From the Central African Medical Journal, 1963

An Epidemic of Laughing in the Bukoba District of Tanganyika

By A. M. RANKIN (Department of Medicine, Maskerere University College)
AND P.J. PHILIP(Medical Officer, Bukoba, Tanganyika)

An epidemic disease is defined as one that “is prevalent among a people or a community at a special time and produce by some special causes not generally present in the affected community” (MacNaulty, 1961). As the commoner epidemics are caused by the spread of viruses, bacteria, or parasites, there is a tendency to forget that abnormal emotional behaviour may spread from person to person and so take on an epidemic form. It is purpose of this communication to report and epidemic in the Bukoba district of north-west Tanganyika. The epidemic was characterized by episodes of laughing and crying. It is not only of interest from the sociological aspect but as it has disrupted the normal life of the community for six months, it is of considerable public health importance.

The disease commenced on 30th January, 1962 at a mission-run girls’ middle school at Kashasha village, 25 miles from Bukoba (see map). From that date until the 18th March, 1962, when the school was forced to close down, 95 of the 159 pupils had been affected. Fifty-seven pupils were involved from the 21st May, when the school was re-opened, until it was again shut at the end of June. The spread of the disease to other areas is described below.

Kashasha school is a barding school for girls between the ages of 12 and 18 years of age. The pupils sleep in dormitories where their ages are evenly distributed. The disease spread in a haphazard manner and did not involve the majority of the pupils in one dormitory at any one time. On the 30th January, three pupils commenced to act in an abnormal manner, and the disease rapidly spread through the school. None of the teaching staff which consists of two Europeans and three Africans was affected.

CLINICAL PICTURE
The clinical picture has varied slightly from place to place, but it is basically the same. Most of the victims have been adolescent school girls and school boys, though adult males and females have also been involved. No literate and relatively sophisticated members of society have been attacked.

The patient has had some very recent contact with someone suffering from the disease. The incubation period is from a few hours to a few days. The onset is sudden, with attacks of laughing and crying lasting for a few minutes to a few hours, followed by a respite and then a recurrence. The attack is accompanied by restlessness and on occasions violence when restraint is attempted. The patient may say that things are moving around in the head and that she fears that someone is running after her. The examination is notable for the absence of abnormal physical signs. No fever was detected, although some reported that they had had fever after a few days. The only abnormalities found were in the central nervous system. The pupils were frequently more dilated than controls, but always reacted to light. The tendon reflexes in the lower limbs were frequently exaggerated. There were no tremors or fits or losses of consciousness. The neck was not stiff.

COURSE OF THE DISEASE
No fatal cases have been reported. Symptoms have lasted from several hours in a few cases up to a maximum of 16 days. During this time the patient is unable to perform her normal duties and is difficult to control. The majority of those affected have had more than one attack separated by a period of normality. The maximum number of attacks was four. No serious sequelae have been reported. However school teachers state that for several weeks after the recovery the girls are unable to attend well to their lessons.

SUBSEQUENT SPREAD OF THE DISEASE
About 10 days after the Kashasha school was closed for the first time and pupils sent home, the disease broke out at Nshamba village complex, 55 miles west of Bukoba. Several of the sick girls from Kashasha came from this village. During April and May, 217 people out of a total 10,000 were attacked. The majority of these were young adults of both sexes and the remainder school children. All the patients recovered and the disease has apparently died out in this area.

Ramashenye girls’ middle school is situated on the outskirts of Bukoba. Between 10th and 18th June, when the school was forced to close, 48 girls were attacked out of a total of 154. Girls from Kashasha suffering from the disease had recently been sent to their homes in the vicinity of the Ramashenye school.

A further outbreak occurred in the village of Kanyangereka, 20 miles from Bukoba on the 18th June. A pupil from Ramashenye school had been sent home to this village on the 17th, as she was impossible to control at the school. The outbreak in her village occurred in her immediate family, with involvement of the sister (16), brother (9) and mother-in-law, (18). The sister-in-law of the father walked 10 miles to see how the sick school girl was and within a few hours was also laughing and violent.

Other people in the village soon became affected and the two boys’ schools 10 miles away were forced to close down. No case involving village headman, policemen, school teachers, or people of similar educational background was found.

At the time of writing this paper the disease is spreading to other villages, the education of the children is being seriously interfered with and there is considerable fear among the village communities.


INVESTIGATIONS
Investigations were carried out to determine if the disease had an infections, toxic, or psychological aetiology. Lumbar puncture was carried out in 17 cases and biochemical, bacteriological and microscopic examination showed no abnormality. Virus studies were done with the help of the Virus Research Institute at Entebbe. Blood taken from 15 active cases failed to grow and virus and no viral antibodies were found either in those who had recovered from the disease or in the people who had not been affected.

An attempt was made to find a common food factor that might contain a toxic substance capable of producing the clinical picture. The water supplies varied from rainwater collected in sealed tanks at the Kashasha school to local wells and streams at smaller villages. Kashasha school obtained their Matoke bananas, beans and meat from nearby villages, where no cases of the disease had been reported. Maize flour for Kashasha and Ramashenye schools is purchased in Bukoba but is manufactured in the area south of Lake Victoria. Bukoba hospital and several schools that have not been attacked by the disease are supplied with the same flour. This applies to ground nuts. Sample of maize flour and ground nuts were examined macroscopically for evidence of contamination with extraneous seeds but none could be detected.

Evidence was sought that this was a manifestation of hysteria in an epidemic form. There is no record of a similar epidemic occurring in the area before and thus there is no traditional name for it. The Bahaya, who form the bulk of the population, are calling it either “Enwara Yokusheka” (the illness of laughing) or “Akajanja” which means madness. No relevant information could be obtained from the pupils at Kashasha school who were originally affected, despite the fact that these investigations were done by a Muhaya education officer.

In Bukoba township, where the disease has aroused great interest, there is a belief that the atmosphere has been poisoned as a result of the atom bomb explo9sions. Others believe that someone has poisoned the maize flour. (Maize is not eater to any extent by the villages, who eat a basic diet of matoke. Most schools and hospitals, however, provide a basic diet of maize flour, as it is a much cheaper commodity.)

Many of the patients say that they are frightened of something, but do not give any further information. They appear to fear that someone is chasing them. There is a definite belief that this is a contagious condition of some kind. One villager described it as a spreading madness.

A milder outbreak with similar symptoms occurred near Mbarara, in Uganda, about 100 miles north of Bukoba. It started in February and involved about 60 pupils in a primary school. The disease has since ceased there.

DISCUSSION
The mode of spread of this disease would seem to be from person to person. In most instances it was possible to trace recent contact with someone exhibiting the same symptoms. This might suggest a virus disease spread by droplet infection. The results of the laboratory examination, the lack of abnormal signs on the physical examination and the fact that the majority of the patients had more than one attack of the disease are against an infectious aetiology.

Contamination of food by toxic substances is possible explanation. Seeds of Datura Stramonium contaminating wheat and maize flour have been responsible for epidemics of food poisoning in East Africa (Anderson et al, 1944; Raymond 1944). This disease begins soon after eating posho made from the flour contaminated with the seeds and bears a superficial resemblance to the present syndrome. However, the dry mouth, fixed and dilated pupils and the muscular inco-ordination found in datura poisoning were not seen in Bukoba. Also symptoms only last a few hours as opposed to the average of seven days with the illness under discussion. No food factor which was peculiar to the people attacked has been found. No foreign seeds were found in the maize samples taken. A toxic food factor could not explain the spread of the disease from one person to another.

The third possibility of mass hysteria seems the most likely explanation. We are at a loss to explain why the disease first started. Close questioning f the girls involved has failed to produce any reasons for the initial attack. Once started, this mass hysteria could spread without the original precipitating factors being present.

The middle ages in Europe produced several epidemics of mass hysteria, of which the dancing manias of Germany and Italy are the best known (Major, 1954.) These followed on the Black Death and are assumed to be a product of the dislocation of normal life caused by the plague.

Hecker (1844) describes the following example of how the tendency to sympathy and imitation increases under excitement: “In a Lancashire cotton shop in 1787 a woman worker put a mouse down the neck of a companion who had a dread of mice; the fit which she immediately threw continued with violent convulsions for 24 hours. On the next day three other women had fits and by the fourth no less than 24 people had been affected; among these was a male factory worker so exhausted by restraining the hysterical women that he had caught the illness himself. The disease spread to neighbouring factories because of the fear aroused by a theory that the illness was due to some sort of cotton poisoning.”

In Tanganyika, in the village of Kanyangereka, where most of one family were attacked, a man of 52 years of age living nearby saw these people during their attacks. He was very upset at the sight of their suffering, and soon after returning to his hut, where he lived along, he felt something telling him to laugh and cry and shout. This he continued to do for most of the night.

The type of mental disorder that affects a community is influenced by the culture of this particular community. Examples of this are Amok and Latah in Malaya, Koro in China and Arctic Hysteria in Siberia (Leighton and Hughes, 1961). These authors describe a religious revival in Kentucky, U.S.A. in 1800 where the population became so fearful of their future after death that many began to exhibit jerky movements and to fall down in an apparent state of unconsciousness. Others took to barking like dogs, and this spread from person to person.

This epidemic in Tanganyika of laughing and crying requires further study. In order to interpret this behavior as normal or pathological, a study of the culture context should be made. The Kentucky outbreak followed a pattern similar to the emotional release of the New England revival a few years before. We can find no written or verbal record of this present epidemic having occurred in the Bukoba district previously.

SUMMARY
An epidemic of laughing, crying and restlessness in the Bukoba district of Northern Tanganyika is described. The disease commenced in a girls’ school and has since spread to other schools and to villages in the area. No significant abnormal physical signs were found and all laboratory tests were normal. There have been no fatalities. No toxic factor in the food supply was found. It is suggested that this is mass hysteria in a susceptible population. This is probably a culturally determined disease.