Samuel T Darling – Pioneer and Malariologist

Samuel T Darling – Pioneer and Malariologist

Sam Darling, founder of NO MO Foundation and inventor of NO MO repellent is the grandson of Dr. Samuel Taylor Darling (1872 -1925). Sam grew up with a deep awareness of his grandfather’s legacy. During the early twentieth century, Dr. Darling was one of the world’s leading experts in tropical diseases.

He investigated malaria and other mosquito-borne diseases in Panama, the Far East, South Africa, Brazil and the southern United States. As a pathologist, he performed more than 4,000 autopsies on employees of the Panama Canal company who died between 1905 and 1914. This experience gave him a singular perspective on the anatomical pathology of tropical diseases. The results of his innovative work helped him to develop new concepts about diagnosis and treatment of malaria. In memory of his contribution to an understanding of malaria, the mosquito responsible for most malaria in Latin America (Anopheles darlingi) was named for him. Indeed, the efforts of the NO MO Foundation to reduce mosquito-borne disease in Africa are inspired by Dr. Darling’s own work on behalf of those who suffer most from mosquito borne disease: the poor.

Enrique Chaves-Carballo found Dr. Darling’s life so interesting, he wrote a book called The Tropical World of Samuel Taylor Darling ~ Parasites, Pathology and Philanthropy. Dr. Chaves-Caballo’s primary research was conducted at the Rockefeller Archives, National Archives, the US Library of Congress, and libraries in the former Canal Zone of Panama. His book is essential reading for medical historians and those interested in the history of sanitation, public health, malaria, and yellow fever. It provides a good understanding of the early twentieth century Panama Canal experience, and the Rockefeller philanthropy in tropical medicine and hygiene.

In response to Chaves-Carballo’s book, Dr. Gerald L. Baum, M.D. Professor of Medicine at Sackler School of Medicine, Tel Aviv University, states “This biography emphasizes not only the remarkable person that was Samuel Taylor Darling, but also redirects our attention to the terrible world of parasite infestation of humans. The shock comes from realizing that what Dr. Darling had to deal with almost one hundred years ago is still a major problem in a great part of the world today.”

In reflecting upon vector borne diseases, Dr. Baum makes an important link to poverty “The failure to achieve better control of these problems is closely related not only to personal poverty, but poverty of governments that cannot afford to establish effective public health systems. In addition the lack of means in a large part of the world results in the crowding and poor hygiene that fosters the spread of these diseases.” 

In his most recent endorsement of the NO MO Foundation Dr. Chaves-Carbello states that “many approaches have been directed to reduce the number of cases and deaths from malaria. Each of these has advantages and disadvantages. For example, insecticide-treated bed nets are often provided free, but many recipients do not use them, or they use them inappropriately. Additionally, a malaria vaccine initiative has not produced good results, as protection has been insufficient. Finally, insect repellents containing DEET have shown limited efficacy against important disease vectors and they’re too costly for poor populations. However, the product developed by Samuel Darling and the NO MO initiative has provided 100% protection for 10 hours in EPA-required field trials. In addition, the product is distributed below cost, thanks to contributions from concerned individuals. I urge everyone to contribute to this lofty endeavour by the NO MO Foundation to protect the lives of African children.”

Former Inverness resident raises funds for mosquito repellent efforts in Africa

Former Inverness resident raises funds for mosquito repellent efforts in Africa

The Point Reyes Light newspaper wrote an article about the NO MO Foundation’s work and Sam Darling, our founder, prior to our GO NO MO crowd funding launch. We have copied it here. The launch party kicked of our fundraiser which is still running strong! If you have not checked it out yet, make sure you do!

Former Inverness resident raises funds for mosquito repellent efforts in Africa


Of the estimated 429,000 deaths from malaria in 2015, nearly all occurred in Africa, and a startling majority were of children under the age of 5, according to the World Health Organization. “It has become an epidemic because people have no defense against it,” said Sam Darling, an organic grower whose company produces lemongrass for tea. Over a decade ago, Mr. Darling, who has lived in Inverness in the past, invented a low-cost mosquito repellent lotion whose active ingredient is lemongrass. Through a foundation called No Mo, he’s has been producing and distributing it to underdeveloped communities in Peru and Ghana. He is now ready to step it up. The foundation hopes to raise $60,000 in 30 days to train social marketers and expand into Tanzania and Uganda. A launch party will be held in Inverness Park next week. Working to contain the ravages of malaria is in Mr. Darling’s blood. His grandfather, Samuel Taylor Darling, was a renowned malariologist credited with controlling and preventing malaria during the construction of the Panama Canal. “It’s an ironic fact that the mosquito that causes 85 percent of malaria in the Americas, Anopheles darlingi, is named after my grandfather,” Mr. Darling said. The No Mo repellent uses a pair of crucial ingredients to deflect diseased vectors: p-Menthane-3,8-diol, a plant-derived molecule that produces a cooling sensation on the skin, and lemongrass oil. Mr. Darling produces lemongrass in Guatemala for use in herbal tea through his company Del Cielo; after decades of working with the tropical grass, he “stumbled” onto its amazing power to repel insects. The molecule extends the life of the oil—which alone can repel insects for less than an hour—to 10 hours. The repellent is also inexpensive to produce, and is sold at a low cost. (It costs $6.50 for a family of four in Ghana to use it daily for a month.) “I developed this for poor communities,” said Mr. Darling, who now resides on Salt Spring Island off the coast of British Columbia. “It wasn’t developed for wealthy gringos living in Ross who are afraid of Zika out on a barbeque—these are not the people who are threatened. This is for people living in huts in dirt floors who don’t have doors and screens.” Carlos Porrata, an Inverness resident who sits on No Mo’s board of directors, has known Mr. Darling for years and said it was a “no brainer” to join the nonprofit. “He’s starting to produce it big time, spreading it throughout Africa and nations that can’t afford insect repellent,” he said.


Healthkeepers Ghana

Healthkeepers Ghana

Supporting Women Distributors of NO MO Repellent

Our intention is to involve women as Independent Social Marketers of NO MO repellent in order to provide them with the opportunity to generate income and gain entrepreneurial skills. Why? Because if you provide a woman with information, training and a microloan she can lift up her entire family and contribute to the success of her whole community. The ripple effect is tremendous.

We are currently partnering with HealthKeepers Network (HKN) in Ghana.  HKN is a social microfranchise program which is modeled after the door-to-door sales approach similar to that of Avon.

Rural women are trained to provide basic health education of a variety of topics to their communities and make a modest income by selling health products that address common but deadly health problems. Going door-to-door carrying a basket on their heads the Health Keepers reach underserved and rural communities across Ghana. The products sold are a mix of high impact, reasonably priced health products, such as water purification tablets, condoms, oral rehydration salts, vitamin A, mosquito nets, antimalarial drugs, as well as personal care products. We are happy to report that NO MO repellent is now considered a popular item in their basket of health essentials.

Once we expand our reach to other countries, we hope to collaborate with organizations like Living Goods who operate social franchising models in Uganda and Kenya. In those countries where that model is not established yet, we will create our own network of trained social marketers.

EPA-Required Field Efficacy Test in Two Environments

EPA-Required Field Efficacy Test in Two Environments

The objective of the test was to determine the Complete Protection Time of NO MAS repellent (NO MO), when applied at a typical consumer dose, again wild populations of mosquitos including but not limited to species of the genera Culex, Anopheles, and Aedes, to provide data under the Data-Call-In requirements (EPA Reg. No. 3126-LRN0) of United States Environmental Protection Agency Guideline OPPTS 810.3700.

This mosquito repellent study was sponsored by Mr. Sam Darling of the Del Cielo foundation (Salt Spring Island, British Columbia, Canada), to provide efficacy data in support of a pesticide registration application to the United States Environmental Protection Agency. The test material, based on the active ingredients p-menthane-3,8-diol (PMD) and lemongrass oil (citral), is No Mas, a topical lotion repellent.

The study Protocol was reviewed and approved by Independent Investigational Review Board, Inc., and reviewed favorably by the US Environmental Protection Agency and its Human Studies Review Board, and by the California Environmental Protection Agency.

We conducted a dosimetry study in advance of efficacy testing in order to estimate typical consumer dosing behavior. The resulting average dosing rates, of 1.20 μl/cm2 on arms and 1.04 μl/cm2 on legs, were then employed as the rates for the subjects in the field efficacy study. These results were also used to estimate the Margin of Exposure (MOE) relative to acute dermal toxicity limit dose in No Mas (>5000 mg/kg, see toxicity test reports), resulting in Margin of Exposure (MOE) values of >583 (arms) and >287 (legs) for the repellent. We judged these margins to be sufficiently great to justify dermal exposure of the subjects to the test materials during efficacy testing.

Efficacy was tested in two different habitats under expected environmental conditions for consumers using the product. In each habitat, ten human subjects (five female, five male) each exposed a No Mas repellent-treated limb to mosquitoes for one minute every 15 minutes, until product failure or cessation of the test. Simultaneously, one male and one female untreated control subject exposed arms or legs in the same manner, in order to assess mosquito biting pressure. Both controls experienced landings within one minute of exposure throughout each test day, indicating that mosquitoes were suitably active for the efficacy study.

Under field conditions, the repellent provided substantial and prolonged protection against the mosquito species (Aedes melanimon, Ae. vexans, Ae.nigromaculis, Culex tarsalis, and Anopheles freeborni). Mean Complete Protection Time (CPT) for No Mas was 9.8 hours at Site 1 and 10.1 hours at Site 2.

In summary, No Mas repellent at 16% PMD and 2% lemongrass oil concentrations provided prolonged periods of Complete Protection against several species of mosquitoes, including species significant to public health.

Download Research Article: