Helminthiasis in Lagos, Nigeria

645 ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE. Vol. X X X I I . No. 5. February, 1939.

TRANSACTIONS OF THE

HELMINTHIASIS

IN LAGOS, NIGERIA.

BY G U Y H. F I S K , M.D., C.M., D.T.M. & H.*

Colonial Medical Service, Nigeria.

Varying opinions have been held concerning the incidence of helminthic infestation amongst the Africans of Nigeria. Some have said that the infestation is very light and of no importance while others maintain that helminthiasis is a very important cause of ill-health in the Nigerian native. I have attempted to determine the number and variety of worms carried by the average Lagosian. In order to avoid the disadvantages of estimating the number of worms present from the quantity of eggs passed in the faeces I decided to count only the worms present in the dead body. One hundred and twenty bodies were examined for intestinal helminths in the Laboratory of the African Hospital, Lagos, from December, 1937, to April, 1938. The cases were unselected and consisted of consecutive routine autopsies comprising hospital deaths, Coroner's cases, and " Health " cases. These last are people who die in the district of Lagos without a medical certificate. The series therefore includes both the educated African who attends for hospital treatment and his less civilized brother who as yet does not appreciate the value of proper medical attention. It also includes those suffering from disease and those accidentally killed at a time when they were presumably in good health. The following technique was used in collecting the worms: the gastrointestinal tract was removed in its entirety from the body and opened in a large white enamel tray. The contents of the intestine were then emptied into this tray and the entire wall of the intestine was thoroughly scraped. When all visible worms had been picked out, the faecal material was broken up with water and allowed to settle. After settling, the supernatant fluid was poured off and any visible worms removed. This process was repeated until no more worms could be f o u n d f u s u a l l y about twelve washings were necessary. I found that more worms could be obtained by this method than by any other available in Lagos. The Boas sieve method was tried but discarded because the yield of worms was very poor. No attempt was made to count the number of Strongyloides present owing to their small size. They are found in nearly all the stools examined in the laboratory. * For permission to publish I am indebted to Dr. R. BRIERCLIFFE,C.M.G., Director of Medical Services.

646

HELMINTHIASIS. TABLE INTESTINAL

No.

Bmnch°pneum°ni stenosis--bile c-ongenital

lO

11 12 13

duct ..'.'" Patent foramen ovale ......... Bronehopneumonia ......... Lobar pneumonia . . . . . . . . . . . .

..'.'"

Br°nch°pneum°nA l a n c y l o s t o m i a swith i s anaemia . .'.'" Bronchopneumonia ......... Subdural haemorrhage ......... Bronchopneumonia ...... Pneumococeal meningitis'" ...... Sickle-cell anaemia .........

. .'.'"

i Lobar pneumonia . . . . . . . . . . . . Splenic anaemia ......... Bronchopneumonia" ' . ........

Lobar pneumonia . . . . . Bronchopneumonia

Generalized tuberculosis

29 30 31 32 33

Br°neh°pneum°nipu a l m o n a r ytuberculosis Bronchopneumonia ] Pulmonary tuberculosis Bronchopneumonia I Miliary tuberculosis

".'" ..'.'" .........

F. F. M. M. F. M. F.

.

"..'.

Mo F. F. F. F. M. F. M. M. M. F. F. M. M. M. M. M. M. M. F. F. M. M. F. M. F. M. F.

I 'Bronchopneu~nonia " Pa e ym i a i'.i .."." .."." 35 Electrocution ............ 36 i Gangrene of lung . . . . . . . . . . . . 37 ] Bronchopneumonia ......... 38 Siekle-cell anaemia ......... 39 Bronehopneumonia ......... 4O Amoebic colitis . . . . . . . . . . . . 41 Empyaema . . . . . . . . . . . . . . . 42 Multiple injuries . . . . . . . . . . . . 43 Bronchopneumonia ......... i FF."F. 4,1 NephritisG 'eneralize~hr°nit Cuberculosi s ..'-" . .'." .."." 45 46 Bronchopneumonia ......... I 47 Pulmonary tuberculosis . . . . . . . . . 48 49 50 Bronchopneumoni'a ..'. .". . . . ".'" 51 Acute enteritis ............ 52 AsphyxiDi aabetes mell'itus iii "'" ..'.'" ..'.'" 53 54 Generalized tuberculosis "f'. . . . . . . . 55 Chronic peritonitis ......... .56 F. Bacillary dysentery ......... 1 M. 57 Bronchopneumonia ......... 58 i Pulmonary tuberculosis ... M. 59 ! Puerperal septicaemia--septic end'ometriti's F. 6O I Bronchopneumonia ........ . r F.

34

6 8

. .

4 weeks 1 month 1

1 month"8 days 1 15 months 5 8

1

1

8

M.

:ii i'" '//. ".'.. "'.'.. ......... ......... ......... .........

!

I

Total.

Yearl s. ] '~VIonths 1

iii

18 19 20 21 22 23 24

F.

Male. Female.

4 days

MM.M "" j

M.

AT AUTOPSY

Ascaris.

a~e.

Sex.

Cause of death~Anatomical.

HF_.LMINTHS F O U N D

1 1

2 3

1

3

1 1 1 1 2

4 5 6 6

2 2 2 2

6 6 6 9

i

3 3

3 3 3 3

4 4 5 5 5

1

8 1 2 1 1

12 1 3 1 2

4 5 10 11

5 11 7 12

9 16 17

1

3

23 4

10

17

27

3 22

5 50

8 72

1

3

!

4

1

~

i

1105

[

1235 59

3217 75

6 2

ll 6

1

2 6

' 10 6 11

5

6 6

4

16 16 5 4

i i

11o°8 i 1132

j

i

2 2 9

8 18 1 3

! 2

i

P

1! I0 2 27 1 3 2

8

r I !

12

20

31

[

21

6176

I J

1 13

1 13

[

1102

127~

i

16 16 17

!!i 20 20 20 22

7

GUY H. FISK.

647

I,

(120 CASES ARRANGED I N ORDER O r AGE). total

Trichuris.

Necator.

Male. F e m a l e - - Total.

Male.

5

S. haematobium. Taenia.

.4ncylostoma. Total.

4

Male.

Female.

Total.

worms.

60

87

147

|56 1

1

1

11

12 1 3 1 2 10 16 17 26 15 54

16

11 27

8 6 1 1 13

14

20

12

g

12

28

40

11

1

2

26 1

11 1 2

6

6

16

20

9 26 41

16 34 44

3 1

2 14

10

36

5 8 47

1

2

Ii

Present Present

Present Present 4 8 12

5 9 16

8 72 4 23 22 9 40 27 95 6 66 3l 9 13 18 36 35 9 31 9 6 23 21 24 51 53 114 3 13 23 27 50

648

HELMINTHIASIS. TABLE I - -

Case No.

Age. Sex.

Cause of death--Anatomical.

Years. 61 62 63 64 65 66 67 68 69 70 71 79 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 120

Staphylococcal meningitis ...... Tetanus . . . . . . . . . . . . . . . S t a r v a t i o n . . . .... . . . . . . . . Lobar pneumonia ......... Puerperal septicaemia ......... Mercury poisoning ......... Postpartum generalized peritonitis Pulmonary tuberculosis ......... Subdural haemorrhage ......... Intussusception ... ......... Bronchopneumonia .........

-'M. M. F •

F: ...

! M.

... Pyelo-nephritis Compound fracture, skull... Abdominal stab wound--haemoperitoneum Septicaemia following shooting ...... Ruptured ectopic gestation ...... Lobar pneumonia . . . . . . . . . . . . Pulmonary tuberculosis ......... Bronchopneumonia ......... Lobar pneumonia . . . . . . . . . . . . Bronchopneumonia ......... Cardiac failure . . . . . . . . . . . . Drowning . . . . . . . . . . . . . . . Tabes mesenterica--tuberculosis ... Pulmonary oedema ......... Lobar pneumonia . . . . . . . . . . . . Pulmonary tuberculosis ......... Cirrhosis of liver . . . . . . . . . . . . Multiple injuries . . . . . . . . . . . . Volvulus ...... ......... C i r r h o s i s o f l i v e r . . . . .... . . . . Chronic glomerulo-nephritis ...... Pulmonary tuberculosis ......... Lobar pneumonia . . . . . . . . . . . . Post operative pneumonia----amputation... Subacute bacterial endocarditis ...... Lobar pneumonia . . . . . . . . . . . . Chronic nephritis . . . . . . . . . . . . Chronic interstitial nephritis ...... Generalized tuberculosis .........

i

FF*".

~ M.

Cl~'ronic p y t o r i c o b ' a t r u c t i o n , ulcer" Miliary tuberculosis .........

iii

23

24 25 25 25 25 26 26

~ ,I

27

i

27

i

28

/

M.

28

~

!

M. F. M. M. M. M. M. M. F. M. M. F. M. M. M.

2a

1

]

M.

i'

M.

I

M. F. M. M. F. M. M.

i

I

F.

F.

'

F.

M. M. F. F. M. F. F. M. M. F. F. M.

M. M.

29 30

!

30

i

30 30 30

:

3o

[

30 32

I it

34 32

i

35 35 35 39 37 4O 41) 40

4o

40 40 11 42 45 47 49 50 50 50

i L

4 4

J

1

:

i

9

I iI

12 l 2 2

I

5 5 1 1 1 7 10 1 11

~I

13 3 17

2 [

4

:

6

4 7 1 1 2 3 2 6 2

i

I

9

2 2 18 2 6 1

!

i

I

3 4 2 24

:

i

1

i

5 4

4

i

2 11 5

i

1 9 24 7 10

5 4

3 11 5 6

6 13 2 4

11 4 3

:

4 5 1

15 9 4 10

I ~

1

2

i

5 49 1 5

I

a

!

5

2 27 3 16 6 16 2 5

i [

3 49

~ !

] i ~

4 29 7 24 5 10

l

5

:

,

4 7 1

i

ii

1 2 27 2

~o

i

50 50 50 55 55

!

2

, J

1 22 1 13

I

1 8

57 60 60 65 70 71

~

:

i !

Total.

4

3

,

i [

Female.

I

M.

I

Male. 1

i

I M. Septic~aemia f o l l o w i n g tonsi'llitis "'" ~ii Cerebral haemorrhage ......... Miliary tuberculosis ......... Generalized tuberculosis ......... Lobar pneumonia . . . . . . . . . . . . Appendix abscess with peritonitis ... Generalized tuberculosis ......... Lobar pneumonia . . . . . . . . . . . . Pulmonary tuberculosis ......... Lobar pneumonia . . . . . . . . . . . . Multiple injuries . . . . . . . . . . . . Lobar pneumonia . . . . . . . . . . . . Myocardial degeneration ...... Pulmonary tuberculosis ......... Lobar pneumonia . . . . . . . . . . . .

22 23

Months.

3 5 2

i I i

1

3

1

f

7

!

76 3 5

I 437

680

.1,117

GUY H. FISK.

649

(tontinued). Total

Trichuris.

Ancylostoma.

Necator.

S. haematobium. Taenia. n u m b e r of

Total.

Male. 5

L 11 4 2 30 2

] 1

!

2 1 1

10 1 1 59 2

4 21 5 3 89

I

i1

6

:

8

1 9

;

1

1

ll ,l 3

22 5 4

11 1 1

Total.

Male.

18

23

I

2

2

I 8

13 15 1 2 184

I0 ii

4

4

Female.

2 115

69

Female.

Total.

28

12

20

3

1 3

1

worms.

i

Present Present

6 R

I 5

6

6

6

1 16

2 25

1

6 45 12 17 104 14 15 194: 2 3 24 13 5 17 30 11 10

Present 1 ]

29

J I

i

1

!

I i i

2

8

1 2 8

!

54

83

4 5

4 7

2

4i 1 13

4 2

~

3 7 I1 9 2 19

I I !

7 30 5 45 24 11 170

1

1 4

5

9

14

16

32

48

9

25

34

81 8

4 300 27

4 381 35

4 1

1 17 5

1 21 6

26

26

2

2

5

5 1 5 3 20

7 15 2O 1 3 3

8 28 28 1 7 5

1 1

4 1

2

5 3 18

13 1 27 16 5 30

2O 1 38 25 7 49

38

51

89

10

10

20

28

5 34

5 62

3 5 17

4

15

19

1

8 1 1 4 9 63 7

9 1 1 4 11 98 7

1

i 1

1

1

12

28

40

4

22

26

3 1 1

3 I !

26

30

i

2

1

i

1

3

2 10 61 11 10 5 4

305

590

895

26

35

2 35

4

Present 368

1,002

1,370

111

257

368

4

I0 419 65 7 18 56 44 15 12 20 8 24 3 2 110 2 105 101 15 142 5 28 55 31 30 10 38 77 149 22 5 4 3,754

650

HELMINTHIASIS.

The examination for schistosomes was limited merely to determining their presence or absence in the urinary bladder. When suspicious patches were seen in the mucosa of the bladder they were scraped and the material thus obtained was examined microscopically for ova. The worms when collected were placed in 10 per cent. formalin and individually examined. The sex and species of each worm was determined microscopically and the total number for each case recorded. The results are shown in detail in Table I (pp. 646-649). In considering this table the following particulars must be borne in mind. The ages given are correct to a decade only after the first 10 years. After reaching puberty the West African has very little idea of his age and in most cases merely estimates it approximately. The ages shown in the table are based upon that given by the relatives, if any, and that estimated by the pathologist ; hence the frequency of round numbers. The causes of death are those determined at postmortem examination by the pathologist performing the autopsy. Contributory causes of death are not shown as they have no bearing on the present paper. In arranging the Table I found that the age appeared to be associated with the incidence of infestation and the cases have therefore been listed in that order. In all, four species of round worms were found, Ascaris lumbricoides Linn., Trichuris trichiura Linn., Necator americanus Stiles, and Ancylostoma duodenale Dubini. One species of tapeworm, Taenia saginata Goeze, was found. One species of fluke, Schistosoma haematobium Bilharz also occurred. No new or unusual species were seen in spite of careful searching. S. mansoni Sambon is found in Lagos but did not occur in any of the eases examined, so its incidence must be less than 1 per cent. In this series of 120 eases examined postmortem, 3,754 worms were collected --an average of thirty-three worms per person : actually the rate is higher than this. The first six eases in the table are less than 5 weeks old. Since the worms require a month to develop into full grown intestinal parasites none of these babies could possibly have shown an infestation. This leaves 114 eases of whom 103 were infested. That is an infestation rate of just over 90 per cent. Racial habits explain the scanty incidence of infection in children under 1 year and 3 months. The average African mother carries her child on her back until it is in its 2nd year of life; and during this time she also suckles it. Thus the child had little chance of becoming infested. At the end of its 1st year the baby is allowed to walk around and play on the ground with the result that it is exposed to worm infestation daily. At this age it apparently acquires the assortment of worms that it carries to its dying day. After reaching the age of 1 year and 3 months, 96 per cent. of the population are infested. Since it is believed that the average length of life of these worms is from 10 to 15 years, persistent re-infection must occur. Immature worms were found even in the older cases, generally only one or two to a case.

GUY H. FISK.

651

The intensity of the infestation varied from 1 to 419 worms in one person. The greatest number of cases had less than 40 worms. Solitary male and solitary female infestations of all the species of round worms were seen. The largest numbers of worms present in any one case, and the ratio of males to females are shown in Table II. The females usually predominated. In a few cases the males outnumbered the females, but this was exceptional. TABLE I I .

Worm.

L a r g e s t n u m b e r s p r e s e n t in a n y one case.

Sex Ratio. Males.

Females.

Ascaris lumbricoides

76

2

to

3

Trichuris trichiura

89

1

to

2

Necator americanus

184

1

to

3

tlncylostoma duodenale

147

1

to

9.

Numerically the number of Necator infestations exceeds the number of There were 47 cases of Necator infestation with a total of 1,870 and only 22 cases of Ancylostoma infestation with 368 worms in all. This is probably due to the fact that the climate of Lagos is more suited to the development of Necator than of Ancylostoma. The tapeworm infestations were all solitary. Southern Nigerians show a very slight infestation with Taenia saginata as compared with Northern Nigerians who are heavily infested. In my experience amongst hospital patients in Northern Nigeria some 50 per cent. have Taenia infestations. The Southern Nigerians in this present series show only a 3 per cent. infestation. This low rate is probably due to the unbalanced dietary of the Southern Nigerian African who eats very little meat. Although a small number of locally raised pigs are consumed no Taenia solium was seen. Of all these cases only one could be said to have died as a direct result of the worm infestation. This was a child 1 month and 8 days old. It had a very severe anaemia resulting from the hookworm infestation. Since the total number of hookworms present was 156 and there was no other apparent cause of the anaemia I think that these parasites may be assumed to have caused the death of the child, who probably became infested by being placed on the ground in the vicinity of a latrine. Of the 156 worms 9 were Necator and the rest Ancylostoma. This exceptional case shows the density of infestation that may exist in some areas. Although other cases had twice as many Necator worms

Ancylostoma infestations.

652

HELMINTHIASIS.

as the number of .4ncylostoma worms present in this case, none of them showed such an extreme anaemia. This bears out the well-known fact that .4ncylostoma produces a more severe anaemia than Necator. (STITT, 1929; MANSON-BAna, 1935). Two cases (Cases 53 and 67) received treatment at the local hospital. Specimens of stools had been examined beforehand and the ova of Ascaris, Trichuris, and .4ncylostoma had been found. The treatment given was oil of chenopodium alone and this removed the Ascaris infection but had evidently little effect on the other worms since both cases showed an infestation over the mean. Apart from the one mentioned above, no case showed any direct evidence that the worm infestation caused death. In this connection the similar findings of GORDON (1925) on the living natives of Sierra Leone are of interest. He found that as a direct cause of morbidity the helminths were relatively unimportant. Undoubtedly however heavy infestations are an indirect cause of death in many cases. They probably lower the normal resistance of these people so that infections, which in the non-infested European do not cause an abnormally high mortality rate, give rise to a heavy death-rate in Africans by the time they reach the age of 40. These autopsies can be taken as a fair indication of the conditions present in the remainder of the population as regards the infestation with intestinal helminths. It would appear that a public health campaign to educate the native in more sanitary habits would be valuable in reducing the amount of helminthic infestation. REFERENCES. FAUST, E. C. (1930). Human Helminthology : a Manual for Clinicians, Sanitarians and Medical Zoologists. London : Henry Kimpton. GORDON,R.M. (1925). The effect of aneylostome, ascaris and trichuris infections on the health of the West African native. Ann. trop. Med. Parasit., 19, 429. MANSON-BAna,P. (1935). Manson'sTropicalDiseases. 10thEd. London: Cassell&Co. Srn"r, E.R. (1929). The Diagnostics and Treatment of Tropical Diseases. .4 Compendium of Tropical and Other Exotic Diseases. 5th Ed. London : H. K. Lewis & Co.