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Epidemiologic Notes and Reports Enterically Transmitted Non-A, Non-B Hepatitis -- East Africa

Outbreaks of enterically transmitted non-A, non-B hepatitis occurred in 1985 and 1986 at refugee camps for Ethiopians in Somalia and the Sudan.

Somalia. From January 1985 to September 1986, more than 2,000 cases and 87 deaths occurred at four refugee camps in Somalia; 40 (46%) of the persons who died were pregnant women. The first outbreak among refugees occurred in Bixin Dhule, a holding camp in northwestern Somalia. During the period January-March 1985, there were 699 cases of acute hepatitis and 13 deaths. Adults accounted for 81% of the cases and 92% of the deaths. From April-June 1985, Gannet refugee camp had more than 400 cases and 16 deaths, including nine (56%) among pregnant women.

After an outbreak was recognized at the Tug Wajale B refugee camp in northwestern Somalia, intensive epidemiologic investigation and serologic testing of cases were begun. In January 1986, there had been 2,500 refugees in this camp; an influx of new refugees had increased the population to approximately 32,000 by August 1986. Starting in April 1986, medical personnel at Tug Wajale B noticed a sharp increase in the number of hepatitis cases among adult Ethiopian refugees. In addition, a number of staff members had contracted hepatitis. Cases of hepatitis (diagnosed by the presence of scleral icterus) were identified by reviewing camp medical records. The peak number of cases occurred from mid-May to mid-June (Figure 1), about 6 to 7 weeks after the beginning of a rainy season. The majority (89%) of these persons with clinical cases were young adults; an equal number of males and females were affected. Symptoms associated with hepatitis were nausea, vomiting, dark urine, fever, abdominal pain, itching, fatigue, and headache.

During this period, there were 30 deaths due to hepatitis. Sixteen of those who died were pregnant women; four were non-pregnant women; nine were men; and one was a child. Only four maternal deaths from other causes were recorded in these months. The fatality rate for second- and third-trimester women with hepatitis was 17%.

A tent-to-tent survey involving 2,000 refugees revealed a 3% point prevalence of jaundice in adults and an overall attack rate (April to mid-June) of 8%. Among children 15 years of age, the point prevalence of jaundice was 0.2%, and the overall attack rate was 1.8%. Estimates indicated that over 2,000 cases of clinical hepatitis occurred during the study period. Among the Somali national staff the attack rate was 17%, whereas in expatriate medical personnel, the attack rate was 42%.

Serum samples were obtained from 84 patients and 50 age- and sex-matched controls, and stool specimens were obtained from 21 patients who had been jaundiced for less than or equal to 1 week. Nine patients (10%) and two controls (4%) were positive for hepatitis B surface antigen. Of these, only one patient was positive for IgM anti-core antibody, which is indicative of recent hepatitis B infection. None of the patients or controls were positive for IgM class antibody to hepatitis A virus. Stool specimens were examined by immune electron microscopy (IEM) using serum from a Pakistani patient with known enterically transmitted non-A, non-B hepatitis (1); 27-nm virus-like particles, similar to those seen by IEM in cases from Central Asia, Nepal, and Burma, were found in 13 of 21 samples. These particles cross reacted with sera from patients of enterically transmitted non-A, non-B hepatitis from Central Asia.

Sudan. In mid-1985, when outbreaks of hepatitis were occurring at the refugee camps in Somalia, there were reports of an increase in cases of acute jaundice in Eritrean and Tigrean refugees from Ethiopia residing in refugee camps in eastern Sudan. The investigation of this occurrence included intensified surveillance in four large reception centers (Wad Sherife, Shagarab East 1, Shagarab East 2, and Wad Kowli) and a case-control study in one camp (Wad Kowli).

Active case detection by expatriate health staffs, refugee health workers, and refugee organizations revealed an increase in cases of acute illness with scleral icterus among refugees from June-October (Figure 2), beginning approximately 6 weeks after the onset of heavy rains in eastern Sudan. The majority of patients were adults 15 years of age (66%); only 6.3% were children 5 years of age. There were almost twice as many cases reported among males as among females. Reported fatality rates ranged from 1.3%-4.7% and averaged 3.1% in the four camps. Eleven of the 63 persons who died were pregnant women.

Serum samples were obtained from 175 acutely jaundiced refugees. Seven patients (4%) were positive for hepatitis B surface antigen, and one of these was positive for IgM anti-core antibody. Three other patients (2%) had only IgM anti-core antibody, also indicative of recent hepatitis B infection. Eleven patients (6%) were positive for IgM-class antibody to hepatitis A virus and were considered to have acute cases of hepatitis A. The remaining 154 patients were considered to have non-A, non-B hepatitis. A pool of serum collected from non-A, non-B hepatitis patients cross reacted with stool samples from a Pakistani patient with known enterically transmitted non-A, non-B hepatitis (1).

A questionnaire regarding the onset of acute jaundice among expatriate staff while working in eastern Sudan refugee camps during 1985 has been distributed to 17 agencies involved. In addition, epidemiologic and clinical data are still being collected. Reported by: S Gove, MD, MPH, A Ali-Salad, MD, MA Farah, MD, D Delaney, MJ Roble, J Walter, Somalia Ministry of Health. N Aziz, MBBS, Sudan Commission on Refugees Health Unit. International Health Program Office; Hepatitis Br, Div of Viral Diseases, Center for Infectious Diseases, CDC.

Editorial Note

Editorial Note: Non-A, non-B hepatitis, which continues to be a diagnosis of exclusion, is considered to have two distinct forms, which are transmitted by different routes and presumably caused by different viruses. The first, initially recognized as post-transfusion non-A, non-B hepatitis, is seen commonly in North America and Europe, is epidemiologically similar to hepatitis B, and is recognized most commonly after blood transfusions and parenteral drug abuse. The second, enterically transmitted non-A, non-B hepatitis, is transmitted by the fecal-oral route. This disease is known to cause large outbreaks of viral hepatitis and has been reported in the Indian subcontinent (2-7), Burma (8), and Algeria (9). Frequently, large outbreaks have been linked to a fecally contaminated water source or have occurred after heavy rains in areas without systems for adequate sewage disposal. Person-to-person transmission can occur.

Enterically transmitted non-A, non-B hepatitis has several characteristic epidemiologic features. Its incubation period is approximately 40 days (as opposed to 30 days for hepatitis A and 60-180 days for hepatitis B). Clinical disease is common among adults, but infrequent among children. Pregnant women have a dramatically high mortality rate. Large outbreaks of acute viral hepatitis among adults in areas where the population is immune to hepatitis A should alert public health authorities to the presence of enterically transmitted non-A, non-B hepatitis.

Signs and symptoms of enterically transmitted non-A, non-B hepatitis are similar to those of other forms of viral hepatitis, although generalized pruritus may be more common. The majority of patients who are not pregnant recover completely, and there is no evidence of chronic liver disease as a long-term sequela. Outbreaks of disease may be identified by the suggestive epidemiologic pattern (especially the high mortality rate among pregnant women) and the exclusion, through serologic testing, of other forms of viral hepatitis. Post-transfusion non-A, non-B hepatitis has not been documented in communitywide outbreaks.

Currently, no serologic test is available for diagnosis; however, 27- to 30-nm virus-like particles have been found by IEM in stool samples of patients in the early acute phase of infection (1,7,10), and hepatitis can be induced in two different species of primates with this agent. Acute-phase antibody in sera may also be demonstrated by IEM.

In an outbreak situation, emphasis must be placed on preventing transmission. Water sources should be examined for fecal contamination. If the water supply is contaminated, all water should be boiled or chlorinated before consumption. Efforts to reduce person-to-person transmission by improving sanitation should be stressed. Immune globulin (IG) manufactured in the West does not appear to be effective in preventing disease. The efficacy of IG from endemic areas is unknown.

These reports mark the first time that this disease has been described as a problem in refugee camps and the first time that the characteristic virus-like particles have been identified in Africa. Refugee camps represent a fertile setting for the transmission of enterically transmitted non-A, non-B hepatitis. These camps usually have inadequate sanitation and are overcrowded. While contaminated drinking water was not a factor in this outbreak, this problem may exist in other refugee camps. Fecally contaminated, standing

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