Global Health Issue of Cholera in Somalia

Cholera in Somalia: Resources Determine Strategy

Cholera in Somalia

Cholera Background Information

Vibrio cholerae (cholera) is a Gram-negative bacterium that threatens human health when water and food supplies become contaminated (Weil, Ivers, and Harris, 2012). Its emergence occurs most often in crowded and unsanitary conditions and on average kills approximately 50% of those who develop symptoms and never receive treatment. Death occurs because a toxin secreted by the bacterium is endocytosed by epithelial cells in the small intestine, leading to unregulated cAMP production and chloride secretion into the lumen. The increasing chloride concentration in the lumen forces the body to secrete large amounts of water, potassium, sodium, and bicarbonate, leading to severe dehydration. The amount of fluid lost can reach 1 liter per hour in adults and if not compensated for, death follows in just hours.

The presumed ancestral home of cholera is the Ganges River Delta region, which is now Bangladesh (Mandal, Mandal, and Pal, 2011, 573-575). The first six of seven recognized cholera pandemics over the past two centuries are believed to have originated from this region. The seventh originated in the Celebes Islands of Indonesia in 1961 and from there spread around the world. The Classical 01 biotype is believed to have been the source of the first six pandemics, but may now be extinct, having been displaced by the more virulent 01 El Tor strain. First detected in 1905 in El Tor, Egypt, the 01 El Tor strain is believed to be the dominant biotype causing the current pandemic. A third strain, serogroup 0139, ravaged the Indian subcontinent in 1993 but never attained pandemic potential.

The estimated number of reported and unreported cases annually is believed to be 3 to 5 million, resulting in over 100,000 deaths (Weil, Ivers, and Harris, 2012, p. 2-5). The seventh cholera pandemic is therefore far from under control. More recently, a devastating earthquake in Haiti created a window through which cholera could enter a country with no history of cholera. With only 17% of Haiti's residents with access to adequate sanitation following the earthquake, 439,000 V. cholerae 01 El Tor cases led to 6,200 deaths in just 10 months. The source of this bacterium is believed to be a single asymptomatic United Nations aid worker from Nepal (Enserink, 2011). 75% of all infected individuals remain symptom free, but shed bacterium in their stools for up to two weeks (WHO and UNICEF, 2011).

Cholera Diagnosis

In resource-rich areas the Crystal VC® diagnostic test provides a rapid colorimetric indication of the presence of V. cholerae 01 El Tor and 0139 antigens in stool samples (Weil, Ivers, and Harris, 2012, p. 3). In resource-limited areas, stool samples can be cultured on taurocholatetellurite-gelatin or thiosulfate-citrate-bile salts-sugar agar. If culture media or equipment isn't available a dark-field microscopic examination of the stool for the characteristic motility provides a presumptive diagnosis.

Treatment Guidelines

By the time patients seek medical care they have typically lost 5% of their body weight. If rehydration treatment is started immediately fatalities can be reduced to below 1% (Mandal, Mandal, and Pal, 2011, p. 576). The main treatment is an oral rehydration salt (ORS) solution (WHO and UNICEF, 2006). In severe cases, intravenous fluids are combined with oral rehydration salts, and antibiotics may be used to reduce the duration of symptoms (Weil, Ivers, and Harris, 2012, p. 4). Zinc supplementation reduces stool volumes and diarrhea duration, and vitamin A is recommended for children between 6 mo. And 5 years. Solid food is also recommended and breastfeeding should continue.

Prevention

Water treatment, either chemically or by boiling, helps to reduce the prevalence of this water-borne disease in areas were potable water isn't available (Weil, Ivers, and Harris, 2012, p. 4-5). Hand washing is also effective, especially when preparing food. Two WHO-recommended vaccines have been shown to be 60% and 67% percent effective against 01 El Tor, or 01 El Tor and 0139 strains, respectively. Both could be used to produce a 'herd effect' if only a portion of the at-risk population is vaccinated, and the latter vaccine is cheap enough (U.S.$2 dollars) for use in developing countries.

WHO Cholera Case Study: Somalia

During the first 31 weeks of 2011 there were 4272 cases of acute watery diarrhea (AWD) at the Banadir Hospital in Mogadishu, Somalia, of which 75% were children under the age of 5 (WHO Somalia, 2011). This rate is a reflection of what is occurring throughout Somalia, because health care personnel are unable to keep up with the countless new villages that form randomly due to the ongoing conflict and drought conditions. Gaining access to conflict zones is generally impossible, so many internally displaced persons (IDPs) have no access to medical care, potable water, or hygiene products. The magnitude of the problem is revealed by the fact that another 74,400 persons were displaced from their homes between June and July last year.

The percentage of AWD cases resulting from V. cholerae is unknown, but sporadic testing indicated that 60% were due to cholera in the lower and middle Juba regions (WHO Somalia, 2011). In August, 2011 the WHO announced cholera incidence was increasing in Somalia and began to mount a rapid response in anticipation of the rainy season (WHO and UNICEF, 2011). Cholera was considered to be under control at the time, but the most recent cholera epidemic, which occurred in 2006, caused an estimated 67,000 cases. With this recent history in mind, plans were executed to prepare for treating 80,000 moderate and 20,000 severe cases of cholera by strategically positioning diarrheal disease kits in the most at-risk regions.

Essentially, everything that can be done is being done given the available resources. Trained community health personnel are going door to door and providing hygiene education. Water sources serving approximately 500,000 residents and IDPs in the Mogadishu area are being chlorinated and household hygiene kits are being distributed. The hygiene kits include chlorine tablets, soap, and buckets. Based on United Nations estimates, U.S.$80 million is needed for health centers and another U.S.$78 million for water sanitation and personal hygiene products, but less than 40% of the needed funds have been raised.

Summary

Efforts to forestall the next cholera epidemic in Somalia are limited to the most at risk areas in the country, which seems appropriate given that cholera was considered under control at the time and funding for a vaccination program was lacking. Pre-rainy season preparations were based on the scale of the most recent cholera epidemic and limited to AWD treatment, community education, and household hygiene supplies for a limited section of the country. The current status of cholera epidemic prevention and treatment in Somalia is therefore limited primarily to crisis management, rather than prevention, and therefore could not meet demand if another cholera epidemic exceeded predictions.