Distribution and prevalence of malaria parasites among long-tailed macaques (Macaca fascicularis) in regional populations across Southeast Asia


Background: Plasmodium knowlesi and Plasmodium cynomolgi are two malaria parasites naturally transmissible between humans and wild macaque through mosquito vectors, while Plasmodium inui can be experimentally trans‐ mitted from macaques to humans. One of their major natural hosts, the long-tailed macaque (Macaca fascicularis), is host to two other species of Plasmodium (Plasmodium fieldi and Plasmodium coatneyi) and is widely distributed in Southeast Asia. This study aims to determine the distribution of wild macaques infected with malarial parasites by examining samples derived from seven populations in five countries across Southeast Asia. Methods: Plasmodium knowlesi, P. cynomolgi, P. coatneyi, P. inui and P. fieldi, were detected using nested PCR assays in DNA samples from 276 wild-caught long-tailed macaques. These samples had been derived from macaques captured at seven locations, two each in the Philippines (n = 68) and Indonesia (n = 70), and one each in Cambodia (n = 54), Singapore (n = 40) and Laos (n = 44). The results were compared with previous studies of malaria parasites in long- tailed macaques from other locations in Southeast Asia. Fisher exact test and Chi square test were used to examine the geographic bias of the distribution of Plasmodium species in the  macaque populations. Results: Out of 276 samples tested, 177 were Plasmodium-positive, with P. cynomolgi being the most common and widely distributed among all long-tailed macaque populations (53.3 %) and occurring in all populations examined, followed by P. coatneyi (20.4 %), P. inui (12.3 %), P. fieldi (3.4 %) and P. knowlesi (0.4 %). One P. knowlesi infection was detected in a macaque from Laos, representing the first documented case of P. knowlesi in wildlife in Laos. Chi square test showed three of the five parasites (P. knowlesi, P. coatneyi, P. cynomolgi) with significant bias in prevalence towards macaques from Malaysian Borneo, Cambodia, and Southern Sumatra, respectively. Conclusions: The prevalence of malaria parasites, including those that are transmissible to humans, varied among all sampled regional populations of long-tailed macaques in Southeast Asia. The new discovery of P. knowlesi infection in Laos, and the high prevalence of P. cynomolgi infections in wild macaques in general, indicate the strong need of public advocacy in related countries. Keywords: Plasmodium knowlesi, Plasmodium cynomolgi, Macaca fascicularis, Geographic distribution, Biased infection rate Read full article here: 2016_malaria-article

Authors “Xinjun Zhang1 , Khamisah Abdul Kadir2 , Leslie Fabiola Quintanilla‑Zariñan1 , Jason Villano3 , Paul Houghton4 , Hongli Du5 , Balbir Singh2* and David Glenn Smith1*”

Pine Cones: Natural, Destructible Enrichment Opportunities for NHPs

By Stefanie Nelsen

It is our responsibility and obligation to provide an environmental enhancement program that promotes for excellent animal welfare, specifically aimed at improving the psychological well-being of any nonhuman primate (NHP) in our care. We can accomplish this through appropriate behavioral observations, teaching our animals to be willing workers that cooperate with our human staff, and providing species specific and age appropriate enrichment opportunities that are biologically significant to the animals that we are enriching. This is done by focusing upon the 5 categories of enrichment: Social, Occupational, Structural, Sensory, and Nutritional.pinecone1 Pine cones fall under the occupational and sensory categories of enrichment. They are a natural item that the NHPs can touch, smell, look at, and even destroy. They encourage fine motor movements, such as foraging, which allows for the animal to exhibit species typical and appropriate behaviors.

pinecone2Pine cones can also be elevated in many ways, for example:
  •  Scent Enhanced (e.g. cinnamon, nutmeg, cilantro etc.)
  • Peanut Butter and More (e.g. add seeds, nuts, raisins etc.)
  • Color Enhanced (e.g. spray on color frosting)
  • Frozen (e.g. water and nuts or raisins, applesauce etc.)

For any questions on pine cones and/or suggestions on how to utilize a pine cone, please email

Hendry County Florida: An Ideal Environment for Nonhuman Primates

By: Thomas J. Rowell

Hendry County, located in Southwest Florida, has made news headlines in the last few weeks highlighting the construction of primate facilities in the county. Although Primate Products, Inc. (PPI) has been established in the area for over 15 years these new efforts have gained more than their share of attention from animal activists, both local and from outside the State of Florida (see links at end of article).  Much of the attention is directed to the number of primate facilities that have taken up residence in the county.  News stories have reported that “the county seat of LaBelle only has around 4,600 residents, meaning that the number of monkeys in the area could soon overtake the number of residents” and some local residents have expressed concern in the County’s methods of approving these new projects. hendry1PPI has operated Panther Tracks Learning Center, located approximately 22 miles southeast of Immokalee, FL and approximately 120 miles west-northwest of Miami, FL (at the northern edge of the Big Cypress Reserve) for over 15 years.  The reasons PPI, and we assume other enterprises involved in breeding and housing nonhuman primates in this area, selected Hendry County as the site for our facility is based on three critical criteria:
  • First and foremost, the weather.  The tropical savanna climate of Southwest Florida below the frost line is the only place in the continental US with the natural environment that is most similar to where our purpose bred monkeys originate.
  • Secondly, the agriculture mindset of the labor base.  No one has to explain to someone with a farm background that animals require care and support every day and are thus a 24/7/365 commitment.
  • Thirdly, the knowledge base of environmental and regulatory agencies in farm communities is second to none.  Their understanding of animal needs and farm construction requirements to meet the needs of animals and health issues for both humans and animals and thus their contribution to the location, design and construction of housing and support areas was vital and welcomed.
In early 2000 PPI was solicited and encouraged to open the operation in Hendry County by the Hendry County Economic Development Council.  During the review process, in front of the County Board of Supervisors, there were concerns expressed by some animal activist groups from outside of the county.  At open meetings many members of the Hendry County Cattleman’s Association and local farmers and business owners appeared in support the project.  Ultimately it was approved, and for the last 15 years we have worked closely with the county and the local community of which we have been welcomed into and have their full support.  We promote the interest of our county and local region through both our employment practices and by insuring we buy products and services from our local businesses whenever possible. Throughout the entire process the various public agencies (Agricultural Extension Office, Hendry County Planning and Zoning Agency, etc. along with State regulatory agencies including the South Florida Water Management District and Florida Fish and Wildlife Commission) contributed their knowledge to help us meet the rigid requirements required by the State of Florida. hendry2There is simply no better place to find the knowledge of support agencies, mindset of workers, and community understanding of farming and livestock production and maintenance than in Hendry County Florida. Hendry County and the community have been very supportive of PPI’s mission for over 15 years.  We draw our employment and bias our business to support the community, and we’ve always been very open with our practices and very appreciative of community support.

The Pole and Collar Handling System, Where It All Began…

The story of how the pole and collar handling system came to be, has two parts.  In the beginning ….the year was 1972, (for my generation, that was before masks, gloves and IACUCs), feral (wild caught) rhesus monkeys were still imported from India and cost about $60 each! At that time, Paul Houghton was working at the Stanford Research Institute (SRI) on a project with Jane Goodall to determine what behaviors in Chimpanzees were innate and which were learned. His group was training students from Stanford University (that were going to Gombe to do the behavioral shorthand that Dr. Goodall had developed), and helping with the design and building of a habitat for her chimps at the Stanford campus. As Paul tells it, “One day, they needed someone to catch and restrain some 10 kg rhesus macaques that were being dosed.  So they handed me the monkey gloves and said stick your hands in there and get their arms behind them and pull them out.”  For those of you who have done this you know what a rodeo this can be with an untrained large male macaque. Paul eventually went to Dr. Pinneo, the principal investigator of the project, and said “Doc, you don’t rope a milk cow every time you need milk – you train them.”  Dr. Pinneo’s response according to Paul was “Rhesus monkeys are not trainable.”  Paul’s response was “I can train them”, and two weeks later all of those animals were calmly presenting arms to be removed from their cages, and then handing their free arm back to me.  This was the beginning of the Willing Worker concept, which is simply stated as, training animals to willingly cooperate with the handling and procedures you need to accomplish.  By this effort animals become more of a participant in the procedure than a subject of the procedure.  A win-win situation! Over the next several years, word spread about their approach and they trained animals to cooperate in all kinds of protocols. They designed equipment to facilitate the work, and as a result, had more work than they could handle. In 1979 after Paul had left SRI, he received a call from John Anderson at the U.C. Davis Primate Center, asking what the best restraint device for monkeys was.  Paul told him that there just wasn’t one.  Monkeys perch, they don’t sit like apes, and that what was available was problematic because they pressed on various parts of their bodies and made them sit, which resulted in decubitus ulcers, even
Figure 1: Original Restraint Chair
Figure 1: Original Restraint Chair
from short sessions. The available devices just weren’t designed around either the natural behavior or the anthropometrics of the monkey.  With the support of Roy Hendrickson (and his friends in the Association of Primate Veterinarians) they proceeded to borrow 8 or 10 different restraint devices that were being used by various institutions at that time.  They then evaluated the positives and negatives of each, and developed a concept for the actual restrainer that Primate Products, Inc. still sells today.  They wanted an extremely humane device that actually did not come into contact with the animal except on its feet, when the animal was in its natural perching position. With a series of complex curves shaped into the various panels, they managed to prevent the monkey from “spinning”, and instead, orient in one direction, while remaining in its natural perching position. They developed the restrainer around the animal they desired to restrain, instead of putting the animal into something that wasn’t developed with that in mind. They wanted a device that was sturdy and would last.  To date many of the restrainers they produced as far back as 1983 are still in use today (see Figure 1).  And now, the rest of the story… Integral to the restrainer, they developed the pole and collar handling system (see Figure 2). This concept was developed from the work with dairy bulls where you use a stick with a hook in the ring in their nose to lead them around. If they start to push, you start to twist.
Figure 2: Original Pole and Collar
Figure 2: Original Pole and Collar
The concept was that if you don’t put your hands on the animal it can remain calm and not go into the flight panic response that results from their natural escape behavior.  They also wanted a solid member between the animal and the handler so anyone could use the system not just the special skilled (and brave) “catcher”.
Figure 3: Rhesus Macaque Training 1
Figure 3: Rhesus Macaque Training 1
They tried pistol handles, which according to Paul actually make it very difficult to manipulate in the catching process, and a variety of other embodiments.  The round handle with the simple pull slide matched with the correct hook style clearly became the favorite very quickly, and is what we use and sell today. The collar evolved much like the restrainer and the pole, from trying dozens of collars- flat and round leather dog collars to chains and rubber rings.  The current collar design was far superior because of how easily the animals adapted and accepted the collars in addition to the safety provided for the animal and the ease of use for the handler.  So the result was the pole and collar system that is generally still the preferred handling system used by the research community around the world today (see Figure 3).