Studies

C. maculatus
Nigeria
Warrell et al. 1976c: 10 C. maculatus bites; identification: morphological.
Classification:
Local envenoming
1. Extent of the swelling (grade 1–6; scale of Warrell et al. 1974).
2. Intensity of the swelling (according to the method of Reid et al. 1963c).

Case reports

C. maculatus (Nigeria)
Pugh and. Theakston 1987a: 3 C. maculatus bites; identification: ELISA.

C. rhombeatus (Sudan)
Corkill 1956

C. resimus (Sudan)
Corkill 1956

C. defilippii (Southeast Zimbabwe)
Blaylock 1982a

Signs & symptoms

Autopharmacological effects

C. maculatus
Arterial hypotension, tachycardia (cause?) (1/10) (Warrell et al. 1976c).

Local effects

C. maculatus
Local pain 10/10, onset within 30 min after the bite. Local swelling beginning within the same period 3/10. Sooner or later all patients had at least mild swelling. Substantial swelling in only 3/10 patients (percentage circumference increase: 2%, 8%, 12%). Swelling reached a maximum within a day and had resolved completely within 1–4 days. Regional lymph node swelling 4/10. Blistering 0/9, necroses 0/9 (Warrell et al. 1976c).

Intense local pain 3/3, which decreased within days. Local swelling 3/3 (percentage circumference increase: 5.4%, 7.6%, 10%), onset within 15 min (Pugh and Theakston 1987a).

C. defilippii
Mild local swelling 7/8, local swelling that extended to the knee 1/8, necrosis 0/8 (Blaylock 1982a).

Haemostatic effects

C. rhombeatus
Haematuria (no indication of concurrent schistosomiasis) 2/3 (Corkill 1956).

C. resimus
Haematuria (no indication of concurrent schistosomiasis) 1/2 (Corkill 1956).

Haematuria at the time of hospitalisation (2/3) which disappeared spontaneously (no remarks regarding the exclusion of schistosomiasis) (Pugh and Theakston 1987a).

Muscular effects

C. maculatus
Atonic musculature and reduced deep tendon reflexes 1/10 (Warrell et al. 1976c).

Morbidity

No lasting sequelae after a bite, as long as the wound is well cared for.

Case fatality rate

Although bites from this species are common, fatalities are extremely rare. The only fatality reported in connection with a C. rhombeatus bite was most likely due to an anaphylactic reaction with oedema of the larynx/pharynx from sucking venom out of the wound (FitzSimons 1912, cited in: Warrell et al. 1976c).

Laboratory and physical investigations

1. Haemostasis
Studies (Nigeria)
Warrell et al. 1976c (see above for description of study).

Haemostatic parameters

2. Leucocytes
Mild neutrophilic leucocytosis 1/10 (Warrell et al. 1976c).

3. ELISA
Immunological identification of the species: C. maculatus was responsible for 3/31 snakebites. Without this method, it would have been impossible to distinguish this from an Echis carinatus or Bitis arietans bite in the absence of systemic symptoms (Pugh and Theakston 1987a).

Treatment (symptomatic)

1. Immobilisation of the bitten extremity (Warrell et al. 1976c).
2. Paracetamol or codeine phosphate for pain (Warrell et al. 1976c).

Treatment (specific)

No specific antivenom available. However, antivenom generally not necessary. If systemic effects of envenoming occur (arterial hypotension, neurological effects), paraspecific neutralisation may be attempted (C. rhombeatus venom has been neutralised with Polyvalent antivenom, SAIMR, Johannesburg, South Africa) (Christensen 1968, Warrell et al. 1976c).