Category Archives: NTDs

World Tuberculosis Day: United We Can End TB and Tropical Diseases

The theme of World TB Day is to Unite to end TB: leave no one behind. The communities affected by TB are also ones where tropical diseases like onchocerciasis and malaria are endemic. A successful strategy to control one disease should ideally be “united” with all basic primary health care interventions, thereby truly leaving no one behind.

While the causative agents differ between TB and tropical diseases such as malaria, lymphatic filariasis and Dengue, control of these diseases shares a common goal – “an urgent need to develop new vaccines for HIV/AIDS, malaria, and tuberculosis, as well as for respiratory syncytial virus and those chronic and debilitating (mostly parasitic) infections known as neglected tropical diseases (NTDs).” In addition to prevention, there is also need for integrated “treatment pipelines directed at NTDs, Malaria, tuberculosis (TB), and human immunodeficiency virus (HIV)/AIDS,” according to Asada.

There is also a need for integrated primary health care (PHC) programming. In the Journal of Infectious Diseases. Simon reports on linkages showing that, “Recent research suggests that NTDs can affect HIV and AIDS, tuberculosis (TB), and malaria disease progression. A combination of immunological, epidemiological, and clinical factors can contribute to these interactions and add to a worsening prognosis for people affected by HIV/AIDS, TB, and malaria.”

The possibility of integrating directly observed treatment (DOT) for TB treatment into community health worker (CHW)/PHC programs that addressed malaria treatment and onchocerciasis control was tested by the Tropical Disease Research Program (TDR) some years ago. CHWs in a few of the study sites were able to successfully include DOT for TB in their community duties, but in other sites community and health worker fears about stigma inhibited action.

TB, malaria and NTDs are among the conditions referred to as the infectious diseases of poverty. We will not eliminate poverty by tackling these diseases one-by-one. A “United” and integrated approach from national to community level is needed.

World Water Day: Water and Neglected Tropical Diseases

The United Nations introduces us to the challenges of water. “Water is the essential  building block of life. But it is more than just essential to quench thirst or protect health; water is vital for creating jobs and supporting economic, social, and human development.” Unfortunately, “Today, there are over 663 million people living without a safe water supply close to home, spending countless hours queuing or trekking to distant sources, and coping with the health impacts of using contaminated water.”

Haiti: Importance of Water to prevent STH

Many of the infectious health challenges known as Neglected Tropical Diseases (NTDs) have issues of water associated with their transmission. This may relate to scarcity of water and subsequent hygiene problems. It may relate to water quality and contamination. It may also relate to water in the lifecycle of vectors that carry some of the diseases.

Even though water is crucial to the control of many NTDs, it is not often the feature of large scale interventions. The largest current activity against five NTDs is mass drug administration (MDA) on an annual or more frequent basis to break the transmission cycle.  Known as diseases that respond to preventive chemotherapy (PCT) through MDA, these include lymphatic filariasis (LF), trachoma, onchocerciasis, schistosomiasis and soil transmitted helminths (STH) has been undertaken for over 10 years.

We have recently passed the Fifth Anniversary of the London Declaration on NTDs, which calls for the control of ten of the many these scourges The Declaration calls for “the elimination “by 2020 lymphatic filariasis, leprosy, sleeping sickness (human African trypanosomiasis) and blinding trachoma.” Another water-borne NTD, guinea worm, should be eradicated soon. Two of the elimination targets are part of MDA efforts, LF and trachoma.

Cameroon: mapping the community to detect NTD transmission sites

Ministries of Health and their donor and NGO partners who deliver MDA against the 5 diseases in endemic countries express interest in coordinating with water and sanitation for health (WASH) programs. People do recognize the value of collaboration between NTD MDA efforts and WASH projects, but these may be located in other ministries and organizations.

The long term implementation of WASH efforts is seen as a way to prevent resurgence of trachoma, for example, and  strongly compliment efforts to control STH and schistosomiasis. Hopefully before the 10th Anniversary of the London Declaration the vision of “ensuring access to clean water and basic sanitation,” can also be achieved.

Finally as a reminder our present tools for the control of Zika and Dengue fevers relies almost entirely on safe and protected household and community sources of water to prevent breeding of disease carrying Aedes aegypti mosquitoes. If we neglect water, we will continue to experience neglected tropical diseases. Hopefully the topic of water and NTDs will feature prominently at next months global partners meeting hosted by the World Health Organization.


Identifying a More Accurate Test for Schistosomiasis in The Gambia

During the recently concluded 65th Annual Meeting of the American Society of Tropical Meicine and Hygiene colleagues from The Gambian Ministry of Health and Social Welfare, the World Health Organization and the NTD Support Center presented a poster entitled, “Field Performance of a Circulating Cathodic Antigen Rapid Test at Point-Of-Care for Mapping Schistosomiasis-Endemic Districts in Gambia.” The authors included Bakary Sanneh, Kristen Renneker, Joof  Ebrima, Sanyang M. Abdoulie, Camara Yaya, Sambou M. Sana, Sey Alhagie Papa, Jagne Sherifo, Baldeh Ignacious, Louis-Albert Tchuem Tchuente, Patrick J Lammie, and Kisito Ogoussan. Their abstract appears below.

figureBackground: The traditional parasitological Kato Katz smears and urine filtration methods recommended by the World Health Organization (WHO) to implement mapping of schistosomiasis have been found to be less sensitive in the detection of light-intensity schistosomiasis infections. Field surveys in Sub-Sahara Africa have shown that the Circulating Cathodic Antigen (CCA) point-of-care (POC) test is more accurate for detecting Schistosoma mansonia than the microscopic Kato Katz technique.

Aim: To establish the field sensitivity and specificity of POC CCA as mapping tool to provide the endemicity of schistosomiasis in The Gambia.

Methods: A cross-section study …

  • Ten school per region in 4 regions with historical known risk
  • Fifty children aged 7 to 14 years: 25 boys and 25 girls (WHO Mapping sampling guide)
  • Stool, urine and finger pricks samples were examined for Schistosomiasis
  • Parasitological tests: 2 Kato-katz slides to read from each stool sample, and urine filtration technique, urine dip-stick and Circulating Cathodic Antigen (CCA) techniques,

table-1Discussion: The CCA prevalence in this study was 23.34% (95% CI, 21.51-25.26%) two times higher than the prevalence based on  egg-detection for S. haematobium and S.mansoni (10.13,95% CI 8.87-11.55; and 0.26%, (95% CI, 0.09-0.62, respectively).  Although The Gambia is thought to be endemic for only S. haematobium, yet 5 subjects were found to harbor S. mansoni. Three of the 5 individuals from the high endemic schistosomiasis regions were co-infected with S. haematobium and S. mansoni.

table-2The sensitivity of the POC-CCA proved to be relatively high (60.0%), using double Kato-Katz as a reference for S. mansoni detection, although few infections were found, 5 out 1954  tested. The specificity of the POC CCA was 76.8%, respectively.  Using urine filtration as reference standard for the detection of S. haematobium, the sensitivity of POC-CCA was 47.9% and the specificity was 79.4%.

Conclusion: The Gambia is endemic for both urinary and intestinal schistosomiasis although most of the infections are due to S. haematobium in the 4 regions investigated. The results of the study showed a low sensitivity of the POC-CCA test in detecting S. haematobium and therefore we conclude further research is needed  to develop an ideal rapid diagnosis tool for urinary schistosomiasis.

schisto-acknowledgementAcknowledgement: Thanks to the Mapping Team,  Consultants, MoHSW, WHO,  Task Force for Global Health (TFGH) for all their support. For questions please contact: Dr. Kisito Ogoussan,; or Mr. Bakary Sanneh,

Malaria, Lymphatic Filariasis and Insecticide-treated Nets



Throughout Africa one of the main vectors that carry Lymphatic Filariasis (LF) is the Anopheles mosquito, which also carries the malaria parasite. The Carter Center has been promoting use of insecticide treated nets (ITNs) for many years as part of its LF control efforts, but others may not have gotten the message.

The global community is targeting LF for elimination in 2020. The primary strategy is mass drug administration annually with ivermectin and albendazole. The plan is that up to seven annual rounds of drug distribution in endemic communities where 90% of population coverage is achieved is necessary to stop LF transmission. The Carter Center explains that distribution of long-lasting insecticidal bed nets (LLINs) protects pregnant women and children who cannot take drug treatment.

The LF strategy often builds on and integrates with onchocerciasis control efforts where these diseases overlap. The community directed treatment with ivermectin (CDTI) model pioneered by the African Program for Onchocerciasis Control  (APOC), wherein communities or villages plan together the distribution process including selecting their own community directed distributors (CDDs). This model has also been used to distribute ITNs.

20160818_100110-1A second component of the LF strategy is morbidity management which focuses on enhanced personal hygiene or cleaning of the parts of the body that experience lymphedema. Another aspect uses surgery to address some of the worst effects, hydrocele.  While this component does not ‘control’ LF, it is a necessary effort to reduce suffering and the negative stigma from the disease.

To judge whether transmission has stopped and elimination has been achieved Transmission Assessment Surveys (TAS) are conducted with rapid diagnostic tests on young children after at least 5 years of MDA in a community.  Specifically WHO recommends an implementation unit must have completed five effective rounds of annual MDA defined as achieving rates of drug coverage exceeding 65% in the total population.

For example the Carter Center in Support of the Nigerian Federal Ministry of Health worked in Plateau and Nasarawa States through community health education, delivery of long lasting insecticide-treated nets (LLINs) and 33 million drug treatments for lymphatic filariasis and river blindness between 2000 and 2011. “In 2012, it was confirmed (through TAS) that lymphatic filariasis transmission had stopped. Post-treatment surveillance is currently underway to assure that the parasite is not reintroduced into the area.”

Another component of the assessment process is yet to be fully realized. That is the testing of mosquitoes for the presence of microfilariae. This indirectly implies an important role in preventing human-vector contact as would be achieved through the use of ITNs as well as indoor residual spray (IRS).

Vector control can benefit more than one disease. Integrated vector management is seen as a key tool to prevent reintroduction of LF in areas where anopheles mosquitoes carry the disease and where ITN campaigns are successful.

Ultimately the key to benefiting from the disease control synergies provided by insecticide-treated nets is an understanding what if any effect nets have on transmission. This poses a challenge in terms of separating it from the effect of MDAs as well as the fact that MDAs are time-limited. As MDAs are still underway in many places it is incumbent on program managers to monitor and evaluate the impact of all activities, treatment and vector control, over the next decade to determine the success of eliminating LF and hopefully malaria, too.

Malaria, Onchocerciasis and Ivermectin – Possibility of Eliminating Two Diseases

Many tropical diseases are co-endemic in a given country and environment. Therefore, it only makes sense to learn whether there can be common strategies and synergies in disease control and elimination efforts. Onchocerciasis or River Blindness is carried by the black fly (simulium damnosum) that breeds along the banks of fast flowing rivers and malaria are examples.

Onchocerciasis was eliminated in many settings in the Sahel through the process or aerial spraying of these riverbanks to kill the black fly larvae. Though the insecticide used was often the same as used for malaria larviciding, the habitats differed and no synergies were achieved then.


Merck donates ivermectin to achieve control and elimination of onchocerciasis

Through subsequent programs using community directed treatment with ivermectin (Mectizan ®) interventions sponsored by the African Program for Onchocerciasis Control (APOC) it was learned that ivermectin also had beneficial effects on malaria transmission.

Ivermectin had been used in agriculture not only for internal parasites of animals. The agricultural community has long known that ivermectin kills both internal parasites (worms) but is also effective against some external parasites (lice and ticks).

Around 2010 scientists began to consider the anti-mosquito effects ivermectin might have when humans consumed it. It turns out that after a mass distribution in a community of ivermectin for onchocerciasis that mosquitoes feeding on people who had recently swallowed ivermectin would die. This was demonstrated when mosquitoes bit volunteers who took ivermectin of the first few days after consumption died there was no effect in the group not taking the drug.


Ivermectin distribution sessions in a Cameroonian village

Of particular interest was the fact that people who had consumed ivermectin would contribute to mosquito mortality even when they were outdoors. While the effect was not long lasting, the onchocerciasis control programs in the Americas have shown that it is safe to administer the drug two or four times a year.

Research that looks at the malaria parasite concluded that, “it is likely that ivermectin treatment is arresting parasite growth.” The researchers note that, “given the prior use of ivermectin and its safety record in humans and animals, it can be considered in combination therapy with other antimalarials.” The issue of dosage would need to be tested further.  Ivermectin at sub-lethal concentrations even inhibits the sporogony of P. falciparum in An. Gambiae.

Because of the need to find new and complementary tools to eliminate malaria the Malaria Policy Advisory Committee (MPAC) of the World Health Organization’s Global Malaria Program considered at its recent meeting the role of endectocides including ivermectin in the future of malaria control and elimination and the importance of further research.

The future of malaria elimination requires finding new tools to integrate with and the strengthening of existing tools. If these efforts also benefit the control and elimination of other diseases, the public’s health will benefit.

Mosquito-Borne and Tick-Borne Illness in Florida: Importance of Surveillance

Class members from the course “Social and Behavioral Foundations of Primary Health Care” at the Johns Hopkins Bloomberg School of Public Health write a policy advocacy blog as part of their assignments. Here we are sharing the blog posted by “jleblan5jhmiedu“. read more on this and other SBFPHC blog posts by clicking here. This posting is particularly relevant today on World Mosquito Day.

Vector-borne diseases make up some of the more common infections throughout the globe. The Centers for Disease Control and Prevention acknowledges mosquito-borne denque mosqdiseases, such as West Nile Virus, and tick-borne infections, such as Lyme disease, have a great impact on the United States. These vectors have found favor in climate change as they continuing to breed and pose a public health risk; carrying infectious agents that may be transmitted to humans through a bloodmeal.

In 2014, the State of Florida Department of Health published their mosquito borne diseases surveillance guidebook. Within these guidelines, specific mosquito-borne infections were addressed in regards to both detecting and preventing such diseases. Unfortunately, since this publication, the Zika virus outbreak developed and was found to have recently reached Miami-Dade county in Florida, where locally transmitted cases were confirmed. Given these locally acquired infections in Florida, the surveillance guidelines should be updated accordingly.

FL Zika

Number of Florida Acquired Zika Virus (gray line: per million)

While the Northeastern regions of the US are known to have their “tick season” in the Spring and Summer, Florida’s climate allows for a year-long risk of contracting a tick-borne diease. The standard lab diauos in newsgnostic criteria for Lyme disease, the ELISA, detects antibodies against the bacterium, Borelia burgdorferi sensu stricto. However, it has continued to demonstrate poor sensitivity and overall reliability. Research from the University of North Florida has identified different strains of Borrelia that cause disease in humans. Thus, should one be infected with one of the different strains of Borrelia, one’s test is likely to be negative despite having actual disease. In recent years, Florida was found to have a 140% increase in Lyme disease cases since 1993 while reports of other tick-borne diseases have also increased. Hence, Florida researchers and public health professionals must partner together to revise and implement more up-to-date/accurate screening and awareness for vector-borne diseases.

Emergency Funding for Zika Virus Response

Class members from the course “Social and Behavioral Foundations of Primary Health Care” at the Johns Hopkins Bloomberg School of Public Health write a policy advocacy blog as part of their assignments. Here we are sharing the blog posted by Hanna B. More of the SBFPHC postings can be read at this link.


On February 22nd, the Presidential office requested $1.9billion in emergency funding to support activities related to Zika virus, but these efforts have dangerously stalled in Congress. To date, nearly $600 million has been redirected by the Obama administration to fund Zika related research, front line response efforts, and vaccine development. More than half of this money was redirected from within the U.S. Department of Health and Human Services (DHHS).


Source: Healthcareit

On August 3rd, Sylvia Burwell, DHHS Secretary, informed Congress that due to the delay in approving the emergency funding, the DHHS had been forced to further reallocate up to $81 million from other programs, including the National Institutes of Health. This was extremely important because it could impact the progression of the vaccine studies currently underway, as Secretary Burwell suggested in her letter to Congress. Her letter also outlined the response by the CDC and predicted that they too would be out of Zika funding by the end of the fiscal year (Sept 2016).

Funding approval for Zika virus related activities from the U.S. is more urgent than ever. As of August 17th, the U.S. has confirmed 14 cases of locally acquired Zika virus disease – all from Florida. This was after the U.S. Centers for Disease Control (CDC) announced on August 2nd that an additional $16 million was awarded to 40 states and territories to support Zika related public health activities.

So what can you do? It is time we let our political leaders know that their constituency will not wait any longer. Follow Secretary Burwell’s lead – petition your local congressional representatives (House, Senate) and let them know this is an issue you care about. Or submit pre-formatted online petitions at Project Hope and AmeriCares. And spread the word and call to action amongst your peers.


Source: Project Hope