia region of Italy. The four patients were males, between 21–37 years of age, and lived in camps with other migrant workers in the Ginosa area. Three of the patients were from Morocco where there is no malaria, and one is from Sudan which is a malaria-endemic country. All reported no travel for the past two months. Italian public health authorities continue to investigate this outbreak.

Italy was declared free of malaria by the World Health Organization in 1970. However, the mosquitoes that transmit malaria, specifically Anopheles labrachiae, An. manulipennis, An. superpictus, and possibly An. sacharovi, are present. Thus, rare autochthonous cases have been reported including P. vivax in Tuscany in 1997 and P. vivax in Latina Province in 2009.

Given the focal, limited nature of this outbreak so far, CDC recommends only mosquito avoidance measures for travelers to agricultural areas of Ginosa. These measures include using insect repellent when outdoors, staying in an air-conditioned or well-screened area, and sleeping under an insecticide-treated bed net. CDC will continue to monitor the malaria situation in Italy and will update these recommendations as needed.

See the CDC malaria website for additional health information about malaria, including prevention of mosquito bites and drugs for malaria prevention. For general health information for travelers to all areas of the world, see the CDC Travelers’ Health website.

After five long years, malaria is back with a vengeance in Delhi and the number of cases has shot up alarmingly to 113


Picture of a woman taking malaria pills


WHO: New vector control response seen as game-changer


The call came from the WHO Director-General in May 2016 for a renewed attack on the global spread of vector-borne diseases.

“What we are seeing now looks more and more like a dramatic resurgence of the threat from emerging and re-emerging infectious diseases,” Dr Margaret Chan told Member States at the Sixty-ninth World Health Assembly. “The world is not prepared to cope.”

Dr Chan noted that the spread of Zika virus disease, the resurgence of dengue, and the emerging threat from chikungunya were the result of weak mosquito control policies from the 1970s. It was during that decade that funding and efforts for vector control were greatly reduced.

‘Vector control has not been a priority’

Dr Ana Carolina Silva Santelli has witnessed this first-hand. As former head of the programme for malaria, dengue, Zika and chikungunya with Brazil’s Ministry of Health, she saw vector-control efforts wane over her 13 years there. Equipment such as spraying machines, supplies such as insecticides and personnel such as entomologists were not replaced as needed. “Vector control has not been a priority,” she said.

Today more than 80% of the world’s population is at risk of vector-borne disease, with half at risk of two or more diseases. Mosquitoes can transmit, among other diseases, malaria, lymphatic filariasis, Japanese encephalitis and West Nile; flies can transmit onchocerciasis, leishmaniasis and human African trypanosomiasis (sleeping sickness); and bugs or ticks can transmit Chagas disease, Lyme disease and encephalitis.

Together, the major vector-borne diseases kill more than 700 000 people each year, with populations in poverty-stricken tropical and subtropical areas at highest risk. Other vector-borne diseases, such as tick-borne encephalitis, are of increasing concern in temperate regions.

Rapid unplanned urbanization, massive increases in international travel and trade, altered agricultural practices and other environmental changes are fuelling the spread of vectors worldwide, putting more and more people at risk. Malnourished people and those with weakened immunity are especially susceptible.

A new approach

Over the past year, WHO has spearheaded a new strategic approach to reprioritize vector control. The Global Malaria Programme and the Department of Control of Neglected Tropical Diseases – along with the Special Programme for Research and Training in Tropical Diseases, have led a broad consultation tapping into the experience of ministries of health and technical experts. The process was steered by a group of eminent scientists and public health experts led by Dr Santelli and Professor Thomas Scott from the Department of Entomology and Nematology at the University of California, Davis and resulted in the Global Vector Control Response (GVCR) 2017–2030.

At its Seventieth session, the World Health Assembly unanimously welcomed the proposed response.

The GVCR outlines key areas of activity that will radically change the control of vector-borne diseases:

  • Aligning action across sectors, since vector control is more than just spraying insecticides or delivering nets. That might mean ministries of health working with city planners to eradicate breeding sites used by mosquitoes;
  • Engaging and mobilizing communities to protect themselves and build resilience against future disease outbreaks;
  • Enhancing surveillance to trigger early responses to increases in disease or vector populations, and to identify when and why interventions are not working as expected; and
  • Scaling-up vector-control tools and using them in combination to maximize impact on disease while minimizing impact on the environment.

Specifically, the new integrated approach calls for national programmes to be realigned so that public health workers can focus on the complete spectrum of relevant vectors and thereby control all of the diseases they cause.

Recognizing that efforts must be adapted to local needs and sustained, the success of the response will depend on the ability of countries to strengthen their vector-control programmes with financial resources and staff.

A call to pursue novel interventions aggressively

The GVCR also calls for the aggressive pursuit of promising novel interventions such as devising new insecticides; creating spatial repellents and odour-baited traps; improving house screening; pursuing development of a common bacterium that stops viruses from replicating inside mosquitoes; and modifying the genes of male mosquitoes so that their offspring die early.

Economic development also brings solutions. “If people lived in houses that had solid floors and windows with screens or air conditioning, they wouldn’t need a bednet,” said Professor Scott. “So, by improving people’s standard of living, we would significantly reduce these diseases.”

An entomologist inserts live mosquitoes in wall of a mud house in Kisumu, Kenya

An entomologist inserts live mosquitoes into a standard ‘cone bioassay’. After 30 minutes he will see how many have been killed – this will measure if the insecticide was sprayed properly on the walls, and constitutes intervention monitoring.
WHO/S. Torfinn

The call for a more coherent and holistic approach to vector control does not diminish the considerable advances made against individual vector-borne diseases.

Malaria is a prime example. Over the past 15 years, its incidence in sub-Saharan Africa has been cut by 45% – primarily due to the massive use of insecticide-treated bed nets and spraying of residual insecticides inside houses.

But that success has had a down side.

“We’ve been so successful, in some ways, with our control that we reduced the number of public health entomologists – the people who can do this stuff well,” said Professor Steve Lindsay, a public health entomologist at Durham University in Britain. “We’re a disappearing breed.”

The GVCR calls for countries to invest in a vector-control workforce trained in public health entomology and empowered in health care responses.

“We now need more nuanced control – not one-size-fits-all, but to tailor control to local conditions,” Professor Lindsay said. This is needed to tackle new and emerging diseases, but also to push towards elimination of others such as malaria, he said.

Dr Lindsay noted that, under the new strategic approach, individual diseases such as Zika, dengue and chikungunya will no longer be considered as separate threats. “What this represents is not three different diseases, but one mosquito – Aedes aegypti,” said Professor Lindsay.

GVCR dovetails with Sustainable Development Goals

The GVCR will also help countries achieve at least 6 of the 17 Sustainable Development Goals. Of direct relevance are goal 3 on good health and well-being, goal 6 on clean water and sanitation, and goal 11 on sustainable cities and communities.

The GVCR goals are ambitious – to reduce mortality from vector-borne diseases by at least 75% and incidence by at least 60% by 2030 – and to prevent epidemics in all countries.

The annual price tag is US$ 330 million globally, or about 5 cents per person – for workforce, coordination and surveillance costs. This is a modest additional investment in relation to insecticide-treated nets, indoor sprays and community-based activities, which usually exceed US$ 1 per person protected per year.

It also represents less than 10% of what is currently spent each year on strategies to control vectors that spread malaria, dengue and Chagas disease alone. Ultimately, the shift in focus to integrated and locally adapted vector control will save money.

‘A call for action’

Dr Santelli expressed optimism that the GVCR will help ministries of health around the world gain support from their governments for a renewed focus on vector control.

“Most of all, this document is a call for action,” said Dr Santelli, who now serves as deputy director for epidemiology in the Brasilia office of the U.S. Centers for Disease Control and Prevention.

It will not be easy, she predicts. The work to integrate vector-control efforts across different diseases will require more equipment, more people and more money as well as a change in mentality. “The risk of inaction is greater,” said Dr Santelli, “given the growing number of emerging disease threats.” The potential impact of the GVCR is immense: to put in place new strategies that will reduce overall burden and, in some places, even eliminate these diseases once and for all.


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