Communicable Diseases in Iraq
By Stan Deresinski, MD, FACP
Source: Communicable Disease Profile: Iraq. WHO/CDS/2003.17. Updated 19 March 2003.
The World Health Organization (WHO) profile of communicable diseases in Iraq was recently updated. The stated purpose of this publication is "to provide public health professionals working in Iraq and neighboring countries with up-to-date information on the major communicable disease threats faced by the population." It is not comprehensive in its coverage. Given the recent events in Iraq, including our assumption of responsibility for the Iraqi population and the intrusion of large numbers of non-Iraqis into the country, a review is timely.
The population of Iraq in 2002 was approximately 27 million, with 3.6 million younger than 5 years and almost 700,000 children younger than 1 year. The mortality rate for those younger than 5 years is 133 per 1000 live births, and the infant mortality rate is 105 per 1000 live births, with a maternal mortality rate of 370 per 100,000 live births. The life expectancy at birth for men is 56.7 years and 62.9 years for women.
Acute Lower Respiratory Infections (ALRI)
ALRI and diarrheal illnesses together account for 70% of deaths in children younger than 5 years. WHO indicated that the number of cases of pneumonia increased from approximately 32,000 cases in 1990 (pre-Gulf War I) to 153,000 in 2000. The malnutrition reported to be widespread among children may have contributed to this apparent increase.
The last year for which human anthrax data from Iraq were available is 1980, when 269 cases were identified. Examination of data from 2 of Iraq’s neighboring countries, however, indicates that there were 220 cases in Iran in 1999 and 532 cases in Turkey in 2001. No cases were reported from Jordan, Kuwait, or Syria in 2001, and no data were available from Saudi Arabia. WHO states that outbreaks of animal anthrax, especially in ovine species, occur "almost yearly" in Turkey and Jordan.
There were 718 reports of cholera through the first 8 months of 2002, with most cases occurring in June, July, and August. Risk is present throughout the country but is greatest in rural areas. "While before 1991 the country had a well-developed water and sanitation system (90% of the urban and 70% of the rural population was estimated to have access to safe drinking water), in 2000 drinking water was accessible to only 50% of urban and 33% of rural populations in south/central Iraq."
Crimean-Congo Hemorrhagic Fever (CCHF)
Only 4 cases of CCHF were reported in 2001, for an incidence of 0.02 per 100,000 population. CCHF is likely present throughout the Middle East, and outbreaks occurred in Iran in 2000, 2001, and 2002, when 41 cases with 6 deaths were identified.
The incidence of diarrhea in children younger than 5 years was reported to have increased from a mean of 3.8 episodes per child per year in 1990 to nearly 15 episodes in 1996, with a 1.7% case fatality rate at mid-decade.
The Iraqi Ministry of Health reported that the number of cases of dysentery increased from approximately 20,000 in 1989 to 63,000 in 1993. In 1997, 12% of children aged 2 months to 5 years seen at health facilities had blood in their stools. A 1997 health survey found that 46% of children in this age range presenting with diarrhea were malnourished, 12% severely so, but the most important risk factor is lack of safe water and frequent poor sanitation.
The WHO document indicates that there were approximately 662,000 cases of amebic dysentery and 560,000 cases of giardiasis in 2001, for incidence rates per 100,000 population of approximately 2500 and 2100, respectively.
Thirty-two cases of diphtheria were reported in 2001. This represented an incidence of 0.12 per 100,000 population. In 2002, an estimated vaccine coverage (3 doses of dTP) rate of 67% was reported.
It was estimated that fewer than 1000 living individuals were HIV-infected at the end of 2001. Only 4 new cases were reported in 2001, and each was reported to be transfusion-related.
In 2001, 625 cases of cutaneous leishmaniasis were reported. The incidence rate for that year was 2.3 per 100,000 population. In Iraq, the agent of anthroponotic cutaneous leishmaniasis (ACL) is L tropica and that of the zoonotic disease (ZCL) is L major. The main animal reservoir of zoonotic cutaneous leishmaniasis is believed to be the gerbil.
While the historical focus of ACL, a predominantly suburban disease, was Baghdad ("Baghdad Boil"), its current main focus is in the poor suburbs of Mosul. ZCL, the more common form of cutaneous leishmaniasis in Iraq, is present in rural areas throughout the country but is most prevalent in the northern and western regions, possibly related to an explosion in the gerbil population.
WHO indicates that 2893 cases of visceral leishmaniasis (VL; kal-azar) were reported in Iraq in 2001 for an incidence that year of 10.9 cases per 100,000 population. The major areas of endemicity are in central Iraq and the greater Baghdad metropolitan area, but, over the last decade, VL has extended its reach into additional areas, including that around Basra. Transmission occurs between May and October, after hatching of sandfly eggs, while the peak of identification of new cases occurs between December and January.
The etiologic agent of VL is generally L donavoni. However, after Desert Storm in 1991, VL due to L tropica was detected (often with great difficulty) in US military personnel (N Engl J Med. 1993;328:1383-1387).
Major outbreaks of malaria occurred after the 1991 Gulf War, but reported cases have since decreased markedly. Nonetheless, 1120 cases of malaria were reported in Iraq in 2001, with 83% occurring in Dohouk, Erbil, and Suleimain, "governates" in the north bordering Turkey and Iran with a population of 3.7 million. Malaria is transmitted in additional scattered regions below 1500 meters, including the Basra region. Small, scattered, sporadic outbreaks are believed to occur in the southern and central areas of the country from the Tigris-Euphrates River basin to the border of Iran. There is no local malaria transmission in Baghdad. While risk exists in these areas from May to November, peaks occur in May/June and September/November.
Since only Plasmodium vivax is said to be present in Iraq, WHO recommends chloroquine prophylaxis for travelers to endemic areas.
Measles is the third most-frequent cause of death in Iraqi children younger than 5 years. In 2001, there were 4088 reported cases of measles; 51% of those had received no prior vaccine doses. The overall vaccine coverage in 2001 was estimated at 80% (Iraqi estimate) to 90% (WHO estimate). In south/central Iraq, more than two-thirds of cases are occurring in children aged 6-12 as a result of a vaccine shortage in the mid-1990s. WHO recommends as a priority to immunize children 6 months to 15 years, regardless of vaccination status or history of disease. All children 6 months to 5 years should also receive vitamin A supplementation.
Meningococcal infection was reported to have occurred in 501 individuals in 2001 (1.9 per 100,000 population).
An epidemic of pertussis involving at least 133 patients, only 40% of whom were younger than 5 years, occurred in 1996 in Basra. Coverage with at least 3 doses of dTP was estimated at approximately 67% in 2002. In 2001, a total of 2312 cases were reported, for an incidence for the year of 8.7 cases per 100,000 population.
The last known wild-virus polio case in Iraq occurred on January 26, 2000, and Iraq is currently considered polio-free. Vaccine coverage (2001) is estimated at approximately 80%.
Seven cases of rabies (0.03 per 100,000 population) were reported in 2001. Canine rabies is the most important source for human infection, although rabies is also present in wildlife, including bats. The estimated vaccine coverage in the country’s dog population in 1999 was only 1%.
No recent data are available, but the prevalence of S haematobium infection is reported to have decreased from about 60 per 100,000 in 1990 to about 20 per 100,000 population in 1994. The endemic areas include the Tigris and Euphrates river valleys. Of interest is that the intermediate snail host, Bulinus truncates, is not present in the rivers’ beds because of its intolerance to the high mineral salt content of the water. The snails are instead found in the vast marshlands surrounding these rivers in southern and central Iraq. Also of note is that the extent of urinary schistosomiasis in Mesopotamia has been influenced by the population movements related to pilgrimages to the 2 Iraqi holy cities of the Shia— Najaf and Karbala. Such pilgrimages had been in abeyance until the very recent Iraqi Shia pilgrimage to Karbala shortly after the end of hostilities. The opening of these sites to all Muslims is likely to lead to further extension of S haematobium in the area.
BCG coverage in 2001 was estimated at 85-93%. The estimated number of new cases of tuberculosis in Iraq was 30,211, of which 13,595 were smear-positive. The respective incidences were 132 and 42 cases per 100,000 population.
More than 21,000 cases of typhoid fever were reported in 201. Approximately 2% of the population is reported to be fecal carriers of Salmonella typhi. Patients with S haematobium infection have an increased risk of becoming urinary carriers of S typhi. Multidrug resistance, including to ciprofloxacin, is reported.
Dr. Derenski is Clinical Professor of Medicine, Stanford; Associate Chief of Infectious Diseases, Santa Clara Valley Medical Center