In the arid landscapes of Somalia, a hidden disease threatens the backbone of pastoral life.
Imagine a nomadic pastoralist in Somalia's Lower Juba region, relying entirely on his camel herd for sustenance, transportation, and social status. He notices his animals becoming progressively weaker, developing fevers and swelling, their milk production dwindling. This is the reality of "Dhukaan"—the local name for camel trypanosomiasis, a devastating parasitic disease that threatens both animal welfare and human livelihoods across the region.
Camel trypanosomiasis, known globally as surra, is a potentially fatal disease caused by protozoan parasites of the Trypanosoma genus. In Somalia, the primary culprits are Trypanosoma evansi and, to a lesser extent, T. simiae 1 .
Somalia possesses one of the world's largest camel populations, estimated at nearly 8 million head 1 . These animals are far more than livestock—they represent a critical source of food, currency, transportation, and social status 1 . Their unique ability to survive extreme arid conditions makes them ideally suited to Somalia's climate and indispensable to the pastoral communities that depend on them.
Milk and meat for sustenance
Currency and trade commodity
Essential for nomadic lifestyle
The parasite is mechanically transmitted between camels through the bites of blood-sucking flies such as tabanids and Stomoxys species 6 . Unlike some other forms of trypanosomiasis, surra doesn't require the tsetse fly for transmission, enabling it to spread across Somalia's vast territories.
Once infected, camels may show varied clinical signs: fever, progressive emaciation, anemia, subcutaneous edema, loss of appetite, nervous signs, abortion, and eventually death 6 . The disease creates generalized immunosuppression, leaving camels vulnerable to secondary infections 6 .
Parasites circulate in the bloodstream
Ingest parasites during blood meal
Parasites transferred to healthy camel during subsequent bites
A recent cross-sectional survey conducted from November 2022 to July 2023 aimed to determine the prevalence and importance of camel trypanosomiasis in Somalia's Lower Juba Region 3 .
Researchers employed both microscopic examination and structured interviews with herders to gather comprehensive data 3 . The study collected 126 blood samples from seven herds across three sites in the Kismayo district, selected through convenient sampling of camels brought for watering or browsing.
Blood samples were obtained from each animal and placed in heparinized microhematocrit capillary tubes 6 .
Tubes were spun in a microhematocrit centrifuge at 12,000 rpm for 5 minutes to concentrate potential parasites 6 .
PCV was measured to determine anemia levels, with values below 24% considered anemic 6 .
Seven herders were interviewed about their awareness of the disease, its importance, and local names 3 .
The study revealed an overall prevalence of 10.3% at the individual level and 57.1% at the herd level 3 . This means that while not every camel was infected, the majority of herds contained at least one infected animal.
| Risk Factor | Category | Prevalence | P-value |
|---|---|---|---|
| Overall | - | 10.3% | - |
| Body Condition | Poor | Significantly Higher | 0.032 |
| Good | Lower | - | |
| Herd | Between Herds | Varied Significantly | 0.005 |
| Site | Between Sites | Varied Significantly | 0.005 |
| PCV Level | Low (<24%) | Strong Association | 0.001 |
| Mixed Infection | With other parasites | Significant Association | 0.019 |
The research found that infected camels had significantly lower PCV values (24.85±5.87%) compared to their non-infected counterparts (26.64±2.68%), indicating anemia as a key clinical sign 3 . Similarly, camels with poor body condition scores had significantly lower mean PCV values than those with good body condition 3 .
All interviewed herders were well aware of surra, known locally as Dhukana, and could accurately describe its clinical symptoms, seasonal patterns, transmission routes, and control methods 3 . The disease ranked as the third most important constraint to camel health and productivity in the region 3 .
The Lower Juba study relied on microscopic examination, which represents just one tool in the diagnostic arsenal. Research across different regions reveals striking differences in detection rates depending on the method used.
| Location | Study Period | Microscopic Exam | Serological Tests | Molecular PCR | Source |
|---|---|---|---|---|---|
| Lower Juba, Somalia | 2022-2023 | 10.3% | - | - | 3 |
| Banadir, Somalia | 2015-2016 | 0% | 68.7% (CATT) | 2.7% (ITS1-PCR) | 1 |
| Cholistan Desert, Pakistan | 2012-2013 | 0.7% (GST) | 47.7% (CATT) | 30.5% (RoTat1.2 PCR) | 2 |
| Egypt | 2020 | 17.3% (TBS) | 18.9% (CATT) | 22.7% (PCR) |
The stark contrast in Somalia between 0% detection by standard methods versus 68.7% by serological tests in the Banadir region highlights the critical limitation of microscopic examination alone 1 . This limitation stems from fluctuating parasitaemia levels in infected animals, where parasites may be absent from the bloodstream during examination despite active infection 5 .
| Method | Type | Function | Advantages | Limitations |
|---|---|---|---|---|
| Buffy Coat Technique | Parasitological | Concentrates & detects motile parasites in blood | Low cost, quick results | Low sensitivity, requires trained personnel |
| Giemsa-Stained Smear | Parasitological | Visualizes parasites in blood films | Simple, inexpensive | Low sensitivity (<10,000 tryp/ml) |
| CATT/T. evansi | Serological | Detects antibodies against T. evansi | Rapid, field-friendly, high sensitivity | Cannot distinguish current vs. past infections |
| ELISA | Serological | Detects antibodies with enzyme immunoassay | High throughput, sensitive | Requires equipment, cross-reactivity possible |
| ITS1-PCR | Molecular | Amplifies specific DNA sequences | High sensitivity & specificity, species identification | Requires specialized equipment & training |
| RoTat 1.2 PCR | Molecular | Targets specific VSG gene | Detects T. evansi type A | May miss non-RoTat 1.2 strains |
The high prevalence of trypanosomiasis in Somali camels, particularly in nomadic herds 1 , calls for urgent control measures. The disease significantly impacts camel health, productivity, and the pastoral economy.
Identifying and treating infected animals, particularly during high-risk seasons .
Reducing populations of biting flies that mechanically transmit the parasite.
Adjusting grazing patterns and animal movements to minimize exposure.
The battle against Dhukaan continues—a race between evolving diagnostic science and an ancient parasite threatening Somalia's desert giants.