TropIKA Blog Portal

Modellers say Haiti's cholera will be worse than predicted

Using a computerised model to estimate the size of the cholera burden in Haiti this year, US researchers have concluded that, in the absence of new interventions, there will be nearly 800,000 cases with more than 11,000 deaths [1]. The figures are substantially higher than those proposed by UN agencies. The model also shows that a recent decline in cases of cholera is not the result of successful interventions currently being employed, but rather the natural course of the epidemic. The researchers say that a combination of clean water provision, vaccination, and expanded access to antibiotics might avert thousands of deaths. The findings are discussed further in a Lancet Comment and Podcast. (See also BBC news story.) Reference 1. Andrews JR, Basu S (2011). Transmission dynamics and control of cholera in Haiti: an epidemic model. Lancet: http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2811%2960273-0/fulltext

Researchers develop rapid test to detect cholera

There are an estimated 3-5 million cholera cases, and 100,000-120,000 deaths worldwide each year, according to the World Health Organization, and major epidemics, such as those in Haiti and in Zimbabwe demonstrate the scale of the problem. The disease can be avoided if communities are supplied with clean water and sanitation. But water sources that were once reliable can become contaminated with the cholera toxin in disaster situations (such as Haiti) or when public infrastructure is neglected (Zimbabwe). A rapid test to determine whether water supplies are contaminated with cholera has been developed by researchers at the University of Central Florida (UCF). In the test, a sugar (dextran) is coated on to iron oxide nanoparticles and then added to a sample of the water. If the cholera toxin is present, the toxin will bind to the nanoparticles’ dextran. This is because dextran looks similar to the cholera toxin receptor (GM1) found on cells' surface in the victim's gut. The research team believe that their technique is likely to be less expensive than those currently available, and it would provide results more quickly, enabling workers to restrict access to contaminated sources and limit the spread of the disease. Further details in UCF press release.

Haiti's cholera: why is it so bad?

Cholera epidemics are sadly now commonplace; West Africa and Papua New Guinea are amongst the areas now experiencing problems. Although Haiti had not seen cholera for half a century, it should not come as a surprise that, following the disruption caused by the earthquake and by storm damage, it is also now experiencing a major outbreak. But two questions need to be answered - why has the epidemic struck with such force (there have been some 57,000 cases and nearly 1,500 deaths) and what happens next? The prevailing view (see recent SciDev.Net article) seems to be that the severity of the epidemic has resulted from a tragic coincidence - the post-earthquake decline in water and sanitation standards occurred at the same time as climatic changes caused by the ocean-atmosphere phenomenon La Niña. It is believed that cholera was already present, though undetected, in the country and the combination of new factors made possible its explosive spread. This goes against the view, widely held by Haitians, that UN soldiers from Nepal, where cholera is endemic, brought the infection with them. (The strain identified in Haiti does in fact most closely resemble Asian strains.) As for what happens next, if the scientists SciDev.Net spoke to are correct, then the epidemic should start to weaken now that the waters of the Caribbean are cooling down. But the Pan American Health Organization believes that many more cases are on the way - the total could reach 20,000 during the next three months and 400,000 within the next year. PAHO has stressed the need for adequate supplies and personnel to deal with the continuing epidemic. The organization's deputy director, Jon Kim Andrus, reported by AFP, also expressed concern that neighbouring countries could be affected: "For many of us, this brings to mind the cholera epidemic that began in Peru in 1991 and spread to more than 16 other countries in the Americas within two years".

West Africa's cholera spreads

The cholera Africa that began earlier this year in Nigeria and Cameroon is continuing to spread. Niger and Chad are also now affected. There have been over 40,000 cases and an estimated 1900 deaths, 1200 of them in Nigeria (see ReliefWeb). The epidemic is said to be the worst experienced in the region for over 20 years. Flooding in some areas has encouraged the spread of the disease. Inadequate surveillance and poor diagnostics have been blamed for the failure to stem its spread (see IRIN News). WHO and MSF are amongst the agencies providing support to health services in the afflicted areas.

A "manifesto" for combatting NTDs

Despite evidence that the global burden of neglected diseases is as great as that of any other serious disease, financial support for elimination efforts and R&D has been inadequate, say the authors of a new "Manifesto for Advancing the Control and Elimination of Neglected Tropical Diseases", published this week. Writing in PLoS Neglected Tropical Diseases, Peter Hotez, President of the Sabin Vaccine Institute and Distinguished Research Professor of The George Washington University Medical Center, and Bernard Pecoul, Executive Director of Drugs for Neglected Diseases initiative (DNDi), outline in eight points why the global community should increase financial support for NTD control and elimination efforts and research and development. The manifesto states that:

· All NTDs are "tool ready" with cost-efficient and effective interventions that could be implemented now, even if for some diseases such tools are far from being perfect or complete.

· At the same time that NTDs are tool ready they are also tool deficient, signifying that the tools are incomplete, or inadequate, to sustain elimination efforts.

· NTDs have received little attention from the international community during the past ten years despite their large disease burden.

· Increasing evidence indicates an association between NTD prevalence and conflict and violation of human rights.

· NTDs can be particularly destabilizing and disrupt agricultural productivity and food security. Many poor societies with high NTD burdens have been recently engaged in a civil or international conflict or are currently at war.

· Sustained involvement by the WHO and other international health agencies is crucial for current and future NTD control and elimination efforts.

· Nothing is more important to the success of global NTD control than the involvement of communities themselves and disease-endemic countries' health ministries.

· Achievement of Millennium Development Goal 8 ("develop a global partnership for development") will rest with stakeholders — health ministries, affected communities, public–private partnerships, large and small non-governmental organizations, etc. — establishing a well-functioning international strategy for NTD control.

While acknowledging that policymakers are “slowly beginning to appreciate the importance of NTDs” — evidenced by the creation of a new department of Neglected Tropical Diseases at the World Health Organization; TDR’s 10-year strategic plan; and the identification, by NIH’s Francis Collins, of neglected diseases as a research priority, among other developments — Hotez and Pecoul argue that the challenge of NTDs calls for a manifesto — “a public declaration of motives by a government or by a person or group regarded as having some public importance.”

Moreover, they add, by doing more to tackle NTDs, the global health community can make progress toward Millennium Development Goals.

"[NTD control] activities have facilitated the delivery of additional interventions such as insecticide-treated bed nets, antimalarial drugs, micronutrients, and childhood immunizations," they write.

The authors urge scientists working on NTDs to increase collaboration and identify funding opportunities and cost-efficient interventions.

"By highlighting important challenges in the fight against NTDs, this 'manifesto' calls on the global community for urgent, renewed, and innovative efforts."

Filtration of water through saris retains popularity

The most effective way of preventing cholera is through the provision of safe water supplies. But what can families with no access to safe water do to reduce their risk of infection? Research conducted in Bangladesh in 2003 [1] concluded that, when some 70,000 village women responsible for collecting water were taught to filter it through folded cotton sari cloth, the incidence of cholera was halved. There were concerns that the women might not continue with the practice in the longer term. A follow-up study [2] now reports that, five years later, 31% of the women continued to filter their water, of whom 60% used a sari. Additionally, the researchers found that 26% of women in a control group, who did not receive any education or training in the first study, also filtered their water. Filtration has clearly impressed not only many of the women who were trained but also a good number of their neighbours. Nevertheless, it is clear that without a continuing programme to promote the use of 'sari filtration', many women will abandon the practice. The researchers looked at the incidence of cholera in households during the five-year follow-up period; the incidence of hospitalizations for cholera during the period reduced by 25% but this decline was not statistically significant. The mechanism through which sari cloth seems to filter out Vibrio cholerae bacteria is likely to depend on the removal of particulate matter and zooplankton with which V. cholerae is associated. The follow-up study appears in mBio, a new open access online journal published by the American Society for Microbiology. A summary also appears on the Society's website. Reference 1. Colwell R, Huq A, Islam M, Aziz K, Yunus M, Khan N, Mahmud A, Sack R, Nair G, Chakraborti J, Sack D, Russek-Cohen E (2003). Reduction of cholera in Bangladesh villages by simple filtration. Proc Natl Acad Sci USA; 100:1051-1055. 2. Huq A, Yunus M, Sohel SS, Bhuiya A, Emch M, Luby S, Russek-Cohen E, Nair B, Sack RB, Colwell R (2010). Simple Sari Cloth Filtration of Water Is Sustainable and Continues To Protect Villagers from Cholera in Matlab, Bangladesh. mBio; 1(1):e00034-10. Available from: http://mbio.asm.org/content/1/1/e00034-10.full?sid=fa50f8ec-e969-40b1-b30e-4c2710039a72

Neglected tropical diseases: debating the best way forward

An article [1] in PLoS Medicine's Debate series examines the different approaches that can be taken to tackle neglected tropical diseases (NTDs). Some commentators, such as Jerry Spiegel and colleagues from the University of British Columbia, feel there has been too much focus on the biomedical mechanisms and drug development for NTDs, at the expense of attention to the social determinants of disease. Burton Singer argues that this represents another example of the inappropriate “overmedicalization” of contemporary tropical disease control. Peter Hotez and colleagues, in contrast, argue that the best return on investment will continue to be mass drug administration for NTDs. Reference 1. Spiegel JM, Dharamsi S, Wasan KM, Yassi A, Singer B, et al. (2010) Which New Approaches to Tackling Neglected Tropical Diseases Show Promise? PLoS Med 7(5): e1000255. Available from: http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pmed.1000255

Bangladesh's success against diarrhoea

A recent article in USA Today looks at Bangladesh's success over the past 30 years in combatting diarrhoeal diseases using the so-called "Poor man's Gatorade," a homemade concoction of salt, sugar and water that led to the development, in the late 1960s, of oral rehydration solution (ORS). In 1971, during a cholera outbreak in West Bengal among refugees of the Bangladesh "War of Liberation", ORS proved itself a highly effective intervention, slashing the death rate from 50% to 3% of those infected. The article discusses the International Centre for Diarrhoeal Diseases Research (ICDDR,B) located in Dhaka, Bangladesh. Founded in 1978, ICDDR,B has trained more than 27,000 health professionals from more than 78 countries in the control of diarrhoeal diseases, epidemiology, biostatistics, family planning, demographic surveillance and child survival strategies. Current ICDDR,B projects encompass a broad range of issues, including child health and nutrition, HIV/AIDS and chronic and infectious diseases. In collaboration with Massachusetts General Hospital (MGH) in the US, ICDDR,B clinical researchers are investigating the differences between naturally-acquired immunity from infection with cholera and immunity conferred by vaccination in the hopes that findings will lead to a vaccine protective for longer than those currently on the market. A recent article in Mass General Magazine describes the collaborative effort in detail, tracing it from its origins in the mid-1990s to the present day.

Papua New Guinea makes progress against cholera

Many countries have experienced serious cholera outbreaks in the last few years. The appearance of the disease in Papua New Guinea (PNG) in August 2009 has been of particular interest, as it was previously unknown in this Pacific nation; reports have described instances of public panic and of stigma against cholera patients. Now, however, IRIN News says that the outbreak appears to be almost over, after nearly 3,000 cases and 60 deaths. Victor Golpak, the government’s national response coordinator for cholera says that only a few cases are now being seen each week. He noted the importance of the assistance provided by international agencies in bringing the disease under control. Nevertheless, 58% of PNG’s six million inhabitants still lack access to safe drinking water and experts have cautioned that until this situation is addressed the country will be at risk of further outbreaks.

Indian cholera vaccine to be available soon

India's Department of Biotechnology (DBT) has invited applications to commercialise a new oral vaccine for cholera, according to the Vaccine India website. The vaccine has been developed by the Institute for Microbial Technology, Chandigarh, and National Institute of Cholera and Enteric Diseases, Kolkata. Phase III trials of the vaccine are planned and the DBT believes that it could be available for use before the end of 2010.

Cholera surveillance will be improved in Africa

The last two years have seen outbreaks of cholera in many parts of Africa but surveillance systems for the disease there nevertheless remain poor. French organization Agence de Medecine Preventive (AMP) has received a three-year grant of $4.9 million from the Bill & Melinda Gates Foundation to create a consortium that will establish an African Cholera Surveillance Network (AFRICHOL) to strengthen cholera surveillance and outbreak response in at least eight African countries. AMP and the African Field Epidemiology Network (AFENET) will be the core members of the consortium, which will also include several other leading health organizations from around the world. AMP will expand cholera surveillance by actively mobilizing regional and international organizations. AFENET will be responsible for overseeing project implementation in several countries. "AMP will rely on its extensive global network to bring to the table the most important organizations working on cholera prevention in resource-poor settings," said Alfred da Silva, executive director of AMP. "It is only through such a collective effort that we will be able to establish the true burden of disease in sub-Saharan Africa." Further details are available in an AMP press release. APM has also recently received a Gates grant to improve advocacy for vaccines and immunization systems in West Africa (press release). Agence de Medecine Preventive The Agency for Preventive Medicine is a nonprofit organization that aims to improve the quality of health service delivery in developing countries. It describes its mission as follows: • to contribute to the analysis of the health problems of developing countries through operational and scientific research • to participate in scientific and technical programmes based on the results of action research • to collaborate with developing countries, research institutions and international organizations for effective implementation of recommendations • to strengthening country capacity in health activities for the population, particularly mothers and children.

Deep Springs International works to provide clean water in Haiti

Three days after an earthquake struck Haiti, time is running out for survivors desperate for food and clean drinking water. While rescue teams are now arriving on the scene, aid efforts have largely faltered and major shipments of water and food have been unable to reach those in greatest need. As survivors succumb to thirst and dehydration, they'll likely turn to water distribution systems that have been compromised by the damage to infrastructure and the lack of sanitation in crowded camps. That can lead to massive outbreaks of water-borne diseases like cholera, a disease capable of ravaging refugee camps in a matter of hours. In the wake of the 1994 Rwandan genocide, for example, cholera killed some 45,000 people in less than three weeks. Among the organizations responding to the crisis is the Haiti-based Deep Springs International (DSI). In collaboration with the US Centers for Disease Control and Prevention (CDC), DSI is working to develop an immediate implementation plan to respond to the country's myriad clean water needs. DSI President and in-country director, Michael Ritter is based in Baudin, 30 miles southwest of Port-au-Prince, and is in contact with CDC's Daniele Lantagne, a leading expert in diarrheal diseases. To learn more about what Deep Springs International does, visit their site. Updates will follow as they become available.

US charity steps up its programme on neglected infections

A news report highlights the activities of Medical Assistance Programs International (MAP) a US Christian group which is supplying drugs for the treatment of neglected infectious diseases in developing countries. Drugs worth $400 million were dispatched last year alone. The group is also involved in community health programmes. The group plans to step up its activities against neglected infections, including Chagas disease, Buruli ulcer, cholera, dengue fever, sleeping sickness, lymphatic filariasis, trachoma and soil-transmitted helminths. Information is also available on the MAP International website.

Cholera death toll rises in Kenya

For some months parts of Kenya have been facing a cholera epidemic. An outbreak that has caused at least eleven deaths has now hit a slum area of the capital, Nairobi. The Daily Nation says hundreds of people have been seeking treatment. Tests are still being conducted to confirm that the disease is indeed cholera. Health promotion activities on cholera are also being stepped up in the Mukuru Kwa Njenga slum. Other reports say that unlicensed water sellers are being blamed for spreading the infection. The slum is served by several companies which supply water from tankers. According to a report from Edie (Environmental Data Interactive Exchange), "While selling water is a tightly-regulated business in the city, with vendors required to apply for permits from the Nairobi City Water and Sewerage Company (NCWSC), many sidestep the rules as there is a market for cheaper, untested water". The Daily Nation says there have been nearly 4,000 cases and some 120 deaths from cholera since the epidemic began in December last year.

Cholera and climate

Poverty and poor water and sanitation are the main factors responsible for cholera epidemics. However, the recent increase in case numbers in many countries may also be linked to global warming and the El Niño (the warm phase of the periodic change in the atmosphere and ocean of the tropical Pacific region). A report from IRIN notes that 2009, an El Niño year, has seen the first recorded cases of cholera in Papua New Guinea, in addition to serious epidemics in Africa. (During the 1997-98 El Niño, a rise in sea surface temperature coupled with excessive flooding emerged as two significant factors in cholera epidemics in Bangladesh, Djibouti, Somalia, Kenya, Tanzania, and Mozambique.) The IRIN article includes comments from several climate specialists includung US scientist Rita Colwell, who says: "My hypothesis, which we are in the process of testing, is that climate changes (sea surface temperature, sea surface height, rainfall, etc.) have influenced the cholera epidemics in East Africa, notably Mozambique." She stresses that deterioration in the water purification and delivery in Zimbabwe was the main factor responsible for that country's massive cholera outbreak but she believes that climate changes also had an influence. An increasing number of studies are supporting the notion of a climate-cholera link. However, we must guard against any suggestion to the effect that "It's all down to the climate, so there's nothing we can do". Poverty reduction efforts and water and sanitation projects must not be weakened. Dengue fever is another disease with a climate change link and here too it must be remembered that a bigger role is played by other factors, such as increased urbanisation and inadequate mosquito control.

Stigma hampers cholera control efforts in Papua New Guinea

Victims of infectious conditions often suffer prejudice from those around them. This stigma can seriously hamper disease control efforts. Cholera is not a disease particularly associated with stigma but, according to a report from IRIN, recovered cholera patients in Papua New Guinea have returned home to find themselves shunned by their neighbours. There have also been disturbing reports of people dying at the side of the road, because no one was willing to take them to hospital. The country is currently dealing with a serious epidemic of cholera, but it appears to be first time that the disease has occurred there. Fear of a previously unknown threat is probably the root cause of the stigma that patients are encountering. Efforts are being made by aid workers, WHO staff and others in Papua New Guinea to improve awareness and understanding of cholera.

Infections rise as East African drought takes its toll

The serious continuing drought in East Africa has caught the attention of the international media. Northern Kenya has been severely affected. A report from IRIN reminds us of the capability of infectious diseases to take advantage of such natural disasters. The news agency says that increases in cholera, polio and measles in drought-afflicted parts of Kenya are causing considerable concern.

Cholera: some good news from Angola

Southern Africa has been seriously hit by cholera this year, with Zimbabwe the worst afflicted nation. It is therefore encouraging to read, in an AFP report, that one country in the region (Angola) has seen a decline in case numbers. In the first five months of 2008, WHO detected 7,740 cases of cholera with 198 fatalities in Angola. But in the same period this year,there have been only 681 recorded cases and three deaths. Only five of Angola's 18 provinces have been affected. WHO has credited the fall in cholera incidence to community education and improved sanitation.

How do we control diarrhoeal disease: better treatment, vaccination or improved water and sanitation?

Back in the 1980s, diarrhoeal diseases were seen as one of the main targets of global health activities. The promotion of oral rehydration therapy was close to the top of all the priority lists. Remarkably, since then, these diseases, still the second biggest infectious killer of poor children (after lower respiratory tract infection), have now entered the 'neglected' category. TropIKA.net has recently highlighted a report intended to spearhead a campaign to restore diarrhoeal diseases back to priority status but the question remains as to how the burden of these diseases can be reduced. Some see the way forward as being effective vaccines for cholera, rotavirus, Shigella and other organisms. Others point out that if people had access to safe water and decent sanitation then they would not get diarrhoea in the first place. Meanwhile, efforts are also being made to find new treatment drugs - see TropIKA.net news. All of these interventions have a part to play. In an interview with IRIN, John Clemens of the International Vaccine Institute (IVI)says that: “Introducing a cheaper vaccine in endemic countries does not mean diminishing the importance of safe water access. It is a false dichotomy to pit sanitation against vaccination. Improved water and sanitation is the ultimate, but still far-off, goal for impoverished [endemic] countries.” Successful poverty reduction, water and sanitation programmes would considerably reduce the need for vaccines, which would perhaps be unnecessary in an ideal world. However, the pragmatic approach must be to include vaccine (and drug) research in comprehensive programmes to reduce diarrhoeal morbidity and mortality. But to the list - of poverty reduction, water, sanitation, vaccines and drugs - we must also add the need for effective health systems. The collapse of Zimbabwe's health services, for example, continues to be a major factor in the failure to halt the spread of cholera there. An investigation into the handling of the Zimbabwean epidemic also found over-reliance on intravenous fluids and inadequate use of oral rehydration therapy. ORT promotion must be restored to the priority list.

Climate change and the economy: increase in infectious diseases will add to the problems

"The Economics of Climate Change in Southeast Asia: A Regional Review" is a major new report from the Asian Development Bank. It is based on the results of a 15-month study, funded by the UK, which examined climate change issues in Southeast Asia, with a particular focus on Indonesia, Philippines, Singapore, Thailand, and Vietnam. The report says that: "The study observed that climate change is already affecting Southeast Asia, with rising temperature, decreasing rainfall, rising sea levels, increasing frequency and intensity of extreme weather events leading to massive flooding, landslides and drought causing extensive damage to property, assets, and human life. Climate change is also exacerbating the problem of water stress, affecting agriculture production, causing orest fires, degrading forests, damaging coastal marine resources, and increasing outbreaks of infectious diseases." Health In the report's section on human health, the startling rise in the incidence of dengue in the region, with many previously unaffected areas now reporting cases, is regarded as being of particular concern. Further increases in temperature could lead to a worsening of the position for other vector-borne infections such as malaria. Diarrhoeal disease, including cholera, is also considered likely to increase. The report concludes that: "An increase in morbidity and mortality is predicted to occur in most Southeast Asian countries due to water-borne diseases, primarily associated with floods and droughts." Other likely impacts on human health range from malnutrition to thermal stress. Despite these concerns and the potential economic impact resulting from the damage to health, agriculture and natural resources, the Asian Development Bank considers there is a positive side. Bank Vice-President Ursula Schaefer-Preuss says: "The global economic crisis provides an opportunity for the world, and Southeast Asia, to start the transition toward a climate-resilient and low-carbon economy."

Heat, rain and cholera: Zambian study examines the associations

How are climate change and infectious disease incidence related and is global warming leading to increased rates of certain infections? The question is often asked but reliable data on the issue are in short supply. A new study [1] based on research, carried out in Lusaka (Zambia) between 2003 and 2006, analyses data from three cholera epidemics which occurred in a consecutive fashion. The results appear to show that climatic variables (rainfall and environmental temperature) are associated with the number of cholera cases. There is a known to be a seasonal element to cholera in Zambia, which is associated with the rainy season. In the study - led by researchers from the Madrid Carlos III Institute of Health, Madrid - environmental temperatures were recorded six weeks before the beginning of the rains. The authors claim to have showed that a 1º C increase in temperature six weeks before the beginning of an outbreak is associated with a 5.2% increase in cholera cases. Looking at rainfall, they found that, if a 50 millimetre rise in precipitation three weeks later is added to this increase it is associated with a 2.5% increase in risk. The authors say that with further research it could be possible to predict the likely severity of outbreaks, which would be of assistance in epidemic preparedness. (A summary of the study is available on Science Daily.) Reference 1. Miguel Ángel Luque Fernández, Ariane Bauernfein, Julio Díaz Jiménez, Cristina Linares Gil, Nathalie El Omeiria, Dionisio Herrera Guibert (2009). Influence of temperature and rainfall on the evolution of cholera epidemics in Lusaka, Zambia, 2003-2006: analysis of a time series. Transactions of the Royal Society of Tropical Medicine and Hygiene; 103(2).

Progress in Mozambique is marred by cholera

The current cholera epidemic in Africa is producing some worrying statistics ...and news headlines. Mozambique for example has released new figures showing that, since the start of this year, over 13,000 Mozambicans have been diagnosed with the disease, compared with about 12,000 for all of 2008. There have been 140 deaths so far this year; there were 150 in the whole of 2008. Mozambique has a long border with Zimbabwe, which currently has the most severe cholera problem and has become a major exporter of the disease. However, Mozambique has progress to report as regards other infectious diseases of poverty. Leprosy is no longer regarded as a public health problem in the country. In 2008, all provinces in Mozambique recorded less than one case of leprosy per 10,000 inhabitants. Measles vaccination campaigns have led to a dramatic reduction in notified cases, by over 95 per cent in three years. In 2005, the health authorities recorded 12,598 measles cases but in 2008 the figure fell to 278. From 2007 to 2008 the number of known cases of malaria also fell by 24%. The health ministry attributes this to recent campaigns of of insecticide spraying against mosquitoes, and improvements in malaria diagnosis and treatment. (Malaria of course often does vary greatly from one year to the next.) The figures were released by Health Minister Ivo Garrido during a meeting of his ministry's Coordinating Council. They are reported on allAfrica.com.

World Water Day

22nd March is World Water Day. The focus of the Day this year - "Transboundary Water" - is less directly of relevance to the health community than has been the case in previous years, when issues such as sanitation and poverty alleviation have been the focus. But the fact remains that many of the infectious diseases of poverty (for example, cholera) are water-borne and inadequate access to a safe water supply is a key factor in others (such as trachoma). A look at the World Water Day website is therefore recommended. Also worth reading is a Water Water Everywhere, But Not A Drop To Drink - an article by Shobha Shukla of the Citizen News Service.

Cholera - the need for education

There are still many parts of the world where the general population lacks an understanding of what causes infectious diseases, such as cholera. A report from Mozambique on allafrica.com demonstrates this. It is therefore good to hear that in the country which now faces the world's most severe cholera epidemic - Mozambique's neighbour, Zimbabwe - UNICEF is working in schools to educate children about what causes the disease, how it spreads and how it can be prevented.

Southern Africa's cholera

Most of the countries in southern Africa have been affected by the current cholera outbreak. While it is not the only afflicted nation, Zimbabwe, due to the total collapse of its economy and infrastructure, faces the most serious situation. According to all reports - for example, this in the Guardian (UK) - the epidemic continues to worsen. It is therefore good news to hear that case numbers in neighbouring Zambia appear to have dropped sharply - see this report from AfricaNews. Have you been affected in any way by southern Africa's cholera outbreak? Share your experiences with readers of TropIKA.net. What lessons do you think can be learned from the epidemic and the way it has been handled by health authorities in the countries concerned?

WHO and Zimbabwe's cholera epidemic

The World Health Organization is now issuing regular updates on the worsening cholera situation in Zimbabwe, where a total of 26 497 cases, including 1 518 deaths, have been reported by the Ministry of Health. Of great concern is the fact that case fatality rates (which are averaging over 5%) are much higher than the internationally accepted norm of 1%. WHO also has a photo gallery of its work against cholera in Zimbabwe.

Cholera and commitment

If ever there was an infection that could be described as an infectious disease of poverty then surely it is cholera. It is one of the most readily preventable of diseases, but individuals are severely limited in their ability to protect themselves from it if they have no access to safe water. It is a disease where, according to the World Health Organization, case fatality rates should be below 1%, but that requires effective basic health services. In the fight against disease the call is always for greater 'political commitment'. There are of course different degrees of commitment, but it is only when a country's government has no commitment whatsoever towards the health and welfare of its people that cholera can reach the current levels being seen in Zimbabwe. The number of cases in the Zimbabwean outbreak is not clear but UNICEF says the figure will soon reach 600,000. According to WHO, the overall case fatality rate is 4% but it is 20–30% in remote areas. Many hundreds have died. The situation is now an international emergency. Zimbabweans are fleeing poverty, repression and disease in growing numbers, taking cholera with them to Bostwana, Zambia and South Africa. All visitors to TropIKA.net are people with an interest in the infectious diseases of poverty but what are we to do about Zimbabwe? The TropIKA.net mission is to "to share essential information and to facilitate identification of priority needs and major research gaps". Yes, more research is needed on cholera - see information on the Initiative for Vaccine Research here. However, the need for political commitment to safe water and basic health services is greater than the need for research. What can the research community do in such circumstances? Let us know your views. [For a WHO fact sheet on cholera see here.]